bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating time dependent O‐D trip tables during peak periods
Authors: Pulugurtha Srinivas S. , Nambisan Shashi S. 
Published: January 2010

AbstractIntelligent transportation systems (ITS) have been used to alleviate congestion problems arising due to demand during peak periods. The success of ITS strategies relies heavily on two factors: 1) the ability to accurately estimate the temporal and spatial distribution of travel demand on the transportation network during peak periods, and, 2) providing real‐time route guidance to users. This paper addresses the first factor. A model to estimate time dependent origin‐destination (O‐D) trip tables in urban areas during peak periods is proposed. The daily peak travel period is divided into several time slices to facilitate simulation and modeling. In urban areas, a majority of the trips during peak periods are work trips. For illustration purposes, only peak period work trips are considered in this paper. The proposed methodology is based on the arrival pattern of trips at a traffic analysis zone (TAZ) and the distribution of their travel times. The travel time matrix for the peak period, the O‐D trip table for the peak period, and the number of trips expected to arrive at each TAZ at different work start times are inputs to the model. The model outputs are O‐D trip tables for each time slice in the peak period. 1995 data for the Las Vegas metropolitan area are considered for testing and validating the model, and its application. The model is reasonably robust, but some lack of precision was observed. This is due to two possible reasons: 1) rounding‐off, and, 2) low ratio of total number of trips to total number of O‐D pair combinations. Hence, an attempt is made to study the effect of increasing this ratio on error estimates. The ratio is increased by multiplying each O‐D pair trip element with a scaling factor. Better estimates were obtained. Computational issues involved with the simulation and modeling process are discussed.
A bi‐level programming approach — Optimal transit fare under line capacity constraints
Authors: Zhou Jing , Lam William H. K. 
Published: January 2010

AbstractThe fare of a transit line is one of the important decision variables for transit network design. It has been advocated as an efficient means of coordinating the transit passenger flows and of alleviating congestion in the transit network. This paper shows how transit fare can be optimized so as to balance the passenger flow on the transit network and to reduce the overload delays of passengers at transit stops. A bi‐level programming method is developed to optimize the transit fare under line capacity constraints. The upper‐level problem seeks to minimize the total network travel time, while the lower‐level problem is a stochastic user equilibrium transit assignment model with line capacity constraints. A heuristic solution algorithm based on sensitivity analysis is proposed. Numerical example is used to illustrate the application of the proposed model and solution algorithm.
Bus routing strategies in a transit market: A case study of Hong Kong
Authors: Wang James J. , Po Karen 
Published: January 2010

AbstractConventionally, the objective of transit routing is often set either to minimize the total operational cost, subject to a given level of service quality, or to maximize the service quality at a given acceptable cost. In a deregulated, commercial‐based environment however, such as bus and railway operations in cities of the UK and Hong Kong where several private firms compete in route‐based or area‐based market, routing becomes one of the means for higher returns rather than just for cost saving. In such a case, how do the transit providers set up their routes for profit‐maximization? Will the routing based on the provider's objective meet the user's objective? How do government regulations and policies affect the choice of transit provider's routing strategy?To answer these questions, we first examine the relationship between the objectives of users and transit providers, set up criteria for transit routing quality, and then investigate the possible routing configurations/patterns for a hypothetical case. These criteria include (1) the load factor of transit, (2) the level of route directness, (3) the level of route overlapping, and (4) the total number of routes and (5) the average of route length. These measures are finally applied to a real case in Hong Kong to examine the route changes of Kowloon Motor Bus from 1975 to 1995. The result of the empirical case reveais how key measures such as load factor are controlled by the bus operator and affected by government policies and how the bus routing pattern was adjusted to meet users' need. Facing the dilemma as evident in Hong Kong between the route directness and the efficiency of road use, we suggest that a rational multi‐modal routing structure be put in place if an institutional solution is introduced so that bus and other transit modes can form a sharing program or an alliance.
Simulation‐based estimates of delays at freeway work zones
Authors: Chien Steven I‐Jy , Goulias Dimitrios G. , Yahalom Shmuel , Chowdhury Shoaib M. 
Published: January 2010

AbstractWork zone related traffic delay is an important cost component on freeways with maintenance activities. This study demonstrates that delays may be underestimated by using the deterministic queuing theory. Computer simulation is a valuable approach of estimating delay under a variety of existing and future conditions. However, a single simulation run, which can be quite costly in terms of both computer and analyst time, produces a delay estimate for only one traffic level under one set of conditions. A method is developed in this paper to approximate delays by integrating limited simulation data, obtained from CORSIM and the concept of deterministic queuing theory, while various geometric conditions and time‐varying traffic distribution are considered. A calibrated and validated simulation model that can reflect work zone traffic operations on a segment of Interstate 1–80 in New Jersey is used to generate data for developing the proposed model. The comparison of delays estimated by the deterministic queuing model and the proposed model is conducted, while factors affecting the accuracy of the delay estimates are discussed.
Design and shared use of a terminal departure lounge for new large aircraft operations
Authors: de Barros Alexandre G. , Wirasinghe S. C. 
Published: January 2010

AbstractNew Large Aircraft (NLA) are new aircraft developments larger than any existing aircraft. The NLA's higher seat capacity will significantly impact passenger terminal design and operations. This paper focuses on the issues regarding the departure lounge. Deterministic queuing theory is used to determine the size and seating configuration of the lounge, as well as to decide whether a second level should be built to accommodate the increase in the number of passengers. The paper also discusses the use of the satellite section of a pier‐satellite terminal as a single lounge for the NLA. Spreadsheets are used to implement the analyses.
Power unit ‐ Cargo space link in inland waterway navigation
Authors: Radmilovic Zoran , Hrle Zlatko , Muskatirovic Jasna 
Published: January 2010

AbstractThis paper deals with transportation technology regarding links between power unit or motor ship and ship cargo space. These links can be divided into two groups: rigid and flexible. Rigid link, established between power unit and cargo space, is dominant in maritime and road transport (sea ships and trucks), and occasionally in transport on inland waterways (self‐propelled barges). Flexible link is used in railroad transport (between the locomotive and railroad units), partially in road transport (systems with trailers and semitrailers), and in inland waterway transport (push‐towing, pulling systems and combinations of these systems).The main goal of this research is determination of possible link types and organization of fleet for transport on inland waterways in case of flexible link.
Fuel consumption model for bus rapid transit
Authors: Zargari Shahriar A. , Khan Ata M. 
Published: January 2010

AbstractTransportation planners and policy analysts require, for scenario testing, a detailed fuel consumption model of public transit operating in multimodal corridors. Although much effort has been devoted to the development of detailed methodology for estimating fuel consumption of automobile travel on freeways and arterials, the same is not the case for public transit. This paper presents methodology for the estimation of fuel consumption for bus operation on transitways/busways serving major travel corridors. Bus fuel consumption model is reported for standard and articulated buses. This model was adapted from an existing heavy vehicle fuel use model by incorporating the transitway design and bus operational characteristics.
A fuzzy method for predicting the demand for rail freight transportation
Authors: Wong W. G. , Niu H. , Ferreira L. 
Published: January 2010

AbstractThe demand for rail freight transportation is a continuously changing process over space and time and is affected by many quantitative and qualitative factors. In order to develop a more rational transport planning process to be followed by railway organizations, there is a need to accurately forecast freight demand under a dynamic and uncertain environment. In conventional linear regression analysis, the deviations between the observed and the estimated values are supposed to be due to observation errors. In this paper, taking a different perspective, these deviations are regarded as the fuzziness of the system's structure. The details of fuzzy linear regression method are put forward and discussed in the paper. Based on an analyzes of the characteristics of the rail transportation problem, the proposed model was successfully applied to a real example from China. The results of that application are also presented here.
Evaluation of actuated control of diamond interchanges with advanced experimental design
Authors: Lee Sangsoo , Messer Carroll J. 
Published: January 2010

AbstractTwo three‐phase actuated control strategies at diamond interchanges were investigated for different ramp spacings and traffic patterns. An advanced experimental design, hardware‐in‐the‐loop control, was employed for the simulation study. Operational performance was identified in terms of cycle length, average delay and total stops.Experimental results showed that the two phasing strategies gave similar performance in terms of cycle length and average delay, but not stops. The cycle length of three‐phase operation increased slightly as the ramp spacing became wider. The delay of each strategy was dependent on the traffic pattern, but there was a distinct movement preference for each strategy. The total stops decreased as the spacing increased, and it was the most sensitive variable for the studied traffic demand level. It was also shown that the concept of the hardware‐in‐the‐loop control provides an effective way to evaluate the signal phasing and control strategies.
Retrospect and prospect of public transit privatization in China
Authors: Chen Xueming 
Published: January 2010

AbstractAs the most populous country in the world with a heavy reliance on public transit, China's public transit privatization has a global significance. China's post‐Mao economic reform and establishment of market‐oriented economy have stimulated its public transit privatization at a very fast pace. The largest Chinese cities have been spearheading the implementation of different privatization measures, such as granting franchises, company merger, company reorganization, public/private partnership, responsibility systems, and many others. All these privatization efforts have yielded preliminary successful results, even though some obstacles are encountered. In the future, new privatization‐related laws are expected to be enacted, government functions and business functions would be further separated, privatizing other public transit services besides operation would take place, and some negative impacts associated with privatization would be mitigated.
Validation of a schedule‐based capacity restraint transit assignment model for a large‐scale network
Authors: Poon M. H. , Tong C. O. , Wong S. C. 
Published: January 2010

AbstractThis paper describes the application of a capacity restraint trip assignment algorithm to a real, large‐scale transit network and the validation of the results. Unlike the conventional frequency‐based approach, the network formulation of the proposed model is dynamic and schedule‐based. Transit vehicles are assumed to operate to a set of pre‐determined schedules. Passengers are assumed to select paths based on a generalized cost function including in‐vehicle and out‐of‐vehicle time and line change penalty. The time‐varying passenger demand is loaded onto the network by a time increment simulation method, which ensures that the capacity restraint of each vehicle during passenger boarding is strictly observed. The optimal‐path and path‐loading algorithms are applied iteratively by the method of successive averages until the network converges to the predictive dynamic user equilibrium. The Hong Kong Mass Transit Railway network is used to validate the model results. The potential applications of the model are also discussed.
The development and implementation of the operation system and data bank for the intelligent transportation system — sitcuo
Authors: Weigang Li , Yamashita Yaeko , Koendjbiharie Marlon Winston , de Moura Jucá Ricardo Cezar , Maciver Andrew 
Published: January 2010

AbstractSITCUO (Sistemas de Informações de Transportes Coletivos Urbanos por Õnibus) ‐ a dynamic information system for urban bus passengers in Brasilia, using business intelligence, was developed to optimize bus operations and increase the satisfaction of urban transportation users. In order to achieve these objectives the system involves the convergence of a number of different technologies, including: Global Positioning System (GPS), Geographic Information System (GIS), database, data mining, Internet and telecommunications. The system includes communication between the GPS, the database, the Control Centre and the user interfaces, which provide estimated bus arrival times via the information display panels and the Internet. The information system at the Control Centre was implemented by applying Java, JavaServer Pages (JSP), and a Relational Database Management System (RDBMS) using an object‐oriented approach. The paper will present the general description of the system, the algorithms for estimating the arrival time of the bus at the bus stop, the implementation procedure adopted, the results of experiments undertaken on a bus route in Brasilia and the conclusions.
Multimodal traveling and its impact on urban transit network design
Authors: van Nes Rob , Bovy Piet H. L. 
Published: January 2010

AbstractMultimodal trip making, that is trips using a combination of several modes between origin and destination, is expected to be beneficial to society and might offer advantages to the traveler as well. This article looks at some of the implications of multi‐modality in trip making for the design of urban transit systems since these play an important role in multi‐modal transportation systems. In this respect, the article looks at the strategic design characteristics of urban transit networks, that is line density, stop density and service frequencies for the case of multimodal access to urban transit networks and for hierarchical network structures in urban transit systems. The analyses show that multimodal access does not require alternative network structures. For hierarchical network structures it is concluded that these are primarily determined by the hierarchy in demand densities and thus by hierarchy in urban structures.
Scheduling considerations for a branching transit route
Authors: Sun Aichong , Hickman Mark 
Published: January 2010

AbstractThis paper addresses the impacts of different scheduling alternatives for a branching transit route. It examines different schedule alternatives that might be used to optimize the route performance in terms of the passenger traveling time distributed among branch passengers and trunk‐line passengers. The schedule alternatives considered include transit vehicle allocation to different branches, offset shifting across vehicles on different branches, and vehicle holding (slack time) in the transit vehicle schedule. With these variables, several vehicle schedules are devised and examined based on a wide variety of possible passenger boarding scenarios using deterministic service models. Test outcomes provide general conclusions about the performance of the strategies. Vehicle assignment leading to even headways among branches is generally preferred for the case of low passenger demand. However, when passenger demand is high, or the differences between the passenger demands on branches are significant, unequal vehicle assignment will be helpful to improve the overall route performance. Holding, as a proactive strategy in scheduling, has the potential to be embedded into the schedule as a type of slack time, but needs further evidence and study to determine the full set of conditions where it may be beneficial. Offset shifting does not show sufficient evidence to be an efficient strategy to improve route performance in the case of low or high passenger demand.
Interspecific resources: a major tool for quantitative trait locus cloning and speciation research
Authors: L'Hôte David , Laissue Paul , Serres Catherine , Montagutelli Xavier , Veitia Reiner A. , Vaiman Daniel 
Published: January 2010

AbstractPositional cloning of the quantitative trait locus (QTL) still encounters numerous difficulties, which explains why thousands of QTL have been mapped, while only a few have been identified at the molecular level. Here, we focus on a specific mapping tool that exists in plant and animal model species: interspecific recombinant congenic strains (IRCSs) or interspecific nearly isogenic lines (NILs). Such panels exhibit a much higher sequence diversity than intraspecific sets, thus enhancing the contrasts between phenotypes. In animals, it allows statistical significance to be reached even when using a limited number of individuals. Therefore, we argue that interspecific resources may constitute a major genetic tool for positional cloning and for understanding some bases of speciation mechanisms.
Generation of branched actin networks: assembly and regulation of the N‐WASP and WAVE molecular machines
Authors: Derivery Emmanuel , Gautreau Alexis 
Published: January 2010

AbstractThe Arp2/3 complex is a molecular machine that generates branched actin networks responsible for membrane remodeling during cell migration, endocytosis, and other morphogenetic events. This machine requires activators, which themselves are multiprotein complexes. This review focuses on recent advances concerning the assembly of stable complexes containing the most‐studied activators, N‐WASP and WAVE proteins, and the level of regulation that is provided by these complexes. N‐WASP is the paradigmatic auto‐inhibited protein, which is activated by a conformational opening. Even though this regulation has been successfully reconstituted in vitro with isolated N‐WASP, the native dimeric complex with a WIP family protein has unique additional properties. WAVE proteins are part of a pentameric complex, whose basal state and activated state when bound to the Rac GTPase were recently clarified. Moreover, this review attempts to put together diverse observations concerning the WAVE complex in the conceptual frame of an in vivo assembly pathway that has gained support from the recent identification of a precursor.
The dynamic replicon: adapting to a changing cellular environment
Authors: Herrick John 
Published: January 2010

AbstractEukaryotic cells are often exposed to fluctuations in growth conditions as well as endogenous and exogenous stress‐related agents. During development, global patterns of gene transcription change substantially, and these changes are associated with altered patterns of DNA replication and larger distances between replication origins in somatic cells compared to embryos. Conversely, when cells experience difficulties while replicating DNA, the replication program is dramatically altered and distances between replication origins decrease. Recent evidence indicates that each unit of replication, or replicon, can correspond to one or more potential replication origins, but in the case of multiple potential origins, only one is selected to initiate replication of the replicon. How one origin is selected from multiple potential origins and how origin densities are regulated during genome duplication remains unclear. The following review addresses some of the mechanisms involved in regulating replication origins during both a normal and perturbed eukaryotic cell cycle.
Elastin‐like polypeptides: Biomedical applications of tunable biopolymers
Authors: MacEwan Sarah R. , Chilkoti Ashutosh 
Published: January 2010

AbstractArtificial repetitive polypeptides have grown in popularity as a bioinspired alternative to synthetic polymers. The genetically encoded synthesis, monodispersity, potential lack of toxicity, and biocompatibility are attractive features of these biopolymers for biological applications. Elastin‐like polypeptides (ELPs) are one such class of biopolymers that are of particular interest because of their “smart”—stimuli responsive—properties. Herein, we discuss the genetically encoded design and recombinant synthesis of ELPs that enable precise control of their physicochemical properties and which have led to a wide range of biomedical applications of these biopolymers in the last decade. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94:60–77, 2010.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Domain swapping in materials design
Authors: Nagarkar Radhika P. , Hule Rohan A. , Pochan Darrin J. , Schneider Joel P. 
Published: January 2010

AbstractPeptide self‐assembly can be used as a bottom–up approach to material fabrication. Although many different types of materials can be prepared from peptides, hydrogels are perhaps one of the most common. Gels typically result from the self‐assembly of peptides into fibrillar networks. Controlling the structural morphology of these fibrils and the networks they form allows direct control over a given material's bulk properties. However, exerting this control is extremely difficult as the mechanistic rules that govern peptide self‐assembly are far from being established. Conversely, several amyloidogenic proteins have been shown to self‐assemble into fibrils using a mechanism known as domain swapping. Here, discrete units of secondary structure or even whole domains are exchanged (swapped) among discrete proteins during self‐assembly to form extended networks with precise structural control. This review discusses several common mechanistic variations of domain swapping using naturally occurring proteins as examples. The possibility of using these principles to design peptides capable of controlled assembly and fibril formation leading to materials with targeted properties is explored. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 141–155, 2010.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com