Scipedia: Documents published in 2009

Improving Dilemma Zone Protection Control Issues at Signalized Intersection Using a Web-Game

Scipedia content — Tue, 26 Jan 2021 16:23:51 +0100

Web games provide a platform for creative instructional activities that can capture the studentsâ attention towards the course. These games can be used to emulate the realistic situations which can be used as effective lab experiments that could give the students a hands-on experience using real world scenarios. This thesis presents an innovative web-based game developed for the demonstration of the driver-behavior at signalized intersections that can be used as a supplementary tool for the Transportation Engineering course. The game format is carefully designed to supplement the understanding of the class learning material through a fun environment. It was designed to be widely accessible through the internet and have an attractive user interface and was improved from the feedback obtained from the pilot study. The game is programmed on the .NET Framework using the Microsoft Visual C# as a core programming language, ASP to develop the web interface, and Microsoft Access as the databases for the program. The thesis also provides a methodological framework for collecting data about student engagement in a course and in particular presents the data collection procedure used in Transportation Engineering Course (CEE 4609). The collected data was analyzed to find the student engagement in the course after the introduction of the game. The thesis gives the conclusions drawn from the research with insights into possible drawbacks and scope for future improvements. Master of Science

Developing Infrastructure to Promote Electric Mobility

Scipedia content — Tue, 26 Jan 2021 16:19:42 +0100

Electric mobility, E-mobility, will play a central role in a sustainable future transport system. The potential of curbing climate change in both short and long term are significant. Emobility will also offer the possibility to leapfrog the Internal Combustion car, IC-car, economy for developing countries. The low dependence of oil will be a benefit but E-mobility will demand a well functional electricity grid. Development of this grid will be beneficial for the developing world. For the European society E-mobility will in long term offer lower operating costs, decreased dependence of oil and lower emission of pollutants and Green House Gases, GHGs. All these factors are beneficial for the European society. The transition to E-mobility will depend upon a set of different factors and will call for different actions in order to overcome the barriers of E-mobility. A well developed charging infrastructure will be important in order to offer the full potential of E-mobility. The infrastructure will develop along with the market introduction of Electrical Vehicles, EVs. It is important that there are existing charging alternatives in the early introduction phase of EV in order to avoid the stagnation in the transition toward E-mobility. In order to provide the proper conditions for E-mobility, the determining factors must be investigated and evaluated. The four main factors are economical, social, R&D and infrastructure. The European driving patterns meet the offered operating range of an EV with ease. This means that EV has the potential to become an inner city vehicle under existing conditions. The investigation of the four determining factors leads to a base from which an implementation plan is suggested. The implementation plan is directed toward governments, energy utilities and other active participants in the development. The key factors of the implementation plan are to actively engage in the market, see E-mobility as a disruptive technology, use spin-off companies and social transparency. In order to gain the most from the implementation plan it is important that the correct actions are taken at the correct time. Therefore the transition period is divided into three phases; the introduction phase, the commercial phase and the re-development phase. The introduction phase will create the basic conditions for E-mobility. Government’s main action will be to invest in EVs and offer subsidies and other incentives to major companies that will equip their vehicle fleets with EVs. These actions will send signals toward vehicle Original Equipment Manufactures, OEMs, and other actors that the market of EVs is worth investing in. During the introduction phase try-out sessions, demonstrations and hearings will be important in order to communicate the advantages of E-mobility to society. Energy utilities will work to create roaming deals and standardization of important components and characteristics. The commercial phase is the most important phase for social adoption of E-mobility. During this phase commercial businesses will use EV charging a competitive advantage. New business models will be one of the keys to fully adoption of E-mobility. Cross industry alliances will reduce the initial cost, offer the service of a vehicle without owning it and leasing deals. The perception of travelling will shift and reduction of operating cost will be evaluated against travel time and planning. The re-development phase is based on a society that has adopted E-mobility. The development will proceed in order to offer more advantages to drivers but also to increase efficiency and to use the full potential of E-mobility.

Traffic engineering and quality of service in the internet

Scipedia content — Tue, 26 Jan 2021 16:05:20 +0100

Política de transporte público en la ciudad de los ’90. Reglamentación y concentración empresaria en el autotransporte metropolitano de Buenos Aires

Scipedia content — Tue, 26 Jan 2021 16:04:24 +0100

El objetivo del trabajo es mostrar la construcción de una tesis doctoral realizada en la Universidad de Buenos Aires. La organización de la presentación intenta reflejar el desarrollo del proceso de investigación. En función de este hilo conductor, se seleccionan comentarios sobre la estrategia de investigación (tanto teórica como empírica), y sobre algunos de sus resultados, conclusiones y aportes. Se ofrece, pues, una versión resumida y parcial de los contenidos de la tesis. El tema de la investigación examina la política de transporte público urbano de los años ’90, enfocándose en la relación entre la reconversión empresaria y la revisión reglamentaria del auto transporte metropolitano de Buenos Aires. Se busca comprender si entre ambos existe una relación y de qué tipo, y asimismo interpretar sus causas y consecuencias.

Agent-based simulations in urban economics: Applications to traffic congestion and housing markets

Scipedia content — Tue, 26 Jan 2021 15:46:46 +0100

Simulations have considerable potential for the analysis of the evolution of economics systems, a subject often neglected by mainstream economics where the focus is on static equilibria. This thesis investigates the potential of this approach in urban economics. The purpose is to examine how global phenomena emerge from the interactions of economic agents. This is a promising method as a classical economics, lacking the appropriate analytic tools, concentrates on the existence of equilibria and refrains from investigating their stability. This study demonstrates the potential of simulations in three models. Firstly, in a standard model of traffic congestion it is shown that the Nash equilibrium is unstable and cannot be reached dynamically. Secondly, it is shown that simulations of the formation of urban land rents, reproduce elements of the theoretical equilibrium, and also endogenous vacancies, which are an important real-world phenomenon. Thirdly, an agent-based model of the housing market, which reproduces important empirical phenomena such as price dispersion, non-zero search times and vacancies, has been developed. The model provides a basis for the exploration of the complex dynamics of this market.; Les simulations représentent une méthode de choix pour analyser la dynamique d'évolution des systèmes, que l'économie classique laisse de côté car elle s'intéresse essentiellement à l'équilibre. Dans ce travail, nous avons étudié l'intérêt d'une telle approche dans le cas des systèmes d'économie urbaine. Il s'agit de comprendre comment des interactions entre des agents économiques émergent dans l'état global du système, en s'intéressant notamment à la dynamique de convergence vers un éventuel équilibre. Cette méthode est prometteuse, car faute de méthodes analytiques performantes, l'économie classique ne s'intéresse en général qu'aux équilibres, sans se soucier des possibilités concrètes pour l'atteindre. Notre étude a montré l'intérêt des simulations dans trois cas précis. D'abord, dans un modèle classique de la congestion routière il est démontré que l'équilibre prédit par la théorie économique était instable, et qu'il ne pouvait pas être atteint en pratique. Ensuite, il est démontré que des simulations de la formation de la rente foncière urbaine dans un modèle simple, permettaient de retrouver certains aspects de l'équilibre classique, mais rajoutaient de manière endogène un élément important : le taux de vacances observé dans la réalité. Enfin, nous avons développé un modèle multi-agents du marché immobilier, qui permet de retrouver des phénomènes empiriques importants telle que la dispersion des prix, des temps de recherche non nuls et des logements vacants. Le modèle autorise aussi une exploration de la dynamique complexe de ce marché.

Hava Trafik Kontrolünde Çarpışmaların Önlenmesi

Scipedia content — Tue, 26 Jan 2021 15:45:11 +0100

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010

Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2010

Günümüzde ki Hava Trafik Kontrol sistemi, hava trafiğini kontrol etmek ve yönlendirmek için fazlasıyla merkezileşmiş durumdadır. Bu karmaşık durumun üstesinden gelebilmek için mevcut sistemin daha dağıtılmış bir kontrol sistemine doğru evrilmesi gerekmektedir. Bu evrimin “serbest uçuş” kavramıyla yapılması düşünülmektedir. Hava Trafik Kontrolü’nde “serbest uçuş” kavramının uygulanmasında ki en büyük problem ise çarpışmaların çözümlenmesi problemidir. Bu çalışmada yeni bir çarpışma çözümlenmesi yöntemi, potansiyel alan yöntemi, geliştirilmiş ve benzetimleri gerçekleştirilmiştir. Potansiyel alan yöntemi robotlar için rota planlamasında yeni bir yöntem olmamakla birlikte, uçakların çarpışma problemlerine uygulanması yenidir. Bu yöntemin uyarlanmış bir uygulaması uçakların çarpışma problemini çözmek için kullanılmıştır. Üç ayrı çarpışma senaryosu çalışılmış ve benzetimleri MATLAB üzerinde koşturulmuştur. Ancak, bu yöntem robotlar için geliştirildiği için, örneklerde uçakların gerçekleştiremeyecekleri hareketler ortaya çıkmaktadır. Bunu önlemek amacı ile iki yeni uygulama geliştirilmiştir. Bunlar; açı sınırlama yöntemi ve gelecek tahmini yöntemidir. Her iki yöntem içinde senaryolar üzerinde çalışılmış ve görülmüştür ki yeni yöntemler daha uygulanabilir ve uçuş rotası ve zaman açışından daha iyi sonuçlar vermektedir. Bu çalışmanın ana amacı “serbest uçuş” kavramını vurgulamak ve bu kavramın uygulanabilmesi için çalışmalar yapmaktır. Serbest uçuş tabanlı Hava Trafik Kontrol sistemi daha gelecekte uygulanması düşünülen bir seviyededir. Onun için bir uçuş sisteminin uçuş ve çarpışma çözümlemeleri hakkında özellikleri henüz net tanımlanmamıştır. Bu çalışma gelecekte oluşturulacak gerçek bir çarpışma çözümleme tekniğine fikir oluşturma amaçlı bir çalışma olarak da değerlendirilebilir.

Current ATC system is more centralized to control and direct the air traffic, however to overcome this complex situation the system should be evolved towards more decentralized control systems. This evolution thought out to be made by “free flight” (FF) concept. The most important problem that should be resolved to implement FF concept in ATC is conflict resolution problem. In this study a new conflict resolution algorithm, potential field method, is developed and simulations are performed. Potential field method is not newly method for the robot path planning, however implementation of this method to aircraft conflict problems is quitely new. A modified application of this method is carried out to resolve conflicts in ATC. Three conflict scenarios are studied and their simulations are runned with MATLAB. However, because of this method developed for robot path planning, there are some unexpected movements, that aircraft can not perform, in examples. To avoid this two improved applications are developed which are angle restriction method and future estimation method. For both improved methods, scenarios are studied and it is depiceted that new methods are more applicable and have better solutions in flight trajectory and time perspective. The main aim of this study is to emphasize the “free fligt” concept and try to enable the implementation of FF. FF based ATM is yet in the level of a thought to be applied in the future. Therefore the flight and conflict resolution specifications of this kind of a flight system are not yet well defined. This research should be considered as a study of a conflict resolution technique that may give ideas for constructing the actual ones in the future.

Yüksek Lisans

M.Sc.

Otobüs Duraklarının Etki Alanının Belirlenmesi

Scipedia content — Tue, 26 Jan 2021 15:41:36 +0100

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010

Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2010

Çalışmanın ilk bölümünde erişim ve toplu taşımaya erişim açıklanmıştır. Toplu taşıma duraklarına yürüme ile erişim çalışmaları incelenmiştir. İkinci bölümde, otobüs duraklarına erişim uzaklığının belirlenmesi amacıyla bir anket çalışması yapılması ve sonrasında ankete katılan her bir kişinin ne kadar uzaktan geldiğinin ölçülmesi yöntemi izlenmiştir. İstanbul’un Şişli semtindeki Elmadağ, Harbiye, Pangaltı, Osmanbey, Şişli Camii ve Şişli Etfal duraklarında yapılan anket çalışması ile duraklara erişme uzaklığı ölçülmeye çalışılmıştır. Yolcuların yaşlarına, cinsiyetlerine, otomobil sahipliğine, ev sahibi olma durumuna, aylık gelir düzeyine ve yolculuk amaçlarına göre otobüs duraklarına erişim uzaklığı bulunmuştur. Sonuç bölümünde, anket sonucunda çıkan Elmadağ, Şişli Etfal ve Şişli Camii duraklarında yaklaşık 400 m, Harbiye, Pangaltı ve Osmanbey duraklarında ise yaklaşık 600-670 m ile durağa yürüme uzaklıkları , daha önce toplu taşımaya erişim ile ilgili yapılan çalışmalarda çıkan sonuçlarla karşılaştırılmıştır.

At the first stage of this study, accessibility and access to public transportation are explained. Access to public transport stations by walk is searched. At the second stage of the study, a method is used that first making a survey for the purpose of determining the distance of access to public transport and afterwards calculating how far the people coming from.The subject of this study is measure the access distances to the 6 certain stations which are located in Şişli by conducting surveys. The access distance was measured according to age, gender, monthly salaries and transportation purposes of the passengers. In conclusion, these results of surveys are compared ; there is 400 m.distance to Elmadağ, Şişli Etfal and Şişli Camii stations and 600-670 m. distance at Harbiye, Pangaltı and Osmanbey stations both by walk. Also the results from the former research about access to public transport are compared.

Yüksek Lisans

M.Sc.

Multi-layer traffic engineering in optical networks under physical layer impairments

Scipedia content — Tue, 26 Jan 2021 15:40:09 +0100

nkara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent University, 2010. Thesis (Ph. D.) -- Bilkent University, 2010. Includes bibliographical references leaves 153-165. We study Traffic Engineering (TE) in Multiprotocol Label Switching (MPLS)/Wavelength Division Multiplexing (WDM) networks and propose a multi-layer TE method. MPLS provides powerful TE features for IP networks and is widely deployed in backbone networks. WDM can increase the transmission capacity of optical fibers to tremendous amounts, therefore it has been the dominant multiplexing technology used in the optical layer. The proposed multi-layer TE solution facilitates efficient use of network resources where the TE mechanisms in the MPLS and WDM layers coordinate. We consider a static WDM layer and available traffic expectation information. The TE problem arising in the considered scenario is the Virtual Topology Design (VTD) problem, which involves the decision of WDM lightpaths to be established, calculation of MPLS Label Switched Paths (LSPs) on the resulting virtual topology, and calculation of the routes and wavelengths in the physical topology that correspond to the lightpaths in the virtual topology. We assume a daily traffic pattern changing with the time of day and aim to design a static virtual topology that satisfies as much of the offered traffic as possible, over the whole day. In our proposed solution, the multi-layer VTD problem is solved by decomposing it into two sub-problems, each involving in a single layer. The decomposition approach is used in the thesis due to the huge computational burden of the combined solution for real-life networks. The sub-problem in the MPLS layer is the design of the lightpath topology and calculation of the LSP routes on this virtual topology. This problem is known to be NP-complete and finding its optimum solution is possible only for small networks. We propose a Tabu Search based heuristic method to solve two versions of this problem, resource oriented and performance oriented. Integer Linear Programming (ILP) relaxations are also developed for obtaining upper and lower bounds. We show that the gap between the produced solutions and the lower and upper bounds are around 10% and 7% for the resource and performance oriented problems, respectively. Since the actual traffic can show deviations from the expected values, we also developed an MPLS layer online TE method to compensate the instantaneous fluctuations of the traffic flows. In the proposed method, the LSPs are rerouted dynamically using a specially designed cost function. Our numerical studies show that using the designed cost function results in much lower blockings than using commonly used Widest Shortest Path First and Available Shortest Path First approaches in the literature. The corresponding sub-problem of the multi-layer VTD problem in the WDM layer is the Static Lightpath Establishment (SLE) problem. Along with the capacity and wavelength continuity constraints, we also consider the Bit Error Rate (BER) constraints due to physical layer impairments such as attenuation, polarization mode dispersion and switch crosstalk. This problem is NP-complete even without the BER constraints. We propose a heuristic solution method and develop an exact ILP formulation to evaluate the performance of the proposed method for small problem sizes. Our proposed method produces solutions close to the optimum solutions for the cases in which the ILP formulation could be solved to optimality. Then, these solution methods for the single layer sub-problems are combined in a multi-layer TE scheme to solve the VTD problem in both layers jointly. The proposed TE scheme considers the physical layer limitations and optical impairments. This TE scheme can be applied by keeping each layer’s information hidden from the other layer, but our simulations show that it can produce more effective and efficient solutions when the physical layer topology information is shared with the MPLS layer. We also investigate the effect of non-uniform optical components in terms of impairment characteristics. The numerical results show that more traffic can be routed when all the components in the network have moderate impairment characteristics, compared to the case in which some components have better and some have worse impairment characteristics. Şengezer, Namık Ph.D.

Heavy vehicles and safety in horizontal curves highway design.

Scipedia content — Tue, 26 Jan 2021 15:36:09 +0100

curvas horizontais das rodovias notoriamente colecionam acidentes de trânsito, nos quais geralmente os automóveis derrapam e escapam pela tangente, enquanto que os veículos pesados costumam tombar lateralmente. Os critérios consagrados de projeto geométrico das curvas, consideradas planas, ignoram a propensão dos veículos pesados ao tombamento lateral, confiando apenas nas forças de atrito lateral e na superelevação transversal da via para a manutenção do veículo em trajetória segura. O presente trabalho pretende desenvolver modelo de projeto que forneça margens de segurança tanto contra o escorregamento e o tombamento lateral de veículos pesados (semi-reboques) em curvas horizontais com greide descendente. O modelo proposto no presente estudo é sensível a fatores de segurança intrínsecos e extrínsecos aos veículos, incluindo características geométricas longitudinais e transversais da pista, e a variação da trajetória do veículo dentro da curva. Os resultados obtidos demonstram que os critérios de projeto atuais não garantem a segurança de semi-reboques em curvas descendentes de raio mínimo, principalmente nas curvas de menor velocidade. O critério desenvolvido permite o estabelecimento de margens de segurança para a regulamentação de velocidade em curvas horizontais descendentes já existentes, bem como possibilita a determinação da velocidade de projeto segura para curvas descendentes em novas vias. The grade effect on highway horizontal curves is notorious for traffic accidents because automobiles tend to skid and leave the road whereas commercial loaded vehicles tend to roll over. The standard criteria for the geometric design of these curves, which are considered flat, ignore the heavy vehicles propensity for rollover by relying solely on the forces of lateral friction and on the road superelevation in order to keep the vehicle in a safe trajectory. The current study has been set out in order to develop a model that will yield margins of safety to prevent skidding and rollover of heavy vehicles (semi-trailers) on horizontal descending highway curves. The model proposed in the present study is sensitive to safety variables both intrinsic and extrinsic to the vehicles, including longitudinal and transversal characteristics of the road, and vehicles trajectory variations at horizontal curves. The results of the study show that the currently adopted safety guidelines do not guarantee the safety of such articulated vehicles on grade curves with minimum radii, mostly at lower speeds curves. As a result, the proposed criteria allows the establishment of margins of safety that can be applied to regulatory speed signs on existing horizontal descending curves, and for the setting of safe design speeds for descending curves on new highways.

Strategic variables for National Air Transport

Scipedia content — Tue, 26 Jan 2021 14:34:13 +0100

M20, Z19 Air Transport allowed over time, to reduce distances, eliminate borders, increase mobility and contribute to a new model of society as we know today.These are some of the reasons why in recent years, there were times of growth, development and higher demand, strengthening its role in a society increasingly globalized. While environmental costs caused by air transport are often highlighted, very little is said about its benefits. Broadly speaking it can be said that aviation contributes to worldwide trade by opening access to several markets, for investment through internationalization and access to new resources and skills in order to stimulate productivity and encourage competition as well as tourism. Its importance should not therefore be questioned or neglected. On the contrary, the preparation of its future should be a constant concern by analyzing the main challenges for the sector and for all others involved. There are many paths to choose and several variables that must be taken into account. This study aims to analyze the main variables, to present perspectives, alert to emerging opportunities and external adverse factors, and to identify some options that can better serve Air Transport in Portugal. The purpose of this dissertation is also to highlight the weaknesses of this sector in Portugal and the need to consider a medium/long-term vision and a strategy for such an important sector for the Portuguese economy and society. O Transporte Aéreo permitiu ao longo dos tempos, reduzir distâncias, eliminar fronteiras e contribuir para o modelo de sociedade em que hoje vivemos, sendo estas algumas das causas pelas quais tem vivido nos últimos anos, tempos de grande expansão e procura, não só a nível de turismo como também em termos de viagens em negócios, reforçando ainda mais o seu papel numa sociedade cada vez mais globalizada. A sua importância não deve por isso ser posta em causa ou negligenciada, devendo ser uma preocupação constante a preparação do seu futuro analisando quais os desafios que se colocam ao sector e a todos os que o constroem. Existem diversos caminhos que podem ser escolhidos e várias variáveis a ter em conta. Este estudo tem como objectivo analisar essas variáveis e identificar caminhos que possam melhor servir o transporte aéreo Português. Enquanto os custos em termos ambientais provocados pelo transporte aéreo estão bem documentados, muito pouco é dito acerca dos seus benefícios. Em traços gerais pode dizer-se que a aviação contribui para as trocas comerciais abrindo acesso a diversos mercados, para o investimento através da internacionalização e do acesso a novos recursos e competências, para a produtividade estimulando a competição e para o turismo através da facilidade de unir viajantes e regiões. Este projecto ambiciona também alertar as fragilidades do sector em Portugal e a necessidade de pensar a médio longo prazo uma visão e uma estratégia para uma área de negócio tão importante para a economia e para a sociedade Portuguesa.

Fleet design for maritime distribution of stone products in NorStone

Scipedia content — Tue, 26 Jan 2021 14:30:38 +0100

The effectiveness of servqual in measuring service quality and the impact of technology on customer satisfaction

Scipedia content — Tue, 26 Jan 2021 14:03:07 +0100

Service quality and customer satisfaction are becoming increasingly important in today‟s business environment which is characterised by fierce competition between the service providers. In this regard it is very imperative that companies assess themselves by measuring service quality. Consequently, areas of the service with low service quality would be identified and improved. Therefore, this thesis focuses on the effectiveness of SERVQUAL in measuring service quality and reveals the positive impact technology has on customer satisfaction in public transportation. To do this, we developed a questionnaire within the framework of the SERVQUAL dimensions of reliability, responsiveness, assurance, empathy and tangible. With a scale of 1 to 7, respondents of our questionnaire who are users and customers of the public bus companies; Karlstad city bus which we labelled business level 1(B1) and intercity buses like Swebus and Värmland Trafik which we labelled business level 2 (B2) were able to evaluate the service quality of these companies by grading them. Based on the results of our research in which we asked respondents to mention some of the areas of the service process in which they had encountered unfavourable service experiences, we were able to determine the areas of the service process from which the customer complaints came from. We compared these results with the customer complaints received by the management of the public Bus Company and noticed that they were similar. Majority emerged from areas of the service process whereby the customer came in contact with the employees or the service failure could be directly associated with the employee. After comparing these complaints with the results of questions in our questionnaire developed within the framework of the SERVQUAL dimensions, we noticed that those questions with larger GAP 5 implying lower service quality were actually a reflection of the areas of the service process from which customer complaints came from. In this regard, we were able to conclude that SERVQUAL was effective in measuring the service quality in public transportation. In addition, we ranked the questions in the questionnaire and noticed that those areas of the service process whereby the employees and the customers interact (come in contact) or whose service failure can be directly associated with an employee had low grades and ranked below the mean and median of all the questions in the various dimensions, whereas those areas of the service process where technology is used or customers had the opportunity to make use of Self Service Technology ranked above the mean and median. This was a clear indication that technology is a service quality driver and positively impacted customer satisfaction in public transportation.

Graphical visualization and analysis tool of data entities in embedded systems engineering

Scipedia content — Tue, 26 Jan 2021 14:01:07 +0100

Several decades ago, computer control systems known as Electric Control Units (ECUs) were introduced to the automotive industry. Mechanical hardware units have since then increasingly been replaced by computer controlled systems to manage complex tasks such as airbag, ABS, cruise control and so forth. This has lead to a massive increase of software functions and data which all needs to be managed. There are several tools and techniques for this, however, current tools and techniques for developing real-time embedded system are mostly focusing on software functions, not data. Those tools do not fully support developers to manage run-time data at design time. Furthermore, current tools do not focus on visualization of relationship among data items in the system. This thesis is a part of previous work named the Data Entity approach which prioritizes data management at the top level of development life cycle. Our main contribution is a tool that introduces a new way to intuitively explore run-time data items, which are produced and consumed by software components, utilized in the entire system. As a consequence, developers will achieve a better understanding of utilization of data items in the software system. This approach enables developers and system architects to avoid redundant data as well as finding and removing stale data from the system. The tool also allows us to analyze conflicts regarding run-time data items that might occur between software components at design time. A Data-Entity Approach for Component-Based Real-Time Embedded Systems Developmen

A public transportation route planning tool: ToTRoP

Scipedia content — Tue, 26 Jan 2021 13:57:54 +0100

TEZ8153 Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2010. Kaynakça (s. 55-57) var. xi, 59 s. : res., hrt., tablo ; 29 cm. In this thesis, a web based public transportation route planning tool (ToTRoP) is developed. The routes are generated to transport people to a specific location (a hospital, a stadium, a university campus etc.) while keeping minimum cost and maximum passenger number. ToTRoP uses Google APIs to convert text based address data into geographical location data and then generates the most beneficial routes to a target point. ToTRoP is used to derive possible transportation routes from the city of Adana to Çukurova University's campus based on the anonymous address data of the freshmen students. According to the test results, transportation of approximately 76 % of the students is enabled through seven routes. The tool can work integratedly with other GIS software thanks to WFS support. This feature enables it to be a SOA based GIS application. Bu tezde, halk otobüsü taşımacılığı için coğrafi bilgi sistemi tabanlı rotalar üreten bir web aracı geliştirilmiştir. Farklı adreslerde yaşayan kişileri hedef bir noktaya (hastane, stadyum, üniversite kampüsü v.b.) taşımak amacıyla üretilen rotaların hedefe minimum maliyetle en fazla yolcunun erişmeleri amaçlanmıştır. Sunulan araç verileri coğrafik verilere dönüştürmek için Google Map API'leri kullanır ve hedef noktaya ulaşmak için en faydalı rotaları üretir. Bu araç Çukurova Üniversitesi kampüsüne ulaşım için yeni öğrencilerin adres bilgilerini baz alarak uygulanabilir taşıma rotaları üretti. Bu test verilerine göre yedi tane rota ile öğrencilerin yaklaşık %76 sının taşınması sağlandı. Ek olarak OGC tarafından tanımlanan WFS servisi ile diğer CBS uygulamaları ile entegre olabilir. Bu saye de yapılan uygulama SOA tabanlı olmuştur.

An Approach to Reducing Bus Bunching

Scipedia content — Tue, 26 Jan 2021 13:57:31 +0100

The tendency of buses to bunch is a problem that was defined almost 50 years ago. Since then, there has been a significant amount of work done on the problem; however, the tendency of the current literature is either to only focus on the surface causes or to rely on simulation to create results instead of model formulation. With GPS installed on many buses throughout the world, the data is only being used for monitoring and informing the user. This research proposes a new approach to solving the problem that uses the GPS data to directly counteract the cause of the bunching by allowing the buses to cooperate with each other and determine their speed based on relative position. A continuum approximation model is presented as a tool to systematically analyze the behavior of the system and test the proposed control. In order to validate the model and the control, a simulation tool is used to model the system in a more realistic, discrete way. The control is shown to produce bounded deviations in spacing consistent with those predicted by the model. The resulting bus system will not bunch with only a small reduction in commercial speed.

Hızlı Otobüs Taşımacılığı Ve İstanbul Örneği

Scipedia content — Tue, 26 Jan 2021 13:56:08 +0100

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010

The Road Traffic Management Corporation: a case study

Scipedia content — Tue, 26 Jan 2021 13:43:28 +0100

M.Ing. The focus of this dissertation is on the evaluation of management in traffic safety, and how it is applied, using the Road Traffic Management Corporation (RTMC) as a case study. Road Traffic Management in South Africa is in a state of crisis. The constitution provides for concurrency with respect to road traffic management, however, no mechanism has been implemented for co-operation and coordination. It has been found that the current institutional arrangements are not conducive to co-ordination and rapid interventions. Due to the scarcity of resources and the desire to streamline the institutional arrangements, an innovative model has been developed which will perform road traffic management collectively, the Road Traffic Management Corporation, RTMC. The implementation of the RTMC will require full co-operation and acceptance by all the various departments concerned, from National Government level, through to Provincial levels, and the Local Authorities. Before the Corporation can be implemented, the funding needs to be secured, and the source of the funding must be stable and committed. The implementing of such a corporation will be delicate, and organizational structure needs to be clear to all parties. At this early stage of the RTMC, the methods of management already used by the RTMC need to be compared to proper management principles, to ensure that the RTMC will have the best structure to ensure its success. Any uncertainties or concerns that may exist among those involved at lower levels can be communicated to top-level management implementing the corporation. By conducting an independent, external investigation, any short falls can be identified which may have been over looked previously. This dissertation aims to ensure that the RTMC adheres to the relevant management principles, focussing on the objective of improving road safety. A questionnaire is devised for the National Department of Transport, so that an independent view of the vision of the RTMC can be acquired. The organizational structure proposed by the RTMC is examined and evaluated to determine the relationship, communication channels, functions and responsibilities, which are intended between the various levels of management and stakeholders. The funding of a corporation such as the RTMC is considered, as the source of such funds needs to be secured before the RTMC can be implemented. A preliminary budget prepared for the RTMC is compared to what funding has been made available. The main objective of the RTMC is to improve road safety. Therefore, the process it intends to use is evaluated to determine whether the goals it intends to achieve through this process are realistic. The engineering function required to improve road safety will also be evaluated in terms of what can be done by engineers to improve the safety on South African roads.

Observations of lane changing patterns on an uphill expressway

Scipedia content — Tue, 26 Jan 2021 13:32:27 +0100

mechanism is unveiled by which traffic congestion forms on a 3-lane, uphill expressway segment, and causes reductions in output flow. Vehicular lane-changing (LC) is key to the mechanism, particularly LC induced by speed disturbances (SDs) that periodically arise in the expressway's median and center lanes. Early in the rush, when flow was relatively low in the shoulder lane, drivers readily migrated toward that lane to escape the oncoming SDs. The shoulder lane thus acted as a ``release valve'' for the high vehicular accumulations created by the SDs, such that forced vehicular decelerations were short-lived. The release valve failed only later in the rush, when flow increased in the shoulder lane in response to rising demand. LC induced by the SDs thereafter became disruptive: the decelerations they imposed spread laterally, and a persistent queue formed in all lanes. Long-run output flow dropped each day by 4% to 11% once the queue engulfed the base of the incline, and impeded vehicle ascent.The more conspicuous details of this mechanism were observed in loop detector data measured over many days at the site, and are consistent with observations previously made at other sites. More subtle details became visible by examining thousands of vehicle trajectories extracted on a single day from a series of eleven roadside video cameras. (Video processing tools were developed and used for this purpose.) Many of the subtleties are compatible with an existing theory of multi-lane traffic. All of this suggests that the present findings can be generalized to other uphill expressway segments. Practical implications are discussed.

Cargo spaces in São Paulo metropolitan region

Scipedia content — Tue, 26 Jan 2021 13:31:26 +0100

caracterização do sistema de transporte de carga na Região Metropolitana de São Paulo, apresentada neste trabalho, apoia-se nas diversas formas de organização das atividades e serviços de transporte de carga, pondo em evidência os novos espaços e fluxos que foram gerados nas últimas duas décadas. A questão da circulação e transporte de carga na Região Metropolitana de São Paulo e suas relações com as transformações na organização produtiva são abordadas, entendidas como aspectos importantes da dinâmica sócioespacial da metrópole paulistana. Admite-se que as transformações na organização produtiva da metrópole implicaram o crescimento dos fluxos de bens e mercadorias que, ao afetar a organização da circulação geral e dos serviços de transporte de carga, podem ter repercutido na organização espacial urbana. Tais transformações, também decorrentes de inovações na organização dos próprios serviços de transporte de carga, vêm sendo caracterizadas como atividade logística e visam ganhos globais no processo de produção. Assim sendo, alguns dos novos elementos do sistema de transportes de carga podem estar relacionados a processos sócio-espaciais característicos da formação metropolitana contemporânea, que se expressam em diferentes formas de distribuição espacial das atividades econômicas. Partindo-se desse pressuposto são descritos alguns aspectos da organização da produção e das atividades de comércio e serviços que têm resultado em mudanças no sistema urbano de cargas, argumentando-se que tais mudanças fazem parte das dinâmicas de transformação do espaço metropolitano e confirmam a força de polarização e articulação concentrada na RMSP. The characterization of load transport system in Metropolitan Region of São Paulo, exposed in this work, holds on several ways of activities and duties organization for cargo transport, calling the attention to the new spaces and flows that were engendered on the last decades. The issue of cargo traffic and transport in São Paulo Metropolitan region and its relation with the transformation of the productive organization are broached, understood as important aspects of social spatial dynamic of São Paulo Metropolis. It is admitted that the transformation of productive organization of the metropolis implied in the increase of the goods and merchandises flows, that when affecting the organization of the general circulation and cargo transport duties, may have rebounded in urban spatial organization. Such transformations, also decurrent from innovations in load transport duties own organization, are becoming characterized as logistics activities and aim global profits in the production process. Thus, some of the new elements of the load transport system may be related to social spatial processes characteristic of the contemporary metropolitan formation, which express itself in different ways of spatial distribution of the economical activities. Starting from this presupposition some aspects of the production organization and of the trading and duties activities are described, which have turned out to changes in the urban load system, arguing that such changes constitute the dynamics transformations of the metropolitan spaces and confirm the polarization strength and the concentrated articulation in RMSP (São Paulo Metropolitan Region).

Mécanismes de routage inter-domaine multi-critère. Vers des services inter-opérateurs à performances garanties.

Scipedia content — Tue, 26 Jan 2021 13:30:28 +0100

The issue of providing Quality of Service (QoS) in the Internet is becoming more and more important because of two phenomena: (1) the growth of value added services that require QoS (e.g., IPTV) and (2) network convergence towards a unified IP-based architecture, for voice, image and data services. In this context, the limitations of existing QoS technologies emerge: it is currently difficult for an operator to guarantee that its network can offer a specific level of service. Furthermore, it is very difficult to ensure a consistent treatment of end-to-end QoS-sensitive flow that cross networks controlled by several operators. Indeed, the control on such traffic flows is shared between all the traversed operators. In the thesis, we have studied these issues. Specifically, we have addressed the problems of routing and dynamic traffic engineering at inter-domain level. We have proposed several algorithmic solutions to compute paths subject to multiple performance constraints. Analytical studies and simulations show that our algorithms are efficient and scalable. Finally, we have integrated our solutions into an architecture that is under ongoing standardization by the IETF and we have studied the protocol adaptations required for the deployment of our algorithms. Our work represents an important step towards more effective inter-domain traffic management in traffic engineered networks.; La problématique de la fourniture de qualité de service (QoS) dans les réseaux Internet connaît un regain d'intérêt engendré par deux phénomènes : (1) la croissance des services à valeur ajoutée qui demandent de la QoS (e.g., IPTV) et (2) la convergence des réseaux vers une architecture unifiée, basée sur IP, pour les services de voix, d'image, et de données. Dans ce contexte, des limitations des technologies actuelles de QoS apparaissent : il est actuellement difficile pour un opérateur de garantir les niveaux de service que son réseau peut offrir. Par ailleurs, il est très difficile de garantir un traitement cohérent de bout en bout pour les flux sensibles à la QoS et qui traversent les réseaux de plusieurs opérateurs. En effet, le contrôle de ces flux d'information est partagé entre tous les opérateurs traversés. Dans la thèse, nous avons étudiés ces différents problèmes. Nous nous sommes plus spécifiquement penchés sur les problèmes de routage et d'ingénierie dynamique de trafic au niveau inter-domaine. Nous avons proposés plusieurs solutions algorithmiques pour permettre de calculer des chemins soumis à plusieurs contraintes de performance. Des études analytiques et par simulations montrent que nos algorithmes sont efficaces et extensibles. Enfin, nous les avons intégrés dans une architecture récemment standardisée à l'IETF et avons étudié les adaptations protocolaires requises pour leur déploiement. Nos contributions représentent un pas important vers une gestion plus efficace du trafic inter-domaine dans les réseaux à ingénierie de trafic.

Transport Policy Implementation And Outcomes:The Case of Yaounde in the 1990s

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

This thesis examines the implementation and outcomes of market friendly reforms in urban public transport in the city of Yaonde in Cameroon in the 1990s under auspices and pressure from Bretton Woods Institutions in favour of the new development doctrine that preached minimal state. It seeks to expalin why certain policy measures were implemented and others not. The lessons drawn from this case study show how the particular governance context exerts influence on public policy.

Intermodal Barge Transport: Network Design, Nodes and Competitiveness

Scipedia content — Tue, 26 Jan 2021 13:19:24 +0100

The thesis addresses the opportunities and conditions to increase the market share of intermodal barge transport in Northwest Europe. In particular, it focuses on strategies to improve the performances of the different links of the intermodal transport chain: the barge transport services, the transhipment at terminals and pre- and post-truck haulage operations. The thesis shows that the development of more complex barge transport services, implemented for instance in collection/distribution-, trunk-feeder- and hub-and-spoke service networks, can improve the market position of barge transport in the hinterland transport of containers and enables to open up new markets for intermodal barge transport. However, to support the well-functioning of these service networks appropriate terminal and transhipment concepts are needed. Basically there are three ‘locations’ in the network where tailor-made barge handling innovations are needed: (1) in the seaport, (2) in the capillaries of the waterway network and (3) in strategically located inland nodes, e.g. to support hub-and-spoke networks. In pre- and post-truck haulage, which has a relatively large share in the total chain costs, the challenge is to improve the organisation of these hauls through combining loaded trips. In developing business areas close to waterways favourable conditions are created for efficient pre- and post-haulage and this contributes to improving the competitiveness of intermodal barge transport.

New business models for electric cars: A holistic approach

Scipedia content — Mon, 25 Jan 2021 20:09:05 +0100

Climate change and global resource shortages have led to rethinking traditional individual mobility services based on combustion engines. As the consequence of technological improvements, the first electric vehicles are now being introduced and greater market penetration can be expected. But any wider implementation of battery-powered electrical propulsion systems in the future will give rise to new challenges for both the traditional automotive industry and other new players, e.g. battery manufacturers, the power supply industry and other service providers. Different application cases of electric vehicles are currently being discussed which means that numerous business models could emerge, leading to new shares in value creation and involving new players. Consequently, individual stakeholders are uncertain about which business models are really effective with regard to targeting a profitable overall concept. Therefore, this paper aims to define a holistic approach to developing business models for electric mobility, which analyzes the system as a whole on the one hand and provides decision support for affected enterprises on the other. To do so, the basic elements of electric mobility are considered and topical approaches to business models for various stakeholders are discussed. The paper concludes by presenting a systemic instrument for business models based on morphological methods.

Rigorous Screening Technology for Identifying Suitable CO2 Storage Sites II

Scipedia content — Mon, 25 Jan 2021 19:58:36 +0100

This report serves as the final technical report and users manual for the 'Rigorous Screening Technology for Identifying Suitable CO2 Storage Sites II SBIR project. Advanced Resources International has developed a screening tool by which users can technically screen, assess the storage capacity and quantify the costs of CO2 storage in four types of CO2 storage reservoirs. These include CO2-enhanced oil recovery reservoirs, depleted oil and gas fields (non-enhanced oil recovery candidates), deep coal seems that are amenable to CO2-enhanced methane recovery, and saline reservoirs. The screening function assessed whether the reservoir could likely serve as a safe, long-term CO2 storage reservoir. The storage capacity assessment uses rigorous reservoir simulation models to determine the timing, ultimate storage capacity, and potential for enhanced hydrocarbon recovery. Finally, the economic assessment function determines both the field-level and pipeline (transportation) costs for CO2 sequestration in a given reservoir. The screening tool has been peer reviewed at an Electrical Power Research Institute (EPRI) technical meeting in March 2009. A number of useful observations and recommendations emerged from the Workshop on the costs of CO2 transport and storage that could be readily incorporated into a commercial version of the Screening Tool in a Phase III SBIR.

Responding to Increasing Port-related Freight Volumes

Scipedia content — Mon, 25 Jan 2021 19:49:11 +0100

Rapid growth in international trade over the last two decades has generated both benefits and costs. Costs have become increasingly visible in metropolitan areas -- growing congestion, air pollution – and local communities are demanding solutions. Congestion and air pollution associated with increased international trade have become so severe in the Los Angeles region that port-related trade is facing increased regulation by both state and local agencies. Historically US ports have been remarkably autonomous. Their role as economic development engines is wellrecognized by local leaders. Thus recent regulatory efforts represent a significant change in public policy. This report begins with an overview of trends in port-related trade and its impacts on US metropolitan areas, and discusses changing public perceptions of port-related trade as impacts have increased. Using Southern California as a case study, the report examines responses by the ports, terminal operators, and allied industries to a changed regulatory regime. Two examples are discussed in detail: 1) a state regulation requiring appointments or extended hours at terminal gates, and 2) the OFFPeak extended gate hours program. We use a political economy framework to explain outcomes. I describe the main economic actors and their competitive positions, and we explain the key aspects of the US regulatory system affecting these actors. Those with significant market power within the international trade supply chain were successful in staving off several regulatory attempts to force changes in operating practices. When regulations were imposed, they were able to structure responses to protect their economic interests. Results suggest that “dominant actors” – ports, terminal operators, steamship lines, and their major clients – will continue to be a strong influence in efforts to solve trade-related environmental problems.

Mongolia : Southern Gobi Regional Environmental Assessment

Scipedia content — Mon, 25 Jan 2021 19:42:00 +0100

The primary objective of the Southern Gobi Regional Environmental Assessment (REA) is to provide guidance for sustainable management of environmental resources in the future development of the Southern Gobi Region (SGR), development that will be led by rapid expansion of mining. The REA defines two development scenarios-a base-case and a high case-and explores their direct and indirect impacts on the natural environment, taking into account the opportunities, constraints, and vulnerabilities of the Gobi natural systems; the individual and cumulative direct environmental impacts and potential indirect impacts of the planned development; and, at a general level, the institutional capacity to manage the impacts. The REA target audience includes government officials at central, regional, and local levels; private sector investors and the consultants who are engaged for project design and environmental impact assessment; development finance organizations; and Mongolian civil society. This report was discussed in draft form at stakeholder workshops held in Ulaanbaatar and Dalanzagdad in April 2009 and has been revised to reflect comments received. Thanks are due to all those who joined those discussions. The report draws on information from workshops held in Mongolia, in May, September, and October 2008, and a field mission to the Southern Gobi Region in November 2008. Other information was obtained from various mining companies in Mongolia including Ivanhoe mines Mongolia, Inc., and its consultant Eco Trade; Rio Tinto; Energy Resources LLC; and South Gobi Sands.

Connecting to Compete 2010 : Trade Logistics in the Global Economy--The Logistics Performance Index and Its Indicators

Scipedia content — Mon, 25 Jan 2021 19:30:44 +0100

This report presents the findings of the second edition of Connecting to Compete, a report on the new dataset for the 2010 Logistics Performance Index (LPI) and its component indicators. Based on a worldwide survey of global freight forwarders and express carriers, the LPI is a benchmarking tool developed by the World Bank that measures performance along the logistics supply chain within a country. The index can help countries identify challenges and opportunities and improve their logistics performance. The World Bank conducts the survey every two years. The 2010 LPI also provides a snapshot of selected performance indicators in nearly 130 countries, including expanded information on the time, cost, and reliability of import and export supply chains, infrastructure quality, performance of core services, and the friendliness of trade clearance procedures. The 2010 LPI and its indicators encapsulate the firsthand knowledge of movers of international trade, collected amid the economic turmoil of 2009. This information is relevant for policymakers and the private sector seeking to identify priorities for reform agendas. Findings include the following. First, except in high-income countries, the availability and quality of trade-related infrastructure is a major constraint to performance, but the specific priorities tend to vary across countries. Second, efficient border management and coordination of the various agencies involved in border clearance is increasingly important. Third, a major challenge for the international community is how to help the lowest performing countries benefit from an increasingly open global trading system.

Vehicle routing with stochastic time-dependent travel times

Scipedia content — Mon, 25 Jan 2021 19:12:49 +0100

Assigning and scheduling vehicle routes in a stochastic time-dependent environment is a crucial management problem. The assumption that in a real-life environment everything goes according to an a priori determined static schedule is unrealistic. Our methodology builds on earlier work in which the traffic congestion is captured in an analytical way using queueing theory. The congestion is then applied to the VRP problem. In this paper, we introduce the variability in traffic flows into the model. This allows for an evaluation of the routes based on the uncertainty involved. Different experiments show that the risk taking behavior of the planner can be taken into account during optimization. As more weight is given to the variability component, the resulting optimal route will take a slightly longer travel time, but will be more reliable. We propose a powerful objective function that is easily implemented and that captures the trade-off between the average travel time and its variance. The evaluation of the solution is done in terms of the 95th-percentile of the travel time distribution (assumed to be lognormal), which reflects well the quality of the solution in this stochastic time-dependent environmen

Online Delay Management

Scipedia content — Mon, 25 Jan 2021 18:58:38 +0100

We present extensions to the Online Delay Management Problem on a Single Train Line. While a train travels along the line, it learns at each station how many of the passengers wanting to board the train have a delay of delta. If the train does not wait for them, they get delayed even more since they have to wait for the next train. Otherwise, the train waits and those passengers who were on time are delayed by delta. The problem consists in deciding when to wait in order to minimize the total delay of all passengers on the train line. We provide an improved lower bound on the competitive ratio of any deterministic online algorithm solving the problem using game tree evaluation. For the extension of the original model to two possible passenger delays delta_1 and delta_2, we present a 3-competitive deterministic online algorithm. Moreover, we study an objective function modeling the refund system of the German national railway company, which pays passengers with a delay of at least Delta a part of their ticket price back. In this setting, the aim is to maximize the profit. We show that there cannot be a deterministic competitive online algorithm for this problem and present a 2-competitive randomized algorithm.

PROLOGUE Deliverable 2.2 Methodological and organizational issues and requirements for ND studies

Scipedia content — Mon, 25 Jan 2021 18:57:31 +0100

Naturalistic driving observation is a relatively new method for studying road safety issues, a method by which one can objectively observe various driver- and accident related behaviour. Typically, participants get their own vehicles equipped with some sort of data logging device that can record various driving behaviours such as speed, braking, lane keeping/variations, acceleration, deceleration etc., as well as one or more video cameras. In this way normal drivers are observed in their normal driving context while driving their own vehicles. Optimally, this allows for observation of the driver, vehicle, road and traffic environments and interaction between these factors. The main objective of PROLOGUE is to demonstrate the usefulness, value, and feasibility of conducting naturalistic driving observation studies in a European context in order to investigate traffic safety of road users, as well as other traffic related issues such as eco-driving and traffic flow/traffic management. The current deliverable describes the methodological issues related to naturalistic driving studies. It describes the experimental procedures, variables to be measured, experimental design, statistical analysis methods, organizational issues and legal and ethical issues for naturalistic studies. Maximal use is made of the extensive knowledge and experience that comes from the EU projects FESTA and EuroFOT, the 100car study and the SHRP2 preparatory safety studies.

Potential Climate Change Mitigation Opportunities in the Transport Sector in Vietnam

Scipedia content — Mon, 25 Jan 2021 18:43:18 +0100

Vietnam's transport sector plays an important role in its socioeconomic development. Passenger transport helps meets daily needs and contributes significantly to tourist service development while freight transport helps meet the country's demand for delivery of raw materials and of semi-finished products to production facilities and for transport of finished products to consumers. With the overall growth in transport in the country, each of the main forms of transport (road, railway, aviation, inland waterways and maritime) are currently increasing the total fuel use for transport and as a result overall greenhouse gas emissions. In addition to the mix of transport modes used, the major factors affecting the impact of this growth on current and future greenhouse gases from each mode of transport are the quality and quantity of the vehicles and supporting infrastructure and the type of fuels used and their efficiency. The following sections evaluate the infrastructure and fuel use of each of the modes of transport (sections 1.1-1.5), the current and projected greenhouse gas emissions from the sector and the reasons for this (section 2), and typologies of interventions that can reduce the emissions from the sector (section 3).

State of the Art on Alternative Fuels in Aviation. Executive summary

Scipedia content — Mon, 25 Jan 2021 18:30:05 +0100

This paper summarises the findings from the SWAFEA preliminary state of the art study. It covers trends in aspects of future air transport, potential candidate fuels and associated feedstock along with sustainability and economical issues relevant for alternative fuels in aviation..

Critical success factors for implementing road charging systems

Scipedia content — Mon, 25 Jan 2021 18:28:59 +0100

Road user charging is used as an 'umbrella' term to describe a wide range of applications of pricing roads and infrastructure. Road user charging includes a number of charging measures that governments and other road owners use to: i) finance new or maintain existing road infrastructure ii) manage traffic (e.g. reduce congestion) iii) minimise environmental impacts of transport iv) internalise the external costs of road transport caused, e.g., by pollution and noise emissions. Historically, the common approach to charging for road use is some form of general taxation rather than differentiated road user charging. Road user charging has long been proposed as an efficient and equitable method to pay for road use and to fund road infrastructure projects. However, there is an important distinction between charging for revenue generation purposes as opposed to pricing roads to provide congestion relief. The two basic objectives, revenue generation and congestion management, differ in several ways, as shown in the following table.

Interurban Passenger Transport

Scipedia content — Mon, 25 Jan 2021 18:27:13 +0100

The future of interurban public transport will be significantly affected by public sector decisions concerning investment in infrastructure, particularly the construction of new high-speed rail lines in medium-distance corridors where cars, buses, airplanes and conventional trains are the competing modes of transport. The distribution of traffic between the alternative modes of transport depends on the generalized prices, which fundamentally consist of costs, time and government's pricing decisions. High-speed rail investment, financed by national governments and supranational institutions such as the European Union (EU), has drastically changed the previous equilibrium in the affected corridors. This paper discusses the economic rationale for allocating public money to the construction of high-speed rail infrastructure and how the present institutional design affects the selection of projects by national and regional governments, with deep long-term effects in these corridors and beyond.

In-vehicle and site-based observations of vehicles and cyclists. A small-scale ND study in the Netherlands. PROLOGUE Deliverable D3.4

Scipedia content — Mon, 25 Jan 2021 18:25:28 +0100

The main objective of the project PROLOGUE (PROmoting real Life Observations for Gaining Understanding of road user behaviour in Europe) is to explore the feasibility and usefulness of a large-scale European naturalistic driving observation study. The work described in this deliverable focused on the feasibility of using and combining two observation methods, site-based observation and in-vehicle observation, for naturalistic driving analysis. In this study the strengths and weaknesses of each method were analyzed and the differences between measures that were calculated by both methods were compared to consider the combined results. The two different observation methods studied the interaction between car drivers turning right and cyclists going straight at an intersection, which was equipped with cameras. For the site-based study one camera was used that had a bird’s eye view on the intersection. The video data were processed manually and automatically. The results of the two ways of analysis were compared. The instrumented cars were equipped with a data acquisition system (DAS) and sensors including a GPS logger and a camera. The results of the site-based observations showed that the manual processing seemed to be more accurate than the automatic processing. However, the processing time was much larger for manual analysis. Having a top view camera or more cameras with different viewpoints could improve the accuracy of automatic processing by providing the ability to detect the sizes of the road users and therefore the road user type. The in-vehicle measurement showed that drivers show different driving behaviour when making the right turn manoeuvre from a halted situation compared to a non-halted situation. This implies that drivers adapt their behaviour and compensate for the more dangerous situation by driving slower and looking more often. The results of the speed measure comparison between the site-based and in-vehicle study showed that the average speeds for both studies were similar. However, the speed profile that was measured in the in-vehicle study was less smooth than the speed pattern that was derived in the site-based study. This is explained by the noisy GPS signal on which the in-vehicle speeds are based. The value of combining the two observation methods is twofold. At first it offers the opportunity to enrich the information from one study with complementary observations from the other study. Secondly, it offers the opportunity to validate measures from the individual studies. This study showed that each type of study has its unique values. From in-vehicle data it is possible to look in detail at the driving behaviour of the participants over time and in different natural situations. The video data allows looking over the shoulder of the driver and observer where drivers are looking or what they are paying attention to. By analyzing their glancing behaviour, we know when and how often drivers look at other vulnerable road users to estimate their position and speed and to be able to anticipate. For a future large scale naturalistic driving study it could be valuable to add a number of sites with site-based observation. Two main areas are identified that would benefit from these complementary observations. One research area is when studying the interaction between drivers and vulnerable road users. Another research area that would benefit from the complementary observations is research questions related to infrastructure – as these are by nature related to a specific site like an intersection, a lane merge or a roundabout. The site-based observation allows to observe the traffic flow, the in-vehicle observation could add (for the overlapping cases) information on looking behaviour or other in-vehicle behaviours as well as additional vehicle data like accelerations.

Confronting "Death on Wheels" : Making Roads Safe in Europe and Central Asia

Scipedia content — Mon, 25 Jan 2021 18:23:35 +0100

This report provides an overview of the challenges and opportunities in addressing road safety in the Europe and Central Asia (ECA) region. It presents information on the size, characteristics, and causes of the problem; presents evidence on the effectiveness of measures that countries world-wide have adopted to improve road safety; briefly describes current international road safety policy; and discusses a range of strategies and actions that could be undertaken by the World Bank in coordination and partnership with the World Health Organization (WHO), multilateral development banks, other international agencies and donors, as well as with private and civil society institutions. A primary audience of this report is internal-particularly managers and staff of the World Bank working in the transport, health, education, and governance sectors, to raise awareness about the multisectoral nature of the road safety challenge and of effective options to address it. It proposes ways that the World Bank might engage more to support ECA countries in tackling this issue, working in partnership with other international agencies and donors. The secondary audience is external policymakers, senior analysts, program managers, and their advisers in the governments of ECA countries, private sector officials, and civil society and international organizations working in this field. The goal is to support discussion on appropriate choices and instruments for advancing the road safety agenda as a top development priority over the short and medium term.

The Economics of CO2 Emissions Trading for Aviation

Scipedia content — Mon, 25 Jan 2021 18:11:22 +0100

There has been a growing interest in the environmental impact of aviation, both in terms of noise and aircraft engine emissions. Discussions have included both mitigation measures and methods of internalisation of these environmental costs also described as the principle of polluter pays. This paper focuses on CO2 emissions from aircraft engines, which have both local and climate change implications, and where the emphasis of most recent discussions has centred. These have taken place at an international, regional and local level.

Making Infrastructure Work for Women and Men : A Review of World Bank Infrastructure Projects (1995-2009)

Scipedia content — Mon, 25 Jan 2021 18:10:12 +0100

This report provides a gender review of a decade and a half of World Bank infrastructure lending for 1,246 projects. The objective of this review is to assess the status of and trends in gender integration in the World Bank infrastructure portfolio, and to establish a baseline for monitoring and enhancing gender integration in line with commitments made for the 2006 gender action plan. The portfolio review reveals important progress on gender integration in infrastructure operations. While an average of 14 percent of infrastructure projects in 1995 applied some attention to gender concerns in 1995, this climbed to 36 percent by 2009. The global average, moreover, hides large strides made over time in four regions. In 2009, East Asia and the Pacific, Middle East and North Africa, South Asia, and Africa all included gender concerns in the design of at least 50 percent of their infrastructure projects. Hard work remains in consolidating and extending the gains in gender coverage across the infrastructure portfolio. This will require stronger management commitment, concerted efforts, a plan with targets to achieve sustainable results, resources, specialist staffing, and capacity enhancement of staff. The portfolio review repeatedly found that supporting gender equality and women's empowerment in infrastructure operations have large benefits for the communities; the actions not only increased women's opportunities but also enhanced project effectiveness, efficiency, and sustainability.

Climate for Collaboration: Analysis of US and EU Lessons and Opportunities in Energy and Climate Policy

Scipedia content — Mon, 25 Jan 2021 18:07:19 +0100

deepening of cooperation between the United States and the European Union requires mutual trust, and understanding of current policies, challenges and successes. Through providing such understanding among policymakers, industry and other stakeholders in both economies, opportunities for transatlantic cooperation on climate change and energy policy emerge. This paper sets out by discussing the environmental, legislative, and economic contexts of the EU and US as related to climate. This context is essential to understanding how cap-and-trade, renewable energy and sustainable transportation policies have taken shape in the EU and the US, as described in Chapter 3.1. For each of these policies, a barrier analysis and discussion is provided. Chapter 4 builds off this improved understanding to listobservations and possible lessons learned. The paper concludes with recommendations on topics where EU and US interests align, and where further cooperation could prove beneficial.

Transport outlook 2009: Globalisation, crisis and transport

Scipedia content — Mon, 25 Jan 2021 17:34:09 +0100

This second ITF Transport Outlook continues building towards a full-fledged Transport Outlook, building upon the first Outlook (JTRC, 20081). The 2008 Outlook investigated the relation between expected GDP evolution and the demand for road transport, pointing out that transport demand and CO2-emissions could well turn out higher than commonly assumed given the projected evolution of GDP, and underlining the potential of improvements of fuel efficiency in controlling CO2-emissions from road transport. These topics were developed further in the “50 by 50 Global Fuel Economy Initiative”.2 The 2009 Outlook considers two themes that are closely linked to the International Transport Forums’s them for the 2009 meeting in Leipzig: Transport for a global economy – Challenges and opporturnities in the downturn. First, in Section 2, we focus on the evolution of GDP itself and how this evolution interacts with transport demand and investments in transport infrastructure. The analysis is a first brush at gauging the potential impacts of the economic and financial crisis. Specifically, we consider (a) the impact of the aggregate demand shock on the evolution of global GDP, (b) the need and potential for a rebalancing of global growth patterns, with their implications for trade and transport demand, and (c) the consequences of the widening funding gap for transport infrastructure investments. Second, in Sections 3 through 5, we discuss projections of the demand for road transport, aviation, and maritime transport. For road transport, more modest global growth leads to slower growth of the vehicle stock and of CO2-emissions, but the basic messages of the 2008 Outlook continue to hold. For aviation, we attempt to disentangle the effects of economic growth and of increased openness of markets on volume growth, and find that the latter is an important growth factor. For maritime transport, the focus is on likely development patterns and how they could be affected by the crisis, and how this does (not) affect recommendations for dealing with expected CO2-emissions.

Tender prices in local bus transport in Germany - an application of alternative regression techniques

Scipedia content — Mon, 25 Jan 2021 17:30:05 +0100

Competitive tendering of local bus services in Germany has received increased attention. Employing Seemingly Unrelated Regression analyses, we observe that prices have regionally varying determinants; for example, while prices throughout most of the federal state of Hesse increase over time, prices in the Munich area decrease. Optimisation of bus utilisation in general has a cost-decreasing impact, confirming that public transport authorities can reduce prices via adequate transport planning. Furthermore, Stochastic Frontier Analysis shows that tender prices in Hesse are slightly less efficient. Moreover we conclude that the public transport authority's experience has an efficiency-increasing impact which supports the introduction of overarching authorities.

Competitive Cities and Climate Change

Scipedia content — Mon, 25 Jan 2021 17:25:17 +0100

Cities are part of the climate change problem, but they are also a key part of the solution. This report offers a comprehensive analysis of how cities and metropolitan regions can change the way we think about responding to climate change. Cities consume the vast majority of global energy and are therefore major contributors of greenhouse gas emissions. At the same time, the exposed infrastructure and prevalent coastal location of many cities makes them common targets for climate change impacts such as sea level rise and fiercer storms. This report illustrates how local involvement through ?climate-conscious? urban planning and management can help achieve national climate goals and minimise tradeoffs between environmental and economic priorities. Six main chapters analyse the link between urbanisation, energy use and CO2 emissions; assess the potential contribution of local policies in reducing global energy demand and the trade-offs between economic and environmental objectives at the local scale; discuss complementary and mutually reinforcing policies such as the combination of compact growth policies with those that improve mass transit linkages; and evaluate a number of tools, including the ?greening? of existing fiscal policies, financing arrangements to combat climate change at the local level, and green innovation and jobs programmes. One of the main messages of this report is that urban policies (e.g. densification or congestion charges) can complement global climate policies (e.g. a carbon tax) by reducing global energy demand, CO2 emissions and the overall abatement costs of reducing carbon emissions. To inform the groundswell of local climate change action planning, the report highlights best practices principally from OECD member countries but also from certain non-member countries.

Acoustic resonance in a reservoir-pipeline-orifice system

Scipedia content — Mon, 25 Jan 2021 17:16:39 +0100

The fundamentals of oscillating flow in a reservoir-pipe-orifice system are revisited in a theoretical study related to acoustic resonance experiments carried out in a large-scale pipeline. Four different types of system excitation are considered: forcing velocity, forcing pressure, linear oscillating resistance and nonlinear oscillating resistance. Analytical solutions are given for the periodic responses to the first three excitations. Analytical and numerical results for the large-scale pipeline are presented and some peculiarities are discussed. Key words: Hydraulic transients; Acoustic resonanceImpedance; Orifice; Rotating valve; Analytical solution.

Modelski pristop k zagotavljanju kakovosti javnega potniškega prometa

Scipedia content — Mon, 25 Jan 2021 17:14:42 +0100

Modern approach to transportation system research is based on the system theory. System analysis is relevant. Constant transportation technique and technology development caused by the need of conformation to the new market conditions is the basis for such an approach. The model approach for resolving the problems of public passenger transport is provided in a scientific report. The model of quality of passenger transport comprises the submodels which define relevant measures for the provision of passenger transport quality. The synthesis of sub-model for adoption of quality standards, submodel of passenger demands, submodel of operation safety and security and economic submodel construct the model of quality of public passenger transport (PPT). Its evaluation has been carried out using SWOT analysis. Sodobni pristopi k raziskovanju prometnega sistema javnega potniškega prometa temeljijo na upoštevanju teorije sistemov posledica česar je sistemski pristop k obravnavanju problematike. V slednje nas usmerja predvsem nenehen razvoj tehnike in tehnologije proizvodnje prometnih storitev, ki se mora prilagajati novim tržnim pogojem poslovanja. V znanstvenem prispevku je prikazan modelski pristop k reševanju javnega potniškega prometa. Model kakovosti javnega prevoza temelji na podmodelih, ki določajo potrebne ukrepe za zagotavljanje kakovosti javnega prevoza. Sinteza podmodela osvajanja standardov, podmodela povpraševanja po javnem prevozu, podmodela varnosti obratovanja in ekonomskega podmodela vzpostavlja model kakovosti javnega potniškega prometa, kate-rega vrednotenje je narejeno s pomočjo SWOT analize.

Assessing Barriers to Trade in Services in the MENA Region

Scipedia content — Mon, 25 Jan 2021 17:07:15 +0100

This paper aims to assess barriers to service provision in the financial, telecom, and transport sectors of selected MENA countries, including both trade and domestic restrictions. The analysis is focused on computation of aggregate and modal trade restrictiveness indexes (TRIs) by sector, drawing on information gathered from detailed questionnaires and country reports prepared by local consultants. The conclusions highlight that significant regulatory reforms have taken place in the service sectors of Egypt, Jordan, Lebanon and Morocco over the last decade, but that a broad range of restrictions still remain. The most significant change in these service sectors has been the lifting or softening of the constraints imposed on foreign equity participation. Reforms, however, have had varying degrees of impact on market structure depending on the country and the sector.

Water hammer and column separation due to accidental simultaneous closure of control valves in a large scale two-phase flow experimental test rig

Scipedia content — Mon, 25 Jan 2021 17:02:52 +0100

A large-scale pipeline test rig at Deltares, Delft, The Netherlands has been used for filling and emptying experiments. Tests have been conducted in a horizontal 250 mm diameter PVC pipe of 258 m length with control valves at the downstream and upstream ends. This paper investigates the accidental simultaneous closure of two automatic control valves during initial testing of the test rig. The simultaneous closure of both valves has induced upsurge and downsurge at the same time. Large water hammer and column separation have caused failure of pipe supports and leakage at pipe joints. The incident was caused by a fault in an electronic conversion box due to power failure. Afterwards the downstream end automatic valve has been modified to a manually operated valve to avoid the accidental simultaneous closure of the valves. The accidental transient event has been fully recorded with pressures, flow rates and water levels. The measurements of the accident are presented, analyzed and discussed in detail. Photographs show the damages to the system.

Sino-Singapore Tianjin Eco-City : A Case Study of an Emerging Eco-City in China

Scipedia content — Mon, 25 Jan 2021 16:30:50 +0100

China is experiencing rapid and large scale urbanization, and the resulting local and global urban environmental challenges are unprecedented. The Chinese Government has fully recognized these challenges and is aiming to promote more sustainable urbanization in line with the objectives of the eleventh five year plan, which calls for 'building a resource-conserving and environmentally friendly society'. Various initiatives are being pursued to support this objective, both at the national and local levels. At the local level, cities have responded by developing 'eco-cities', which aim to promote a more sustainable urbanization model. More than one hundred eco-city initiatives have been launched in recent years. One such initiative is the Sino-Singapore Tianjin eco-city. The purpose of this report is to review the Sino-Singapore Tianjin Eco-City (SSTEC) project from a comprehensive perspective with a view to achieving the following principal objectives: (i) create a detailed knowledge base on the project; (ii) provide policy advice on key issues, especially those related to the Global Environment Facility (GEF) project; (iii) estimate SSTEC's Greenhouse Gas (GHG) emission reduction potential; and (iv) contextualize the project among the broader ecological urban development initiatives in China. Broadening the World Bank's engagement beyond the GEF was assessed as important given the project's complexity, and its potential to shed light on China's sustainable urban development challenge

Development of the Write Process for Pipeline-Ready Heavy Oil

Scipedia content — Mon, 25 Jan 2021 16:30:02 +0100

Work completed under this program advances the goal of demonstrating Western Research Institute's (WRI's) WRITE{trademark} process for upgrading heavy oil at field scale. MEG Energy Corporation (MEG) located in Calgary, Alberta, Canada supported efforts at WRI to develop the WRITE{trademark} process as an oil sands, field-upgrading technology through this Task 51 Jointly Sponsored Research project. The project consisted of 6 tasks: (1) optimization of the distillate recovery unit (DRU), (2) demonstration and design of a continuous coker, (3) conceptual design and cost estimate for a commercial facility, (4) design of a WRITE{trademark} pilot plant, (5) hydrotreating studies, and (6) establish a petroleum analysis laboratory. WRITE{trademark} is a heavy oil and bitumen upgrading process that produces residuum-free, pipeline ready oil from heavy material with undiluted density and viscosity that exceed prevailing pipeline specifications. WRITE{trademark} uses two processing stages to achieve low and high temperature conversion of heavy oil or bitumen. The first stage DRU operates at mild thermal cracking conditions, yielding a light overhead product and a heavy residuum or bottoms material. These bottoms flow to the second stage continuous coker that operates at severe pyrolysis conditions, yielding light pyrolyzate and coke. The combined pyrolyzate and mildly cracked overhead streams form WRITE{trademark}'s synthetic crude oil (SCO) production. The main objectives of this project were to (1) complete testing and analysis at bench scale with the DRU and continuous coker reactors and provide results to MEG for process evaluation and scale-up determinations and (2) complete a technical and economic assessment of WRITE{trademark} technology to determine its viability. The DRU test program was completed and a processing envelope developed. These results were used for process assessment and for scaleup. Tests in the continuous coker were intended to determine the throughput capability of the coker so a scaled design could be developed that maximized feed rate for a given size of reactor. These tests were only partially successful because of equipment problems. A redesigned coker, which addressed the problems, has been build but not operated. A preliminary economic analysis conducted by MEG and an their engineering consultant concluded that the WRITE{trademark} process is a technically feasible method for upgrading bitumen and that it produces SCO that meets pipeline specifications for density. When compared to delayed coking, the industry benchmark for thermal upgrading of bitumen, WRITE{trademark} produced more SCO, less coke, less CO{sub 2} per barrel of bitumen fed, and had lower capital and operating costs. On the other hand, WRITE{trademark}'s lower processing severity yielded crude with higher density and a different product distribution for naphtha, light gas oil and vacuum oil that, taken together, might reduce the value of the SCO. These issues plus the completion of more detailed process evaluation and economics need to be resolved before WRITE{trademark} is deployed as a field-scale pilot.

International air passenger transport in the future

Scipedia content — Mon, 25 Jan 2021 16:29:17 +0100

The objective of this paper is relatively straightforward, suggesting “what international air passenger travel will look like in five, ten or fifteen years and why?” This requires answering two questions; what will be the principal determinants of the growth in international air travel and what impact will each of these drivers have on the growth rate? An imbedded question is does history have anything to teach us or are there new forces at work? Canvassing the current aviation trade press finds two schools of thought, one taking the position that this a deep recession but a recession nonetheless and once world economies start recovering air traffic will go back to the typical growth of 4-5 percent annually. A second school is less sanguine, taking the position that it will not be business as usual when economies stop sinking and move to recovery. Any economic recovery is going to involve fundamental changes in institutions, rethinking polices regarding government participation in economies and changes in economic leadership in the world. There is also the hydra of protectionism most prominent now in the US but certainly being practiced elsewhere, and what will happen to foreign ownership restrictions that prior to 2009 were being seen as hurting rather than helping world airlines. All of this will change international aviation going forward.

Deformacijska analiza cestnih mostov pri transportu izrednih tovorov v Sloveniji

Scipedia content — Mon, 25 Jan 2021 16:28:56 +0100

In August 1999 an exceptional transportation of two steamers of 666 tonnes was performed from the Port of Koper to the Nuclear power plant in Krško. The transport covered a distance of about 200km and represented one of the largest exceptional transports in Slovenia ever. Finding the best route represented one of the major issues, because the steamers had to cross more than 50 problematic sections and bridges, most of which have not been designed for such heavy loads. It was necessary to load-test almost all bridges on the route to determine whether those bridges need any extra supports or not. Consequently, a logistic operator has an important and indispensable role and becomes a co-modeller of logistic service. A deformation analysis or a polynomial interpolation of vertical displacements could also be used. Therefore, a laboratory load test of a concrete plate was made. The concrete plate was loaded with hydraulic cylinder PZ 100 with extensiometer up to 21kN. Every increase of load by 3kN was measured with Nikon Ser 800 total station. V Sloveniji je bilo potrebno avgusta 1999 iz Koprskega pristanišča do Nuklearne elektrarne Krško prepeljati dva uparjalnika teže 666 ton na relaciji dobrih 200 km, kar še danes predstavlja enega največjih tovorov, ki je kdajkoli potoval po Slovenji. Izbira najboljše poti je predstavljala zelo pomemben del transporta, saj sta uparjalnika na poti prečkala preko 50 problematičnih odsekov in mostov, ki za tako velike ob- remenitve večinoma niso predvideni. Tako je bilo potrebno določene premostitvene objekte testno obremenjevati, da bi ugotovili ali bodo obremenitev vzdržali in ali so za to potrebne dodatne ojačitve. Izredno vlogo pri tem mora odigrati logistični operator, saj je v vlogi moderatorja logistične storitve. Pomagali bi si lahko tudi z ustrezno deformacijsko analizo oz. interpolacijo vertikalnih pomikov s pomočjo polinomov. Za to je bil v laboratoriju izveden deformacijski obremenilni preizkus betonske plošče. Betonska plošča je bila obremenjevana s hidravličnim cilindrom PZ 100 z ekstenziometrom do sile 21 kN, ki je bil računalniško krmiljen. Izmerila se je vsaka dodatna obremenitev po 3 kN. Uporabljen je bil elektronski tahimeter znamke Nikon Ser. 800.

An Analysis Of Various Policy Instruments To Reduce Congestion, Fuel Consumption And CO2 Emissions In Beijing

Scipedia content — Mon, 25 Jan 2021 12:34:20 +0100

Using a nested multinomial logit model of car ownership and personal travel in Beijing circa 2005, this paper compares the effectiveness of different policy instruments to reduce traffic congestion and CO2 emissions. The study shows that a congestion toll is more efficient than a fuel tax in reducing traffic congestion, whereas a fuel tax is more effective as a policy instrument for reducing gasoline consumption and emissions. An improvement in car efficiency would also reduce congestion, fuel consumption, and CO2 emissions significantly; however, this policy benefits only richer households that own a car. Low-income households do better under the fuel tax policy than under the efficiency improvement and congestion toll policies. The congestion toll and fuel tax require the travel cost per mile to more than triple. The responsiveness of aggregate fuel and CO2 are, approximately, a 1 percent drop for each 10 percent rise in the money cost of a car trip.

Prospects for Research in Transport and Logistics on a Regional: Global Perspective (I: February 2009: İstanbul: Turkey)

Scipedia content — Mon, 25 Jan 2021 12:26:54 +0100

"International Conference on Prospects for Research in Transport and Logistics on a Global - Regional Perspective" has undertaken the challenge to host very important experts and practitioners of Transport and Logistics from a large spectrum of countries. In our opinion, the conference has fulfilled the purpose of establishing an International Society; "Eurasian and Eastern Mediterranean Institute of Transportation and Logistics Association (EMIT)" that is expected to have a very promising role in the Eurasian and Eastern Mediterranean countries. The purpose of the Association is to contribute to establishing and developing the exchange of research work between all parts of the world in all fields of transportation and logistics. This proceedings book consists of 13 chapters, grouping the contributed papers into the following categories: Global Issues in Logistics and Transportation (3 papers), Regional Issues in Logistics and Transportation (2 papers), Education and Training in Logistics and Transportation (2 papers), Supply Chain Management (3 papers), Sustainable Transport Policies, Traffic Engineering (4 papers), Evaluation of Public Policies, Network Models and Environment (4 papers), Contemporary Topics in Transport and Logistics (7 papers), Transport Planning and Economics (3 papers), Planning, Operations, Management and Control of Transport and Logistics (3 papers), Transport Modeling (5 papers), Freight Transportation and Logistics Management (7 papers), Transport and Land Use (3 papers), Transport Infrastructure and Investment Appraisal (2 papers) It can be readily seen from this volume of selected papers that all papers do elaborate on rather timely problems in the fields of expertise related to Transport and Logistics, which have a considerable global importance. TÃBÄ°TAK; DoÄuÅ Ãniversitesi ; UluslararasÄ± Nakliyeciler DerneÄi ; Ä°DO ; TÄ±rsan ; TÃ¼rk Hava YollarÄ± Committees, i -- Words of Welcome and Gratitude, ii -- Introduction, iii -- Chapter 1 Global Issues in Logistics and Transportation, 1 -- Potential to Reduce GHG through Efficient Logistic Concepts, 3 -- Werner Rothengatter -- A methodological framework for the evaluation and prioritisation of multinational transport projects: the Case of euro-asian transport linkages, 21 / Dimitrios TSAMBOULAS, Angeliki KOPSACHEILI -- Container port throughput performance - case study: Far east, north west european and mediterranean ports, 29 / Vesna DRAGOVIC-RADINOVIC, Branislav DRAGOVIC, Maja SKURIC, EmirÄIKMIROVlC and Ivan KRAPOVIC -- Chapter 2 Regional Issues in Logistics and Transportation, 35 -- Logistics service providers in turkey: A panel data analysis, 37 / Emel AKTAÅ, FÃ¼sun ÃLENGÄ°N, Berrin AÄARAN, Åule ÃNSEL -- Milestones in the process of survey preparation for the logistics sector: case study for Istanbul, Turkey, 43 / Evren POSACI, DarÃ§Ä±n AKIN -- Chapter 3 Education and Training in Logistics and Transportation, 51 -- Education in transport and logistics in an age of global economy, 53 / YÃ¼cel Candemlr -- The role of education and training in the supply chain sector, 59 / David Maunder -- Chapter 4 Supply Chain Management, 64 -- Modeling reverse flows in a closed -loop supply chain network, 67 / Vildan ÃZKIR, Ãnder ÃNDEMÄ°R and HÃ¼seyin BAÅLIGÄ°L -- Strategic analysis of green supply chain management practices in T urkish automotive industry, 73 / GÃ¼lÃ§in BÃYÃKÃZKAN and AliÅan ÃAPAN -- A new framework for port competitiveness: the network approach, 79 / Marcella DE MARTINO, Alfonso MORVILLO -- Chapter 5 Sustainable Transport Policies, Traffic Engineering, 87 -- Clean transport: innovative solutions to the creation of a more sustainable urban transport system, 89 / Ela BABALIK-SUTCLIFFE -- Effects of urban bottlenecks on highway traffic congestion: case study of Istanbul, Turkey, 95 / DarÃ§Ä±n AKIN and Mehtap ÃELÄ°K -- Establishing an effective training module for IMDG code in MET institutions, 105 / Kadir CICEK, Metin CELIK -- An investment decision aid proposal towards choice of container terminal operating systems based on information axioms, 109 / Metin CELIK, Selcuk CEBI -- Chapter 6 Evaluation of Public Policies, Network Models and Environment, 115 -- Possibilistic linear programming approach for strategic resource planning, 117 / ÃzgÃ¼r KABAK, FÃ¼sun ÃLENGÄ°N -- A structural equation model for measuring service quality in passenger transportation, 125 / G.Nilay YÃCENUR and Nihan ÃETÄ°N DEMÄ°REL -- Analysis of potential gain from using hybrid vehicles in public transportation, 133 / Ä°rem DÃZDAR and Ãzay ÃZAYDIN -- Optimization of e-waste management in Marmara region - Turkey, 141 / Ä°lke BEREKETLÄ°, MÃ¼jde EROL GENEVOIS -- Chapter 7 Contemporary Topics in Transport and Logistics, 147 -- Future prospects on urban logistic research, 149 / RosÃ¢rio MACÃRIO, Vasco REIS -- An analyze of relationship between container ships and ports development, 155 / Branislav DRAGOVIC, Vesna Dragovic-Radinovic, Dusanka Jovovic, Romeo Mestrovic and Emir Äikmirovic -- A holistic framework for performance measurement in logistics management, 161 / Yasemin Claire ERENSAL -- Heuristics for a generalization of tsp in the context of PCB assembly, 167 / Ali Fuat ALKAYA and Ekrem DUMAN -- Premium e-grocery: Exploring value in logistics integrated service solutions, 173 / BurÃ§in BOZKAYA, Ronan De KERVENOAEL and D. Selcen Ã. AYKAÃ -- T ravelers response to VMS in the Athens area, 179 / Athena TSIRIMPA and Amalia POLYDOROPOULOU -- Regional airports and local development: the challenging balance between sustainability and economic growth, 189 / RosÃ¢rio MACÃRIO and Jorge SILVA -- Chapter 8 Transport Planning and Economics, 195 -- How financial constraints and non-optimal pricing affect the design of public transport services, 197 / Sergio R. Jara-Diaz and Antonio Gschwender -- Revenue management for returned products in reverse logistics, 203 / Mesut KUMRU -- Intra-city bus planning using computer simulation, 211 / Reza AZIMI and Amin ALVANCHI -- Chapter 9 Planning, Operations, Management and Control of Transport and Logistics, 217 -- A review of timetabling and resource allocation models for light-rail transportation systems, 219 / Selmin D. ÃNCÃL, D. Selcen Ã. AYKAÃ, Demet BAYRAKTAR and Dilay ÃELEBÄ° -- An approach of integrated logistics HMMS model under environment constraints and an application of time scale, 225 / Fahriye Uysal, ÃmÃ¼r Tosun, Orhan KuruÃ¼zÃ¼m -- Freight transport planning with genetic algorithm based projected demand, 231 / Soner HALDENBILEN, Ozgur BASKAN, Huseyin CEYLAN and Halim CEYLAN -- Chapter 10 Transport Modeling, 239 -- Inverse model to estimate o-d matrix from link traffic counts using ant colony optimization, 241 / Halim CEYLAN, Soner HALDENBILEN, Huseyin CEYLAN, Ozgur BASKAN -- The impact of logistics on modelling commercial freight traffic, 251 / Ute IDDINK and Uwe CLAUSEN -- A comparative reviewof simulation-based behavior modeling for travel demand generation, 257 / Seda YanÄ±k, Mehmet TanyaÅ -- An efficiency analysis of turkish container ports using the analytic network process, 269 / Senay OÄUZTÄ°MUR, Umut RÄ±fat TUZKAYA -- A multi-objective approach to designing a multicommudity supply chain distribution network with multiple capacities, 277 / Gholam Reza Nasiri, Hamid Davoudpour and B.Karimi -- Chapter 11 Freight Transportation and Logistics Management, 283 -- Evaluation of turkeyâs freight transportation, 285 / Burcu KULELÄ° PAKand BaharSENNAROÄLU -- Short sea shipping, intermodality and parameters influencing pricing policies in the Mediterranean region: The Italian context, 291 / Monica GROSSO, Ana-Rita LYNCE, Anne SILLA, Georgios K. VAGGELAS -- Relevant strategic criteria when choosing a container port - the case of the port of Genoa, 299 / Monica Grosso, Feliciana Monteiro -- Determination of optimum fleet size and composition - A case study of retailer in Thailand, 307 / Terdsak RONGVIRIYAPANICH and Kawee SRIMUANG -- New container port development: forecasting future container throughput, 313 / Dimitrios TSAMBOULAS, Panayota MORAITI -- Sea port hinterland flows and opening hours: the way forward to make them match better 319 / Marjan BEELEN, Hilde MEERSMAN, Evy ONGHENA, Eddy VAN DE VOORDE and Thierry VANELSLANDER -- International road freight transport in Germany and the Netherlands driver costs analysis and French perspectives, 327 / Laurent GUIHERY -- Chapter 12 Transport and Land Use, 335 -- Land rent and new transport infrastructure: How to manage this relationship?, 337 / Elena SCOPEL -- Effects of pavement characteristics on the traffic noise levels, 345 / Aybike ONGEL and John HARVEY -- Fuzzy medical waste disposal facility location problem, 351 / YeÅim KOP, MÃ¼jde EROL GENEVOIS and H. Ziya ULUKAN -- Chapter 13 T ransport Infrastructure and Investment Appraisal, 357 -- Agentsâ behavior in financing Italian transport infrastructures, 359 / Paolo BERIA -- Free trade agreements in the mediterranean region: a box-cox analysis, 367 / Matthew KARLAFTIS, Konstantinos KEPAPTSOGLOU and Dimitrios TSAMBOULAS

Allocating functions to human and algorithm in scheduling

Scipedia content — Mon, 25 Jan 2021 12:24:18 +0100

An important part of Advanced Planning Systems are algorithms. When algorithms are applied, the task is automated as much as possible. However, the human that is supposed to use the algorithm is generally ignored during the development process. As a consequence, a prior investigation whether and how an algorithm can or will be used in practice is not integrated in the development process. In contrast, in the field of cognitive ergonomics, function allocation methods explicitly take into account human factors in the design of human/computer systems. The function allocation literature, however, is mainly focused on dynamic systems where humans must make decisions in situations with time pressure and important safety risks, e.g., nuclear plants and air traffic control. We analyze the differences between such dynamic systems and planning and scheduling, and we propose a model for function allocation in planning and scheduling taking into account cognitive and human-machine cooperation aspects.

Vehicular Networks

Scipedia content — Mon, 25 Jan 2021 12:23:50 +0100

Critical, Cutting-Edge Insight to Speed Deployment of Vehicular NetworksAs Vehicular Networks technology enters a critical phase in its evolution, academic institutions, industry, and governments worldwide are investing significant resources into large-scale deployment of such networks in order to leverage its benefits to communication, road safety, and improved traffic flow. Despite the current proliferation of conferences to address the technical, policy, and economic challenges associated with this exciting new technology, notably absent is a self-contained book that integrates and covers these topics in sufficient detail.Vehicular Networks: Techniques, Standards and Applications examines the latest advances in the evolution of vehicular networks, presenting invaluable state-of-the-art ideas and solutions for professionals and academics at work on numerous international development and deployment projects. A versatile text, it cross-references all key aspects, including medium access, scheduling, mobility, services, market introduction, and standard specifications. This informative guide:Describes the roles of networks operators, car manufacturers, service providers, and governmental authorities in development of vehicular technologyIllustrates the benefits and real-life applications of vehicular networksAnalyzes possible business models for network deploymentExamines potential services and possible deployment architecturesExplores the technical challenges of deployment, including use of MAC protocols, routing, data dissemination, dynamic IP autoconfiguration, mobility management, security, and driver/passenger privacy Illustrative Figures to Clarify Both Basic and Advanced ConceptsUsing simplified language, this book elucidates the distinct behavior and characteristics that distinguish vehicular networks from other types of mobile networks. It is an invaluable resource for those working with or studying vehicular networks and other wireless or mobile communications systems.

The road to sustainable transport? Rural transport programmes and policies in Ireland

Scipedia content — Mon, 25 Jan 2021 12:19:26 +0100

Book chapter Today many rural dwellers in the Republic of Ireland depend on the private car to access services, employment, education, healthcare and recreation and thus shoulder a disproportionate share of the burden of insufficient public transport. But car dependency does not only affect rural Ireland: those who live in Irish cities, towns and their sub-urbanised hinterlands also experience accessibility problems and reduced 'walkability' resulting from sprawl and a lack of transport alternatives. Recent census figures illustrate the geographical and demographic expansion of urban centres such as Dublin, Cork and Galway which are now extending well into their (semi-) rural hinterlands where public transport is often unavailable. Car dependency thus represents a key challenge for national transport policy in general, and rural public transport provision in particular. Not peer reviewed

Seismic Analysis and Design of Retaining Walls, Buried Structures, Slopes, and Embankments

Scipedia content — Mon, 25 Jan 2021 11:57:03 +0100

This report provides analytical and design methods for the seismic design of retaining walls, buried structures, slopes, and embankments. The report details the development of the design procedures. Recommended load and resistance factor design (LRFD) specifications and design examples illustrating the application of the design methods and specifications are included in an Appendix. The material in this report will be of immediate interest to roadway and bridge designers.

The Speed of Change

Scipedia content — Mon, 25 Jan 2021 11:42:29 +0100

In the early 1900s the motor-vehicle (car, bus, lorry or motorcycle) was introduced in sub-Saharan Africa. Initially the plaything and symbol of colonial domination, the motor-vehicle transformed the economic and social life of the continent. Indeed, the motor-vehicle is arguably the single most important factor for change in Africa in the twentieth century. A factor for change that thus far has been neglected in research and literature. Yet its impact extends across the totality of human existence; from ecological devastation to economic advancement, from cultural transformation to political change, through a myriad of other themes. This edited volume of eleven contributions by historians, anthropologists and social and political scientists explores aspects of the social history and anthropology of the motor-vehicle in Africa.

Multisensor Data Fusion Strategies for Advanced Driver Assistance Systems

Scipedia content — Mon, 25 Jan 2021 11:31:06 +0100

Multisensor data fusion and integration is a rapidly evolving research area that requires interdisciplinary knowledge in control theory, signal processing, artificial intelligence, probability and statistics, etc. Multisensor data fusion refers to the synergistic combination of sensory data from multiple sensors and related information to provide more reliable and accurate information than could be achieved using a single, independent sensor (Luo et al., 2007). Actually Multisensor data fusion is a multilevel, multifaceted process dealing with automatic detection, association, correlation, estimation, and combination of data from single and multiple information sources. The results of data fusion process help users make decisions in complicated scenarios. Integration of multiple sensor data was originally needed for military applications in ocean surveillance, air-to air and surface-to-air defence, or battlefield intelligence. More recently, multisensor data fusion has also included the nonmilitary fields of remote environmental sensing, medical diagnosis, automated monitoring of equipment, robotics, and automotive systems (Macci et al., 2008). The potential advantages of multisensor fusion and integration are redundancy, complementarity, timeliness, and cost of the information. The integration or fusion of redundant information can reduce overall uncertainty and thus serve to increase the accuracy with which the features are perceived by the system. Multiple sensors providing redundant information can also serve to increase reliability in the case of sensor error or failure. Complementary information from multiple sensors allows features in the environment to be perceived that are impossible to perceive using just the information from each individual sensor operating separately. (Luo et al., 2007) Besides, driving as one of our daily activities is a complex task involving a great amount of interaction between driver and vehicle. Drivers regularly share their attention among operating the vehicle, monitoring traffic and nearby obstacles, and performing secondary tasks such as conversing, adjusting comfort settings (e.g. temperature, radio.) The complexity of the task and uncertainty of the driving environment make driving a very dangerous task, as according to a study in the European member states, there are more than 1,200,000 traffic accidents a year with over 40,000 fatalities. This fact points up the growing demand for automotive safety systems, which aim for a significant contribution to the overall road safety (Tatschke et al., 2006). Therefore, recently, there are an increased number of research activities focusing on the Driver Assistance System (DAS) development in order O pe n A cc es s D at ab as e w w w .in te ch w eb .o rg

Optimal Real-Time Estimation Strategies for a Class of Cyber-Physical Systems Using Networked Mobile Sensors and Actuators

Scipedia content — Mon, 25 Jan 2021 11:30:11 +0100

The combination of physical systems and networks has brought to light a new generation of engineered systems: Cyber-Physical Systems (CPS) (CPS, 2008). CPS is defined in (Chen, 2008) in the following way: ``Computational thinking and integration of computation around the physical dynamic systems form Cyber-Physical Systems (CPS) where sensing, decision, actuation, computation, networking and physical processes are mixed". CPS is foreseen to become a highly researched area in the years to come with its own conferences (NSF, 2006; WCPS, 2008) and journals, e.g. (Gill et al, 2008). ``Applications of CPS arguably have the potential to dwarf the 20-th century IT revolution" (Lee, 2007). CPS applications can be found in medical devices and systems, patient monitoring devices, automotive and air traffic control, advanced automotive systems, process control, environmental monitoring, avionics, instrumentation, oil refineries, water usage control, cooperative robotics, manufacturing control, buildings, etc. The first step when considering a CPS is to determine the dynamics of its ``physical" part, i.e. the environment in which the sensors and actuators are going to operate. First by defining a matching mathematical model, and then by retrieving the values of the parameters of this model. In this paper, the parameter estimation process constitutes a CPS in itself as we are using a mobile actuator-sensor network for that purpose. The ``modeling-analysis-design (MAD)'' process in dynamic systems control is fundamental in control engineering practice. In both physical and mathematical modelling, the parameter estimation is essential in successful control designs. A precise parameter estimation depends not only on ``relevant'' measurements and observations, but also on ``rich'' excitation of the system. These are all known concepts in system identification for finite dimensional systems (Ljung, 2008). In control engineering practice, it is very common to estimate the parameters of a system given a mathematical model. Using observations or measurements, one can parameterize the model using different techniques. Sometimes, when the system to be modelled is spatially and temporally dynamic (i.e. the states depend on both time and space), common

Financing Urban Transport Through Value Capture

Scipedia content — Mon, 25 Jan 2021 11:04:57 +0100

The Green Paper on Urban Transport highlights the importance of promoting public transport as a means of achieving better sustainable mobility. Unfortunately, budget resources are often constrained. On the other hand, literature points out that transport infrastructure induce economic impacts in the areas where they are placed. This effect is caused by the fact that people realize the positive effects of accessibility and want to live or work close to transport stations. Regarding this fact a question arises. Is it possible to capture the value induced by the construction of a new infrastructure facility as an additional financial source? The aim of this paper is to analyze different direct and indirect mechanisms of value capture to fund transport infrastructure.

Document type: Part of book or chapter of book

Lock-In Effects Of Road Expansion On CO2 Emissions: Results From A Core-Periphery Model Of Beijing

Scipedia content — Mon, 25 Jan 2021 10:51:28 +0100

In the urban planning literature, it is frequently explicitly asserted or strongly implied that ongoing urban sprawl and decentralization can lead to development patterns that are unsustainable in the long run. One manifestation of such an outcome is that if extensive road investments occur, urban sprawl and decentralization are advanced and locked-in, making subsequent investments in public transit less effective in reducing vehicle kilometers traveled by car, gasoline use and carbon dioxide emissions. Using a simple core-periphery model of Beijing, the authors numerically assess this effect. The analysis confirms that improving the transit travel time in Beijingâs core would reduce the cityâs overall carbon dioxide emissions, whereas the opposite would be the case if peripheral road capacity were expanded. This effect is robust to perturbations in the modelâs calibrated parameters. In particular, the effect persists for a wide range of assumptions about how location choice depends on travel time and a wide range of assumptions about other aspects of consumer preferences.

The vietnamese city in transition

Scipedia content — Mon, 25 Jan 2021 10:44:42 +0100

This work is reproduced here with the kind permission of the publisher, ISEAS - Yusof Ishak Institute, http://bookshop.iseas.edu.sg; International audience; There is no point in attempting to formulate a synthesis of the prÃ©sentations contained in the prÃ©sent publication given the diversity of the subjects. Our ambition here is, firstly, to recapitulate on some of the issues dealt with by the PRUD (Urban Research Programme for Development) projects, as well as to review some of the main characteristics of urban mutations in Vietnam during the current transition period as outlined in the work carried out by the research teams. Secondly, we will suggest orientations for future research: based on existing knowledge accumulated through research projects carried out within the scope of the PRUD, we will either further investigate current thÃ¨mes and issues or explore new ones.

Developing a Framework of Common Information Space (CIS): Grounded Theory Analysis of Airport CIS

Scipedia content — Mon, 25 Jan 2021 10:44:24 +0100

The notion of Common Information Space (CIS) has been proposed in the field of Computer Supported Cooperative Work (CSCW) as a conceptual framework for analyzing cooperative work processes. The area is still in its formative years and requires more research to contribute to its development. This paper presents findings from an investigation undertaken for such an endeavor. Three perceptions of CIS are presented, which are, CIS as a sociotechnical arrangement, dynamic arrangement, and dependency management arrangement. These have been derived from review of existing research contributing to CIS notion development and Grounded Theory analysis of collaborative work process in air traffic control setting. The findings presented in this paper provide a comprehensive and consolidated view of the notion development. The paper contributes to the ongoing discussion of CIS notion development by making theoretical as well as methodological contribution.

Pre-trip and En-route Route Choice in a Dynamic Traffic Assignment Model

Scipedia content — Thu, 21 Jan 2021 15:17:35 +0100

A dynamic traffic assignment framework has been described in which travelers' pre-trip and en-route choices are modeled, including the influence of the pre-trip route choice on the later en-route decisions. Travelers' route choice sets are extended during the dynamic traffic flow simulation to include all reasonable routes from all intersections to all destinations. The en-route route flows are the computed by applying a relative multinominal logit model, in which the generalized route costs include a possible utility for following the route that is chosen pre-trip. The latter is represented by the route overlap factor and a weighting parameter which may also be interpreted as a threshold to deviate from the pre-trip route choice. The proposed framework is widely applicable in dynamic traffic assignment applications, since it enables modeling the synthesis of pre-trip (or dictated) and en-route choices due to, for instance, route guidance, evacuation instructions and unexpected traffic or network conditions (e.g., incidents, accidents and road works), as well as providing a solution to possible gridlock, and is capable of dealing with failure of links.

Exploiting the Inter-Domain Hierarchy for the QoS Network Management

Scipedia content — Thu, 21 Jan 2021 14:54:33 +0100

ISBN 978-1-61520-791-1; The Internet is an interconnection of multiple networks called domains. Inter-domain routing is ensured by BGP which preserves each domain's independence and announces routes arbitrarily chosen by domains. BGP messages carry no information concerning quality parameters of announced routes. The authors' goal is to provide domains with information regarding the congestion state of other domains without any changes in BGP. A domain, which is aware of heavily congested domains, can choose a bypass instead of a route exhibiting possible problems with QoS satisfaction. They propose a mechanism which sends alert messages in order to notify domains about the congestion state of other domains. The major difficulty consists in avoiding flooding the Internet with signaling messages. The authors' solution limits the number of alerts by taking advantage of the hierarchical structure of the Internet set by P2C and P2P relationships. Their algorithm is distributed and heuristic because it is a solution to an NP-complete and inapproximable problem. They prove these properties by reducing the Steiner problem in directed acyclic graphs to our problem of alert diffusion. The simulations show that our mechanism significantly diminishes the number of unavailable domains and routes compared to those obtained with BGP routing and with a theoretical centralized mechanism.

Prospects for Russian : Finnish/EU co-operation

Scipedia content — Thu, 21 Jan 2021 14:50:04 +0100

Treball desenvolupat dins el marc del programa 'European Project Semester'.

Culture Implications on Future Work Design—New Technologies and Collaborations for Controllers and Pilots

Scipedia content — Thu, 21 Jan 2021 14:44:16 +0100

As Air Traffic Control, ATC, has evolved gradually during the 20th century technology, law and culture have been developed and introduced into aviation in such a way that the aviation community in Europe now appears like a patchwork consisting of virtually hundreds of different and fragmented parts. Current harmonisation work such as the European Single Sky initiative may be seen as a reaction to this (European Commission, 1999). In the decade to come aeronautics will face large challenges when capacity limits will be reached because of ever increasing traffic. New technology is now gradually being introduced in order to meet these challenges (Eurocontrol, 1998). In future aviation system pilots and air-traffic controllers will have new roles, responsibilities and ways of collaboration. The context for pilots and controllers work is very different, yet they are complementary actors in a common system. The two groups have different professional cultures and will be part of a common change. This paper consolidate recent research from Air Traffic Control, Flight Operations and Maintenance on issues such as organisational culture, safety culture, implementing major organizational change and a new human factors model. It is suggested that the consolidated research may be applied to and facilitate future changes in their joint system due to the many similarities and differences between flight operations (FO) and air traffic control (ATC) that exist. One conclusion is that the overall implication for future work design between controllers and pilots is not only cultural. It is necessary to develop theoretically sound practice that can create new organisational processes which are functionally effective for all stakeholders and which then provide the basis for a new collective understanding of how the system can work (McDonald, 2009) and go from there. Further research should be focused on discussing the relevance for developing a common process model with training modules for crosslearning and develop a common reporting system to feed common risk models and performance measures. "p"QC 20120222"/p" HILAS

Sustainable Mobility in Metropolitan Areas

Scipedia content — Thu, 21 Jan 2021 14:43:37 +0100

Transport is one of the four priorities of the EU Thematic Strategy on Urban Environment. Cities concentrate 80% of European population and transport is a key element for their economic vitality. However it also produces pollution, noise, global warming, congestion, etc. Some cities have faced this problem - particularly aggravated by this relatively new phenomenon known as urban sprawl, perfectly distinguishable in new housing developments perfectly unsustainable-, through integrated strategies which takes account of the interrelations among land use patterns, transport supply and, last but not least, the role of the different modes of transport, in a sort of co-modality that includes walking and cycling. Sustainable Urban Transport Plan for cities or Company Management Plans for big industries look for those objectives.

Document type: Part of book or chapter of book

The Continuous Risk Profile Approach for the Identification of High Collision Concentration Locations on Congested Highways

Scipedia content — Thu, 21 Jan 2021 14:39:16 +0100

This paper documents a new method for monitoring traffic collision data from continuous roadway facilities to detect high collision concentration locations. Many existing methods for detecting collision concentration locations require segmentation of roadways and assume traffic collision data are spatially uncorrelated, resulting in both false positives (i.e., identifying sites for safety improvements that should not have been selected) and false negatives (i.e., not identifying sites that should have been selected). The proposed method does not require segmentation of roadways; spatial correlation in the collision data does not affect the results of analysis. This new method has a lower false positive rate than the conventional sliding moving window approach. This paper shows how the proposed method can proactively identify high collision concentration locations and capture the benefit of safety improvements observed in the project location and in neighboring sites.

Investigating Boundary Issues Arising from Congestion Charging in a Bottleneck Scenario

Scipedia content — Thu, 21 Jan 2021 14:39:05 +0100

Traffic assignment is a set of criteria through which the demand for mobility is distributed over the links of a transport network. Over the last 30 years, Dynamic Traffic Assignment (DTA) models have been developed to support time-dependent analyses in nascent fields that need to take into account the temporal distribution of demand and supply. In this book, leading international experts in the field provide a state-of-the-art overview of fundamental DTA research and practice, identifying weaknesses and major challenges for future research.

A grounded theory approach towards conceptualizing CIS for heterogeneous work communities

Scipedia content — Thu, 21 Jan 2021 14:30:05 +0100

The notion of Common Information Space (CIS) is an area that has been gaining attention in the field of Computer Supported Cooperative Work (CSCW) over the last few years. This paper discusses one aspect of the investigation being undertaken to develop the conceptualization of CIS pertaining to heterogeneous work communities. This is based on empirical study of collaborative decision making involving different work communities in an airport of the air traffic control setting. The theory development is founded on the Grounded Theory approach. We present some of the findings of the ongoing analysis. In particular we discuss how the Grounded Theory methodological process has been adapted to this investigation by presenting illustrations of emergent theory development at the theoretical coding phase of the process.

Document type: Part of book or chapter of book

The World Bank in Nigeria, 1998-2007 : Nigeria Country Assistance Evaluation

Scipedia content — Thu, 21 Jan 2021 14:27:31 +0100

This country assistance evaluation assesses the outcomes of the World Banks program in Nigeria during the period 1998â2007. The Country Assistance Evaluation focuses on the objectives of that assistance and the extent to which outcomes were consistent with those objectives. It looks at the Banks contribution to the achievement of those outcomes and at the lessons for the Banks future activities in Nigeria and in other countries. The evaluation includes a review of relevant documents, complemented by interviews with Bank staff and other key donors, as well as with representatives of the Nigerian government, the private sector, and civil society. Overall, the outcomes of the Bank program in Nigeria are rated as moderately unsatisfactory. This reflects an improvement relative to IEGâs 2000â04 assessment, which rated the outcome of Bank assistance as unsatisfactory. The current assessment recognizes the countryâs signal achievements in maintaining macroeconomic stability and laying the basis for more effective and cost-efficient performance of the central government. There are major risks associated with this, however. The earnings from Nigeriaâs oil and gas resources require strong management that puts the national interest ahead of that of individuals and state governments. In the fragmented context of Nigerian politics, that is a tough proposition to maintain. If the government shows the necessary leadership and successfully leverages the resources it has to provide incentives to state governments to do a better job of delivering social services, there is the potential for real progress in reducing poverty and achieving the MDGs.

The vietnamese city in transition

Scipedia content — Thu, 21 Jan 2021 14:21:32 +0100

The present work was undertaken as part of two cooperation programmes between French and Vietnamese local governments: one involving the Ile-de-France Region and Hanoi Peopleâs Committee, the other the Rhone- Alpes Region and Ho Chi Minh City Peopleâs Committee. It was published with financial support from the Cooperation and Cultural Action Office (SCAC) of the French Embassy in Vietnam. Gathered here are the main results obtained by the Franco-Vietnamese research teams involved in the Urban Research Programme for Development (PRUD) funded by the French Ministry of Foreign Affairs. As the outcome of joint concertation, it illustrates the coherence between the various French cooperation programmes in Vietnam.; International audience; The research presented here attempts to define the issues at stake in urban development in Vietnam under the economic and demographic push induced by the transition from a centralized planned economy to a globalized market economy, and by strong urban population growth. Processes at work such as international integration and fast-growing metropolisation, speeded up economic development, devolution/decentralization of urban management authorities, modernization of housing patterns, poorly controlled peri-urban urbanization, mutations in the management of urban services, etc., all require strengthening of skills for urban project management and local government.

A Model for the Traveling Salesman Problem Including the EC Regulations on Driving Hours

Scipedia content — Thu, 21 Jan 2021 13:47:41 +0100

Since April 2007 the new EC Regulation No 561/2006 concerning driving hours in road transport is effective. This regulation restricts the length of time periods for driving and requires minimum breaks and rest periods for drivers [2]. An analysis of the EC Regulation with respect to vehicle routing can be found in [3]. In this paper the restrictions on driving times and the need for breaks are formalized and integrated in an optimization model of the TSPTW. The solution space of the extended traveling salesman problem with time windows and EUconstraints (TSPTW-EU) contains all Hamiltonian circuits which full the given time windows and restrictions of the Regulation relevant for a time period up to one week. The presented approach for extending the TSPTW to the TSPTW-EU is also applicable for the extension of the VRPTW and PDPTW, thus offering a possibility to include the EC Regulations in vehicle routing and scheduling.

Air Traffic Control Tracking Systems Performance Impacts with New Surveillance Technology Sensors

Scipedia content — Thu, 21 Jan 2021 13:30:50 +0100

Nowadays, the radar is no longer the only technology able to ensure the surveillance of air traffic. The extensive deployment of satellite systems and air-to-ground data links lead to the emergence of other means and techniques on which a great deal of research and experiments have been carried out over the past ten years. In such an environment, the sensor data processing, which is a key element of an Air Traffic Control center, has been continuously upgraded so as to follow the sensor technology evolution and, at the same time, ensure a more efficient tracking continuity, integrity and accuracy. In this book chapter we propose to measure the impacts of the use of these new technology sensors in the tracking systems currently used for Air Traffic Control applications. The first part of the chapter describes the background of new-technology sensors that are currently used by sensor data processing systems. In addition, a brief definition of internal core tracking algorithms used in sensor data processing components, is given as well as a comparison between their respective advantages and drawbacks. The second part of the chapter focuses on the Multi Sensor Tracking System performance requirements. Investigation regarding the use of Automatic Dependent Surveillance â Broadcast reports and/or with a multi radars configuration, are conducted. The third part deals with the impacts of the âvirtual radarâ or âradar-likeâ approaches that can be used with ADS-B sensors, on the multi sensor tracking system performance. The fourth and last part of the chapter discusses the impacts of sensor data processing performance on sub-sequent safety nets functions that are: â¢ Short term conflict alerts (STCA), â¢ Minimum Safe Altitude Warnings (MSAW), and â¢ Area Proximity Warnings (APW).

Multi Sensor Data Fusion Architectures for Air Traffic Control Applications

Scipedia content — Thu, 21 Jan 2021 13:14:36 +0100

Nowadays, the radar is no longer the sole technology which is able to ensure the surveillance of air traffic. The extensive deployment of satellite systems and air-to-ground data links leads to the emergence of complementary means and techniques on which a great deal of research and experiments have been carried out over the past ten years. In such an environment, the sensor data processing, which is a key element in any Air Traffic Control (ATC) centre, has been continuously upgraded so as to follow the sensor technology evolution and in the meantime improves the quality in term of continuity, integrity and accuracy criteria. This book chapter proposes a comprehensive description of the state of art and the roadmap for the future of the multi sensor data fusion architectures and techniques in use in ATC centres. The first part of the chapter describes the background of ATC centres, while the second part of the chapter points out various data fusion techniques. Multi radar data processing architecture is analysed and a brief definition of internal core tracking algorithms is given as well as a comparative benchmark based on their respective advantages and drawbacks. The third part of the chapter focuses on the most recent evolution that leads from a Multi Radar Tracking System to a Multi Sensor Tracking System. The last part of the chapter deals with the sensor data processing that will be put in operation in the next ten years. The main challenge will be to provide the same level of services in both surface and air surveillance areas in order to offer: â¢ highly accurate air and surface situation awareness to air traffic controllers, â¢ situational awareness via Traffic Information System â Broadcast (TIS-B) services to pilots and vehicle drivers, and â¢ new air and surface safety, capacity and efficiency applications to airports and airlines.

Computational Fluid Dynamics Methods for Gas Pipeline System Control

Scipedia content — Thu, 21 Jan 2021 13:07:18 +0100

At the present level of development of long, branched gas transmission networks (GTN), solving the problems of improving safety, efficiency and environmental soundness of operation of industrial pipeline systems calls for the application of methods of numerical simulation. The development of automated devices for technical inspection and process control, and availability of high-performance computer hardware have created a solid technical basis to introduce numerical simulation methods into the industrial practice of GTN analysis and operation. One of the promising approaches for numerical analysis of GTN operating is the development and application of high-accuracy computational fluid dynamics (CFD) simulators of modes of gas mixture transmission through long, branched pipeline systems (CFD-simulator) (Seleznev, 2007). Actually, a CFD-simulator is a special-purpose software simulating, in âonlineâ and âreal timeâ modes with a high similarity and in sufficient detail, the physical processes of gas mixture transmission through a particular GTN. The development of a CFD-simulator focuses much attention to correctness of simulation of gas flows in the pipelines and to the impact produced by operation of relevant GTN gas pumping equipment (including gas compressor unit (GCU), valves, gas pressure reducers, etc.) and the environment upon the physical processes under study. From the standpoint of mathematical physics, a CFD-simulator performs numerical simulation of steady and transient, non-isothermal processes of a gas mixture flow in long, branched, multi-line, multi-section gas pipeline network. Such simulation is aimed at obtaining high-accuracy estimates of the actual distribution (over time and space) of fluid dynamics parameters for the full range of modes of gas mixture transmission through the specific GTN in normal and emergency conditions of its operation, as well as of the actual (temporal) distribution of main parameters of GTN equipment operation, which can be

Investigation of pipelines integrity associated with pump modules vibration for pumping station 9 of alyeska pipeline service company

Scipedia content — Mon, 26 Oct 2020 15:44:20 +0100

Since the operation of PS09 SR module in 2007, it has been observed that there is vibration in various parts of the structures, on various segments of piping, and on appurtenance items. At DOT Pipeline and Hazardous Materials Safety Administration (PHMSA) request, ORNL Subject Matter Experts support PHMSA in its review and analysis of the observed vibration phenomenon. The review and analysis consider possible effects of pipeline design features, vibration characteristics, machinery configuration, and operating practices on the structural capacity and leak tight integrity of the pipeline. Emphasis is placed on protection of welded joints and machinery against failure from cyclic loading. A series of vibration measurements were carried out by the author during the site visit to PS09, the power of the operating pump during the data collection is at about 2970KW, which is less than that of APSC's vibration data collected at 3900KW. Thus, a first order proportional factor of 4900/2970 was used to project the measured velocity data to that of APSC's measurement of the velocity data. It is also noted here that the average or the peak-hold value of the measured velocity data was used in the author's reported data, and only the maximum peak-hold data was used in APSC's reported data. Therefore, in some cases APSC's data is higher than the author's projective estimates that using the average data. In general the projected velocity data are consistent with APSC's measurements; the examples of comparison at various locations are illustrated in the Table 1. This exercise validates and confirms the report vibration data stated in APSC's summary report. After the reinforcement project for PS09 Station, a significant reduction of vibration intensity was observed for the associated pipelines at the SR Modules. EDI Co. provided a detailed vibration intensity investigation for the newly reinforced Pump Module structures and the associated pipelines. A follow-up review of EDI's report was carried out by the author. The comments and questions regarding the EDI report are categorized into four subjects, namely (1) piping vibration severity, (2) pulsation and its impact on the PS09 structure and piping, (3) strain-gage stress history profiles, and (4) the cavitation potential investigation, where the questions are stated at the end of the comments for further follow-on investigations.

Document type: Report

Probabilistic risk based decision support for oil and gas exploration and production facilities in sensitive ecosystems

Scipedia content — Mon, 26 Oct 2020 15:41:57 +0100

This report describes work performed during the initial period of the project ÂProbabilistic Risk Based Decision Support for Oil and Gas Exploration and Production Facilities in Sensitive Ecosystems.Â The specific region that is within the scope of this study is the Fayetteville Shale Play. This is an unconventional, tight formation, natural gas play that currently has approximately 1.5 million acres under lease, primarily to Southwestern Energy Incorporated and Chesapeake Energy Incorporated. The currently active play encompasses a region from approximately Fort Smith, AR east to Little Rock, AR approximately 50 miles wide (from North to South). The initial estimates for this field put it almost on par with the Barnett Shale play in Texas. It is anticipated that thousands of wells will be drilled during the next several years; this will entail installation of massive support infrastructure of roads and pipelines, as well as drilling fluid disposal pits and infrastructure to handle millions of gallons of fracturing fluids. This project focuses on gas production in Arkansas as the test bed for application of proactive risk management decision support system for natural gas exploration and production. The activities covered in this report include meetings with representative stakeholders, development of initial content and design for an educational web site, and development and preliminary testing of an interactive mapping utility designed to provide users with information that will allow avoidance of sensitive areas during the development of the Fayetteville Shale Play. These tools have been presented to both regulatory and industrial stakeholder groups, and their feedback has been incorporated into the project.

Document type: Report

A climate for collaboration. Analysis of US and EU lessons and opportunities in energy and climate policy

Scipedia content — Mon, 26 Oct 2020 15:35:36 +0100

A deepening of cooperation between the United States and the European Union requires mutual trust, and understanding of current policies, challenges and successes. Through providing such understanding among policymakers, industry and other stakeholders in both economies, opportunities for transatlantic cooperation on climate change and energy policy emerge. This paper sets out by discussing the environmental, legislative, and economic contexts of the EU and US as related to climate. This context is essential to understanding how cap-and-trade, renewable energy and sustainable transportation policies have taken shape in the EU and the US, as described in Chapter 3.1. For each of these policies, a barrier analysis and discussion is provided. Chapter 4 builds off this improved understanding to listobservations and possible lessons learned. The paper concludes with recommendations on topics where EU and US interests align, and where further cooperation could prove beneficial.

Document type: Report

An Assessment of the Commercial Availability of Carbon Dioxide Capture and Storage Technologies as of June 2009

Scipedia content — Mon, 26 Oct 2020 15:33:28 +0100

Currently, there is considerable confusion within parts of the carbon dioxide capture and storage (CCS) technical and regulatory communities regarding the maturity and commercial readiness of the technologies needed to capture, transport, inject, monitor and verify the efficacy of carbon dioxide (CO2) storage in deep, geologic formations. The purpose of this technical report is to address this confusion by discussing the state of CCS technological readiness in terms of existing commercial deployments of CO2 capture systems, CO2 transportation pipelines, CO2 injection systems and measurement, monitoring and verification (MMV) systems for CO2 injected into deep geologic structures. To date, CO2 has been captured from both natural gas and coal fired commercial power generating facilities, gasification facilities and other industrial processes. Transportation via pipelines and injection of CO2 into the deep subsurface are well established commercial practices with more than 35 years of industrial experience. There are also a wide variety of MMV technologies that have been employed to understand the fate of CO2 injected into the deep subsurface. The four existing end-to-end commercial CCS projects Â Sleipner, Snohvit, In Salah and Weyburn Â are using a broad range of these technologies, and prove that, at a high level, geologic CO2 storage technologies are mature and capable of deploying at commercial scales. Whether wide scale deployment of CCS is currently or will soon be a cost-effective means of reducing greenhouse gas emissions is largely a function of climate policies which have yet to be enacted and the publicÂs willingness to incur costs to avoid dangerous anthropogenic interference with the EarthÂs climate. There are significant benefits to be had by continuing to improve through research, development, and demonstration suite of existing CCS technologies. Nonetheless, it is clear that most of the core technologies required to address capture, transport, injection, monitoring, management and verification for most large CO2 source types and in most CO2 storage formation types, exist.

Document type: Report

The use of taborr as a heavy oil upgrader

Scipedia content — Mon, 26 Oct 2020 12:29:33 +0100

Preliminary testing has shown that Western Research Institute's (WRI) Tank Bottom Recovery and Remediation (TaBoRR{reg_sign}) technology shows promise for heavy oil upgrading. Approximately 70 to 75 wt% of a Canadian Cold Lake bitumen feed was converted to a partially upgraded overhead product that could be transported directly by pipeline or blended with the parent bitumen to produce transportable crude. TaBoRR{reg_sign} was originally developed to remediate tank bottom wastes by producing a distillate product and solid waste. TaBoRR{reg_sign}'s processing steps include breaking a water-oil emulsion, recovering a light hydrocarbon fraction by distillation in a stripper unit, and pyrolyzing the residua reducing it to additional overhead and a benign coke for disposal. Cold Lake bitumen was tested in WRI's bench-scale equipment to evaluate the potential use of TaBoRR{reg_sign} technology for heavy oil upgrading to produce a stable, partially (or fully) upgraded product that will allow diluent-reduced or diluent-free transportation of bitumen or ultra-heavy crudes to market. Runs were conducted at temperatures of low, intermediate and high severity in the stripper to produce stripper overhead and bottoms. The bottoms from each of these runs were processed further in a 6-inch screw pyrolyzer to produce pyrolyzer overhead for blending with the corresponding stripper overheads.moreÂ Â» Proceeding in this fashion yielded three partially upgraded crudes. The products from TaBoRR{reg_sign} processing, the parent bitumen, and bitumen blends were subjected to stability and compatibility testing at the National Centre for Upgrading Technology (NCUT). Chemical analyses of the overhead product blends have met pipeline specifications for viscosity and density; however the bromine number does not, which might indicate the need for mild hydrotreating. Storage stability tests showed the blends to be stable. The blends were also soluble and compatible with most other Alberta crudes.Â«Â le

Document type: Report

A qualitative investigation of deposition velocities of a non newtonian slurry in complex pipeline geometries

Scipedia content — Mon, 26 Oct 2020 11:25:52 +0100

The External Flowsheet Review Team (EFRT) has identified the issues relating to the Waste Treatment and Immobilization Plant (WTP) pipe plugging. Per the reviewÂs executive summary, ÂPiping that transports slurries will plug unless it is properly designed to minimize this risk. This design approach has not been followed consistently, which will lead to frequent shutdowns due to line plugging.Â To evaluate the potential for plugging, testing was performed to determine critical velocities for the complex WTP piping layout. Critical velocity is defined as the point at which a moving bed of particles begins to form on the pipe bottom during slurry-transport operations. Pressure drops across the fittings of the test pipeline were measured with differential pressure transducers, from which the critical velocities were determined. A WTP prototype flush system was installed and tested upon the completion of the pressure-drop measurements. We also provide the data for the overflow relief system represented by a WTP complex piping geometry with a non-Newtonian slurry. A waste simulant composed of alumina (nominally 50 ?m in diameter) suspended in a kaolin clay slurry was used for this testing. The target composition of the simulant was 10 vol% alumina in a suspending medium with a yieldmoreÂ Â» stress of 3 Pa. No publications or reports are available to confirm the critical velocities for the complex geometry evaluated in this testing; therefore, for this assessment, the results were compared to those reported by Poloski et al. (2008) for which testing was performed for a straight horizontal pipe. The results of the flush test are compared to the WTP design guide 24590-WTP-GPG-M-0058, Rev. 0 (Hall 2006) in an effort to confirm flushing-velocity requirements.Â«Â le

Document type: Report

Distributed data flow for in situ visualization and analysis at petascale

Scipedia content — Mon, 26 Oct 2020 09:52:10 +0100

We conducted a feasibility study to research modifications to data-flow architectures to enable data-flow to be distributed across multiple machines automatically. Distributed data-flow is a crucial technology to ensure that tools like the VisIt visualization application can provide in-situ data analysis and post-processing for simulations on peta-scale machines. We modified a version of VisIt to study load-balancing trade-offs between light-weight kernel compute environments and dedicated post-processing cluster nodes. Our research focused on memory overheads for contouring operations, which involves variable amounts of generated geometry on each node and computation of normal vectors for all generated vertices. Each compute node independently decided whether to send data to dedicated post-processing nodes at each stage of pipeline execution, depending on available memory. We instrumented the code to allow user settable available memory amounts to test extremely low-overhead compute environments. We performed initial testing of this prototype distributed streaming framework, but did not have time to perform scaling studies at and beyond 1000 compute-nodes.

Document type: Report

The physics of galaxy evolution with EAGLE.

Scipedia content — Wed, 14 Oct 2020 16:37:40 +0200

One of the prominent science goal of the ELTs will be to study the physics and mass assembly of galaxies at very high redshifts. Here, we present the galaxy evolution science case for EAGLE, which is a NIR multi-integral field spectrograph for the E-ELT currently under phase A study. We summarize results of simulations conducted to derive high-level requirements. In particular, we show how we have derived the specifications for the ensquared energy that the AO system needs to provide to reach the scientific goals of the instrument. Finally, we present future strategies to conduct galaxy surveys with EAGLE.

Document type: Part of book or chapter of book

Cordon pricing consistent with the physics of overcrowding

Scipedia content — Wed, 14 Oct 2020 16:33:03 +0200

This paper describes the modeling of recurring congestion in a network. It is shown that the standard economic models of marginal cost cannot describe precisely traffic congestion in networks during time-dependent conditions. Following a macroscopic traffic approach, we describe the equilibrium solution for a congested network in the no-toll case. A dynamic model of cordon-based congestion pricing (such as for the morning commute) for networks is developed consistent with the physics of traffic.Ê The paper combines VickreyÕs theory with a macroscopic traffic model, which is readily observable with existing monitoring technologies. The paper also examines some policy implications of the cordon-based pricing to treat equity and reliability issues, i.e. in what mobility level a city should choose to operate. An application of the model in a downtown area shows that these schemes can improve mobility and relieve congestion in cities.

Document type: Part of book or chapter of book

Enhancing application identification by means of sequential testing

Scipedia content — Wed, 14 Oct 2020 16:20:52 +0200

One of the most important challenges for network administrators is the identification of applications behind the Internet traffic. This identification serves for many purposes as in network security, traffic engineering and monitoring. The classical methods based on standard port numbers or deep packet inspection are unfortunately becoming less and less efficient because of encryption and the utilization of non standard ports. In this paper we come up with an online iterative probabilistic method that identifies applications quickly and accurately by only using the size of packets. Our method associates a configurable confidence level to the port number carried in the transport header and is able to consider a variable number of packets at the beginning of a flow. By verification on real traces we observe that even in the case of no confidence in the port number, a very high accuracy can be obtained for well known applications after few packets were examined.

Document type: Part of book or chapter of book

Looking for the 3d picture the spatio temporal realm of student controllers

Scipedia content — Wed, 14 Oct 2020 16:19:49 +0200

Employing three-dimensional displays in Air Traffic Control (ATC) has been the object of study and debates for numerous years. Although empirical studies have often led to mixed results, some preliminary evidence suggests that training could be a suitable domain of application for 3D interfaces. Little evidence, however, is available to fully support this claim. We attempted to fill this gap with a project that aims at studying and evaluating 3D displays for ATC training purposes. This paper describes the first steps of this project, by reporting and discussing the results of a study aiming at understanding whether ATC trainees form a three-dimensional image of air traffic and at comprehending what the nature of this `3D picture' is.

Document type: Part of book or chapter of book

Detection of linear structures in remote sensed images

Scipedia content — Wed, 14 Oct 2020 16:07:21 +0200

Over the past decades, considerable progress had been made in developing automatic image interpretation tools for remote sensing. There is, however, still a gap between the requirements of applications and system capabilities. Interpretation of noisy aerial images, especially in low resolution, is still difficult. We present a system aimed at detecting faint linear structures, such as pipelines and access roads, in aerial images. We introduce an orientation-weighted Hough transform for the detection of line segments and a Markov Random Field model for combining line segments into linear structures. Empirical results show that the proposed method yields good detection performance.

Document type: Part of book or chapter of book

Minimum delay load balancing through non parametric regression

Scipedia content — Wed, 14 Oct 2020 16:02:35 +0200

Network convergence and new applications running on end-hosts result in increasingly variable and unpredictable traffic patterns. By providing origin-destination pairs with several possible paths, load-balancing has proved itself an excellent tool to face this uncertainty. Formally, load-balancing is defined in terms of a convex link cost function of its load, where the objective is to minimize the total cost. Typically, the link queueing delay is used as this cost since it measures its congestion. Over-simplistic models are used to calculate it, which have been observed to result in suboptimal resource usage and total delay. In this paper we investigate the possibility of learning the delay function from measurements, thus converging to the actual minimum. A novel regression method is used to make the estimation, restricting the assumptions to the minimum (e.g. delay should increase with load). The framework is relatively simple to implement, and we discuss some possible variants.

Document type: Part of book or chapter of book

Evolutionary and preferential attachment models of demand growth

Scipedia content — Wed, 14 Oct 2020 16:01:25 +0200

It is widely acknowledged that, to create models for transportation planning that recognize the essential dynamic character of passenger network flows, one must consider two time scales: the so-called within-day time scale and the day-to-day time scale. Substantial progress has been made in modelling within-day dynamic flows for fixed trip matrices; one of the most widely acknowledged models for this purpose is the dynamic user equilibrium model proposed by Friesz et al. (1993) and studied by Xu et al. (1999), Wu et al. (1998), Friesz et al. (2001), Bliemer and Bovy (2003), and Friesz and Mookherjee (2006). In this chapter we propose two day-to-day models of demand growth compatible with a differential variational inequality formulation of the Friesz et al. (1993) model. The first of these employs dynamics inspired by evolutionary game theory, while the second uses the perspective of preferential attachment familiar from the network science and social network literature to create a model of demand growth. Additionally, numerical experiments to compare and contrast the two proposed theories of demand growth are described, along with hypotheses that one might address via such experiments.

Document type: Part of book or chapter of book

Computational fluid dynamics methods for gas pipeline system control

Scipedia content — Wed, 14 Oct 2020 15:59:09 +0200

At the present level of development of long, branched gas transmission networks (GTN), solving the problems of improving safety, efficiency and environmental soundness of operation of industrial pipeline systems calls for the application of methods of numerical simulation. The development of automated devices for technical inspection and process control, and availability of high-performance computer hardware have created a solid technical basis to introduce numerical simulation methods into the industrial practice of GTN analysis and operation. One of the promising approaches for numerical analysis of GTN operating is the development and application of high-accuracy computational fluid dynamics (CFD) simulators of modes of gas mixture transmission through long, branched pipeline systems (CFD-simulator) (Seleznev, 2007). Actually, a CFD-simulator is a special-purpose software simulating, in online and real time modes with a high similarity and in sufficient detail, the physical processes of gas mixture transmission through a particular GTN. The development of a CFD-simulator focuses much attention to correctness of simulation of gas flows in the pipelines and to the impact produced by operation of relevant GTN gas pumping equipment (including gas compressor unit (GCU), valves, gas pressure reducers, etc.) and the environment upon the physical processes under study. From the standpoint of mathematical physics, a CFD-simulator performs numerical simulation of steady and transient, non-isothermal processes of a gas mixture flow in long, branched, multi-line, multi-section gas pipeline network. Such simulation is aimed at obtaining high-accuracy estimates of the actual distribution (over time and space) of fluid dynamics parameters for the full range of modes of gas mixture transmission through the specific GTN in normal and emergency conditions of its operation, as well as of the actual (temporal) distribution of main parameters of GTN equipment operation, which can be

Document type: Part of book or chapter of book

The Taxation Of Motor Fuel : International Comparison

Scipedia content — Wed, 14 Oct 2020 15:54:34 +0200

This paper assesses whether the level of taxation of motor fuel is broadly appropriate in a group of countries (OECD, BRICs and South Africa) accounting for more than 80 percent of world greenhouse gas emissions. The analysis deals with emissions from oil combustion in transport, which account for about 40 percent of carbon dioxide emissions. In the benchmark specification, six countries (responsible, in turn, for more than 40 percent of worldwide motor-fuel greenhouse gas world emissions) would be undertaxing motor fuel. The authors evaluate the sensitivity of the results to the values of the elasticities and externalities that used in the analysis. They find that varying the values of these parameters (within the level of uncertainty reasonably associated with them) significantly affects the results. This implies that, while informative, the results must be taken as indicative. Further analysis for a particular country must rely on a well-informed choice for the values of the country-specific parameters.

Document type: Book

Impacts Of Policy Instruments To Reduce Congestion And Emissions From Urban Transportation : The Case Of Sao Paulo, Brazil

Scipedia content — Wed, 14 Oct 2020 15:48:20 +0200

This study examines impacts on net social benefits or economic welfare of alternative policy instruments for reducing traffic congestion and atmospheric emissions in São Paulo, Brazil. The study shows that expanding road networks, subsidizing public transit, and improving automobile fuel economy may not be as effective as suggested by economic theories because these policies could cause significant rebound effects. Although pricing instruments such as congestion tolls and fuel taxes would certainly reduce congestion and emissions, the optimal level of these instruments would steeply increase the monetary cost of travel per trip and are therefore politically difficult to implement. However, a noticeable finding is that even smaller tolls, which are more likely to be politically acceptable, have substantial benefits in terms of reducing congestion and emissions. Among the various policy instruments examined in the study, the most socially preferable policy option for São Paulo would be to introduce a mix of congestion toll and fuel taxes on automobiles and use the revenues to improve public transit systems.

Document type: Book

The impact of automation assisted aircraft separation on situation awareness

Scipedia content — Wed, 14 Oct 2020 15:46:22 +0200

This study compared situation awareness across three flight deck decision aiding modes. Pilots resolved air traffic conflicts using a click and drag software tool. In the automated aiding condition, pilots executed all resolutions generated by the automation. In the interactive condition, automation suggested a maneuver, but pilots had the choice of accepting or modifying the provided resolution. In the manual condition pilots generated resolutions independently. A technique that combines both Situation Global Assessment Technique and Situation Present Awareness Method was used to assess situation awareness. Results showed that situation awareness was better in the Manual and Interactive conditions when compared to the Automated condition. The finding suggests that pilots are able to maintain greater situation awareness when they are actively engaged in the conflict resolution process.

Document type: Part of book or chapter of book

Lessons from an overview of national transport surveys, from working group 3 of COST 355: Changing behavior toward a more sustainable transport system

Scipedia content — Wed, 14 Oct 2020 15:40:32 +0200

Abstract\r This chapter summarizes some of the results from the Working Group National Travel Surveys in COST Action 355. All 50 presentations could not be reviewed here; thus, we focus on three crucial topics: \r \r the periodicity of data collection, but also its longitudinal aspects (advantages of continuous surveying, repeated cross-sections vs. panel surveys, etc.),\r \r \r new technologies for improving the efficiency and accuracy of mobility surveys (computer-assisted telephone, Web-based, interviews, GPS, GSM, RDS, etc.),\r \r \r innovative approaches, exemplified by qualitative surveys combined with conventional quantitative ones, and by biographical approaches.

Document type: Part of book or chapter of book

Hierarchical modelling and model adaptivity for gas flow on networks

Scipedia content — Wed, 14 Oct 2020 15:38:42 +0200

We are interested in the simulation and optimization of gas transport in networks. Different regions of the network may be modelled by different equations. There are three models based on the Euler equations that describe the gas flow in pipelines qualitatively different: a nonlinear model, a semilinear model and a stationary also called algebraic model. For the whole network, adequate initial and boundary values as well as coupling conditions at the junctions are needed. Using adjoint techniques, one can specify model error estimators for the simplified models. A strategy to adaptively apply the different models in different regions of the network while maintaining the accuracy of the solution is presented.

Document type: Part of book or chapter of book

Natural gas and geopolitics natural gas pipelines in the southern cone

Scipedia content — Wed, 14 Oct 2020 15:37:16 +0200

Document type: Part of book or chapter of book

An analysis of various policy instruments to reduce congestion, fuel consumption and CO2 emissions in Beijing

Scipedia content — Wed, 14 Oct 2020 15:20:37 +0200

Document type: Book

Developing a framework of common information space cis grounded theory analysis of airport cis

Scipedia content — Wed, 14 Oct 2020 15:19:31 +0200

Document type: Part of book or chapter of book