Scipedia: Documents published in 2013

Load balance vs energy efficiency in traffic engineering: A game Theoretical Perspective

Scipedia content — Thu, 28 Jan 2021 20:37:05 +0100

In this paper, we study the tradeoff between two important traffic engineering objectives: load balance and energy efficiency. Although traditional commonly used multi-objective optimization methods can yield a Pareto efficient solution, they need to construct an aggregate objective function (AOF) or model one of the two objectives as a constraint in the optimization problem formulation. As a result, it is difficult to achieve a fair tradeoff between these two objectives. Accordingly, we induce a Nash bargaining framework which treats the two objectives as two virtual players in a game theoretic model, who negotiate how traffic should be routed in order to optimize both objectives. During the negotiation, each of them announces its performance threat value to reduce its cost, so the model is regarded as a threat value game. Our analysis shows that no agreement can be achieved if each player sets its threat value selfishly. To avoid such a negotiation break-down, we modify the threat value game to have a repeated process and design a mechanism to not only guarantee an agreement, but also generate a fair solution. In addition, the insights from this work are also useful for achieving a fair tradeoff in other multi-objective optimization problems.

Overview: Techniques for the Analysis of Spectral and Orbital Congestion in Space Systems

Scipedia content — Thu, 28 Jan 2021 20:36:49 +0100

Future growth in commercial and military space systems is constrained by technical problems associated with the frequency spectrum, by orbital congestion, and by costs stemming from proliferated terminals. The authors outline an Air Force sponsored research project to design and develop a capability for predicting and analyzing the spectrum/orbital geometry requirements of current/projected U.S. and international space-related systems. The two essential components of the project are a comprehensive space environment data base and a computer analysis program. In combination, they will provide a resource for evaluating engineering and architectural designs, identifying and analyzing the impact of intentional and unintentional electromagnetic interference, and predicting probable saturation conditions in spectrum usage and satellite/orbital positions. The projected capabilities could provide an essential national resource for management decisionmaking and architectural planning on space-related programs. The U.S. Air Force Space Division is establishing a continuing project to utilize these capabilities.

Preparing for cyber-attacks on air traffic management infrastructures: cyber-safety scenario generation

Scipedia content — Thu, 28 Jan 2021 20:36:31 +0100

Malware poses a growing threat to a host of safety-critical systems that depend on common software components, including the Linux operating system and the Internet Protocol (IP). Threats include `mass market' malware that is not deliberately aimed at safety-related systems. They also include more sophisticated techniques exploited by W32.Stuxnet, W32.Duqu, W32.Flame etc. Previous work in this area has focused on the consequences of a cyber-attack under `optimal conditions'. Very little work has been done to identify more complex scenarios when malware exacerbates routine system failures that occur in all safety-critical applications. We show how Vulnerability and Violation (V2) diagrams can identify interactions between malware and degraded modes of operation. The intention is not to accurately predict future modes of attack. In contrast, the aim is to create training scenarios that test the expertise and judgement of systems engineers, operators and managers. The initial results from our work have revealed the underlying vulnerabilities that exist across safety-critical transportation infrastructures. (6 pages)

Real-Time Air Traffic Flow Estimation for Improved Situational Awareness in the Terminal Area

Scipedia content — Thu, 28 Jan 2021 20:34:36 +0100

The problem of estimating the characteristics of the air traffic flow in the Terminal Area is considered. The estimated parameters can be used by the Traffic Flow Coordinators and Terminal Area Controllers to improve their response to varying air traffic flow. The approach is based on a queuing abstraction of the arrival and departure traffic routes in the Terminal Area. The routes are discretized as spatial servers for enforcing FAA-mandated separation requirements. Particle filtering methodology is employed for estimating the timevarying queuing parameters using radar track data. By considering the waypoint crossing times and airspeed as measurements, it is shown that it is feasible to estimate the time delay and its rate at various points along the arrival-departure routes. The proposed approach is illustrated using arrival radar track data in the San Francisco Metroplex. A graphic display of estimated parameters to serve as decision support tool for use by the Terminal Area traffic controllers is also illustrated.

Beyond myopic inference in big data pipelines

Scipedia content — Thu, 28 Jan 2021 20:13:22 +0100

Big Data Pipelines decompose complex analyses of large data sets into a series of simpler tasks, with independently tuned components for each task. This modular setup allows re-use of components across several different pipelines. However, the interaction of independently tuned pipeline components yields poor end-to-end performance as errors introduced by one component cascade through the whole pipeline, affecting overall accuracy. We propose a novel model for reasoning across components of Big Data Pipelines in a probabilistically well-founded manner. Our key idea is to view the interaction of components as dependencies on an underlying graphical model. Different message passing schemes on this graphical model provide various inference algorithms to trade-off end-to-end performance and computational cost. We instantiate our framework with an efficient beam search algorithm, and demonstrate its efficiency on two Big Data Pipelines: parsing and relation extraction.

Reliable Sensing of Leaks in Pipelines

Scipedia content — Thu, 28 Jan 2021 20:11:59 +0100

Leakage is the major factor for unaccounted losses in every pipe network around the world (oil, gas or water). In most cases the deleterious effects associated with the occurrence of leaks may present serious economical and health problems. Therefore, leaks must be quickly detected, located and repaired. Unfortunately, most state of the art leak detection systems have limited applicability, are neither reliable nor robust, while others depend on user experience."/jats:p" "jats:p"In this work we present a new in-pipe leak detection system, PipeGuard. PipeGuard performs autonomous leak detection in pipes and, thus, eliminates the need for user experience. This paper focuses on the detection module and its main characteristics. Detection in based on the presence of a pressure gradient in the neighborhood of the leak. Moreover, the proposed detector can sense leaks at any angle around the circumference of the pipe with only two sensors. We have validated the concepts by building a prototype and evaluated its performance under real conditions in an experimental laboratory setup.

Markov Random Field Model for Single Image Defogging

Scipedia content — Thu, 28 Jan 2021 20:08:35 +0100

Fog reduces contrast and thus the visibility of vehicles and obstacles for drivers. Each year, this causes traffic accidents. Fog is caused by a high concentration of very fine water droplets in the air. When light hits these droplets, it is scattered and this results in a dense white background, called the atmospheric veil. As pointed in [1], Advanced Driver Assistance Systems (ADAS) based on the display of defogged images from a camera may help the driver by improving objects visibility in the image and thus may leads to a decrease of fatality and injury rates. In the last few years, the problem of single image defogging has attracted attention in the image processing community. Being an ill-posed problem, several methods have been proposed. However, a few among of these methods are dedicated to the processing of road images. One of the first exception is the method in [2], [1] where a planar constraint is introduced to improve the restoration of the road area, assuming an approximately flat road. The single image defogging problem being ill-posed, the choice of the Bayesian approach seems adequate to set this problem as an inference problem. A first Markov Random Field (MRF) approach of the problem has been proposed recently in [3]. However, this method is not dedicated to road images. In this paper, we propose a novel MRF model of the single image defogging problem which applies to all kinds of images but can also easily be refined to obtain better results on road images using the planar constraint. A comparative study and quantitative evaluation with several state-of-the-art algorithms is presented. This evaluation demonstrates that the proposed MRF model allows to derive a new algorithm which produces better quality results, in particular in case of a noisy input image.

Longer Is Better: Exploiting Path Diversity in Data Center Networks

Scipedia content — Thu, 28 Jan 2021 19:59:04 +0100

Data Center (DC) networks exhibit much more centralized characteristics than the legacy Internet, yet they are operated by similar distributed routing and control algorithms that fail to exploit topological redundancy to deliver better and more sustainable performance. Multipath protocols, for example, use node-local and heuristic information to only exploit path diversity between shortest paths. In this paper, we use a measurement-based approach to schedule flows over both shortest and non-shortest paths based on temporal network-wide utilization. We present the Baatdaat flow scheduling algorithm which uses spare DC network capacity to mitigate the performance degradation of heavily utilized links. Results show that Baatdaat achieves close to optimal Traffic Engineering by reducing network-wide maximum link utilization by up to 18% over Equal-Cost Multi-Path (ECMP) routing, while at the same time improving flow completion time by 41% - 95%.

Research on the Cooperation Method of Traffic Control and Route Guidance of Local Area Network

Scipedia content — Thu, 28 Jan 2021 19:58:01 +0100

The city traffic control system and traffic guidance system are two important subsystems of Intelligent Transportation Systems, also main means of the city traffic management. This paper studies the method of control and guidance system coordination for a specific local area, usually 2-6 signalized intersections, places a detailed analysis from the signal phase changes, guidance information display and other aspects of information to ensure the practical feasibility of the method. This paper presents a systematic approach to ensure interoperability in a variety of state regional road traffic running smoothly and orderly, reduce the incidence of congestion, to avoid further deterioration of the congestion, improving the efficiency of the vehicle access to and pass through the region.

Driving speed on thoroughfares in minor towns in Denmark

Scipedia content — Thu, 28 Jan 2021 19:53:19 +0100

Sammenhængen mellem trafikulykker og hastighed viser, at øget hastighed resulterer i flere og mere alvorlige trafikulykker. Tidligere undersøgelser har indikeret, at bilister overskrider hastighedsgrænsen på gennemfartsveje i mindre byer i Danmark. For at holde farten nede i bygennemfarter er der i Danmark traditionelt anvendt vejtekniske tiltag i form af bump, forsætninger og byporte. Formålet med denne undersøgelse er at finde ud af, hvilken effekt disse tiltag har på bilisters kørselsadfærd i gennemfartsbyer i Danmark. Undersøgelsen er foretaget på baggrund af GPS-baserede data fra kørende biler for 14 gennemfartsbyer i Nordjylland. Undersøgelsen viser, at enkeltstående bump og forsætninger kun har meget lokal effekt og ikke er tilstrækkelige til at holde bilisternes hastighed nede i byerne. Bilisterne øger hastigheden igen umiddelbart efter passagen af tiltaget. Kun hvor der er etableret bump og forsætninger efter Vejreglernes anbefalinger, er hastigheden reduceret, som ønsket. En tætliggende randbebyggelse reducerer også hastigheden i en del bygennemfarter, men den har ingen effekt på de højeste hastigheder. En modellering af effekter på hastighedsvalget viser, at uden hastighedsdæmpende foranstaltninger og en lav andel af byggeri nær bygennemfarten overskrides hastigheden ved ca. 75 % af passagerne. Endvidere har afstanden mellem hastighedsdæmpende tiltag stor betydning for hastighedsvalget, og randbebyggelsens karakter påvirker også hastighedsvalget i betydelig grad.

Electric Vehicle Performance and Consumption Evaluation

Scipedia content — Thu, 28 Jan 2021 19:49:01 +0100

In this article, the driving performance of two electric vehicles of the latest generation clean powertrain cars is evaluated. The vehicles under test are an electric Peugeot iOn, and an AGV electric version of the Ford Transit Connect. For different torque-speed operating conditions at wheel level, the vehicles are evaluated for their battery to wheel - electrical to mechanical - power conversion performance, with the help of chassis dynamometer testing. This generates an insight in the mapping of the consumption and efficiency value ranges for electric driving. The vehicles are also tested in real life on-road conditions, by following a pre-set representative track on public roads. Charging efficiency and consumption of auxiliaries is considered too. These tests give insight and realistic values to judge consumption, driving range and efficiency. With these results, further calculations and accurate simulations of realistic scenarios are possible

Document type: Article

Improving Traffic in Urban Environments applying the Wardrop Equilibrium

Scipedia content — Thu, 28 Jan 2021 19:48:31 +0100

Over the last few years vehicular traffic density has continuously increased and it is likely that the traffic demand will further increase in the future. In many metropolitan areas the road infrastructure is no longer able to handle the peak traffic demand and the existing road network cannot be easily extended. The best way to improve the traffic situation is to optimise the resources available in the transportation network and to coordinate the traffic demand. The approach that we propose in this paper makes use of a collaborative traffic coordination protocol which collects real-time Floating Car Data (FCD) directly from participating vehicles and suggests dynamic routes in order to minimize travel delay. Information such as speed, position and direction is sent to one or more Traffic Coordination Points (TCPs) where it is aggregated to obtain a global picture of the traffic conditions in real-time. Based on this data, we continuously compute the route that minimizes the travel time to a given destination by applying Wardrop's first principle of equilibrium. Our results show that, by coordinating the vehicles, we are able to better distribute the overall traffic demand throughout the transportation network, reducing the average travel times and accommodating more vehicles.

Model-based Optical Flow For Large Displacements and Homogeneous Regions

Scipedia content — Thu, 28 Jan 2021 19:46:27 +0100

International audience; Monocular motion analysis for advanced driver assistance systems (ADAS) is a very active research topic. However, two constraints limit the implementation of existent techniques in autonomous vehicles: poorly textured regions and large displacements due to vehicle egomotion that both lead to matching ambiguities. Coarse-to-ﬁne strategies are generally used to deal with large motion, but the lack of large texture makes this approach inefﬁcient to estimate road relative displacement. In this paper, we propose to assist the optical ﬂow process by exploiting both a 3D scene model and a rough velocity estimate from either other embedded sensors or egomotion estimations from the previous frames. Using the available a priori knowledge allows to compensate the dominant ﬂow to facilitate the estimation of the remaining part by a classical optical ﬂow method. We give results on both synthetic and real image sequences and compare our approach to other existing methods.

Integrated Demand Side Management of PHEVs using Event-Driven Dual Coordination

Scipedia content — Thu, 28 Jan 2021 19:43:17 +0100

the share of renewable electricity generation is expected to rise and plug-in (hybrid) electrical vehicles (PHEVs) are making inroads in the transport sector, there is a need to align increasing electricity demand with unpredicatable generation. Demand Side Management (DSM) is widely seen as one enabling technology and while many such mechanisms have been proposed, challenges remain regarding instantaneous control and communication. To address these, we propose an agent based dual coordination mechanism, which controls a fleet of PHEVs on two operation levels. The market operation level uses an existing timeslot-based algorithm to optimize energy allocation for discrete time steps. The real-time level translates this allocation into event-based control actions for a highly responsive environment, wherein a limited number of control messages can be exchanged. ispartof: pages:1-2 ispartof: Proceedings of the Fourth International Workshop on Agent Technologies for Energy Systems (ATES2013) pages:1-2 ispartof: Fourth International Workshop on Agent Technologies for Energy Systems location:Minnesota date:6 May - 6 May 2013 status: published

Online traffic-aware virtual machine placement in data center networks

Scipedia content — Thu, 28 Jan 2021 19:32:38 +0100

Data centers rely on virtualization to provide different services over a shared infrastructure. The placement of the different services and tasks in the physical machines is crucial for the performance of the whole system. A misplaced service can overload some network links, lead to congestion, or even connection disruptions. On the other hand, virtual machine migration allows reallocating services and changing the traffic matrix, leading to more efficient use of bandwidth. In this paper, we propose a Virtual Machine Placement (VMP) algorithm to (re)allocate virtual machines in the data center servers, based on the current traffic matrix, CPU, and memory usage. Analyzing the formation of community patterns in terms of traffic using graph theory, we are able to find virtual machines that are correlated because they exchange high amount of data. Those virtual machines are aggregated and allocated to servers as close as possible to each other, reducing traffic congestion. Our simulation results show that VMP was able to improve the traffic distribution. In some specific cases we were able to reduce 80% of the core traffic, concentrating it at the edge of the network.

Geographical Weather-Impact Sourcing: Analytical and Data-Driven Approaches

Scipedia content — Thu, 28 Jan 2021 19:32:05 +0100

The problem of weather-impact sourcing, i.e. identification and ranking of upstream National Airspace System (NAS) resources whose traffic flows are significantly impacted or modulated by a weather zone, is conceptualized. A historical case study is presented to gain insight into the geographical pattern of weather-impacted traffic. Based on these insights, we argue that highly simplified representations of air traffic and weather may be sufficient for weather-impact sourcing, and briefly introduce dataand modeldriven techniques that may be promising for rapid sourcing.

Influence of in-service degradation on strain localization in steel of main gas pipelines

Scipedia content — Thu, 28 Jan 2021 19:19:14 +0100

General regularities in the failure kinetics of steel of main gas pipelines (17GS) are established using the method of complete stress-strain curves, meanwhile in-service degradation of metals is taken into account. The influence of material degradation on material properties under static tensioning is considered using two independent approaches: the phenomenological model of damage accumulation in metals, and the fractographic analysis method. The accumulation of in-service damage is found to increase a degree of material opening and lead to partial “embrittlement” of the steel matrix due to the microdefects accumulation in the vicinity of metal cracking caused by hydrogenation.

‘Imma summis mutare’: landscape of light and shadow in the heart of the city – Porta Susa’ Railway Station, Turin

Scipedia content — Thu, 28 Jan 2021 19:10:38 +0100

The construction of the ‘New Passengers Building of Porta Susa’ in Turin, is the last act of a complex infrastructural, territorial, and urban plan that started in Turin in the second half of the 20th century. The succession of urban plans – technological, scientific implementation, and reorganization – is the scenery over which the will and innovative capacity of the city are projected. The dialogue between urban needs and functional reasons for the infrastructure are the basis and the objective of a many-decades-long project. The construction of an extraordinary ‘technological velarium’ is a simple and efficient idea: inundating the depth of a technological underground with light to make the route surface and the enclosed space an integral part of the public space. In its relational complexity, the station reestablishes and restores the break caused by the railway tracks and reconciles parts of the city divided by insurmountable barriers. Natural light, energy, collective, sustainable, and smart mobility are the keywords of a new urbanity that births and regenerates in the arriving and departing places.

Development and Series Application of a Vehicle Drivetrain Observer Used in Hybrid and Electric Vehicles

Scipedia content — Thu, 28 Jan 2021 19:08:55 +0100

This paper introduces the development and calibration process of a vehicle drivetrain observer used in hybrid and electric vehicles for active damping control (ADC) and for the improvement of the electric machine’s rotor angle signal quality. This approach starts with creating an overall vehicle model that includes the electric machine, the transmission, side shafts, the tires and the vehicle body. For control engineering purposes, that multi-order-model is then reduced into a two-mass-oscillator which can be easily described in state-space form. Using this reduced drivetrain model and applying a Luenberger observer approach, not only the signal quality of both the instrumented rotor angle and the speed of the electric machine can be improved considerably but also the oscillation dynamics of this vehicle drivetrain can be estimated. If not compensated during vehicle operation, drivetrain oscillations might lead to increased drivetrain wear, NVH issues and limited ride comfort

therefore, the oscillation speed is very important in computing an active damping torque that is to compensate drivetrain oscillations. Calibration of the vehicle drivetrain observer is done using specific vehicle test data that are fed into a standalone calibration tool identifying the parameters of the vehicle drivetrain as well as the Luenberger feedback vector. Based on these data, a proper active damping control application is set-up and verified in various vehicle tests and to lead to the calibration finally to the application in several hybrid and electric vehicle series projects (e.g. Peugeot 3008 HYbrid4).

Document type: Article

A Probabilistic Collocation Method Based Approach for Optimal Strategic Air Traffic Flow Management under Weather Uncertainties

Scipedia content — Thu, 28 Jan 2021 19:08:24 +0100

This paper suggests an effective approach to design optimal strategic air traffic management strategies under weather uncertainty. The approach is based on the multivariate probabilistic collocation method, which constructs a good low-order polynomial approximation of the original system mapping over likely parameter values, from which optimal management strategies can be derived. We illustrate the optimal management design procedure through an example of designing Minutesin-trail (MINIT) and routing strategies for two correlated weather zones. The performance analysis shows this approach is promising for the real-time design of strategic air traffic management strategies due to its correctness and efficiency.

Physical-layer communication recovery for heterogeneous network

Scipedia content — Thu, 28 Jan 2021 19:05:50 +0100

Natural and manmade disasters often cause failures in network components. Such failures induce communication service interruptions as well as packet and economic losses. To provide adequate communication recovery in disasters, we propose here a local fast failure recovery scheme, called Unaffected Alternate Selection (UAS), for avoiding traffic congestion and to achieve high survivability in the event of single link and router failures. Our simulation results show that the proposed scheme can successfully disperse affected traffic flow

Analysis of hazard areas associated with toxic cloud releases by pipelines

Scipedia content — Thu, 28 Jan 2021 19:05:13 +0100

The consequence assessment of a major accident involving a release of toxic gas by a pipeline is usually performed through the evaluation of the associated hazard area, which is an area where the concentration of the toxic substance exceeds a fi xed threshold level and induces harmful effects in people and the environment; its extension represents a signifi cant source of information required for the development of both safety and security strategies associated with dangerous pipelines. Since the threshold level adopted in the calculation strongly affects the extent of this hazard area, the purpose of this paper is to analyse such infl uence and the potential implications on the decisional process concerning prevention, preparedness and response actions in the case of major accidents. The paper describes the methodological approach adopted for this purpose, as well as the main results obtained using the threshold levels most commonly applied in the industrialized countries. Although the estimate of the hazard areas involves a high level of uncertainty, this study aims at supporting the development of pipeline safety and security strategies, thus increasing the overall safety level in this vital sector.

Future Problems in Logistics Due to Demographic Change

Scipedia content — Thu, 28 Jan 2021 19:01:31 +0100

This research paper describes the impact of demographic change on the transport and logistics sector. Therefore, besides a literature review and a management option discussion in the end, the paper contains the following two main sections and methods: First an empirical report of a 2014 survey conducted in the research project "DO.WERT" regarding the working conditions of truck drivers in Germany (working hours, wages, motivation, qualification; n=483). Second, an optimization prognosis (GAMS conceptualization) for the German truck driver labor market in 2030 including increased traffic volumes, restricted carbon dioxide emissions as well as a market-based wage cost function draft. Existing research has shown that major disruptions in the "triangle" of increasing traffic volumes, decreasing populations and also politically intended decreases in carbon dioxide emissions have to be expected, for example for logistics wage and also freight rates markets.

Urban logistics by rail and waterways in France and Japan

Scipedia content — Thu, 28 Jan 2021 18:56:51 +0100

This article aims to identify some commonalities and differences in intermodal freight in France and Japan, focusing on urban zones. This comparison puts into perspective two spatial situations linked with land pressure. It helps us identify opportunities for knowledge transfer of best practices for the promotion of modal shift and for land use and planning policies that favor intermodal freight. Research works have been carried out on intermodal logistic policies at national scales. However, in urban areas, the use of intermodal services has specific characteristics. Intermodal services are difficult to implement for last mile deliveries, as waterways and railways are used for high volume flows. Nevertheless, during the last decade, an increasing number of projects including intermodal services for the “mile before last” have been set up.

Document type: Conference object

Short-time Traffic Flow Prediction Method Based on Universal Organic Computing Architecture

Scipedia content — Thu, 28 Jan 2021 18:45:11 +0100

Designed a DNA-based genetic algorithm under the universal architecture of organic computing, combined particle swarm optimization algorithm, introduced a crossover operation for the particle location, can interfere with the particles speed, make inert particles escape the local optimum points, enhanced PSO algorithm's ability to get rid of local extreme point. Utilized improved algorithms to train the RBF neural network models, predict short-time traffic flow of a region intelligent traffic control. Simulation and error analysis of experimental results showed that, the designed algorithms can accurately forecast short-time traffic flow of the regional intelligent transportation control, forecasting effects is better, can be effectively applied to actual traffic engineering.

Analysing the role of rail in urban freight distribution

Scipedia content — Thu, 28 Jan 2021 18:43:35 +0100

Many different types of goods are transported to and delivered in cities, resulting in some urban freight challenges, such as increased vehicle movements within the city, collection of waste and one-way traffic flows towards the city. The growing urbanisation is expected to generate extra transport movements too. The European Transport White Paper states that national governments should try to implement policies to optimise freight transport in and around the city (European Commission, 2011). One option to do this is by using more sustainable transport modes. In that context, this research examines the potential role of rail in urban freight distribution, which was once important. Firstly, several existing cases of urban freight rail are discussed and compared. This results in the identification of success and failure factors. Secondly, a typology of cities and freight is set up. Thirdly, a conceptual cost model to estimate the potential of rail transport in urban freight distribution is proposed. The approach of this research consists of literature review and an expert meeting amongst academic and industry experts. The findings show that some relevant cases of urban freight rail exist in which different cities are involved. Knowledge of the different city and freight characteristics as well as the main success and failure factors is crucial. An appropriate methodology for assessing the potential of rail for urban freight distribution is a combination of stated and revealed preference and a social cost-benefit analysis.

Assessing the impacts of the JFK Ground Management Program

Scipedia content — Thu, 28 Jan 2021 18:39:03 +0100

The Ground Management Program at John F. Kennedy International Airport (JFK) aims to leverage the availability of comprehensive airport surface surveillance data and airline schedule information to better manage the taxi-out process, reduce taxi times, and improve efficiency. During periods when departure demand exceeds capacity, departing aircraft are held at the gate or another holding location, and released to the runway in time to join a short departure queue before taking off. As a result, aircraft absorb delay with engines off, and decrease their fuel burn, emissions, and engine maintenance costs. This paper evaluates data from before and after departure metering was initiated at JFK, to assess its impacts. The results show that airport performance has improved, and that the departure metering is responsible for a significant portion of the improvements. The paper also finds that the new, more automated, Ground Management Program that was implemented in April 2012 has continued to yield significant benefits. The average taxi-out time savings at JFK due to departure metering in the summer of 2012 is estimated to be about 1.5-2.7 minutes per flight.

Document type: Conference object

Lessons Learned from the Danish EV Living Lab

Scipedia content — Thu, 28 Jan 2021 18:34:19 +0100

The success of EVs in the marketplace will highly depend on the end-user acceptance. Insero E-Mobility has examined the user acceptance of EVs through a living lab study, where 80 Danish families used EVs for a period of 8-10 weeks as their only car. The study included a general test and identification of problems faced during usage as well as positive features of the EVs. Fleet potentials were additionally investigated with two trials in departments in Danish municipalities for 14 days. The living lab approach was used to reveal actual and latent needs as well as to facilitate innovation processes with the purpose of rendering input for product and business model development that will increase chance of end-user acceptance of EVs in the future. Long term public user trials has also in the case of the Danish EV Living Lab proven to provide comprehensive and rich amount of information on end customer needs and perceptions that can be used to define value across a range of attributes considered in vehicle purchasing decisions. Key conclusions are that 90% of families found that an EV could fulfil their demands but that range is an important issue even though it is mostly a psychological barrier. For fleets the EVs make sense to an extent depending on the predictability of driving behaviour and available infrastructure.

Document type: Article

Analysis and measurement of NOx emissions in port auxiliary vessels

Scipedia content — Thu, 28 Jan 2021 18:25:17 +0100

This paper is made NOx pollution emitted by port auxiliary vessels, specifically by harbour tugs, due to its unique operating characteristics of operation, require a large propulsion power changes discontinuously, also possess some peculiar technical characteristics, large tonnage and high propulsive power, that differentiate them from other auxiliary vessels of the port. Taking into account all the above features, there are no studies of the NOx emission engines caused by different working regimes of power because engine manufacturers have not measured these emissions across the range of operating power, but usually we only report the pollution produced by its engines to a maximum continuous power.

Document type: Article

A dynamic and automatic traffic light control system for solving the road congestion problem

Scipedia content — Thu, 28 Jan 2021 18:23:50 +0100

Electric vehicle possibilities using low power and light weight range extenders

Scipedia content — Thu, 28 Jan 2021 18:23:04 +0100

Electric cars have the disadvantage of a limited range, and drivers may experience a range anxiety. This range anxiety can be solved by adding a range extender. But, the range extender should be light so as not to significantly increase the weight of the original vehicle. In urban areas with dense traffic (usually developing countries), the average speed around cities is typically lower than 50km/h. This means, the rolling resistance losses are more important than aerodynamic losses, and a weight reduction results in a bigger electrical range. Therefore, smaller and lighter range extenders are of much interest. The contribution of this paper is to indicate the possibility of range extenders with less than 25 kg with a capacity of 150 to 200 cc to suit a condition where weight counts. In this paper, the cost, environmental and grid impacts of going electric are also discussed. The effect of high altitude and driving style on the performance of an electric vehicle is assessed. The challenges and opportunities of vehicle electrification between countries with decarbonated power generation and fossil fuel dominated power generation are highlighted. Throughout the article, the case of Ethiopia is taken as an example.

The Property Right Analysis And The Contract Governing About The Group Events Of Flight-delay

Scipedia content — Thu, 28 Jan 2021 18:21:40 +0100

The group events of flight-delay reports out the fact that when the time property rights can not be bounded completely, the passengers and airways always "look for a rent" in community field. In my opinion, to control the group events of flight-delay we should remove the community field or control the rent value and cost for rent. Comply with a long range, give more time property right of flight-delay to passenger is good to promote efficiency of deploying resources. The group events of flight-delay, caused by flight-delay, are some fierce language, body, and even legal conflicts between passenger groups and enterprises of air transport. A survey of Sichuan Shuangliu Airport shows that since August 2003 to August 2004 year, more than 40 group events were caused by flight-delay, and showed a gradual upward trend (1). Since it had a very negative impact on civil aviation normal operation and the image of the civil aviation industry, the group events of flight-delay has become the focus of air defense security control. Security could control for group events, reduce conflict loss based on crisis management. But the better way to reduce conflicts and improve resource utilization efficiency is contract governing.

DOE based high-performance gate-level pipelines

Scipedia content — Thu, 28 Jan 2021 18:13:04 +0100

Domino dynamic circuits are widely used in critical parts of high performance systems. In this paper we show that in addition to the functional limitation associated to the non-inverting behavior of domino gates, there are also performance disadvantages when compared to inverting dynamic gates, which can be related to this feature. These penalties rise from the fact that in order to produce a logic one, a non-inverting gate requires one or more of its inputs to be also at logic one. We analyze the operation of gate-level pipelines implemented with domino and with Delayed Output Evaluation (DOE), an inverting dynamic gate we have recently proposed, and compare their performance. Using domino and DOE gates similar in terms of delay, improvements in operating frequencies around 50% have been obtained by the DOE pipelines.

Peer reviewed

Document type: Conference object

V2X-d: A vehicular density estimation system that combines V2V and V2I communications

Scipedia content — Thu, 28 Jan 2021 18:12:43 +0100

© 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Road traffic is experiencing a drastic increase, and vehicular traffic congestion is becoming a major problem, especially in metropolitan environments throughout the world. Additionally, in modern Intelligent Transportation Systems (ITS) communications, the high amount of information that can be generated and processed by vehicles will significantly increase message redundancy, channel contention, and message collisions, thus reducing the efficiency of message dissemination processes. In this work, we present a V2X architecture to estimate traffic density on the road that relies on the advantages of combining V2V and V2I communications. Our proposal uses both the number of beacons received per vehicle (V2V) and per RSU (V2I), as well as the roadmap topology features to estimate the vehicle density. By using our approach, modern Intelligent Transportation Systems will be able to reduce traffic congestion and also to adopt more efficient message dissemination protocols. This work was partially supported by the Ministerio de Ciencia e Innovación, Spain, under Grant TIN2011-27543-C03-01, by the Fundación Universitaria Antonio Gargallo and the Obra Social de Ibercaja, under Grant 2013/B010, as well as the Government of Aragón and the European Social Fund (T91 Research Group). Barrachina Villalba, J.; Sangüesa, JA.; Fogue, M.; Garrido, P.; Martínez, FJ.; Cano Escribá, JC.; Tavares De Araujo Cesariny Calafate, CM.... (2013). V2X-d: a Vehicular Density Estimation System that combines V2V and V2I Communications. IEEE. doi:10.1109/WD.2013.6686518 S

GreenSwirl: Combining traffic signal control and route guidance for reducing traffic congestion

Scipedia content — Thu, 28 Jan 2021 18:11:48 +0100

Serious traffic congestion is a major social problem in large cities. Inefficient setting of traffic signal cycles, especially, is one of the main causes of congestion. Green Wave is a method for controlling traffic signals which allows one-way traffic to pass through a series of intersections without being stopped by a red light. Green Wave was tested in several cities around the world, but the results were not satisfactory. Two of the problems with Green Wave are that it still stops the crossing traffic, and it forms congestion in the traffic turning into or out of the crossing streets. To solve these problems, we propose a method of controlling traffic signals, GreenSwirl, in combination with a route guidance method, GreenDrive. GreenSwirl controls traffic signals to enable a smooth flow of traffic through signals times to turn green in succession and through non-stop circular routes through the city. The GreenWave technology is extended thereby. We also use navigation systems to optimize the overall control of the city's traffic. We did a simulation using the traffic simulator SUMO and the road network of Manhattan Island in New York. We confirmed that our method shortens the average travel time by 10%-60%, even when not all cars on the road are equipped to use this system.

Management and planning of water pipeline networks

Scipedia content — Thu, 28 Jan 2021 18:01:47 +0100

Water is a scare resource in the region of Middle East especially in Kuwait, where it has limited rainfall and natural ground water. Thus, Kuwait depends more than 90% on non-conventional water sources such as the seawater desalination, whereby the seawater is converted into fresh water through the desalination process. The desalination plants have been proven to supply sufficient amounts of fresh water throughout the years; however, some recent studies in Kuwait show a large amount of water leakages in the water pipeline network (WPN) and intermediate storage units. The wasted amount of water is very high if we consider the cost of producing water through the desalination process that it is roughly around 0.75 to 1.00 dollar per a cubic meter. Also, the up-to-date layout documentation of WPN is unavailable, where this situation poses a challenging problem in monitoring and inspecting WPN. This paper offers three contributions. First, we present a statistical analysis of the water production and consumption and the current status of WPN in Kuwait. Second, we describe an analytical approach to explore WPN based on the analogy between the computer network discovery and WPN discovery, wherein both the networks are viewed as a graph comprising of links and connectors. Third, we propose an integrated WPN discovery system that it deploys smart devices such as mobile robots to discover and validate the layouts of WPN. The manual detection of leakage is limited to surface pipelines, whereas the traditional techniques for passive detection of underground leakage are labor-intensive and very expensive. Thus, the proposed integrated WPN discovery system offers economical, long-term management and planning benefits over the manual inspection.

Integrating user experience validation into a new engineering development process for advanced driver assistance systems

Scipedia content — Thu, 28 Jan 2021 18:00:31 +0100

dvanced Driver Assistance Systems play a leading role in the revolution of cars; it has become a high priority for the automotive industry and now is no longer reserved for only premium cars. In this paper, a process is to be introduced, which allows to capture the User Experience (UX) already on the Model-in-the-Loop level (where only abstract models exist) to be fed back directly into the development process. This process allows for a more efficient work relationship between system development engineers and test & validation engineers. Furthermore the work in progress of a new tool is shown: MINARGUS. It allows a connection between a simulation model and the measurement of physiological data in one environment. The Advanced Active Cruise Control (Advanced ACC) system is used as a continuous example to support the paper.

VANET-enabled eco-friendly road characteristics-aware routing for vehicular traffic

Scipedia content — Thu, 28 Jan 2021 17:58:46 +0100

eer-reviewed The lack of significant breakthroughs in terms of alternative energy sources has caused both fuel consumption and gas emissions to constantly increase. In this context, improving fuel efficiency and reducing emissions in the transportation sector is vital, as vehicles are one of the important contributors to air pollution. This paper introduces EcoTrec, a novel eco-friendly routing algorithm for vehicular traffic which considers road characteristics such as surface conditions and gradients, as well as existing traffic conditions to improve the fuel savings of vehicles and reduce gas emissions. EcoTrec makes use of the Vehicular Ad-hoc NETworks (VANET) both for collecting data from distributed vehicles and to disseminate information in aid of the routing algorithm. The algorithm calculates the fuel efficiency of various routes and then directs the vehicle to a fuel efficient route, while also avoiding flash crowding. Simulation-based tests showed that by using EcoTrec, fuel emissions were significantly reduced, when compared with existing state-of-the-art vehicular routing algorithms.

Strategic airspace constraint analysis and environmental impact of Dynamic Weather Routes

Scipedia content — Thu, 28 Jan 2021 17:58:30 +0100

This paper presents analyses of the strategic airspace constraints and the environmental impact of Dynamic Weather Routes automation. The Dynamic Weather Routes are flight plans along which an aircraft can save a user-specified amount of wind-corrected flying time compared to the currently active flight plan. The strategic airspace constraints address sector congestion and Special Activity Area traversal along the two flight plans. The environmental impact considers fuel burn and emissions (e.g., hydrocarbons, carbon dioxide, etc.) along the two flight plans. A comparison of airspace constraints and emission values between the as-flown tracks of the aircraft and the suggested Dynamic Weather Route is presented. The results are for August 1 through October 31, 2012, when NASA's Dynamic Weather Routes software was running continuously at the American Airlines System Operations Center in Ft. Worth, TX. The results indicate that Dynamic Weather Routes not only save flying time and fuel, but help reduce traffic congestion and harmful emissions as well.

Liveability of Kuala Lumpur city centre from the perspective of urban design quality

Scipedia content — Thu, 28 Jan 2021 17:57:01 +0100

Creating a liveable city is commonly a debated question. Over the last decade, the total population of people living in urban areas has increased rapidly and is expected to continue rising until 2020 where urban sprawl is anticipated. As a result, higher density has led to a high crime rate and environmental issues as a result of traffic congestion and inefficiency of the public transportation system as well as industrialization. The Malaysian Government has undertaken many initiatives such as Government Transformation Program to create a quality environment for the residents. This demonstrates that liveability is one of the main concerns towards current new development and stressing the importance of creating a liveable city that provides a safe, healthy and enjoyable place of living. This initiative is probably the reason why Kuala Lumpur, the capital city of Malaysia is ranked 78th in the 2011 World Liveable City Ranking by the Economic Intelligence Units (EIU). The perception of the residents is the major contributing factor in creating a liveable place and environment because they are the real people who live, work and play in the city itself. So, it is essential to know the factors influencing the urban design quality of the city before implementing any guidelines or regulations regarding the liveability of a city. This paper discusses the policies regarding the liveability of Kuala Lumpur and how the happiness level of the urban design quality affects the liveability of the city itself.

A New Concept for Urban Logistics Delivery Area Booking

Scipedia content — Thu, 28 Jan 2021 17:54:49 +0100

This paper presents a research project named ALF (Aires de Livraison du Futur, Next Generation Delivery Areas). The project's purpose is to increase the use of delivery areas by prior booking by professional delivery operators, and make dynamic adjustment of their booking, if necessary. Information technologies with mobile communicating devices and in-roadway sensors are used in front of the information management process system. In this paper, the general context and the methodology used to handle the problem are introduced in a first part. The second part discusses the system architecture and the human interactions that allow users to book a delivery area for a given period. The third part describes the computational process allowing the delivery rounds preparation, with a solution based on distributed negotiation between multi-agents representing the delivery operators. The way this system allows dynamic adjustments of the proposed rounds is also described. The conclusion summarises main configurations of the system and lists innovative services which could be added to delivery areas and allow more efficiency for sustainable development of the cities.

Target-to-track collaborative association combining a laser scanner and a camera

Scipedia content — Thu, 28 Jan 2021 17:52:43 +0100

dvance Driver Assistance Systems designed to enhance safety require a perception module that should be reliable, robust and affordable. We propose a new cooperative fusion method between two exteroceptive sensors for the detection and tracking of obstacles. Focus is cast on the issue of data association of asynchronous measurements from multiple sensors of different nature. This perception and detection module is applied to local perception embedded on a host vehicle (the ego-vehicle) with two types of complementary sensors (laser scanner and mono-camera). The first detection stage is performed by the mono-layer laser scanner which provides a set of clustered impact points. Those clusters are filtered and projected into the image to define targets. Detected vehicles are tracked using an image registration algorithm. A multi-objects association and tracking algorithm based on belief theory is implemented to estimate the dynamic state of the tracks and to monitor appearance and disappearance of obstacles. Our approach does not make any assumption on the type of driving maneuver and is able to address highly non linear dynamic configuration. The method is applied on both real data and in simulated environment for the validation stage.

Charging/discharging process for electric vehicles: proposal and emulation

Scipedia content — Thu, 28 Jan 2021 17:46:44 +0100

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works This paper proposes a charging/discharging process for electric vehicles according to mode 4, specifically based on the CHAdeMO protocol. These initiatives will enable acceptably fast charging of EVs. The proposal has been designed and implemented within the Endesa Novare Vehicle to Microgrid project. As a first stage of the project, the charge/discharge process has been emulated before it will be developed in a real device. The emulation consists of two main parts: (i) an electric vehicle and its battery management system emulated by a microcontroller, and (ii) a charging/discharging device emulated by a computer application. Both parts communicate via CAN bus as it is done in existing protocols. The proposed control flow for charging and discharging and the results of the emulation are presented. Moreover, in order to be able to manage charge and discharge processes according to power network operator, a data model for both electrical vehicle and charging/discharging device according to standard IEC 61850-7-420 is also proposed.

Document type: Conference object

Combined electricity and water supply strategy for the department of water affairs

Scipedia content — Thu, 28 Jan 2021 17:45:38 +0100

In the recent years various Demand Side Management (DSM) projects were successfully completed on Department of Water Affairs (DWA) pump schemes. Each pump scheme consists of a number of pump stations which transfer water to power stations in the Mpumalanga Highveld area and municipal off-takes. The pump stations in a scheme are interconnected via rivers and pipe lines in order to transfer water from national key-point dams to different water users. Therefore, to manage the Highveld's water balance, all the interconnecting schemes work together to keep the important dams at a maximum operating level. Introducing load management on these sites, local- and regional strategies were developed and rolled out. Local strategies involve upgrades to existing pump stations, while regional strategies involve the interactions of the different pump schemes. With the completion of the local strategies, regional strategies for combined water balance and energy optimisation can be developed. By building a system that is more `visible', data is automatically collected. This will then be used to develop an advanced management strategy for the DWA. Therefore, in this article an overview is given on completed load management projects, planned future projects and the strategy to develop a combined electricity and water supply strategy for the DWA http://www.ieee.org/conferences_events/conferences/xplore_conference_proceedings.html

Vertical Grid Shifting Approach to the Development of Contrail Reduction Strategies with Sector Capacity Constraints

Scipedia content — Thu, 28 Jan 2021 17:39:09 +0100

Many strategies have been proposed to reduce contrail formation in the United States airspace. One approach is to build three-dimensional weather grids and have aircraft cruising at different flight levels to avoid the persistent contrail potential area with the consideration to constraints like fuel burn, flight level capacity, and total operations of climbing/descending aircraft count at each level. However, there is no air traffic control regulation defining the flight level capacity and the total number of climbing/descending aircraft operations for each flight level. This paper presents a contrail reduction scheme, which considers the defined Monitor Alert Parameter value as the sector capacity constraint. Instead of shifting (changing cruise altitude among vertical grids) for all aircraft in a center, the new scheme only shifts certain aircraft out of those grids that are within the persistent contrail potential area. Compared with the level shifting scheme, the grid shifting has a finer resolution and brings the benefits of more contrail reduction and less fuel burn. Furthermore, the one-hour planning interval is changed to one-minute, which provides higher temporal resolution in solution results. Numerical experiments are performed to compare the new vertical grid shifting scheme with the previous level shifting scheme.

Crowdsensing Maps of On-street Parking Spaces

Scipedia content — Thu, 28 Jan 2021 17:31:09 +0100

It has been estimated that traffic congestion costs the world economy hundreds of billions of dollars each year, increases pollution, and has a negative impact on the overall quality of life in metropolitan areas. A significant part of congestion in urban areas is due to vehicles searching for on-street parking. Detailed and accurate on-street parking maps can help drivers easily locate areas with large numbers of legal parking spaces and thus relieve congestion. In this paper, we address the problem of mapping street parking spaces using vehicles' preinstalled parking sensors. In particular, we focus on identifying legal parking spaces from crowdsourced data, whereas earlier work has largely assumed that such maps of legal spaces are given. We demonstrate that crowdsensing data from vehicle parking sensors can be used to classify on-street areas into legal/illegal parking spaces. Based on more than 2 million data points collected in Highland Park, NJ and downtown Brooklyn, NY areas, we show that on-street parking maps can be estimated with an accuracy of ~90% using proposed weighted occupancy rate thresholding algorithm.

A cooperative active blind spot assistant as example for next-gen cooperative driver assistance systems (CoDAS)

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

Vehicle-to-Vehicle communication has recently passed from a research topic to the subject of Field Operational Testing (FOT) and pilot deployment. Current state-of-the art Car-to-Car and Car-to-Infrastructure (C2X) functions will however only inform the driver, not interfere in actual vehicle operation. A logical next step after initial deployment will be sensor fusion to enhance actively intervening Advanced Driver Assistance Systems (ADAS) with information received over C2X. As the penetration rate of equipped vehicles increases over time, higher-level CoDAS functions become feasible. In this paper we present a concept for a cooperative active blind spot assistant (CABSA) as an exemplary function of these novel Cooperative Driver Assistance Systems. As the CABSA function improves an existing ADAS function, no negative effects are observed in low-penetration scenarios. The function was implemented with messages adhering European Telecommunications Standards Institute (ETSI) standards. Simulations and real-life tests show that the increase in operation range significantly expands the vehicle speed envelope upon which the system can prevent accidents compared to conventional blind-spot assistance.

A graph-based approach to nominal terminal routing

Scipedia content — Thu, 28 Jan 2021 17:01:42 +0100

the air transportation system moves toward trajectory-based operations, there is a greater need for route modeling, especially in the terminal airspace where traffic flows twist and turn and many do not follow any currently published route. This paper presents a graph-based algorithmic method for defining nominal terminal routing from historical flight tracks. First historical traffic is used to generate a directed graph. Then Djikstra's shortest path algorithm is used to identify the shortest yet most commonly used paths through the graph. There were many different nominal routes between different engine types due to the distinct differences in engine performance characteristics. A comparison of graph-based shortest path routes to two other methods (manual and k-means) showed how the method could rapidly produce similar distinct dominant terminal area flows. Finding shortest paths from all links of a sufficient weight, rather than just source nodes, identified more route options depicting standard path control techniques in addition to the dominant route. This method may be used to rapidly prototype route models to assess trajectory-based terminal area concepts.

The search for effective algorithms for recovery from loss of separation

Scipedia content — Thu, 28 Jan 2021 17:01:24 +0100

Our previous work presented an approach for developing high confidence algorithms for recovering aircraft from loss of separation situations. The correctness theorems for the algorithms relied on several key assumptions, namely that state data for all local aircraft is perfectly known, that resolution maneuvers can be achieved instantaneously, and that all aircraft compute resolutions using exactly the same data. Experiments showed that these assumptions were adequate in cases where the aircraft are far away from losing separation, but are insufficient when the aircraft have already lost separation. This paper describes the results of this experimentation and proposes a new criteria specification for loss of separation recovery that preserves the formal safety properties of the previous criteria while overcoming some key limitations. Candidate algorithms that satisfy the new criteria are presented.

Inland Ships for Efficient Transport Chains

Scipedia content — Wed, 27 Jan 2021 08:38:27 +0100

The European inland waterway transport sector is a highly competitive one. The transport operators in this sector are mainly small companies with only one ship. Such companies have very few possibilities to distinguish themselves from their competitors. At the same time their main asset, their ship, is often highly standardized. In this thesis, it is researched to which extent the small companies in the inland waterway transport sector can improve their competitive position. This is done by minimization of the required ship rate and total logistical cost through optimization of the main dimensions of inland ships. To achieve this aim, a ship design model is developed. This model is used to create large series of designs in which length, beam and draught are varied systematically. These designs are used to develop a set of rules of thumb for steel weight, lightweight, building cost and cargo carrying capacity of inland ships with any combination of length, beam and draught. The optimal dimensions of a ship are a function of the properties of the transport chain in which it operates and the waterway on which it sails. Therefore, a second model is developed that allows assessment of the required ship rate and total logistical cost as a function of the main dimensions of the ship and the most important properties of the transport chain and the waterway. Finally, through an extensive scenario analysis flow charts are developed that allow estimation of the optimal ship dimensions as a function of the properties of the transport chain, the cargo type and the water depth.

Improving Bus Service with Dynamic Holding Control: from Theory to Practice

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

Service unreliability is widely recognized as one of the main deterrents for travelers to use buses as their primary mode of transportation. Bus systems are exposed to an adverse feedback loop that generates a tendency for buses to fall out of sync. This tendency can be counteracted by the application of control strategies that regulate the motion of the buses. Even though this is well known among transit operators and research has been devoted to solve this issue, in practice most bus systems rely on static control methods that ignore the real conditions of the system. Unfortunately, such an approach slows buses down excessively and it cannot compensate for severe disruptions.This research proposes a control method that applies dynamic holding based on real-time conditions, in order to synchronize the buses' motion and improve their service reliability without imposing an excessive burden on their speed. A formulation that improves and simplifies existing dynamic holding control strategies for isolated bus lines is developed. Stability conditions both for headway and schedule deviations are then derived, and the theoretical results are validated with a simulation case study. The improved formulation is then extended to corridors where multiple bus lines overlap, reproducing the stability results found in the single line scenario. A framework for a real application entailing a distributed system of on-board devices is also presented. The control performance is then validated, now using a real-world case study. Finally, the robustness of this control framework is assessed considering the effects of possible device failures. In particular, the effects of GPS malfunctions on the on-board devices are studied analytically, revealing the resilience of the proposed control strategy.

Effects of dynamic speed limit strategies on capacity at freeway bottlenecks

Scipedia content — Tue, 26 Jan 2021 18:18:49 +0100

Projecte realitzat en el marc d’un programa de mobilitat amb Eidgenössische Technische Hochschule Zürich

The objective of this Thesis is to understand the situation of a catalan highway with VSL strategies through empirical data of one day. It will be done using standard traffic tools to make the congested and uncongested states analysis. The Thesis will involve: visual identification of congested areas, bottleneck detection and diagnostic, identification of fundamental diagrams, lane density and speed distribution and comparison between speed limits and measured speeds. In addition, it will give recommendations and establish the basis for a future set of experiments to investigate VSL strategies in deep. The main findings are the detection of five bottlenecks, many lane changes near the ramps and the change of occupancy distribution between lanes in congested periods. After a careful and detailed analysis of the data we can conclude that VSL is not as effective as it should be. That is caused by the algorithm it uses and the fact that drivers disobey speed limits.

Development and Simulation of Increased Generation on a Secondary Circuit of a Microgrid

Scipedia content — Tue, 26 Jan 2021 18:14:49 +0100

fossil fuels are depleted and their environmental impacts remain, other sources of energy must be considered to generate power. Renewable sources, for example, are emerging to play a major role in this regard. In parallel, electric vehicle (EV) charging is evolving as a major load demand. To meet reliability and resiliency goals demanded by the electricity market, interest in microgrids are growing as a distributed energy resource (DER). In this thesis, the effects of intermittent renewable power generation and random EV charging on secondary microgrid circuits are analyzed in the presence of a controllable battery in order to characterize and better understand the dynamics associated with intermittent power production and random load demands in the context of the microgrid paradigm.For two reasons, a secondary circuit on the University of California, Irvine (UCI) Microgrid serves as the case study. First, the secondary circuit (UC-9) is heavily loaded and an integral component of a highly characterized and metered microgrid. Second, a unique "next-generation" distributed energy resource has been deployed at the end of the circuit that integrates photovoltaic power generation, battery storage, and EV charging.In order to analyze this system and evaluate the impact of the DER on the secondary circuit, a model was developed to provide a real-time load flow analysis. The research develops a power management system applicable to similarly integrated systems. The model is verified by metered data obtained from a network of high resolution electric meters and estimated load data for the buildings that have unknown demand. An increase in voltage is observed when the amount of photovoltaic power generation is increased. To mitigate this effect, a constant power factor is set. Should the real power change dramatically, the reactive power is changed to mitigate voltage fluctuations.

Advising and Optimizing the Deployment of Sustainability-Oriented Technologies in the Integrated Electricity, Light-Duty Transportation, and Water Supply System

Scipedia content — Tue, 26 Jan 2021 17:57:56 +0100

The convergence of increasing populations, decreasing primary resource availability, and uncertain climates have drawn attention to the challenge of shifting the operations of key resource sectors towards a sustainable paradigm. This is prevalent in California, which has set sustainability-oriented policies such as the Renewable Portfolio Standards and Zero-Emission Vehicle mandates. To meet these goals, many options have been identified to potentially carry out these shifts. The electricity sector is focusing on accommodating renewable power generation, the transportation sector on alternative fuel drivetrains and infrastructure, and the water supply sector on conservation, reuse, and unconventional supplies. Historical performance evaluations of these options, however, have not adequately taken into account the impacts on and constraints of co-dependent infrastructures that must accommodate them and their interactions with other simultaneously deployed options. These aspects are critical for optimally choosing options to meet sustainability goals, since the combined system of all resource sectors must satisfy them. Certain operations should not be made sustainable at the expense of rendering others as unsustainable, and certain resource sectors should not meet their individual goals in a way that hinders the ability of the entire system to do so. Therefore, this work develops and utilizes an integrated platform of the electricity, transportation, and water supply sectors to characterize the performance of emerging technology and management options while taking into account their impacts on co-dependent infrastructures and identify synergistic or detrimental interactions between the deployment of different options. This is carried out by first evaluating the performance of each option in the context of individual resource sectors to determine infrastructure impacts, then again in the context of paired resource sectors (electricity-transportation, electricity-water), and finally in the context of the combined tri-sector system. This allows a more robust basis for composing preferred option portfolios to meet sustainability goals and gives a direction for coordinating the paradigm shifts of different resource sectors. Overall, it is determined that taking into account infrastructure constraints and potential operational interactions can significantly change the evaluation of the preferred role that different technologies should fulfill in contributing towards satisfying sustainability goals in the holistic context.

Assessing the quality of public transport from the perspective of sustainable mobility: the case of Fortaleza

Scipedia content — Tue, 26 Jan 2021 17:54:41 +0100

Este trabalho apresentou um método de avaliação para sistemas de transporte público de uma cidade e da região metropolitana à qual ele pertence. No caso específico deste estudo, a cidade selecionada foi Fortaleza. A avaliação foi realizada do ponto de vista retrospectivo (1992, 2000 e 2010) e prospectivo (2014), com o propósito de destacar a importância da abordagem para o planejamento da mobilidade sustentável. A pesquisa foi motivada pelos crescentes problemas de mobilidade enfrentados pela população nos últimos anos. Projetos de ampliação da infraestrutura viária, bem como de criação de novos sistemas de transportes públicos são propostos com frequência, mas estes raramente são totalmente implantados ou executados. A estratégia de avaliação se baseia no Índice de Mobilidade Urbana Sustentável (IMUS), criado por Costa (2008). A estrutura do índice envolve 87 indicadores, que visam refletir diferentes impactos e perspectivas da mobilidade. Como o foco do estudo foi o transporte público, foram calculados apenas os 22 indicadores diretamente ligados ao tema. Os pesos da estrutura hierárquica foram redistribuídos para o índice resultante, que passou a ser chamado de IMUS-TP. O valor do índice foi calculado para cada um dos quatro anos do período de análise, de forma a avaliar os respectivos níveis de mobilidade urbana sustentável. Em geral, os resultados mostraram melhorias nos valores dos indicadores ao longo do tempo. Alguns indicadores, no entanto, apresentaram problemas. Isto produziu efeitos negativos sobre os valores do índice encontrados para Fortaleza (IMUS-TP, igual a 0,463) e para a região metropolitana (IMUS-TP-RMF, igual a 0,407) em 2010. Mesmo considerando todos os projetos previstos para 2014, os valores de IMUS-TP e IMUS-TP-RMF deverão chegar a apenas 0,612 e 0,500, respectivamente. Estes valores não são altos, mas eles certamente mostram melhorias no sistema de transporte público. Algumas das melhorias esperadas são: priorização do transporte público, investimentos na integração dos sistemas de transporte, subsídios públicos para o sistema de transporte metropolitano, mais interação entre os sistemas de transporte urbano e metropolitano, e procedimentos eficazes para a atualização dos bancos de dados. Os valores do índice mostram que estas medidas, embora importantes porque melhorarão as condições de mobilidade na cidade de Fortaleza e na região metropolitana, não resolverão definitivamente o problema. This study introduces a method for the assessment of the public transportation systems of a single city and also of the metropolitan region it belongs to. In the case of this particular investigation, the selected city was Fortaleza, Brazil. The evaluation was conducted for three periods in the past (i.e., the years 1992, 2000, and 2010), and one in the future, which is the year 2014. The purpose was to highlight the importance of the approach for sustainable mobility planning. The growing mobility problems faced by the population in the recent past have been the motivation for this research. Projects for road infrastructure improvement and for the creation of new public transportation systems are frequently proposed, but rarely built or fully implemented. The evaluation approach is based on the Index of Sustainable Urban Mobility (I_SUM or IMUS, in Portuguese) created by Costa (2008). The index framework involves 87 indicators, which are meant to cover distinct impacts and perspectives of mobility. As the focus of the study was on public transportation, only the 22 indicators directly linked to the subject were calculated. The weights of the hierarchical structure were redistributed to the resulting index, which was then called IMUS-TP. The index value was calculated for each of the four years period of analysis, for assessing the respective levels of sustainable urban mobility. In general, the results showed improvements in the values of the indicators throughout time. Some indicators, however, had problems. This had a negative effect on the index values found for Fortaleza (IMUS-TP, equal to 0.463) and for the metropolitan region (IMUS-TP-RMF, equal to 0.407) in 2010. Even considering all projects proposed for 2014, the values of IMUS-TP and IMUS-TP-RMF are expected to reach only 0.612 and 0.500, respectively. These values are not high, but they certainly show improvements in the public transportation system. Some of the expected improvements are: priorization of public transport, investments in the integration of transport systems, public subsidies to the metropolitan transit system, more interaction between urban and metropolitan transit systems, and effective procedures for the update of databases. The index values show that these measures, although important because they will improve the mobility conditions in the city of Fortaleza and in the metropolitan region, will not be able to definitely solve the problem.

Sistema híbrido de armazenamento de energia para aplicação em veículos elétricos

Scipedia content — Tue, 26 Jan 2021 17:51:50 +0100

Orientador: José Antenor Pomilio Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Made available in DSpace on 2018-08-26T07:38:59Z (GMT). No. of bitstreams: 1 Avelino_WellingtondeOliveira_M.pdf: 7672293 bytes, checksum: 3534b3ead7d65fe436c7a493ca065d49 (MD5) Previous issue date: 2014 Resumo: Este trabalho propõe um sistema de armazenamento de energia híbrido composto por bateria e ultracapacitor para aplicações em veículos elétricos, baseado em uma estratégia de controle que possui o intuito de combinar especialidades de múltiplas fontes que diferem em termos de densidade de energia e de densidade de potência. O sistema atua gerenciando o fluxo de potência entre os dispositivos de suprimento de energia, permitindo eficiência energética necessária para um bom desempenho do sistema de propulsão do veículo elétrico. O sistema também permite o fluxo bidirecional de potência, possibilitando o veículo atuar com frenagem regenerativa. Um conveniente arranjo entre as fontes, juntamente com o gerenciamento de energia permitiu reduzir os requisitos de dimensionamento da bateria que funciona como fonte de maior densidade de energia. Adicionalmente, a vida útil destas fontes e a imunidade do sistema de suprimento a variações bruscas de demanda de potência são melhoradas. A integração do sistema do sistema de gerenciamento implementado em um conversor de potência de 12 kW a um kart indoor elétrico permitiu validar o sistema e analisar experimentalmente o desempenho do veículo, comprovando a eficácia da estratégia de controle Abstract: This work proposes a hybrid energy storage system for applications on electric vehicles, based on a control strategy that combines multiple power sources with different characteristics in terms of energy density and power density. The system manages energy flow among the storage devices, providing necessary energetic efficiency to guarantee high performance for vehicular propulsion system. In addition, the system permits bidirectional power flow, providing regenerative braking for the vehicle. Convenient organizations among power sources, working with energy management have permitted to reduce requirements for the battery that works as higher energy density power source. At the same time, lifetime for these energy storage devices and immunity for sudden variations are improved. The integration of the power management system implemented in a power converter of 12 kW to an electric indoor kart allowed to validate experimentally and analyze the performance of the vehicle, proving the effectiveness of the control strategy Mestrado Energia Eletrica Mestre em Engenharia Elétric

The New Suburbs: Evolving travel behavior, the built environment, and subway investment in Mexico City

Scipedia content — Tue, 26 Jan 2021 17:50:10 +0100

Mexico City is a suburban metropolis, yet most of its suburbs would be unfamiliar toÂ urbanists accustomed to thinking about US metropolitan regions. Mexico Cityâ€™s suburbs areÂ densely populatedâ€”not thinly settledâ€”and its residents rely primarily on informal transit ratherÂ than privately-owned automobiles for their daily transportation. These types of dense and transitdependentÂ suburbs have emerged as the fastest-growing form of human settlement in citiesÂ throughout Latin America, Asia, and Africa. Wealthier and at a later stage in its economicÂ development than other developing-world metropolises, Mexico City is a compelling place toÂ investigate the effects of rising incomes, increased car ownership, and transit investments in theÂ dense, peripheral areas that have grown rapidly around informal transit in the past decades, andÂ is a bellwether for cities like Dakar, Cairo, Lima, and Jakarta. I begin this dissertation with a historical overview of the demographic, economic, andÂ political trends that have helped shape existing urban form, transportation infrastructure, andÂ travel behavior in Mexico City. Despite an uptick in car ownership and use, most householdsâ€”both urban and suburbanâ€”continue to rely on public transportation. Furthermore, suburbanÂ Mexico City has lower rates of car ownership and use than its central areas. In subsequentÂ chapters, I frame, pose, and investigate three interrelated questions about Mexico Cityâ€™s evolvingÂ suburban landscape, the nature of householdsâ€™ travel decisions, and the relationship between theÂ built environment and travel behavior. Together, these inquiries tell a story that differsÂ significantly from narratives about US suburbs, and provide insight into the future transportationÂ needs and likely effects of land and transportation policy in these communities and others likeÂ them in Mexico and throughout the developing world. First, how has the influence of the built environment on travel behavior changed as moreÂ households have moved into the suburbs and aggregate car use has increased? Using two largeÂ metropolitan household travel surveys from 1994 and 2007, I model two related-but-distinctÂ household travel decisions: whether to drive on an average weekday, and if so, how far to drive.Â After controlling for income and other household attributes, I find that the influence ofÂ population and job density on whether a household undertakes any daily car trips is strong andÂ has increased marginally over time. By contrast, high job and population densities have a muchÂ smaller influence on the total distance of weekday car travel that a household generates. For theÂ subset of households whose members drive on a given weekday, job and population densitiesÂ have no statistical effect at all. Contrary to expectations, a householdâ€™s distance from the urbanÂ center is strongly correlated with a lower probability of driving, even after controlling forÂ income. This effect, however, appears to be diminishing over time, and when members of aÂ household drive, they drive significantly more if they live farther from the urban center. TheÂ combination of informal transit, public buses, and the Metro has provided sufficient transitÂ service to constrain car use in the densely populated suburban environments of Mexico City.Â Once suburban residents drive, however, they tend to drive a lot regardless of transit or theÂ features of the built environment. Second, how much are the recent trends of increased suburbanization, rising carownership,Â and the proliferation of massive commercially-built peripheral housing developmentsÂ interrelated? To investigate this question, I first disentangle urban growth and car ownershipÂ trends by geographic area. The fastest-growing areas tend to be poorer and have had a muchÂ smaller impact on the size of the metropolitan car fleet than wealthier, more establishedÂ neighborhoods in the center and western half of the metropolis. I then zoom in to examineÂ several recent commercial housing developments. These developments, supported by publiclysubsidizedÂ mortgages, contain thousands of densely-packed, small, and modestly-priced housingÂ units. Their residents remain highly reliant on public transportation, particularly informal transit,Â and the neighborhoods become less homogenous over time as homeowners convert units andÂ parking spaces to shops and offices. Finally, I use the 2007 household travel survey to modelÂ householdsâ€™ intertwined decisions of where to live and whether to own a car. As expected,Â wealthier and smaller households are more likely to purchase vehicles. However, they prefer toÂ live in more central areas where households with cars tend to drive shorter distances. If housingÂ policy and production cannot adapt to provide more centrally-located housing, growing incomesÂ will tend to increase car ownership but concentrate more of it in areas where car-owningÂ households drive much farther. Third, how has the Metroâ€™s Line B, one of the first and only suburban high-capacityÂ transit investments, influenced local and regional travel behavior and land use? To explore thisÂ question, I compare travel behavior and land use measures at six geographic scales, including theÂ investmentâ€™s immediate catchment area, across two time periods: six years before and sevenÂ years after the investment opened. Line B, which opened in stages in 1999 and 2000,Â significantly expanded Metro coverage into the densely populated and fast-growing suburbanÂ municipality of Ecatepec. While the investment sparked a significant increase in local Metro use,Â most of this increase came from people relying on informal transit, rather than cars. While thisÂ shift reduced transit fares and increased transit speeds for local residents, it also increasedÂ government subsidies for the Metro and had no apparent effect on road speeds. Furthermore, theÂ Metro remains highly dependent on informal transit to provide feeder service even withinÂ Ecatepec. In terms of land use, the investment increased density around the stations but appearsÂ to have had little to no effect on downtown commercial development, where it might have beenÂ expected to have a significant influence. In short, the effects of Line B demonstrate much of theÂ promise and problem with expanding high capacity transit service into the suburbs. Ridership isÂ likely to be high, but so too will be the costs and subsidies, while the effects on car ownershipÂ and urban form are likely to be modest. Individually, each chapter contributes to a specific body of transportation and planningÂ literature drawn from the US as well as developing countries. Collectively, they point toÂ connection between land use and transportation in Mexico City that is different from theÂ connection in US and other rich-world cities. In particular, there is a physical disconnect betweenÂ the generally suburban homes of transit users and the generally central location of high-capacityÂ public transit. Addressing this disconnect by shifting housing production from the periphery toÂ the center or by expanding high-capacity transit to the periphery would require significantÂ amounts of time and public subsidy. Thus, contemporary policies to reduce car use or increaseÂ accessibility for the poor in the short and medium term would do well to focus on improving theÂ flexible, medium-capacity informal transit around which the cityâ€™s dense and transit-dependentÂ suburbs have grown and continue to grow.

Transit-Oriented Development in China: How can it be planned in complex urban systems?

Scipedia content — Tue, 26 Jan 2021 17:48:16 +0100

In recent years most of the Chinese cities have shown a rapid decline in modal split of public transport as a consequence of rapid urbanization and motorization in the “socialist market economy”. It has been witnessed that cars flood into streets; road congestion, air pollution and traffic safety have become major problems in urban China. To ameliorate this situation and to promote sustainable urban traffic, many Chinese metropolises consider the concept of Transit-Oriented Development (TOD), which is a model with worldwide successful experience in promoting public transport through integrating urban traffic with land use and creating a mobility environment where public transport is a much more respectable alternative to automobile travel. However, as the municipal governments embrace the concept, they were not aware of the fact that the realization of TOD requires fulfilling a number of preconditions, including a high level of land use diversity and density, beautiful urban design and cityscape, constraints on automobile use, good transit service qualities, good urban governance, and a real estate market that provides affordable and mixed types of housing. Even if the governments are informed of these conditions and seriously intend to meet these conditions, they are bound to deliberately enact comprehensive targeted policies and to mobilize substantial resources and support. However, after decades of economic reforms the Chinese cities have grown from comparatively simple systems that heavily depend on artificial intervention to complex and self-organizing systems that seem to be unplannable. In other words, it is very likely nowadays for the deliberate design for TOD to become dashed in complex cities. Therefore, rather than focusing on providing policy instruments and implementation recommendations of TOD for the Chinese local governments, this study sought to understand how cities are structured, what makes cities work, how to perceive cities as complex systems, and with such a perception how to plan cities (with respect to TOD). Accordingly, this book aims to pry open the complex urban systems firstly by formulating a conceptual model of cities and establishing 36 city parameters; and secondly by applying this framework into the case area, the Dalian city that is one of the most prosperous cities located in the eastern coastal region of China and has officially adopted TOD, whereby the empirical scores of the parameters are obtained. Based on the empirical scores, we draw lessons as to how the city parameters operate, how complex urban systems self-organize, and then what the implications are for deliberate design. The purpose of the lessons is to show elite politicians, policy analysts, public officials, legalists and also the wider public how TOD can be planned in contemporary cities in China.

Testing the usability of OpenStreetMap's iD tool

Scipedia content — Tue, 26 Jan 2021 17:47:22 +0100

von Jan Bastian Behrens Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers Wien, Techn. Univ., Dipl.-Arb., 2014

Προηγμένα συστήματα υποβοήθησης οδηγού με μεθόδους υπολογιστικής όρασης

Scipedia content — Tue, 26 Jan 2021 17:46:47 +0100

Τα αυτοκινητιστικά δυστυχήματα αποτελούν μια από τις κυριότερες αιτίες θανάτου παγκοσμίως. Ο αυξανόμενος αριθμός τους οδήγησε στην συνειδητοποίηση ότι η χρήση προηγμένης τεχνολογίας για την κατασκευή ασφαλέστερων οχημάτων είναι απαραίτητη για την μείωση των ατυχημάτων και κατά συνέπεια των θανάτων που οφείλονται σε αυτά. Από τη στιγμή που οι τεχνολογικές εξελίξεις επέτρεψαν την ενσωμάτωση φθηνών, χαμηλής κατανάλωσης συστημάτων με μεγάλη επεξεργαστική ταχύτητα σε οχήματα, κατέστη προφανές ότι περίπλοκες τεχνικές υπολογιστικής όρασης μπορούσαν πλέον να χρησιμοποιηθούν για την υποβοήθηση της οδήγησης. Σε αυτή την κατεύθυνση, η παρούσα διατριβή εστιάζει στην ανάπτυξη καινοτόμων λύσεων για διαφορετικά κομμάτια που εμπλέκονται στα προηγμένα συστήματα υποβοήθησης του οδηγού. Πιο συγκεκριμένα, σε αυτή την διατριβή προτείνονται καινοτόμα υποσυστήματα για την αναγνώριση σημάτων οδικής κυκλοφορίας, την αναγνώριση φωτεινών σηματοδοτών, τον εντοπισμό προπορευόμενου οχήματος και τον εντοπισμό δρόμου. Οι τεχνικές που χρησιμοποιήθηκαν για την ανάπτυξη των προτεινόμενων λύσεων βασίζονται στην χρωματική επεξεργασία εικόνας με έμφαση στην ανεξαρτησία από την φωτεινότητα της σκηνής, στην χρήση πληροφορίας συμμετρίας για τον εντοπισμό χαρακτηριστικών αντικειμένων (όπως σήματα οδικής κυκλοφορίας, φωτεινοί σηματοδότες και οχήματα), στην χώρο-χρονική παρακολούθηση των εντοπισμένων αντικειμένων και στην αυτόματη κατάτμηση εικόνας για τον εντοπισμό δρόμου. Τα προτεινόμενα συστήματα αναπτύχθηκαν με στόχο την ανθεκτικότητα σε αλλαγές της φωτεινότητας ή τις καιρικές συνθήκες, καθώς και στην οδήγηση σε απαιτητικά περιβάλλοντα. Επίσης, έχει δοθεί ιδιαίτερη έμφαση στην προοπτική υλοποίησης συστημάτων πραγματικού χρόνου. Τα αποτελέσματα που παρουσιάζονται σε αυτή την διατριβή αποδεικνύουν την ανωτερότητα των προτεινόμενων μεθόδων έναντι αντίστοιχων της σχετικής βιβλιογραφίας, ειδικά στις περιπτώσεις του εντοπισμού προπορευόμενου οχήματος και του εντοπισμού δρόμου. Ελπίζουμε ότι μέρη της έρευνας αυτής θα εμπνεύσουν νέες προσεγγίσεις για τις μελλοντικές υλοποιήσεις αντίστοιχων συστημάτων. Traffic accidents are one of the main reasons for the loss of human lives worldwide. Their increasing number has led to the realization that the use of advanced technology for manufacturing safer vehicles is imperative for limiting casualties. Since technological breakthroughs allowed the incorporation of cheap, low consumption systems with high processing speeds in vehicles, it became apparent that complex computer vision techniques could be used to assist drivers in navigating their vehicles. In this direction, this thesis focuses on providing novel solutions for different tasks involved in advanced driver assistance systems. More specifically, this thesis proposes novel sub-systems for traffic sign recognition, traffic light recognition, preceding vehicle detection and road detection. The techniques used for developing the proposed solutions are based on color image processing with a focus on illumination invariance, using symmetry information for man-made objects (like traffic signs, traffic lights and vehicles) detection, spatiotemporal tracking of detected results and automated image segmentation for road detection. The proposed systems were implemented with a goal of robustness to changes of illumination and weather conditions, as well as to diverse driving environments. A special focus on the prospect for real-time implementation has also been given. The results presented in this thesis indicate the superiority of the proposed methods to their counterparts found in relevant literature in both normal and challenging conditions, especially in the cases of preceding vehicle detection and road detection. Hopefully, parts of this research will provide new insights for future developments in the field of intelligent transportation.

Driving electric ? : a financial assessment of electric vehicle policies in France

Scipedia content — Tue, 26 Jan 2021 17:44:37 +0100

u cours des années récentes, les véhicules électriques sont revenus sur le devant de la scène des politiques publiques en matière de transport. Considérés comme un remède possible à diverses préoccupations pressantes des pouvoirs publics, ils bénéficient d'un soutien croissant de leur part. De telles mesures de soutien demeurent contestées : en effet, leur impact sur le décollage effectif des ventes, leur soutenabilité, leur utilité et leur justification sont loin d'aller de soi. Cette étude vise à éclairer l'impact des politiques publiques destinées à influencer la demande sur i) le taux de pénétration des véhicules électriques auprès des ménages français, et ii) les finances publiques. Dans un premier temps sera brossé le tableau du contexte dans lequel les véhicules électriques ont vocation à se développer. Il sera proposé un panorama large des opportunités potentielles offertes par l'introduction des véhicules électriques. Une revue internationale des politiques publiques est conduite, qui décrit les leviers de politique publique qui sont aujourd'hui actionnés en soutien au véhicule électrique de par le monde. L'accent y est mis sur les mesures destinées à agir sur la demande. Des conclusions préliminaires seront proposées sur l'efficacité de ces mesures au regard des taux observés de pénétration du véhicule électrique. Dans un deuxième temps, l'étude s'attache à évaluer le marché potentiel des véhicules électriques auprès des ménages français. L'analyse porte non seulement sur les déterminants financiers de la demande, mais aussi sur les obstacles socio-économiques à l'adoption des véhicules électriques par ces ménages. S'appuyant sur une analyse par scénarios qui permet de rendre compte des nombreuses incertitudes relatives aux évolutions à prévoir des véhicules, des coûts et des tendances de marché, une prévision du potentiel de demande à l'horizon 2023 est avancée. L'approche désagrégée qui est appliquée à partir de la base de données de l'Enquête Nationale Transports et Déplacements 2007/2008 permet d'identifier les combinaisons de instruments financiers de politique publique les plus à même de garantir certains niveaux de pénétration du véhicule électrique dans la prochaine décennie. Enfin, l'impact sur les finances publiques du remplacement d'un véhicule conventionnel par un véhicule électrique est étudié. L'analyse porte à la fois sur les phases de production et d'usage du véhicule. Le modèle d'évaluation développé à cet effet tient compte des impacts directs et indirects sur les finances publiques. Sont pris en compte les subventions directes à l'achat, les allègements fiscaux, les recettes fiscales, ainsi que les effets sur l'emploi. Les conclusions et observations tirées de l'étude permettent de formuler diverses suggestions à l'attention des constructeurs automobiles et des décideurs publics affichant la volonté de soutenir l'essor du véhicule électrique. In recent years, electric vehicles have come to the forefront of public transport policies. They are seen as remedy for various pressing public concerns and are thus increasingly benefiting from supportive policy measures. Such measures remain contested: their impact on actual vehicle uptake rates, their sustainability, usefulness and justification are far from being self-evident. This study aims at uncovering the effect of financial demand-side public policy measures on i) the uptake rate of electric vehicles among private households in France, and ii) the public budget. First, the context within which electric vehicles are to evolve is sketched. A comprehensive overview of the potential opportunities that come with the introduction of electric vehicles is given. An international policy review depicts public policy levers that are currently deployed in order to support the uptake of electric vehicles. A focus is put on financial demand-side measures. Preliminary conclusions on their effectiveness with regards to observed electric vehicle uptake rates in the various countries reviewed are drawn. Next, the potential market for electric vehicles among French households is explored. Besides financial aspects, socio-economic obstacles to electric vehicle uptake among private households are analysed. With the aid of scenario analysis that accounts for the many uncertainties with regards to future vehicle developments, costs and market trends, a forecast of the electric vehicles' potential up until 2023 is given. The applied disaggregate approach based on the database of the French National Transport Survey 2007/2008 allows identifying the most promising sets of financial public policy measures that are likely to guarantee certain electric vehicle uptake rates over the next decade. Lastly, the effect of replacing one conventional vehicle by one electric vehicle on the public budget is investigated. Both, vehicle manufacture and use aspects are considered. The set up valuation model hereby accounts for direct and indirect financial impacts on the public budget. These comprise direct purchase subsidies, tax breaks, and tax income, as well as effects of changing employment situations that alter the amount of social contributions and unemployment benefits. The study's findings and considerations allow for various suggestions for vehicle manufacturers and policy makers willing to support the uptake of electric vehicles. These are listed in the conclusions section which also sketches directions for further research.

Contributions to the environmental assessment of road transport

Scipedia content — Tue, 26 Jan 2021 17:41:27 +0100

El objetivo de esta tesis es proporcionar un mayor grado de conocimiento sobre ciertos aspectos medioambientales del transporte por carretera que aún no han sido investigados en profundidad. En concreto, la tesis aborda las siguientes líneas de investigación: análisis del ciclo de vida (ACV) de los pavimentos de carreteras, ACV del ruido del transporte por carretera, y valoración de los costes externos del ruido del transporte por carretera. "p"La evaluación ambiental del transporte rodado se ha centrado fundamentalmente en los impactos ambientales de las emisiones atmosféricas de los vehículos que circulan por las carreteras, mientras que los impactos de la construcción, mantenimiento y fin de vida de las carreteras no han recibido demasiada atención. La metodología del ACV puede ser útil para abordar esta limitación, ya que tiene como objetivo evaluar los impactos ambientales asociados a todas las etapas del ciclo de vida de un producto o servicio desde la cuna hasta la tumba. En esta tesis se ha realizado un ACV exhaustivo de pavimentos de carreteras, y se ha desarrollado una herramienta de ACV para calcular de forma automática los impactos ambientales de los pavimentos. Se han analizado distintos tipos de pavimentos, incluyendo mezclas bituminosas en caliente (MBC, fabricadas a 165 °C), mezclas bituminosas templadas (MBT, fabricadas a 135 °C) mediante la adición de zeolitas sintéticas, y mezclas bituminosas con pavimento asfáltico reciclado (PAR). De este modo, se han evaluado los impactos ambientales asociados al consumo de energía y a las emisiones atmosféricas, así como otros impactos ambientales debidos a la extracción y procesado de minerales, betunes y aditivos químicos; fabricación de asfaltos; transporte de materiales; pavimentación; tráfico durante la vida útil del pavimento; transformación y ocupación del suelo; desmantelamiento del pavimento al final de su vida útil y su reciclaje o eliminación en vertedero. También se han realizado simulaciones mediante el método de Monte Carlo para tener en cuenta la variabilidad de ciertos parámetros de entrada críticos. Al considerar todo el ciclo de vida, se ha observado que los impactos de los pavimentos de MBT a base de zeolita son casi idénticos a los impactos de los pavimentos de MBC con el mismo contenido de PAR. La reducción de los impactos que se obtiene en las MBT al disminuir la temperatura de fabricación queda contrarrestada por los mayores impactos de los materiales utilizados, sobre todo los impactos de las zeolitas sintéticas. Por otro lado, al comparar mezclas bituminosas con distintos contenidos de PAR, se ha observado que los impactos de las mezclas se reducen de forma significativa al añadir PAR. Todos los impactos en las categorías "de punto final", así como los impactos en las categorías de cambio climático, agotamiento de recursos fósiles y demanda de energía acumulada, se han reducido un 13-14% mediante la adición de un 15% de PAR. Una ventaja clave de las MBT es el uso potencialmente mayor de PAR. Por lo tanto, la reducción de los impactos que se consigue añadiendo grandes cantidades de PAR a las MBT podría convertirlas en una buena alternativa a las MBC desde el punto de vista medioambiental. "p"A diferencia de otros contaminantes del transporte rodado (por ejemplo, las emisiones gaseosas), el ruido rara vez se incluye en los estudios de ACV, debido a que tiene ciertas particularidades (dependencia de factores locales, imposibilidad de agregar linealmente sus emisiones, etc.) que dificultan la evaluación de su impacto. La escasez de datos sobre ruido ha supuesto un inconveniente añadido para evaluar su impacto. Sin embargo, la publicación reciente de los mapas estratégicos de ruido ofrece la oportunidad de superar estas limitaciones. En esta tesis se ha desarrollado un método para evaluar el impacto del ruido del transporte rodado e integrarlo en el marco del ACV. Este método resuelve las limitaciones metodológicas observadas en otros trabajos previos y permite realizar las evaluaciones a partir de datos de los mapas estratégicos de ruido. Los impactos del ruido sobre la salud se cuantifican en DALYs (años de vida ajustados por discapacidad), posibilitando la comparación y agregación del ruido con otros contaminantes nocivos para la salud. La tesis también incluye un caso de estudio donde el método propuesto se ha aplicado para calcular el impacto del ruido causado por un vehículo pesado adicional en tres carreteras distintas. El impacto del ruido causado por el vehículo pesado varía considerablemente de una carretera a otra (hasta el punto de doblarse), debido a la dependencia del impacto del ruido de factores locales, como las condiciones de tráfico y la densidad de población cercana a las carreteras. La extrapolación de los resultados obtenidos para una carretera determinada a otras carreteras puede, por lo tanto, conducir a estimaciones erróneas de los impactos del ruido, siendo difícil predecir el error incurrido. Por esta razón, se recomienda realizar evaluaciones específicas del impacto del ruido para cada caso particular, siempre que haya datos de tráfico y de exposición al ruido. El método propuesto permite realizar tales evaluaciones de forma sencilla y eficaz a partir de datos públicos disponibles en los mapas estratégicos de ruido. Además, el impacto del ruido causado por el vehículo pesado se ha comparado y agregado con los impactos sobre la salud debidos al consumo de combustible y a las emisiones atmosféricas de ese mismo vehículo. El impacto del ruido ha supuesto entre el 2,58% y el 4,96% del impacto total causado por el vehículo pesado adicional. El ruido ha resultado ser la tercera categoría de impacto más significativa en términos de daños a la salud, únicamente superado por el cambio climático y por la formación de partículas. Por lo tanto, el ruido del transporte rodado puede tener un impacto significativo comparado con otras categorías de impacto evaluadas normalmente en el ACV, lo que justifica su inclusión como categoría de impacto habitual en los estudios de ACV del transporte rodado. Una solución eficaz para reducir los impactos ambientales del transporte rodado es internalizar los costes externos de tales impactos mediante instrumentos de tarificación; por ejemplo, tasas a los usuarios de las carreteras según la contaminación que producen. Estas tasas pueden alentar a los usuarios a utilizar tecnologías del automóvil más limpias y a optimizar sus comportamientos logísticos, mientras que los ingresos de las tasas pueden destinarse a reducir la contaminación en su origen y a fomentar la movilidad sostenible. La Directiva Euroviñeta permite a los Estados miembros de la UE aplicar tasas a los vehículos pesados con el fin de compensar los costes de la contaminación acústica que originan. Para ello, proporciona un método para el cálculo de los costes externos del ruido del tráfico rodado. Este método requiere el uso de factores de ponderación para cada categoría de vehículo y para cada período del día con vistas a permitir la diferenciación de los costes del ruido, sin embargo, la Directiva Euroviñeta no proporciona valores específicos o directrices para el cálculo de tales factores. Por esta razón, en esta tesis se ha desarrollado un método alternativo para calcular los costes externos del ruido del tráfico rodado en Europa. Asimismo, se han desarrollado factores de ponderación mejorados que constituyen la base del método propuesto. Estos factores son más fiables que los que se aportan en otros estudios, ya que están altamente diferenciados para reflejar de forma precisa la influencia de los factores clave, como la categoría de vehículo, la velocidad y el período del día. El método propuesto permite obtener tasas basadas en la distancia para cualquier categoría de vehículo (turismos, furgonetas, vehículos pesados, ciclomotores y motocicletas) y período del día (día, tarde y noche), mientras que el método de la Directiva Euroviñeta solo es aplicable a los vehículos pesados en los períodos diurno y nocturno. La tesis también incluye un caso de estudio donde el método propuesto se ha aplicado para calcular los costes medios del ruido por vehículo-kilómetro según la categoría de vehículo y el período del día para tres carreteras distintas. Los costes del ruido difieren considerablemente de una carretera a otra (hasta el punto de casi triplicarse), debido a la dependencia de los costes del ruido de factores locales. Si se hubiera aplicado un enfoque "top-down", como establece la Directiva Euroviñeta, los costes del ruido habrían sido iguales en todas las carreteras, lo cual no es coherente con el principio de "quien contamina paga", que debe regir la tarificación por el uso de la infraestructura vial. Por otro lado, se ha comprobado que la falta de diferenciación en base a la velocidad, que presentan los factores de ponderación aportados en otros estudios previos, puede llevar a errores significativos de los costes del ruido atribuibles a los vehículos de las distintas categorías. Si en el caso de estudio se hubieran aplicado los factores de ponderación de otro estudio, el error cometido habría variado entre -37,36% y -24,27% para los turismos y entre 30,24% y 57,46% para los vehículos pesados, dependiendo de la carretera. Por lo tanto, las tasas aplicadas a los vehículos pesados se habrían sobrestimado considerablemente, lo cual también es incoherente con el principio de quien contamina paga.

Transit-Oriented Development in China

Scipedia content — Tue, 26 Jan 2021 17:37:39 +0100

Electric vehicles recharge scheduling with time windows

Scipedia content — Tue, 26 Jan 2021 17:33:36 +0100

von Damir Bučar Zsfassung in dt. Sprache Wien, Techn. Univ., Dipl.-Arb., 2014

T-Sofia : Tunnelbanestation i Stockholm

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

Under hösten 2013 offentliggjorde den svenska regeringen att man vill investera i att bygga ut Stockholms tunnelbana. Denna utbyggnad innefattar nio nya stationer, Sofia på Södermalm är en av dessa stationer. På grund av platsens förutsättningar kommer stationen bli en av de djupaste i världen. Detta förslag utnyttjar dessa förutsättningar för att sammankoppla gatunivån med den underjordiska perrongen och ger den vardagliga upplevelsen av rymd, atmosfär, ljus och tomrum en central position. Förslaget innefattar ett hundra meter djupt schakt, två hisschakt, ett publikt torg park och tunnelbaneperrong. During the autumn of 2013 the Swedish government announced that they intend to invest in expanding the Stockholm Metro. The expansion includes nine new stations; Sofia on Södermalm is one of them. The conditions of the site make the station to one of the deepest in the world. This proposal makes use of these conditions to connect the street level and the underground platform level and give the everyday experience of space, atmosphere, light and void a central position. The proposal comprises a hundred meters deep shaft, two elevator shafts, a public square park and train platform.

The power of independence : increasing energy self-sufficiency on a small island state

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

Fossil fuels constitute 21% of import costs and are the basis for 76% of electricity generation on Mauritius. The volatility and unpredictability in fossil fuel prices and supply are incentives to reduce dependency on these fuels. This thesis explores the possibilities for the main island of Mauritius to reduce future fossil fuel dependency, with a focus on the electricity sector. A field trip to the island was conducted in August 2012, to collect data and broaden the understanding of challenges and opportunities in the Mauritian energy system. The implications of implementing solar panels, electric vehicles and gas power plants as alternatives to a planned 100 MW coal power plant are studied. In this scenario, the balance between the need for peak and base capacity is considered. It is shown how solar panels can meet daytime peak demand, while utilizing storage capacity of electric vehicle batteries to meet evening peak demand. Natural gas generators provide backup capacity and flexibility for cloudy days and evening demand. The solutions are scalable, and could be deployed separately or as a combination. Together, they could replace the coal power plant and thereby reducing the expected growth in fossil fuel imports by 28%. Implemented on a larger scale, they could also reduce overall fossil fuel imports. Solutions like this will also be relevant for other small island states and even for larger states as they try to convert their own energy systems towards one based on renewable energy. Norad/Many Strong Voices, Tekn

PCE prototype with segment routing and BGPLS support

Scipedia content — Tue, 26 Jan 2021 17:09:02 +0100

This project presents two contributions to the PCE implementation in Telefonica I+D: Segment Routing and the upgrade of the BGP-LS protocol to the 3rd version of the draft to support MPLS and GMPLS scenarios. Regarding the first contribution, this document is intended to assess the use of Segment Routing in centralised traffic-engineering scenarios. It will attempt to make a validation of such technology using the available IETF drafts and publications and trying, at all time, to back-up the use cases with experimental demonstrations. Moreover, the 3rd version of the BGP-LS protocol draft was implemented. This protocol opens the possibility to export the network’s topology and its Traffic Engineering parameters to external entities. The BGP-LS extensions developed enables to retrieve the TE parameters for MPLS and GMPLS networks. The development of the project was done in Telefonica R&D’s facilities within the Core Network Evolution group. The code extends Telefonica’s PCE and network protocols to support Segment Routing and the new version for BGP-LS. As such, both the PCEP and the BGP-LS protocols were enhanced with the latest IETF drafts that define the technology. Once the code was developed and debugged, a series of tests were run in order to validate that the format used followed all the proposed standards. These tests have been defined following the sections that constitute each draft in an attempt to proof the use of each protocol in the most exhaustive possible way. It is important to remark that the validation tests are done not only with Telefonica code, but also with external prestigious entities like Cisco, Telecom Italia, Centre Tecnològic Telecomunicacions Catalunya or Consorzio Nazionale Interuniversitario per le Telecomunicazioni. Ingeniería de Telecomunicación

Ground borne vibrations from high speed trains

Scipedia content — Tue, 26 Jan 2021 17:07:21 +0100

consequence of high speed rail transportation is the generation of elevated ground borne vibrations. This thesis presents several original contributions towards the prediction of these vibrations. Firstly, a new three dimensional finite element model capable of vibration prediction was developed. Its main feature was its ability to model complex track geometries while doing so through a fully coupled vehicle-tracksoil system. Model output was compared to experimental results obtained during this thesis and also to independent data sets. It was shown to predict velocity time histories, vibration frequency spectrums and international vibration descriptors with high accuracy. An appraisal of the suitability of a finite difference time domain modelling approach for railway vibration prediction was also undertaken. This resulted in the development of a new ‘higher order’ perfectly matched layers absorbing boundary condition. This condition was found to offer higher performance in comparison to current alternative absorbing boundary conditions. Field work was then undertaken on high speed lines with varying embankment conditions in Belgium and England. Vibration data was recorded up to 100m from each track and geophysical investigations were performed to determine the underlying soil properties. The results were used for numerical model validation and also to provide new insights into the effect of various embankment conditions on vibration propagation. It was found that embankments generate higher frequency excitation in comparison to nonembankment cases and that cuttings generate higher vibration levels than noncuttings. Once validated the finite element model was used to provide new insights into the effect of train speed, embankment constituent materials and railway track type on vibration levels. It was found that the shape and magnitude of ground vibration increased rapidly as the train’s speed approached the Rayleigh wave speed of the underlying soil. It was also found that ballast, slab and metal tracks produced similar levels of vibration and that stiffer embankments reduced vibration levels at distances near and far from the track. Two vibration mitigation techniques were also explored through numerical simulation. Firstly, an analysis was undertaken to determine the ability of a new modified ballast material to actively isolate vibration within the track structure. Secondly, wave barrier geometries were investigated to optimise their performance whilst minimising cost. It was found that barrier depth was the most influential parameter, whereas width had little effect. Additionally, geometry optimisation was found to result in a 95% cost saving in comparison to a base case. Using a vast array of results generated using the previously developed finite element model, a new empirical prediction model was also developed, capable of quickly assessing vibration levels across large sections of track. Unlike currently available empirical models, it was able to account for soil properties in its calculation and could predict a variety of international vibration metrics. It was shown to offer increased prediction performance in comparison to an alternative empirical model.

Análise de consumo de combustível em veículo automotor hibridizado

Scipedia content — Tue, 26 Jan 2021 17:02:39 +0100

Orientador: Franco Giuseppe Dedini Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica Made available in DSpace on 2018-08-26T13:12:33Z (GMT). No. of bitstreams: 1 Costa_EduardodosSantos_M.pdf: 3795975 bytes, checksum: 57e8b74b69e23ca6a180dd32323f0a1e (MD5) Previous issue date: 2014 Resumo: Veículos Elétricos Híbridos representam, atualmente, uma alternativa para a redução do consumo de combustível fóssil utilizado pelos motores de combustão interna. Este trabalho analisa, em uma plataforma de simulação computacional e em condição experimental, o consumo de combustível de um veículo automotor, antes e após a hibridização. As simulações computacionais auxiliam, através de modelos matemáticos, um maior entendimento dos fenômenos físicos relacionados com os problemas de engenharia. Um modelo computacional bem elaborado possui um elevado grau de fidelidade em relação aos sistemas reais, tornando-se assim uma poderosa ferramenta de análise. A realização de experimentos, além de permitir uma comprovação de resultados, contribui para um refinamento dos modelos simulados. A tecnologia híbrida em estudo caracteriza-se pelo acoplamento de dois motores elétricos diretamente nas rodas traseiras do veículo. Por fim, busca-se a verificação da similaridade de comportamentos e/ou investigação de possíveis divergências entre o modelo matemático desenvolvido e os experimentos realizados. Um modelo de dinâmica veicular longitudinal descrito pela literatura é implementado no software Matlab/SimulinkTM e os resultados são comparados com os experimentos realizados em um dinamômetro de chassi Abstract: Hybrid Electric Vehicles currently represent an alternative to reducing fossil fuel consumption used by internal combustion engines. This paper analyses, in a platform of computational simulation and also in experimental condition, the vehicle fuel consumption, before and after hybridization. It checks the similarity of behaviors and/or the investigation of possible differences between the developed mathematical model and experiments performed. Computer simulations help, through mathematical models, a better understanding of physical phenomena related to engineering problems. A well elaborated computer model has a high fidelity degree with the real systems, becoming a powerful analysis tool. The experiments besides allowing a proof of results, they contribute to a refinement of the simulated models. The hybrid technology under study is characterized by the coupling of two electric motors directly to the rear vehicle wheels. A model for the vehicle longitudinal dynamics described in the literature is implemented in Matlab/SimulinkTM software and the results are compared with the experiments performed on a chassis dynamometer Mestrado Mecanica dos Sólidos e Projeto Mecanico Mestre em Engenharia Mecânic

The challenge of designing intelligent support behavior

Scipedia content — Tue, 26 Jan 2021 16:53:29 +0100

In the present thesis, advanced driver assistance systems are viewed as instances of cognitive support systems when the driving task is shared between driver and assistance systems that monitor and infer driver’s behavior, complement the driver with information and warnings or even co-control the vehicle. It is suggested to support the design and research process of such systems with humans simulating the support behavior (emulation, cf. Wizard of Oz technique). Accordingly, the potential of emulation as a simulation alternative and research tool was validated and explored experimentally. On the one hand, emulation enables short, premature and flexible design iterations, including the ability to explore design solutions without the need for a fully functioning prototype (e.g. bypassing the difficulty or inability to automate perceptual abilities). On the other hand, it suggests an approach where humans observing or assisting other humans become the subject at hand, i.e. the innate human ability to monitor and infer other’s needs and intentions might provide valuable information about the cues and strategies that are used in human-human cooperation. Such insights might have the potential to contribute to the development of new technologies, both in terms of sensing human behavior in a variety of situations and in terms of providing relevant information or support (in various modalities).

Reconnaissance automatique de cibles par utilisation de signaux de radars passifs bistatiques

Scipedia content — Tue, 26 Jan 2021 16:53:06 +0100

We present the design, development, and test of three novel, distinct automatic target recognition (ATR) systems for the recognition of airplanes and, more specifically, non-cooperative airplanes, i.e. airplanes that do not provide information when interrogated, in the framework of passive bistatic radar systems. Passive bistatic radar systems use one or more illuminators of opportunity (already present in the field), with frequencies up to 1 GHz for the transmitter part of the systems considered here, and one or more receivers, deployed by the persons managing the system, and not co-located with the transmitters. The sole source of information are the signal scattered on the airplane and the direct-path signal that are collected by the receiver, some basic knowledge about the transmitter, and the geometrical bistatic radar configuration. The three distinct ATR systems that we built respectively use the radar images, the bistatic complex radar cross-section (BS-RCS), and the bistatic radar cross-section (BS-RCS) of the targets. We use data acquired either on scale models of airplanes placed in an anechoic, electromagnetic chamber or on real-size airplanes using a bistatic testbed consisting of a VOR transmitter and a software-defined radio (SDR) receiver, located near Orly airport, France. We describe the radar phenomenology pertinent for the problem at hand, as well as the mathematical underpinnings of the derivation of the bistatic RCS values and of the construction of the radar images.For the classification of the observed targets into pre-defined classes, we use either extremely randomized trees or subspace methods. A key feature of our approach is that we break the recognition problem into a set of sub-problems by decomposing the parameter space, which consists of the frequency, the polarization, the aspect angle, and the bistatic angle, into regions. We build one recognizer for each region. We first validate the extra-trees method on the radar images of the MSTAR dataset, featuring ground vehicles. We then test the method on the images of the airplanes constructed from data acquired in the anechoic chamber, achieving a probability of correct recognition up to 0.99.We test the subspace methods on the BS-CRCS and on the BS-RCS of the airplanes extracted from the data acquired in the anechoic chamber, achieving a probability of correct recognition up to 0.98, with variations according to the frequency band, the polarization, the sector of aspect angle, the sector of bistatic angle, and the number of (Tx,Rx) pairs used. The ATR system deployed in the field gives a probability of correct recognition of $0.82$, with variations according to the sector of aspect angle and the sector of bistatic angle.; Dans cette thèse, nous présentons la conception, le développement et le test de trois systèmes de reconnaissance automatique de cibles (ATR) visant à reconnaître des avions non-coopératifs, c’est-à-dire des avions ne fournissant par leur identité, en utilisant des signaux de radars passifs bistatiques. Les radars passifs bistatiques utilisent un ou plusieurs émetteurs d’opportunité (déjà présents sur le terrain), avec des fréquences allant jusqu’à 1 GHz pour les émetteurs considérés ici, et un ou plusieurs récepteurs déployés par le gestionnaire du système et non-colocalisés avec les émetteurs. Les seules informations utilisées sont les signaux réfléchis sur les avions et les signaux directement reçus qui sont tous les deux collectés par le récepteur, quelques informations concernant l’émetteur, et la configuration géométrique du radar bistatique.Les trois systèmes ATR que nous avons construits utilisent respectivement les images radar, les surfaces équivalentes radar (SER) complexes bistatiques et les SER réelles bistatiques. Nous utilisons des données acquises soit sur des modèles d’avions placés en chambre anéchoique à l’ONERA, soit sur des avions réels en utilisant un banc d’essai bistatique consistant en un émetteur VOR et un récepteur basé sur la radio-logicielle (SDR), et que nous avons déployé aux alentours de l’aéroport d’Orly. Nous décrivons d’abord la phénoménologie radar pertinente pour notre problème ainsi que les fondements mathématiques pour la dérivation de la SER bistatique d’un objet, et pour la construction d’images radar d’un objet.Nous utilisons deux méthodes pour la classification de cibles en classes prédéfinies : les arbres extrêmement aléatoires (extra-trees) et les méthodes de sous-espaces. Une caractéristique-clé de notre approche est que nous divisons le problème de reconnaissance global en un ensemble de sous-problèmes par décomposition de l’espace des paramètres (fréquence, polarisation, angle d’aspect et angle bistatique) en régions. Nous construisons un classificateur par région.Nous validons en premier lieu la méthode des extra-trees sur la base de données MSTAR, composée d’images radar de véhicules terrestres. Ensuite, nous testons cette méthode sur des images radar d’avions que nous avons construites à partir des données acquises en chambre anéchoique. Nous obtenons un pourcentage de classification allant jusqu’à 99%. Nous testons ensuite la méthode de sous-espaces sur les SER bistatiques (complexes et réelles) des avions que nous avons extraits des données de chambre anéchoique. Nous obtenons un pourcentage de classification allant jusqu’à 98%, avec des variations suivant la fréquence, la polarisation, l’angle d’aspect, l’angle bistatique et le nombre de paires émetteur-récepteur utilisées. Nous testons enfin la méthode de sous-espaces sur les SER bistatiques (réelles) extraites des signaux acquis par le banc d’essai déployé à Orly. Nous obtenons une probabilité de classification de 82%, avec des variations suivant l’angle d’aspect et l’angle bistatique. On a donc démontré dans cette thèse que l’on peut reconnaitre des cibles aériennes à partir de leur SER acquise en utilisant des signaux de radars passifs bistatiques.

Performance study of a passive radiation detector for aviation purpose using the Monte carlo method

Scipedia content — Tue, 26 Jan 2021 16:51:27 +0100

Profissionais da área aeronáutica, como pilotos e comissários de bordo, são submetidos a doses de radiação de origem cósmica, que podem ser maiores do que as doses médias dos trabalhadores da indústria nuclear. A diversidade de partículas de altas energias presentes no campo de radiação a bordo das aeronaves torna complexa a mensuração da dose e requer cuidados especiais em relação aos sistemas de dosimetria a serem empregados nesta área. A Força Aérea Brasileira, por meio de seu Instituto de Estudos Avançados (IEAv /DCTA), em conjunto com o Instituto de Pesquisas Energéticas e Nucleares (IPEN / CNEN -SP) vem estudando o assunto desde 2008. Um protótipo de detector de radiação passivo para medições em aeronaves foi previamente construído e testado em condições de voo e de laboratório. O detector é capaz de medir a grandeza dosimétrica conhecida como dose absorvida (usando dosímetros passivos), que serão posteriormente correlacionados ao equivalente de dose ambiente e à dose efetiva recebidos por profissionais da área aeronáutica. Neste contexto, uma abordagem teórica por meio de simulações Monte Carlo com os códigos computacionais MCNP5 e MCNPX, foi usada para modelar e caracterizar a resposta do detector em determinadas condições experimentais. Este trabalho apresenta os resultados preliminares da modelagem computacional, com ênfase especial na comparação entre a grandeza fundamental dose absorvida (mensurada e simulada) e sua relação com o equivalente de dose ambiente e dose efetiva para este detector. Aircrews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of aircrafts, turns the determination of the incident dose and requires special care regarding dosimetric systems to be used in this kind of field. The Brazilian Air Force, through the Institute for Advanced Studies (Instituto de Estudos Avançados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energéticas e Nucleares IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by aircrews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed dose quantity (measured and simulated) and its relationship with the ambient dose equivalent and the effective Dose for this detector.

Modelo de elección de modo de transporte entre carretera y ferrocarril para carga general susceptible a exportación-importación. Aplicación al corredor vial Medellín – puerto de Cartagena.

Scipedia content — Tue, 26 Jan 2021 16:41:57 +0100

Resumen: La investigación desarrollada en esta tesis de maestría presenta una aplicación de la técnica de preferencias declaradas, para la construcción de un modelo de elección de modo de transporte entre carretera y ferrocarril para carga general susceptible a exportación-importación, aplicado a las empresas antioqueñas. Aunque el transporte de carga por carretera presenta muchos inconvenientes en el país, no existe un estudio que demuestre cuáles son las variables que influyen en la elección de un modo de transporte de carga en Antioquia, para saber si realmente sería útil un ferrocarril para la región. La investigación cualitativa se presenta en este estudio a través de las técnicas de grupo focal con las empresas importantes de la región, de esta manera se logran conocer las variables que influyen en la elección de un modo de transporte por parte de las empresas antioqueñas que exportan-importan mercancías, las cuales resultaron ser costo de la tonelada/km y frecuencia de servicio por semana. Uno de los aportes más importantes de este trabajo es calibrar un modelo de elección discreta con las variables identificadas que inciden en la elección de modo de transporte para movilizar carga por parte de las empresas antioqueñas, y estimar la influencia que tiene cada una de estas variables. Los resultados muestran que la probabilidad de captación en carga general del modo ferrocarril varía entre el 67.00% y el 92.66% cuando se compara con la carretera, en los tomadores de decisión de las empresas antioqueñas, según sea la variación de las variables influyentes en la elección de un modo de transporte (costo y frecuencia de servicio) desmintiendo la importancia de la variable tiempo de viaje, la cual por los tiempos muertos del cargue-descargue y espera en los puertos no es decisiva al comparar los dos modos. Otro aporte importante de esta investigación es el planteamiento de un trazado preliminar de un sistema férreo entre Medellín y Cartagena, el cual puede servir como base para realizar otros estudios de prefactibilidad para extraer costos y tiempos de este proyecto. Abstract: The developed research in this M.Sc. thesis, presents a technical application of stated preferences, for the construction of a choice modeling of a transportation mode between road and rail for general freight susceptible to exportation-importation, applied to the Antioquian companies. Although freight transportation by road has too many inconveniences in the country, doesn’t exist a study that shows what are the variables that influence the choice of transport mode in Antioquia, to know if really would be important a railroad for the region. Qualitative research presented in this study through focus group techniques with important companies of the region, so this way it's possible to know the variables that influence the choice of transportation mode by the companies of Antioquia that export-import merchandise, resulting cost and frequency the most important. One of the most important contributions in this job is to calibrate a discrete choice model with identified variables that identify the influence in the choice of a transportation mode to mobilize freight by the Antioquian companies, and estimate the influence that has each one of these variables. The results show that that the probability of the decision makers of the Antioquian companies choosing the railway mode varies between 67.00 % and 92.66 % when comparing with highway mode, to move general freight, and this depends on the variation of the influencing variables in the choice of a transportation mode (cost and service frequency), denying the importance of the variable travel time, which is not decisive to compare the two modes because the idle time at origin and ports. Another contribution in the present research is the approach of a preliminary layout of a rail system between Medellin and Cartagena, which can serve as a basis for other studies of feasibility to extract costs and times of this project.

Towards Collaborative Internet Content Delivery

Scipedia content — Tue, 26 Jan 2021 16:33:05 +0100

Der heutige Internetverkehr wird von Content Distribution Infrastructures (CDI), z.B. Content Distribution Networks, Hyper-Giants und One-Click-Hostern, dominiert. Um das rasante Wachstum der Daten zu bewältigen, betreiben CDIs massive Infrastrukturen. Aber mit deren Größe wachsen auch die operativen Herausforderungen. Hier erweist es sich als schwierig, die Server-zu-User Zuweisung aktuell zu halten, da dem CDI die Netzwerktopologie, deren aktueller Zustand und die genaue Netzwerkposition des Users nicht bekannt sind. Zur gleichen Zeit sehen sich Netzwerkbetreiber, genannt Internet Service Provider (ISP), mit dem stark wachsenden und immer unberechenbarer werdenden Verkehrsverhalten der CDIs ausgesetzt, ohne darauf entsprechend reagieren zu können. Diese Schwierigkeiten zwischen ISPs und CDIs resultieren aus dem fehlenden Mechanismus der ISPs ihr Netzwerkwissen an die CDIs zu kommunizieren. Um das Server-zu-User Zuweisungsproblem zu lösen, beschäftigen wir uns zuerst mit IP-Geolocation. Hier legen wir den Fokus auf zwei Ansätze: a) das Auswerten von GPS Koordinaten, die von Usern selbst bereitgestellt werden und b) eine generelle Studie von IP-Geolocation Datenbanken. In beiden Fällen wird deutlich, dass IP- Geolocation nur sehr begrenzt helfen kann. Besonders in mobilen Datennetzen ist IP-Geolocation keine Hilfe. Als nächstes wenden wir uns dem Problem der Netzwerk- und Topologieunkenntnis von CDIs zu. Unsere Lösung dieses Problems beruht auf Kooperation zwischen CDIs und ISPs. Hierzu beschreiben, entwickeln und implementieren wir das Provider-aided Distance Information System (PaDIS), welches von ISPs betrieben wird und es CDIs ermöglicht, aktuelle Netzwerkinformationen zu beziehen. Dazu benutzt PaDIS Information aus dem operativen Betrieb einer ISP um CDIs den besten Server, basierend auf verschiedenen Metriken, wie Auslastung, Hops oder Latenz, vorzuschlagen. Außerdem wird durch PaDIS auch das Server-zu-User Zuweisungsproblem gelöst, was mit IP-Geolocation nicht möglich war. Unsere Auswertung zeigt dabei, dass PaDIS die Zeiten zum Herunterladen von Dateien um einen Faktor von Vier verkürzen kann. Davon profitieren nicht nur CDIs, sondern auch die User. ISPs ziehen aus dem Einsatz von PaDIS den Vorteil, dass sie die Zuweisung von Server-zu-User mitsteuern können. Wir entwerfen das Konzept des Content-aware Traffic Engineering (CaTE), welches den Verkehr von CDIs dynamisch an die aktuelle Last von Netzwerken anpasst. Im Ergebnis wird die Zuordnung von Server-zu-User deutlich verbessert, was sich sowohl positiv für das CDI als auch die User auswirkt. Weiterhin erlangen ISP die Fähigkeit, Datenströme auf Netzwerkpfade mit wenig Belastung zu legen. Unsere Auswertung von CaTE, welche auf operativen Daten einer ISP beruht, zeigt, dass sowohl die Pfadlängen als auch die Latenz zwischen Server und User signifikant verringert werden, während die ISPs ihren Datenverkehr gleichmäßiger verteilen können und dadurch die Gesamtlast des Netzwerks senken. Today, a large fraction of Internet traffic is originated by Content Distribution Infrastructures (CDIs), such as content distribution networks, hyper-giants and One-Click-Hosters. To cope with the increasing demand for content, CDIs deploy massive centralized or distributed infrastructures. For CDIs, the operation of their infrastructures is challenging, as they have to dynamically map end-users to appropriate servers without being fully aware of the end-users’ network locations. Apart from CDIs, the operational overhead of Internet Service Providers (ISPs) is growing increasingly complex, due to content delivery traffic caused by CDIs. In fact, the difficulties ISPs have with regards to engineering their traffic, stem from the fact that CDIs have limited knowledge about network conditions and infrastructures, while ISPs cannot communicate their insight about networks to CDIs. To solve the mapping challenges CDIs face, we studying the applicability of IP-Geolocation to optimize CDI operation in terms of end-user to server mapping. We base the study on two different approaches: a) an evaluation of end-user submitted GPS coordinates and b) a general study of IP-Geolocation databases. We find that in both cases, IP-Geolocation is only of limited help to select servers close to end-users. Especially in mobile environments, we find that IP-Geolocation is unable to solve the mapping problem. We broaden the scope and tackle CDIs’ general lack of awareness with regards to ISP networks. We argue that the challenges CDIs and ISPs face today can be turned into an opportunity when enabling collaboration between the two. We propose, design and implement a solution, where an ISP offers a Provider-aided Distance Information System (PaDIS) as an interface for CDIs. PaDIS uses information available only to the ISP to rank any client-host pair, based on up-to-date network information, such as delay, bandwidth or number of hops. By extension, this approach also implicitly solves the mapping problem IP-Geolocation was unable to resolve. Experiments with different CDIs show that improvements in download times of up to a factor of four are possible. Furthermore, we show that deploying PaDIS not only benefits CDIs, but also end-users. With regards to the benefits for ISPs, we show that by offering PaDIS to CDIs, ISPs are able to partly reclaim control of the traffic induced by CDIs. We design the concept of Content-aware Traffic Engineering (CaTE), which dynamically adapts the traffic demand for content hosted on CDIs by utilizing PaDIS during their server selection process. As a result, CDIs enhance their end-user to server mapping and improve end-user experience. In addition, ISPs gain the ability to partially influence traffic demands within their networks. Our evaluation, based upon operational data from a large tier-1 ISP, shows improvements minimizing the path length as well as delay between end-user and assigned CDI server, significant reduction in network-wide traffic and in maximum link utilization.

German electric vehicle charging infrastructure: statistically based approach to derive the demand and geographical distribution of charging points

Scipedia content — Tue, 26 Jan 2021 16:19:07 +0100

The forthcoming EU-limitations on sulphur emissions and the growing usage of 45 foot containers: Challenges and chances for short sea shipping in the Baltic Sea Region

Scipedia content — Tue, 26 Jan 2021 16:07:26 +0100

Dose control in road transport of radioactive material

Scipedia content — Tue, 26 Jan 2021 16:06:12 +0100

doses de radiação ionizante para os trabalhadores no transporte de material radioativo devem ser tão pequenas quanto razoavelmente exequível. As doses médias dos motoristas e carregadores amostrados neste trabalho devem ser diminuídas. A demonstração do controle das doses em veículo rodoviário com material radioativo, requisitada pelo regulamento brasileiro atual, norma CNEN NE 5.01, é apresentada em formulário próprio com valores de exposição obtidos em posições de ocupação regular de indivíduos do público e de trabalhadores, mesmo quando se expede veículo sem a necessidade de uso exclusivo (∑ IT 50). Este trabalho mostra, por meio de pesquisa bibliográfica, elaboração de modelos e pesquisa de campo, que esta demonstração do controle com a obtenção dos valores de exposição nesta situação, para um método de controle melhor, deve ser realizada pela apresentação do registro do acúmulo de cargas, limitado (∑ IT 50), a fim de evitar a obtenção destas medidas, para que haja padronização com regulamentos estrangeiros e para que os custos e os tempos, importantes para expedição de radiofármacos com meia-vida curta, e também as atuais doses laborais dos técnicos de radioproteção sejam todos diminuídos. Os valores de exposição dos parâmetros utilizados com esse método são menores do que seus limites regulamentares. Para contribuir com essas finalidades devem ser apresentadas pelo regulamento brasileiro atualizado as distâncias de segregação entre as cargas e as cabines dos veículos. The radiation doses to workers in the transport of radioactive material should be as low as reasonably achievable. The average doses of drivers and loaders, sampled in this thesis should be decreased. The demonstration of doses control in a road vehicle with radioactive material required by the current Brazilian regulation, CNEN NE 5.01 should be written in its own printed form with exposure values obtained in normally occupied positions from workers and members of the public, even when the consignment does not need \\"exclusive use\\" (∑ IT 50). Through bibliographic research, modeling and field research, this research work shows that this demonstration of the control should be done by writing the registration accumulation of load, limited (∑ IT 50), also in the own printed form. It is for a better control method, in order to avoid the use of measuring equipment, to build standardization with foreign regulations, to the current occupational doses of radioprotection technicians, the costs and time, (important for consignment with radiopharmaceuticals short half-life) would be all smaller. Exposure values of the parameters used with this method are smaller than regulatory limits. The segregation distances between loads and the cabins of vehicles shall be showed by Brazilian regulation updated to contribute to these aims.

Avaliação de desempenho do sistema BRT da cidade de Lima utilizando o auxílio multicritério à decisão

Scipedia content — Tue, 26 Jan 2021 16:03:13 +0100

Orientador: Maria Lucia Galves Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo Made available in DSpace on 2018-08-25T22:44:56Z (GMT). No. of bitstreams: 1 EnriquezBilbao_NidiaMarisol_M.pdf: 3451162 bytes, checksum: 9e30dc21d024803c6ac586a0de3a283e (MD5) Previous issue date: 2014 Resumo: As cidades necessitam de sistemas de transporte eficientes, tanto para a movimentação de bens quanto de pessoas e para a realização das atividades fundamentais. O transporte caracteriza-se, portanto, como uma das atividades principais para o atendimento das necessidades de crescimento dos centros urbanos. Uma das opções adotadas para o transporte público urbano é o sistema BRT (Bus Rapid Transit), que consegue atender a necessidades de transporte com baixo custo de implantação, provocando impactos positivos em sua área de influência. Diante disso, sistemas BRT foram implantados em muitas cidades no mundo, o que torna a avaliação de desempenho deste modo de transporte uma necessidade atual e de grande importância para o desenvolvimento adequado dos centros urbanos. O objetivo do presente trabalho é o de avaliar o desempenho do sistema BRT da cidade de Lima, no Peru, especificamente Corredor Segregado de Alta Capacidade (COSAC I). Para tanto, foi adotada a metodologia de auxílio multicritério à decisão, que leva em conta tanto as variáveis quantitativas como as qualitativas na avaliação. Esta metodologia foi aplicada de forma abrangente, considerando não apenas os interesses do usuário, mas também os impactos que esse sistema provoca no meio urbano. Os resultados obtidos possibilitaram conhecer os pontos de vista e as necessidades dos atores, assim como o desempenho geral do sistema e o desempenho local para cada atributo Abstract: Cities need efficient transport systems, both for the movement of goods and people as to the realization of the fundamental activities. Therefore transport is characterized as one of the main activities to meet the growing needs of urban centers. One of the options adopted for urban public transport is the BRT (Bus Rapid Transit), which can meet the transportation needs with low cost of deployment, causing positive impacts in its area of influence. Therefore, BRT systems have been deployed in many cities in the world, which makes the performance evaluation of the transport mode a current need and of great importance for the proper development of urban centers. The objective of this study is to evaluate the performance of the BRT system of the city of Lima, Peru, specifically the Segregated Corridor of High Capacity (COSAC I). For this purpose, the methodology adopted was multicriteria decision aid, which takes into account both qualitative and quantitative variables in evaluating. This methodology was applied comprehensively, considering not only the user's interests, but also the impact that this system causes the urban environment. The results enabled us to know the views and needs of stakeholders, and the general performance of the system and the local performance for each attribute Mestrado Transportes Mestre em Engenharia Civil

Review of Road Hauliers' Measures for Increasing Transport Efficiency and Sustainability in Urban Freight Distribution

Scipedia content — Tue, 26 Jan 2021 15:57:52 +0100

Freight transport efficiency, as one proposed abatement strategy for transport related emissions, is a concept that has received much research attention during the last de-cade, often from the transport buyers’ perspective. In contrast, the aim of this thesis is to explore the subset concept of operational freight transport efficiency and how it affects transport related emissions from the perspective of the transport operator. The focus is on the transport operators and their interfaces with other actors such as tran-sport providers/forwarders, transport buyers, and the society. I open with a dissection of the term “operational freight transport efficiency.” I make these primarily semantic efforts to open up and introduce a few aspects that are commonly overlooked. The concept is argued to be “fuzzy”, in the sense that it means different things depending on who you ask, and a “wicked problem”, in the sense that the problem has no clear solutions with significant and present trade-offs. The methodology, or vessel, used in this thesis to launch a “critical spirit” is “phronetic social science”. After phronetically testing the efficiency measures, some recommendations are presented. A suggestion on operational decarbonisation is provided and the attitudes and trade-offs among the actors are explored. The thesis identifies a gap with respect to the absence of a common semantic definition of the concept of operational freight transport efficiency measures. The thesis proposes that the gap be filled with the following derived define-tion of operational freight transport efficiency: “A set of utilisation measures of time, space, vehicle, fuel and driver in the movement of goods”. From the operators point of view, as well as from an aggregated level, also missing are the trade-offs between environmental and economic considerations. Most operational freight transport effi-ciency improvement measures are likely to reduce emissions, however; it is probable that mere cost-reduction measures will not lead to reduced emissions in the long term. The traverse across these topics represented by the present thesis is offered as a theo-retical contribution to the discussion about defining what is meant by sustainable logistics. In other words, what the word sustainable means in a logistics context.

The Power of Electric Vehicles - Exploring the Value of Flexible Electricity Demand in a Multi-actor Context

Scipedia content — Tue, 26 Jan 2021 15:56:02 +0100

Electric vehicles (EVs) have the potential to play a crucial role in clean and intelligent power systems. The key to this potential lies in the flexibility that EVs provide by the ability to shift their electricity demand in time. This flexibility can be used to facilitate the integration of renewable energy sources by adjusting EV demand to the variable production of wind or solar energy. On the other hand, the same flexibility can be employed to reduce peaks in network load that could result from a massive adoption of EVs. This PhD thesis aims to improve the understanding of the value of flexible EV demand in the context of multi-actor power systems with a high share of renewable energy sources. We first explore flexible EV demand from a distribution network point of view, and then in the light of renewable energy integration. Moreover, we also bring these perspectives together and investigate mechanisms to align the different objectives related to the distribution networks and renewable energy integration. This thesis thus demonstrates the value of demand response in the sustainable power systems of the future.

Estimation et contrôle dynamique longitudinale d’un véhicule électrique avec moteurs-roue

Scipedia content — Tue, 26 Jan 2021 15:41:21 +0100

The main objective of the present thesis focuses on the integration of the in-wheel electric motors into the conception and control of road vehicles. The present thesis is the subject of the grant 186-654 (2010-2013) between the Laboratory of Signals and Systems (L2S-CNRS) and the French Institute of Petrol and New Energies (IFPEN). The thesis work has originally started from a vehicular electrification project, equipped with in-wheel electric motors at the rear axle, to obtain a full electric urban use and a standard extra-urban use with energy recovery at the rear axle in braking phases. The standard internal combustion engines have the disadvantage that complex estimation techniques are necessary to compute the instantaneous engine torque. At the same time, the actuators that control the braking system have some delays due to the hydraulic and mechanical circuits. These aspects represent the primary motivation for the introduction and study of the integration of the electric motor as unique propelling source for the vehicle. The advantages brought by the use of the electric motor are revealed and new techniques of control are set up to maximize its novelty. Control laws are constructed starting from the key feature of the electric motor, which is the fact that the torque transmitted at the wheel can be measured, depending on the current that passes through the motor. Another important feature of the electric motor is its response time, the independent control, as well as the fact that it can produce negative torques, in generator mode, to help decelerate the vehicle and store energy at the same time. Therefore, the novelty of the present work is that the in-wheel electric motor is considered to be the only control actuator signal in acceleration and deceleration phases, simplifying the architecture of the design of the vehicle and of the control laws. The control laws are focused on simplicity and rapidity in order to generate the torques which are transmitted at the wheels. To compute the adequate torques, estimation strategies are set up to produce reliable maximum friction estimation. Function of this maximum adherence available at the contact between the road and the tires, an adequate torque will be computed in order to achieve a stable wheel behavior in acceleration as well as in deceleration phases. The critical issue that was studied in this work was the non-linearity of the tire-road interaction characteristics and its complexity to estimate when it varies. The estimation strategy will have to detect all changes in the road-surface adherence and the computed control law should maintain the stability of the wheel even when the maximum friction changes. Perturbations and noise are also treated in order to test the robustness of the proposed estimation and control approaches.; L'objectif principal de cette thèse est l'étude de l'exploitation de systèmes moteurs-roues (machines électriques intégrées à la roue) pour le contrôle de la dynamique véhicule. Cette thèse est issue d'un co-financement (numéro 186-654, 2010-2013) entre le Laboratoire des Signaux et Systèmes (CNRS) et l'Institut Français du Pétrole et Énergies Nouvelles (IFPEN). Les avantages apportés par l'utilisation du moteur électrique sont avérés et de nouvelles techniques de contrôle sont développées pour optimiser son utilisation. Les lois de contrôle basent généralement sur la grandeur principale du moteur électrique: le couple transmis, qui peut être mesuré via le courant consommé. Une autre caractéristique importante du moteur électrique est son temps de réponse, avec le fait qu'il peut produire des couples négatifs, pour ralentir le véhicule, tout en stockant l'énergie. La nouveauté du présent travail est de considérer le moteur-roue électrique comme seul signal de contrôle dans des phases d'accélération et des phases de ralentissement, simplifiant l'architecture de la conception du véhicule et des lois de contrôle. Pour répondre à la demande conducteur tout en préservant un comportement sain du véhicule, des stratégies d'estimation de la limite d'adhérence seront présentées. En fonction de cette adhérence maximale disponible entre la route et les pneus, un couple adéquat sera calculé pour assurer un comportement stable dans des phases d'accélération aussi bien que de freinage. L'aspect critique étudié dans ce travail est la non-linéarité des caractéristiques d'interaction entre la route et le pneu et la complexité de son estimation dans des conditions variables. La stratégie d'estimation devra détecter tous les changements d'adhérence de route et la loi de contrôle calculée devra maintenir la stabilité véhicule même lorsque la friction maximale change. Certaines formes de perturbation et de bruit seront également prises en compte afin de tester la robustesse des approches d'estimation et de contrôle proposés. Parmi les systèmes de sécurité active les plus importants en phase d'accélération, le système de contrôle de traction (TCS) rétablit la traction si les roues commencent à patiner et le programme de stabilité électronique (ESP) intervient pour prévenir une perte menaçante du contrôle latéral du véhicule. Dans le cas du freinage, le système décisif est le système d'antiblocage (ou ABS), qui empêche le blocage des roues. On peut trouver d'autres systèmes embarqués, comme le système de distribution de force de freinage électronique (EBD), qui assure une distribution optimale de la force de freinage transmise aux roues, pour éviter de déraper et assure un ralentissement stable du véhicule. Les systèmes embarqués qui fournissent les estimations doivent être robustes aux bruits de mesure et aux perturbations. A fortiori, ces calculs doivent être faits en temps réel, donc une complexité réduite et une réponse rapide de la loi de contrôle sont nécessaires. Enfin, l'environnement dans lequel le véhicule fonctionne est dynamique, les caractéristiques d'adhérence peuvent varier en fonction de l'état de la route et de la météo. Ainsi, on ne peut prévoir les réactions du conducteur pouvant influencer la réponse globale du véhicule dans des situations d'urgence. Le contrôleur devrait prendre en compte tous ces aspects pour préserver un comportement stable du véhicule. Bien que le contrôle latéral du véhicule présente une importance majeure dans la stabilité globale du véhicule, le présent travail est concentré sur le contrôle longitudinal du véhicule, puisqu'il représente le point de départ de la dynamique véhicule.

Implantação integrada de infraestruturas de transportes : Caso do rodoanel e ferroanel no trecho norte, em São Paulo

Scipedia content — Tue, 26 Jan 2021 15:37:00 +0100

Orientador: Carlos Alberto Bandeira Guimarães Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo Made available in DSpace on 2018-08-26T04:42:12Z (GMT). No. of bitstreams: 1 Oliveira_DalianaDamacenoGilde_M.pdf: 964791 bytes, checksum: 7035668583ec53d4289bd006d1fa2a90 (MD5) Previous issue date: 2014 Resumo: Os estudos de implantação do Trecho Norte dos empreendimentos Rodoanel e Ferroanel, com traçados próximos, pode potencializar e viabilizar uma série de ações conjuntas, como o compartilhamento das plataformas de terraplenagem em alguns segmentos, otimizando as interferências, drenagem, tratamentos de solos moles, contenções, obras de proteção ambiental, remanejamento de interferências, adequações funcionais dos sistemas viários lindeiros e áreas de apoio, além de procurar minimizar as necessidades de desapropriações e reassentamentos complementares aos previstos para o Rodoanel, reduzindo de forma significativa os custos em relação a hipótese dos empreendimentos a serem implantados independentemente. Este trabalho, utilizando como suporte metodológico o estudo de caso, estuda a integração dos modais rodoviários e ferroviários e a apresenta as alternativas das implantações nas formas isoladas e faz um comparativo da possibilidade de compatibilização das implantações das linhas férreas com a rodovia. E apresenta como resultado, uma opção para os problemas de infraestrutura de transporte no Brasil, a possibilidade de se pensar em uma integração na construção dos vários modais básicos Abstract: The implantation studies of road and rail ring roads in São Paulo can enhance and facilitate a series of joint actions , such as sharing of earthwork in some segments platforms , optimizing interference , drainage, soft soil treatment , containment , protection works environmental , relocation interference , functional adaptations of the bordering road systems and support areas , and seek to minimize the needs of expropriation and resettlement complementary to that provided to the Beltway , significantly reducing costs in relation to the hypothesis of projects to be implemented independently . This work , using as methodological support the case study examines the integration of road and rail modes and presents alternative deployments in isolated forms and makes a comparison of the possibility of compatibility between implementations of the railways with the highway . And as a result has an option for the problems of transportation infrastructure in Brazil , the possibility of thinking about integration in the construction of several basic modes Mestrado Transportes Mestra em Engenharia Civil

Enabling Continuous Descent Operations in High-Density Traffic

Scipedia content — Tue, 26 Jan 2021 15:30:53 +0100

The Air Traffic Management (ATM) community strives to reduce the environmental impact per flight. Continuous Descent Operation (CDO) has been identified by the ATM community as one of the operational improvements that could reduce aviation’s environmental impact, both in terms of aircraft noise and gaseous emissions. In the current ATM system, CDOs are only feasible in low-density traffic. The ultimate goal is an ATM system that facilitates CDOs in high-density traffic. This research described in this thesis focused on two features of such an ATM system: decision support that enables the air traffic controller to accurately set up traffic for CDO, and delegation of the spacing task to the flight crew during the CDO. Two enablers are real-time availability of meteorological data, and accurate trajectory prediction. In this thesis new methods were developed and validated to infer wind, air pressure, and air temperature profiles from aircraft surveillance data. Trajectory prediction was defined as a machine learning problem, enabling predictions based on historic aircraft trajectory and meteorological data without the need for explicit modeling of the aircraft performance and procedures. A decision support tool was developed further and tested using a human-in-the-loop experiment. The tool enabled the subjects to set up traffic for CDO in high-density traffic at an acceptable work load level and high level of situation awareness. Monte-Carlo simulations were carried out to assess the runway capacity that can be achieved when delegating the spacing task to the flight crew. These simulations showed the feasibility of CDOs in high-density traffic.

Non-isolated integrated motor drive and battery charger based on the split-phase PM motor for plug-in vehicles

Scipedia content — Tue, 26 Jan 2021 14:26:48 +0100

In electric vehicles and plug-in hybrid electric vehicles, the utility grid charges the vehicle battery through a battery charger. Different solutions have been proposed to reduce the size and cost of the charger. One solution to achieve this is to include the devices used in the traction circuit in the charger circuit; this is called an integrated motor drive and battery charger. A split-phase PM motor, a motor with double set of windings, gives the opportunity to implement different winding configurations to keep the motor at stand-still when it is connected to the grid. The motor will act as inductors in the charging process. This is an advantageous chance in order to use the motor in an integrated battery charger. In the current thesis, a non-isolated battery charger based on some of these special configurations is tested. Two different PM motors are utilized in proposed chargers. Different windings configurations have been practically tested. The main challenge is to keep the motor in stand-still during charge operation. Practical results show that with proposed schemes, the motors are in stand-still. A National Instrument CompactRIO system is used to perform the control of the integrated charger in the practical implementation. A brief explanation of the practical setup and a user guide for running the experimental system is included as well. Ingeniería Industrial

Electric vehicle technological battle: an analysis of GM´s automotive race for the dominant design

Scipedia content — Tue, 26 Jan 2021 14:03:47 +0100

presente pesquisa viabilizou, possivelmente, a expansão do arcabouço teórico desenvolvido por Suarez (2004) e Lynn et al. (1996), seguindo a mesma direção dos resultados obtidos na pesquisa longitudinal desenvolvida por Yu et al. (2011). Desenvolvemos um estudo descritivo de modo a analisar um período de 42 anos com o objetivo de entender os fatores que influenciaram a trajetória do desenvolvimento da tecnologia do veículo elétrico na GM de modo que utilizamos o arcabouço teórico desenvolvido por Suarez (2004) como norteador das observações empíricas. Coletamos dados secundários da tecnologia de baterias referente a fase um (realização de P&D) e dados secundários da tecnologia do veículo elétrico referente às fases dois (protótipos) e fase três (criação de mercado) para a construção do estudo de caso. As observações dessas fases viabilizaram os seguintes resultados: a possível expansão do arcabouço conceitual do Suarez (2004) em relação ao nível da firma (sondagem e aprendizagem tecnológica, sondagem e aprendizagem mercadológica e transferência de conhecimento) e ao nível do ambiente (setores industriais associados, pressão social, política internacional e questão econômica); e a possível ampliação da vertente teórica de sondagem e aprendizagem mercadológica desenvolvida por Lynn et al. (1996) no sentido de constatarmos a sondagem e aprendizagem tecnológica em um momento anterior a sondagem e aprendizagem mercadológica. Na década passada, iniciou-se um processo de efervescência de novos entrantes na indústria do veículo elétrico e, nessa década, duas das principais montadoras mundiais (GM e Nissan) lançaram os seus primeiros veículos elétricos para serem produzidos em larga escala. Essas evidências empíricas indicam uma possibilidade real da tecnologia do veículo elétrico estar em um estágio de maturidade que viabilize a realização do processo de transição tecnológica indicada no arcabouço conceitual desenvolvido por Utterback e Abernathy, em 1975. Nesse sentido, os resultados teóricos obtidos nessa pesquisa podem apoiar o processo de tomada de decisão no contexto de incentivo a essa tecnologia tanto da perspectiva da firma quanto da perspectiva do governo. In alignment with the results obtained in the longitudinal research conducted by Yu et al. (2011), the present study possibly enabled the expansion of the theoretical framework developed by Suarez (2004) and Lynn et al. (1996). A descriptive study was developed so as to analyse a 42 year period with views to understanding the factors which influenced the course of development of electric vehicle technology at GM. Thus, to guide empirical observations, the theoretical framework developed by Suarez (2004) was employed. To build the study case, phase one (execution of R&D) battery technology and phase two (prototypes) and three (market shaping) electric vehicle technology secondary data was collected. Findings observed in these phases gave rise to the following results: the possible expansion of Suarez´s (2004) conceptual framework at corporate level (technological survey and learnings, market survey and learnings and knowledge transfer) and at environment level (associated industrial segments, social pressure, international politics and economic issues); and the possible extension of the theoretical market probe and learning line of thought developed by Lynn et al. (1996) in as much as the identification of the occurrence of technological probe and learning, at a moment preceding that of market probe and learning, is concerned. Over the last decade, a new entrant commotion process sprung within the electric vehicle industry and during this decade, two of the top world manufacturers (GM and Nissan) launched their first electrical vehicles for mass production purposes. This empirical evidence indicates that currently, there is an effective possibility of electric vehicle technology being at a stage of maturity whereby the technological transition mentioned in the conceptual framework developed by Utterback and Abernathy in 1975, is feasible. To this effect, the theoretical results obtained in this study may support decision processes in as much as incentives are concerned, both from a corporate and government perspective.

Scalable beaconing for cooperative adaptive cruise control

Scipedia content — Tue, 26 Jan 2021 13:59:42 +0100

Over the past two hundred years, automotive technology has evolved from mechanised horse carriage to high-tech systems which pack more computing power than the entire space program that put Neil Armstrong on the moon. Hand-in-hand with this evolution came a proliferation of ownership and use of cars. This enormous success causes one of modern society’s largest problems: where many vehicles accumulate, traffic congestion occurs. To a large degree, the cause of traffic congestion lies in the poor ability of the human driver to control the (longitudinal) motion of the vehicle under congested traffic circumstances. This leads to so-called string instabilities or shock waves, traveling against the flow of traffic. The traffic flow performance can be improved if the control of acceleration and deceleration is automated. Presently available solutions use radar or lidar to detect and measure the distance to the vehicle in front, and a cruise controller automatically reacts by adjusting the vehicle speed. However, the performance of these systems is not sufficient to prevent shock waves, predominantly due to the delay introduced by the sensors. The Cooperative Adaptive Cruise Control (CACC) is a system which circumvents this by using wireless communication to exchange information about vehicle dynamics using the periodic transmission of so-called beacon messages. The technology proposed for this wireless communication is IEEE 802.11p, a modified version of the IEEE 802.11a designed for Wireless LAN applications. However, the wireless medium succumbs to a congested state in a similar fashion as the traffic on the road in response to an increase of the traffic density. This dissertation focusses on the beaconing communication, used to generate a cooperative awareness in each vehicle. Given the real-time nature of the CACC system, it is important that the information in the cooperative awareness is accurate and fresh, even under an increasing number of communicating nodes in near vicinity. To this end, beaconing is evaluated through analytical modelling, discrete-event simulation and proof-of-concept implementations. The purpose is to determine the scalability limits of the IEEE 802.11p Medium Access Control mechanism when used for beaconing, and find and address bottlenecks. In this disseration, detailed analytical models of the Distributed Coordination Function (DCF) and the Enhanced Distributed Channel Access (EDCA) are proposed, validated, and compared. Various mechanisms which impact the scalability of a beaconing system are described and evaluated using both these analytical and simulation models. In particular, an extensive comparison between the DCF and EDCA access mechanism variants of IEEE 802.11 is performed based on their performance in the face of increasing traffic density. The conclusion is that, although IEEE 802.11p defines the EDCA to be used, the DCF is a more favourable access mechanism for the broadcast transmission of beacon messages. Under both access methods, the use of the EIFS is found to be redundant because the beacon channel is broadcast-only. Furthermore, the periodic channel switching defined by IEEE 1609.4, which defines a way to use single-radio IEEE 802.11p on multiple channels in a time-division fashion, has a detrimental effect on beaconing performance. In addition, the way beacon messages are buffered and scheduled for transmission is evaluated. We conclude that it is beneficial to use a dropping policy which drops the oldest information in the queue, as opposed to the most recent arrival as is often implemented. This method is coined the Oldest Packet Drop (OPD) mechanism and is described and evaluated in detail. The outlook of a CACC application operating on beacons transmitted using IEEE 802.11p is good. However, care has to be taken that the system does not become congested. This dissertation provides a set of tools to estimate when the channel becomes congested, and to evaluate the impact of various design choices on communication performance.

Traffic Engineering and Characterization of High-Rate Large-Sized Flows

Scipedia content — Tue, 26 Jan 2021 13:54:14 +0100

High-rate large-sized (α) flows have adverse effects on delay-sensitive flows. Research-and- education network providers are interested in identifying such flows within their networks, and directing these flows to virtual circuits. To achieve this goal, a design was proposed for a hybrid network traffic engineering system (HNTES) that would run on an external server, gather NetFlow records from routers, analyze these records to identify α-flow source/destination address prefixes, configure firewall filter rules at ingress routers to extract future α flows and redirect them to pro- visioned virtual circuits. This thesis presents an evaluation of this HNTES design using NetFlow records collected over a 7-month period from four ESnet routers. The results show that the HNTES effectiveness was above 90% for NetFlow records collected at edge routers, which corresponded to file downloads from Department of Energy (DOE) laboratories, while the effectiveness was lower for peering routers whose NetFlow records corresponded to file uploads. With further investigation, we found that uploads were less frequent and involved fewer source/destination pairs than downloads. The thesis also describes an algorithm for characterizing the size, duration, average rate, and frequency of α flows, from NetFlow records. The algorithm was validated using independently collected usage logs from application servers. This algorithm can be used in a network management system for providers interested in these types of flows, such as research-and-education network providers whose customers move large scientific datasets. We executed the algorithm on the same NetFlow records used in the HNTES evaluation. Flows moving datasets as large as 811 GB and at rates as high as 5.7 Gbps were observed. Some source-destination pairs were found to repeatedly create α flows. An analysis of the rates of the 1596 repeated α flows created by one pair showed considerable variance, with minimum rate of 100 Mbps, maximum rate of 536 Mbps, and a coefficient of variation of 30%.

Delay Management and Dispatching in Railways

Scipedia content — Tue, 26 Jan 2021 13:53:12 +0100

xtabstractPassenger railway transportation plays a crucial role in the mobility in Europe. Since the privatization of the railway sector in the 90s, passenger satisfaction has become an important performance indicator in this sector. A key aspect for passengers is the reliability of transfers between trains. When a train arrives at the station with a delay, passengers might miss their connection if the next train departs on time. These passengers then prefer the connecting train to wait, but this introduces delays for many other passengers. Delay Management is a field in railway operations that deals with this situation. It determines whether a connecting train should wait for the passengers that arrive with a delayed train or should depart on time. In this thesis, we apply techniques from Operations Research to develop models and solution approaches for Delay Management. The objective in our models is the minimization of passenger delay. First, we extend the classical delay management model with passenger rerouting. This allows us to compute the exact delays for passengers. We develop an exact algorithm and several heuristics to solve this extension. Then, we incorporate the limited capacity of the stations in our models. Stations are the bottlenecks of the railway infrastructure, where delays of one train can easily propagate to other trains. When optimizing the wait-depart decisions, these secondary delays should be considered. We therefore develop an integrated model that includes headway constraints for trains on the same track in the station and an iterative approach that evaluates the timetable microscopically.

The road to independence : a study of reducing fossil fuel import dependency for private land transport on Mauritius

Scipedia content — Tue, 26 Jan 2021 13:52:59 +0100

Imported fossil fuels accounted for 83.8% of the primary energy demand on Mauritius in 2011. 36.4% of the fossil fuels imported were used in the transport sector. This thesis examines how Mauritius can reduce their import dependency on fossil fuels for private land transport by use of biofuels and electric vehicles. Nine models for possible fuel consumption in private land transport are used. These models are based on three different fuel intensities and three different average distances travelled each day. It is found that implementing E10 or E20 ethanol blends in gasoline-fuelled cars/dual-purpose vehicles have the potential of reducing fossil fuel imports for private land transport by 1.4% to 5.6% or 2.8% to 11.2% depending on the consumption model. The required ethanol for such blends can be produced from by-products of the existing sugar industry on the island. Four scenarios for electricity generation to fuel electric vehicles were also considered; Scenarios A and B models an electricity generation source mix consistent with the 2010 mix and a government target mix for 2025, scenario C models electricity generation exclusively from coal and scenario D models electricity generation only from renewable energy resources. All scenarios result in a decrease of required fossil fuels import for private land transport when replacing conventional vehicles with electric vehicles, with scenario C showing the least and scenario D showing the largest decrease. However an all-electric car fleet can more than double the electricity demand if the charging coincides with the peak electricity demand. As a consequence, measures must be put in place to mitigate this risk. Some measures to this effect, such as a vehicle-to-grid system, will enable electric vehicle batteries to act as extra energy and power capacity for the electric grid and thus facilitate a higher share of renewable energy in the general electricity generation on Mauritius. An electric vehicle fleet fuelled with electricity generated from renewable energy sources should therefore be the long-term goal for private land transport on Mauritius. Many Strong Voices, Norad, Tekn

U.S. Governmental incentives and policies for investment in electric vehicles and infrastructure

Scipedia content — Tue, 26 Jan 2021 13:48:01 +0100

The purpose of study is to research the development of electric vehicle technology in the United States. This study describes the United States public policies towards electric vehicle technology and system of innovation approaches. The government roles with the help of national system of innovation have been also covered in this study. The point of departure was the study of available literature and U.S energy policy acts which illustrates that the break-through in electric vehicles still not only depended on better battery technology and infrastructure for charging stations but also on social, economic and political factors. The important actors involved in the process are both at local and international level are private firms, governmental departments, research and development (R&D) institutes, nongovernment organizations (NGO’s) and environmental organizations etc. The arguments which are put forward in the background of development of such technologies are to reduce dependence on foreign oil and to reduce emissions of harmful gasses.

DPP: Dual Path PKI for Secure Aircraft Data Communication

Scipedia content — Tue, 26 Jan 2021 13:43:15 +0100

Through application of modern technology, aviation systems are becoming more automated and are relying less on antiquated air traffic control (ATC) voice systems. Aircraft are now able to wirelessly broadcast and receive identity and location information using transponder technology. This helps reduce controller workload and allows the aircraft to take more responsibility for maintaining safe separation. However, these systems lack source authentication methods or the ability to check the integrity of message content. This opens the door for hackers to potentially create fraudulent messages or manipulate message content. "br /""br /"This thesis presents a solution to handling many of the potential security issues in aircraft data communication. This is accomplished through the implementation of a Dual Path PKI (DPP) design which includes a novel approach to handling certificate revocation through session certificates. DPP defines two authentication protocols, one between aircraft and another between aircraft and ATC, to achieve source authentication. Digital signature technology is utilized to achieve message content and source integrity as well as enable bootstrapping DPP into current ATC systems. DPP employs cutting-edge elliptic curve cryptography (ECC) algorithms to increase performance and reduce overhead. "br /""br /"It is found that the DPP design successfully mitigates several of the cyber security concerns in aircraft and ATC data communications. An implementation of the design shows that anticipated ATC systems can accommodate the additional processing power and bandwidth required by DPP to successfully achieve system integrity and security. Master of Science

The design and development of a vehicle chassis for a Formula SAE competition car

Scipedia content — Tue, 26 Jan 2021 13:42:43 +0100

MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014 The Formula SAE is a student based competition organised by SAE International where engineering students from a university design, develop and test a formula-style race car prototype to compete against other universities. The competition car needs to satisfy the competition rules set out by the organisers. The competition strives to stimulate original, creative problem solving together with innovative engineering design practices. In any race environment, the primary goal is always to be as competitive as possible. Due to the competitive nature of motor sport, vehicle components need to withstand various and severe stresses. The components of a race car vehicle are responsible for the vehicle’s handling characteristics and reliability. The chassis is a crucial and integral component of a Formula SAE competition car, primarily responsible for the vehicle’s performance characteristics. The chassis is the structural component that accommodates all the other components. A Formula SAE chassis is a structure that requires high torsional stiffness, low weight as well as the necessary strength properties. In this study, multiple Formula SAE chassis were designed and developed using computer aided design software. Each concept’s torsional stiffness, weight and strength properties were tested using finite element analysis software. The different concepts consisted of different design techniques and applications. All the concepts were analysed and assessed, leading to the identification of an acceptable prototype. The prototype was manufactured for experimental tests. The designed chassis complied with the Formula SAE rules and regulations. The weight, torsional stiffness and strength characteristics of the designed chassis frame were also favourable compared to accepted standards for Formula SAE chassis frames. The manufactured chassis was prepared for experimental tests in order to validate the simulation results produced by the finite element analysis. The torsional stiffness, weight and strength were experimentally determined and the results were compared with the corresponding simulations results. The comparison of the experimental and simulated results enabled the validation of the finite element analysis software. The study draws conclusions about the use of computer aided design and finite element analysis software as a design tool for the development of a Formula SAE chassis. Closure about the study is provided with general conclusions, recommendations and research possibilities for future studies. Master

Making travel sustainable with ICT? : The social practice of travel planning and travel information use in everyday life

Scipedia content — Tue, 26 Jan 2021 13:25:58 +0100

dopting the perspective of the traveller, this thesis examines how travel plans are actually made in the everyday situation and how information is used and drawn on when planning the many, often unremarkable, trips of ordinary urban life. Ethnographical field studies in southern Stockholm, Sweden, employing a practice theory perspective showed that people use a vast mixture of different types of information when planning and making trips. Therefore, the concept of travel information should be defined broadly enough to encompass informal, formal, analogue and digital types of travel information. Then, and only then, is it possible to perceive the interactions between these and see their potential as a change factor for sustainable city travel. In relation to this, situations when travel information was not used, were also identified in the qualitative data and are acknowledged and discussed in the thesis. Travel planning is in everyday practice undertaken little by little, squeezed in between other activities of daily life. It is a process more extended in time, space and content than the limited search for information about the best way to get from A to B, assumed and facilitated in many existing travel information services. Travel planning is closely connected to the overall scheduling of activities (planning of life) and thus spans much larger time frames than the single trip. Planning travel also includes consideration of issues such as preparations needed (things to be done before departure/brought on the trip); managing vehicles and equipment in time and space (getting the bicycle/car home again or safely parked); the weather (current and forecast); social relations (the potential of different travel options for relationship building or conflict triggering); social norms (e.g. of 'good parenting' or 'proper behaviour on public transport'); and health issues (wanting exercise or inability to manage stairs/luggage). The qualitative data revealed that travel information is sometimes perceived and used as a security blanket, i.e. something to hold on to and give the traveller courage on the trip until they are safe at their destination. It also showed that travel planning, depending on life situation, can be experienced as either a house of cards, i.e. if anything changes the whole house collapses and has to be rebuilt to a different layout, or a prefab building, i.e. the same prefabricated pieces are joined together in more or less the same pattern every time. Recent decades have seen rapid growth in ICT services relating to transportation. Different types of travel information services have been proposed as a means to decrease the environmental impacts of transportation through effecting behavioural change. Taking the empirical 4 insights provided by this thesis into travel planning and travel information use in practice, it is clear that travel information services of tomorrow, if connected to other ICT systems in everyday life, could be designed in a way that broadens their horizon of assistance in supporting travel planning processes in everyday life. Although, as this thesis demonstrates, the role and potential of travel information services and ICT in the work of achieving sustainable mobility should be discussed from a perspective critical of overly linear perceptions and instrumental starting points. Denna avhandling tar resenärens perspektiv, och undersöker från vardagslivets horisont hur resor egentligen planeras, och hur information används när de många, ofta obemärkta, vardagsresorna görs i staden. Etnografiska fältstudier i södra Stockholm, gjorda och analyserade med ett praktikteoriperspektiv, visar att människor använder sig av många olika typer av information för att planera och genomföra sina resor. Därför bör begreppet reseinformation definieras vitt nog att rymma både informella, formella, analoga och digitala typer av reseinformation. Först då är det möjligt att iaktta interaktioner mellan dessa, och också se informationens eventuella potential som förändringsfaktor för hållbart stadsresande. Även situationer när reseinformation inte används uppmärksammas och diskuteras. Reseplanering är i vardaglig praktik något som sker lite i taget, i mellanrummen mellan andra sysslor och aktiviteter. Det är en process mer förgrenad i tid, rum och innehåll än den avgränsade sökning efter information om bästa sättet att ta sig mellan A och B som många existerande IT-baserade reseplanerare verkar förutsätta och i dagsläget assisterar. Reseplanering är starkt knutet till den övergripande planeringen av aktiviteter i livet, och reseplanering har därför oftast ett vidare tidsspann än endast en resa. Planering av resor inkluderar även hänsyn till faktorer som nödvändiga förberedelser (saker att göra innan avfärd/ta med sig på resan); hantering av fordon och bagage i tid och rum (få hem cykeln/bilen igen eller få den säkert parkerad); vädret (nuvarande och prognostiserat); sociala relationer (potentialen för konflikter/positiv samvaro vid olika färdmedelsval); sociala normer (om gott föräldraskap eller hur man för sig på kollektiva färdmedel); och hälsoaspekter (vilja till motion eller oförmåga att gå i trappor). Fältarbetet gjorde tydligt att reseinformation ibland används som en snuttefilt – något att ty sig till och hålla i handen på okänt territorium tills du har kommit till målet för din resa. Reseplanering kan också, beroende på livssituation, antingen upplevas och liknas vid husbygge med prefabricerade element – samma standardiserade, välkända bitar sammanfogas på ungefär samma sätt varje gång; eller också ett korthus – om någonting ändras brakar hela huset ihop, och måste byggas upp igen med en helt annan design. Under de senaste decennierna har det skett en snabb utveckling av IT-lösningar på transportområdet. Olika typer av reseinformationstjänster har föreslagits som ett verktyg för att ändra resebeteenden och därmed minska transporters miljöpåverkan. Med utgångspunkt från studiens 6 empiriska insikter i hur reseplanering går till i praktiken, och hur reseinformation används blir det tydligt att morgondagens reseplanerartjänster, om de kopplades ihop med andra digitala system vi använder i vår vardag, skulle kunna utformas på ett sätt som utvidgar systemets "assistanshorisont" för att bättre passa ihop med reseplaneringspraktikerna i vår vardag. Potentialen och rollen för reseinformationstjänster och IT i arbetet med att minska transporters miljöpåverkan bör diskuteras från ett perspektiv som är kritiskt till alltför linjära och instrumentella utgångspunkter, vilket denna avhandling bidrar till. "p"QC 20141030

Effects of the EUROCOMBI on the automotive industry logistics in Austria

Scipedia content — Tue, 26 Jan 2021 13:25:44 +0100

von Christian Moser Wien, Techn. Univ. u. Bratislava, Techn. Univ., Master Thesis, 2014

Internet das coisas aplicada a sistemas de transportes inteligentes : estudo de caso em controle de acesso

Scipedia content — Tue, 26 Jan 2021 13:23:01 +0100

Orientador: Niederauer Mastelari Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica Made available in DSpace on 2018-08-24T18:11:18Z (GMT). No. of bitstreams: 1 Cardoso_RaulMariano_M.pdf: 9927638 bytes, checksum: f9633c7839661e2f914d88b7d438913e (MD5) Previous issue date: 2014 Resumo: Os computadores como conhecemos não são mais a maioria de dispositivos que se comunicam utilizando a Internet. Há alguns anos uma tendência pode ser observada neste sentido: "coisas" recebem pequenos computadores, e são representadas virtualmente, gerando informações de valor aos seus usuários. Esta nova fase de desenvolvimento da sociedade da informação é conhecida como "Internet das Coisas" e tem afetado tanto a relação das pessoas com a vida cotidiana, quanto os modelos de negócio correntes. Este trabalho mostra como esta tendência tecnológica, inserida no contexto dos Sistemas de Transportes, pode gerar aplicações de grande relevância. Com este objetivo, metodologias que pudessem embasar o projeto foram buscadas. Um modelo arquitetural de referência foi utilizado para embasar o projeto e design de um sistema distribuído focado em aplicações específicas. A tecnologia RFID foi utilizada, com leitores e etiquetas eletrônicas, para projetar um arranjo de dispositivos que identifique os veículos e detecte sua presença nas entradas e saídas de um local restrito de interesse. Microcontroladores de baixo custo, de código aberto, tanto em hardware quanto em software, e com capacidade de se comunicar através da Internet também foram definidos por este projeto. Localmente, estes dispositivos filtram informações, mantêm bases de dados reduzidas, monitoram sensores e controlam atuadores. Para gerenciar os dispositivos desta rede, é proposta a utilização de serviços na rede, estabelecendo assim a possibilidade de uma arquitetura em nuvem. Este servidor, por sua vez, deve coordenar os dispositivos distribuídos, obtendo informações da rede que devem sincronizar os bancos de dados e também prover informações de estado dos controladores. O foco principal é o estabelecimento de uma arquitetura e infraestrutura que possam suportar as aplicações propostas. Um estudo de caso foi realizado considerando o campus da Universidade Estadual de Campinas. A primeira aplicação viável de um projeto como este é o controle de acesso veicular ao campus universitário, através da implantação de leitores RFID nas portarias, em conjunto com controladores, cancelas automáticas e sensores de presença. Isso motivou o desenvolvimento de uma prova de conceito. A instrumentação das portarias permite que os veículos sejam automaticamente identificados quando adentram o espaço restrito do campus, gerando informações de valor para outras aplicações possíveis. Dentre as aplicações previstas estão: controle de estacionamento privativo automático, sinalização interativa através de placas eletrônicas, informação de horários de transporte coletivo e elaboração de relatórios periódicos sobre o trânsito. Para que todas estas aplicações sejam disponibilizadas a comunidade, serão necessários trabalhos futuros de pesquisa e desenvolvimento Abstract: Computers as we know are no longer the majority of devices that communicate using the Internet. A few ago years a trend can be observed in this direction: "things" get small computers, and are represented virtually generating information of value to its users. This new phase of development of the information society is known as the "Internet of Things" and has affected both people's relationship with everyday life, as the current business models. This work shows how this technological trend, inside the context of Transportation Systems, can generate highly relevant applications. With this objective, methodologies that could base the project were sought. An architectural reference model was used to support the project and design of a distributed system focused on specific applications. RFID technology was used with electronic tags and readers, to develop a devices arrangement that identifies vehicles and detect their presence in the inputs and outputs of a restricted location of interest. Low cost, open source and Internet ready devices were also described for work¿s interest. Locally, these devices filter information, maintain reduced data bases, monitor sensors and control actuators. To manage the devices was proposed the use of network services, establishing the possibility of cloud architecture. The server must coordinate the distributed devices, getting information from the network that must synchronize the databases and also provide status information of the controllers. The main focus is to establish an architecture and infrastructure that can support the proposed applications. A case study was designed aiming the campus of the State University of Campinas. The first viable implementation of such a project is the control of vehicular access to the campus, through the installation of RFID readers, controllers, automatic barriers and presence sensors. That result in a deployed proof of concept. The instrumentation of the campus access allows vehicles to be automatically identified when they enter the restricted space of the campus, generating valuable information for other possible applications. Among the intended applications include: automatic control of private parking, signaling through interactive electronic boards, information on public transportation schedules and reporting generation about transit. In order to all these applications are available for the community, needed further in research and development Mestrado Mecanica dos Sólidos e Projeto Mecanico Mestre em Engenharia Mecânic

Contributions to road safety: from abstractions and control theory to real solutions, discussion and evaluation

Scipedia content — Tue, 26 Jan 2021 13:20:23 +0100

This manuscript aims to describe my career in the transportation domain, putting in evidence my contributions in different levels, as for example thesis advising, teaching, research animation and coordination, projects construction and participation in expert committees, among others, besides my scientific research itself. The goal, besides the HDR diploma itself, is to show very clearly, including to myself, this 'pack' of contributions in order to look for better contributions to the transportation and control communities or to other communities in the future, and also which research directions I will define to work on in the following. I obtained my PhD degree in the Laboratoire des Signaux et Systèmes - L2S 1 in collaboration with MIT, in 2001, having worked in a purely theoretical automatic control topic scarcely known in the literature - the adaptive control of systems with nonlinear parameterization problem. Arriving in 2002 as a permanent researcher to the former LCPC (Laboratoire Central des Ponts et haussées), now called IFSTTAR (Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux), I have been faced to real problems to solve in practice, and faced to the new community of transportation, with a completely different philosophy of work. I have nowadays this double vision - of the very applied transportation domain with concrete problems to be solved that touch the citizen every day, and the vision of a very rich high-level theoretical research in automatic control with powerful tools to solve the real problems, or on the other hand, with control problems that appear because of the need for new tools to solve the real problems. I consider this as an important characteristic for my future contributions. Besides the knowledge in Transportation itself, my eleven years of career in IFSTTAR gave me as well the following new features : 1. From the individual research, I have learned also how to coordinate work (in projects for example, as in the PReVAL sub-project of the European PReVENT project, in which I co-leaded one workpackage, or for research teams, as the control team of LIVIC, coordinated by myself from 2006 to 2009). I have also learned how to animate research (by coordinating research working groups or organizing scientific events and workshops - see for example the working group RSEI and the related scientific event below that I have organized in June 2012) and how to advise students. 2. Besides the double vision I have described above, the experience gave me also the acquisition of a quite multidisciplinary view of the problems in the domain. Firstly, arriving in LIVIC, in the frame of the French consortium ARCOS, I have worked for two years in close cooperation with experts in cognitive sciences (the PsyCoTech group from IRCCyN, Nantes) on designing driving assistance systems to a human driver. After this work, I have continued the collaboration with experts in human sciences within the PReVAL subproject of PReVENT on driving assistance systems evaluation and within the French ANR PARTAGE project, that I have constructed together with the PsyCoTec team of IRCCyN and leaded the IFSTTAR partner for one year. In a dition, through my participation in PReVENT at dirent levels (in two meetings of the Core Group, in PReVAL by co-leading the workpackage 3 on Technical Evaluation of ADAS - ADAS is the shortcut for Advanced Driving Assistance Systems - and in the SAFELANE subproject), I have learned many different aspects of ITS systems. I consider this as an add-on value for my 'pack of knowledge'. 3. What I call "from abstractions to real problems : coming back and forth to solve these real problems" has been matured in my mind, and I am very grateful to my students, with whom I have learned and that helped me in this maturing process. By this sentence, I mean, with a problem to solve in hands, and after building an abstraction, or a simplified view of the problem, and the design of a solution, how to apply it, and to come back again to the theory to change it and to come back to the practice, and so on. This is exactly one of the pillars of the NoE HYCON2, for making interact the theory with the application domains. 4. Considering a problem inserted into the societal context, or inserted within its related context, has been another maturing for myself that I consider very important, notably in the transportation domain, that represents a very complex context containing many different parameters, scenarios and objectives and in addition all the uncertainties linked to the human behavior. I think that it is very important to have a very large view of the context in which the specific problem we are treating is placed. Without this, one cannot say in most of the cases, from my point of view, that the problem is solved. This point will be discussed in Chapter 9.5. 5. Another point that I consider important and where I have been contributing recently is the road mapping work. The acquisition of the multidisciplinary knowledge and a larger view of the domain that I have mentioned in the preceding items, together with my theoretical knowledge in automatic control, allowed myself to start contributing to theroad mapping work in Transportation (through my participation in the imobility forum, in HYCON2 and the in the support action T-Area-SoS on Systems of Systems - all these actions to give advice to the European Commission on the priority areas to be considered in the new Calls, notably in the frame of the H2020 program). I had also the pleasure of opening again books and thesis that I had studied in my PhD work, this time now for advising students in the frame of other very different problems. The very beautiful thesis of Mikael Johansson, Lund University, on piecewise linear systems stability theory is an example. My previous study on switched systems, and the implication of switched Lyapunov functions on stability helped me also in advising my students (Post-Docs, PhD, and M.Sc. students), this time for real applications, with very interesting results blooming up from their work. I realize also that the experience that I have described in the five items above must be put in favor of students since this kind of knowledge cannot be found in the books. Concluding, in these last eleven years, from 2002 to 2013, I could bring to the scientic community and to my students a set of contributions of different kinds. I will try to make clear these contributions for the reader in the next two chapters (written in English and in French). This document is organized in the following way : Part II contains my complete curriculum vitae (in french) where all these contributions will be described in detail. Part III contains then the scientific contributions of the manuscript. What I aim in this chapter is to describe, but further, to analyze them with a distanced look and providing a critical view, announcing perspectives, and placing and discussing the obtained results in the societal context. This is in straight relation with item 4 above. Also, I prefer to adopt, as far as possible, a form comprehensible to the non-automatic control expert, with, as far as possible as well, qualitative explanations and then appropriated references containing the theorems and the definitions corresponding to the qualitative explanations will be provided. In the case it is necessary, they are provided within the text. The Part III is structured in the following chapters. Chapter 8 contains an overview of the global transportation scenario with the associated challenges and a description of the driving assistance systems context. Chapter 9 contains my scientific contributions. These include my research results, my contributions in students advising, in the coordination of research groups, and the collaborative works. It is structured in 3 sections : Section 9.1 introduces what will be the greed for a part of the main contributions, that are described in Sections 9.2 and 9.3. Section 9.1 is also dedicated to showing to the reader how theory and abstractions can be very important for solving real problems. Chapter 9.4 describes other contributions that are the result of collaborative works. A discussion from a multidisciplinary view is provided in Chapter 9.5 based on a survey paper of myself. Chapter 10 will be finally dedicated to the perspectives and the general conclusions. Then last Part contains as annexes a selection of the publications that I consider the most illustrative of my contributions described in Chapter 9. Finally, since the described work is in the intersection of two communities - the transportation and the control theory communities - I decided to write a part of the document dedicated to the non control experts readers. This is Part VI of the document whose aim is to provide some fundamental notions on control theory in a very simple qualitative description whose understanding will help the different readers to understand the contributions.

New Strategies to Improve Multilateration Systems in the Air Traffic Control

Scipedia content — Tue, 26 Jan 2021 13:16:12 +0100

Develop new strategies to design and operate the multilateration systems, used for air traffic control operations, in a more efficient way. The design strategies are based on the utilization of metaheuristic optimization techniques and they are intended to found the optimal spatial distribution of the system ground stations, taking into account the most relevant system operation parameters. The strategies to operate the systems are based on the development of new positioning methods which allow solving the problems of uncertainty position and poor accuracy that the current systems can present. The new strategies can be applied to design, deploy and operate the multilateration systems for airport surface surveillance as well as takeoff-landing, approach and enroute control. An important advance in the current knowledge of air traffic control is expected from the development of these strategies, because they solve several deficiencies that have been made clear, by the international scientific community, in the last years.

Analyse et diagnostic des défauts dans les chaînes de traction à MSAP pour les véhicules hybrides série

Scipedia content — Tue, 26 Jan 2021 13:12:26 +0100

The interest in the electric vehicles rose recently due both to environmental questions and to energetic dependence of the contemporary society. Accordingly, it is necessary to study and implement in these vehicle fault diagnosis systems which enable them to be more reliable and safe enhancing its sustainability. In this work after a review on problem of faults in the drivetrain of series hybrid electric vehicles (SHEV), a deep investigation on fault diagnosis of AC-DC power converter and permanent magnet synchronous motor (PMSM) have been done as two important parts of traction chains in SHEVs. In other major part of this work, four types of faults (stator winding inter turn short circuit, demagnetization, eccentricity ant bearing faults) of a PMSM have been studied. Inter turn short circuit of stator winding of PMSM in different speeds and loads has been considered to identify fault feature in all operation aspects, as it is expected by electric vehicle application. Experimental results aiming short circuits, bearing and eccentricity fault detection has been presented. Analytical and finite element method (FEM) aiming demagnetization fault investigation has been developed. The AC-DC converter switches are generally exposed to the possibility of outbreak open phase faults because of troubles of the switching devices. This work proposes a robust and efficient identification method for data acquisition selection aiming fault analysis and detection. Two new patterns under AC-DC converter failure are identified and presented. To achieve this goal, four different level of switches fault are considered on the basis of both simulation and experimental results. For accuracy needs of the identified pattern for SHEV application, several parameters have been considered namely: capacitor size changes, load and speed variations. On the basis of the developed fault sensitive models above, an ANN based fault detection, diagnosis strategy and the related algorithm have been developed to show the way of using the identified patterns in the supervision and the diagnosis of the PMSM drivetrain of SHEVs. ANN method have been used to develop three diagnosis based models for : the vector controlled PMSM under inter turn short circuit, the AC/DC power converter under an open phase fault and also the PMSM under unbalanced voltage caused by open phase DC/AC inverter. These models allow supervising the main components of the PMSM drivetrains used to propel the SHEV. The ANN advantages of ability to include a lot of data mad possible to classify the faults in terms of their type and severity. This allows estimating the performance degree of that drivetrains during faulty conditions through the parameter state of health (SOH). The latter can be used in a global control strategy of PMSM control in degraded mode in which the control is auto-adjusted when a defect occurs on the system. The goal is to ensure a continuity of service of the SHEV in faulty conditions to improve its reliability.; L'intérêt pour les véhicules électriques ne cesse de croitre au sein de la société contemporaine compte tenu de ses nombreuses interrogations sur l’environnement et la dépendance énergétique. Dans ce travail de thèse, nous essayons d’améliorer l’acceptabtabilité sociétale du véhicule électrique en essayant de faire avancer la recherche sur le diagnostique des défauts d’une chaine de traction électrique. Les résultats escomptés devraient permettre à terme d’améliorer la fiabilité et la durabilité de ces systèmes.Nous commençons par une revue des problèmes des défauts déjà apparus dans les véhicules hybrides séries qui disposent de l’architecture la plus proche du véhicule électrique. Une étude approfondie sur le diagnostic des défauts d’un convertisseur de puissance statique (AC-DC) ainsi que celle du moteur synchrone à aimants permanents est menée. Quatre types de défauts majeurs ont été répertoriés concernant le moteur (court-circuit au stator, démagnétisation, excentricité du rotor et défaut des roulements). Au niveau du convertisseur, nous avons considéré le défaut d’ouverture des interrupteurs. Afin d’être dans les mêmes conditions d’utilisation réelle, nous avons effectué des tests expérimentaux à vitesse et charge variables. Ce travail est basé aussi bien sur l’expérimentation que sur la modélisation. Comme par exemple, la méthode des éléments finis pour l’étude de la démagnétisation de la machine. De même, l’essai en court-circuit du stator du moteur en présence d’un contrôle vectoriel.Afin de réaliser un diagnostic en ligne des défauts, nous avons développé un modèle basé sur les réseaux de neurones. L’apprentissage de ce réseau de neurone a été effectué sur la base des résultats expérimentaux et de simulations, que nous avons réalisées. Le réseau de neurones est capable d'assimiler beaucoup de données. Ceci nous permet de classifier les défauts en termes de sévérité et de les localiser. Il permet ainsi d'évaluer le degré de performance de la chaine de traction électrique en ligne en présence des défauts et nous renseigner ainsi sur l'état de santé du système. Ces résultats devraient aboutir à l’élaboration d’une stratégie de contrôle tolérant aux défauts auto-reconfigurable pour prendre en compte les modes dégradés permettant une continuité de service du véhicule ce qui améliorera sa disponibilité.

Efficiency optimization of the transportation supply chain activity: the maritime option for Volkswagen Autoeuropa

Scipedia content — Tue, 26 Jan 2021 13:10:51 +0100

Field Lab of Entrepreneurial Innovative Ventures With the current pressures for companies to reduce their CO2 emissions levels and the worldwide competition more fierce than ever it becomes critical for companies to optimize their processes and improve supply chain efficiency. Develop solutions that could satisfy both these requirements is mandatory to improve and sustain today’s businesses. For Portuguese industries with high transportation costs the maritime option has become increasingly reliable, experiencing a huge structural and technological improvement in the past decades. This work project aims the study of maritime transportation feasibility for Volkswagen Autoeuropa company; it combines the strong theoretical background with a data analysis and multi-scenario assessment. The methodologies used were the billing analysis, at the beginning, then followed by a thorough analysis of transportation and inventory costs and volumes which led to a range of potential supplies to be transported by maritime. At the end the result was 3 possible routes which demonstrate after the analysis only one be a viable option. It was performed also a CO2 analysis, a risk analysis and consequent contingency plan in order to finalize a complete approach to this maritime project NSBE - UNL

Pipeline transport of liquids

Scipedia content — Mon, 25 Jan 2021 20:24:09 +0100