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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Evaluation de performance d’une ligne ferroviaire suburbaine partiellement équipée d’un automatisme CBTC / Performance of a suburban railway line partially equipped with a CBTC system

Pochet, Juliette 12 January 2018 (has links)
En zone dense, la croissance actuelle du trafic sur les lignes ferroviaires suburbaines conduit les exploitants à déployer des systèmes de contrôle-commande avancés des trains, tels que les systèmes dits « CBTC » (Communication Based Train Control) jusque-là réservés aux systèmes de métro. Les systèmes CBTC mettent en œuvre un pilotage automatique des trains et permettent une amélioration significative des performances. Par ailleurs, ils peuvent inclure un module de supervision de la ligne en charge de réguler la marche des trains en cas d’aléa, améliorant ainsi la robustesse du trafic. Face au problème de régulation, la recherche opérationnelle a produit un certain nombre de méthodes permettant de répondre efficacement aux perturbations, d’une part dans le secteur métro et d’autre part dans le secteur ferroviaire lourd. En tirant profit de l’état de l’art et des avancées faites dans les deux secteurs, les travaux présentés dans ce manuscrit cherchent à contribuer à l’adaptation des fonctions de régulation des systèmes CBTC pour l’exploitation de lignes ferroviaires suburbaines. L’approche du problème débute par la construction de l’architecture fonctionnelle d’un module de supervision pour un système CBTC standard. Nous proposons ensuite une méthode de régulation basée sur une stratégie de commande prédictive et sur une optimisation multi-objectif des consignes des trains automatiques. Afin d’être en mesure d’évaluer précisément les performances d’une ligne ferroviaire suburbaine équipée d’un automatisme CBTC, il est nécessaire de s’équiper d’un outil de simulation microscopique adapté. Nous présentons dans ce manuscrit l’outil SNCF nommé SIMONE qui permet une simulation réaliste du point de vue fonctionnel et dynamique d’un système ferroviaire incluant un système CBTC. Les objectifs des travaux de thèse nous ont naturellement conduits à prendre part, avec l’équipe SNCF, à la spécification, à la conception et à l’implémentation de cet outil. Finalement, grâce à l’outil SIMONE, nous avons pu tester la méthode de régulation proposée sur des scénarios impliquant des perturbations. Afin d’évaluer la qualité des solutions, la méthode multi-objectif proposée a été comparée à une méthode de régulation individuelle basée sur une heuristique simple. La méthode de régulation multi-objectif propose de bonnes solutions au problème, dans la majorité des cas plus satisfaisantes que celles proposées par la régulation individuelle, et avec un temps de calcul jugé acceptable. Le manuscrit se termine par des perspectives de recherche intéressantes. / In high-density area, the demand for railway transportation is continuously increasing. Operating companies turn to new intelligent signaling and control systems, such as Communication Based Train Control (CBTC) systems previously deployed on underground systems only. CBTC systems operate trains in automatic pilot and lead to increase the line capacity without expensive modification of infrastructures. They can also include a supervision module in charge of adapting train behavior according to operating objectives and to disturbances, increasing line robustness. In the literature of real-time traffic management, various methods have been proposed to supervise and reschedule trains, on the one hand for underground systems, on the other hand for railway systems. Making the most of the state-of-the-art in both fields, the presented work intend to contribute to the design of supervision and rescheduling functions of CBTC systems operating suburban railway systems. Our approach starts by designing a supervision module for a standard CBTC system. Then, we propose a rescheduling method based on a model predictive control approach and a multi-objective optimization of automatic train commands. In order to evaluate the performances of a railway system, it is necessary to use a microscopic simulation tool including a CBTC model. In this thesis, we present the tool developed by SNCF and named SIMONE. It allows realistic simulation of a railway system and a CBTC system, in terms of functional architecture and dynamics. The presented work has been directly involved in the design and implementation of the tool. Eventually, the proposed rescheduling method was tested with the tool SIMONE on disturbed scenarios. The proposed method was compared to a simple heuristic strategy intending to recover delays. The proposed multi-objective method is able to provide good solutions to the rescheduling problem and over-performs the simple strategy in most cases, with an acceptable process time. We conclude with interesting perspectives for future work.
262

Design optimization of double excitation synchronous machines in railway traction / Conception par optimisation des machines synchrones à double excitation dédiée à la traction ferroviaire

Hoang, Trung-Kien 25 November 2016 (has links)
Les machines électriques classiques comme les machines asynchrones et les machines à aimant permanent sont largement utilisées dans ces applications de traction, et surtout en traction ferroviaire. Cette thèse évalue la contribution d'un autre type de machines, appelé machines synchrones à double excitation dans cette même application. Le terme double excitation signifie que le flux de la machine est créé par deux sources : le bobinage d'excitation et les aimants permanents. Le degré de liberté fourni par le bobinage d'excitation permet d’atteindre l’objectif d’amélioration de l’efficacité. Ce travail a pour but d’identifier les avantages des machines à double excitation sur un cycle de conduite spécifique. Il définira également les cas dans lesquels cette machine fournira de meilleures performances que celles des machines classiques.Les études récentes considèrent uniquement l’optimisation des systèmes en optimisant chaque composant du système séparément. Cependant, avoir les meilleurs performances dans chacun de ces composants ne signifie pas avoir un meilleur système. Afin d'atteindre des résultats plus réalistes, un modèle multi-physique prenant en compte la non linéarité des matériaux sera développé. Ce modèle intègre également les différents aspects comme l’électromagnétisme, la thermique, la mécanique et l’électronique de puissance. / Classical electrical machines such as asynchronous and permanent magnet synchronous machines have been widely applied in traction applications and particularly in railway traction. This thesis, however, evaluate the contribution of a special class of synchronous machine called textbf{D}ouble textbf{E}xcitation textbf{S}ynchronous textbf{M}achine (DESM) for the railway traction. Double excitation term indicates that the field flux of the machine is created by two sources: excitation windings and permanent magnets. The degree of freedom provided by the excitation windings provides the opportunity to work on the energy efficiency improvement target. This thesis will try to answer the question whether DESM is more advantageous over classical machines in a specific driving cycle and in addition, in which cases a DESM performs better.Recent studies have merely optimized the individual components, the major drawback of this approach is that the combination of the best individuals does not necessarily form a best system. In order to achieve more realistic results, a multi-physic models taking into account nonlinear characteristic and various disciplines such as electromagnetic, thermal, mechanical and power electronics will be developed.
263

Terminál Poděbrady VRT / Railway Station Podebrady HSR

Piruš, Erik Unknown Date (has links)
The master´s thesis deals with the design of the transfer terminal on the proposed high speed railway Prague - Hradec Kralove - Wroclaw near the town of Podebrady and exit 39 from the D11 motorway. The work includes the design of station layout, platforms, access roads, bus stops and parking house. As part of the railway station design naintenance base with the loading area. The integral parts of the thesis is design of the railway superstructure, substructure and drainage system.
264

Standardisering av bullerskärm för järnväg : En undersökning för Peab och Trafikverket / Standardizing noise barriers for railways : An analysis for Peab and Trafikverket

Djulstedt, Fredrik, Gronowski, Diego January 2014 (has links)
I dagsläget dimensioneras bullerskärmar efter varje projekt med den enda gemensamma nämnaren att de skall uppfylla utformade riktlinjer och bullerkrav. De kan skilja sig enormt vad gäller estetisk utformning och konstruktion. Denna arbetsgång är både tids - och kostnadsineffektiv med konsekvenser som följd, framförallt då externa arkitekter anställs för att sätta sin egen prägel. Uppgiften har utdelats gemensamt utav Trafikverket och Peab som ser ett behov utav standardiserade bullerskärmar. Slutsatsen har dragits utav tidigare projekt och då framförallt projekt Mälarbanan. Denna rapport syftar till att, med utgångspunkt Mälarbanan, ta fram ett förslag till ett standardiserat system som skall kunna användas runt om i Sverige. Detta system, skall motverka dagens problematik med nuvarande bullerskärmar. Systemet kommer i texten att benämnas som Bsk 14F som står för Bullerskärm 14 Försök. Resultatet utav Bsk 14F kommer att redovisas med ljudmodelleringar i dataprogrammet INSUL som används i dagens utformningar. Ritningar i CAD kommer att påvisa Bsk 14Fs konstruktion och kalkylräkning för kostnaderna. Vi har även jämfört olika bullerskärmar som finns att tillgå på marknaden idag för att undersöka möjligheten att välja ett befintligt system. Med hjälp av en yrkesverksam akustiker, konstruktörer, platschefer och arbetsledare har vi kunnat erhålla underlag för att producera ett slutligt resultat. Här påvisas att med ett standardiserat system går det att uppnå ljudkraven som erfordras till ett lägre pris utan att behöva kompromissa utrymme för arkitektoniskt prägel. / Ideally, the basic standard forms of how and why noise barriers are created are to fulfill the purpose of reducing sound. They vary greatly regarding their esthetics and design. Particular mechanics are both time and cost ineffective consequentially when external architects are contracted to put their trademark on them. Trafikverket and Peab, whom identify the need of standardizing noise barriers, have collaboratively delegated the assignment. The conclusion has been drawn from earlier projects and Project Mälarbanan. The premise of the report (having Mälarbanan as an example) is to offer a standardized system which would be used throughout Sweden. This system would, thus, counter the current problems with noise barriers that exist today. The system will be noted in the text as Bsk 14F, which stands for Bullerskärm 14 Försök (Noise Barrier 14 experimental). A computer sound-model program using today’s configurations will present the results of Bsk 14F, whereas drawings in CAD will show Bsk 14F’s design and calculation costs. A comparison has also been made to examine the possibility of choosing a noise barrier currently existing on the market today. With the help of effectively using a professional acoustician, engineers, site managers, and project leaders was it possible to obtain the core material to produce an ultimate and final result. The following demonstrates that establishing a standardized system, which fulfills the sound requirements and be constructed at a lower cost, is attainable without having to comprise the architectural trademark.
265

History of Railway Development in China

Dawson, Homer W. 08 1900 (has links)
This study attempts to provide detailed analysis of materials gathered from various sources and to an orderly presentation of facts and figures regarding railway construction in China.
266

On the Effect of Track Irregularities on the Dynamic Response of Railway Vehicles

Elmaraghy, Waguih H. 02 1900 (has links)
<p> The steady state response for models of an actual six-axle locomotive running on a sinusoidally irregular track is investigated. Three mathematical models are set up, a simplified model which assumed no springing or damping of trucks or motors, and no creep forces, a full model for the "stationary" vehicle in which creep forces are assumed negligible and a full model for the "moving" vehicle, which creep forces, gravity stiffness effects and wheel tread profiles are considered. </p> <p> The steady state response of the vehicle components to varying input frequencies is calculated and the response curves are computer plotted in each case. The natural frequencies for the simplified and the full model are also calculated. For the "moving" vehicle responses for the cases of new and worn wheels are obtained. Effect of creep and wheel tread profiles is studied. </p> The accuracy with which each of the devised models describe the performance of the real railway vehicle is compared. A discussion of the conclusions drawn from the analysis, including the applications to the design of high speed railway vehicles is given. Much attention was devoted to the development and testing of five computer programs for which simplified flow charts are given in Appendix V. </p> / Thesis / Master of Engineering (ME)
267

A Preparatory Study Towards a Body of Knowledge in the Field of Formal Methods for the Railway Domain

Kumar, Apurva 11 1900 (has links)
Bodies or Books of Knowledge (BoKs) have only been transcribed in mature fields where practices and rules have been well established (settled) and are gathered for any prospective or current practitioner to refer to. As a precursor to creating a BoK, it is first important to know if the domain contains settled knowledge and how this knowledge can be isolated? One approach, as described in this work, is to use Formal Concept Analysis (FCA) to structure the knowledge (or parts of it) and construct a pruned concept lattice to highlight patterns of use and filter out the common and established practices that best suit the solving of a problem within the domain. In the railway domain, formal methods have been applied for a number of years to solve various modelling and verification problems. Their common use and straightforward application (with some refinement) makes them easy to identify and therefore a prime candidate to test for settled knowledge within the railway domain. They also provide other assurances of settled knowledge along the way. / Thesis / Master of Applied Science (MASc)
268

Effects of the Hamilton Street Railway Strike of 1982 on Downtown Businesses

Piccioni, Emidio S. 04 1900 (has links)
<p> This study investigates the effects of transit strikes on the central business districts (C.B.D. 's) of large cities. It focuses directly on the Hamilton Street Railway (H.S.R.) strike which occurred during the summer of 1982, and attempts to outline exactly what age-groups were affected the most and whether or not the merchants of the downtown were significantly affected monetarily. Information was acquired from merchants through the circulation of a questionnaire which was distributed in September and October of 1983. A regression equation was formulated which took into account some possible causes for diminishing revenues other than the transit strike. The findings of this analysis were that the transit strike had a significant effect on the revenues of downtown businesses, as well as on the age-groups that were present in the downtown at the time of the strike. The regression analysis found that the other factors which were considered did not account for a very significant proportion of decreased revenues when compared to transit strikes.</p> / Thesis / Candidate in Philosophy
269

RAILWAY CAPACITY MANAGEMENT AND PLANNING

HARROD, STEVEN S. 09 October 2007 (has links)
No description available.
270

The Application of Doppler LIDAR Technology for Rail Inspection and Track Geometry Assessment

Taheriandani, Masood 17 May 2016 (has links)
The ability of a Doppler LIDAR (Light Detection and Ranging) system to measure the speed of a moving rail vehicle in a non-contacting manner is extended to capture the lateral and vertical irregularities of the track itself and to evaluate the rail track quality. Using two pairs of lenses to capture speed signals from both rails individually, the track speed, curvature, and lateral and vertical geometry variations on each side are determined. LIDAR lenses are installed with a slight forward angle to generate velocity signals that contain two components: 1) the left and right track speeds, and 2) any lateral and/or vertical speed caused by track motion and/or spatial irregularities. The LIDAR system collects and outputs the track information in time domain. Separating each speed component (forward, vertical, and lateral) is possible due to the inherent separation of each phenomenon with respect to its spatial/temporal frequencies and related bandwidths. For the measurements to be beneficial in practice, the LIDAR data must be spatially located along the track. A data-mapping algorithm is then simultaneously developed to spatially match the LIDAR track geometry measurements with reference spatial data, accurately locating the measurements along the track and eliminating the need for a Global Positioning System (GPS). A laboratory-grade LIDAR system with four Doppler channels, developed at the Railway Technologies Laboratory (RTL) of Virginia Tech, is body-mounted and tested onboard a geometry measurement railcar. The test results indicate a close match between the LIDAR measurements and those made with existing sensors onboard the railcar. The field-testing conducted during this study indicates that LIDAR sensors could provide a reliable, non-contact track-monitoring instrument for field use, in various weather and track conditions, potentially in a semi-autonomous or autonomous manner. A length-based track quality index (TQI) is established to quantify the track geometry condition based on the geometry data collected by the LIDAR sensors. A phenomenological rail deterioration model is developed to predict the future degradation of geometry quality over the short track segments. The introduced LIDAR's TQI is considered as the condition-parameter, and an internal variable is assumed to govern the rail geometry degradation through a deterioration rule. The method includes the historical data, current track conditions collected by the LIDAR system, and traffic data to calculate the track deterioration condition and identify the geometry defects. In addition to rail geometry inspection, a LIDAR system can potentially be used to monitor the rail surface structure and integrity. This is possible due to the fact that the Doppler shift imposed on the laser radiation reflected from a moving surface has the Doppler bandwidth broadened in proportion to the height and width of the surface features. Two LIDAR-based rail surface measures are introduced based on LIDAR measurements to identify different rail surface conditions and materials. / Ph. D.

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