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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.
31

Detecting non-line of sight to prevent accidents in Vehicular Ad hoc Networks

Alodadi, Khaled January 2015 (has links)
There are still many challenges in the field of VANETs that encouraged researchers to conduct further investigation in this field to meet these challenges. The issue pertaining to routing protocols such as delivering the warning messages to the vehicles facing Non-Line of Sight (NLOS) situations without causing the storm problem and channel contention, is regarded as a serious dilemma which is required to be tackled in VANET, especially in congested environments. This requires the designing of an efficient mechanism of routing protocol that can broadcast the warning messages from the emergency vehicles to the vehicles under NLOS, reducing the overhead and increasing the packet delivery ratio with a reduced time delay and channel utilisation. The main aim of this work is to develop the novel routing protocol for a high-density environment in VANET through utilisation of its high mobility features, aid of the sensors such as Global Positioning System (GPS) and Navigation System (NS). In this work, the cooperative approach has been used to develop the routing protocol called the Co-operative Volunteer Protocol (CVP), which uses volunteer vehicles to disseminate the warning message from the source to the target vehicle under NLOS issue; this also increases the packet delivery ratio, detection of NLOS and resolution of NLOS by delivering the warning message successfully to the vehicle under NLOS, thereby causing a direct impact on the reduction of collisions between vehicles in normal mode and emergency mode on the road near intersections or on highways. The cooperative approach adopted for warning message dissemination reduced the rebroadcast rate of messages, thereby decreasing significantly the storm issue and the channel contention. A novel architecture has been developed by utilising the concept of a Context-Aware System (CAS), which clarifies the OBU components and their interaction with each other in order to collect data and take the decisions based on the sensed circumstances. The proposed architecture has been divided into three main phases: sensing, processing and acting. The results obtained from the validation of the proposed CVP protocol using the simulator EstiNet under specific conditions and parameters showed that performance of the proposed protocol is better than that of the GRANT protocol with regard to several metrics such as packet delivery ratio, neighbourhood awareness, channel utilisation, overhead and latency. It is also successfully shown that the proposed CVP could detect the NLOS situation and solves it effectively and efficiently for both the intersection scenario in urban areas and the highway scenario.
32

Identifikace progresivních trendů v městských dopravních systémech v Liberci, Brně, Plzni, Ostravě a Bratislavě / Identifying progressive trends in urban transport in Liberec, Brno, Plzen, Ostrava and Bratislava

Weissova, Zuzana January 2015 (has links)
In theoretical part concept of Smart Cities and urban mass transportation is introduced. Analysis starts with city s approach to strategic documents in transportation (Sustainable Urban Mobility Plans) and their performing in compliance with Smart City concept. Integration of urban transport to integrated transport system is also analysed. Next part describes innovations which are useful for passengers and electronic ticketing systems. Goal is to identify these innovative trends and benchmark success in their introduction in chosen cities. Sources are both public (strategic documents, annual reports) and internal (data from companies).
33

Mezinárodní železniční přeprava zboží v České a Slovenské republice / International railway transport of goods in the Czech Republic and Slovakia

Asman, Tomáš January 2009 (has links)
The goal of my thesis is to analyze the current situation in the market of rail freight transport and to find the potential of the international railway transport of goods in the Czech Republic and Slovakia. It is focused on the comparison of these countries. Main topics of this thesis are i. a. the competitive environment in the Czech and Slovak railway, combined transport, system trains and the expected future progress.
34

Vlaková doprava v integrovaných dopravních systémech / Role of trains in integrated transport systems

Vrbík, Ivo January 2010 (has links)
The objective of this work is focused on trains and their role in integrated transport systems. The functionality of public train transport is shown on 2 most developped integrated systems in Czech republic. My work include comparison of these 2 systems and the role of trains in both of them.
35

Integrovaný dopravní systém v Jihočeském kraji / The Integrated Transport System in the South Bohemian Region

Matoušková, Aneta January 2015 (has links)
This This Master´s Thesis deals with the problems of the integrated transport system in the South Bohemian Region. After the explanation of the concept the integrated transport system follows the specification of the transport systems, the transport divisions and short introduction with the legislative framework. Further in my Master´s thesis I describe two chosen efficient and sophisticated integrated transport systems in the Czech Republic. Next part of this work deals with the current traffic situation in the South Bohemian Region. It follows the prices comparison for the tickets in the local transport and analysis the connection in chosen towns in the South Bohemian Region. The aim of this work is to make a suggestion of the integrated transport system, chose the model, tariffs and prices for the tickets. In the last part of this work I pay attention to the detected weaknesses and I suggest their possible solution.
36

Napojení města Hradce Králové na nadřazený dopravní systém / Connection of the city Hradec Králové to the superior transport system

Burdová, Martina January 2011 (has links)
The aim of this thesis is to describe and evaluate current road transport conditions in Hradec Králové. Next, this paper explains planned constructions in detail and then evaluates benefits of their implementation for the city. In the theoretical part, terms connecting with the road transportation are described. In the practical part, there are the most important roads discussed. Then the author suggests the effect from connecting all mentioned roads to traffic system of Hradec Králové and assess impact for the region. There is also the swot analysis included to evaluate current conditions of road transport in Hradec Králové.
37

Switch a BRT terminal as change generator at Pretoria Main Station

Hugo, Jan Marais 09 December 2010 (has links)
The study responds to the increasing effect that climate change has on earth and society. In a global context of rapid urbanization and population growth the project aims to establish the role that architecture can play in the mitigation of climate change. It addresses the embodied energy and carbon footprint of architecture in an urban context. The architectural building type that will be investigated is a transport interchange, specifically the BRT terminal at Pretoria Main Station and associated prototypical BRT stations. An architectural response that promotes public transport use will be investigated. The proposed transport interchange will act as a seam to linking Salvokop with the city, while linking the whole of Tshwane. The architectural intervention will use strategies to respond to predicted climate changes for Tshwane, and adopt strategies to mitigate it. Architectural technologies will be investigated to ensure that the structure has a low carbon footprint and low embodied energy. Through energy conscious design strategies the energy use of the structure will be kept to a minimum. The design will also address the social and historical context of the Pretoria Main Station, to ensure a coherent transport interchange that integrates all modes of transport. The design will contribute to the historical character of the site with an ecosystemic layered approach, adding new functions and layers to the existing, to ensure its adaptability and sustainability. This study forms the part of a departmental research study through the department of Architecture at Pretoria University - “Environmental potential” and the United Nations Development Programme [UNDP] and Global Environment Facility [GEF]. It aims to comply with the prerequisites for an M[Prof]Arch degree while achieving the goals and objectives set by the research study. / Dissertation (MArch(Prof))--University of Pretoria, 2010. / Architecture / unrestricted
38

Contribution à la modélisation des applications temps réel d'aide à la conduite / Contribution to the modelling of real time advanced assistance systems

Marouane, Hela 16 October 2015 (has links)
Les systèmes d'aide à la conduite gèrent un grand volume de données qui doivent être mises à jour régulièrement. Cependant, ces systèmes ne permettent, ni de les stocker, ni de les gérer d'une manière efficace. Pour ces raisons, nous proposons l'intégration d'un système de bases de données temps réel (TR) dans les systèmes d'aide à la conduite. Cela permet d'améliorer la tolérance aux fautes, de réduire le nombre de transactions et de réduire leur temps de réponse. La gestion d'un grand volume de données et leurs contraintes TR rend ces systèmes plus complexes, ce qui rend leur modélisation plus difficile. Pour remédier à cette complexité, nous avons proposé trois patrons de conception en nous basant sur un processus de création de patrons. Ce processus permet de définir les étapes à suivre pour déterminer les fonctionnalités et les exigences du domaine d'aide à la conduite, d'une part, et de définir les règles d'unification pour générer les diagrammes UML de classes et de séquence, d'autre part. Pour représenter ces patrons, nous avons proposé le profil UML-RTDB2, pour tenir compte : (i) de l'expression de la variabilité des patrons, (ii) de la représentation des contraintes TR et des aspects non fonctionnels et (iii) des éléments instanciés à partir des patrons lors de la modélisation d'une application cible. Une fois les patrons créés, ils peuvent être réutilisés par les concepteurs pour modéliser des systèmes spécifiques. Pour cela, nous avons proposé un processus de réutilisation pour guider les concepteurs d'applications lors de la réutilisation des solutions de patrons. Enfin, nous avons procédé à l'évaluation de ces patrons en utilisant deux catégories de métriques. / Advanced Driver Assistance Systems (ADAS) manage an important volume of data that must be updated regularly. However, ADAS don't store, nor manage efficiently these data. For these reasons, we propose to integrate a real-time (RT) database system into ADAS. The integration of the RT database system allows improving the fault tolerance, reducing the number of transactions and minimizing their response time. The management of a lot of data makes these systems complex, thus, their design is highly difficult. To tackle this problem, we have proposed three patterns based on the pattern development process. This process allows defining the steps to follow in order to determine the functionalities and the requirements of the driver assistance domain on one hand, and defining the unification rules for the generation of the UML class and sequence diagrams, on the other hand. In order to represent these patterns, we have proposed UML-RTDB2 profile, which allows (i) expressing the variability of patterns, (ii) representing the real time constraints and the non functional properties and (iii) identifying the role played by each pattern element in a pattern instance. Once the proposed patterns are created, they can be reused by designers to model a specific application. For this reason, we have proposed a process to assist the applications designers when instantiating the patterns solutions. Finally, we have evaluated these patterns based on two categories of metrics.
39

Symmetric solid target transport system

Tomov, D., Lawrence, L., Gaehle, G. January 2015 (has links)
Introduction The expansion of our PET isotope production with a new TR-19 cyclotron necessitated a suitable solid target transport system. None of the known existing and proposed solid target transport systems (STTS) was able to meet the technical and budget requirements of the MIR cyclotron facility [5]. A unique carrier design allowed us to develop a fully automated 50.8 mm inner diameter pneumatic tube STTS with an in-hot-cell compact form factor receiving station. The cyclotron or vault side loading station is a mere vertically symmetric version of the in-hot-cell station. The carrier is able to accommodate any of our inhouse developed 86Y, 64Cu, 76Br, 89Zr and 99mTc target holders without further modifications. Material and Methods Technical constraints were imposed by the dimensions of the target holders (FIG. 1) and the overall station size (FIG. 3). A receiving station would be inside a hot cell and, up to three sending stations would be located in the confined vault space under the solid target irradiation units. In addition, safety and budget requirements demanded a fully automated, easy to maintain STTS. The target holders are of various geometries with the 99mTc having the maximum dimension of 46.65 mm along its diagonal. Pseudo carriers with diameters ranging from 41 to 49.5 mm (no wear band) and lengths from 50.8 to 102 mm were tested on 50.8 mm inner diameter Kuriyama Tigerflex™ and Goodyear Nutriflex™ tubing. Smaller diameter and length test samples became wobbly, slow, and were getting stuck on occasion. Lengths in the upper limits became stuck in turns with radii close to the minimum radius of the tubing. The necessary negative pressure was achieved by employing a 2.5pHP Ridgid WD06250 blower. The transparent Goodyear Nutriflex™ tubing was chosen for the further STTS development. A carrier capable of loading and unloading regardless of its axial orientation was constructed. This novel design allows for a relatively compact station W 112 × H 220 × L 300, which reduce the dependence on the location of the tube openings in the walls of the hot cell (BqSv, Taiwan). As a result the station can be conveniently placed in areas not typically occupied by processing modules or used by chemists, e.g. close to the upper left corner. To avoid reliance on expensive proprietary parts, all components were designed or chosen to insure reliability with minimal maintenance. The enclosure and opening mechanism are 3D-printable using ABS plastic, and can be made in-house on demand. “Platform sharing” between hot cell and vault stations further simplifies support and maintenance. As with the mechanical hardware, the electronic components and boards were selected to minimize the dependency on a single supplier. The main controller board is based on Atmel\'s AVR series of microcontrollers, which are known to be largely backward compatible, well documented and have an extensive user support base. A single “brick” controls up to three stations. Bricks can be daisy chained with one functioning as a master. The control software takes advantage of the rapid development capabilities of National Instrument\'s LabView graphical language. It is intended to work on Unix-like and Windows operating systems as well as to allow control from hand-held devices. Password security, interlocks and traceability follow the accepted safety standards for radioisotope handling. Results and Conclusion The Symmetric STTS has proven characteristics of reliability, ease of use and safety over hundreds of runs. Given that no convenient carting path exists, it is the ideal means for bringing solid target holders from the underground cyclotron vault to the chemistry processing hot cells at ground level. Transported activities are less than 37.0 GBq (1.0 Ci) for 64Cu and 3.7 GBq (100 mCi) for 89Zr. Carrier velocity is about 4.7m/s minimizing the time activity is present between cyclotron and hot cell. No human interaction with the irradiated target is needed during transport. The carrier does not need to be taken out of the STTS. Even though the BqSv hot cells are equipped with teletongs, they are not needed to recover the target when it arrives at the hot cell; the target is directly dropped into the processing module, e.g. the dissolution vessel for 64Cu processing. The software is engineered in a manner that gives the operator full control of the states of the sending and receiving stations. At the same time, it avoids graphically dense and overloaded GUI in order to reduce the probability of human error. Currently the control program runs on a PC/Laptop and communicates with the controller over USB. LabView provides add-ons that allow control with a tablet or other hand-held (under development). The fully automated symmetric STTS is ideal for isotope production facilities that are being envisioned, conceptualized or are in their planning stage. Its versatility, low initial and operating costs might even justify deployment in facilities which already employ a less optimal solid target transport. Invention application for the Symmetric STTS was filed with the Office of Technology Management of Washington University in Saint Louis, Missouri, USA.
40

Prospects of a sustainable transport system : the case of Stockholm Royal Seaport in 2030. Scenarios of travel behaviour and technological change for a fossil fuel free transport system

Rytterbro, Jon January 2011 (has links)
The transport system is acknowledged as one of the most difficult sectors for sustainable development today. Stockholm Royal Seaport has expressed the ambitious target of developing a fossil free transport system by 2030. This report evaluates several individual measures for carbon dioxide emission reductions and thereafter uses the backcasting approach to investigate how the combination of these can meet the target for the transport system. The results show that a broad range of measures, regarding both behaviour change and technological systems, must be implemented to their maximal potential for the target to be realised.

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