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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.
991

Conception et évaluation d'un modèle adaptatif pour la qualité de service dans les réseaux MPLS

Abboud, Khodor 20 December 2010 (has links) (PDF)
L'objectif de ce travail de thèse dans un premier temps est l'évaluation de performances des modèles de routage multi-chemins pour l'ingénierie de trafic et l'équilibrage de charge sur un réseau de type IP/MPLS (MPLS-TE). Nous comparons la capacité de ces modèles à équilibrer la charge du réseau tout en faisant de la différentiation de trafic. Nous les appliquons sur des grandes topologies générées par le générateur automatique des topologies BRITE, qui s'approchent en forme et en complexité du réseau réel. Nous mesurons ainsi l'impact de leur complexité respective et donc la capacité à les déployer sur des réseaux de grande taille (scalabilité). Dans un second temps, l'objectif est de proposer un concept de modélisation générale d'un réseau à commutations par paquets. Ce modèle est établi sur la base de la théorie différentielle de trafic et la théorie des files d'attente, tout en utilisant des approches graphiques. Le but est d'estimer l'état de charge du réseau et de ses composants (routeurs, liens, chemins). Ensuite, en fonction de ça, nous développons des approches de contrôle de congestion et commande sur l'entrée améliorant les techniques de routage adaptatif et l'équilibrage de charge dans les réseaux IP/MPLS
992

Technologies and design methods for a highly integrated AIS transponder / Teknologier och design metoder för en högintegrerad AIS transponder

Ramquist, Henrik January 2003 (has links)
<p>The principle of universal shipborne automatic identification system (AIS) is to allow automatic exchange of shipboard information between one vessel and another. Saab TransponderTech AB has an operating AIS transponder on the market and the purpose of this report is to investigate alternative technologies that could result in a highly integrated replacement for the existing hardware. </p><p>Design aspects of a system-on-chip are discussed, such as: available system-on- chip technologies, intellectual property, on-chip bus structures and development tools. This information is applied to the existing hardware and the integration possibilities of the various parts of the AIS transponder is investigated. </p><p>The focus will be on two main transponder parts that are possible to replace with highly integrated circuits. The first of these parts is the so-called digital part where system-on-chip platforms for different technologies have been investigated with a special interest in a highly integrated FPGA implementation. The second part is the radio frequency receivers where alternatives to the existing superheterodyne receiver are discussed. </p><p>The conclusion drawn is that there exist technologies for developing a highly integrated AIS transponder. An attractive highly integrated transponder could consist of a FPGA system-on-chip platform with subsampling digital receivers and additional components that are unsuitable for integration.</p>
993

Analysis and implementation of a call simulator for Mobile@Home at Ericsson AB / Analys och implementering av en samtalssimulator för Mobile@Home, Ericsson AB

Larsson, Rasmus, Wikström, Edvard January 2004 (has links)
<p>Mobile telephony technology like GSM made portable telephony a possibility. The arising and development of the Internet made a revolutionary change to communication and interchange of information. Bluetooth wireless technology revolutionizes personal connectivity by providing freedom from wired connections. Combining these technologies together brings the concept of Mobile@Home of Ericsson. </p><p>Mobile@Home is a fixed-mobile convergence concept using the fixed network to carry present and future mobile services (e.g. voice, video, mail and Internet access) all the way to the home or office. By combining the high bandwidth of the fixed access network with the wireless technology of Bluetooth, Mobile@Home makes it possible to deliver high bandwidth to the mobile phone. Mobile@Home requires a Bluetooth enabled mobile phone and a Bluetooth enabled HBS (Home Base Station), placed at the home or office. By means of fast IP access (ADSL, cable modem etc.) the HBS connects into the standard mobile core network through a HBSC (Home Base Station Controller). </p><p>The purpose of this thesis is the generation of simulated traffic between the HBS and HBSC and to analyze its behavior. This primary involves generation of signaling through an internal protocol, provided by Ericsson, for management and call control, and generation of GSM EFR (Enhanced Full Rate) voice streams over the RTP (Real Time Protocol) protocol. The simulation will consist of both the HBS and MS (Mobile Station). A set of HBS: s with attached MS will call one another through the HBSC. In this assignment only the GSM signaling will be considered because of time and scope limitations. The goal is to validate the RTP traffic generated towards the HBSC. Parameters like packet loss, packet delay and erroneous packets will be analyzed.</p>
994

Informationskällor under internationalisering : Svenska små företags tillvägagångssätt för att tillägna sig kunskap och information / « Les sources d’information pendant le procesus d’internalization »

Nasri, Maryem January 2005 (has links)
<p>There is an ongoing process where the free market within the European Union is expanding, partly through the incorporation of new member states, partly through the signing of association agreements with nearby countries and regions. When trade barriers are removed in different ways more companies consider an internationalization of the company. However, the procedure of the internationalization of companies is a rather new and unexplored area in the context of research. The focus of this study is therefore to examine how a few companies situated in Sweden, has proceeded while searching for knowledge during the internationalization process. Data has been collected through interviews that have been balanced with information from Internet and other sources. The tools that has been used to analyze is first and foremost the Uppsala model of the internationalization process, but common principles, emerged from studies at Södertörns Högskola, Stockholm, and Universitat Pompeu Fabra, Barcelona, has also been used. During the study the importance of personal contacts has come to light as well as the lack of research of the strategies of immigrant enterprises.</p>
995

Propuesta de migración de la red NGN de una operadora implementada en IP hacia MPLS / Giancarlo García Girón.

García Girón, Giancarlo. 09 May 2011 (has links)
La presente tesis consiste en brindar una propuesta técnica para la migración del core de la red NGN de una operadora implementada en IP hacia IPMPLS. Durante el desarrollo de este proyecto se presenta el marco teórico de las redes NGN y se realiza la comparación entre las tecnologías IP y MPLS con el objetivo de observar las ventajas que presenta MPLS al brindar QoS. Luego, se presenta la Propuesta de migración en la cual se presenta el escenario inicial así como los aspectos técnicos, plan de trabajo y el escenario final de la migración. Por último, se detallan las conclusiones obtenidas al final de este proyecto, recomendaciones y trabajos futuros.
996

FPGA-Based Real-Time Simulation of Variable Speed AC Drive

Myaing, Aung 11 1900 (has links)
Sophisticated power electronic apparatus and their digital control systems are finding increasing applications in electric power systems at generation, transmission, distribution and utilization levels. It is essential to carry out rigorous performance evaluation of such apparatus before commissioning. Field Programmable Gate Arrays (FPGAs) are becoming an attractive platform for accelerating computationally intensive applications. This thesis presents a FPGA-based real-time digital simulator for power electronic drives based on realistic device characteristics. A 3-level 12-pulse Voltage Source Converter (VSC) fed induction machine drive is implemented on the FPGA. The system components include the 3-level VSC, the induction machine, the direct field oriented controller, and the pulse width modulator. Both system-level and device-level IGBT models are utilized to implement the VSC. The VSC model is computed at a fixed time-step of 12:5ns allowing an accurate representation of the IGBT nonlinear switching characteristics. Altera Startix EP1S80 and EP3SL150F1152C2 FPGA boards utilized for the real-time simulation. All models were implemented in VHDL. The FPGA boards were interfaced to external DAC boards to display real-time results on the oscilloscope. The real-time results were validated using an off-line cosimulation set-up using the SABER and MATLAB/SIMULINK software. / Power Engineering and Power Electronics
997

Informationskällor under internationalisering : Svenska små företags tillvägagångssätt för att tillägna sig kunskap och information / « Les sources d’information pendant le procesus d’internalization »

Nasri, Maryem January 2005 (has links)
There is an ongoing process where the free market within the European Union is expanding, partly through the incorporation of new member states, partly through the signing of association agreements with nearby countries and regions. When trade barriers are removed in different ways more companies consider an internationalization of the company. However, the procedure of the internationalization of companies is a rather new and unexplored area in the context of research. The focus of this study is therefore to examine how a few companies situated in Sweden, has proceeded while searching for knowledge during the internationalization process. Data has been collected through interviews that have been balanced with information from Internet and other sources. The tools that has been used to analyze is first and foremost the Uppsala model of the internationalization process, but common principles, emerged from studies at Södertörns Högskola, Stockholm, and Universitat Pompeu Fabra, Barcelona, has also been used. During the study the importance of personal contacts has come to light as well as the lack of research of the strategies of immigrant enterprises.
998

Integration of heterogeneous wireless access networks with IP multimedia subsystem

Peyman, Talebifard 05 1900 (has links)
Next generation heterogeneous wireless networks are expected to interwork with Internet Protocol (IP)-based infrastructures. Conventional network services operate like silos in that a specific set of services are offered over a specific type of access network. As access networks evolve to provide IP-based packet access, it becomes attractive to break these “service silos” by offering a converged set of IP-based services to users who may access these services using a number of alternative access networks. This trend has started with third generation cellular mobile networks, which have standardized on the use of the IP Multimedia Subsystem (IMS) to manage user access to a wide variety of multimedia services over the mobile Internet, while facilitating interworking of heterogeneous wireless and landline access networks. The future users of communication systems will subscribe to both IP-based and Circuit Switched (CS) based services and in the foreseeable future a single database that handles user profiles across all domains will be required. Home Subscriber Server (HSS) as an evolved version of Home Location Register (HLR) is one of the key components of IMS. In deploying HSS as a central repository database, in a fully overlapped heterogeneous network setting, changes of access mode are very frequent and conveying this information to HSS imposes excessive signaling load and delay. In our proposed scheme we introduce an Interface Agent (IA) for each location area that caches the location and information about the access mode through which a user can be reached. This method results in significant amount of savings in signaling cost and better delay performance. The existing call delivery approaches in cellular networks may not be well suited for future communication systems because they suffer from unnecessary usage of network resources for call attempts that may fail which adds to excessive signaling delays and queuing costs. Reducing the number of queries and retrievals from the database will have a significant impact on the network performance. We present a new scheme based on Reverse Virtual Call setup (RVC) as a solution to the call delivery problem in heterogeneous wireless networks and evaluate the performance of this framework.
999

Charakterisierung der mitochondrialen Außenmembranproteine Om14p und Om45p von Saccharomyces cerevisiae

Lauffer, Heidemarie Susann 04 July 2013 (has links) (PDF)
Aufgrund der vielfältigen metabolischen Prozesse und Funktionen von Mitochondrien finden durch beide mitochondriale Membranen zahlreiche Transportprozesse statt. Es wird weitgehend angenommen, dass der Transfer von metabolischen Intermediaten durch die äußere Membran von den zahlreichen Porinporen gewährleistet wird. Im Gegensatz dazu sind in der inneren Membran spezifische Transportproteine für die Translokationsprozesse verantwortlich. Neben dem gut untersuchten Porinmolekül (Por1p) gibt es in der Hefe S. cerevisiae unter respiratorischen Bedingungen zwei weitere abundante, aber funktionell unbekannte Proteine in der äußeren Membran von Mitochondrien - Om14p und Om45p -, deren molekular-biologische Charakterisierung Gegenstand dieser Arbeit war. Mit drei unabhängigen Methoden (2D BN - SDS-PAGE, Co-IP und TAP) konnte gezeigt werden, dass die beiden Proteine Om14p und Om45p zusammen mit Por1p einen Proteinkomplex in der äußeren Membran ausbilden, wobei Por1p eine von Om14p und Om45p unabhängige Porenstruktur ausbildet. Bei Bedarf, möglicherweise über Phosphorylierungen signalisiert, binden Om14p und Om45p an diese Struktur, wobei Om45p dabei der direkten Interaktion von Om14p mit Por1p bedarf. Die Identifikation von Interaktionspartnern des Fusionsproteins Om14p-TAP durch Einsatz einer präparativen TAP mit anschließender massenspektrometrischer Analyse sowie die Untersuchungen der Effekte von OM14- und/oder OM45- Gendeletionen auf das mitochondriale Proteom mit einem 2D DIGE-Verfahren führten zur Aufstellung von funktionalen Zusammenhängen des Proteinpaares Om14p/Om45p. Mit Wachstumsuntersuchungen von Deletionsmutanten in Gegenwart von in den Mitochondrien toxisch wirkenden Substanzen sowie durch ein in dieser Arbeit entwickeltes Testverfahren zur Bestimmung des mitochondrialen ATP-Flusses, konnten die funktionalen Hypothesen für die Proteine Om14p und Om45p initial verifiziert werden. Zusammengefasst unterstützen die Daten dieser Arbeit die Idee von einem hochgradig flexiblen System der Mitochondrien, zur Gewährleistung von effizienten Transportvorgängen durch beide Membranen. Eine koordinierte Bindung der Porinpore an die spezifischen Transporter der inneren Membran wird wahrscheinlich durch die Aktivität des Proteinpaares Om14p/Om45p vermittelt. In diesem Zusammenhang könnten beide Proteine als eine Art Lizenzierungsfaktor fungieren und die Positionierung der Porinpore an die entsprechenden Proteine der inneren Membran erzeugen. Dadurch würde ein effektives System für den Austausch von metabolischen Intermediaten und Substraten der mitochondrialen Atmungskette entstehen. Ebenfalls durch diese Arbeit nicht auszuschließen ist die Vorstellung, dass die Proteine Om14p und Om45p einen Einfluss auf die spezifischen Transportproteine der inneren Membran oder die Porinpore der äußeren Membran ausüben. Phosphatrest-Übertragungen, die zu Konformationsänderungen oder Porenöffnungen führen könnten, sind beispielsweise vorstellbar. Die Stoffwechseladaption einer Zelle bei einem diauxic shift ist durch einen verstärkten mitochondrialen Import von Metaboliten, Co-Faktoren und Proteinen sowie häufigerer mitochondrialer Teilungsprozesse charakterisiert. Om14p und Om45p sind bei einem Wechsel zu nicht-fermentativen Bedingungen verstärkt präsent. Diese beiden Proteine könnten der Hefe einen entscheidenden Vorteil bei der Synchronisierung der genannten Prozesse liefern, indem sie eine verbesserte Erreichbarkeit bzw. eine Veränderung der Selektivität von bereitgestellten Kanälen bzw. Transportproteinen in beiden mitochondrialen Membranen bewirken.
1000

Developing a Communication link between Agents and cross Platform IDE

AAMIR, ZEESHAN January 2010 (has links)
The main objective of this thesis work is to develop communication link between Runrev Revolution (IDE) and JADE (Multi-Agent System) through Socket programming using TCP/IP layer. These two independent platforms are connected using socket programming technique. Socket programming is considered to be newly emerging technology among these two platforms, the work done in this thesis work is considered to be a prototype.A Graphical simulation model is developed by salixphere (Company in Hedemora) to simulate logistic problems using Runrev Revolution (IDE). The simulation software/program is called “BIOSIM”. The logistic problems are complex, and conventional optimization techniques are unlikely very successful. “BIOSIM” can demonstrate the graphical representation of logistic problems depending upon the problem domains. As this simulation model is developed in revolution programming language (Transcript) which is dynamically typed and English-like language, it is quite slow compared to other high level programming languages. The object of this thesis work is to add intelligent behaviour in graphical objects and develop communication link between Runrev revolution (IDE) and JADE (Multi-Agent System) using TCP/IP layers.The test shows the intelligent behaviour in the graphical objects and successful communication between Runrev Revolution (IDE) and JADE (Multi-Agent System).

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