1,720,991 research outputs found
Energy-Efficient Train Operation: Conclusions and Future Work
No full textThis chapter gives the basic conclusions about energy-efficient train operation covering energy-efficient train driving, energy-efficient train timetabling, regenerative braking, energy storage systems and power supply networks. Future work that will develop energy-efficient train operation further include the interaction of connected driver advisory systems (C-DAS) and automatic train operation (ATO) with railway traffic management systems, cooperative train control in platoons of virtually coupled trains, digital twin technology and particularly its application to power supply systems, and the interaction between the railway network with the electrical power grid and renewable energy generation.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
Introduction to Energy-Efficient Train Operation
No full textRailway, as one of the most energy-efficient transport, plays an essential role in improving the world’s energy and environmental sustainability. Statistics about rail share of transport activities and the corresponding energy consumption will demonstrate the energy efficiency of railway and indicate the potential of developing railway transport. Therefore, this chapter will provide an overview of the railway's energy consumption and traffic volume shares. Statistics presented in this chapter show that railway energy consumption decreased in these decades while its transport volume kept stable, and the traffic volume share of the railway is extremely large in urban transport. To achieve the goal of carbon neutralization, the European Union and many countries have conducted research projects on railway energy conservation. The technologies developed in these projects include energy-efficient train driving, integrated timetabling, using regenerative braking energy, etc. A summary of these technologies is also given, along with their potential energy savings, which range from 1 to 25%. This book will analyse and illustrate the whole systems processes of train operation with optimisation solutions. The structure of the following chapters will be presented at the end.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
Energy-Efficient Train Timetabling
No full textRunning time calculation is an essential ingredient in train timetabling. Traditionally, the technical minimum running times are computed in detail after which a running time supplement is added to obtain the scheduled running times. This running time supplement must be translated into lower cruising speeds or coasting regimes to cover the entire scheduled running time for on-time running. How this is done determines the exact time-distance train paths and the energy consumption of the trains. This chapter explains how train trajectory optimization can be used to compute energy-efficient train trajectories between two stops, over multiple stops including the optimal allocation of running time supplements between the stops, and over corridors considering the track occupation of multiple trains. It is argued that microscopic train timetabling based on energy-efficient train trajectories and blocking time theory is required to design robust conflict-free timetables that enable energy-efficient train operation. The theory is illustrated with many examples under realistic conditions, such as varying gradients and speed restrictions.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
A three-level framework for performance-based railway timetabling
Full text linkThe performance of railway operations depends highly on the quality of the railway timetable. In particular for dense railway networks it can be a challenge to obtain a stable robust conflict-free and energy-efficient timetable with acceptable infrastructure occupation and short travel times. This paper presents a performance-based railway timetabling framework using an integrated approach on three levels: microscopic, macroscopic and a corridor fine-tuning level, to compute a timetable explicitly driven by the above mentioned performance indicators. A case study on the Dutch railway network illustrates the feasibility of this approach to achieve the highest timetabling design level.Transport & PlanningCivil Engineering and Geoscience
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Ein Schichtenmodell für den Entwurfsprozess der Eisenbahninfrastruktur
No full textFixed-interval timetables are central to the further development of rail networks because they better meet customers' needs. However, infrastructure is needed to make the service possible. It would be helpful to be able to derive the track topology directly from rail service, but to do this, several open questions need to be answered. This thesis aims to find and name these open questions for the design of service-oriented infrastructure. Inspired by ideas and discussions about the cycle of track topology design, a working hypothesis for improved integrated transport planning for a more transparent railway system design was developed to justify service-oriented infrastructure. Three research questions regarding the relationship between rail service and track topology were formulated from the working hypothesis. The method of design science research was utilised to answer the research questions. Design science research is centred around an artifact that is constructed in cycles. The developed artifact is a railway layer model with several layers between the track topology and the rail service. The design science research method began with assembling an initial artifact and modelling one layer per cycle upon the initial artifact. The modelling was done with an example railway network and the validating functions of the current layer in a cycle. The modelling was undertaken in the direction of rail service by beginning at the track topology layer. Reversing the direction after finishing the artifact was carried out to chart the railway infrastructure design process for a service-oriented infrastructure. As a first result, the layer model consisted of collections of data with a specific purpose. These collections were used to find a suitable reverse path for the design process for a service-oriented infrastructure. The second result was clusters of collections named motifs. There are eight motifs in the landscape of problems for direction rail service to track topology. Some motifs can already be considered solved, while others still require further research.Integrierte Taktfahrpläne spielen eine zentrale Rolle bei der Weiterentwicklung moderner Eisenbahnnetze, da sie den Bedürfnissen der Fahrgäste möglicherweise entgegenkommen. Um jedoch einen solchen Betrieb zu ermöglichen, ist eine geeignete Infrastruktur erforderlich. Die Möglichkeit, die Gleistopologie direkt aus einem Fahrplan abzuleiten, wäre von großem Nutzen, jedoch gibt es noch zahlreiche offene Fragen, die in diesem Zusammenhang beantwortet werden müssen. Ziel dieser Dissertation ist es, diese offenen Fragen zu identifizieren und einen Beitrag zur Gestaltung einer serviceorientierten Eisenbahninfrastruktur zu leisten. Ausgehend von bisherigen Überlegungen zur Zyklusgestaltung der Gleistopologie wird eine Arbeitshypothese vorgestellt, die eine verbesserte, integrierte Verkehrsplanung mit dem Ziel einer transparenten und serviceorientierten Infrastruktur vorschlägt. Auf dieser Grundlage werden drei zentrale Forschungsfragen formuliert, die das Zusammenspiel zwischen Fahrplan und Gleistopologie untersuchen. Zur Beantwortung dieser Fragen wird die Design-Science-Research-Methode angewendet, die sich auf die schrittweise Entwicklung eines Artefakts in iterativen Zyklen konzentriert. Das im Rahmen dieser Arbeit entwickelte Artefakt ist ein mehrschichtiges Modell des Eisenbahnsystems, das die verschiedenen Ebenen zwischen Gleistopologie und Fahrplan darstellt. Der Forschungsprozess begann mit der Erstellung eines Ausgangs-Artefakts, das in mehreren Zyklen weiterentwickelt wurde, wobei pro Zyklus jeweils eine weitere Schicht modelliert wurde. Diese Modellierung erfolgte anhand eines Beispiel-Eisenbahnnetzes, wobei jede Schicht auf ihre Validität hin überprüft wurde. Der Prozess startete bei der Gleistopologie und führte schrittweise zum Fahrplan, bevor die Reihenfolge umgekehrt wurde, um die serviceorientierte Gestaltung der Infrastruktur zu entwickeln. Als vordergründiges Ergebnis liefert das Schichtenmodell eine Sammlung spezifischer Datensätze, die zur Entwicklung eines Rückwärtspfads für den Entwurfsprozess einer serviceorientierten Infrastruktur genutzt werden können. Das zweite Ergebnis besteht in der Identifizierung von acht zentralen Problemstellungen ("Motive") im Zusammenspiel von Fahrplan und Gleistopologie. Einige dieser Motive sind bereits weitgehend gelöst, während andere noch weiterer Forschung bedürfen
The contribution to 3kV traction power supply system on railway capacity in the Netherlands
No full textThe current 1.5kV railway traction power supply system is reaching its limits in the Netherlands and therefore, ProRail is investigating the replacement of this system by the 3kV railway traction power supply system. This study will investigate how effective the 3kV traction power supply system can increase the capacity of the rail infrastructure in the Netherlands. It will also investigate if this system can avoid other capacity investments in the infrastructure. Several study cases will be executed in order to evaluate the capacity effects of the 3kV traction power supply system
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