Download or read book Models for Railway Track Allocation written by Ralf Borndörfer and published by . This book was released on 2007 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "The optimal track allocation problem (OPTRA) is to find, in a given railway network, a conflict free set of train routes of maximum value. We study two types of integer programming formulations for this problem: a standard formulation that models block conflicts in terms of packing constraints, and a novel formulation of the 'extended' type that is based on additional 'configuration' variables. The packing constraints in the standard formulation stem from an interval graph and can therefore be separated in polynomial time. It follows that the LP-relaxation of a strong version of this model, including all clique inequalities from block conflicts, can be solved in polynomial time. We prove that the LP-relaxation of the extended formulation can also be solved in polynomial time, and that it produces the same LP-bound. Albeit the two formulations are in this sense equivalent, the extended formulation has advantages from a computational point of view. It features a constant number of rows and is amenable to standard column generation techniques. Results of an empirical model comparison on mesoscopic data for the Hanover-Fulda-Kassel region of the German long distance railway network involving up to 570 trains are reported."

Download or read book Railway Track Allocation written by Thomas Schlechte and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2012-03 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is about mathematical optimization for the efficient use of railway infrastructure. We address the optimal allocation of the available railway track capacity - the track allocation problem. This track allocation problem is a major challenge for a railway company, independent of whether a free market, a private monopoly, or a public monopoly is given. Planning and operating railway transportation systems is extremely hard due to the combinatorial complexity of the underlying discrete optimization problems, the technical intricacies, and the immense sizes of the problem instances. Mathematical models and optimization techniques can result in huge gains for both railway customers and operators, e.g., in terms of cost reductions or service quality improvements. We tackle this challenge by developing novel mathematical models and associated innovative algorithmic solution methods for large scale instances. This allows us to produce for the first time reliable solutions for a real world instance, i.e., the Simplon corridor in Switzerland.

Download or read book A Suitable Model for a Bi criteria Optimization Approach to Railway Track Allocation written by Ralf Borndörfer and published by . This book was released on 2008 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Optimization in the Railway Industry written by Ralf Borndörfer and published by Springer. This book was released on 2018-03-01 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book promotes the use of mathematical optimization and operations research methods in rail transportation. The editors assembled thirteen contributions from leading scholars to present a unified voice, standardize terminology, and assess the state-of-the-art. There are three main clusters of articles, corresponding to the classical stages of the planning process: strategic, tactical, and operational. These three clusters are further subdivided into five parts which correspond to the main phases of the railway network planning process: network assessment, capacity planning, timetabling, resource planning, and operational planning. Individual chapters cover: Simulation Capacity Assessment Network Design Train Routing Robust Timetabling Event Scheduling Track Allocation Blocking Shunting Rolling Stock Crew Scheduling Dispatching Delay Propagation

Download or read book Solving Railway Track Allocation Problems written by Ralf Borndörfer and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Towards optimal railway track utilization based on societal benefit written by Victoria Svedberg and published by Linköping University Electronic Press. This book was released on 2018-10-12 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrastructure managers in railway systems are striving to have as e?cient track utilization as possible. There are no unanimous interpretation of e?ciency in terms of track utilization, but the aim of the Swedish Transport Administration is to allocate track capacity such that societal bene?t is maximized. This means that the tracks should be used by as much tra?c as possible and by tra?c that provides as much bene?t for the society as possible. To allocate track capacity such that the track utilization is optimal would be an easy task if the track capacity were not a scarce resource. Today, many train operators share railway network and there are cases when two or more operators want to use the same track capacity at the same time. The infrastructure manager must then make priorities and reject some operators, and the question is which operators to reject. The guiding principle is to grant the operators that provide the highest societal bene?t access to the tracks. However, the question would then change into how to know which operator that provides the highest societal bene?t. In this thesis, the societal bene?t of publicly subsidized tra?c is estimated using social cost-bene?t analysis. Mathematical models and methods are developed for quantifying and computing the number of departures for the publicly subsidized tra?c and their distribution in time, i.e. a train timetable, that provides the maximal societal bene?t in a social cost-bene?t analysis setting. The societal bene?t of commercial tra?c is estimated using the market value for their requested train timetables. The market value is set using dynamic pricing. A suggestion of a dynamic pricing process that can be used in the train timetabling process is described. Mathematical models and methods for calculating the supply and demand of a track access request are developed and tested, which enables the use of a dynamic pricing process on track capacity

Download or read book Operations Research Proceedings 2012 written by Stefan Helber and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​This book contains selected papers presented at the "International Annual Conference of the German Operations Research Society (OR2012)" which was held September 4 -7, 2012 at the Leibniz Universität Hannover, Germany. The international conference, which also serves as the annual meeting of the German Operations Research Society (GOR), attracted more than 500 participants from more than 39 countries. Special attention at the conference was given to the three topics "Energy, Markets and Mobility". The OR2012 conference has addressed these topics from an OR perspective, treating them not only in isolation, but also with respect to their numerous and exciting interconnections, such as new energy for new mobility concepts and new market mechanisms for sustainable energy production to name but a few. The proceedings show that this conference topic is an important and promising area to apply Operations Research. The book also contains numerous papers addressing the full scope of fields in Operations Research.

Download or read book Methods for Capacity Allocation in Deregulated Railway Markets written by Abderrahman Ait Ali and published by Linköping University Electronic Press. This book was released on 2020-10-01 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Faced with increasing challenges, railways around Europe have recently undergone major reforms aiming to improve the efficiency and competitiveness of the railway sector. New market structures such as vertical separation, deregulation and open access can allow for reduced public expenditures, increased market competition, and more efficient railway systems. However, these structures have introduced new challenges for managing infrastructure and operations. Railway capacity allocation, previously internally performed within monopolistic national companies, are now conferred to an infrastructure manager. The manager is responsible for transparent and efficient allocation of available capacity to the different (often competing) licensed railway undertakings. This thesis aims at developing a number of methods that can help allocate capacity in a deregulated (vertically separated) railway market. It focuses on efficiency in terms of social welfare, and transparency in terms of clarity and fairness. The work is concerned with successive allocation of capacity for publicly controlled and commercial traffic within a segmented railway market. The contributions include cost benefit analysis methods that allow public transport authorities to assess the social welfare of their traffic, and create efficient schedules. The thesis also describes a market-based transparent capacity allocation where infrastructure managers price commercial train paths to solve capacity conflicts with publicly controlled traffic. Additionally, solution methods are developed to help estimate passenger demand, which is a necessary input both for resolving conflicts, and for creating efficient timetables. Future capacity allocation in deregulated markets may include solution methods from this thesis. However, further experimentations are still required to address concerns such as data, legislation and acceptability. Moreover, future works can include prototyping and pilot projects on the proposed solutions, and investigating legal and digitalisation strategies to facilitate the implementation of such solutions. Med ökande utmaningar har järnvägar runt om i Europa genomgått stora reformer som syftar till att förbättra järnvägssektorns effektivitet och konkurrenskraft. Nya marknadsstrukturer såsom vertikal separering, avreglering och öppet tillträde för flera operatörer kan möjliggöra minskade offentliga kostnader, ökad marknadskonkurrens och effektivare järnvägssystem. Denna omreglering av järnvägsmarknaderna har dock skapat nya utmaningar för hanteringen av järnvägsinfrastruktur och drift. Tilldelning av järnvägskapacitet, vilket tidigare sköttes inom nationella monopolföretag, måste nu göras av en infrastrukturförvaltare (infrastructure manager). Förvaltarens kapacitetstilldelning till olika (ofta konkurrerande) licensierade järnvägsföretag (railway undertakings) måste samtidigt vara transparent, rättvis och leda till ett effektivt kapacitetsutnyttjande. I denna avhandling utvecklas metoder som kan användas av en infrastrukturförvaltare för att tilldela kapacitet i en avreglerad järnvägsmarknad. Den fokuserar på samhällsekonomiskt effektiva utfall men även transparens, tydlighet och rättvisa. Avhandlingens bidrag omfattar samhällsekonomiska analysmetoder som gör det möjligt för regionala kollektivtrafikmyndigheter att bedöma den samhällsekonomiska effektiviteten för deras trafikering och skapa ett effektivt utbud. Med dessa metoder som utgångspunkt beskrivs en marknadsbaserad och transparent tilldelningsprocess för kapacitet där infrastrukturförvaltare prissätter kommersiella tåglägen för att lösa kapacitetskonflikter med offentligt kontrollerad trafik. Dessutom utvecklas optimeringsmetoder för att estimera passagerarefterfrågan och för att skapa effektiva tågtidtabeller. Framtida kapacitetstilldelning på avreglerade marknader kan inkludera lösningsmetoder från denna avhandling. Ytterligare experiment krävs dock fortfarande för att hantera problem såsom data, lagstiftning och godtagbarhet. Dessutom kan framtida arbete omfatta prototyper och pilotprojekt av de föreslagna lösningarna och undersöka lagliga och digitaliseringsstrategier för att underlätta implementeringen av sådana lösningar.

Download or read book Railway Track Allocation Simulation Aggregation and Optimization written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Railway Track Allocation Simulation and Optimization written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Railway Track Allocation by Rapid Branching written by Ralf Borndörfer and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Operations research models for scheduling railway infrastructure maintenance written by Gabriella Budai-Balke and published by Rozenberg Publishers. This book was released on 2009 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis can be divided into two parts. In Part I we are dealing with the problem of finding optimal time intervals for carrying out routine maintenance works and large projects in such a way that the track possession costs and maintenance costs are minimized. In Part II of this thesis we focus on rescheduling of the rolling stock in the passenger railways due to changing circumstances and more precisely on the Rolling Stock Rebalancing Problem (RSRP). The main objectives of this thesis are formulated as follows: 1. Review the existing literature on maintenance planning in relation with production. 2. Identify some tactical and operational railway infrastructure maintenance planning problems and develop operations research models for providing decision support. Investigate the effect of planning railway infrastructure maintenance on the train operation and identify rolling stock planning problems that occur during planned infrastructure maintenance. 3. Analyze the considered models, investigate their computational complexity, propose solution methods and test the solutions of the models.

Download or read book Optimization Based Methods for Revising Train Timetables with Focus on Robustness written by Fahimeh Khoshniyat and published by Linköping University Electronic Press. This book was released on 2016-12-01 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: With increase in the use of railway transport, ensuring robustness in railway timetables has never been this important. In a dense railway timetable even a small disturbance can propagate easily and affect trains' arrival and departure times. In a robust timetable small delays are absorbed and knock-on effects are prevented effectively. The aim of this thesis is to study how optimization tools can support the generation of robust railway traffic timetables. We address two Train Timetabling Problems (TTP) and for both problems we apply Mixed Integer Linear Programming (MILP) to solve them from network management perspectives. The first problem is how robustness in a given timetable can be assessed and ensured. To tackle this problem, a headway-based method is introduced. The proposed method is implemented in real timetables and evaluated from performance perspectives. Furthermore, the impact of the proposed method on capacity utilization, heterogeneity and the speed of trains, is monitored. Results show that the proposed method can improve robustness without imposing major changes in timetables. The second problem addressed in the thesis is how robustness can be assessed and maintained in a given timetable when allocating additional traffic and maintenance slots. Different insertion strategies are studied and their consequences on capacity utilization and on the properties of the timetables are analyzed. Two different insertion strategies are considered: i) simultaneous and ii) stepwise insertion. The results show that inserting the additional trains simultaneously usually results in generating more optimal solutions. However, solving this type of problem is computationally challenging. We also observed that the existing robustness metrics cannot capture the essential properties of having more robust timetables. Therefore we proposed measuring Channel Width, Channel Width Forward, Channel Width Behind and Track Switching. Furthermore, the experimental analysis of the applied MILP model shows that some cases are computationally hard to solve and there is a need to decrease the computation time. Hence several valid inequalities are developed and their effects on the computation time are analyzed. This thesis contains three papers which are appended. The results of this thesis are of special interests for railway traffic planners and it would support their working process. However, railway traffic operators and passengers also benefit from this study.

Download or read book Experimental Algorithms written by Jan Vahrenhold and published by Springer Science & Business Media. This book was released on 2009-05-22 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 8th International Symposium on Experimental and Efficient Algorithms, SEA 2009, held in Dortmund, Germany, in June 2009. The 23 revised full papers were carefully reviewed and selected from 64 submissions and present current research on experimental evaluation and engineering of algorithms, as well as in various aspects of computational optimization and its applications. Contributions are supported by experimental evaluation, methodological issues in the design and interpretation of experiments, the use of (meta-) heuristics, or application-driven case studies that deepen the understanding of a problem's complexity.

Download or read book Proceedings of the 1st International Workshop on High Speed and Intercity Railways written by Yi-Qing Ni and published by Springer Science & Business Media. This book was released on 2012-02-13 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the papers included in the proceedings of the 1st International Workshop on High-speed and Intercity Railways (IWHIR 2011) held in Shenzhen and Hong Kong, China from July 19 to July 22, 2011, which is organized by The Hong Kong Polytechnic University, in collaboration with Southwest Jiaotong University, Beijing Jiaotong University, Dalian Jiaotong University, China Engineering Consultants, Inc., Zhejiang University, and Tsinghua University. Continuing the great initiatives and momentums of the rapid development in high-speed and intercity railways worldwide in recent years, IWHIR 2011 aims at providing a platform for academic scholars and practicing engineers to share knowledge and experience, to promote collaboration, and to strengthen R&D activities related to railway engineering. Engineers, scientists, professors, and students from universities, research institutes, and related industrial companies have been cordially invited to participate in the workshop. These papers have covered a wide range of issues concerning high-speed and intercity railways in the theoretical, numerical, and experimental work pertaining to high-speed and intercity railways. Showcasing diversity and quality, these papers report the state-of-the-art and point to future directions of research and development in this exciting area.

Download or read book Advances in RAMS Engineering written by Durga Rao Karanki and published by Springer Nature. This book was released on 2019-12-10 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book surveys reliability, availability, maintainability and safety (RAMS) analyses of various engineering systems. It highlights their role throughout the lifecycle of engineering systems and explains how RAMS activities contribute to their efficient and economic design and operation. The book discusses a variety of examples and applications of RAMS analysis, including: • software products; • electrical and electronic engineering systems; • mechanical engineering systems; • nuclear power plants; • chemical and process plants and • railway systems. The wide-ranging nature of the applications discussed highlights the multidisciplinary nature of complex engineering systems. The book provides a quick reference to the latest advances and terminology in various engineering fields, assisting students and researchers in the areas of reliability, availability, maintainability, and safety engineering.

Download or read book Graph Theory for Operations Research and Management Applications in Industrial Engineering written by Farahani, Reza Zanjirani and published by IGI Global. This book was released on 2012-12-31 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: While typically many approaches have been mainly mathematics focused, graph theory has become a tool used by scientists, researchers, and engineers in using modeling techniques to solve real-world problems. Graph Theory for Operations Research and Management: Applications in Industrial Engineering presents traditional and contemporary applications of graph theory in the areas of industrial engineering, management science, and applied operations research. This comprehensive collection of research introduces the useful basic concepts of graph theory in real world applications.