Scipedia: Documents published in 2017

Automated vehicles: multivariate analysis of drivers' take-over behaviour

Scipedia content — Thu, 28 Jan 2021 17:12:28 +0100

International audience; —This paper presents a study carried out within the context of Level 3 automated driving. It aims to characterize drivers takeover behaviour by exploring quantitative data related to the driver's performance (vehicle data) and qualitative data (user experience expressed in post-activity interviews). For this purpose, several techniques of multivariate analysis were used such as clustering of variables and units. This study illustrates that user experience is associated with the magnitude of actions related to lateral and longitudinal control; positive experience being associated with smoother actions, whereas negative feelings were associated with rougher ones. Furthermore, two main driver's profiles emerged; they are described by two latent variables, one of which is quality of the actions. Future research will investigate the determinants of these profiles.

Are Crowdsourced Datasets Suitable for Specialized Routing Services? Case Study of OpenStreetMap for Routing of People with Limited Mobility

Scipedia content — Thu, 28 Jan 2021 16:59:23 +0100

Nowadays, Volunteered Geographic Information (VGI) has increasingly gained attractiveness to both amateur users and professionals. Using data generated from the crowd has become a hot topic for several application domains including transportation. However, there are concerns regarding the quality of such datasets. As one of the most famous crowdsourced mapping platforms, we analyze the fitness for use of OpenStreetMap (OSM) database for routing and navigation of people with limited mobility. We assess the completeness of OSM data regarding sidewalk information. Relevant attributes for sidewalk information such as sidewalk width, incline, surface texture, etc. are considered, and through both extrinsic and intrinsic quality analysis methods, we present the results of fitness for use of OSM data for routing services of disabled persons. Based on empirical results, it is concluded that OSM data of relatively large spatial extents inside all studied cities could be an acceptable region of interest to test and evaluate wheelchair routing and navigation services, as long as other data quality parameters such as positional accuracy and logical consistency are checked and proved to be acceptable. We present an extended version of OSMatrix web service and explore how it is employed to perform spatial and temporal analysis of sidewalk data completeness in OSM. The tool is beneficial for piloting activities, whereas the pilot site planners can query OpenStreetMap and visualize the degree of sidewalk data availability in a certain region of interest. This would allow identifying the areas that data are mostly missing and plan for data collection events. Furthermore, empirical results of data completeness for several OSM data indicators and their potential relation to sidewalk data completeness are presented and discussed. Finally, the article ends with an outlook for future research study in this area.

Document type: Article

The emerging drive-sharing business : a Glimpse of the future

Scipedia content — Tue, 26 Jan 2021 18:28:02 +0100

This thesis aims to explore car and scooter sharing services, one of the fastest growing and most recent shared mobility services respectively. The main goal is to analyse user’s demographic characteristics, motivations and some of its impacts throughout the time. Due to the different business models, the one-way under free-floating scheme was the selected one to study. In Portugal, more precisely in Lisbon, these services are starting to emerge and gain popularity and as a result, this thesis will analyse how the Portuguese market is responding to this new trend through a comparison with other countries. In-depth interviews and an online questionnaire were conducted. It was concluded that Portuguese users are predominately young, well educated and with relatively lower levels of income. They also revealed to mainly use their own private vehicle as a mean of transportation. Regarding usage motivations, convenience was their greatest motive followed by using as an alternative to public transportation and by interest and curiosity. Nevertheless, only the motive of using as an alternative to public transports shown to be statistically significant to use the services more often. Regarding the impacts, it was verified that some users of private ownership vehicles are reducing their usage, are becoming more aware of their mobility costs, although a disagreement in buying and having a vehicle was verified. Esta tese explora os serviços de compartilhamento de carros e scooters, um dos mais rápidos e recentes serviços de mobilidade compartilhada respectivamente. O objectivo consiste em analisar as características demográficas dos utilizadores, as suas motivações e alguns dos seus impactos verificados ao longo do tempo. De entre os diferentes modelos de negócio, one-way em sistema de livre flutuação foi o selecionado para este estudo. Em Portugal, mais precisamente em Lisboa, estes serviços têm começado a ganhar popularidade, como tal, esta tese irá analisar como o mercado português tem vindo a responder a esta tendência através de uma comparação com outros países. Foram conduzidas entrevistas e questionários online. Concluiu-se que os utilizadores portugueses são predominantemente jovens, educados e com níveis de rendimento relativamente baixos. De igual modo, revelaram que usam o seu próprio veículo como meio de transporte. Quanto aos motivos de uso, a conveniência foi o maior motivo seguido do uso como alternativa aos transportes públicos e interesse e curiosidade. Apenas o motivo de usar como alternativa aos transportes públicos revelou ser estatisticamente significante para usarem mais frequentemente. Em relação aos impactos, verificou-se que alguns usuários de veículos de propriedade privada têm reduzido o seu uso, têm-se tornado mais conscientes com os seus custos de mobilidade, embora se tenha verificado um desentendimento em comprar e ter um veículo.

Electric vehicles and vehicle-to-grid technology. How utilities can play a role

Scipedia content — Tue, 26 Jan 2021 18:23:09 +0100

dverse effects of fossil fuel burning internal combustion engine vehicles has alarmed nations worldwide. With recent technological advancements in electric vehicle industry, governments throughout the world are promoting wider adoption of electric vehicles to mitigate environmental issues. However, increasing popularity of electric vehicles will pose a great threat to existing electric grids due to added load of electric vehicles in power systems distribution network. This study provides solution to stabilize electric grid health in the form of two objectives. First, to develop a fast charging station to reduce consumer anxiety problems related to slow charging stations. The charging setup designed in this study caters two issues; one, to charge EV batteries in minimum time and two, provide utilities with active and reactive power support using EV batteries and charging station, respectively. The second objective of this study is to develop smart charging strategy for the benefit of electric utilities and EV owners. The approach adopted in this study to develop smart charging schedule is based on optimization technique to minimize cost of charging for both, electric utilities and EV owners. This will essentially level utility load throughout the day by providing power to charge EV batteries during off-peak hours, and, on the other hand, utilities will take power from EV batteries for peak power shaving during peak power demand hours of the day. The optimization method adopted in this study is particularly quadratic programming to minimize cost of charging.

Control of a Four In-Wheel Motor Drive Electric Vehicle

Scipedia content — Tue, 26 Jan 2021 18:21:38 +0100

Optimisation de l’ordonnancement de recharges des véhicules électriques

Scipedia content — Tue, 26 Jan 2021 18:16:14 +0100

Our research deals with the problem of the charging scheduling of electric vehicles (EV). The variation in the total power available to load vehicles, user the behaviour constraints and the uncertainties of daily energy demands require an efficient and secure scheduling. We defined five industrial configurations: ACPF (1,2) and ACPV (1a, 1b and 2), each of which corresponds to a set of technical constraints. Studies on formulations, including a conjunctive and a disjunctive, are based on the analysis of the strength of their LP-relaxation. The matrix form of the mathematical formula is composed of a partitioned matrix, which is decomposable by the Dantzig-Wolfe principles. The latter allows us to develop a Branch-and-Price Algorithm for the exact solution of the problem. A deterministic constructive heuristic was then designed for the allocation of the resource, which is very efficient: a quick resolution (less than a second) for a car park with about thirty EVs. Finally, to implement all algorithms in the microprocessor, and to establish a forecasting model and an online scheduling, we have created a stand-alone scheduler, based on the predictive-reactive rescheduling. The research carried out is part of the problems of energy reasoning. They, therefore, can combine with other works, including the smart grid problems; Notre travail de recherche traite de la problématique de l’ordonnancement de recharge des véhicules électriques (VE). La variation de la puissance totale disponible pour charger des véhicules, les contraintes de comportement des utilisateurs et l'incertitude des demandes énergétiques journalières demandent un ordonnancement efficace et sécurisé. Nous avons défini cinq configurations industrielles : ACPF (1,2) et ACPV (1a, 1b et 2) qui correspondent chacune à un ensemble de contraintes techniques. Les études sur les formulations, dont une conjonctive et une disjonctive, reposent sur l’analyse de la force de leurs relaxation-LP. La forme matricielle de la formule mathématique est composée d’une matrice partitionnée, qui est décomposable par le principe de Dantzig-Wolfe. Cette dernière nous permets de développer un algorithme de type Branch-and-Price pour la résolution exacte du problème. Une heuristique constructive déterministe a ensuite été conçue pour l’allocation de la ressource, qui se trouve très efficace : une résolution rapide (moins d’une seconde) pour un parking d’une trentaine VEs. Finalement, pour implémenter tous les algorithmes dans le microprocesseur, et pour établir un modèle prévisionnel et un ordonnancement en temps réel, nous avons créé un planificateur autonome, qui se base sur le réordonnancement prédictif-réactif. Les recherches effectuées font partie des problèmes de raisonnement énergétique. Elles possèdent donc la capacité de se combiner avec d’autres travaux, notamment le problème de smart grid

Analysis of Business Models for EV Fleets in Cites

Scipedia content — Tue, 26 Jan 2021 18:11:08 +0100

This thesis examines the transition from internal combustion engine (ICE) fleets to electric vehicle (EV) fleets. In particular, there is a focus on the economic effects from the point of view of the fleet owner, as well as overall environmental effects. This is accomplished through case studies involving different fleet-based business models and analysing the resulting effects of a transition to EV fleets. Furthermore, comparisons will be made between similar scenarios in two different European cities, namely Barcelona and Stockholm. Additionally, aid and incentives to motivate a change from ICE and EV fleets are explored in detail. The results show annual savings of 4,279.94 EUR/year and 6,352.33 EUR/year for taxi drivers in Barcelona and Stockholm respectively, and 6,405,121 EUR/year and 8,594,734 EUR/year for public bus operators in Barcelona and Stockholm respectively. Furthermore, the results show a reduction in local emissions of 12,727 kg CO2/year for taxi drivers in Barcelona and Stockholm, and 22,835,163 kg CO2/year and 19,134,464 kg CO2/year for public bus operators in Barcelona and Stockholm respectively. Finally, savings for delivery service fleets are shown to range from 18.25 EUR for 4,000 km up to 3,744.25 EUR for 50,000 km. The thesis concludes by acknowledging the large positive environmental effects, while also pointing out that despite the yearly economic savings, there is still a large financial burden associated with a transition to EV fleets. Ways in which this financial burden can be reduced include increasing the annual kilometres driven by vehicles in the fleet, and increasing the difference in cost between electricity and fuel prices.

Factors involved in the adoption ofsustainable mobility product-service systems : The case of KTH Mobility Pool in Sweden

Scipedia content — Tue, 26 Jan 2021 18:08:04 +0100

The transport sector is responsible for large amounts of greenhouse gas (GHG) emissions and dueto the continued growth of both passengers and shopping of goods, these emissions are constantlyincreasing. Globally, 50% of the energy within the transport sector is consumed by passenger carsand commercial vans. Hence, sustainability within mobility is of interest and there are severaldifferent ways to address this issue. One possible solution could be car sharing which is a mobilityproduct-service system (PSS) where the private car is replaced by rental cars. However, diffusionof such PSSs is slow, and they are still limited to small niche markets.In this thesis, a dataset from the research project KTH Mobility Pool (KMP) has been analysed.KMP involved a mobility PSS in which electric vehicles (EVs) were integrated with a digitalbooking system, in a shared use system. The users tried out the PSS during a six-months trialperiod. The aim with this thesis was to identify different factors involved in the adoption of newsustainable mobility PSS. During the thesis work additional research questions emerged regardingthe motivation to participate in trials within new sustainable mobility PSS and what impact thetrial had on the users from an environmental perspective. An exploratory and inductive researchapproach was used, with a data analysis influence by grounded theory. Moreover, the thesis workinvolved a mixed method approach since the analysed dataset derived from interviews, surveysand workshops with the KMP users.Through the comparison of the analysed data and existing literature some conclusions could bedrawn. Common motivators for participating in the KMP trial were the opportunity to try out anew technology, saving money and interest in technology, cars and the environment. Five factorsof importance during the trial could be identified: convenience, car ownership, economy,environment, and safety. The impact of the trial on the users was an increased environmentalconsciousness where the users became more aware of their car usage and felt more environmental.Moreover, the trial also gave the users a more positive attitude towards EVs concerning thedevelopment of the EV market, their range and practicality. In conclusion, more research is neededto unfold and establish a complete and holistic view of the adoption of sustainable mobility PSS.However, the findings in this thesis work have answered some of the questions regarding theadoption of sustainable mobility PSS, which can be useful for future trials. Transportsektorn ansvarar för en stor mängd av växthusgasutsläpp och då både antalet passagerareökar och varuhandeln växer, så ökar även utsläppen konstant. Globalt så går 50% av energin inomtransportsektorn till personbilar och kommersiella fordon. Således är hållbarhet inom mänskligtransport viktig och det finns flera sätt att angripa detta dilemma. En möjlig lösning är samåkning,vilket är ett produkt- och tjänstesystem (PSS) där den privata bilen ersätts med en hyrbil. Dock såär spridningen av sådana PSS långsam och de är fortfarande begränsade till små nischmarknader.I detta examensarbete har en datauppsättning från forskningsprojektet KTH Mobility Pool (KMP)analyserats. KMP involverade ett PSS för mänsklig transport, i vilket elbilar var integrerade medett digitalt bokningssystem, i ett gemensamt användningssystem. Detta PSS användes utavanställda på ett tillverkningsföretag till och från jobbet samt under arbetstid, under en sex månaderlång försöksperiod. Målet med examensarbetet var att identifiera de olika faktorer som ärinvolverade i införandet och användandet av nya hållbara PSS för mänsklig transport. Underarbetets gång så dök ytterligare frågeställningar upp angående vad som motiverade användarna atttesta på PSS för mänsklig transport, och hur testprocessen påverkade dem ur miljösynpunkt. Enundersökande och induktiv forskningsmetod användes, med en dataanalys inspirerad av grundadteori. Examensarbetet involverade dessutom en blandning av både kvalitativa och kvantitativametoder eftersom den analyserade datauppsättningen bestod av intervjuer, undersökningar ochworkshops med KMP-användarna.Genom jämförelse av data som analyserats med befintlig litteratur, kunde vissa slutsatser dras.Vanliga motivationsfaktorer för att delta i KMP-projektet var möjligheten att prova på ny teknik,spara pengar och intressen för teknik, bilar och miljö. Fem faktorer av betydelse under försöketkunde identifieras: bekvämlighet, bilägande, ekonomi, miljö och säkerhet. Effekten av försöket påanvändarna var en ökad miljömedvetenhet där användarna blev mer medvetna om sinbilanvändning och kände att de gjorde något gott för miljön. Dessutom gav testet användarna enmer positiv inställning till elbilar angående marknadens utveckling, elbilars räckvidd och deraspraktiska egenskaper. Sammanfattningsvis behövs mer forskning för att utveckla och upprätta enhelhetsbild över de faktorer som är involverade i införandet och användandet av ett hållbart PSSför mänsklig transport. Dock så har detta examensarbete svarat på frågor angående några av dessafaktorer, vilket kan vara användbart för framtida projekt.

Look-ahead control for fuel-efficient and safe heavy-duty vehicle platooning

Scipedia content — Tue, 26 Jan 2021 18:07:48 +0100

The operation of heavy-duty vehicles at small inter-vehicular distances, known as platoons, lowers the aerodynamic drag and, therefore, reduces fuel consumption and greenhouse gas emissions. Tests conducted on flat roads have shown the potential of platooning to reduce the fuel consumption of about 10%. However, platoons are expected to operate on public highways with varying topography alongside other vehicles. Due to the large mass and limited engine power of heavy-duty vehicles, road slopes have a significant impact on feasible and optimal speed profiles. For single vehicles, experiments have shown that optimizing the speed according to the road profile resulted in fuel saving of up to 3.5%. The use of such a look-ahead control framework is expected to lead to large benefits also for platooning. This thesis presents the design of safe and fuel-efficient control of heavy-duty vehicle platoons driving on realistic road profiles. The scenario where the platooning vehicles cooperate to optimize their overall fuel-efficiency is studied together with the scenario where the vehicles do not explicitly cooperate. First, we propose a control architecture that splits the cooperative platooning control problem into two layers. The top layer computes a reference speed profile that ensures fuel-efficient operation of the entire platoon based on dynamic programming. The bottom layer relies on model predictive control to safely track the reference speed. Simulations show the ability of the proposed controller to save up to 12% of fuel for following vehicles compared to existing platoon controllers and to safely react to emergency braking of the leading vehicle. Second, we propose a gear management layer that fits in the cooperative platooning control architecture and explicitly takes the gear selection into account. The underlying optimal control problem aims at minimizing the vehicle fuel consumption and the reference tracking deviations. Simulations indicate how this formulation outperforms existing alternatives, both in terms of fuel-efficiency and tracking error. Third, we address non-cooperative platooning by proposing a vehicle-following controller suitable for fuel-efficient control of heavy-duty vehicles. The proposed controller explores both the benefits given by the short inter-vehicular distance and those given by pulse-and-glide, i.e., alternating traction and coasting phases. A simulation study suggests fuel saving of up to 18% compared to the single vehicle case, and up to 7% compared to when a constant-distance vehicle-following controller is used. Last, we propose a vehicle-following controller aimed at exploiting long preview of the preceding vehicle trajectory by directly manipulating the inputs of low-level vehicle controllers. This is achieved through a model predictive controller that uses a short prediction horizon and includes a terminal state set that incorporates preview information about the preceding vehicle. Experiments indicate the ability of the controller to avoid unnecessary braking, while simulations show behavior similar to the optimal control behavior. "p"QC 20180416

Logística urbana de cargas em áreas centrais

Scipedia content — Tue, 26 Jan 2021 18:03:50 +0100

globalização aprofundou suas estratégias capazes de fomentar a competição global e de definir os agentes hegemônicos na disputa de territórios. Nesse cenário, as cadeias logísticas têm ganhado força no (re)ordenamento territorial, impactando a política, a economia e até mesmo a cultura de consumo da sociedade. Apesar de sua importância, as cadeias logísticas também contribuem para o surgimento e/ou intensificação de inúmeros problemas recorrentes principalmente nas áreas centrais, como congestionamentos, poluição ambiental, aumento dos ruídos e acidentes de trânsito. Quanto à atuação do Poder Público e das empresas no território brasileiro, ela tem se pautado cada vez mais na racionalidade e eficácia dos fluxos materiais e imateriais, de modo que a moderna Logística Urbana surge como uma questão-chave para o desenvolvimento socioeconômico. Assim, o objetivo deste trabalho consiste em analisar a logística urbana de cargas em áreas centrais e, a partir de suas premissas, explorar as relações de planejamento urbano. Com isso pretende-se definir estratégias para reparar e modernizar a qualidade da infraestrutura de transporte de cargas, bem como redirecionar as políticas, os programas e os projetos de investimento municipal, tomando como estudo de caso a área central de Uberlândia. Para o atingimento do objetivo central, a metodologia utilizada consistiu em pesquisa bibliográfica e de campo, visitas em câmaras técnicas, participação em eventos, entre outros recursos. Como resultado, identificamos problemas de uso e ocupação do solo, estacionamentos irregulares, dificuldade de acesso dos veículos de carga, entre outros na zona central de Uberlândia. Partindo desse diagnóstico, apresentamos diretrizes de nível tático para a melhoria das atividades de transporte de cargas e operações logísticas em áreas centrais. La globalización ha profundizado sus estrategias para promover la competencia global y para establecer los agentes hegemónicos en los territorios de disputa, donde las cadenas de suministro han cobrado fuerza en la (re) La planificación, que inciden en la política, la economía y la cultura de consumo, incluso la sociedad. A pesar de su importancia, las cadenas logísticas han contribuido a la aparición y / o intensificación de numerosos problemas, principalmente vistos en las áreas centrales, tales como la congestión, la contaminación ambiental, el aumento de ruido, accidentes de tráfico, entre otros. En este contexto, el papel del gobierno y de negocios en Brasil se ha basado cada vez más en la racionalidad y la eficiencia de los flujos de materiales e inmateriales y la logística moderna urbana emerge como un tema clave en el desarrollo socio-económico. El objetivo de este estudio es evaluar y analizar la logística urbana de mercancías en las zonas centrales, y desde sus instalaciones explorar sus relaciones de planificación urbana, para definir estrategias para mejorar y elevar la calidad de la infraestructura de transporte de mercancías así como desviar las políticas, programas y proyectos de inversión municipal, tomando como caso de estudio la zona central de Uberlândia. En la consecución del objetivo principal, la metodología utilizada, que consistía en la literatura, la realización de una investigación de campo, visitas en los consejos técnicos y eventos, entre otros se convirtieron satisfactoria. Como resultado, se presenta directrices estratégicas y tácticas para mejorar el transporte de cargas de las actividades y operaciones de logística en las zonas centrales. Dissertação (Mestrado)

CHINA’S POWER SECTOR DECARBONIZATION: MODELING EMISSION REDUCTION POTENTIAL, TECHNICAL FEASIBILITY AND COST EFFICIENCY OF INTER-SECTORAL APPROACHES

Scipedia content — Tue, 26 Jan 2021 18:03:15 +0100

China has become the “world’s factory” and lifted up several millions of people out of poverty through decades of economic reforms. However, this socio-economic development, fueled by coal, has heavily impacted the energy landscape and the environment. Today, China is both the global largest polluter and largest developer of clean energy systems. The unprecedented extent of the country’s power sector challenges and opportunities requires to refine current capacity planning models to better inform policy making. Focusing on climate urgency, this study contributes to filling this need by proposing new modeling frameworks. These models offer a fine-grain analysis of China’s power sector decarbonization potential, by grounding long-term electricity mix expansion planning into inter-sectoral development. Using large datasets of technical, economic and social factors, levers of the clean power transition are analyzed by quantifying and comparing their decarbonization potential, technical feasibility, and cost efficiency over time and across regions and resources. The first lever lies in the coordinated expansion of a low-carbon electricity grid, resilient to renewable energy intermittency and disparities in space and time between energy resources and demand. The high-resolution model SWITCH-China is used to explore optimal capacity expansion pathways for China’s electricity mix under various low-carbon policies. Results show that, while natural gas can become a bridge between the current coal-dominated grid and a future clean electricity mix, a deep decarbonization scenario mostly relies on the concomitant deployment of nuclear—inland, encouraged by advanced nuclear technology development—, wind, solar, energy storage, coal with carbon capture and storage, and an expanded transmission network. Meeting this long-term decarbonization goal increases electricity costs significantly compared to an unconstrained scenario. A modular approach, adaptable to traditional cost-minimizing tools used by planning agencies, is proposed to reduce uncertainty of future technological costs as well as costs resulting from electricity generation intermittency. The model finds that there exist alternatives to the least-cost strategy, which present slightly higher overall electricity costs, but much lower risks. In particular, given the predominance of fossil fuel in the current electricity mix, the deployment of low-carbon systems decreases the overall risk on future costs through diversification, even by accounting for increased operational complexity resulting from renewable energy intermittency. The second lever is the integration of linkages between power and water supply into the optimization framework, as China currently faces both severe water shortages and severe water pollution. Results show that, while total costs of the South to North Water Transfer Project are 2.5 times lower than nuclear desalination, the latter emits six times less CO2. In addition, fresh water from nuclear desalination is shown to be affordable even to the poorest households. Challenges posed by the construction and operation of interregional water diversion suggest that it should only be used in dry inland areas, while low-carbon desalination could be developed at larger scale near coastal economic centers. The DESEC model is developed to explore controllable desalination, powered by nuclear, wind, or solar energy, as a mean to alleviate water scarcity in coastal regions while enabling the wide deployment of a low-curtailment clean power base. Desalination, used as a deferrable load, can transform two low-value products, seawater and excess power from non-dispatchable energies, in a high-value product, fresh water. The DESEC model finds that the North China Grid region’s entire water deficit—61.4 billion m3—can be met entirely by deferrable desalination with a total cost of about $1.5/m3, less than the global average water price. Analyses conclude that there exist local alternatives to current national-scale power and water diversion projects, more adapted to regional characteristics, less prone to risks and disruptions. The third lever is the electrification of urban passenger cars, as the sector is poised for massive expansion in the next decade. Findings show that the near-term deployment of electric vehicles cannot be enabled by technology cost decrease alone. If the current impact from favorable policy is maintained but not amplified, CO2 emissions from urban passenger cars will peak around 2040, or ten years past the official 2030 carbon peak target. In fact, although it demonstrates higher costs in the near term, large-scale vehicle electrification is the least-cost, least-CO2-emission pathway for China’s urban transportation expansion in the long run. Generally, model results reveal that massive investment is needed in R&D and infrastructure capacity deployment, and that utilities and institutions must be reformed to manage resources rationally, hand-in-hand. Many of the studied decarbonization options have not reached a mature stage or have not been deployed at utility-scale today, and future work is required to better account for modeling and data uncertainty. Yet, models developed, used and presented in this study all reveal the existence of viable, cost-efficient options to enable meaningful decarbonization while alleviating water scarcity and air pollution. These strategies can only be achieved by combining central-scale coordination with local-scale implementation, to take advantage of China’s diverse and rich territory while minimizing risks. This dissertation provides new approaches for identifying realistic, affordable capacity expansion pathways, rigorously designed by mathematical optimization and large datasets, to reduce CO2 emissions related to the power sector in line with climate targets. The impact that China will have on climate change and its ability to ensure its long-term sustainability will depend on actual decisions and actions undertaken by governmental and private entities. The success of the clean energy transition is contingent on the country’s ability to encourage technological, economic and institutional innovation.

Algoritmos de Controlo para o Carregamento de Veículos Elétricos em Edifícios Residenciais

Scipedia content — Tue, 26 Jan 2021 17:59:34 +0100

Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia A eletrificação do setor dos transportes irá desempenhar um papel fundamental no futuro de cidades mais inteligentes e mais sustentáveis. Devido à crescente adoção de veículos elétricos (EVs), se o carregamento não for controlado, poderão surgir eventuais problemas na rede elétrica, tal como sobretensões levando a perdas de energia. Assim, torna-se necessário a criação de estratégias de carregamento mais inteligentes.Esta dissertação apresenta um algoritmo inteligente de controlo de carregamento (SCMA) que simula o carregamento de um EV, numa residência, de acordo com as preferências do utilizador, bem como as da rede. Este algoritmo permite ao utilizador poupanças de energia e beneficiam, simultaneamente, a rede elétrica e o ambiente. Para o seu funcionamento, considera-se que a residência em causa tem uma tarifa energética variável no tempo, de hora em hora. Assume-se também que os dados da variação do preço da eletricidade, da previsão de procura e da geração energia renovável são comunicados ao SCMA.Os SCMA foram simulados de acordo com três objetivos: minimizar o custo de carregamento, minimizar o impacto ambiental e suavizar o diagrama de carga. Par tal, os algoritmos priorizam ou os intervalos de tempo com menor custo de eletricidade, aqueles com maior percentagem de energia renovável, ou ainda os que apresentem maior disponibilidade de potência. Depois, os algoritmos foram simulados para vários casos de estudo.Por último, os cenários de carregamento otimizado foram comparados entre eles e com um caso de carregamento não otimizado. O SCMA foi bem sucedido na otimização do carregamento do EV sob todos os objetivos. The transport electrification will play an important role in future smarter and more sustainable cities. Due to the increasing adoption of electric vehicles (EVs), if the charging cycles are not managed, a number of grid related issues, such as overload, could arise, which can lead to power outages. Thus, smarter charging strategies are required.This dissertation presents smart charging management algorithm (SCMA) that simulate the charging of the EV according to the user’s preferences, as well as the grid’s requirements. Such algorithm allows further energy savings to the consumer, whilst benefiting the grid and the environment. It is considered that the residential dwelling is operating under time-varying electricity prices, that change on an hourly basis. This work assumes that electricity pricing variations, the load forecast and the renewable energy generation data are provided to the SCMA.The SCMA was simulated under three objectives: to minimize the charging cost, minimize the environmental impact and to flatten the load profile. In order to do this, the algorithms either prioritize the time slots with the lowest electricity price, or the ones with higher RES share, or the ones with more available power, respectively. Then, the algorithms were tested for a series of case studies.Lastly, the optimized charging scenarios were compared among them and to an unmanaged charging scenario. The SCMA successfully optimized the EV’s charging cycles under any objective. - - - - - -

Impact of Speed on Vehicle Safety on Urban Arterial Roadways

Scipedia content — Tue, 26 Jan 2021 17:57:43 +0100

An analysis of active transport travel behavior of young adult : a case study of university students of Grenoble

Scipedia content — Tue, 26 Jan 2021 17:53:28 +0100

Physical activity in any means is important for all, irrespective of age and gender, however, shift from the adolescence to adulthood is considered to be more susceptible to gain obesity and health risks. It is agreed that physical activity patterns, established in young adult life stage, are likely to endure for a long time. So, to promote active travel behavior and improve health condition of the future adults, young adult is an important life stage to intervene. The purpose of this study is to explore how individual, social, and environmental factors do influence the commuting behavior of emerging adults primarily. Grenoble city is selected as a case for the study. Two institutions (Institut d'Urbanisme de Grenoble (IUG) and Institut de géographie alpine (IGA)) of Université Grenoble Alpes and École nationale supérieure d'architecture de Grenoble (ENSAG) are selected to study the students aged 18 to 25. The association between different factors and active travel behavior of the students are analyzed using both spatial and statistical analysis techniques. For spatial analysis, a face to face interview is conducted through spatial mapping (geocoding) and three spatial attributes (land use, land use mix and public transport service area) are considered as the basis for the analysis. For statistical analysis, in addition with the face to face interview, an online questionnaire survey is conducted, focused on three types of factors (socio-demographic, travel, and environmental factors) associated with the active travel behavior of young adults. Both descriptive statistics and binary logit model are used for this purpose. The findings from these two analyses reveal that there are significant relationships exist between different socio-demographic, travel and environmental factors and students’ active travel behaviors. Besides, this study also explores the potentiality of different alternative strategies adopted in the city of Grenoble and gaps of these interventions from the perspective of students. Therefore, this research justifies the importance of young adult life stage for the promotion of active transportation and potentiality of their participation in research works.

IN THE MIDDLE OF EVERYWHERE : A Hypothetical Studies for a New Travel Hub Between Europe and Asia

Scipedia content — Tue, 26 Jan 2021 17:49:22 +0100

The development of air transport industry contributes to the economic growth worldwide. It evolves from a luxury form of transportation to an affordable and quick way to move between places. The airline operation model evolves from a traditional point-to-point operation to a hub-and-spoke model, where airline funnels passenger through a centralized location called hub. This model, while reducing operational cost and increasing connectivity, is also adding more time and distance to one’s journey. The development in aircraft technology however, allows airline to by-pass the traditional hub and fly directly to their destination with a longer-range aircraft with a low capacity, somehow returning to the original operational model of point-to-point flight. However, this new type of aircraft also allows airline to reach a smaller destination that didn’t justify the use of the high-capacity aircraft that was traditionally used on this long-haul flight. Aside from the lower acquisition cost, this smaller aircraft also burns less fuel and reduce the airline financial risk. The study was focused on locating a new hypothetical hub to connect Europe with Eastern Asia, the top two aviation market by passenger number. This new hub will be strategically located between the two markets, unlike the current Middle-Eastern hub that requires a significant detour. The Buffer Tool that is available in ArcGIS will be utilized to draw a radius between each airport in the study area, where the radius’ values were based on the range of the Airbus A321NEO (New Engine Option). Area with the most intersection will be further analyzed to determine the most reasonable location for the new hub, based on the airport infrastructure and the country’s socio-economic index. The result of this study shows that the Central Asian region has the most overlapping circle, with the city of Almaty in Kazakhstan emerged as the most potential location for this new hub. The geographical advantage, backed by a relatively strong economy and stable socio-political condition, made Almaty left the other candidates behind.

Control Algorithm Design, Testing, and Use Cases for the INSTAR [INertial STorage And Recovery] System. A Flywheel-Based Dedicated High-Power Energy Storage System for Improved Hybrid Vehicle Fuel Efficiency and Performance with Special Application in Urban Commercial Vehicles

Scipedia content — Tue, 26 Jan 2021 17:46:16 +0100

This thesis describes the design of control algorithms, modelling, testing, and analysis of use cases of the INSTAR system, a dedicated high-power, low cost energy storage system designed to increase energy efficiency and performance in hybrid vehicles, with special application in urban commercial vehicles. The system is intended to be combined with an electrochemical battery and small energy generator to provide 3 distinct magnitudes of power delivery and absorption to the traction motors. The advantages of such a system would be decreased generator size, decreased component size, and potentially increased battery service life. Flywheel control algorithms were developed and tested to absorb excessive electrical energy during regenerative braking, as well as to augment electrochemical battery power during vehicle accelerations. During laboratory testing battery charging currents reaching the battery were controlled through modulation of flywheel throttle signals. These algorithms were applied in road driving conditions to decrease vehicle energy use by 8.9 percent over a predetermined acceleration and deceleration event while decreasing the charging rate of the battery. Laboratory testing showed potential to reduce battery discharge rate during acceleration events by pre-charging the flywheel so that it may be discharged during the acceleration event. Road tests demonstrated that energy use could be reduced by 2.6% over a pre-determined acceleration and deceleration event while simultaneously reducing the magnitude of battery discharge current by around 15%. Such a system has use in urban vehicles where much of the vehicle driving is in stop and go type traffic. These vehicles typically have a large internal combustion engine to accelerate the vehicle from a stop. The INSTAR system may be able to reduce the engine output requirement while still providing the same performance. The INSTAR system is particularly applicable in commercial vehicles where fully electric vehicle may not be practical.

Aplicación de métodos algebraicos para la estimación del estado de carga de baterías de litio en aplicaciones de vehículos eléctricos

Scipedia content — Tue, 26 Jan 2021 17:43:14 +0100

Resumen: En el presente documento se describe el desarrollo, la implementación y los resultados obtenidos al aplicar una estrategia de estimación en línea del estado de carga de baterías de litio. La estrategia de estimación presentada involucra técnicas algebraicas para realizar la estimación de la tensión de circuito abierto, y se apoya en el clásico método de Newton para estimar el estado de carga. En este trabajo se desarrolla un modelo matemático para predecir el comportamiento de la batería. También se diseña y construye una plataforma de pruebas en donde se validan las estrategias desarrolladas. Adicionalmente, se presentan los resultados obtenidos y se realiza una comparación con otras técnicas de estimación del estado de carga. Abstract. This document describes the development, testing and results of applying an state of charge online estimation strategy for lithium batteries. The estimation strategy involves algebraic techniques in order to estimate the open circuit voltage, and make use of the classic Newton’s method to estimate the state of charge. In this work, a mathematical battery model are developed. Moreover, the design and construction of a testbench to validate the strategies are presented. In addition, the test results and the comparison between other state of charge estimation strategies are shown.

Development of a Body for a Pneumatic Crawler for Radioactive Waste Pipelines

Scipedia content — Tue, 26 Jan 2021 17:42:25 +0100

Business Model Innovation - the solution for EV producers : A qualitative study on Business Model Innovation in the context of Electric Vehicles int he Nordics

Scipedia content — Tue, 26 Jan 2021 17:41:13 +0100

Electric Vehicles are a growing trend globally and are currently disrupting the conventional automotive industry, therefore firms in the sector need new business models around their new value propositions. The concept of business model innovation presents an interesting point of view towards the challenges those firms face and provide possible solutions for them. The literature on this relatively new topic is scarce and needs more cumulative empirical research. We engage in a multiple-case study and explore how entrepreneurial and incumbent electric vehicle companies in the Nordics use BMI to overcome their biggest challenges and advance the development of the sector. With our findings, we provide an insight of some of the newest advancements in the EV technology, investigate what are the key antecedents, moderators, and outcomes of the BMI process for the researched companies and build on the existing literature on the topic. Finally, practitioners can gain a better understanding of the concepts of BM and BMI process and their importance for surviving in the dynamic electric vehicle market.

Mobility and the Energy Transition: A Life Cycle Assessment of Swiss Passenger Transport Technologies including Developments until 2050

Scipedia content — Tue, 26 Jan 2021 17:40:26 +0100

The transport and electricity sectors are in the midst of major changes in an attempt to limit climate change and air pollution problems. In the coming decades conventional fossil fuelled vehicles are expected to be replaced with electric powertrain vehicles, resulting in increased electricity demand by the transport sector. At the same time, the electricity sector is also in upheaval due to policy decisions to move away from fossil and, in many locations, nuclear energy sources towards renewables such as hydro, wind, and solar. Rightfully so, many questions have been raised in the scientific literature and media regarding the environmental benefits of these new vehicle technologies and how the different energy chain and vehicle options compare. The goal of this thesis is to analyse the environmental burdens of current and future (2050) passenger transport technologies in Switzerland while taking into account future developments of the Swiss and global electricity sectors. I use the methodology of Life Cycle Assessment (LCA) to quantify the environmental burdens from current and future passenger transportation by motorcycle (Chapter 3), aircraft (Chapter 4), urban bus (Chapter 5), and passenger car (Chapters 6 and 7) for different refuelling/ recharging energy chains. Vehicle performance is modelled using a consistent framework across powertrain types to ensure fair comparison. Road vehicle energy consumption is calculated using a physics-based model that simulates operation using internationally harmonised driving cycles. This model is calibrated with real energy consumption data for each vehicle and powertrain type. This allows prediction of future vehicle performance by estimating the potential future changes for each input parameter, such as internal combustion engine efficiency or lithium ion battery cell energy density. In Chapter 6 I extend this model to enable Monte Carlo analysis and global sensitivity analysis to show that the electricity used for charging electric vehicles is the largest source of global variability of the environmental burdens of electric cars, though vehicle size, lifetime, driving patterns and battery size also strongly contribute to variability. I also further adapt the model using exponential smoothing of driving cycles and wind tunnel measurement results to show that future autonomous and connected vehicles could consume roughly 10% less energy per kilometer than comparable human driven vehicles. I also incorporate future developments of the electricity sector into the calculations by integrating scenario results from the IMAGE integrated assessment model into the ecoinvent LCA database using the open source software package Wurst that I helped to create. Two scenarios from the IMAGE model are used for the development of the future electricity sector for 26 global regions: Baseline may be considered a business as usual type scenario, while ClimPol represents the aggressive decarbonisation that would be consistent with a likely probability of achieving the 2°C target. This is a significant development in the field of prospective LCA and I am able to show that without these changes to the background database, future climate burdens could be overestimated by up to 75% in the ClimPol scenario. In Chapter 8 I compare different passenger transport modes for the Baseline and ClimPol electricity scenarios in the year 2050. Results are generally quite consistent across vehicle types. The introduction of battery electric vehicles is found to provide clear climate benefits compared to conventional combustion vehicles for all vehicle types as long as the electricity used for charging has carbon content similar to or less than that of a modern natural gas power plant. Switzerland’s current and future electricity mix for all likely scenarios easily meets this requirement, so a robust conclusion may be drawn that battery electric vehicles of all types should be supported in Switzerland from a greenhouse gas (GHG) emission point of view. When other environmental impact categories are considered the superiority of battery electric vehicles is less clear, though hard conclusions cannot yet be drawn due to methodological limitations. I also develop a simple fleet model to estimate the total life cycle emissions caused by the Swiss passenger transport sector. Fleet model results for 2050 show that if all road vehicles are powered by battery electric powertrains the total Swiss domestic passenger transport related life cycle GHG emissions are 47% lower in the Baseline scenario and 72% lower in the ClimPol scenario compared to 2017 emissions. Similar model results for fleets of fuel cell vehicles show 34% and 66% improvement respectively, while a fleet of hybridized combustion vehicles would enable reductions of 31% and 41% respectively. When international air transport is also included in the future fleet assessment it is found to dominate the results in some categories, especially climate change and cumulative energy demand. Future growth in air transportation demand is expected to negate all climate change reductions made in ground transportation, leaving total sector emissions in 2050 roughly similar to current emission levels. If air transport demand continues to grow according to historic rates and future projections, it will become one of the most important sources of greenhouse gases in the future, as technical improvements are expected to be outpaced by growth in demand. The only remaining solutions appear to be shifting continental transport demand to electric train, which has comparatively low impacts, or curbing demand growth. There are three main outcomes of the thesis. The first is the wealth of data published as extensive supporting information in each of my publications. These models and results should be used as inputs by energy and transport modellers as well as fed into life cycle assessment databases. The second is the open source software package Wurst that can be used to create modified versions of the ecoinvent database. This methodology has the potential to greatly improve the quality of prospective LCA. The third outcome of this thesis is the report (Chapter 7) that I helped to prepare for the Swiss Federal Office for Energy. The summary of this report is expected to reach the highest level of decision makers in the country and help inform Swiss policy regarding the energy transition.

Electrochemical Li-Ion battery modeling for electric vehicles

Scipedia content — Tue, 26 Jan 2021 17:40:10 +0100

The future development of electric vehicles is mostly dependent of improvements in battery performances. In support of the actual research of new materials having higher performances in terms of energy, power, durability and cost, it is necessary to develop modeling tools. The models are helpful to simulate integration of the battery in the powertrain and crucial for the battery management system, to improve either direct (e.g. preventing overcharges and thermal runaway) and indirect (e.g. state of charge indicators) safety. However, the battery models could be used to understand its physical phenomena and chemical reactions to improve the battery design according with vehicles requirements and reduce the testing phases. One of the most common model describing the porous electrodes of lithium-ion batteries is revisited. Many variants available in the literature are inspired by the works of prof. J Newman and his research group from UC Berkeley. Yet, relatively few works, to the best of our knowledge, analyze in detail its predictive capability. In the present work, to investigate this model, all the physical quantities are set in a dimensionless form, as commonly used in fluid mechanics: the parameters that act in the same or the opposite ways are regrouped, and the total number of simulation parameter is greatly reduced. In a second phase, the influence of the parameter is discussed, and interpreted with the support of the limit cases. The analysis of the discharge voltage and concentration gradients is based on galvanostatic and pulse/relaxation current profiles and compared with tested commercial LGC cells. The simulations are performed with the software Comsol® and the post-processing with Matlab®. Moreover, in this research, the parameters from the literatures are discussed to understand how accurate are the techniques used to parametrize and feed the inputs of the model. Then, our work shows that the electrode isotherms shapes have a significant influence on the accuracy of the evaluation of the states of charges in a complete cell. Finally, the protocols to characterize the performance of commercial cells at different C-rates are improved to guarantee the reproducibility.; Le développement futur des véhicules électriques est lié à l’amélioration des performances des batteries qu’ils contiennent. Parallèlement aux recherches sur les nouveaux matériaux ayant des performances supérieures en termes d'énergie, de puissance, de durabilité et de coût, il est nécessaire développer des outils de modélisation pour : (i) simuler l'intégration de la batterie dans la chaine de traction et (ii) pour le système de gestion de la batterie, afin d'améliorer la sécurité et la durabilité. Soit de façon directe (par exemple, la prévention de surcharge ou de l’emballement thermique) soit de façon indirecte (par exemple, les indicateurs de l’état de charge). Les modèles de batterie pourraient aussi être utilisés pour comprendre les phénomènes physiques et les réactions chimiques afin d'améliorer la conception des batteries en fonction des besoins de l’utilisateur et de réduire la durée des phases de test. Dans ce manuscrit, un des modèles les plus communs décrivant les électrodes poreuses des batteries au lithium-ion est revisité. De nombreuses variantes dans la littérature s’inspirent directement du travail mené par le professeur J. Newman et son équipe de chercheurs à l’UC Berkeley. Pourtant relativement peu d’études analysent en détail les capacités prédictives de ce modèle. Dans ce travail, pour étudier ce modèle, toutes les grandeurs physiques sont définies sous une forme adimensionnelle, comme on l'utilise couramment dans la mécanique des fluides : les paramètres qui agissent de manière identique ou opposée sont regroupés et le nombre total de paramètres du modèle est considérablement réduit. Cette étude contient une description critique de la littérature incluant le référencement des paramètres du modèle développé par le groupe de Newman et les techniques utilisées pour les mesurer, ainsi que l’écriture du modèle dans un format adimensionnel pour réduire le nombre de paramètres. Une partie expérimentale décrit les modifications de protocoles mis en œuvre pour améliorer la reproductibilité des essais. Les études effectuées sur le modèle concernent d’une part l’identification des états de lithiation dans la cellule avec un attention particulière sur la précision obtenue, et enfin une prospection numérique pour examiner l’influence de chaque paramètre sur les réponses de la batterie en décharge galvanostatique puis en mode impulsion et relaxation.

Improving an open source geocoding service

Scipedia content — Tue, 26 Jan 2021 17:36:40 +0100

There are many map providers on the market today. Anyone who wishes to use a licensed map-service in an application has to pay a license fee. This fee can become a big expense and affect the price that the end costumer has to pay.This thesis has investigated in how to set up and improve an open source geocoding service for it to measure against a licensed map-service. Geocoding is the technique of having an input address and returning a position which consists of a latitude and a longitude coordinate. The investigation has been done by implementing an open source solution as a proof of concept with the goal to answer the question to which extent is it feasible to develop an open source geocoding service to be as fast accurate and complete as a licensed map service.The open source solution has been developed in collaboration with TaxiCaller Nordic AB. In the implementation the Pelias project has been used as a geocoder together with map data from the datasets of OpenStreetMap and Who’s On First and Elasticsearch as the search engine. The work is based on functional, data and performance requirements set by TaxiCaller.The evaluation has shown that most of the requirements set for this work are achieved with the implemented open source geocoding service solution. Examples of these requirements are correctness of the search results and that the address, street, venue or intersection in the search results should be fully specified.The functional requirement to convert an intersection to coordinates is not achieved when the intersection can not be uniquely identified. The performance requirement to search for a venue is not. Also, the data requirement that the postal code in the search results should be fully specified is not achieved.Sometimes but not always a licensed map-service can provide better data. 目前市场上有许多地图提供商。任何希望在应用程序中使用许可地图服务的人都必须支付许可费。这笔费用可能会成为一笔巨大的费用，并影响最终客户必须支付的价格。本文研究了如何建立和改进开源地理编码服务，以便对许可的地图服务进行测量。地理编码是具有输入地址并返回由纬度和经度坐标组成的位置的技术。调查是通过实施开源解决方案作为概念证明来完成的，其目的是回答开发开源地理编码服务的可行程度，以及与许可地图服务一样快速准确和完整的问题。开源解决方案是与TaxiCaller Nordic AB合作开发的。在实现中，Pelias项目已被用作地理编码器以及来自OpenStreetMap和Who's On First以及Elasticsearch数据集的地图数据作为搜索引擎。这项工作基于TaxiCaller设定的功能，数据和性能要求。评估表明，通过实施的开源地理编码服务解决方案，可以实现为此项工作设置的大部分要求。这些要求的示例是搜索结果的正确性，并且应完全指定搜索结果中的地址，街道，地点或交叉点。当无法唯一地识别交叉点时，不能实现将交叉点转换为坐标的功能要求。搜索场地的性能要求不是。此外，未实现搜索结果中的邮政编码应完全指定的数据要求。有时但并非总是获得许可的地图服务可以提供更好的数据。

Approximation Algorithms in Allocation, Scheduling and Pricing

Scipedia content — Tue, 26 Jan 2021 17:32:39 +0100

This dissertation examines four optimisation problems. The first chapter examines the optimisation of network usage to prevent traffic congestion and internet data issues. The second chapter describes cyclical production planning for machines, such as those used to process huge volumes of lycra. In the third chapter, tasks that involve several components (such as processing time and memory use) are planned on computers so that no single computer is overloaded. The fourth chapter describes strategies for hiring highly skilled employees and strategies to increase the profit margins of a product. A theoretical lower limit is defined for the complexity of each problem and an algorithm is developed to approach this lower limit.

A new business model strategy to improve shared mobility services : A case study on Sweden

Scipedia content — Tue, 26 Jan 2021 17:31:48 +0100

It is widely recognized that the world’s over-reliance on transportation contributes to many environmental problems, especially in urban areas. Sustainable mobility is a solution and an important dimension of a Smart City. Shared mobility services are part of sustainable mobility and they are widening its portfolio especially in the past decade. However, the number of users is still low compared to its high potential, and innovative solutions can only succeed with the combination of increasing the awareness of citizens, incentivizing them, and promoting their behavioural change. This paper is dedicated to the shared mobility business models as part of the collaborative consumption, and finding out the challenges and opportunities of this emerging market in a Swedish context and comparing it to a Moroccan one. The goal is to explore the key features of the main market players and the possible ways of improvements that could possibly take carpooling and car-sharing to a next level. It explores the high potential of gamification and other mechanisms to incentivize voluntary behavioural changes towards shared mobility solutions. In a first place the theoretical part provide an overview of the shared mobility in general with its different aspects highlighting the role of new technologies and internet in the development of this concept. An online survey aimed at testing the knowledge of the respondents on the concept, discover which elements affect their involvement and find out how things can be improved by analysing the feedbacks. Det är allmänt känt att världens beroenden av transporter bidrar till många miljöproblem, särskilt i stadsområden. Hållbar mobilitet är en lösning och en viktig dimension i en smart stad. Delade mobilitetstjänster är en del av hållbar mobilitet och dess portfölj har utökats särskilt under det senaste decenniet. Antalet användare är dock fortfarande lågt jämfört med den höga potentialen och innovativa lösningar kan bara lyckas med kombinationen av att öka medvetenheten om medborgarna, stimulera dem och främja deras beteendeförändringar. Denna rapport är inriktat på affärsmodellerna för delad mobilitet som en del av konsumtion genom samarbete och identifierar utmaningarna och möjligheterna på den nya marknaden i ett svenskt sammanhang och jämför det med en marockansk. Målet är att utforska huvudaktörerna hos de viktigaste marknadsaktörerna och möjliga sätt för förbättringar som möjligen kan ta bilpoolning och bildelning till nästa nivå. Potentialen inom gamification och andra mekanismer för att stimulera frivilliga beteendemässiga förändringar mot gemensamma mobila lösningar undersöks. Inledningsvis ger den teoretiska delen en översikt över den delade mobiliteten i allmänhet med sina olika aspekter som framhäver rollen som ny teknik och internet vid utvecklingen av detta koncept. Genom en online-undersökning som syftar till att testa kunskapen om konceptet hos de svarande, har faktorer som påverkar deras engagemang och hur saker kan förbättras identifierats.

Database system design and implementation for Marine air-traffic-controller training

Scipedia content — Tue, 26 Jan 2021 17:28:29 +0100

This project focused on the design, development, and implementation of a centralized electronic database for air-traffic-controller (ATC) training within the Marine Corps. The Marine Corps currently has individual electronic training database-management systems at the unit level. The existing training database-management systems are client based, unstandardized, and have significant data-entry redundancy. We developed a centralized system that is scalable and capable of supporting detailed training statistics. We identified several critical features required for successful implementation and developed a system capable of importing and processing existing training data. We analyzed an existing training database-management system used at the unit level and developed methods for accurately exporting the existing system's stored generic data. We processed the raw data and properly migrated the data to a prototype database-management system, which involved processing for proper data integrity, database normalization, and enforcing unique record-identifier usage. We developed a front-end graphical user interface to interact with the developed system and the stored training data. Future system improvements include migration to a military network, adaptation by additional units, and full integration with the Navy's Visual Information Display System. http://archive.org/details/databasesystemde1094555649 Captain, United States Marine Corps Approved for public release; distribution is unlimited.

Analysis of global marine environmental pollution and prevention and control of marine pollution : Proposal of sollutions

Scipedia content — Tue, 26 Jan 2021 17:26:07 +0100

The ocean, the origin of life, the total area of about 360 million square kilometers, accounting for 71% of the Earth\\'s surface area. Ocean Freight has become the world\\'s most important import and export trade mode of transport. Our daily life is also closely linked with the ocean, the ocean food, marine-related products. It can be said that the ocean has become the most important part of people\\'s life around the world. However, the current situation of marine environment is not optimistic, marine pollution has become a very important topic in today\\'s society. The oil spill incident; the oil Leakage incident; or the chemical incident. All of these marine pollution incidents have caused significant and difficult recovery of the marine environment. So, how do we prevent and control the occurrence of these marine pollutions? How to restore and manage contaminated waters? This article we will focus on several major marine pollution incidents in the history of the world to discuss and analyze the pollution of the world\\'s oceans, how to prevent and control marine pollution, and how to treat the polluted oceans.

Functional requirements for sustainable short sea logistics system: Ports’ perspective

Scipedia content — Tue, 26 Jan 2021 17:20:25 +0100

Purpose: The purpose of the thesis is to define functional requirements for sustainable short sea logistics system from ports’ perspective. Research methodology: In this study, a qualitative research methodology is applied. Semi-structured interviews were conducted to collect data from various port representatives. Systemic approach was employed. The collected data was analyzed by using systems engineering method – requirements analysis. Results: Analysis shows that port representatives have quite similar attitudes towards sustainability in short sea shipping and see the role of ports as a vital element in multimodal transportation system. Main requirements for sustainable short sea logistics system, as were derived, are: centralized port network ownership, single digital platform for communication between parties, advanced telematics and control systems for cargo handling and infrastructure development in and outside the ports. Contribution: This study contributes to the knowledge creation on sustainability in short sea logistics from ports’ perspective.

Non-Intrusive Cell Load Estimation in Commercial LTE Networks for Media Selection in Hybrid V2X Systems

Scipedia content — Tue, 26 Jan 2021 17:17:07 +0100

With the advent of intelligent transportation systems and their associated more stringent requirements in terms of latency and packet delivery ratio, existing radio access technologies have exhibited a limited performance in specific scenarios that makes their sole operation in isolation unreliable for safety-related applications. In this context, hybrid V2X systems represent the state-of-the-art approach to address such challenge. Under this paradigm, the efficient operation of the system relies on a media selection algorithm, which uses different network parameters for predicting the technology that is foreseen to perform the best in a given scenario. While the network load is here regarded to affect the latency of the communication, no quantitative study has been found in the literature which supports this claim. Furthermore, the inaccessibility to this metric for commercially available off-the-shelf user equipments prevents a straightforward analysis of such parameter and its effects on C-V2X communications. In order to fill that gap, a framework has been designed and implemented over the course of this thesis that non-intrusively gathers information from live LTE networks when traversing them using an ITS-enabled vehicle. Such information has been then post-processed and used to perform a mapping of the deployed frequency bands in both rural and urban environments, as well as for evaluating principally the relationship between the latency experienced in on-road LTE communications with the instantaneous uplink load estimated for the serving eNodeBs traversed in an urban environment, without any assistance of the network. Thus, the overall uplink load has been estimated and in-depth analysis on the load per eNodeB has been carried out; during the tests, however, the uplink load has been estimated to be below 30% for the scenario under analysis and no straightforward correlation with the latency experienced when transmitting messages with different sizes has been identified, which suggests that further measurements need to be taken. On the other side, it was found that the radio resource allocation scheme used for uplink grant assignments by the eNodeBs under analysis is exploitable for reducing the cell load estimation time, which will support the migration of the set-up towards a real-time realization. The developed system therefore constitutes the groundwork for later analysis that will allow a more straightforward characterization of this relationship in different scenarios, which will ultimately serve to improve the media selection algorithm in hybrid V2X networks.

Application of Blockchain Technology for the Charging Infrastructure of Electric Vehicles - Technical, Environmental, Economic, Legal and Social Aspects

Scipedia content — Tue, 26 Jan 2021 17:14:43 +0100

von Siegbert Zöhrer Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprueft Technische Universität Wien, Masterarbeit, 2018

Battery Life Optimal Operation of Electric Vehicles

Scipedia content — Tue, 26 Jan 2021 17:14:05 +0100

Optimization of Feedstock Blends to Improve Biodiesel Cost Effectiveness and Manage Environmental Impacts

Scipedia content — Tue, 26 Jan 2021 17:09:46 +0100

Tese de doutoramento em Sistemas Sustentáveis de Energia, apresentada ao Departamento de Engenharia Mecânica da Faculdade de Ciências e Tecnologia da Universidade de Coimbra The controversy raised around biofuels sustainability increased the pressure on biodiesel producers to be as cost efficient as possible and, simultaneously, ensure the sustainability of the biodiesel. As about 85% of biodiesel production costs are attributed to feedstock cost and each feedstock has a different environmental profile, operational level decision making about feedstock selection is crucial to reduce production costs and manage biodiesel environmental performance. This thesis explores opportunities to improve biodiesel cost effectiveness at the operational level, particularly in the feedstock selection process, by assessing the use of waste-based feedstocks (Waste Cooking Oil, WCO) in blends with conventional feedstocks (palm, rapeseed and soya) and hedging feedstock purchase, whilst managing environmental impacts. For this purpose, an uncertainty-aware decision aiding tool to assess economic and environmental tradeoffs of decisions at the operational level, addressing feedstock compositional and price uncertainty, was developed. The model combines environmental life-cycle assessment (LCA) with blending models using multi-objective optimization to assess water scarcity (WSI), water degradability – acidification (AA), eutrophication (EU), ecotoxicity (FT) and human toxicity (HT) – and Greenhouse Gas (GHG) emissions (CC). Data from different crop cultivation locations were considered: Colombia and Malaysia for palm; Argentina, Brazil and the United States (US) for soybean; and, Germany, France, Spain, Canada and the US for rapeseed. An approach was developed to facilitate the decision process that enables the decision-maker to select the best compromise feedstock blend based on an explicit overall environmental performance. Results show that incorporating feedstocks’ compositional uncertainty allows the use of WCO in blends with conventional feedstocks without compromising biodiesel technical performance. A reduction of total feedstock cost was obtained for blends with WCO relatively to equivalent (similar technical performance) blends composed only of virgin oils. The percentage of cost reduction depends on the relation among the prices of the feedstocks. Moreover, the use of WCO in the blends allows a reduction in cost variation reduction relatively to virgin oils blends because the price of that feedstock presents lower volatility comparatively to the conventional feedstocks. The differences observed in the environmental assessment of the various virgin oils systems are mainly related to water scarcity of the location, and the fertilization and pesticides schemes used in each crop/location. Results show that higher water scarcity footprint are due to both high water consumption and high water scarcity of the cultivation site. For the toxicity categories (HT and FT), the highest values are ascribed to the high quantity of pesticide used in the cultivation, while for CC, AA and EU the main contributor is the quantity of fertilizers. WCO presents the lowest values WSI, CC, EU and AA. The multi-objective analysis showed that lower CC and WSI solutions (blends) can be obtained at a lower cost if WCO is included in the biodiesel blend. The same conclusion is obtained when more environmental objectives (AA, EU, FT and HT) are considered in the analysis. The decision-aiding approach developed allows for the visualization of the tradeoff between cost and environmental impacts, facilitating the decision process when more than three objectives are at stake. This research shows that the inclusion of WCO in a diversified portfolio of feedstocks used in blending optimization models is an attractive approach to improve biodiesel cost effectiveness and environmental performance. The model developed can be further used to optimize the blending of alternative feedstocks and to assess the technical viability of other waste-based feedstock (e.g. animal fat) or emerging feedstocks such as algae. Although the tool was designed specifically for biodiesel production system, it can be adapted to other industries, particularly in the recycling sector, to support production planning at the operational level to enhance technical, economic and environmental performance of these industries. A controvérsia gerada em torno da sustentabilidade dos biocombustíveis aumentou a pressão nos produtores de biodiesel para serem o mais eficientes possível em termos de custos e, simultaneamente, garantirem a sustentabilidade do biodiesel. Como cerca de 85% do custo total de produção é atribuído ao custo da matéria-prima, e cada uma apresenta um perfil ambiental diferente, decisões ao nível operacional acerca de selecção de matéria-prima são cruciais para melhorar a performance económica e ambiental do biodiesel. Esta tese explora estratégias para reduzir custos de produção de biodiesel, particularmente no processo de selecção de matérias-primas, ao avaliar o uso de resíduos (Óleo Alimentar Usado, OAU) em misturas com óleos convencionais (soja, palma, colza) e planear a compra de matéria-prima, e, simultaneamente, gerir os impactes ambientais. Para tal, foi desenvolvida uma ferramenta de apoio à decisão para avaliar compromissos económicos e ambientais de decisões efectuadas ao nível operacional. Esta ferramenta tem em conta a incerteza associada à composição e ao preço da matéria-prima. O modelo desenvolvido combina Avaliação de Ciclo de Vida (ACV) ambiental com algoritmos de mistura através de optimização multiobjectivo para avaliar a escassez de água (WSI), degradabilidade da água – acidificação (AA), eutrofização (EU), ecotoxicidade (FT) e toxicidade humana (HT) – e, emissões de gases com efeito de estufa (CC). Diferentes locais de cultivo foram considerados: palma cultivada na Colômbia e Malásia; soja na Argentina, Brasil e Estados Unidos; e colza na Alemanha, França, Espanha, Canadá e Estados Unidos. Foi desenvolvida uma abordagem para facilitar o processo de decisão que permite ao decisor escolher a mistura com base na performance ambiental global. Os resultados mostram que é possível utilizar OAU em misturas com óleos virgens sem comprometer a qualidade do biodiesel se a incerteza composicional dos óleos for tida em conta. Estas misturas apresentam menores custos relativamente a misturas de óleos virgens. A percentagem de redução depende da relação entre os preços dos diferentes óleos. Adicionalmente, o uso de OAU nas misturas permite obter também uma redução na variação dos custos de produção porque o preço desta matéria-prima apresenta menor volatilidade relativamente à observada nos óleos convencionais. As diferenças observadas na avaliação ambiental dos diferentes óleos virgens estão relacionadas com a escassez de água da região e o esquema de fertilização/pesticidas usados em cada cultura/local. Os resultados mostram que pegadas hídricas mais elevadas devem-se simultaneamente a maiores consumos de água e elevada escassez dos locais de cultivo. Para as categorias de toxicidade (HT e FT), os valores mais elevados são devido à elevada quantidade de pesticidas utilizados no cultivo, enquanto que para CC, AA e EU a maior contribuição provém da quantidade de fertilizantes. WCO apresenta os menores valores para WSI, CC, EU e AA. Na análise multiobjectivo realizada, observou-se que soluções (misturas) com valores de CC e WSI mais baixos podem ser obtidos com menor custo se OAU for incluído nas misturas. A mesma conclusão é obtida quando mais objectivos ambientais (AA, EU, FT e HT) são considerados na análise. A ferramenta de apoio à decisão desenvolvida facilita o processo de decisão ao permitir a visualização do compromisso entre o objectivo económico e os ambientais quando mais do que três objectivos são considerados. Nesta investigação é evidenciado que a inclusão de OAU num portfólio diversificado de matérias-primas usado em modelos de optimização de misturas é uma abordagem atractiva para melhorar a performance económica e ambiental do biodiesel. O modelo desenvolvido pode ser utilizado para optimizar a mistura de matérias-primas alternativas e avaliar a viabilidade técnica de utilizar outros resíduos (por ex. gorduras animais) nas misturas. Embora a ferramenta tenha sido desenvolvida especificamente para produção de biodiesel, pode ser aplicada a outras indústrias, nomeadamente de reciclagem, para apoio à decisão no planeamento de produção com vista a melhorar a performance técnica, económica e ambiental dessas indústrias. Project EMSURE (Energy and Mobility for Sustainable Regions, CENTRO 07 0224 FEDER 002004) FEDER/FCT | PTDC/AGR-FOR/1510/2014 (POCI-01-0145-FEDER-016764) - SUSTAINFOR: Sustainability assessment of forest sector management strategies in the context of a bioeconomy FEDER/FCT | PTDC/AAG-MAA/6234/2014 (POCI-01-0145-FEDER-016765) - SABIOS: Sustainability assessment of bioenergy systems: a life-cycle multi-criteria decision-support approach, including land use change

Human-Technology Interactions - Understanding Design and Use Beyond Technology In Shipping

Scipedia content — Tue, 26 Jan 2021 17:08:23 +0100

The rapid advance of technologies is revolutionizing the way people work and transforming society into a digital world. In the shipping domain, many innovative technical systems have been designed and developed in the past decades, aiming to enable the maritime users to achieve the goal of safety, efficiency and effectiveness. The introduction of advanced technologies into workplaces that are intended to aid humans have also created unprecedented challenges. As their workplaces are inundated with new artefacts that cause confusion and information overloading, human users frequently find themselves in a supporting role to serve technology, being responsible for automation issues and blamed for “human errors” that sometimes result in tragic results. Today’s work in shipping is generally getting more distributed, complex and demanding. These challenges are closely associated with the design and use of technologies. Human-technology interactions in the context of sociotechnical systems has become an important research topic. It explores the relation between humans and machines to illustrate how interface design could address the human limitations, shape social interactions and provide ecological implications. This thesis considers the context of the shipping domain to investigate the impact of innovative technology, design issues and opportunities in various projects that attempt to increase safety or/and efficiency. The exploration and discourse in these applied projects are positioned in sociotechnical systems which include human, technology and organisational constituents. The thesis aims to achieve a deeper understanding of human-technology interactions from psychological, sociological and ecological perspectives, reflecting the ways in which technology interacts with humans. It aims to form a pluralistic epistemology to provide design implications and enlighten knowledge and organisational management within sociotechnical systems. The results have identified many issues related to situation awareness, attention and automation bias. It suggests the importance of adapting interfaces to the human limitations and accommodating the context change to support decision making. Perspectives of Activity Theory, distributed cognition and situated learning have high reference value in human-computer interaction research, providing insightful understanding about the nature of knowledge and interaction design, particularly how tool mediation could facilitate social interaction. In addition, technology-centric design that only concerns “user-interface” interaction is identified having significant limitations in complex systems. “Human errors” and organisational failures should be perceived via a holistic thinking. The results have presented the importance of adopting pluralistic approaches to understand the sociological factors and the nature of the work that is undergoing transitions along the shipping industry’s ecology. Overall, the thesis has identified the need to go beyond the pure cognitivist approach to better understand the complexity of human-computer interaction and human factors research, forming a deepened understanding towards an emerging interdisciplinary language of sociotechnical systems. To truly contribute to safety, efficiency, effectiveness and sustainability, it is critical to develop a pluralistic epistemology and a comprehensive human-centric vision regarding design and technological innovation in the digital revolution.

Control jerárquico para redes de tráfico urbano

Scipedia content — Tue, 26 Jan 2021 17:05:00 +0100

Las redes de tráfico urbano en las grandes ciudades están siendo ocupadas por una alta demanda de vehículos. Como resultado de este fenómeno, la contaminación, el tiempo total de viaje y el estrés se incrementan considerablemente. Actualmente, los problemas de congestión se investigan a partir de diferentes enfoques, uno de ellos es el modelado dinámico del tráfico vehicular, el cual es un elemento de diseño no para el monitoreo y control de tráfico a través de la gestión de la red semafórica. El modo de operación de los semáforos incide directamente en los índices de desempeñe no de movilidad. Por lo tanto, en la tesis se propusieron tres arquitecturas de control actuado de semáforos, es decir que ajustan sus variables según los volúmenes de tráfico de las vías. Una de estas estrategias es una combinación de sistemas de control cl ́asico con sistemas de control ́optimo organizados en una arquitectura jerárquica, que permitió escalar la coordinación de corredores a escenarios de una escala mayor, teniendo en cuenta las interacciones entre los subsistemas definidos. La metodología para la implementación y posterior validación de los m ́métodos propuestos consistió o en la integración del microfilmador de tráfico SUMO y el entorno de simulación Matlab a través de la interfaz Traci4Matlab, lo que permitió implementar las estrategias en un corredor de 5 intersecciones de la ciudad de Medellín. Los resultados obtenidos reflejaron una mejora entre el 36 % y 63 % de los modos de operación actuados respeto al tiempo fijo. Abstract; Urban traffic networks in big cities are being increasingly occupied by vehicles. As a result of this phenomenon, pollution, time spent by drivers and stress are increased considerably. Currently, congestion problems are investigated from different approaches. One of them is the dynamic modeling of vehicular traffic, which is a major factor in the monitoring and control through traffic light management. The mode of operation of traffic lights directly affects mobility performance index. Therefore in the thesis three traffic control architectures were proposed, they adjust their variables according to the traffic volumes. One of the strategies is a combination of classical control systems with optimal control systems, organized in a hierarchical architecture, which allowed to scale the coordination of corridors a ladder of a larger scale. The methodology for the implementation and validation of the proposed methods consisted of the integration of the SUMO traffic and Matlab through Traci4Matlab interface, which allowed the implementation of the strategies in a corridor of the city Of Medell ́ın. The results obtained describe an improvement between 36 % and 63 % of the modes of operation acted in relation to the fixed time. Real time implem entation is the most viii remarkable advantage, which motivates the use of the linear control

Understanding temporal, weather and spatialvariation patterns in São Paulo urban bus travel speeds.

Scipedia content — Tue, 26 Jan 2021 17:03:27 +0100

ualmente existem muitas fontes de dados oriundos de movimentação de pessoas e veículos. Deduzir o comportamento do tráfego a partir desses dados pode ser de grande utilidade para a gestão do tráfego. Entretanto, os métodos existentes podem não abordar todas as dimensões referentes ao comportamento do tráfego, em especial sob efeito de adversidades, como por exemplo - eventos climáticos. O objetivo dessa dissertação é apresentar uma combinação de métodos estatísticos e de análise espacial, para uso na compreensão dos padrões temporais e espaciais de variabilidade das velocidades, em condições normais e sob o impacto da precipitação. O método consiste na mineração de dados de micro trechos de deslocamento (microviagens), através da combinação de estatísticas descritivas, árvores de regressão CHAID (Chi square automatic interaction detection) e análises espaciais (Krigagem). Para a validação do método foram utilizados dados obtidos, durante março de 2014, de operação da frota de ônibus municipal da cidade de São Paulo, fornecidos pela São Paulo Transportes (SPTrans). Os dados de precipitação de chuva foram fornecidos pelo Instituto Nacional de Meteorologia (INMET). Os resultados demonstraram o impacto da precipitação sobre a variabilidade das velocidades por dia da semana e hora do dia. Adicionalmente, com base nos conjuntos de dados classificados via CHAID, foram produzidas representações da distribuição das velocidades sobre a superfície através uso da Krigagem. Observou-se uma consistente queda das velocidades no período vespertino, principalmente entre 16:00 e 19:00 horas, frequentemente agravados pela presença de precipitação. Foram selecionados casos de alta variabilidade, a partir da técnica CHAID, que foram analisados espacialmente. Os efeitos da queda da variabilidade foram observados geograficamente, demonstrando que a infraestrutura de transporte é um importante fator em sua caracterização. O estudo demonstra a viabilidade desta abordagem e a importância de incorporar a geografia no entendimento da variabilidade das velocidades em geral. Nowadays there is a wide number of movement data sources which can be useful in transportation management. However, the existing methods may not cover all traffic dimensions, especially under inclement weather. The objective of this work is presenting a combination of statistical and spatial methods which allows to understand space and time speed patterns, considering regular operation conditions in comparison with rainfall events. The method consists in sequential bus tracking data segments (micro travel) mining by the combination of descriptive statistics, CHAID (Chi square automatic interaction detection) regression trees and spatial analysis (Kriging). To validate the method, São Paulo bus fleet tracking data provided by SPTrans, and rainfall precipitation, provided by INMET was combined and processed. The results presented rainfall as a relevant factor of speed variability by day of week and time of the day. A consistent speed decrease in the afternoon period, mainly between 4:00 PM and 7:00 PM, was observed. Such effects are more intense in face of rainfall precipitation. The highest variability cases obtained by CHAID classification was selected and spatially analyzed showing the transportation infrastructure is an important variability component. Such results show the importance of a geographic approach over speed variability.

Evaluation of External Coating Performance on Buried Pipelines in the Oil and Gas Industry

Scipedia content — Tue, 26 Jan 2021 16:56:06 +0100

Automatic drone demand generation and evaluation

Scipedia content — Tue, 26 Jan 2021 16:50:56 +0100

This project consists in building a drone traffic generator capable of spawning random operations in a country. This document provides the guidelines to generate the operations taking into account the existing regulation, the forbidden flight zones, the number of operators and the concept of operations. Using the input parameters, the generator creates and assigns a fleet of drones to each operator introduced. Then, the generator spawns the operations and assigns them to drones, so that each operator has a fleet of drones and list of operations to perform. Furthermore, the operations have an assigned flight schedule to follow the typical workday of the country. The generator also allows visualizing the operations along the day by using the program Google Earth. Moreover, the conflicts and busy areas can also be seen with this program, so that the user can see where they occur. On the other hand, the generated operations are stored in two types of file. The first type corresponds to the XML files, which store the whole information relative to the operators, their fleet of drones and the operations performed by each one. The second type of file corresponds to the MavLink files. These files store the flight plans of all the generated operations. By using the simulator ArduPilot and the software Software in the Loop, the operations can be simulated to obtain the logs. These logs can be used to evaluate, for example, the implementation of ADS-B in drones. Finally, the generator allows changing the parametrization of routes in each simulation, as well as the number of operators and the drone models. Hence, the user is able to see the evolution of drone traffic with the generations. Moreover, the generator allows downloading CSV and XML files, where all the information relative to the generated operations, the assigned fleet of drones and the operators is collected.

Modélisation 3D de la résistance à l’avancement en milieu conﬁné et application à un éco-pilote ﬂuvial

Scipedia content — Tue, 26 Jan 2021 16:44:50 +0100

n eco-driving prototype, named EcoNav, is developed with the aim of optimizing a vessel speed in order to reduce fuel consumption for a given itinerary. EcoNav is organized in several modules : - a 2D hydraulic model simulating the flow conditions (current speed and water depth) along the itinerary; - a ship resistance model calculating the thrust necessary to counteract the hydrodynamic forces ; - a fuel consumption model calculating the fuel consumption corresponding to the thrust input; - a non linear optimization algorithm calculating the optimal speed profile. In order to evaluate the fuel consumption of an inland vessel, a ship resistance numerical model is developed in the first part of this PhD. This 3D numerical model simulates the flow around an inland self-propelled vessel and evaluates the hydrodynamic forces acting on the hull. A RANS solver is coupled with a quasi-Newton approach to find the equilibrium position and calculate ship sinkage. This method is validated by comparing the results of numerical simulations to towing tank tests. The numerical results with and without sinkage are also compared to study the influence of sinkage on ship resistance and on the accuracy of the method. Additionally, some empirical models are investigated and compared with the accuracy of the numerical method. Finally, the numerical model is used to determine if channel with and water depth restriction contribute to the same amount of ship resistance increase for the same level of restriction. The results of that investigation give insight to whether channel restriction can be characterized by a unique parameter (for instance the blockage ratio) or two parameters to distinguish water depth and channel with effects. In the second part of this PhD, the numerical methods used in the speed optimization model are described and validated. The speed optimization model is then used to simulate a real case: the itinerary of the self-propelled ship Oural on river Seine, between Chatou and Poses (153 km). The optimized fuel consumption is compared with the non-optimized fuel consumption, based on AIS speed profile retrieved on this itinerary. The effects of the ship trajectory and travel duration on fuel consumption are also investigated. The results of those investigations showed that optimizing the ship speed lead to an average fuel saving of 8 % and that using an optimal track and including real time information such as lock availability and river traffic can lead to additional fuel savings.; Les travaux de cette thèse ont pour but de développer un prototype d’éco-pilote, nommé EcoNav, permettant d’optimiser la vitesse d’un bateau afin de réduire sa consommation de carburant. EcoNav est composé de plusieurs modules dont : un modèle hydraulique 2D simulant l’écoulement hydrodynamique (vitesse du courant et hauteur d’eau) le long du trajet du bateau; - un modèle de résistance à l’avancement servant à alimenter un modèle de prédiction de la consommation de carburant; - un algorithme d’optimisation permettant de trouver le profil optimal de vitesse. Afin de pouvoir estimer la consommation de carburant, un modèle numérique de la résistance à l’avancement en milieu confiné a été développé durant la première partie de cette thèse. Ce modèle numérique 3D simule l’écoulement du fluide autour du bateau et permet de calculer les forces agissant sur sa coque. La résolution des équations RANS est couplée avec un algorithme de quasi-Newton afin de trouver la position d’équilibre du bateau et calculer son enfoncement. Cette méthode est validée en comparant les résultats numériques avec des résultats expérimentaux issus d’essais en bassin de traction. L’influence de l’enfoncement sur la résistance à l’avancement et la précision de la méthode est étudiée en comparant les résultats numériques obtenus avec et sans enfoncement. La précision des modèles empiriques de prédiction de la résistance à l’avancement est également comparée à celle du modèle numérique. Enfin, le modèle numérique est utilisé afin de déterminer si le confinement en largeur ou en profondeur ont une influence identique sur l’augmentation de résistance à l’avancement. Les résultats de cette étude permettent d’établir si le confinement de la voie d’eau peut être caractérisé à l’aide d’un paramètre unique (coefficient de blocage par exemple) ou bien deux paramètres permettant de distinguer le confinement latéral et vertical. Dans la seconde partie de cette thèse, les méthodes numériques utilisées pour le modèle d’éco-pilote sont décrites et comparées afin de sélectionner celles qui sont le plus adaptées à chaque module. EcoNav est ensuite utilisé afin de modéliser un cas réel : celui du bateau automoteur Oural navigant sur la Seine entre Chatou et Poses (153 km). La consommation optimisée est comparée à la consommation non optimisée, calculée à partir des vitesses AIS observées sur le tronçon étudié. L’influence de la trajectoire du bateau et de son temps de parcours sur sa consommation sont également étudiés. Les résultats de ces investigations ont montré qu’optimiser la vitesse du bateau permet d’obtenir une réduction de la consommation de carburant de l’ordre de 8 % et qu’optimiser la trajectoire du bateau ainsi que prendre en compte des informations en temps réel (disponibilité des écluses, trafic sur le fleuve) peuvent permettre de réaliser des économies de carburant supplémentaires.

Strategic Conformance: Exploring Acceptance of Individual-Sensitive Automation for Air Traffic Control

Scipedia content — Tue, 26 Jan 2021 16:42:46 +0100

LIKE many complex and time-critical domains, air traffic control (ATC) is facing a fundamental modernization that builds on the use of more advanced automation (represented by SESAR in Europe and NextGen in the United States). The current function allocation-based relationship between controller and machine is envisioned to evolve to a more fluid, continuous and mutually coordinated team relationship. Consequently, the controller is expected to assume a supervisory and monitoring role, while relinquishing much of the tactical “hands-on” tasks to automation. ATC automation, in turn, is expected to grow in intelligence and its cognitive abilities to become more of a team member providing decision support and acting more autonomously. In association to these changes, one of the most pressing human factors challenges is how we can design automation that is embraced, accepted and trusted by the controller...

Design of the model of an electric supercar

Scipedia content — Tue, 26 Jan 2021 16:34:20 +0100

Outgoing

An Approach to Mitigate Electric Vehicle Penetration Challenges through Demand Response, Solar Photovoltaics and Energy Storage Applications in Commercial Buildings

Scipedia content — Tue, 26 Jan 2021 16:28:57 +0100

Electric Vehicles (EVs) are active loads as they increase the demand for electricity and introduce several challenges to electrical distribution feeders during charging. Demand Response (DR) or performing load control in commercial buildings along with the deployment of solar photovoltaic (PV) and ice storage systems at the building level can improve the efficiency of electricity grids and mitigate expensive peak demand/energy charges for buildings. This research aims to provide such a solution to make EV penetration transparent to the grid. Firstly, this research contributes to the development of an integrated control of major loads, i.e., Heating Ventilation and Air Conditioning (HVAC), lighting and plug loads while maintaining occupant environmental preferences in small- and medium-sized commercial buildings which are an untapped DR resource. Secondly, this research contributes to improvement in functionalities of EnergyPlus by incorporating a 1-minute resolution data set at the individual plug load level. The research evaluates total building power consumption performance taking into account interactions among lighting, plug load, HVAC and control systems in a realistic manner. Third, this research presents a model to study integrated control of PV and ice storage on improving building operation in demand responsive buildings. The research presents the impact of deploying various combinations of PV and ice storage to generate additional benefits, including clean energy generation from PV and valley filling from ice storage, in commercial buildings. Fourth, this research presents a coordinated load control strategy, among participating commercial buildings in a distribution feeder to optimally control buildings' major loads without sacrificing occupant comfort and ice storage discharge, along with strategically deployed PV to absorb EV penetration. Demand responsive commercial building load profiles and field recorded EV charging profiles have been added to a real world distribution circuit to analyze the effects of EV penetration, together with real-world PV output profiles. Instead of focusing on individual building's economic benefits, the developed approach considers both technical and economic benefits of the whole distribution feeder, including maintaining distribution-level load factor within acceptable ranges and reducing feeder losses. Ph. D.

Framework for traffic engineering on software defined networks using network calculus.

Scipedia content — Tue, 26 Jan 2021 16:25:18 +0100

demanda de eficiência no gerenciamento das redes aumenta atualmente devido ao rápido desenvolvimento da computação em nuvem e a implantação em grande escala de centros de dados. O controle da infraestrutura deve ser capaz de classificar os diversos tipos de tráfego para aplicações diferentes, e prover o atendimento adequado no menor tempo possível. Porém, devido ao dinamismo da rede, nem sempre podem ser garantidos os requisitos mínimos necessários na Internet. Os mecanismos propostos para a engenharia de tráfego até hoje, são baseados em arquiteturas inflexíveis com a camada de controle e dados fortemente integrados. Isto dificulta um atendimento diferenciado adaptável aos diversos padrões de tráfego das aplicações modernas. Para enfrentar os problemas de flexibilidade das redes tradicionais, as Redes Definidas por Software, apresentam um paradigma inovador que separa as camadas de controle e encaminhamento de pacotes de forma a garantir a utilização eficiente dos recursos disponíveis, e ao mesmo tempo maior flexibilidade de implementação. Este paradigma permite conhecer o estado da rede e a sua topologia em tempo real, o que faz possível a reconfiguração de rotas e alocação de recursos de forma dinâmica. Esta dissertação apresenta um framework para engenharia de tráfego em SDN que utiliza a teoria matemática Network Calculus como ferramenta para subsidiar a caracterização e o policiamento de fluxos de pacotes. Através desta teoria, as decisões de encaminhamento e a distribuição do tráfego são baseadas não só por valores obtidos monitorando a rede, como também por projeções determinísticas que descrevem o comportamento do tráfego. Os resultados obtidos nos experimentos, comprovaram a eficiência no balanceamento de carga da rede em termos de atraso, demonstrando ganhos em termos de vazão do sistema e possibilitando a diminuição da porcentagem de perda de pacotes dos fluxos trafegados. O framework proposto visa contribuir na solução dos desafios relacionados a se estabelecer Engenharia de Tráfego para SDN com a especificação de mecanismos de gerenciamento adaptáveis as mudanças topológicas da rede, as diferentes características dos fluxos e que sejam capazes de distribuir de forma equilibrada o tráfego na rede. The demand for network management efficiency is currently boosted by the rapid development of cloud computing and the large-scale deployment of data centers. Infrastructure control should be able to classify the various types of traffic for different applications, and provide adequate service in the shortest time possible. However, due to the dynamism of the network, the necessary minimum requirements on the Internet can not always be guaranteed. The proposed mechanisms for traffic engineering to date are based on inflexible architectures with the control and data layer strongly integrated. This hinders a differentiated service adaptable to the different traffic patterns of modern applications. To address the flexibility problems of traditional networks, Software Defined Networks presents an innovative paradigm that separates packet control and datapath layers to ensure the ecient use of available resources while providing greater deployment flexibility. This paradigm allows to know the state of the network and its topology in real time, which makes it possible to reconfigure routes and allocate resources dynamically. This work presents a framework for SDN traffic engineering that uses the mathematical theory Network Calculus as a tool to subsidize the characterization and policing of packet flows. Through this theory, routing decisions and traffic distribution are based not only on values obtained by monitoring the network, but also on deterministic projections of traffic behavior. The results obtained in the experiments, proved the efficiency in the load balancing of the network based on flow delay, demonstrating gains in terms of total system throughput and enabling the reduction of the percentage of packet loss of the traffic flows. The framework proposed aims to contribute to the solution of the challenges related to establishing Traffic Engineering for SDN with specification of management mechanisms, adaptables to the topological changes of the network, the different characteristics of the flows and capable of distribute in a balanced way the traffic in the network.

How will increased demand for electric vehicles influence the price and production of cobalt and lithium?

Scipedia content — Tue, 26 Jan 2021 16:21:14 +0100

The demand for electric vehicles is predicted to increase drastically mainly due to climate concerns. Lithium and cobalt, two metals used in the battery for electric vehicles have therefore gained more attention as there is uncertainty regarding future availability. The prices of cobalt and lithium have risen considerably in the last two years due to increased demand for electric vehicles, hence increased demand for the metals. Thus, in this thesis we investigated how increased demand for electric vehicles will influence the price and production of cobalt and lithium. By simplifying the demand and supply functions and modelling them on reduced form, we obtain the covariation between electric vehicle sales and the metal prices. Thereafter, we discuss whether these relationships remain stable. The results of the estimations indicate that the price of cobalt and lithium will rise by 5.5 and 6.3 percent per annum, respectively, if the demand for electric vehicles rise sharply. In order to reduce the risk of running out of input factors for the electric vehicle production, it is reasonable to believe that battery and electric vehicle manufacturers will store cobalt and lithium. Thus, the demand for the metals will be higher than what the assumed growth in electric vehicle sales suggests. An inelastic supply curve, in combination with a greater shift in demand, will lead to a higher short-term price growth of both cobalt and lithium than the model predicts. Technological development in extraction, increased secondary supply from batteries, and the completion of new mines following 2022, lead to a positive shift in the supply curve and make it more elastic. Advancements in battery technology will reduce the amount of cobalt and lithium in the battery. Consequently, the impact of increased demand for electric vehicles will have less effect on the demand for the metals in the long run. Due to these dynamics in interaction, the price of cobalt and lithium will in the long term stabilize at a lower level than the observed prices in December 2017. Det er spådd en meget sterk global økning i etterspørselen etter elbiler hovedsakelig på grunn av et mål om å redusere CO2 utslipp. Litium og kobolt, to metaller som anvendes i elbilbatteriet har dermed fått økt oppmerksomhet da det er usikkerhet vedrørende fremtidig tilgjengelighet. Som følge av økt etterspørsel etter elbiler og dermed økt etterspørsel etter metallene, har prisen på kobolt og litium steget betraktelig de to siste årene. I denne masteroppgaven undersøkte vi dermed hvordan økt etterspørsel etter elbiler vil påvirke pris og produksjon av kobolt og litium. Ved å modellere forenklede etterspørsels- og tilbudsfunksjoner på redusert form, finner vi sammenhenger mellom metallprisene og elbilsalg. Deretter diskuteres det om disse relasjonene forblir stabile. Resultatene fra estimeringen viser at prisen på kobolt og litium vil stige årlig med henholdsvis 5,5 og 6,3 prosent dersom etterspørsel etter elbiler stiger kraftig. For å redusere risikoen for å gå tom for innsatsfaktorer til elbilproduksjonen, er det rimelig å anta at batteri- og elbilprodusenter vil lagre kobolt og litium. Dermed blir etterspørselen etter metallene høyere enn den antatte veksten i elbilsalg tilsier. En uelastisk tilbudskurve kombinert med større skift i etterspørselen vil føre til at den kortsiktige prisveksten på metallene blir høyere enn de modellerte prisøkningene. Teknologisk utvikling i gruvedrift, resirkulering av kobolt og litium fra elbilbatteriet og ferdigstillelse av nye gruver etter 2022, er faktorer som fører til positivt skift i tilbudskurven og gjør kurven mer elastisk. Utvikling i batteriteknologi vil redusere mengden kobolt og litium i batteriet. Dette resulterer i at økt etterspørsel etter elbiler har en mindre innvirkning på etterspørselen etter metallene. Disse dynamikkene vil i samspill føre til at prisen på kobolt og litium på sikt vil stabiliseres på et lavere nivå enn de observerte prisene i desember 2017. M-ØA

Facility location models for electric vehicle charging infrastructure

Scipedia content — Tue, 26 Jan 2021 16:12:45 +0100

This thesis deals with the study of current charging infrastructure availability in highways, as well as proposing optimal allocations for new stations. First, a Machine Learning model is trained in order to estimate the actual range of an electric vehicle. This model will be constructed using heterogeneous data sources and variables that influence the total autonomy, such as speed, temperature, degradation or elevation, among others. Second, this model is used in combination with geospatial data regarding French highway and charging infrastructure locations, in order to propose a methodology for analyzing the availability level of charging stations in highways for electric vehicles. Finally, an optimization framework is implemented to decide the opening of several charging stations inside a highway, providing as possible locations rest and service areas already built, and considering current highway operational charging points.

Obstacles for Remote Air Traffic Services: A Multilevel Perspective

Scipedia content — Tue, 26 Jan 2021 16:10:01 +0100

traffic services (ATS) play an important role for flight safety. Remote air traffic services (RATS) represent a novel, more digitalized, ATS solution. In some aspects, RATS can be argued to outperform conventional ATS. However, as it entails various sociotechnical obstacles, making RATS the dominant solution for ATS is challenging. An inadequate awareness of such sociotechnical obstacles potentially impedes the competitiveness of RATS in general and the RATS providers in particular. This study intends to - from a sociotechnical perspective - identify main obstacles as faced by RATS when aspiring to become the dominant solution for ATS. In order to identify such obstacles, an abductive case study has been conducted. Empirical data was primarily gathered by semi-structured interviews with 10 key stakeholders involved, directly or indirectly, with RATS. The study is delimited to principally gather empirics from Sweden and the United Kingdom. Theoretical concepts of Large Technical Systems (LTS) and the Multilevel Perspective (MLP) are employed to understand and analyze the empirical data. The identified obstacles faced by RATS are mapped into the different levels of the MLP. Obstacles have been identified in all levels of the MLP. The most prominent obstacles seem to lay in social aspects of change processes, a proposition-perception gap, and connectivity infrastructure dependency. Flygtrafiktjänster (ATS) spelar en viktig roll för flygsäkerhet. Fjärrstyrda flygtrafiktjänster (RATS) representerar en ny, i högre grad digitaliserad, lösning för ATS. I vissa avseenden kan RATS anses prestera bättre än konventionellt utförda flygtrafiktjänster. Vägen mot ett tillstånd där RATS är den dominerande lösningen för RATS är dock kantad av olika sociotekniska utmaningar. En otillräcklig medvetenhet om dessa utmaningar kan potentiellt minska konkurrenskraften för RATS i allmänhet och för utvecklare av RATS i synnerhet. Denna studie syftar till att, från ett sociotekniskt perspektiv, identifiera utmaningar som RATS står inför i, en situation där RATS ämnar ta steg mot att bli den dominerande lösningen för ATS. För att identifiera sådana utmaningar har en abduktiv fallstudie utförts. Empirisk data samlades huvudsakligen in genom semi-strukturerade intervjuer med 10 intressenter, direkt eller indirekt involverade, i RATS. Studien är avgränsad till att huvudsakligen samla in empirisk data från Sverige och Storbritannien. Teoretiska ramverk och begrepp beträffande Large Technical Systems (LTS) och Multilevel Perspective (MLP) används för att förstå och analysera empirisk data. De identifierade utmaningarna kopplas till de olika nivåerna i MLP. Utmaningar har identifierats i alla nivåer av MLP, och de mest framstående utmaningarna tycks ligga i sociala aspekter av förändringsprocesser, ett gap mellan proposition och perception, samt ett beroende av uppkopplingsinfrastruktur.

Strategic Conformance

Scipedia content — Tue, 26 Jan 2021 16:09:42 +0100

Shifting to low-carbon transport in ASEAN: policy development in a rapidly motorising region

Scipedia content — Tue, 26 Jan 2021 16:08:48 +0100

This thesis analyses how transport policy at different levels of governance is responding to sustainability challenges and how such policies can be strengthened, particularly for climate change mitigation in the ASEAN region. Its academic contribution comprises the application of transition studies and policy studies to low-carbon transport and sustainable development. The main conclusions are: 1) The Avoid – Shift – Improve approach needs to be expanded with Access, Lifestyle and Transition considerations in order to be an effective framework that does justice to the distributional, systemic and behavioural aspects of low-carbon transport policy; 2) The newer international climate instruments, such as NAMAs, NDCs and the GCF, show more potential than the Kyoto Protocol instruments to promote sustainable, low-carbon transport, as they are better aligned to national circumstances and better suited to address the barriers that developing country policymakers face; 3) ASEAN instruments around transport focus on policy cooperation and reflect ‘networked regionalism’. Sustainable transport has played a relatively small role in ASEAN cooperation but this role is growing, and a range of ‘soft’ measures can be used to further promote low-carbon transport in its member countries; 4) At the national level, transport policy objectives support international sustainable development and climate goals, however the instruments, mechanisms and calibrations need to be strengthened to reach those objectives. Climate change has, in a few cases, led to policy windows for modifying transport policy; 5) At the local level, Southeast Asian cities such as Bangkok and Manila increasingly recognise the potential and benefits of cycling, yet much remains to be done in policy and planning to move cycling beyond a niche activity. ________________________________________

Virtual Power Plants of Electric Vehicles in Sustainable Smart Electricity Markets

Scipedia content — Tue, 26 Jan 2021 16:00:00 +0100

The batteries of electric vehicles can be used as Virtual Power Plants to balance out frequency deviations in the electricity grid. Carsharing fleet owners have the options to charge an electric vehicle's battery, discharge an electric vehicle's battery, or keep an electric vehicle idle for potential rentals. Charging and discharging can be used to provide reliable operating reserves. We develop an analytical model that manages carsharing fleets. On the one hand, the energy in the batteries of an electric vehicle can be made available to the grid as operating reserves. On the other hand, the electric vehicle can be made available for rental, where the location within the city matters: drivers want a car to be close to their place of departure or arrival. The model can also be used by Transportation Network Companies such as Uber to preposition their vehicles conveniently in a city or optimize zonal pricing. To validate our model we develop a Discrete Event Simulation platform. We calibrate this simulation with locational information (GPS), rental, and charging transactions of 1,500 electric vehicles from the carsharing services Car2Go (Daimler) and DriveNow (BMW) over several years. We investigate the influence of the charging infrastructure density, battery technology, and rental demand for vehicles on the payoff for the carsharing operator and make an international comparison between the USA, Germany, the Netherlands, and Denmark. We show that Virtual Power Plants of electric vehicles create sustainable revenue streams for electric vehicle carsharing companies without compromising their rental business.

Service-sector Guilds and the Challenge of Liberalization: The organization of maritime-cargo handling in Barcelona, c.1760-1840

Scipedia content — Tue, 26 Jan 2021 15:59:03 +0100

[eng] This thesis examines the guilds comprising the sub-sector of maritime cargo handling in Barcelona from 1760-1840, a period defined in economic terms by the progressive advance of liberal reforms and attempts at abolishing the guilds. Guilds in the service sector were responsible for activities that were vital to economic development, yet the organization of that labor remains an under-represented subject of investigation. By studying the totality of maritime-cargo handling trades of Barcelona, the thesis aims to contribute to the relatively limited scholarship of service-sector guilds and of port labor during the artisan phase. With this aim, the thesis discusses the historiography of guild and port labor studies, passing to a description of the geographic, infrastructural and socio-spatial delineations of the port based on objective and subjective considerations. By comparing the case of Barcelona to a number of other European ports, the study highlights relationships between port types and objective needs of cargo handling with the different organizational models that developed in the sub-sector. Thereafter, the investigation examines in detail the different guilds and the socio-judicial determination of responsibilities, privileges, organizational models and internal composition. Having covered these issues, the study then focuses on the various attempts at reforming or abolishing the guilds and the respective responses of these organizations to structural economic policy changes. During the period studied, the port infrastructure remained relatively unchanged and there was no mechanization of cargo-handling activities, facilitating the focus on changes in economic policy as factors in the application of liberal measures and the organizational responses of the guilds to these important changes. As such, the period studied covers the flexibilization of the labor market through reforms of monopolistic guild privileges and the eventual abolition of Spanish guilds in 1836. The proper handling of cargo and the mode of work influenced – but did not determine – occupational and organizational cultures: some guilds operated cooperatively, others, individually. These corporations were organized horizontally – there were no apprentices or journeymen in these trades, only masters – and developed alternative methods for organizing work processes, determining recruitment qualification, and for developing and transmitting skills. The investigation looks at the internal and external considerations that influenced the organizational responses to liberalism. The traditional (and arguably still generally dominant) historiography of guilds centers on discontinuity between the guilds and later organizations of labor and capital (trade unions and owners’ associations). This investigation highlights a number of direct continuities, contributing to the study of the development of capitalism. The principal conclusions of the research are focused on a number of related considerations, including: port types and infrastructures; the objective, cargo-based necessities of handling; work cultures, organizational cultures, and organizational models, (especially collaborative or individualistic activities); leveling mechanisms and the socio-economic composition of the guilds (vis à vis internal and external employment schemes), and the responses to liberalization (which is shown to have developed progressively over decades).

[spa] Esta tesis tiene como objetivo elucidar el sub-sector del manejo de la carga marítima en Barcelona (1760-1840) para mejor entender la función de los gremios de servicios. En especial analiza como reaccionaron estos gremios al desarrollo progresivo del liberalismo, que representó un reto considerable al sistema gremial. De esta manera, la tesis contribuye a la historiografía de los estudios de gremios europeos y de la historia de trabajo en el ámbito marítimo. Es notable que el objeto de estudio se encuentre como un outlier (o, caso atípico) en varios campos, ya que en los estudios de gremios hay poca atención puesta en el sector de servicios, y en los estudios de trabajo marítimo hay muy pocas investigaciones sobre la época artesanal. A nivel de historia local, existen unas pocas publicaciones sobre los gremios tratados aquí, pero en su mayoría se enfocan en un solo gremio, desconectado del resto de componentes del universo del trabajo portuario. Entre los temas tratados se encuentran: el análisis del sistema gremial europeo en general y la diferenciación de éstos gremios de servicios; un acercamiento al entendimiento socio-espacial del puerto (con casos comparativos); la definición socio-jurídica y económica de los gremios tratados; el avance progresivo del liberalismo en España y particularmente en Barcelona; y las estrategias de los diferentes gremios del sub-sector del manejo de la carga marítima frente las reformas y aboliciones liberales del sistema gremial. Basado en literatura secundaria principalmente en castellano, catalán e inglés, y en fuentes primarias mayoritariamente en castellano, la tesis se presenta en inglés, con un resumen exhaustivo en castellano. Las conclusiones se analizan a partir del objetivo y su relevancia a varios campos académicos.

Application of a statistical method for the traffic port prediction

Scipedia content — Tue, 26 Jan 2021 15:52:56 +0100

Maritime transport covers the immense majority of the world’s international trade, particularly for Spain, where it represents a 74% of the total transported goods. Most of this transport is made via containers, because of its versatility. Its drawback is that very specific infrastructure and large spaces are needed for its management, and these are not fast to build nor cheap. In addition, the inability to manage containers if the infrastructure is under work or has reached his maximum capacity may translate into important economic losses. To prevent this from happening it is mandatory to plan in advance, and that means accept some predictions of the future to act accordingly. There is a wide range of accepted forecasting methods, because none is good in every situation, and predicting container throughput is not an exception. In this project, we will discuss the validity of Markov Chains when it comes to forecast maritime goods exchange, more precisely the total annual volume of TEUs. As real cases, we will take the data of 4 important Spanish ports (Algeciras, Barcelona, Tarragona and Valencia) from 1973 to 2015 and use it to create a prediction model. We will use the Markov property to create predictions and carry out Monte Carlo simulations to sample them. Over the sections we will change the input data and the parameters of the model to better understand the behavior of Markov chains when applied in such area. To have a reference, we will perform a witness forecast by means of a linear regression. An accuracy measure is planned for each of the models to assess a comparison between them, and find which one is more precise, and thus more valid. El transporte marítimo abarca la inmensa mayoría del comercio internacional en todo el mundo, y para España en particular, donde representa el 74% del total transportado. La mayor parte de este transporte se realiza en contenedores, por lo versátiles que resultan. Lo malo de este sistema es que se necesita una infraestructura específica y mucho espacio para poder procesarlos, lo cual tarda tiempo en construirse e implica grandes inversiones. Además, el hecho de no poder recibir contenedores por remodelaciones en la infraestructura o esta ha llegado a su máximo puede traducirse en cuantiosas pérdidas económicas. Para evitar que esto ocurra es de vital importancia planear de antemano, lo cual implica aceptar una predicción y actuar en consecuencia. Existe un amplio abanico de métodos predictivos, esto se debe a que ninguno de ellos es válido en todas las situaciones posibles, y en el ámbito del transporte marítimo no es una excepción. En este Proyecto discutiremos la validez de las cadenas de Márkov a la hora de prever el intercambio de mercancías por vía marítima, más concretamente el número total de TEUs por año. Como estudiar casos reales tomaremos los datos de 4 importantes puertos españoles (Algeciras, Barcelona, Tarragona and Valencia) desde 1973 hasta 2015 y los utilizaremos para probar el modelo. Utilizaremos la propiedad de Márkov para crear las predicciones y llevaremos a cabo simulaciones Monte Carlo con el fin de muestrearlas. A través de los diferentes apartados iremos cambiando los datos y los parámetros del modelo para entender mejor el comportamiento de las cadenas de Márkov cuando se aplican en esta área en particular. Para tener una referencia, utilizaremos como experimento testigo una predicción realizada con una regresión lineal. Está planeada también una medida de la precisión de cada uno de los modelos, para poder así compararlos y evaluar cuál es el que mejor se ajusta a la realidad, y por lo tanto es el más valido.

Modeling and forecasting the load in the future electricity grid : Spatial electric vehicle load modeling and residential load forecasting

Scipedia content — Tue, 26 Jan 2021 15:52:43 +0100

The energy system is being transitioned to increase sustainability. This transition has been accelerated by the increased awareness about the adverse effects of the greenhouse gas (GHG) emissions into the atmosphere. The transition includes switching to electricity as the energy carrier in some sectors, e.g., transportation, increasing the contribution of renewable energy sources (RES) to the grid, and digitalizing the grid services. Electric vehicles (EVs) are promoted and subsidized in many countries among the sustainability initiatives. Consequently, the global sales of EVs rapidly increased in the recent years. Many EV owners might charge their EVs only at home, thereby increasing the residential load. The residential load might further increase due to the initiatives to electrify the heating/cooling sector. This thesis contributes to the knowledge about the operation of the future energy system by modeling the spatial charging load of private EVs in cities, and by proposing a forecasting model to predict the residential load. Both models can be used to evaluate the impacts of both technologies on the local electricity grid. In addition, demand response (DR) schemes can be proposed to reduce the adverse effects of both the charging load of EVs and the residential load. A case study of the EV model on the Herrljunga city grid showed that 100% EV penetration with 3.7 kW (charging rate of 14.8 km/h) chargers will not cause voltage violations in the grid. Winter load is responsible for 5% voltage drop at the weakest bus, and EVs add only 1% to this drop. In a Swedish city, charging EVs will require adding extra 1.43 kW/car to the grid capacity—assuming 22 kW (charging rate of 88 km/h) residential chargers. If the EV charging is not restricted to residential locations, an increase of 1.23 kW/car is expected. The proposed forecasting model is comparable in accuracy to previously developed models. As an advantage, the model produces a probability density function (PDF) describing the model’s certainty in the forecast. In contrast, many previous contributions provided only point forecasts.

The Curitiba plan 1965-1975: unfolding of another modern Brazilian

Scipedia content — Tue, 26 Jan 2021 15:50:47 +0100

tese trata da concepção e da implantação do Plano de Curitiba, no período de 1965a 1975. O marco inicial é a elaboração do Plano Preliminar de Urbanismo de Curitiba, um trabalho coordenado pelo arquiteto Jorge Wilheim e executado com a colaboração de uma equipe de arquitetos de Curitiba, grupo esse que dará origem ao Instituto de Pesquisa e Planejamento Urbano de Curitiba (IPPUC), em 1965. Os fatos urbanos resultantes do Plano de Curitiba revelam o desenho de uma estrutura urbana linear que conjuga transporte coletivo com uso do solo multifuncional. A estrutura urbana é tangencial ao centro da cidade, permitindo a transformação da Rua XV de Novembro em área de pedestres. O Plano de Curitiba é identificado como um processo sequencial e um trabalho coletivo, sendo que, para efeito de sistematização, o intervalo temporal é subdividido em dois períodos, notadamente: concepção (1965-1970), e implantação (1971-1975). Concomitante à investigação do Plano de Curitiba, também se objetiva pesquisar o desenvolvimento e as transformações do projeto urbano no após-Guerra, com especial interesse no ambiente intelectual e nos projetos de arquitetura e urbanismo no âmbito do Team 10. O método estipulado divide a pesquisa em duas partes, com investigação sobre a evolução e projeto da cidade moderna no após-Guerra, e a evolução e projeto da cidade de Curitiba, com o objetivo de relacioná-los. Concatenadas com o método, as amostras foram coletadas principalmente em dois arquivos de projetos, no Het Nieuwe Instituut, em Rotterdam - vinculado a uma pesquisa realizada na Delft University of Technology (TU Delft), na Holanda -, e no arquivo da Biblioteca IPPUC, em Curitiba. Como resultado, defende-se a hipótese do Plano de Curitiba como um desdobramento de outro moderno brasileiro. The thesis is about the conception and implantation of Curitiba\\'s Plan, from 1965 to1975. The initial milestone is the elaboration of Curitiba\\'s Urban Preliminary Plan, a study coordinated by architect Jorge Wilheim and executed with the collaboration from a team of architects from Curitiba, this group will later start the Institute of Research and Urban Planning of Curitiba (IPPUC), in 1965. The urban facts resulting from Curitiba\\'s Plan show the drawing of a linear urban structure, which joins a multifunctional land use with public transportation system. The urban structure is tangential to the city downtown, allowing the renewing of XV de Novembro Street to a pedestrian area. Curitiba\\'s Plan is identified as a sequential process and a group work, whereby, for a systematic organization the time gap is subdivided in two periods, notably: conception (1965-1970), and implantation (1971-1975). Simultaneous to the investigation of Curitiba\\'s Plan, also aims to research the development and changes of the urban design in the Post-War, with special interest in the intellectual environment and the architecture and urbanism projects in the Team 10 context. The stipulated method divides the research in two parts, with the investigation about the evolution and project of the modern city in the Post-War, and the evolution and project of the city of Curitiba, aiming to relate them. Correlated with the method, the samples were collected mainly from two archives of projects, at Het Nieuwe Instituut, in Rotterdam -related to a research done at Delft University of Technology (TU Delft), in Holland -, and the archives from IPPUC Library, in Curitiba. As a result, the hypothesis of Curitiba\\'s Plan as an unfolding of another Brazilian Modern is defended.

Conception des principes de coopération conducteur-véhicule pour les systèmes de conduite automatisée

Scipedia content — Tue, 26 Jan 2021 15:42:04 +0100

Given rapid advancement of automated driving (AD) technologies in recent years, major car makers promise the commercialization of AD vehicles within one decade from now. However, how the automation should interact with human drivers remains an open question. The objective of this thesis is to design, develop and evaluate interaction principles for AD systems that can cooperate with a human driver. Considering the complexity of such a human-machine system, this thesis begins with proposing two general cooperation principles and a hierarchical cooperative control architecture to lay a common basis for interaction and system design in the defined use cases. Since the proposed principles address a dynamic driving environment involving manually driven vehicles, the AD vehicle needs to understand it and to share its situational awareness with the driver for efficient cooperation. This thesis first proposes a representation formalism of the driving scene in the Frenet frame to facilitate the creation of the spatial awareness of the AD system. An adaptive vehicle longitudinal trajectory prediction method is also presented. Based on maneuver detection and jerk estimation, this method yields better prediction accuracy than the method based on constant acceleration assumption. As case studies, this thesis implements two cooperation principles for two use cases respectively. In the first use case of highway merging management, this thesis proposes a cooperative longitudinal control framework featuring an ad-hoc maneuver planning function and a model predictive control (MPC) based trajectory generation for transient maneuvers. This framework can automatically handle a merging vehicle, and at the mean time it offers the driver a possibility to change the intention of the system. In another use case concerning highway lane positioning and lane changing, a shared steering control problem is formulated in MPC framework. By adapting the weight on the stage cost and implementing dynamic constraints online, the MPC ensures seamless control transfer between the system and the driver while conveying potential hazards through haptic feedback. Both of the designed systems are evaluated through user tests on driving simulator. Finally, human factors issue and user’s perception on these new interaction paradigms are discussed.; Face à l’évolution rapide des technologies nécessaires à l’automatisation de la conduite au cours de ces dernières années, les grands constructeurs automobiles promettent la commercialisation de véhicules autonomes à l’horizon 2020. Cependant, la définition des interactions entre les systèmes de conduite automatisée et le conducteur au cours de la tâche de conduite reste une question ouverte. L'objectif de cette thèse est de concevoir, développer et évaluer des principes de coopération entre le conducteur et les systèmes de conduite automatisée. Compte tenu de la complexité d'un tel Système Homme-Machine, la thèse propose, en premier lieu une architecture de contrôle coopératif hiérarchique et deux principes de coopération généraux sur deux niveaux dans l’architecture qui serviront ensuite de base commune pour la conception des systèmes coopératifs développés pour les cas d’usages définis. Afin d’assurer une coopération efficace avec le conducteur dans un environnement de conduite dynamique, le véhicule autonome a besoin de comprendre la situation et de partager sa compréhension de la situation avec le conducteur. Pour cela, cette thèse propose un formalisme de représentation de la scène de conduite basé sur le repère de Frenet. Ensuite, une méthode de prédiction de trajectoire est également proposée. Sur la base de la détection de manœuvre et de l'estimation du jerk, cette méthode permet d’améliorer la précision de la trajectoire prédite comparée à celle déterminée par la méthode basée sur une hypothèse d'accélération constante. Dans la partie d’études de cas, deux principes de coopération sont mis en œuvre dans deux cas d’usage. Dans le premier cas de la gestion d’insertion sur autoroute, un système de contrôle longitudinal coopératif est conçu. Il comporte une fonction de planification de manœuvre et de génération de trajectoire basée sur la commande prédictive. En fonction du principe de coopération, ce système peut à la fois gérer automatiquement l’insertion d’un véhicule et donner la possibilité au conducteur de changer la décision du système. Dans le second cas d'usage qui concerne le contrôle de trajectoire et le changement de voie sur autoroute, le problème de partage du contrôle est formulé comme un problème d’optimisation sous contraintes qui est résolu en ligne en utilisant l’approche de la commande prédictive (MPC). Cette approche assure le transfert continu de l’autorité du contrôle entre le système et le conducteur en adaptant les pondérations dans la fonction de coût et en mettant en œuvre des contraintes dynamiques en ligne dans le modèle prédictif, tout en informant le conducteur des dangers potentiels grâce au retour haptique sur le volant. Les deux systèmes sont évalués à l’aide de tests utilisateur sur simulateur de conduite. En fonction des résultats des tests, cette thèse discute la question des facteurs humains et la perception de l'utilisateur sur les principes de coopération.

The electric vehicle relocation problem

Scipedia content — Tue, 26 Jan 2021 15:40:28 +0100

Traditional car-sharing services are based on the two-way scheme, where the user picks up and returns the vehicle at the same parking station. Some services also allow one-way trips, where the user can return the vehicle in a different station. The one-way scheme is more attractive for users, but may pose a problem in the distribution of the vehicles, due to a possible unbalanced equation between the user’s demand and the availability of vehicles or free slots at the stations. This issue becomes more complex in the case of electric car sharing, where the travel range depends on the state-of-charge of the vehicles. In a previous work, Bruglieri et al. introduced a new approach to relocate the vehicles where cars were moved by personnel of the service operator to keep the system balanced. Such relocation method generates a new challenging pickup and delivery problem called Electric Vehicle Relocation Problem (E-VReP). Consequently, Bruglieri et al. introduced a method to forecast the unbalancing of a car-sharing system. They applied such method to the data yielded by the Milan transport agency, taking into account the location and capacity of charging stations in Milan. Finally, some years later, they introduced the economic sustainability of the relocation approach, introducing a revenue associated to each request, and a cost associated with each operator. In the proposed new model, authors want to add two new features to the E-VReP. The first one is the implementation of a working day with two work shifts. Until now each operator could start working at different times. With this new feature, we set two shifts each day, one in the morning, and one in the afternoon. The second novelty is the possibility for operators to collaborate among them. This means that operators can carpool in an EV in order to reach their destinations faster than if they tried reaching it by bike. In this way, using a Mixed Integer Linear Programming (MILP) formulation of E-VReP, we can estimate the advantages of our relocation approach on verisimilar instances.

Outgoing

Viability and Applicability of Simplified Models for the Dynamic Analysis of Ballasted Railway Tracks

Scipedia content — Tue, 26 Jan 2021 15:38:52 +0100

The numerical models of the railway track are fundamental tools for the study of their dynamic behaviour, with implications for the safety and comfort of rail transport and the degradation and need for maintenance of the track. The importance of these models has increased alongside the speed and capacity of the railway vehicles over the last decades. Although the use of three-dimensional finite element models is becoming common practice, simplified models are still relevant, due to their simplicity of implementation and results interpretation, and low computational cost. However, the general validity of these models has not yet been demonstrated in the relevant literature. The present thesis aims to establish the applicability and viability of such simplified models in the analysis of the dynamic behaviour of the ballasted railway track. The following questions are considered: 1. Are these models able to approximate the real rail displacement due to the passage of rail vehicles, despite their simplicity? 2. If yes, for which situations (i.e., track properties and loading conditions) can they be used reliably? 3. In these situations, is it possible to define adequate parameters for the simplified models based on the track’s geometry and mechanical properties? To that end, three linear elastic models are implemented: a detailed three-dimensional finite element model, a one-dimensional beam in discrete supports model, and a one-dimensional beam on elastic foundation model. Transient and steady-state dynamic solutions for a load moving at moderate and high speed are obtained. The vertical displacement of the rail is chosen as the reference to measure the equivalence between the models, since it is a common element between all models and is the interface between the load and the track. The three-dimensional model is validated by comparison with published experimental measurements. Its results cover a representative range of the properties of the ballast and subgrade, and are used as a reference to calibrate the simplified models using genetic algorithms and non-linear programming. It is concluded that a good approximation to the reference solution can be achieved, particularly when the load moves slower than the velocity of propagation of the elastic waves in the soil. For high velocities and/or soft soils, the wave propagation becomes more relevant to the dynamic behaviour of the track, and the simplified models become less reliable. Following a review of the existing literature, theoretical expressions for the determination of the parameters of the simplified models are proposed. It is concluded that these are suitable for the beam on discrete supports model, but not for the beam on elastic foundation model, whose optimum parameters are less consistent across the different properties of the track and load speeds.

Automated Traffic Time Series Prediction

Scipedia content — Tue, 26 Jan 2021 15:37:14 +0100

Intelligent transportation systems (ITS) are becoming more and more effective. Robust and accurate short-term traffic prediction plays a key role in modern ITS and demands continuous improvement. Benefiting from better data collection and storage strategies, a huge amount of traffic data is archived which can be used for this purpose especially by using machine learning. For the data preprocessing stage, despite the amount of data available, missing data records and their messy labels are two problems that prevent many prediction algorithms in ITS from working effectively and smoothly. For the prediction stage, though there are many prediction algorithms, higher accuracy and more automated procedures are needed. Considering both preprocessing and prediction studies, one widely used algorithm is k-nearest neighbours (kNN) which has shown high accuracy and efficiency. However, the general kNN is designed for matrix instead of time series which lacks the use of time series characteristics. Choosing the right parameter values for kNN is problematic due to dynamic traffic characteristics. This thesis analyses kNN based algorithms and improves the prediction accuracy with better parameter handling using time series characteristics. Specifically, for the data preprocessing stage, this work introduces gap-sensitive windowed kNN (GSW-kNN) imputation. Besides, a Mahalanobis distance-based algorithm is improved to support correcting and complementing label information. Later, several automated and dynamic procedures are proposed and different strategies for making use of data and parameters are also compared. Two real-world datasets are used to conduct experiments in different papers. The results show that GSW-kNN imputation is 34% on average more accurate than benchmarking methods, and it is still robust even if the missing ratio increases to 90%. The Mahalanobis distance-based models efficiently correct and complement label information which is then used to fairly compare performance of algorithms. The proposed dynamic procedure (DP) performs better than manually adjusted kNN and other benchmarking methods in terms of accuracy on average. What is better, weighted parameter tuples (WPT) gives more accurate results than any human tuned parameters which cannot be achieved manually in practice. The experiments indicate that the relations among parameters are compound and the flow-aware strategy performs better than the time-aware one. Thus, it is suggested to consider all parameter strategies simultaneously as ensemble strategies especially by including window in flow-aware strategies. In summary, this thesis improves the accuracy and automation level of short-term traffic prediction with proposed high-speed algorithms.

Challenges in Partially Automated Driving : A Human Factors Perspective

Scipedia content — Tue, 26 Jan 2021 15:36:35 +0100

The technological development in recent years is currently reflected in the implementation of more and more advanced driver assistance systems (ADAS). A clear example is found in the automated driving systems being marketed today. Some of these systems are capable of controlling crucial driving tasks such as keeping the vehicle within the lane or maintaining speed and the distance with the front vehicle constant. While this technology is still not mature enough to allow fully autonomous driving, current systems allow partially automated driving, or Level 2 (SAE, 2016). Level 2 automation enables feet-free, and for short periods hands-free driving, under specific situations. Yet, the driver is still expected to monitor the road and the system and be ready to intervene when required by the system. Regarding this, studies from the driving and other domains have warned about potential performance problems associated with placing operators in such monitoring role. Factors such as vigilance decrements or proneness to engage in other activities have been proposed to explain these problems; however, their role in the context of Level 2 automation remains to be further investigated. In this context, the main aims of this thesis were to understand the attentional effects of monitoring a Level 2 automated system and to investigate drivers’ strategies to integrate additional tasks while using such system. In particular, the following research questions were established: 1) Does monitoring a Level 2 system affect driver attention after short driving periods?; 2) Does Level 2 automation facilitate the performance of additional tasks?; 3) How do drivers integrate additional tasks into their monitoring responsibilities, and how is that influenced by automation trust and experience?. A complementary aim of this thesis was to explore the applicability of the event-related potentials (ERPs) technique to detect the effects of different types of ADAS, i.e. Level 2 automation and a visual in-vehicle information system (IVIS), on drivers’ attention and on specific processing resources. Three studies were conducted to address the aforementioned research questions. In Study I and III, the participants were asked to drive Level 2 automated and manually while performing an auditory oddball task (Study I) or a visuomotor task (Study III). In Study II, the participants were instructed to perform a computer tracking task with or without the support of an artificial visual IVIS while executing a secondary auditory oddball task. Measurements included performance indicators from the primary and secondary tasks, as well as subjective and psychophysiological measures. ERPs (N1 and P3 amplitude and latencies) elicited by the auditory oddball task were used to assess the participants’ attentional resource allocation. Glance behaviour was also recorded to analyse drivers’ visual monitoring strategies in Study III. In addition, subjective measures of mental workload, vigilance or automation trust were collected. Last, driving parameters such as speed, time spent on the left lane or number overtakings were used to account for driving strategies to integrate an additional task while driving Level 2 automated or manually (Study III). As hypothesized, monitoring a Level 2 automated system for short periods led to lower perceived demands and to reductions in the allocation of attentional resources to the auditory oddball task, as shown by lower amplitudes in the P3 component (Study I). In Study III, driving Level 2 automated led to worse performances on an additional visuomotor task, compared to when driving manually, which contradicted our expectations. Additionally, when the system was active, drivers tended to look less to the road and more to the dashboard; however, only drivers with automation experience or who perceived the system as more robust increased their visual attention to the additional task. Furthermore, the results from Study II showed that some specific ERPs parameters, namely N1 latency and P3 amplitude, were also sensitive to the demands of IVIS while performing the tracking task. Based on previous studies (Young and Stanton, 2002), the lower attentional resource allocation observed in Study I could reflect a cognitive underload effect induced by the Level 2 automated driving. Cognitive underload is proposed as one of the explaining mechanisms for the observed worse performances in the additional visuomotor task during the automated conditions in Study III. However, other effects such as overload or task interferences could also explain this. Finally, the results revealed by the ERPs in Studies I and II suggest that this could be a useful technique to detect alterations in drivers’ attention due to the excessive high or low demands placed by different ADAS. ERPs also showed a greater diagnosticity than other measures in the detection of specific task requirements of perceptual and cognitive resources. Thus, ERPs may be useful as a complementary tool to other mental workload measures. Given that drivers need to remain attentive at all times while interacting with a Level 2 automated vehicle, the use of countermeasures to mitigate the negative attentional effects reported in this thesis is highly recommended. Specific training programs enhancing drivers’ knowledge of the system or the implementation of systems that inform about the system reliability or detect inadequate driver states could be promising solutions. Ägare av fordon med nivå 2-automation har nu möjlighet att köra utan att använda pedalerna, och under korta perioder, även utan att behöva styra i specifika trafiksituationer. Emellertid förblir de fortfarande ansvariga för att kontinuerligt övervaka den omgivande trafikmiljön liksom det automatiserade systemet. Även om automatiserade fordon har potential att öka säkerheten, har tidigare studier visat på betydande problem förknippade med förares svårigheter att övervaka automatiserade system en längre tid. Denna avhandlings huvudsakliga syfte var att förstå vilken inverkan nivå 2- automatiserad körning har på förares uppmärksamhet och beteende under två situationer: a) då föraren övervakar trafiken och systemet, b) då föraren övervakar trafiken och systemet, och samtidigt utför en sidouppgift av visumotorisk karaktär. Dessutom undersöktes även vilken inverkan tillit till och erfarenhet av nivå 2-automation hade på förarens övervakningsstrategier av och användning av systemet. Ett ytterligare, kompletterande syfte med denna avhandling, var att undersöka användbarheten av event-related potentials (ERP) -tekniken för att bättre kunna detektera eventuella förändringar som förknippas med nivå 2-automation. Specifikt analyserades N1 och P3 ERP-komponenterna. Dessutom användes denna teknik i avhandlingen för att upptäcka ökning av den mentala arbetsbelastningen i samband med förarens interaktion med andra vanliga stödsystem, exempelvis fordonets informationssystem. Tre olika studier genomfördes. I Studie I (simulatorstudie) observerades att körning med nivå 2- automation under korta perioder medförde generella minskningar av uppmärksamhetsresursallokering. Denna effekt upptäcktes som en minskning av amplituden hos P3-komponenten, framkallad av utförandet av en sekundär auditiv uppgift. I Studie III (på väg) upptäcktes sämre prestation på en sidouppgift av visumotorisk karaktär under körning med nivå-2 automation jämfört med manuell körning. Det observerades även att förare med större erfarenhet av systemet och/eller högre skattningar av systemets robusthet, tenderade att titta mindre på vägen och mer på sidouppgiften. Slutligen, i Studie II (laboratoriestudie), upptäcktes att ERP var användbart för att detektera ökningar av krav associerade med utförandet av en datoradministrerad spårningsuppgift, baserad på ett artificiellt visuellt IVIS. I allmänhet tyder resultaten i denna avhandling på att nivå 2-automation kan leda till kognitiv underbelastning, en effekt som tidigare har observerats i högre grader av automation. Nedsättning av uppmärksamhet, beroende på kognitiv underbelastning, kan förklara de sämre prestationerna på sidouppgiften under körning med nivå 2-automation som observerades i studie III. Dock behöver resultatet undersökas ytterligare eftersom andra effekter, som överbelastning eller specifik uppgiftskonkurrens, också kan ha skett. I enlighet med avhandlingens kompletterande syfte, uppvisade användningen av ERP, som ett komplementärt verktyg till andra sätt att mäta mental arbetsbelastning, lovande resultat. ERP kan användas för att upptäcka ytterligare effekter av olika stödsystem, som antingen ökar eller minskar de krav som ställs på föraren. Nu finns fordon med nivå 2-automation på vägarna. Trots detta är vissa säkerhetsproblem, förknippade med deras effekter på förarens förmågor och beteende, fortfarande olösta. Det är därför nödvändigt att insatser görs för att mildra sådana problem så att framtida incidenter i trafiken kan förhindras i så stor utsträckning som möjligt. Förhoppningsvis bidrar denna avhandling till att öka förståelsen för de verkliga effekterna av nivå 2-system på förare och uppmuntrar till fler framtida studier inom området.

Perceived Accessibility : Living a satisfactory life with help of the transport system

Scipedia content — Tue, 26 Jan 2021 15:32:43 +0100

This thesis fills a gap in contemporary transport research and planning as it introduces perceived accessibility as a theoretical and methodological concept for incorporating the individual dimension of accessibility in current practice. Perceived accessibility is defined as “how easy it is to live a satisfactory life with the help of the transport system”, and is proposed as a complement to objective measures and understandings of accessibility. The thesis includes three studies. Study I developed a measure for capturing perceived accessibility with a specific transport mode, based on theories and conceptualizations of accessibility. Study II looked at determinants of perceived accessibility, and Study III further developed the measure of perceived accessibility to include actual travel (combinations of transport modes), and explored the relation between perceived accessibility and objectively measured accessibility for the same geographical area in Sweden. In all, the thesis provides background ideas and theory on perceived accessibility, and a validated quantitative approach to capturing perceived accessibility in day-to-day travel. Empirical findings further support the complementary nature of the approach and results indicate that assessments of perceived accessibility may be helpful in determining where to direct interventions aiming at improving accessibility by evaluating different transport modes or different segments of individuals. The method developed for capturing perceived accessibility shows merit in contributing to further theory development on accessibility by its ability to identify determinants of perceived accessibility and its potential in identifying segments of the population that experience significantly lower accessibility than other groups, and thus are at risk of experiencing social exclusion or suffer from transport disadvantage. This thesis introduces perceived accessibility as a theoretical and methodological concept for including the individual dimension of accessibility in transport research and planning. Perceived accessibility is defined as “how easy it is to live a satisfactory life with the help of the transport system”, and as it captures individual experiences and abilities, it is proposed as a complement to objective measures and understandings of accessibility. The thesis includes three studies. Study I developed a measure for capturing perceived accessibility with a specific transport mode, based on theories and conceptualizations of accessibility. Study II looked at determinants of perceived accessibility, and Study III further developed the measure of perceived accessibility to include actual travel (combinations of transport modes), and explored the relation between perceived accessibility and objectively measured accessibility for the same geographical area in Sweden. In all, the thesis provides background ideas and theory on perceived accessibility, a validated quantitative approach to capturing perceived accessibility in day-to-day travel, and empirical findings supporting the complementary nature of the approach and its potential to differentiate between individuals. Mistra SAMS (Sustainable Accessibility and Mobility Services)

Energy Efficient Traffic Engineering in Software Defined Networks

Scipedia content — Tue, 26 Jan 2021 15:31:58 +0100

This work seeks to improve the energy efficiency of backbone networks by automatically managing the paths of network flows to reduce the over-provisioning. Compared to numerous works in this field, we stand out by focusing on low computational complexity and smooth deployment of the proposed solution in the context of Software Defined Networks (SDN). To ensure that we meet these requirements, we validate the proposed solutions on a network testbed built for this purpose. Moreover, we believe that it is indispensable for the research community in computer science to improve the reproducibility of experiments. Thus, one can reproduce most of the results presented in this thesis by following a couple of simple steps. In the first part of this thesis, we present a framework for putting links and line cards into sleep mode during off-peak periods and rapidly bringing them back on when more network capacity is needed. The solution, which we term ``SegmenT Routing based Energy Efficient Traffic Engineering'' (STREETE), was implemented using state-of-art dynamic graph algorithms. STREETE achieves execution times of tens of milliseconds on a 50-node network. The approach was also validated on a testbed using the ONOS SDN controller along with OpenFlow switches. We compared our algorithm against optimal solutions obtained via a Mixed Integer Linear Programming (MILP) model to demonstrate that it can effectively prevent network congestion, avoid turning-on unneeded links, and provide excellent energy-efficiency. The second part of this thesis studies solutions for maximizing the utilization of existing components to extend the STREETE framework to workloads that are not very well handled by its original form. This includes the high network loads that cannot be routed through the network without a fine-grained management of the flows. In this part, we diverge from the shortest path routing, which is traditionally used in computer networks, and perform a particular load balancing of the network flows. In the last part of this thesis, we combine STREETE with the proposed load balancing technique and evaluate the performance of this combination both regarding turned-off links and in its ability to keep the network out of congestion. After that, we use our network testbed to evaluate the impact of our solutions on the TCP flows and provide an intuition about the additional constraints that must be considered to avoid instabilities due to traffic oscillations between multiple paths.; Ce travail a pour but d'améliorer l'efficacité énergétique des réseaux de cœur en éteignant un sous-ensemble de liens par une approche SDN (Software Defined Network). Nous nous différencions des nombreux travaux de ce domaine par une réactivité accrue aux variations des conditions réseaux. Cela a été rendu possible grâce à une complexité calculatoire réduite et une attention particulière au surcoût induit par les échanges de données. Pour valider les solutions proposées, nous les avons testées sur une plateforme spécialement construite à cet effet.Dans la première partie de cette thèse, nous présentons l'architecture logicielle ``SegmenT Routing based Energy Efficient Traffic Engineering'' (STREETE). Le cœur de la solution repose sur un re-routage dynamique du trafic en fonction de la charge du réseau dans le but d'éteindre certains liens peu utilisés. Cette solution utilise des algorithmes de graphes dynamiques pour réduire la complexité calculatoire et atteindre des temps de calcul de l'ordre des millisecondes sur un réseau de 50 nœuds. Nos solutions ont aussi été validées sur une plateforme de test comprenant le contrôleur SDN ONOS et des commutateurs OpenFlow. Nous comparons nos algorithmes aux solutions optimales obtenues grâce à des techniques de programmation linéaires en nombres entiers et montrons que le nombre de liens allumés peut être efficacement réduit pour diminuer la consommation électrique tout en évitant de surcharger le réseau.Dans la deuxième partie de cette thèse, nous cherchons à améliorer la performance de STREETE dans le cas d’une forte charge, qui ne peut pas être écoulée par le réseau si des algorithmes de routages à plus courts chemins sont utilisés. Nous analysons des méthodes d'équilibrage de charge pour obtenir un placement presque optimal des flux dans le réseau.Dans la dernière partie, nous évaluons la combinaison des deux techniques proposées précédemment : STREETE avec équilibrage de charge. Ensuite, nous utilisons notre plateforme de test pour analyser l'impact de re-routages fréquents sur les flux TCP. Cela nous permet de donner des indications sur des améliorations à prendre en compte afin d'éviter des instabilités causées par des basculements incontrôlés des flux réseau entre des chemins alternatifs. Nous croyons à l'importance de fournir des résultats reproductibles à la communauté scientifique. Ainsi, une grande partie des résultats présentés dans cette thèse peuvent être facilement reproduits à l'aide des instructions et logiciels fournis.

Modeling, Optimization and Analysis of Electromobility Systems

Scipedia content — Tue, 26 Jan 2021 15:30:10 +0100

Due to an increase in environmental awareness and an improved understanding on the impact of human activity on our planet’s climate, there is a strong desire both from governments and the general public to reduce harmful pollution and emissions. This requires action on different fronts, like decarbonizing electricity generation, industrial activity and not least the transport sector. This thesis aims to contribute to the development of a sustainable road transport system. There are several technologies that could achieve this goal, but the scope of this work is limited to automotive electrification in the form of hybrid and battery electric vehicles. Such vehicles currently seem to be the most promising technology, having a larger market share than e.g fuel cell electric vehicles. In order to increase the pace of automotive electrification it is necessary to understand the factors that are currently hindering its adoption. First, the higher cost of electrified vehicles when compared with their conventional counterpart is seen by most potential buyers as their main drawback, despite lower operating and maintenance costs. Second, their limited range and long recharging times cause range anxiety on the drivers and generate concerns over the capabilities of the vehicles to provide the expected service and level of convenience. Finally, the lack of charging infrastructure poses a challenge for potential users.In order to develop an understanding on how to address these issues, the present work takes a holistic approach that starts with the development of performance and cost models for the main components required in an electromobility system. These models are used to optimize the design of an electric powertrain for passenger vehicles. Three electrical machine topologies and two powertrain concepts are considered in this optimization. The results point out that significant cost benefits can be obtained from an increase in the top speed of the electric traction machine as well as the addition of a second speed to the transmission. Additionally, the developed methodology allows exploring a large space of search in a way that reduces development times and associated costs.Moving the focus to a higher level of abstraction, the described models are used to analyze the implications of deploying alternative forms of charging infrastructures in a national context. This analysis shows that a large deployment of a dynamic charging infrastructure accessible by both passenger and commercial vehicles significantly reduces the societal cost of electrification. This is due to the possibility of reducing the required battery capacity on-board the vehicles without affecting their driving range.

Smart Electric Vehicle Charging: Mitigating Supply-Demand Disparity Through User Incentives

Scipedia content — Tue, 26 Jan 2021 15:26:14 +0100

California has set the goal to source 100% of its electricity from renewable energy by 2045, up from 32% in 2017. Meanwhile, the growing mismatch between the renewable energy generation and peak demand is raising concerns on the electric grid's stability and efficiency. At the same time, electric vehicles are expected to reach 2.3 million in sales by 2050 in the US. The escalating load of electric vehicles amplifies load peaks and may exacerbate the existing supply-demand discrepancy. However, electric vehicle drivers are typically flexible in choosing the time to charge their vehicle batteries. This flexibility allows the electric vehicle drivers to shift their charging time and power to match the supply with little sacrifice or discomfort. As a result, incentives can be utilized to guide electric vehicle user behaviors to mitigate the grid's demand-supply discrepancy. Today, most existing solutions for the demand-supply disparity directly control the time and power of every load in the grid. But the forced control is difficult to implement for electric vehicles due to the lack of hardware support and commercial viability. Instead, incentives can motivate voluntary user behavior changes. This approach is more practical for large-scale deployments.This dissertation presents a smart electric vehicle charging system that incentivizes users to shift their charging time to match the renewable energy generation. The system applies non-monetary and monetary incentives by assigning charging priorities and awarding in-system virtual currency to users based on their consumption of renewable energy. Consequently, users with higher renewable energy consumption receive more power and faster service from the charging system. The effectiveness of the non-monetary incentives is demonstrated through two experiments conducted on the UCLA campus for 15 and 14 months respectively. The first experiment with four charging plugs and one solar panel measures users' willingness to manually change their consumption schedules to match the renewable energy generation. The results indicate that the solar consumption ratio has grown by 37% since the incentives were implemented. The second scaled-up experiment with 28 charging plugs and 2 solar panels introduced system algorithms to automatically control users' charging schedules when they choose so. The results reveal that more than 23% of the participants use the automatic programs regularly to improve their renewable energy usages.The incentive design and data analysis in this dissertation provide comprehensive insights on utilizing electric vehicles to mitigate demand-supply disparity through user behavior changes. Additionally, the experiment and system implementations provide practical experience on building effective interactions between the system and users.

Towards sustainable personal mobility with electric cars and buses

Scipedia content — Tue, 26 Jan 2021 15:25:56 +0100

The aim of this thesis was to explore if, and then how, electric cars and buses can contribute to sustainable personal mobility. Electric vehicles have increasingly been seen as a potential sustainable solution for the transport sector due to their high energy efficiency, close to zero emissions in the use phase, and the possibility to be powered by electricity from renewable resources. However, there are concerns about future scarcity of resources (e.g. lithium and cobalt for batteries), vehicle range, costs, high energy use in the production of batteries, as well as insufficient scientific support for how electric vehicles could be a part of a transition towards sustainability regarding personal mobility. The challenges for a fast transition towards sustainability are large and many. The transport sector is not contributing to such development, mainly due to emissions, use of fossil energy, and use of materials mined and recycled under unacceptable conditions. Furthermore, existing societal goals (e.g. fossil-fuel independent vehicle fleet by 2030 in Sweden, UN Agenda 2030, and the Paris agreement) are insufficient for sustainability and are not complemented by concrete plans or an approach for how to engage stakeholders and achieve coordinated actions for sustainability. The Framework for Strategic Sustainable Development includes a principled definition of sustainability that is necessary and sufficient for sustainability and procedural support for collaborative innovation for a strategic transition to fulfillment of that definition, which is why it has been used as an overarching methodology in this thesis. The research verified through several studies conditions for how electric vehicles can play a vital role in a strategic transition of personal mobility towards sustainability. Through stakeholder collaboration (e.g. interviews and workshops), a vision for sustainable transport with a focus on electric vehicles and an initial development plan towards that vision were designed. Several life cycle focused studies investigated (through calculations and data collection from literature, life cycle databases, interviews and workshops) about environmental and social impacts and costs for electric cars and buses. The stakeholder collaboration, combined with conceptual modelling, also resulted in models for generic support for multi-stakeholder collaboration and planning for strategic sustainable development of transport systems and communities, and for how to include electric buses in the procurement model of public transport. The strategic sustainable development perspective of this thesis broadens the analysis beyond the more common focus on climate change issues and should be able to reduce the risk of sub-optimizations in community and transport system development when applied in that context. The generic support for multi-stakeholder collaboration could potentially also promote a more participatory democratic approach to community development, grounded in a scientific foundation. "p"Contact the author to receive a pdf of the full thesis (papers included): sven.boren@bth.se or telephone +46455385723.

Coordination of Heavy-Duty Vehicle Platooning

Scipedia content — Tue, 26 Jan 2021 14:30:07 +0100

network-wide coordination system for heavy-duty vehicle platooning with the purpose of reducing fuel consumption is developed. Road freight is by far the dominating mode for overland transport with over 60 % modal share in the OECD countries and is thus critically important for the economy. Overcoming its strong dependency on fossil fuels and manual labor as well as handling rising congestion levels are therefore important societal challenges. Heavy-duty vehicle platooning is a promising near-term automated-driving technology. It combines vehicle-to-vehicle communication and on-board automation to slipstream in a safe manner, which can reduce fuel consumption by more than 10 %. However, in order to realize these benefits in practice, a strategy is needed to form platoons in an operational context. We propose a platoon coordination system that supports the process of automatically forming platoons over large geographic areas. We develop an architecture in which fleet management systems send start locations, destinations, and arrival deadlines to a platoon coordinator. By computing desirable speed profiles and by letting the vehicles' on-board systems track them, vehicles can meet en route and form platoons. Matching vehicles into platoons and deriving suitable speed profiles is treated as an optimization problem with the objective of maximizing the overall fuel savings under the constraint that vehicles arrive in time at their destinations. By updating the speed profiles and the platoon configurations based on real-time measurements of vehicle position and platoon state, the system can accommodate new vehicles joining on the fly. Using real-time measurements also makes the system resilient to disturbances and changing operating conditions. This thesis seeks to develop the theoretical foundations of such a system and evaluate its potential to improve transport efficiency. We first explore the coordination of vehicle pairs. Fuel-optimal speed profiles are derived. The uncertainty arising from traffic is taken into account by modeling travel time distributions and considering the probability of two vehicles successfully merging. Building on this coordination algorithm for vehicle pairs, we derive algorithms for larger platoons and vehicle fleets. This results in an NP-hard combinatorial optimization problem. The problem is formulated as an integer program and results on the solution structure are derived. In order to handle realistic fleet sizes with thousands of vehicles and continental sized geographical areas under real-time operation, heuristic algorithms are developed. The speed profiles resulting from the combinatorial optimization are further improved using convex optimization. Moreover, we derive efficient algorithms to identify all pairs of vehicles that can platoon. Simulations demonstrate that the proposed algorithm is able to compute plans for thousands of vehicles. Coordinating approximately a tenth of Germany's heavy-duty vehicle traffic, platooning rates over 65 % can be achieved and fuel consumption can be reduced by over 5 %. The proposed system was implemented in a demonstrator system. This demonstrator system has been used in experiments on public roads that show the technical feasibility of en route platoon coordination. Ett nätverksomfattande system för att koordinera körning i lastbilskolonner i syfte att minska bränsleförbrukningen utvecklas i denna avhandling.Vägtransport är med marginal det mest dominerande sättet för landtransport med en andel över 60 % i OECD-länderna och är således avgörande för samhällsekonomin. Dess starka beroende av fossila bränslen och arbetskraft samt ökande trängsel är därför viktiga utmaningar för samhället. Vägtransport är på väg att genomgå grundläggande förändringar genom elektrifiering, kommunikation och automation. Lastbilskolonnkörning är en teknologi för att automatisera fordon, som är redo att lanseras inom en snar framtid. Kolonnkörning kan ge bränslebesparingar på över 10 % tack vare att automatisering och kommunikation mellan fordon möjliggör så kallad slipstreaming på ett säkert sätt. Det behövs dock en strategi för att sätta ihop lastbilskolonner för att kunna dra nytta av denna teknologi. Vi föreslår därför ett automatiserat koordineringssystem som stödjer processen att sätta ihop lastbilskolonner inom stora geografiska områden. Vi utvecklar en arkitektur där fleet management system skickar start- och målpunkter samt senaste ankomsttid till koordineringssystemet. Genom att beräkna passande hastighetsprofiler och genom att låta lastbilarnas färddatorer följa dem kan lastbilar mötas på vägen och bygga ihop kolonner. Problemet att matcha fordon till kolonner och att komma fram till passande hastighetsprofiler hanteras som ett optimeringsproblem med målet att maximera den totala bränslebesparingen. Genom att uppdatera lösningen baserade på realtidsmätningar av fordonspositioner och kolonntillstånd kan systemet hantera tillkommande lastbilar och kan vara robust gentemot störningar och förändrade operativa förutsättningar. Denna avhandling strävar efter att utveckla teoretiska förutsättningar för ett sådant system och att utvärdera dess potential att öka transportsystemets effektivitet. Vi börjar med att undersöka koordinering av fordonspar och härleder bränsleoptimala hastighetsprofiler. Den osäkerhet som beror på trafiken tas hänsyn till genom att modellera hastighetsfördelningar och genom att betrakta sannolikheten att två fordon träffas och kan påbörja kolonnkörning. Vi bygger på denna algoritm för fordonspar för att härleda algoritmer som kan hantera större kolonner och större antal lastbilar. Det resulterar i ett NP-svårt kombinatoriskt optimeringsproblem. Problemet formuleras som ett heltalsoptimieringsproblem och vi kommer fram till resultat som visar strukturen av lösningen. Resulterande hastighetsprofiler förbättras ytterligare med hjälp av konvex optimering. Förutom detta utvecklas effektiva algoritmer för att identifiera alla fordonspar som kan köra i kolonn. Simuleringar demonstrerar att den föreslagna algoritmen klarar att beräkna planer för tusentals lastbilar. Vi visar att en samording av c:a 10 % av Tysklands lastbilstrafik kan tillåta att mer än 65 % av den totala körsträckan körs i kolonn och att bränsleåtgången kan minskas med mer än 5 %. Det presenterade systemet implementerades i ett demonstratorsystem. Experiment med demonstratorn på allmän väg har visat att koordinering av kolonnkörning på vägen är tekniskt genomförbart. "p"QC 20180403

Study of electric vehicle modeling and strategy of torque control for regenerative and anti-lock braking systems : Estudo de modelagem de veículos elétricos e estratégia de controle de torque para sistemas de frenagens regenerativa e antitravamento

Scipedia content — Tue, 26 Jan 2021 14:27:39 +0100

Orientador: José Antenor Pomilio Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Made available in DSpace on 2019-02-13T14:35:15Z (GMT). No. of bitstreams: 1 Paredes_MarinaGabrielaSadithPerez_D.pdf: 7267917 bytes, checksum: 9192ee8c7ba55261329908389d3a0b73 (MD5) Previous issue date: 2018 Resumo: Os veículos elétricos têm despertado crescente interesse devido à sua capacidade para reduzir a poluição no meio ambiente, usando elementos de energia elétrica acumulado em baterias e supercapacitores para o acionamento da máquina elétrica no lugar de um motor de combustão interna. Por outro lado, a baixa autonomia do veículo elétrico continua sendo uma barreira para seu sucesso comercial. Instituções automobilísticas junto com a Academia enfrentam esse desafio com diversas soluções para aumentar a energia disponível. Entre as possibilidades está a frenagem regenerativa. A frenagem regenerativa é um processo no qual recupera-se energia de um veículo durante as desacelerações. Esta pesquisa se concentra nas frenagens para diversas condições com mudanças da superficie da estrada, considerando o sistema de frenagem regenerativo e o sistema de antibloqueio. Analisamos e revisamos os aspectos básicos da modelagem de um veículo com/sem ABS, assim como o comportamento dinâmico das rodas e mostramos uma contribuição para o estudo do controle de torque na máquina e estratégias de controle para o torque distribuído na combinação e cooperação entre o torque elétrico e o mecânico, mesmo com mudanças do solo e de métodos de operação, como descidas, obtendo estabilidade do veículo e recuperação de energia Abstract: The interest in electric vehicles has grown worldwide due to their efficiency for reducing environmental pollution, by using energy elements such as batteries and supercapacitors to drive the electric machine, instead of an internal combustion engine. Contrarily, the low vehicle autonomy remains a barrier to their commercial success. Therefore, automotive institutions together with academics face the challenge through various solutions to increase the available energy. The regenerative braking is one of the implementations that helps a better use of the stored energy. Regenerative braking is a process in which energy is recovered from a vehicle during decelerations. This research focuses on braking for various road surface conditions. Furthermore, it considers the regenerative braking and the anti-lock braking systems regarding energy recovery performance for friction coefficient changes. In this work, we will review and analyze the basic aspects of the modeling of a vehicle with or without ABS, as well as the dynamic behavior of wheels. We will also present a contribution to the study of torque control and control strategies for the torque distribution regarding combination and co-operation between electric and mechanical torque. This process is done despite changes in ground surfaces and operating methods such as downhill, leading to better performance in the flexibility of vehicle stability and in the recovery of power Doutorado Energia Eletrica Doutora em Engenharia Elétrica 149810/2013-0 CAPES CNPQ

Topographic building pattern recognition with geospatial OpenStreetMap data

Scipedia content — Tue, 26 Jan 2021 14:09:53 +0100

This paper aims to explore the perceptual recognition of topographical building patterns from real-world OpenStreetMap data on virtual globes. An implementation was developed in which all geographical and contextual information was layered and, for the purpose of this study, what solely remained were building patterns as viewed from above. This was developed as a module for the planetarium visualization software Uniview. The aim was to determine how cities with different building patterns were perceived by participants in terms of size, scale, and building density. This was measured as the comparative difference between city pairs, that is, how much they differed in the percentage of the area that they covered. Two quantitative studies were conducted, one smaller controlled study with 19 participants and one larger online crowd-sourced study with 72 participants. The results show that participants are generally able to discern building patterns when the comparative difference is greater than a certain critical threshold. This critical threshold was determined to be at approximately 0.5% for both studies and for accuracy levels above 60%. Thus it was concluded that below this critical threshold users should be provided with visual feedback or other means of identifiers in order to allow for definite recognition, depending on what kind of information a certain type of visualization is trying to convey. Den här rapporten avser att utforska den perpetuella igenkänningen av topografiska byggnadsmönster genom att använda geografisk data från OpenStreetMap som avbildas på virtuella sfärer. En implementation utvecklades där geografisk data samt kontextuell information ordnades i överlappande lager som filtrerades, och där endast byggnadsmönster sett från ovan kvarstod. Denna modul utvecklades för Uniview som är en mjukvara för visualisering i planetarier. Målet var att avgöra hur deltagare uppfattade städer med olika byggnadsmönster med hänsyn till storlek, skala, samt byggnadsdensitet. Detta mättes genom den procentuella skillnaden mellan städer, dvs. skillnaden i procent för varje stads geografiska utsträckning. Två kvantitativa studier utfördes, en mindre kontrollerad studie med 19 deltagare samt en större nätbaserad studie med 72 deltagare. Resultatet visar att deltagare generellt kunde bedöma den procentuella skillnaden i byggnadsmönster upp till en viss kritisk gräns. Denna kritiska gräns fastställdes till runt 0.5% för båda studier och för noggrannhetsnivåer över 60%. Slutsatsen från detta är att användare bör ges visuella indikatorer för nivåer under denna kritiska gräns för att säkerställa definitiv igenkänning beroende på vilken information som skall förmedlas i en viss typ av visualisering.

Open for Business? Effects of Los Angeles Metro Rail Construction on Adjacent Businesses

Scipedia content — Tue, 26 Jan 2021 14:09:19 +0100

Recent court cases and news reports have focused on the effects of transit construction on business revenue and survival, yet the topic is underexplored in the scholarly literature. This paper examines whether transit construction negatively affected the revenue and survival of businesses along the second segment of the Los Angeles Metro Rail Red Line under Vermont and Hollywood Boulevards. Using National Establishment Time-Series business data, the research shows that business survival was significantly lower among businesses within 400 meters of stations, where cut and cover construction was used. A difference-in-differences technique was employed to determine whether revenue loss was the main mechanism by which businesses were displaced, but revenue loss was not found to be significant. The increased failure rate provides evidence that construction effects of mitigation programs for businesses should be standard practice when building new transit lines. Further research and data collection on business tenure are needed to understand the dynamics of business displacement around transit and to make such programs more effective.

The interaction between global liquid energy markets and global maritime transport market

Scipedia content — Tue, 26 Jan 2021 14:06:40 +0100

Σκοπός της παρούσας διπλωματικής εργασίας είναι να εξετάσει πώς αλληλεπιδρά η παγκόσμια αγορά υγρών ενεργειακών αγαθών με την παγκόσμια αγορά θαλάσσιων μεταφορών υγρών ενεργειακών αγαθών, ποίοι είναι οι παράγοντες που επηρεάζουν τις δυο αγορές, ποιες είναι οι τάσεις που επικρατούν επί του παρόντος, ποιες είναι προοπτικές ανάπτυξης αυτών και οι προβλέψεις για το μέλλον. Η πρώτη ενότητα αναλύει την αγορά υγρών ενεργειακών αγαθών σε παγκόσμιο επίπεδο. Συγκεκριμένα, εξετάζονται τα παγκόσμια αποθέματα πετρελαίου και φυσικού αερίου, η κατανομή και εξέλιξή τους την τελευταία δεκαετία. Αναφέρονται παράγοντες που επηρεάζουν την μεταβλητότητα των τιμών πετρελαίου και φυσικού αερίου και οι δείκτες αναφοράς που χρησιμοποιούνται στην “spot” αγορά. Επίσης, αναλύεται η παγκόσμια προσφορά και ζήτηση των αγορών πετρελαίου και φυσικού αερίου και ειδικότερα του υγροποιημένου φυσικού αερίου (ΥΦΑ). Όσων αφορά την παραγωγή, αναλύεται η δυναμική των αγορών πετρελαίου και φυσικού αερίου από την πλευρά της προσφοράς σε παγκόσμιο επίπεδο, λαμβάνοντας υπόψη τις τιμές πετρελαίου, φυσικού αερίου και ΥΦΑ, την παραγωγή πετρελαίου και φυσικού αερίου, τις μεγαλύτερες εξαγωγικές χώρες και το εμπόριο. Αναφέρεται επίσης ο ρόλος που παίζουν οι χώρες του ΟΠΕΚ και οι εθνικές εταιρείες πετρελαίου και φυσικού αερίου. Αναφέρεται στο φαινόμενο της «κατάρας των πόρων» από το οποίο υποφέρουν πολλές μεγάλες χώρες εξαγωγής πετρελαίου και σε γεωπολιτικά θέματα που αφορούν το φυσικό αέριο. Όσων αφορά την ζήτηση, εντοπίζονται οι τομείς με τη μεγαλύτερη ζήτηση πετρελαίου και φυσικού αερίου τα τελευταία χρόνια και οι παράγοντες που επηρεάζουν την πρωτογενή ενεργειακή κατανάλωση παγκοσμίως. Καταλήγει στον εντοπισμό τάσεων στην παγκόσμια προσφορά και την ζήτηση την τελευταία δεκαετία και σε προβλέψεις μεσοπρόθεσμα και μακροπρόθεσμα. Η δεύτερη ενότητα αναλύει τις θαλάσσιες μεταφορές υγρών ενεργειακών αγαθών και το διεθνές μεταφορικό σύστημά τους. Πρώτα, αναλύεται η παγκόσμια αγορά των δεξαμενοπλοίων που μεταφέρουν αργό πετρέλαιο και παράγωγά του, υγροποιημένο φυσικό αέριο και υγραέριο καθώς επίσης και πρόσφατες εξελίξεις όσων αφορά την ζήτηση και την προσφορά του στόλου. Γίνεται μια σύντομη περιγραφή των συνθηκών ανταγωνισμού αυτών των αγορών και αναφέρονται οι κύριοι ανταγωνιστές παγκοσμίως. Αναφέρονται απόψεις σχετικά με τη μέλλουσα κατάσταση των αγορών αυτών μεσοπρόθεσμα. Έπειτα, αναλύεται η διαμόρφωση της τιμής θαλάσσιας μεταφοράς, γίνεται σύγκριση στα μεταφορικά κόστη πετρελαίου και σύγκριση στα μεταφορικά κόστη φυσικού αερίου μέσω αγωγών έναντι των πλοίων. Στο τέλος της ενότητας, εντοπίζονται οι κύριοι λιμένες, οι διεθνείς μεταφορικές οδοί και οι εμπορικές ροές των ενεργειακών αυτών εμπορευμάτων. Η τρίτη ενότητα αφορά το σύγχρονο θεσμικό πλαίσιο που διέπει τις θαλάσσιες μεταφορές υγρών ενεργειακών αγαθών καθώς επίσης και πρόσφατες εξελίξεις. Συγκεκριμένα, αναφέρεται στο ισχύον πλαίσιο όπως έχει ορίσει ο Διεθνής Ναυτιλιακός Οργανισμός (IMO), στο ευρωπαϊκό πλαίσιο, πολιτικές της Ευρωπαϊκής Ένωσης για τη ναυτιλία και στο ελληνικό θεσμικό πλαίσιο. Η τέταρτη ενότητα αναλύει τους προσδιοριστικούς παράγοντες που επηρεάζουν την διεθνή αγορά υγρών ενεργειακών αγαθών από την πλευρά της ζήτησης και της προσφοράς. Στη συνέχεια, εξετάζεται πως η ενεργειακή αγορά επηρεάζει την αγορά θαλάσσιων μεταφορών αναλύοντας δεδομένα τριών μεταβλητών: την παγκόσμια ετήσια παραγωγή, την τιμή των αγαθών και την τιμή των ναύλων. Η πέμπτη ενότητα αναλύει τις τάσεις και τις προοπτικές των δυο αγορών και συμπεραίνει.

Adaptive Regenerative Braking in Electric Vehicles

Scipedia content — Tue, 26 Jan 2021 14:05:13 +0100

Elektrofahrzeuge fahren lokal emissionsfrei und tragen damit dazu bei, die Emissionen in Städten zu reduzieren. Zusätzlich, zeichnen sich Elektrofahrzeuge durch ein dynamisches Fahrverhalten aus. Nachteilig wirkt sich bei den meisten Elektrofahrzeugen, die geringe Reichweite auf die Akzeptanz bei Neuwagenkäufern aus. Eine der Maßnahmen zur Erhöhung der Reichweite von Elektrofahrzeuge ist das regenerative Bremsen. Hierbei wird die kinetische Energie des Fahrzeugs durch generatorisches Bremsen als elektrische Energie zurückgewonnen. Diese zurückgewonnene Energie erhöht die Reichweite des Autos. In dieser Dissertation, wird ein adaptives regeneratives Bremssystem vorgestellt. Dieses System wählt abhängig vom Fahrertyp und der aktuellen Verkehrssituation ein geeignetes regeneratives Bremsniveau aus. Um ein solches System zu realisieren, wurden Verfahren entwickelt, welche einerseits den Fahrertyp und andererseits die Fahrerintention durch Analyse des Fahrbetriebs ermitteln. Dazu wurde u.a. ein mehrdimensionales verstecktes Markov-Modell (MDHMM) entwickelt. Bei Verwendung des Fahrertyps und der Intention des Fahrers, kann so eine geeignete Bremsstufe ausgewählt werden, die die physikalische Begrenzung der Fahrzeugkomponenten berücksichtigt. Durch den Einsatz des entwickelten Systems, kann gezeigt werden, dass eine Erhöhung der Reichweite erreicht werden kann, ohne den Komfort des Fahrers zu beeinträchtigen.

The influence of content marketing initiatives on professionals’ engagement : the case of self-driving cars

Scipedia content — Tue, 26 Jan 2021 14:02:38 +0100

utomated driving depicts a disruptive technology in the automotive sector. LinkedIn (LI) constitutes herby the social media platform, which connects experts from all over the globe. Experts are active via the LinkedIn feed and within expert groups, however, engagement with the content can be described as low. This thesis aims to investigate this issue, by analysing factors which lead to engagement with Content Marketing initiatives amongst professionals on LI. Engagement factors are divided into the four categories: motivational factors to engage (1), measured with Baldus’ et al. (2014) scale, characteristics of a post (2), the influence of the topic (3) and the format (4) on engagement. Those factors are examined within three subgroups, users solely reading the headlines (1), users consuming the content (2) and users engaging with the content (3). A survey administered on LinkedIn leads to the findings, that professionals are predominantly interested in pure exchange of high quality information and that the engagement increases with the time the professional is in the field and with proximity to the actual research. Those users are best targeted in LI groups. Societal topics, such as ethics have a subordinate effect on engagement. Previous interactions (likes, comments and shares) with the content do not have an impact on the user’s engagement. Professionals utilize a diverse plethora of knowledge sources, where LI constitutes a supplementary online source, which can easily be exchanged. Therefore, the marketer has the obligation to provide timely and relevant content in order to avoid redundancy and stay competitive.

The influence of the diesel scandal on traditional car manufacturers electric vehicle development as part of the automotive megatrends

Scipedia content — Tue, 26 Jan 2021 14:00:55 +0100

The automotive industry currently faces four megatrends which are challenging the competitive environment: Connectivity, Autonomous Driving, Shared Services and Electric Vehicles. On top of that, aftermaths from the Diesel scandal are still noticeable. Therefore, the objective of this work was to find whether the Diesel scandal has an influence on the development of Electric Vehicles of traditional car manufacturers among the other trends. First, consumers were asked to fill out a survey on the attractiveness of and their attention to-wards Electric Vehicles before and after the scandal. It was concluded that EV demand didn’t change because of the Diesel scandal, even though the attention of consumers increased. A main reason therefore is the dependency of EV demand on financial incentives rather than en-vironmental concerns. Second, to measure the impact on EV development, selected employees from traditional car manufacturers were interviewed and the results were discussed with an industry expert. After collecting the drivers behind Electric Vehicle development, an indirect influence on EV devel-opment was revealed. To meet environmental targets set by governments or political unions, OEMs must focus on new technologies due to the lack of Diesel car sales. When establishing a connection between the research findings and literature, the dynamic ca-pabilities framework was not found to be applicable as the development and adaptation of Elec-tric Vehicles is mainly dependent from external surroundings. Thus, Industrial Organization as underlying theory was found to be suitable. A indústria automóvel enfrenta atualmente quatro macrotendências que desafiam a envolvente competitiva: Conectividade, Direção Autónoma, Serviços Partilhados e Veículos Elétricos. Além disso, os resultados do escândalo “Diesel” ainda são visíveis. O objetivo deste trabalho foi descobrir se o escândalo “Diesel” tem influência no desenvolvimento de veículos eléctricos de fabricantes dentro da indústria tradicional automóvel, entre outras tendências. Em primeiro lugar, foi pedido aos consumidores que preenchessem um questionário sobre a atratividade e a atenção destes para com os veículos elétricos antes e depois do escândalo. Concluiu-se que a procura de veículos elétricos não mudou devido ao escândalo “Diesel”, embora a atenção dos consumidores tenha aumentado. Uma das principais razões, portanto, é a dependência de veículos elétricos de incentivos financeiros, em vez de preocupações ambientais. Em segundo lugar, para medir o impacto no desenvolvimento de veículos elétricos, foram entrevistados funcionários, seleccionados de fabricantes de automóveis tradicionais, e os resultados foram discutidos com um especialista do setor. Depois de recolher os drivers por detrás do desenvolvimento do Veículo Elétrico, uma influência indireta no desenvolvimento de VE foi revelada. Para atingir as metas ambientais estabelecidas pelos governos ou sindicatos políticos, os OEMs devem-se focar em novas tecnologias devido à falta de vendas de carros a “Diesel”. Ao estabelecer uma conexão entre os resultados da pesquisa e a literatura, a tese das capacidades dinâmicas não se mostrou aplicável ao desenvolvimento e adaptação de veículos elétricos. Assim, a Organização Industrial como teoria subjacente foi considerada adequada.

Dealing with diversity: Challenges and opportunities for social cohesion in deprived neighbourhoods

Scipedia content — Tue, 26 Jan 2021 13:56:29 +0100

Policy makers worry about the negative impact of the concentration of disadvantaged groups and minority ethnic groups on social cohesion in deprived neighbourhoods. A popular response has been to diversify the housing stock as to house more households with a higher socioeconomic position, which in practice are mostly white Dutch. A large body of research has assessed these interventions and has not found clear evidence for the intended results: when it comes to local social networks, lower and higher income groups and ethnic communities are often found to live parallel lives. However, the recent academic literature on super-diversity and hyper-diversity suggests that these studies might not grasp the full picture: urban societies are becoming diverse in ever more complex ways, not only in terms of ethnicity and class, but also regarding activity patterns, households types, cultures, lifestyles and identities. There is an increase in diversity within traditional demographic categories as well. This poses important challenges for conducting research, particularly research on social perceptions and relations. Scholars have only recently started to study what complex urban diversity means for questions of social cohesion. Much remains unclear about how people in highly diverse neighbourhoods perceive, experience and practice local diversity. This study attempts to provide insight. It examines how residents of deprived neighbourhoods face the challenges of living among diverse others and how they seize the opportunities for positive relations across differences. The study does not focus on ethnic and income diversity a priori. Rather, it adopts a comprehensive approach to diversity. The research results refute the dominant understanding in academia and policy that diverse deprived areas lack social cohesion.

Barriers and Best Practices to the Use of Public Transportation: A Case Study of the South Baltic Sea Region

Scipedia content — Tue, 26 Jan 2021 13:55:13 +0100

Climate change is a pressing issue caused by the systematic increase of greenhouse gasses (GHG). One way to avoid higher GHG emissions is through an increased use of public transportation, transitioning society away from the personal automobile. Public transportation is more sustainable than the personal automobile as its emissions per person are less and it takes up significantly less space. Sustainability is defined through the principle-based definition of the Framework for Strategic Sustainable Development (FSSD). This research studied barriers and best practices to the use of public transportation in the South Baltic Sea Region (SBSR), in cooperation with the EU funded InterConnect Project. The research team was able to use the resources of the InterConnect Project for their methods in order to discover perceived barriers and potential best practices and ideas to overcome these barriers through the stakeholder perspective. The research team concludes that by addressing the perceived barriers, a first step towards transitioning society within the SBSR towards more sustainable transportation can be done. As transportation is complex and connected to other systems, the need for a systems perspective and a strategic and collaborative approach was identified. This could be achieved through using the FSSD in the SBSR.

Controlling the distributed energy resources using smart grid communication technologies

Scipedia content — Tue, 26 Jan 2021 13:54:02 +0100

In recent years, consumer demand, energy consumption rates, and control requirements have increased. This necessitates the control of electrical systems remotely with communication system by advanced technologies which have distributed energy resources. Therefore, transforming the existing electrical grid into the smart grid requires remote control for the development of more efficient, more convenient and more reliable systems and its structures are being researched. In this thesis, communication structures used in control requirements and integration of renewable electrical sources are examined. Then, micro grid system model is designed which is used with power line communication infrastructure, distributed energy resources, and electric vehicles system and the overall system is simulated by Matlab Simulink. Photovoltaics technology is integrated as distributed resources and the simulation results are examined for the quality of transmitted energy in different situations of the micro grid. Besides, the applicability of the distributed resources considering power quality is observed when placed near to non-linear load buses. At the same time, the increased power of distributed resources has improved both the system's voltage and its power quality indices.

Guideline for an installation of a charging infrastructure for electric vehicles in Beijing

Scipedia content — Tue, 26 Jan 2021 13:50:34 +0100

Die Arbeit beschäftigt sich mit der Untersuchung von Einflussfaktoren auf eine Ladeinfrastruktur von Elektrofahrzeugen in Peking. Neben den politischen, technischen und wirtschaftlichen Faktoren, liegt der Fokus auf einer Analyse von Nutzerdaten und einer räumlichen Auswertung der Wohn- und Parkplatzsituationen in Peking in Bezug auf die Errichtung einer Ladeinfrastruktur für Elektrofahrzeuge. Der Hauptteil der Arbeit analysiert die städtebauliche Struktur Pekings und kombiniert diese Erkenntnisse mit der Analyse von realen Fahrprofilen von Elektrofahrzeugen. Auf Grund der geringen Anzahl von Parkplätzen sowohl im öffentlichen Raum als auch in den geschlossenen Wohnsiedlungen (Compounds), gestaltet sich die Installation von Ladesäulen, an denen EVs mehrere Stunden laden müssen, als schwierig. Dies betrifft sowohl poly-zentrische als auch mono-zentrische Stadtbezirke im Zentrum. Die Analyse der Fahrprofile basiert auf einem zweiwöchigen Zeitraum mit 60 E-Fahrzeugen, die von Nutzern in Peking gefahren wurden. Ladevorgänge fanden circa 2-3 mal die Woche statt, fanden auf privat Grundstücken statt und dauerten meistens über 10 Stunden. Auf Grund der aufgenommenen GPS-Daten konnte der genaue Aufenthaltsort der Park- und Ladevorgänge untersucht werden. Dabei zeigte sich, dass Fahrzeugführer immer nachts an denselben Orten parkten und luden. Mit den gewonnen Daten konnte auch festgestellt werden, dass home-charging, also das Laden daheim, für die aller meisten Fahrten gänzlich ausreicht. Ergänzt werden kann es durch destination-charging, dem Laden am Zielort, oder on-the-go-charging, dem Laden auf dem Weg zum Zielort. Dabei sind die beiden letzteren Optionen in Peking im halb-öffentlichen Raum anzuordnen, weil reines, öffentliches Laden an Straßenrändern oder Parkplätzen auf Grund von mangelndem Platz nicht möglich sind. The dissertation deals with the analysis of factors of influence on an implementation of a charging infrastructure for electric vehicles in Beijing. Next to the political, technical and economic factors, the focus is on an analysis of user data and on a spatial analysis of residential housing and parking situations in Beijing. All analyses were done in relation to the implementation of a charging infrastructure for electric vehicles. The main part of the work analyzes the urban structure of Beijing and combines its findings with the analysis of driving profiles of electric vehicles. Due to the small number of parking spaces in public spaces as well as in closed housing estates, the installation of charging stations, becomes a challenge. This concerns both poly-centric and mono-centric city districts in the center of the city. This applies especially to compounds from the 1960s to 1980s, because they were built without adequate parking lots in those days. These properties cannot accommodate the current number of vehicles by far, resulting in the fact that public and semi-public space for parking has to be used. An analysis of the driving profiles is based on a two-week period with 60 electric vehicles driven by real users in Beijing. The investigated vehicles could be charged with alternating current, which prolongs the charging time compared with direct current charging considerably. It was found that most of the parking events took place with relatively full batteries and the distances could be overcome by a single battery charge. Due to the recorded GPS data, the exact location of the parking and charging events could be examined. It was found that EV drivers always parked and charged at night at the same locations. Furthermore it was discovered that home-charging is sufficient for most tracks of the user. This charging type can be extended by destination-charging, or on-the-go-charging.

Essays on Delay Reduction Contract, Airline Networks and Agricultural Land Marketization

Scipedia content — Tue, 26 Jan 2021 13:43:43 +0100

Cette thèse se compose de trois articles autonomes, dont chacun correspond à un chapitre. Le premier chapitre, écrit conjointement avec Estelle Malavolti, étudie la conception optimale du contrat de réduction des retards signé entre un ANSP et une compagnie aérienne monopoliste. Dans la conception du contrat, nous considérons principalement le problème d’antisélection. En outre, nous effectuons une analyse comparatif-statique pour étudier les effets de la norme de sécurité et de la fréquence de vol sur les contrats optimaux. A la fin, nous utilisons des exemples numériques pour étudier le cas où un ANSP maximisant son bien-être doit utiliser des fonds publics pour fournir le service. Le deuxième chapitre étudie le double rôle des retards de congestion et de la différenciation horizontale des produits dans le choix du réseau aérien. Je trouve que, premièrement, en raison de l’inclusion des retards de congestion, la compagnie aérienne peut choisir le réseau point à point lorsque la désutilité des services avec une escale, engendrée par le temps supplémentaire du voyage, est relativement faible. Deuxièmement, sans tenir compte des investissements fixes de la compagnie aérienne dans le développement d’un aéroport de hub, le réseau 2-hub dominera les trois autres structures de réseau aussi longtemps que cela sera possible, car il implique la différenciation horizontale des produits sur plus de marchés que les trois autres structures de réseau. Le troisième chapitre, écrit conjointement avec Wanjun Yao et Shigeyuki Hamori, trouve empiriquement que l’efficacité de l’allocation des terres plus élevée améliore la productivité des terres moyenne de 29,1% et la plus grande taille de la ferme opérationnelle moyenne réduit la productivité des terres moyenne de 9,2%, ce qui implique que la commercialisation des terres agricoles en Chine améliore finalement la productivité des terres moyenne de 19,9%.

The potential for a transport mode shift to improve the sustainability of travel in the suburbs of Adelaide, South Australia /

Scipedia content — Tue, 26 Jan 2021 13:35:05 +0100

Thesis (Masters by research(Civil Engineering))--University of South Australia, 2018. Includes bibliographical references (pages 73-75) Moving people around in cars accounts for 8.3% of Australian carbon emissions. According to the Australian climate council, these transport emissions are Australia’s fastest growing emissions source. Currently, 86% of the Australian population lives in a suburban landscape, concentrating car use, and the associated carbon emissions. The way forward for environmentally sustainable vehicular transport is to electrify vehicles. It will be difficult and slow to get individual owners to electrify their vehicles, so the current individual ownership model needs to be reduced in favour of utilising vehicle fleets. Public transport bodies already have a vehicle fleet that is underutilised and are investing in low carbon solutions. Access to and competitiveness of these public transport services when compared to car options are significant barriers to shifting large proportions of travellers to this mode. This study aimed to understand the transport priorities of suburban residents in order to further understand how to improve the sustainability of travel.

Design of an electric tilting quad bike

Scipedia content — Tue, 26 Jan 2021 13:33:16 +0100

Outgoing

Train Induced Vibration Analysis of an End-frame Bridge : Numerical Analysis on Sidensjövägen

Scipedia content — Tue, 26 Jan 2021 13:32:07 +0100

Higher speeds and higher capacity will cause the Swedish rail network to be exposed to disturbing dynamic effects. Higher speeds cause higher vertical acceleration levels of the bridge deck. In this thesis, a numerical analysis of a three span end-frame bridge subjected to train induced vibrations is performed. The aim is to identify which structural components and boundary conditions that affect the dynamic behavior of the bridge. Furthermore, the influence of soil structure interaction (SSI) will be investigated as it may have contribution to the stiffness and damping of the structural system. In order to capture the dynamic response of the bridge, an analysis in the frequency domain was preformed where frequency response functions (FRF) and acceleration envelopes were obtained. For this purpose, a detailed FE-model in 3D was created. Three different cases were studied, model subjected to ballast, model subjected to soil and model subjected to both ballast and soil in coherence. A high speed load model (HSLM) was used to create simulation of train passages at different speeds and applied to all cases so that the bridge deck accelerations could be studied. A simplified 2D-model with impedance functions representing the soil-structure interaction was created to validate the results from the detailed 3D-model and for practical design purposes. The result of this numerical analysis showed that the vertical accelerations were within acceptable levels of the maximum allowed limits given in governing publications. Considering the surrounding soil, the results revealed an increase of the dynamic response in the midspan at resonant frequency. However, it was identified that this behavior is not explained by the influence of soil structure interaction but rather the change in boundary conditions of the end-shields. The same dynamic behavior was identified for the simplified 2D-model, with a slight underestimation of the vertical accelerations at resonance.

Flambagem vertical de dutos desencadeada pela pressão interna resultante do transporte de petróleo e gás natural: discussões teóricas e análise geometricamente não linear usando o Método dos Elementos Finitos.

Scipedia content — Tue, 26 Jan 2021 13:30:54 +0100

The pipelines used to transport oil and gas from the wellheads to the distribution and refining sites can be subjected to high levels of pressure and temperature. Under such conditions, the pipelines tend to expand, but, if the expansion is inhibited, a significant compressive axial force can arise, leading to their buckling, which can occur in the horizontal or vertical plane. In this context, the objective of the present work is to analyze the upheaval buckling of pipelines, considering the internal pressure to which they are subjected during the transportation of oil and gas as its only triggering. Using the concept of effective axial force, it aims at discussing two different approaches for considering the internal pressure in buckling problems: distributed loads dependent on pipeline curvature and equivalent compressive axial forces with follower and non-follower characteristics. It also discusses the influence of using static or dynamic analysis for such approaches. Concerning the upheaval buckling itself, the work intends to analyze and compare the influence of the soil imperfection amplitudes to the influence of the friction between the pipeline and the ground in the critical loads and in the post-buckling configurations of the pipeline. Besides theoretical research, the objectives are achieved through the development of various numerical models, since geometrically-simple models, without the consideration of the interaction between the pipeline and the ground, until more complex models, with the use of contact models to detect the ground and its imperfections. The models are developed in Giraffe (Generic Interface Readily Accessible for Finite Elements) using geometrically-exact finite element models of beams, undergoing large displacements and finite rotations. Through the research, it is concluded that there is an equivalence between the application of the internal pressure as a distributed load dependent on pipeline curvature and the application of the internal pressure as a follower compressive axial force. Besides this, it is demonstrated that the type of the analysis (static or dynamic) depends on the nature of the physical system analyzed. With the aid of results presented in terms of internal pressure, classical results about the influence of the imperfection amplitudes and of the friction between the pipeline and the ground in buckling are confirmed. It is also showed that the imperfection amplitudes analyzed play a more important role in the post-buckling configurations of the pipeline than the friction. Os dutos utilizados para transportar petróleo e gás natural das reservas até os locais de distribuição e refino podem estar submetidos a elevados níveis de pressão e temperatura. Sob tais condições, os dutos tendem a se expandir, porém, se a expansão é inibida, uma força axial de compressão significativa pode surgir nos dutos, ocasionando a flambagem lateral ou vertical dos mesmos. Dentro desse contexto, o objetivo do presente trabalho é analisar a flambagem vertical de dutos, considerando a pressão interna à qual eles estão submetidos durante o transporte de petróleo e gás natural como o único parâmetro desencadeador da flambagem. Usando o conceito de força axial efetiva, o trabalho objetiva discutir duas abordagens diferentes para considerar a pressão interna nos problemas de flambagem: carregamentos distribuídos dependentes da curvatura do duto e forças axiais de compressão equivalentes à pressão com caráter seguidor e não seguidor. O trabalho também discute a influência de usar a análise estática ou dinâmica para analisar essas abordagens de carregamento. Com relação à flambagem vertical propriamente dita, o trabalho pretende analisar e comparar a influência das amplitudes das imperfeições presentes no solo com a influência do atrito entre o duto e o solo nas cargas críticas e nas configuração pós-críticas do duto. Além de pesquisa teórica, os objetivos são atingidos através do desenvolvimento de vários modelos numéricos, desde modelos geometricamente simples, sem a consideração da interação entre o duto e o solo, até modelos mais complexos, com o uso de modelos de contato para detectar o solo e suas imperfeições. Os modelos são desenvolvidos no Giraffe (Generic Interface Readily Accessible for Finite Elements) usando elementos finitos geometricamente exatos de viga, sujeitos a grandes deslocamentos e rotações finitas. Através da pesquisa, conclui-se que existe uma equivalência entre a aplicação da pressão interna como um carregamento distribuído dependente da curvatura do duto e a aplicação da pressão interna como uma força axial de compressão seguidora. Além disso, demonstra-se que o tipo de análise (estática e dinâmica) depende da natureza do sistema físico analisado. Com a ajuda de resultados apresentados em termos de pressão interna, os resultados clássicos sobre a influência das amplitudes das imperfeições e do atrito entre o duto e o solo são confirmados. Também é mostrado que as amplitudes das imperfeições analisadas desempenham uma maior influência nas configurações pós-críticas do duto do que o atrito.

Efectos del desarrollo tecnológico de las baterías en el sistema interconectado nacional de Colombia

Scipedia content — Tue, 26 Jan 2021 13:27:49 +0100

La creciente preocupación por el deterioro del medio ambiente ha llevado al desarrollo de nuevas tecnologías para el almacenamiento de energía eléctrica. Lo anterior como alternativa para afrontar el desafío que constituye tener sistemas eléctricos energéticamente sostenibles y que a su vez garanticen seguridad de suministro. Todo este desarrollo potencia la inclusión de vehículos eléctricos y la generación de energía a partir de fuentes renovables, sin embargo, esto también provoca cambios en el estado actual del mercado eléctrico. Estos cambios pueden originar un problema de incertidumbre sobre los efectos que se producen en la curva de carga, debido principalmente a la alta demanda eléctrica por la recarga de las baterías de un gran número de vehículos y por permitir una mayor participación de autogeneración. Con el objetivo de preparar el sistema eléctrico para enfrentar dichos cambios, es necesario implementar herramientas como los modelos, que permitan identificar las ventajas e inconvenientes que se pueden presentar. En esta tesis se expone un modelo de simulación para identificar y evaluar los efectos en la curva de carga a partir de dos variables clave. La primera, el porcentaje de penetración tanto de vehículos eléctricos como de micro generación con paneles solares. La segunda, la hora en la que se realiza la recarga de las baterías. Este modelo permite analizar la interacción entre la oferta y la demanda de energía cuando entran en el Sistema Interconectado Nacional las tecnologías ya mencionadas. Los resultados encontrados muestran que, en ausencia de políticas energéticas, una gran penetración de vehículos eléctricos y de sistemas fotovoltaicos para autogeneración podría afectar la estabilidad de la fuente de alimentación. Lo anterior evidencia la importancia de construir un plan que prepare al mercado eléctrico para soportar la entrada de nuevas tecnologías, dado que los efectos en la red varían de acuerdo a las estrategias definidas por el gobierno Abstract: The growing concern about the environmental degradation has led to the development of new technologies for electrical energy storage as an alternative to face the challenge of having energy -efficient electrical systems that ensure security of supply. This development enhances the inclusion of electric vehicles and the generation of energy from renewable sources, but also makes changes in the current state of the electricity market. The changes can lead to the generation of uncertainty problems in the effect s on the load curve due to a high electricity demand when batteries from a large number of vehicles are recharged and to a greater participation in auto - generation. In order to prepare the Electricity System to face the changes, we require to establish a m odel that allows it to determine the effect on the load curve due to the emerging electrical technologies. In this thesis, we present a simulation model for the identification and evaluation of the effects on the load curve from two key variables. The first variable is the percentage of penetration of both electric and micro - generation vehicles with solar panels; The second variable is the moment at which the batteries are recharged. This model allows analyzing the interaction between the supply and the demand of energy when the technologies already mentioned enter into the national power grid . The results show that, in the absence of energy policies, a large penetration of electric vehicles and photo -voltaic systems for auto -generation could affect the stability of the power supplies. This shows the importance of constructing a plan that prepares the electric market to support the emerging technologies, since the effects on the network vary according to the strategies defined by the government.

Integrating electric vehicles as load in unit commitment

Scipedia content — Tue, 26 Jan 2021 13:25:28 +0100

During the last few years’ electric vehicles started to catch more attention. According to environmental policies of major states and unions of states, the number of electric vehicles will be increasing in the next years. In this thesis is studied the problem of unit commitment with high penetration of renewable sources, by presenting different methods for forecasting the renewable production. Furthermore, a model of a flexible load from electric vehicles is integrated into the unit commitment models. The aim of this research is to study the impact of the excessive load on the production side and compare different unit commitment models. It is demonstrated that optimized charging is cheaper than random charging for all the models and allows higher numbers of electric vehicles to be integrated into the electric system. Simulations showed that the cost of energy increased slightly by 1% for the optimized charging profile when using 100% electric vehicles penetration, whereas in the random charging profile the increase was around 15% for the same percentage of electric vehicles penetration.

The Value of Urban Density

Scipedia content — Tue, 26 Jan 2021 13:25:10 +0100

This article-based doctoral thesis addresses the following question: What are the main drivers and barriers of urban densification as planning strategy in the quest for more sustainable cities in Norway? The research uses a mixed-method approach to explore specific aspects of the densification process. One such aspect is the practicability of making denser the sprawling Norwegian cities, and the effects that such gains in density imply for transport, one of the most significant aspects of sustainability. Another aspect investigated is the issue of social acceptability using land prices as a proxy. The analysis, based on a hedonic pricing model for Trondheim, indicates a tendency towards higher prices of dwellings per square metre in denser locations, although some aspects of density seem to produce a contrary effect. The research also delivers a systemic overview of the actors and factors shaping urban development. This analysis applies a multilevel-perspective approach used in sustainability transition studies to study the main factors and actors behind urban densification in Trondheim. Resulting data indicate that despite a strong emphasis in planning towards sustainability, practices behind urban development have not changed much. As an answer to the main question posed above, the main drivers and barriers of urban densification in Norway are as follows. The environmental: Global environmental concerns have driven the adoption of national and local policies towards greater efficiency in the use of natural resources and a decrease in pollution. Urban densification is regarded as an important means to achieve these targets. The most important environmental barrier is the pre-existence of a scattered urban layout, fragmented in the rugged Norwegian geography, which makes it difficult to increase urban density and make substantial gains from recent changes in policy. The social: Demographic changes have facilitated the application of densification policies but entrenched social values, such as freedom of choice, make it difficult to apply restrictive measures, such as urban containment or car-usage restrictions. The economic: Changes towards a knowledge-based economy imply multiple benefits from larger, more intense urban environments; but given the pre-existence of a large sprawled urban form, the sunk investments in infrastructure make it difficult to accelerate urban changes towards denser urban environments. The institutional: The discourse on sustainability has gained strength at almost all institutional levels. However, to a large extent legal frameworks and procedural traditions remain unchanged.

Real Time Voltage and Thermal Management of Low Voltage Distribution Networks through Plug-in Electric Vehicles

Scipedia content — Tue, 26 Jan 2021 13:22:03 +0100

Peak oil, climate change and the achievement of energy independence have set the world into a new energy transition seeking to decarbonize both the power generation and transportation sectors. The convergence and synergy between both sectors, an electrified transportation powered by renewable energy, holds true potential to significantly reduce the world’s dependence on fossil fuels and the consequent emission of greenhouse gases. Nonetheless the integration of electric vehicles on the power system is not a minor issue and its associated impacts need to be carefully analyzed and addressed. In this context the main objective of this thesis is to develop a smart charging solution to safely integrate Plug-in Electric Vehicles into low voltage distribution networks while mitigating their corresponding impacts. This is done by designing a control algorithm capable to simultaneously meet both voltage and thermal network constrains by managing the vehicle’s charging process in real-time, while at the same time being respectful to current charging standards, computationally light and implementable in any current radial distribution grid. The proposed charging algorithm is built under a “Multi-Agent System” architecture combining a local decentralized voltage management with a centralized thermal control conceived to minimize user impact under three alternative optimization techniques. The architecture is fully implemented and tested on a realistic environment using Simulink by modeling key elements such as the charging stations, the vehicles themselves, and the different dwellings. An extensive analysis of the algorithm’s performance is completed testing it under multiple relevant scenarios. Finally the control algorithm is transferred to a real-time simulator (dSPACE MicroLabBox) to be validated and further evaluate its behavior through hardware-in-the-loop (HIL) simulations using both real charging stations and Plug-in Electric Vehicles available in the laboratory A satisfactory validation of the algorithm’s execution under and compatibility with real hardware is revealed by the HIL tests. At the same time a successful management of the considered network voltage and thermal constrains is obtained under all implementations, causing a minimal impact over the participating users and effectively peak shaving their total aggregated demand. For a full vehicle penetration scenario, the proposed control successfully prevents over 200 voltage limit violations and achieves so while significantly reducing the total transformer loading deviation, almost halving it when compared to an equivalent unrestricted charging case, and ensuring a net zero impact to 95% of participating users under its most effective thermal implementation. The study also reveals that a full participation of all vehicle owners is not critical factor to ensure a proper grid operation under the designed algorithm, as satisfactory results are also obtained when only half of them are actively involved in network management. Finally an economic assessment covering the application of the designed control over conventional network reinforcements further demonstrates the advantages of such an active management approach reporting additional economic benefits to the DSO.

Analysis of typical traffic networks

Scipedia content — Tue, 26 Jan 2021 13:20:07 +0100

Real time detection of traffic signs using onboard vehicular cameras

Scipedia content — Tue, 26 Jan 2021 13:19:38 +0100

aplicação de novas tecnologias tem afetado profundamente a indústria automobilística, especialmente quando se fala de carros autônomos. O cenário de auto-condução está próximo de se tornar realidade, entretanto, muitos desafios ainda precisam ser resolvidos. Outro aspecto que está motivando os avanços tecnológicos é a necessidade pelo aumento da segurança, no qual grande parte do esforço está sendo feito para reduzir o número de acidentes de trânsito, especialmente aqueles causados por erro do motorista. A redução de acidentes traz como conseqüência, uma diminuição nas mortes, lesões e nos custos financeiros associados aos acidentes. Dentro desse contexto, esta dissertação apresenta uma abordagem para detecção e reconhecimento de sinais de trânsito usando câmeras veiculares a bordo. Assumindo que os parâmetros intrínsecos da câmera são obtidos off-line, um esquema de calibração on-line é usado para estimar os parâmetros da câmera extrínseca, e as Regiões de Interesse (ROIs) são criadas no domínio da imagem com base na geometria e localização esperadas dos sinais de trânsito. Dado o tamanho reduzido e a complexidade de fundo desses ROIs, desenvolvemos uma Rede Neural Convolucional Regional (CNN), chamada ScapNet. Nossos resultados experimentais para os sinais de trânsito brasileiros indicam que a abordagem proposta apresenta uma precisão de classificação comparável a métodos de última geração em tempos de funcionamento muito mais rápidos. The application of new technologies has been profoundly affecting the automobile industry, especially when talking about autonomous cars. The self-driving scenario is close to becoming reality, however many challenges still need to be solved for this. Another aspect that is motivating the technological advances is the need to increase safety, in which much of the effort is being made to reduce the number of traffic accidents, especially those caused by driver errors. The reduction of accidents brings as a consequence a decrease in the resulting injuries and fatalities, as well as the related financial costs. Within this context, this thesis presents an approach for traffic sign detection and recognition using off-the-shelf onboard vehicular cameras. Assuming that the camera intrinsic parameters are obtained off-line, an on-line calibration scheme is used to estimate the extrinsic camera parameters, and Regions of Interest (ROIs) are created in the image domain based on the expected geometry and location of the traffic signs. Given the reduced size and background complexity of these ROIs, we developed a lightweight regional Convolutional Neural Network (CNN), called ScapNet. Our experimental results for Brazilian traffic signs indicate that the proposed approach presents classification accuracy comparable to state-of-the-art methods at much faster running times, with over 30 FPS on embedded devices.

Violência, percepção de segurança e escolha modal em viagens a um campus universitário

Scipedia content — Tue, 26 Jan 2021 13:18:43 +0100

This dissertation addresses the validation of the hypothesis there is a general sense that violence and security perception influence the use of sustainable travel modes. The research characterizes the issue of security perception among University of São Paulo (Brazil) users and identifies the way the sense of security and violence occurrences are related to the travel mode choice. An online survey on security perception and the way its participants access the campus was conducted. The target relationships were explored by Decision Tree (DT) algorithms. An initial exploratory analysis revealed occurrences of violence and reports of insecurity perception were strongly correlated on streets around the campus. The time analysis of violence distribution presented the incidents concentrated at night and during the week. The study also showed that security perception variation according to gender and travel mode choice is less sensitive to security perception than to the occurrence of violence, or type of affiliation to the university. Finally, DT algorithms explored the relation of spatially treated variables (i.e. route length to the university, density of violence occurrences and insecurity reports on the route) to mode choice. The results also showed that distance to the campus was relevant to the mode choice only in routes not strongly considered unsafe. In routes of higher insecurity perception, the share of nonmotorized modes was more expressive and the largest participation of sustainable modes was on routes with high incidence of violence. Since it is counterintuitive to assume numerous walking trips are a consequence of violence, the opposite was considered as a possible explanation to those results. The present study reinforces the need for increased surveillance in regions with high participation of non-motorized modes, for preventing users from shifting to motorized modes. Esta dissertação busca comprovar a hipótese de que a violência e a percepção de segurança influenciam o uso de modos de transporte sustentáveis. A pesquisa caracteriza a questão da percepção de segurança entre os usuários da Universidade de São Paulo (Brasil), em São Carlos, e identifica como o sentimento de segurança pessoal e a violência estão relacionados com a escolha do modo de viagem. Foi realizada uma pesquisa on-line sobre a percepção de segurança dos usuários da universidade e a forma como eles acessam o campus. As interações foram exploradas por algoritmos de Árvore de Decisão (AD). Uma análise exploratória inicial mostrou que ocorrências de violência e relatos de insegurança estavam fortemente correlacionados nos trechos de via ao redor do campus. A análise temporal da distribuição da violência apresentou os incidentes concentrados à noite e durante os dias de semana. Além disso, a pesquisa mostrou que a percepção de segurança variou de acordo com o gênero e a escolha modal é menos sensível à percepção de segurança do que a ocorrência de violência, ou vinculação com a universidade. Por fim, os algoritmos de AD foram executados para explorar a relação das variáveis tratadas espacialmente (ou seja, o comprimento da rota até o campus, além da densidade de ocorrências e relatos de insegurança na rota) com a escolha modal. O último resultado obtido na análise foi que a distância até a universidade era relevante para a escolha modal apenas em rotas onde não há numerosos relatos de insegurança. A participação dos modos não motorizados foi mais expressiva nas rotas com maior percepção de insegurança, e em rotas com alta incidência de violência. Como não é razoável supor que mais viagens a pé são uma consequência dos roubos e sim o oposto, o estudo reforça a importância de aumentar a segurança nas regiões de alta incidência de viagens não motorizadas, de forma a não incentivar a migração destes usuários para modos motorizados.

Electrochemical modeling of lithium-ion cell behaviour for electric vehicles

Scipedia content — Tue, 26 Jan 2021 13:15:55 +0100

The future development of electric vehicles is mostly dependent of improvements in battery performances. In support of the actual research of new materials having higher performances in terms of energy, power, durability and cost, it is necessary to develop modeling tools. The models are helpful to simulate integration of the battery in the powertrain and crucial for the battery management system, to improve either direct (e.g. preventing overcharges and thermal runaway) and indirect (e.g. state of charge indicators) safety. However, the battery models could be used to understand its physical phenomena and chemical reactions to improve the battery design according with vehicles requirements and reduce the testing phases. One of the most common model describing the porous electrodes of lithium-ion batteries is revisited. Many variants available in the literature are inspired by the works of prof. J Newman and his research group from UC Berkeley. Yet, relatively few works, to the best of our knowledge, analyze in detail its predictive capability. In the present work, to investigate this model, all the physical quantities are set in a dimensionless form, as commonly used in fluid mechanics: the parameters that act in the same or the opposite ways are regrouped and the total number of simulation parameter is greatly reduced. In a second phase, the influence of the parameter is discussed, and interpreted with the support of the limit cases. The analysis of the discharge voltage and concentration gradients is based on galvanostatic and pulse/relaxation current profiles and compared with tested commercial LGC cells. The simulations are performed with the software Comsol® and the post-processing with Matlab®. Moreover, in this research, the parameters from the literatures are discussed to understand how accurate are the techniques used to parametrize and feed the inputs of the model. Then, our work shows that the electrode isotherms shapes have a significant influence on the accuracy of the evaluation of the states of charges in a complete cell. Finally, the protocols to characterizes the performance of commercial cells at different C-rates are improved to guarantee the reproducibility.; Le développement futur des véhicules électriques est lié à l’amélioration des performances des batteries qu’ils contiennent. Parallèlement aux recherches sur les nouveaux matériaux ayant des performances supérieures en termes d'énergie, de puissance, de durabilité et de coût, il est nécessaire développer des outils de modélisation pour : (i) simuler l'intégration de la batterie dans la chaine de traction et (ii) pour le système de gestion de la batterie, afin d'améliorer la sécurité et la durabilité. Soit de façon directe (par exemple, la prévention de surcharge ou de l’emballement thermique) soit de façon indirecte (par exemple, les indicateurs de l’état de charge). Les modèles de batterie pourraient aussi être utilisés pour comprendre les phénomènes physiques et les réactions chimiques afin d'améliorer la conception des batteries en fonction des besoins de l’utilisateur et de réduire la durée des phases de test. Dans ce manuscrit, un des modèles les plus communs décrivant les électrodes poreuses des batteries au lithium-ion est revisité. De nombreuses variantes dans la littérature s’inspirent directement du travail mené par le professeur J. Newman et son équipe de chercheurs à l’UC Berkeley. Pourtant relativement peu d’études analysent en détail les capacités prédictives de ce modèle. Dans ce travail, pour étudier ce modèle, toutes les grandeurs physiques sont définies sous une forme adimensionnelle, comme on l'utilise couramment dans la mécanique des fluides : les paramètres qui agissent de manière identique ou opposée sont regroupés et le nombre total de paramètres du modèle est considérablement réduit. Cette étude contient une description critique de la littérature incluant le référencement des paramètres du modèle développé par le groupe de Newman et les techniques utilisées pour les mesurer, ainsi que l’écriture du modèle dans un format adimensionnel pour réduire le nombre de paramètres. Une partie expérimentale décrit les modifications de protocoles mis en œuvre pour améliorer la reproductibilité des essais. Les études effectuées sur le modèle concernent d’une part l’identification des états de lithiation dans la cellule avec un attention particulière sur la précision obtenue, et enfin une prospection numérique pour examiner l’influence de chaque paramètre sur les réponses de la batterie en décharge galvanostatique puis en mode impulsion et relaxation.

Evaluation of Organic Protective Coatings as Corrosion Prevention for The Interior of Subsea Pipelines in Sour Gas Service

Scipedia content — Tue, 26 Jan 2021 13:13:54 +0100

A Deep Learning, Model-Predictive Approach to Neighborhood Congestion Prediction and Control

Scipedia content — Tue, 26 Jan 2021 13:10:35 +0100

Traffic congestion is a major concern, especially in large cities. To relieve a city of congestion impacts, transportation authorities typically base controls such as toll or congestion prices on expected congestion patterns. However, such strategies can be sub-optimal and may also lead to unintended negative consequences for two main reasons: (i) estimates of congestion state may be inaccurate if the proposed model inputs are too limiting or the assumptions are too restrictive and (ii) predictions may be too late to help. This creates the need for accurate predictions of traffic congestion well ahead of time to avoid delays and gridlocks. Traffic congestion is analyzed as a network-wide phenomenon. Large-scale spatial correlation and long-term temporal correlation govern traffic congestion propagation across the regional traffic network. Such correlations may be exploited to develop congestion prediction algorithms that are more effective than purely local predictions for the purpose of dynamic controls. Moreover, real-time information that is generated at locations across the network may signal the future congestion state, making it possible to take control measures in advance of worsening traffic situations. However, this approach also presents several new challenges, addressed in this research. Microscopic models of congestion do not produce realistic representations of network-wide congestion generation and its propagation. This motivates the analysis of congestion at neighborhood scale through macroscopic analysis. Recent literature has shown that Macroscopic Fundamental Diagrams (MFDs) are effective for developing neighborhood-wide congestion controls by controlling inflows from immediately surrounding areas or managing signal timings, in combination with flow conservation laws. To further enhance the use of MFDs for neighborhood-wide congestion management, traffic prediction over much larger geographic scales is incorporated. To that end, a numerically well-behaved score function, called Macroscopic Congestion Level (MCL), is proposed. The score is defined to be the ratio of the neighborhood’s vehicle accumulation, to its trip completion rate. Future values of this score are then predicted through a model using network state characteristics over the larger, region-wide network as input. These characteristics are represented as a vector of Origin-Destination (O-D) demands, link accumulations, link travel times and observed MCL values. The predicted score can be used to describe the likely congestion state in a neighborhood in the near future. It is challenging to develop congestion prediction algorithms that incorporate both spatial and temporal dependence at a network scale, adapt to sudden changes in demand patterns and forecast accurately over sufficiently long periods to implement controls. Deep learning is used to build sufficiently complex models for this task. Predictions are made using a deep learning model based on Long Short-Term Memory (LSTM) neural network architecture. The ideas are tested using simulation on a simple, hypothetical city-street network. A battery of simulation tests suggests that the model inputs are sensitive to different queue propagation scenarios, within and across days. MCL predictions made by the proposed deep learning model outperform a simple, yet competent, baseline model that assumes congestion on the next day mimics congestion today (referred to as the 1-Nearest Neighbor or 1-NN model). The prediction accuracy of the deep learning model is compared to that of the baseline 1-NN model in three situations that either aid the baseline model or adversely impact the deep learning model: (i) correlated O-D demands across multiple days, (ii) noisy observations, and (iii) partially observed network state. The limitations to the prediction accuracy in these situations are studied in simulated scenarios. Methods are suggested to improve accuracy in these situations either by modifying certain model hyper-parameters or by understanding the importance of various inputs. A Neural Attention Model-based framework is developed to extract the importance of various inputs and to better understand the inner workings of the deep learning model. Simulation experiments suggest that such a framework allows identification of major congestion-causing factors that may be targeted during control. Model predictions and the importance of various inputs are then used to test a dynamic control strategy, namely an app-based dynamic congestion toll at the beginning of a trip. Individuals are charged a toll at the beginning of each trip based on their predicted congestion impact. This dissuades them from traveling during the time and along the routes where they are likely to cause major harm to the performance of the network. An optimization problem is formulated to minimize cumulative MCL across a day in a target neighborhood while maintaining overall travel demand. The conditions for optimal tolls are obtained and approximations for these conditions are proposed through learned deep learning model parameters. Simulations indicate that a deep learning model-based dynamic toll reduces delays and charges lower toll than other tolling strategies that depend on predictions of demand. Possible improvements to the architecture of the deep learning model are discussed for congestion prediction in large networks. Signals in large networks are assumed to propagate through hypothetical graphs, such as graphs representing the road network or graphs representing the similarities in route-choices made by various individuals. The inputs are transformed to impose a graphical structure on them. A Graph Convolutional Neural Network (Graph-CNN) architecture is implemented for extracting relevant spatial features from this graphical input. An LSTM model makes real-time predictions based on these extracted features. Simulations of commuter trips on a pared-down freeway/highway network as well as full-scale network representing the San Francisco Bay Area suggest that the model accuracy is superior to that of the 1-NN model, the LSTM-only model, and a Graph-CNN + LSTM model without any road network or route-choice information.

Napovedovanje prometnega toka s pomočjo duffingovega oscilatorja in Wigner-Ville porazdelitve

Scipedia content — Mon, 25 Jan 2021 20:24:35 +0100

The main purpose of this study was to investigate the use of various chaotic pattern recognition methods for traffic flow prediction. Traffic flow is a variable, dynamic and complex system, which is non-linear and unpredictable. The emergence of traffic flow congestion in road traffic is estimated when the traffic load on a specific section of the road in a specific time period is close to exceeding the capacity of the road infrastructure. Under certain conditions, it can be seen in concentrating chaotic traffic flow patterns. The literature review of traffic flow theory and its connection with chaotic features implies that this kind of method has great theoretical and practical value. Researched methods of identifying chaos in traffic flow have shown certain restrictions in their techniques but have suggested guidelines for improving the identification of chaotic parameters in traffic flow. The proposed new method of forecasting congestion in traffic flow uses Wigner-Ville frequency distribution. This method enables the display of a chaotic attractor without the use of reconstruction phase space. Osnovni namen študije je raziskati uporabo metode razpoznavanja kaotičnih vzorcev za uporabo pri napovedovanju zgostitve prometnega toka v cestnem prometu. Prometni tok je spremenljiv, dinamičen in kompleksen sitem, ki je nelinearen nepredvidljiv. Nastanek zgostitve prometnega toka na cestnem odseku ocenjujemo v časovnem intervalu, ko le-ta prične presegati kapaciteto cestnega odseka. Pod določenimi pogojih je mogoče zaznati kaotični vzorec v prometnem toku. Pregled literature teorije prometnega toka in njegovo povezavo s teorijo kaosa je prikazal veliko teoretično in praktično vrednost tovrstne metode. Raziskane metode identifikacije kaotičnega vzorca v prometnem toku so pokazale omejitve, zato je v nadaljevanju opisana smernica za izboljšavo prepoznavanja kaotičnih vzorcev v prometnem toku. Predlagana nova metoda za napovedovanje zgostitev v prometnem toku predlaga uporabo Wigner-Ville frekvenčne porazdelitve. Postopek omogoča prikaz kaotičnega atraktorja brez uporabe rekonstrukcije faznega prostora.

R-WAKE - System release 2 document

Scipedia content — Mon, 25 Jan 2021 20:13:20 +0100

This report represents deliverable D4.2 “System Release 2” of the R-WAKE project, which describes the final system resulting from WP4 (System Development) intended to support the research objectives and scope to be addressed as central task of WP5 (Simulation and Analysis). WP5 stands as the user of the system, with the central objective of providing an evidence-based proposal for either maintaining current separation-standards, or adopting new potential separation improvements, that is, the R-WAKE Concept(s) to be further investigated. The report includes an update of the research objectives and scope, in terms of research questions and targeted study scenarios, which incorporates the recommendations discussed during the mid-term review of the project. The R-WAKE project addresses the SESAR 2020 Exploratory Research work-programme topic ER-07- 2015 - Separation Management and Separation Standards, within the area of Advanced Air Traffic Services (ATS). The R-WAKE project overall objective is to investigate the risks and hazards of potential wake vortex encounters in the en-route airspace, in current and futuristic operational scenarios, in order to assess potential enhancements for the Separation Standards and Separation Management methods in Europe.

Smart EV charging systems for Zero Emission Neighbourhoods

Scipedia content — Mon, 25 Jan 2021 20:11:31 +0100

The increased use of electric vehicles (EVs) calls for new and innovative solutions for charging infrastructure. At the same time, it is desirable to improve the energy flexibility of neighbourhoods. This paper presents state-of-the-art for smart EV charging systems, with focus on Norway. The aim of the study is to start investigating how smart EV charging systems can improve the energy flexibility in a Zero Emission Neighbourhood (ZEN). The intention is that the study will be useful when evaluating activities and technologies for the ZEN pilot areas. The paper presents energy demand for EV charging and typical charging profiles. Further, it describes how charging stations can interact also with the energy need in buildings and neighbourhoods, local energy production and local electric and thermal energy storage. Examples of commercial smart EV charging systems are described. The report lists some opportunities for testing smart EV charging in the ZEN pilot areas. Piloting of new technologies and solutions can provide more knowledge about smart EV charging systems, and how they can participate in matching energy loads in buildings and infrastructure with local electricity generation and energy storage. Acknowledgement This report has been written within the Research Centre on Zero Emission Neighbourhoods in Smart Cities (FME ZEN). The authors gratefully acknowledge the support from the Research Council of Norway, the municipalities of Oslo, Bergen, Trondheim, Bodø, Bærum, Elverum and Steinkjer, Sør-Trøndelag county, Norwegian Directorate for Public Construction and Property Management, Norwegian Water Resources and Energy Directorate, Norwegian Building Authority, ByBo, Elverum Tomteselskap, TOBB, Snøhetta, ÅF Engineering AS , Asplan Viak, Multiconsult, Sweco, Civitas, FutureBuilt, Hunton, Moelven, Norcem, Skanska, GK, Caverion, Nord-Trøndelag Elektrisitetsverk - Energi, Numascale, Smart Grid Services Cluster, Statkraft Varme, Energy Norway and Norsk Fjernvarme.

Vpliv novega Zakona o varnosti cestnega prometa na število prometnih nesreč v Sloveniji

Scipedia content — Mon, 25 Jan 2021 20:10:57 +0100

This paper studies the number of traffic accidents (TAs) in which people were killed or/and seriously injured over the period from January 1996 to October 2000 in Slovenia. The aim of this work is to ascertain if the reduction in the increase of the number of TAs after 1 May 1998, when the new road traffic safety law (RTSL) was adopted, is statistically significant. Assuming that the time series analysed contains also a seasonal component, we found out that the new RTSL had a very positive impact on the number of TAs, especially in the first year (approximately) after adoption. After this period the average increase of the number of TAs rose again, but not as high as before the adoption of the RTSL. V prispevku smo analizirali število prometnih nesreč s smrtnim izidom in hujšimi telesnimi poškodbami v času od januarja 1996 do oktobra 2000 v Sloveniji. Pri tem smo želeli ugotoviti, ali je mogoče govoriti o statistično značilnem zmanjšanju prirastka prometnih nesreč po sprejetju novega Zakona o varnosti cestnega prometa, ki je začel veljati 1. maja 1998. Ob upoštevanju periodičnega značaja opazovanega pojava smo ugotovili, da je novi zakon vplival na zmanjševanje števila prometnih nesreč predvsem v obdobju približno enega leta po sprejetju, nato pa je povprečni prirastek števila prometnih nesreč spet narasel, vendar je nižji kot pa v obdobju pred sprejetjem Zakona.

Transition to Shared Mobility

Scipedia content — Mon, 25 Jan 2021 20:06:04 +0100

This report examines how cities can manage the transition to shared mobility services. It expands on two earlier studies that looked at the citywide impact of replacing private cars with shared services, but did not address the question of implementation. Based again on mobility data for the city of Lisbon, Portugal, this report assesses issues around the scaling up of shared mobility services to the whole of the Metropolitan area and of their stepwise introduction. It also analyses the impacts of these services on the use of existing high-capacity public transport and on access to jobs, schools or health facilities across the whole study area, and explores how shared mobility can improve accessibility for users with impairments.The work for this report was carried out in the context of a project initiated and funded by the International Transport Forum's Corporate Partnership Board (CPB). CPB projects are designed to enrich policy discussion with a business perspective. Led by the ITF, work is carried out in a collaborative fashion in working groups consisting of CPB member companies, external experts and ITF staff.

Metodologija vrednotenja sistema odzivanja na letalsko nsrečo

Scipedia content — Mon, 25 Jan 2021 20:05:04 +0100

The paper investigates the ability to learn from an aircraft accident as the opportunities for learning diminish with the decline in the accident rate. A safety compromising case is studied as the processes of aircraft accident intervention and recovery can degrade the ability of an aircraft accident investigation process to enhance aviation safety by revealing accident causation. In the case study an assessment of the Slovenian aircraft accident response system was made. For the purpose of evaluating the successfulness of aircraft accident intervention and effectiveness of recovery, a model of aircraft accident response system requirements has been developed. Based on non-conformances identified by the model of requirements, remedial measures are proposed for the enhancement of the aircraft accident response system operation. Criteria for the definition of the transition from accident intervention to recovery are derived from the assessment findings in a manner not to impede the aircraft accident investigation effectiveness and efficiency. Proučevana je sposobnost učenja na napakah, ki so povzročile letalsko nesreče, saj se število priložnosti za učenje zmanjšuje z upadanjem števila letalskih nesreč. Predmet raziskave je primer z nevarnostnim potencialom, ki predvideva, da procesa intervencije in sanacije po letalski nesreči degradirata zmožnost procesa preiskovanja letalske nesreče, da z ugotovljenimi vzroki za nesrečo poveča raven varnosti v letalstvu. Evalviran je slovenski sistem odzivanja na letalsko nesrečo. Za namen evalvacije uspešnosti intervencije in učinkovitost sanacije po letalski nesreči je pred- stavljen razvit model zahtev za sistem odzivanja na letalsko nesrečo. Na podlagi neskladij, ugotovljenih z modelom zahtev, so predlagani korektivni ukrepi, ki bodo zagotavljali, da bo sistem odzivanja na letalsko nesrečo sposoben izboljševati varnost v letalstvu. Na podlagi ugotovitev presoje pa so izpeljana merila za definicijo trenutka oziroma pogojev prehoda iz intervencije v sanacijo po letalski nesreči na način, ki ne bo negativno vplival na uspešnost in učinkovitost procesa preiskovanja letalske nesreče.

Vpliv pripadnosti odnosu in zaupanja na kolaborativno vedenje v oskrbovalnih verigah

Scipedia content — Mon, 25 Jan 2021 20:01:42 +0100

The paper discusses theoretically and examines empirically the influence of the relationship commitment on collaborative behaviour in supply chains. In today's unstable business environment companies should collaborate to achieve mutual goals and competitive advantage. Defining relationship commitment and collaboration in supply chains (from social exchange theory point of view) is the basis of the research of this paper. Our aim is to examine the influence of relationship commitment on collaboration in supply chains in Slovenian economy. The qualitative research part discusses if the relationship commitment between partners in supply chain influences the collaborative behaviour between partners and which are the antecedents of relationship commitment. The research is based on a quantitative analysis of the online questionnaire survey made on the Slovenian economy. The research results show strong influence of trust and relationship commitment on collaboration between partners in supply chains. V članku teoretično osvetlimo in empirično dokazujemo vpliv pripadnosti odnosu na kolaborativno vedenje med partnerji v oskrbovalnih verigah. Sodelovanje je v sodobnem času hitrih sprememb nujno potrebno za doseganje zastavljenih ciljev in konkurenčne prednosti. Teoretično osnovo za naše raziskovanje predstavlja teorija družbene menjave. Naš cilj je preveriti vpliv pripadnosti odnosu na sodelovanje med partnerji v oskrbovalnih verigah v slovenskem gospodarstvu. S kvantitativno raziskavo smo ugotavljali, ali pripadnost odnosu in zaupanje vplivata na kolaborativno vedenje med partnerji v menjalnem odnosu v oskrbovalnih verigah, hkrati pa smo ugotavljali, kateri so dejavniki, ki vplivajo na pripadnost odnosu. Raziskavo smo izvedli s pomočjo anketnega vprašalnika, v katerega smo zajeli ustrezen delež organizacij v slovenskem gospodarstvu.

Pilot specifications - D10.1 INVADE H2020

Scipedia content — Mon, 25 Jan 2021 19:53:20 +0100

This document describes the general specifications for each of the pilots that will be part of the INVADE Project. The pilots are located in five countries: Norway, Netherlands, Bulgaria, Germany and Spain. It´s specified a list of sections for each one of the pilots. A general description, grid topology, flexibility services, technical details and a list of the general equipment that will be necessary in the execution of the project. For each of the pilots, the use cases will be related to the PUCs defined in D4.1 which has been a good input in order to identify the possible use cases for all the different pilots.

Effect of dents and gouges on the integrity of pipelines

Scipedia content — Mon, 25 Jan 2021 19:47:38 +0100

1993 hazardous liquid pipeline failure in Reston, Virginia and a 1994 gas pipeline failure in New Jersey are thought to have been caused by prior outside damage occurring several years before the failures. The type of damage visible on the pipes consisted of scrapes or gouges and may have been associated with dents caused by some machinery such as backhoe or bulldozer. This report examines the literature associated with dents and gouges in pipelines and similar shell structures. An analysis of rerounding of the damaged area is also carried out. It is concluded that dents in large pipelines are likely to reround under pressure and are, therefore, fairly innocuous. However, gouges and cracks associated with rerounded dents are not innocuous due to the superimposed residual stress field and should be removed if they are detected.

Strategies for mitigating air pollution in Mexico City

Scipedia content — Mon, 25 Jan 2021 19:44:25 +0100

This report examines air pollution mitigation strategies in Mexico City. It identifies a series of measures that can strengthen current approaches to air pollution mitigation adopted in Mexico's capital as well as nationally. Recommendation include actions in policy areas such as emissions standards and testing, incentives for cleaner vehicles, fuel quality, inspection and maintenance, restrictions on vehicle use, parking regulation and speed limits, air quality plans, enhancement and promotion of sustainable transport modes as well as improving enforcement and public communication. The publication assembles the findings of a workshop organised by the ITF and the Development Bank for Latin America (CAF) together with the Ministry of Environment of Mexico City (SEDEMA) in January 2017.This report is part of the International Transport Forum’s Case-Specific Policy Analysis series. These are topical studies on specific issues carried out by the ITF in agreement with local institutions.

Algorithms for compression and real-time internet services of intelligent road data

Scipedia content — Mon, 25 Jan 2021 19:42:36 +0100

Multipli konceptualni model zaznane kakovosti letalskih storitev med letom

Scipedia content — Mon, 25 Jan 2021 19:35:38 +0100

Despite growing literature on the different aspects of airline service quality in relation to behavioural intentions, less attention has been paid to some specific aspects of in-flight services. The focus of the present research is, therefore, on a multiple conceptual model of the quality of in-flight services in relation to passengers’ perception of value, followed by recommendations (word of mouth - WOM) of airlines, as well as the quality and comfort of airline seats. The study is performed using two databases of reviewers’/passengers’ opinions regarding the quality of in-flight airline services and airline seat comfort. Our research results reveal that the perceived comfort of the airplane seat is the most important factor of passengers’ perceived quality of in-flight airline services, which also considerably affects the passengers’ perception of value, and consequently moderates behavioural intentions (in our research, expressed through positive WOM). The analysis of the relative importance of the components of perceived airline seats’ comfort shows that seat width is the most significant factor that contributes to the overall perceived comfort of the airline seat. Kljub obsežni literaturi o različnih vidikih kakovosti letalskih storitev v povezavi z vedenjskimi namerami potnikov, so bili nekateri posebni vidiki kakovosti letalskih storitev med samim letom v preteklosti deležni manjše pozornosti. Tako je v ospredju pričujoče raziskave multipli konceptualni model zaznane kakovosti letalskih storitev med letom, v povezavi z zaznano vrednostjo s strani potnikov, kateri sledi priporočilo (“od ust do ust”) letalske družbe, kot tudi udobje ter zaznana kakovost letalskih sedežev. Raziskava temelji na dveh podatkovnih bazah, ki vsebujejo mnenja potnikov o zaznani kakovosti letalskih storitev med letom ter o udobnosti letalskih sedežev. Rezultati raziskave kažejo, da je zaznana kakovost letalskih sedežev s strani potnikov, najpomembnejši dejavnik zaznane kakovosti letalskih storitev med letom, ki hkrati znatno vpliva na zaznano vrednost storitve ter posledično oblikuje vedenjske namere (v naši raziskavi izražene s pozitivnim priporočilom “od ust do ust”). Analiza relativne pomembnosti posameznih komponent zaznane kakovosti letalskih sedežev pa kaže, da je širina sedeža najpomembnejši dejavnik, ki prispeva k celokupnemu zaznanemu udobju letalskega sedeža.