bluuebunny/crossref_metadata_2025_split huggingface dataset:
Designing personal rapid transit (PRT) networks
Authors: Ma Jun , Schneider J. B. 
Published: January 2010

AbstractThis paper presents a heuristic method for designing a PRT network. Because the PRT system operating characteristics and performance measures differ widely from those of conventional transit technologies, an algorithm for the PRT network design problem (NDP) is derived by using concepts from some current NDP algorithms. We minimize the sum of passenger travel time cost, construction cost, vehicle cost and operational costs, subject to an available budget of guideway, a maximum number of vehicles and given link capacities. Starting with a well‐connected initial network, the algorithm eliminates and adds links iteratively as it searches for a near‐optimal solution. If this solution satisfies the budget constraint, it is considered to be acceptable. Otherwise, additional links are deleted until a feasible near‐optimal solution is obtained. The link elimination phase of the algorithm only considers half of the links at a time which greatly decreases computing time. None of the links in an acceptable solution will be overloaded.
Optimal slack time for timed transfers at a transit terminal
Authors: Lee Kurt K. T. , Schonfeld Paul 
Published: January 2010

AbstractAt transit terminals where two routes interchange passengers, total system costs may be reduced by allowing some “slack” time in the vehicle schedules to decrease the probability of missed connections. Transfer cost functions are formulated and used to determine optimal slack time for simple systems with transfers between one bus route and one rail line. Some analytic results are derived for empirical discrete and Gumbel distributions of bus arrival times. Relations between the optimal slack times and headways, transfer volumes, passenger time values, bus operating costs, and standard deviations of bus and train arrivals are also developed numerically using normally distributed arrivals. However, the proposed numerical approach can optimize slack times for any observed arrival distributions. The results provide some guidelines on desirable slack times and show that schedule coordination between the two routes is not worth attempting when standard deviations of arrivals exceed certain levels. Possible extensions of this work are suggested in the last section.
A pre‐appraisal model for rail transit in developing cities
Authors: Bamford T. J. G. , Allport R. J. 
Published: January 2010

AbstractA major research study funded by the UK Overseas Development Administration (ODA) and designed to establish the necessary considerations for viability of mass rapid transit railways in developing cities was recently completed. The analytical core of the study was a pre‐appraisal model, which combines an innovative strategic land use/transport model utilizing relationships from developing cities and an economic evaluation model. This model — MRTAP — has now been developed into a user‐friendly package which the ODA intend should be made widely available in the developing world. The paper describes the basis of this model.
Aircraft and maintenance scheduling support, mathematical insights and a proposed interactive system
Authors: Biró M. , Simon I. , Tánczos C. 
Published: January 2010

AbstractIn this paper we first review the current practice of operative aircraft and maintenance scheduling at the Hungarian Airlines. The ideas to be included in the proposed operative scheduling support system mean new contributions from both the algorithmic and human‐computer interaction points of view. The algorithm is based on new graph theoretical results which were motivated by the necessity of combining a given flight schedule with the strict maintenance requirements of the aircraft. Aircraft rotation corresponds in mathematical terms to the coloring of an interval graph with colors representing the tail numbers in such a way that the vertices corresponding to maintenance checks are colored in advance. The human‐computer interface is built on the Microsoft Windows graphics environment, which allows a simultaneous, visual and active contact with all necessary information and methods.
Dependability as a measure of on‐time performance of personal rapid transit systems
Authors: Anderson J. Edward 
Published: January 2010

AbstractA comprehensive method for calculating and measuring Dependability of Personal Rapid Transit systems is derived and compared with the more common measure called Availability. Availability is the percentage of all revenue trips that are completed without interruption. It does not take into account the duration of delays of the passengers because of the diffiiculty of gathering the necessary information in conventional transit systems. In PRT systems, vehicle‐hours of travel and of delay relate in a statistically simple way to person‐hours of travel and of delay. Therefore, in such systems, it is practical to use the performance measure called Dependability that takes into account the inconveince of people as a result of delays. To form a bridge to present practice, it is recommended that both measures be calculated and compared in forthcoming PRT systems. With today's computer systems, this is easily accomplished.
Evaluation of truck configurations based on structural performance of bridges
Authors: Fu C. C. , Schelling David R. , Ayyub Bilal M. 
Published: January 2010

AbstractContained herein are the results of research which quantifies the effects that various existing and projected truck configurations have as live loadings upon bridges which currently exist on the National Bridge Inventory (NBI). The truck configurations were determined from those actual or proposed vehicles which exhibit the highest GVW and which either are causing or are perceived to cause the highest levels of overstress on bridge superstructure elements.In order to simulate most accurately the actual field conditions, a criterion was defined which contained three major requirements: 1) The bridges utilized within the study shall be defined as being a statistically significant sample and be actual bridges taken from the NBI; 2) The analysis method shall be consistent with those actually used by engineers in designing and rating bridges, and; 3) The criteria utilized in evaluating the various bridge structures under the defined loadings shall be consistent with current practices.The results obtained indicates the acceptability of various truck configurations by GVW, size, and axle deployments, by system for the different criteria now in use.
Multiobjective pricing of bus‐subway services in Santiago, Chile
Authors: Jara‐Díaz Sergio R. , Tudela Alejandro M. 
Published: January 2010

AbstractPresently, the surface transit system in Santiago, Chile is private and atomized. It operates in competition with the subway, covering long distances and causing congestion in the central business district. As the subway operates below capacity, integrated services with a common fare have been identified as both operatively and financially possible, making better use of resources and avoiding negative externalities. A multi‐objective approach is formulated and applied to determine the price of the combined service, accounting for both users' benefits and operators' profit. The role of different parameters in the financial and operative constraints is analyzed in particular, as well as the conflicting nature of the objective functions. The non‐inferior set of solutions is constructed and analyzed both in the decision variables space and in the objectives space, and solutions are compared against the present conditions.
A study on adjustment factors for U‐turns in left‐turn lanes at signalized intersections
Authors: Tsao Shou‐Min , Chu Song‐Wei 
Published: January 2010

AbstractU‐turns are treated as left‐turns in the current procedures for estimating saturation flow rates at signalized intersections. While U‐turning vehicles are usually mixed with left‐turning vehicles in inside or left‐turn lanes and conflict with opposing through traffic as left‐turning vehicles, the vehicle operating characteristics are different. The objective of this paper is to investigate the effects of U‐turns on the traffic flow in left‐turn lanes.Field data of 600 headways of left‐turning passenger cars and 160 headways of U‐turning passenger cars are recorded. The average headways of U‐turning passenger cars are found to be significantly larger than those of left‐turning passenger cars. The effects of U‐turning vehicles depend upon the percent of U‐turning vehicles in the left‐turn lane, as well as the order of formation in the traffic stream. Adjustment factors for varying percents of U‐turning vehicles in left‐turn lanes are established.
Involving citizens in sustainable development: Scenario workshop on sustainable mobility
Authors: Nielsen Lise Drewes , Hansen Leif Gjesing 
Published: January 2010

AbstractThe scenario workshop is an example of the Scandinavian tradition of citizen involvement. The method is a mix of scenario and workshop. Scenarios produced by experts (scientists) are presented to a local community in a workshop lasting two to three days during which local participants produce criticism, debate and plans for community action. The method, originally used to actively involve citizens in the development of environmentally sustainable cities in Denmark, is now in use throughout Europe, as the various EU directorates have become very aware of their usefulness. A method has now been generated at the Copenhagen Business School for the field of transport. Four transport scenarios were generated relating to post‐Fordist production systems, transport and the concept of sustainable mobility. They are to be presented in a transport‐intensive region of Denmark to analyse barriers against environmentally induced adjustments to the transport sector and to find new solutions to the dilemma by creating dialogue between planners, politicians and transport managers.
A fuzzy measure based solution approach to a multimodal analysis problem
Authors: Dhingra S. L. , Ramanajee M. 
Published: January 2010

AbstractThis paper discusses the factors that determine the utility of a mode and attempts to suggest and investigate a novel fuzzy measure based solution approach to the problem of multimodal analysis in a multicriteria context. The paper expands on the notions of fuzzy logic and in particular, fuzzy measures. The approach attempts to estimate the probabilities of the “overall system” from a group of eight experts who are experienced in transport planning. The data is used to ascertain the relative utility of various modes in a competitive environment. It explains the application of fuzzy measures to provide guidance information for a transport planning agency.
Citizen involvement in the transportation planning process: What is and what ought to be
Authors: Khisty C. Jotin 
Published: January 2010

AbstractPublic involvement in the transportation planning process is an effort to ensure that citizens have a direct voice in public decision‐making. Through shared goals, such involvement enriches the planning, implementation, operation and management process. Various strategies of involving the public in the planning process have been tried in the past thirty years, but the overall effort has been lumpy and at times disappointing. In the last few years some forms of communicative action have been applied, following its appearance in current literature, but we still have a long way to go. This paper has four main objectives. First, it surveys the citizen involvement effort as it is practiced today and the problems it faces. Second, it describes teleogenic systems that are particularly suited for tackling conflictual problems. Thirdly, it presents the interplay of virtuous and vicious cycles in reinforcing or retarding collective decision making. And lastly, the process of harvesting the potential of citizen groups in collective decision‐making through critical systems thinking is described.
The impact of job assignment rules for straddle carriers on the throughput of container terminals
Authors: Behera J. M. , Diamond N. T. , Bhuta C. J. , Thorpe G. R. 
Published: January 2010

AbstractStraddle carriers represent a critical resource in the handling of containers within a container terminal. It is essential that they are deployed in an as efficient manner as possible. The research presented in this paper is motivated by the need to critically evaluate job assignment rules for straddle carriers that operate in a multiple straddle environment. This is achieved by developing a discrete event simulation model using industrial simulation software to model a container terminal located in Melbourne, Australia. The model accounts for variables such as the number of straddle carriers needed, the speed of straddle carriers, the arrival rate of trucks, and the job assignment rule. A principal finding of the study is that increasing the number of straddles in the present set‐up from 6 to 7 has a negligible effect on daily throughput. However, an increase in the number of straddles to 7 is expected to have a profound effect on reducing the average waiting time of trucks within the terminal from over 16 minutes to under 9 minutes, a decrease of 46.5%. However, a further increase in the number of straddles results in no further increase in daily throughput. It was observed that the throughput of the terminal is very sensitive to the speeds at which straddles travel.The management of the terminal has proposed a new heuristic job assignment rule for straddles, because the present rule does not assign the jobs to straddles closest to the truck requesting to load or unload a container. As a result a new heuristic job assignment rule was tested. The simulation results revealed that both the old and new rules performed equally well using performance indicators such as average container flow time, daily throughput, average waiting time of jobs, number of jobs in the queue, and straddle utilisation. Therefore, the new rule will not improve these performance measures if implemented
The car pooling problem: Heuristic algorithms based on savings functions
Authors: Ferrari Emilio , Manzini Riccardo , Pareschi Arrigo , Persona Alessandro , Regattieri Alberto 
Published: January 2010

AbstractThe present research deals with car pooling as a means of making better use of existing infrastructure and as a means of reducing traffic congestion with all its associated induced effects. Car pooling schemes involve several drivers getting together to share a private vehicle simultaneously, in order to reach their destinations points according to a semi‐common route rather than each driver using their own vehicle. The Car Pooling Problem belongs to the non‐polynomial computational complexity family of operations problems. In the current literature there are only a few studies on this optimization problem: the research group has designed several different new automatic and heuristic data processing routines to support efficient matching in car pool schemes. These are based on savings functions and belong to two distinct macro classes of algorithms to give two different modelings of this problem. They offer average savings of more than 50% in traveled distances demonstrating the effectiveness of a trivial matching scheme for real applications.
Value of leisure time based on individuals' mode choice behavior
Authors: Shiaw Ming‐Shong 
Published: January 2010

AbstractValues of time have been defined in various forms such as value of leisure time (shadow price of time), value of travel time, and value of saving time, and are mostly measured based on individuals' travel choice behavior. The main purpose of this study is to estimate the value of leisure time by general mode choice models. The estimated level can be used to evaluate the benefits from the increasing leisure time gained by people in Taiwan after the government has practiced a series of policies to shorten employee's working hours in the last few years. To justify the application, this study reviews and reinterprets the theoretical results of some major works on value of time derivations. Then to practically estimate the value of leisure time, it suggests a method of combining revealed preference and stated preference data for application. Finally, it conducts an empirical study on travelers' mode choices behavior in Taiwan to carry out the method suggested. The value of leisure time is estimated at 56NT$ per hour (around 1.65US$/hr), which is even lower than the minimum wage rate regulated by Taiwan government.
Sequential optimization approach for the multi‐class user equilibrium problem in a continuous transportation system
Authors: Ho H. W. , Wong S. C. , Loo Becky P. Y. 
Published: January 2010

AbstractWe consider a city region with several facilities that are competing for customers of different classes. Within the city region, the road network is dense, and can be represented as a continuum. Customers are continuously distributed over space, and they choose a facility by considering both the transportation cost and market externalities. More importantly, the model takes into account the different transportation cost functions and market externalities to which different customer classes are subjected. A logit‐type distribution of demand is specified to model the decision‐making process of users' facility choice. We develop a sequential optimization approach to decompose the complex multi‐class and multi‐facility problem into a series of smaller single‐class and single‐facility sub‐problems. An efficient solution algorithm is then proposed to solve the resultant problem. A numerical example is given to demonstrate the effectiveness and potential applicability of the proposed methodology.
A fraction of unripe kiwi fruit extract regulates adipocyte differentiation and function in 3T3‐L1 cells
Authors: Abe Daigo , Saito Takeshi , Kubo Yasutaka , Nakamura Yoshimasa , Sekiya Keizo 
Published: January 2010

AbstractAdipocyte dysfunction is strongly associated with the development of insulin resistance and diabetes, and regulation of adipogenesis is important in prevention of diabetes. We prepared a 100% methanol fraction of methanolic extract from unripe kiwi fruit (Actinidia deliciosa), designated KMF (kiwi fruit methanol fraction). When applied to 3T3‐L1 preadipocyte cells, KMF promoted adipocyte differentiation, increased glycerol‐3‐phosphate dehydrogenase (GPDH) activity, and increased triglyceride (TG) content. KMF markedly increased mRNA expression of peroxisome proliferator‐activated receptor γ (PPARγ)—the master adipogenic transcription factor—and its target genes. Moreover, KMF increased mRNA expression and protein secretion of adiponectin, whereas mRNA expression and secretion of monocyte chemoattractant protein‐1 (MCP‐1) and interleukin‐6 (IL‐6) were decreased. Compared with troglitazone, KMF decreased the production of reactive oxygen species (ROS) and nuclear factor‐kappaB (NFκB) activation. Glucose uptake was stimulated by KMF in differentiated 3T3‐L1 adipocytes. Taken together, these results indicate that KMF may exert beneficial effects against diabetes via its ability to regulate adipocyte differentiation and function.
Impact of portal vein embolization on long-term survival of patients with primarily unresectable colorectal liver metastases
Authors: Wicherts D A , de Haas R J , Andreani P , Sotirov D , Salloum C , Castaing D , Adam R , Azoulay D 
Published: January 2010

Abstract

Background
Portal vein embolization (PVE) increases the resectability of initially unresectable colorectal liver metastases (CLM). This study evaluated long-term survival in patients with CLM who underwent hepatectomy following PVE.

Methods
In a retrospective analysis patients treated by PVE before major hepatectomy were compared with those who did not have PVE, and with those who had PVE without resection.

Results
Of 364 patients who underwent hepatectomy, 67 had PVE beforehand and 297 did not. Those who had PVE more often had more than three liver metastases (68 versus 40·9 per cent; P &lt; 0·001) that were more frequently bilobar (78 versus 55·2 per cent; P &lt; 0·001), and a higher proportion underwent extended hepatectomy (63 versus 18·1 per cent; P &lt; 0·001). Postoperative morbidity rates were 55 and 41·1 per cent respectively (P = 0·035), and overall 3-year survival rates were 44 and 61·0 per cent (P = 0·001). Thirty-two other patients who were treated by PVE but did not undergo resection all died within 3 years.

Conclusion
PVE increased the resectability rate of initially unresectable CLM. Among patients who had PVE, long-term survival was better in those who had resection than in those who did not. PVE is of importance in the multimodal treatment of advanced CLM.
Protective effects of antioxidant combination against D‐galactosamine‐induced kidney injury in rats
Authors: Catal Tunc , Sacan Ozlem , Yanardag Refiye , Bolkent Sehnaz 
Published: January 2010

AbstractThe protective effects of an antioxidant combination in kidney injury induced by the injection of D‐galactosamine (D‐GaIN) were examined in the present study. Sprague Dawley female rats were used and divided into four groups as follows: (1) animals injected physiological saline solution, intraperitoneally, (2) animals treated with the combination of ascorbic acid (100 mg kg−1 day−1), β‐carotene (15 mg kg−1 day−1), α‐tocopherol (100 mg kg−1 day−1), and sodium selenate (0.2 mg kg−1 day−1) for three days orally, (3) rats injected D‐GaIN (500 mg kg−1) intraperitoneally as a single dose, and (4) animals treated with the antioxidant combination for three days, then injected D‐GaIN. The tissue and blood samples of animals were collected for morphological and biochemical evaluations. Histopathological injury in kidney tissues was observed together with a significant increase in tissue lipid peroxidation (LPO) level, myeloperoxidase (MPO), lactate dehydrogenase, catalase and superoxide dismutase (SOD) activities, and serum creatinine and urea levels, and a significant decrease in glutathione level and glutathione peroxidase activity in D‐GaIN injected rats. However, a decrease in the degenerative changes was detected in the kidney tissue of D‐GaIN + antioxidant group, and biochemical results showed reversed effects. In conclusion, it seems reasonable to conclude that the treatment of the antioxidant combination has a protective effect on D‐GaIN‐induced kidney injury of rats. Copyright © 2010 John Wiley & Sons, Ltd.
Erythroid 5‐aminolevulinate synthase mediates the upregulation of membrane band 3 protein expression by iron
Authors: Huang Qianchuan , Li Jinying , Feng Weihua , Xu Yanqun , Huang Zhenxia , Lv Shuqing , Zhou Hong , Gao Lei 
Published: January 2010

AbstractIron deficiency leads to abnormal expression and function of band 3 protein in erythrocytes, but the underlying mechanisms remain elusive. The mRNA of erythroid‐specific 5‐aminolevulinate synthase (eALAS) contains an iron response element and the eALAS protein is an important mediator of iron utilization by erythrocytes. In this study, we investigated the effect of short hairpin RNA (shRNA) mediated silencing of eALAS on the expression of band 3 protein induced by iron. By real‐time RT‐PCR and Western blot we showed that at mRNA and protein level iron‐induced expression of band 3 protein was lower in eALAS‐shRNA transfected K562 cells than in control cells. Of note, the lowest expression was detected in K562 cells cultured in iron deficiency condition (p < 0.01). Thus either iron deficiency or depletion of eALAS could suppress the expression of erythroid band 3 protein. These results demonstrated for the first time that iron and the iron‐regulatory system regulate the expression of the erythrocyte membrane proteins. Copyright © 2010 John Wiley & Sons, Ltd.