bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating critical lines and stations considering the impact of the consequence using transit assignment model ‐case study of London's underground network
Authors: Shimamoto Hiroshi , Kurauchi Fumitaka , Schmöcker Jan‐Dirk , Bell Michael G H 
Published: January 2010

AbstractAs the problem of full transit vehicles is encountered daily by passengers in most of the big cities, previous research evaluated the consequence of overcrowding in terms of on‐board crowding and passengers not being able to board with full vehicles. The impact of overcrowding in the real world is, however, not necessarily proportional to these numbers. This paper attempts to specify the critical lines and stations of a network by considering the number of passengers failing to board and attempting to evaluate its impact on service quality and safety risks. The hypothesis is that larger stations with wider platforms can often cope better with overcrowding than smaller stations. Therefore a station size dependent satisfaction function is proposed, which takes values from 0 to 1. The method is applied to London's underground network with a number of scenarios which show critical stations in the network if delays occur.
Network reliability‐based optimal toll design
Authors: Li Hao , Bliemer Michiel C. J. , Bovy Piet H. L. 
Published: January 2010

AbstractOptimal toll design from a network reliability point of view is addressed in this paper. Improving network reliability is proposed as a policy objective of road pricing. A reliability‐based optimal toll design model, where on the upper level network performance including travel time reliability is optimized, while on the lower level a dynamic user‐equilibrium is achieved, is presented. Road authorities aim to optimize network travel time reliability by setting tolls in a network design problem. Travelers are influenced by these tolls and make route and trip decisions by considering travel times and tolls. Network performance reliability is analyzed for a degradable network with elastic and fluctuated travel demand, which integrates reliability and uncertainty, dynamic network equilibrium models, and Monte Carlo methods. The proposed model is applied to a small hypothesized network for which optimal tolls are derived. The network travel time reliability is indeed improved after implementing optimal tolling system. Trips may have a somewhat higher, but more reliable, travel time.
An analysis of instability in a departure time choice problem
Authors: Iryo Takamasa 
Published: January 2010

AbstractThis study performs a theoretical analysis of instability in a departure time choice problem. Stability of equilibrium is an important factor for reliability of travel time. If equilibrium is not stable, travel time changes over a period of days even if demand and network performance are stable. This study examines the stability of a dynamic user equilibrium problem by using the departure time choice problem. The mechanism of day‐to‐day changes in a traveller's behaviour is determined first, and then a function that indicates dissimilarity to equilibrium is defined. The day‐to‐day changes in the dissimilarity function are mathematically examined using approximations. A numerical test is also carried out to verify the result. Results of these analyses show that there can be a case where the system does not converge to equilibrium. It is also indicated that this instability should be caused by the non‐monotonicity of the schedule cost.
Heterogeneous traffic flow modelling for an arterial using grid based approach
Authors: Gundaliya P. J. , Mathew Tom V. , Dhingra S. L. 
Published: January 2010

AbstractA grid based modelling approach akin to cellular automata (CA) is adopted for heterogeneous traffic flow simulation. The road space is divided into a grid of equally sized cells. Moreover, each vehicle type occupies one or more cell as per its size unlike CA traffic flow model where each vehicle is represented by a single cell. Model needs inputs such as vehicle size, its maximum speed, acceleration, deceleration, probability constants, and arrival pattern. The position and speed of the vehicles are assumed to be discrete. The speed of each vehicle changes according to its interactions with other vehicles, following some stochastic rules depending on the circumstances. The model is calibrated and validated using real data and VISSIM. The results indicate that grid based model can reasonably well simulate complex heterogeneous traffic as well as offers higher computational efficiency needed for real time application.
Private road competition and equilibrium with traffic equilibrium constraints
Authors: Yang Hai , Xiao Feng , Huang Haijun 
Published: January 2010

AbstractToll road competition is one of the important issues under a build‐operate‐transfer (BOT) scheme, which is being encountered nowadays in many cities. When there are two or more competing firms and each firm operates a competitive toll road, their profits are interrelated due to the competitors' choices and demand inter‐dependence in the network. In this paper we develop game‐theoretic approaches to the study of the road network, on which multiple toll roads are operated by competitive private firms. The strategic interactions and market equilibria among the private firms are analyzed both in determining their supply (road capacity) and price (toll level) over the network. The toll road competition problems in general traffic equilibrium networks are formulated as an equilibrium program with equilibrium constraints or bi‐level variational inequalities. Heuristic solution methods are proposed and their convergences are demonstrated with simple network examples. It is shown that private pricing and competition can be both profitable and welfare‐improving.
Lane change algorithm for autonomous vehicles via virtual curvature method
Authors: Ho M. L. , Chan P. T. , Rad A. B. 
Published: January 2010

AbstractThis paper addresses the lane changing problem of autonomous vehicles when there is no road infrastructure support. The autonomous vehicle should drive from the current lane to the adjacent lane in the absence of a reference path to guide the vehicle to the new lane. We suggest an algorithm that incorporates a virtual road curvature with bicycle model for lane change guidance. As the name suggests, the virtual road curvature does not physically exist. It is a user assigned radius of a curved path which connects the current lane to the adjacent lane. Since the lateral sensor readings during lane changing maneuver are erroneous, the steering angle along with the virtual curvature is fed into a bicycle model to estimate the lateral position during the transition to the next lane. Details of the algorithm and the virtual road curvature determination are presented in the paper. In contrast to other lane changing methods, controller switching is not required and the same controller is for both lane keeping and lane changing. The algorithm is verified experimentally and the results are comparable with lane changing with physical transition lane.
Decision support for simulating the car park activity in an urban area
Authors: Boussier Jean‐Marie , Sarramia David , Estraillier Pascal 
Published: January 2010

AbstractComplexity of car park activity is reproduced from a concurrent execution of behaviour of various drivers. This paper presents a step in the development of a multimodal traffic simulator based on multi‐agent paradigm and designed as a decision aid tool as well as a video game. The user‐player has the opportunity to test different scenarios. We propose an approach for designing the decision‐making rules and the learning mechanism for a car driver agent. For that, a panel of methods such as stated preference modelling, Design Of Experiments and data fusion is used. Initial behavioural models, based on similar preferences, are developed for specified categories. Each agent will adapt its behaviour after executing its learning process. Our approach can be used in order to optimize needs of road network users and those of people in charge of traffic regulation. A demonstrator has been developed to test parking policies in an urban area as well as changes of car park characteristics.
The multi‐actor, multi‐criteria analysis methodology (MAMCA) for the evaluation of transport projects: Theory and practice
Authors: Macharis Cathy , de Witte Astrid , Ampe Jeroen 
Published: January 2010

AbstractIn this paper the multi‐actor multi‐criteria analysis (MAMCA) method to evaluate transport projects is presented. This evaluation method specifically focuses on the inclusion of qualitative as well as quantitative criteria with their relative importance, defined by the multiple stakeholders, into one comprehensive evaluation process in order to facilitate the decision making process by the different stakeholders. The MAMCA methodology is introduced by an overview of other evaluation methods for transport projects in the past and is illustrated by means of two practical cases. The introduction will lead us to the theoretical conception of the MAMCA method where we draw the attention to the proven usefulness of the MAMCA for the evaluation of transport projects and the inclusion of different kinds of stakeholders, individuals as well as groups, into the evaluation process.
An investigation of incident frequency, duration and lanes blockage for determining traffic delay
Authors: Qi Yi (Grace) , Teng Hualiang (Harry) , Martinelli David R. 
Published: January 2010

AbstractTraffic delay caused by incidents is closely related to three variables: incident frequency, incident duration, and the number of lanes blocked by an incident that is directly related to the bottleneck capacity. Relatively, incident duration has been more extensively studied than incident frequency and the number of lanes blocked in an incident. In this study, we provide an investigation of the influencing factors for all of these three variables based on an incident data set that was collected in New York City (NYC). The information about the incidents derived from the identification can be used by incident management agencies in NYC for strategic policy decision making and daily incident management and traffic operation.In identifying the influencing factors for incident frequency, a set of models, including Poisson and Negative Binomial regression models and their zero‐inflated models, were considered. An appropriate model was determined based on a model decision‐making tree. The influencing factors for incident duration were identified based on hazard‐based models where Exponential, Weibull, Log‐logistic, and Log‐normal distributions were considered for incident duration. For the number of lanes blocked in an incident, the identification of the influencing factors was based on an Ordered Probit model which can better capture the order inherent in the number of lanes blocked in an incident. As identified in this study, rain is the only factor that significantly influenced incident frequency. For incident duration and the number of lanes blocked in an incident, various factors had significant impact. As concluded in this study, there is a strong need to identify the influencing factors in terms of different types of incidents and the roadways where the incidents occured.
Airport obstacle surfaces
Authors: Litsheim Scott , Xiao Xiaosong 
Published: January 2010

AbstractThe most commonly used criteria to determine complicated airport obstacle surfaces are FAR Part 77 imaginary surfaces, TERPS, and the one engine inoperative obstacle identification surface for air carriers. For each obstacle surface there are tradeoffs encountered in our practice between the obstruction penetration and extension of runway, change of flight profile, and allowable aircraft maximum payloads. For the purposes of both airport engineering and airport planning, a better understanding of these different obstacle surfaces and their application is important. In this paper, the differences and relationships between these surfaces are addressed. The conditions for the use of each criterion are discussed. In addition, the FAA's Obstruction Evaluation / Airport Airspace Analysis (OE/AAA) process is reviewed.
A two‐leveled multi‐objective symbiotic evolutionary algorithm for the hub and spoke location problem
Authors: Shin Kyoung Seok , Kim Jun Hyuk , Kim Yeo Keun 
Published: January 2010

AbstractWe consider a hub and spoke location problem (HSLP) with multiple scenarios. The HSLP consists of four subproblems: hub location, spoke location, spoke allocation, and customer allocation Under multiple scenarios, we aim to provide a set of well‐distributed solutions, close to the true Pareto optimal solutions, for decision makers. We present a novel multi‐objective symbiotic evolutionary algorithm to solve the HSLP under multiple scenarios. The algorithm is modeled as a two‐leveled structure, which we call the two‐leveled multi‐objective symbiotic evolutionary algorithm (TMSEA). In TMSEA, two main processes imitating symbiotic evolution and endosymbiotic evolution are introduced to promote the diversity and convergence of solutions. The evolutionary components suitable for each sub‐problem are defined. TMSEA is tested on a variety of test‐bed problems and compared with existing multi‐objective evolutionary algorithms. The experimental results show that TMSEA is promising in solution convergence and diversity.
The development of taiwan arterial traffic‐adaptive signal control system and its field test: A taiwan experience
Authors: Wu Yueh‐Tzu , Ho Chi‐Hong 
Published: January 2010

AbstractThis Taiwan traffic‐adaptive arterial signal control model borrowed its traffic flow framework mainly from a British traffic‐adaptive control model with a cyclic traffic progression function, i.e. SCOOT (Split Cycle Office Optimisation Technique). The new arterial control model can take into account delays of both major and minor streets and make real‐time signal timing decisions with optimal two‐way signal offsets, so as to create the best arterial signal operation performance. It has been developed to be an online real‐time software for both simulation testing and field validation. Through simulation, it was found that the performance when operating this newly developed real‐time arterial traffic‐adaptive model was significantly better than when using the optimal fixed‐time arterial timing plan. On the aspect of field testing, three signalized intersections located in East District, Tainan City, Taiwan were selected to be the test sites. Fairly good traffic control performance has been demonstrated in that it can effectively reduce travel delays of the control arterial as a whole. Additional discussions about how to combine travel delay and the total number of vehicle stops into a new control performance index have also been included to make the new traffic‐adaptive model more flexible and reasonable to meet the expectations of different driver groups in the arterial system.
Multi‐objective highway alignment optimization using a genetic algorithm
Authors: Maji Avijit , Jha Manoj K. 
Published: January 2010

AbstractThe available highway alignment optimization algorithms use the total cost as the objective function. This is a single objective optimization process. In this process, travel‐time, vehicle operation accident earthwork land acquisition and pavement construction costs are the basic components of the total cost. This single objective highway alignment optimization process has limited capability in handling the cost components separately. Moreover, this process cannot yield a set of alternative solutions from a single run. This paper presents a multi‐objective approach to overcome these shortcomings. Some of the cost components of highway alignments are conflicting in nature. Minimizing some of them will yield a straighter alignment; whereas, minimizing others would make the alignment circuitous. Therefore, the goal of the multiobjective optimization approach is to handle the trade‐off amongst the highway alignment design objectives and present a set of near optimal solutions. The highway alignment objectives, i.e., cost functions, are not continuous in nature. Hence, a special genetic algorithm based multi‐objective optimization algorithm is suggested The proposed methodology is demonstrated via a case study at the end.
Lottery attractiveness and presentation mode of probability and value information
Authors: Fiedler Klaus , Unkelbach Christian 
Published: January 2010

AbstractThe attractiveness of lotteries that vary in p (probability) and o (outcome) depends on the presentation mode of p and o information. Extending previous findings on temporally experienced p, we manipulate the numerically stated versus spatially experienced format of both p (graphical presentation of a distribution of lottery tickets in an urn) and o (distribution of money notes). Lottery attractiveness ratings were sensitive to the expected value (EV), but p received more weight than o at constant EV levels (p‐dominance). Both EV sensitivity and p‐dominance were enhanced for experienced p and numerical o. This format particularly revealed the unattractiveness of low‐p lotteries. Experiencing p was functional in terms of accuracy and high‐risk avoidance, but only when the task environments rendered p diagnostic of EV. The presentation mode manipulations did not affect the initial perception stage but the relative weighting of p and o in the final judgment integration stage. Copyright © 2010 John Wiley & Sons, Ltd.
Congenital malformations in infants born after in vitro fertilization in Sweden
Authors: Källén Bengt , Finnström Orvar , Lindam Anna , Nilsson Emma , Nygren Karl‐Gösta , Otterblad Petra Olausson 
Published: January 2010

AbstractBACKGROUND:The risk for congenital malformations is increased in infants born after in vitro fertilization (IVF). Some specific malformations appear to be more affected than others.METHODS:The presence of congenital malformations in 15,570 infants born after IVF with an embryo transfer between April 1, 2001, and the end of 2006 were compared with all infants born in Sweden during 2001 to 2007 (n = 689,157). Risk estimates were made after adjusting for year of birth, maternal age, parity, smoking, and body mass index. The risks of specific malformations were compared with data from a previous study (1982 to March 31, 2001) of 16,280 infants born after IVF. Different IVF methods were compared to respect to malformation risk.RESULTS:Increased risks of a similar magnitude were found for most cardiovascular malformations and limb reduction defects for both study periods. For neural tube defects, cardiac septal defects, and esophageal atresia, there was still an increased risk, but it was lower during the second than during the first period. For small bowel atresia, anal atresia, and hypospadias, the risk increase observed during the first study period had disappeared during the second period. An increased risk was seen for some syndromes that have been associated with imprinting errors. No difference in malformation risk according to IVF method was apparent.CONCLUSIONS:A slightly increased risk for congenital malformations after IVF persists. A decreasing risk is seen for some specific malformations, either true or the result of multiple testing. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Periconceptional nutrient intakes and risks of conotruncal heart defects
Authors: Shaw Gary M. , Carmichael Suzan L. , Yang Wei , Lammer Edward J. 
Published: January 2010

AbstractBACKGROUNDFew inquiries into periconceptional nutrition, other than folate, and risk of heart defects exist. We investigated the observed association between conotruncal heart defects and periconceptional vitamin use, as well as potential associations with other dietary nutrients.METHODSData derived from a population‐based, case‐control study of fetuses and liveborn infants among California births between July 1999 and June 2004; 76% of eligible case mothers and 77% of eligible control mothers were interviewed. Cases included 140 with d‐transposition of great arteries (dTGA), and 163 with tetralogy of Fallot (TOF). Total number of controls was 698. Use of vitamins was elicited by questionnaire for the periconceptional period. Dietary nutrient intake was elicited by a well‐known food frequency questionnaire.RESULTSThe odds ratio for dTGA associated with supplemental vitamin use was 1.0 (95% confidence interval [CI], 0.7–1.5) and for TOF was 0.9 (95% CI, 0.6–1.3). We observed increased risks associated with lower dietary intakes of linoleic acid, total carbohydrate, and fructose for dTGA, whereas decreased risks were observed for lower intakes of total protein and methionine for TOF. Lower dietary intake of several micronutrients—namely folate, niacin, riboflavin, and vitamins B12, A, and E, even after simultaneous adjustment for other studied nutrients—was associated with increased risk of dTGA but not TOF. These associations were observed among women who did not use vitamin supplements periconceptionally. Analytic consideration of several potential confounders did not reveal alternative interpretations of the results.CONCLUSIONEvidence continues to accumulate to show that nutrients, particularly folate, influence risks of structural birth defects. Our results extend observations that other nutrients may also be important in heart development. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
An efficient computational approach for prior sensitivity analysis and cross‐validation
Authors: Bornn Luke , Doucet Arnaud , Gottardo Raphael 
Published: January 2010

AbstractPrior sensitivity analysis and cross‐validation are important tools in Bayesian statistics. However, due to the computational expense of implementing existing methods, these techniques are rarely used. In this paper, the authors show how it is possible to use sequential Monte Carlo methods to create an efficient and automated algorithm to perform these tasks. They apply the algorithm to the computation of regularization path plots and to assess the sensitivity of the tuning parameter ing‐prior model selection. They then demonstrate the algorithm in a cross‐validation context and use it to select the shrinkage parameter in Bayesian regression. The Canadian Journal of Statistics 38:47–64; 2010 © 2010 Statistical Society of Canada