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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.
941

Highly variable real-time networks: an Ethernet/IP solution and application to railway trains

Constantopoulos, Vassilios 03 July 2006 (has links)
In this thesis we study the key requirements and solutions for the feasibility and application of Ethernet-TCP/IP technology to the networks we termed Highly-Variable Real-Time Networks (HVRN). This particular class of networks poses exceptionally demanding requirements because their physical and logical topologies are both temporally and spatially variable. We devised and introduced specific mechanisms for applying Ethernet-TCP/IP to HVRNs with particular emphasis on effective and reliable modular connectivity. Using a railroad train as a reference, this work analyzes the unique requirements of HVRNs and focuses on the backbone architecture for such a system under Ethernet and TCP/IP. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
942

IMPLEMENTAÇÃO DE ARQUITETURAS DE PILHA UDP/IP EM HARDWARE RECONFIGURÁVEL BASEADO NO DESEMPENHO DE VAZÃO, LATÊNCIA E TAXA DE PERDA DE QUADROS / IMPLEMENTATION OF UDP/IP STACK ARCHITECTURES IN RECONFIGURABLE HARDWARE BASED ON THROUGHPUT, LATENCY AND FRAME LOSS RATE PERFORMANCE

Herrmann, Fernando Luís 11 March 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work presents the implementation of three architectures of UDP/IP network stack in reconfigurable hardware. Also, presents the development of a Tester based on the RFC 2544 methodology and implemented it in FPGA. This Tester was used to obtain the throughput, latency and frame loss rate results. The performance of the project shows, in average, throughput results 89% better in comparison with a network stack implemented in software (PC) and running over a general purpose microprocessor, for frames with 64 bytes. Regarding latency, the project is 389 times lower for frames with 64 bytes and 13 times lower for frames with 1518 bytes, than the PC. On behalf of frame loss rate, the project doesn t loss frames for any frame sizes used during the tests, while the PC has presented a frame loss of almost 98% for frames with 64 bytes. / Este trabalho apresenta a implementação de três arquiteturas da pilha de comunicação UDP/IP em hardware reconfigurável. Também apresenta o desenvolvimento de um Testador baseado na metodologia da RFC 2544 e implementado em uma placa dotada de dispositivo FPGA. Esse Testador foi utilizado na obtenção dos resultados de vazão, latência e taxa de perda de quadros. O desempenho do projeto apresentou, em média, 89% a mais de vazão, para quadros de 64 bytes, que uma pilha de comunicação implementada em software (PC) e executada sobre um microprocessador de propósito geral. Em termos de latência, o projeto apresentou uma latência 389 vezes menor para quadros de 64 bytes e 13 vezes menor para quadros de 1518 bytes, que o PC. E em relação à taxa de perda de quadros, o projeto não apresentou perda para nenhum dos tamanhos de quadros utilizados durante os testes, enquanto o PC apresentou perda de quase 98% para quadros de 64 bytes.
943

Etude de la variabilité génétique des régions NS3, NS5A et NS5B du virus de l'hépatite C chez des patients Tunisiens non traités / Genetic variability of NS3, NS5A and NS5B regions of hepatitis C virus in Tunisians naïve-patients

Aissa Larousse, Jameleddine 22 December 2015 (has links)
Introduction : Le virus de l’hépatite C (VHC), est l’une des premières causes de pathologie hépatique dans le monde. Ce virus à ARN est responsable de l’hépatite C qui aboutit au développement de la cirrhose et du cancer du foie. Selon l’Organisation Mondiale de la Santé, le VHC infecte actuellement plus de 170 millions de personnes dans le monde, soit 3% de la population. L’hépatite C chronique connait toujours en Tunisie un taux de guérison faible pour le génotype 1 car le traitement standard actuellement disponible est la bithérapie interféron pégylé associé à la ribavirine. A l’heure actuelle, le développement de différentes molécules ciblant spécifiquement le VHC, appelées les antiviraux à action directe (AAD), apparait comme une potentielle révolution dans le traitement de l’infection par le VHC.Ces AAD comprennent les inhibiteurs de protéase (IP), les inhibiteurs nucléos(t)idiques (IN) et les inhibiteurs non-nucléosidiques (INN) de la polymérase NS5B ainsi que les inhibiteurs de la protéine NS5A. La quasi-espèce virale est formée d’un mélange complexe de variants viraux parmi lesquels se trouvent des variants associés à des degrés variables à la résistance aux AAD. Ces variants peuvent donc exister naturellement en absence de toute pression médicamenteuse et sont susceptibles d’avoir un impact sur la réponse aux différents traitements par AAD. Notre objectif était de déterminer la prévalence des variants associés à la résistance dans les souches tunisiennes circulantes en préambule à l’introduction deces molécules en Tunisie. Méthodes : L’amplification et le séquençage direct de la protéase NS3, de la polymérase NS5B ainsi que la région NS5A ont été effectuées chez 149 patients tunisiens naïfs de traitement et infectés par le VHC de génotype 1 (génotype 1b = 142 ; génotype 1a = 7). Résultats : Douze séquences NS3 (12/131 ; 9,2%) ont montré des mutations connes pour conférer une résistance aux IP. Une seule séquence (1/95 ; 1,1%) a montré la mutation V321I connue pour conférer une résistance aux IN-NS5B. Trente quatre séquences (34/95 ; 35,8%) ont montré des mutations connues pour diminuer la sensibilité des INN-NS5B. Une seule séquence de génotype 1a (1/7 ; 14,3%) et 17 séquences de génotype 1b (17/112 ; 16,2%) ont montré des mutations connues pour conférer une résistance au inhibiteurs de la protéine NS5A. Conclusions : Notre étude a permis de mettre en évidence la présence de substitutions conférant une diminution de la sensibilité aux AAD chez des patients tunisiens naïfs de tout traitement anti-VHC. Des études in situ seront nécessaires pour évaluer l’impact de ces mutations sur la réponse au traitement. / Introduction: Hepatitis C virus (HCV) is a major cause of liver disease worldwide. This RNA virus is responsible for hepatitis C, which leads to the development of cirrhosis and liver cancer. According to the World Health Organization, HCV infects more than 170 million people worldwide, about 3% of the population. Chronic hepatitis C still know in Tunisia low cure rates for genotype 1, because the currently standard treatment available is combination therapy of pegylated interferon plus ribavirin. At present, the development of different molecules that specifically target HCV, called direct-acting antivirals (DAA) appears as a potential revolution in the treatment of HCV infection. These DAA include protease inhibitors (PI), nucleos(t)ide (NI) and non-nucleoside inhibitors (NNI) for NS5B polymerase and NS5A inhibitors. The viral quasispecies is formed by a complex mixture of viral variants including variants associated with variable degrees of resistance to DAA. These variants may therefore exist naturally in absence of drug pressure and may affect response to different treatments by DAA. Our objective was to determine the prevalence of variants associated with resistance in circulating Tunisian strains preamble to the introduction of these molecules in Tunisia. Methods: Amplification and direct sequencing of NS3 protease, NS5B polymerase and NS5A region were performed in 149 Tunisian naïve patients infected with HCV genotype 1 (genotype 1b = 142; genotype 1a = 7) . Results: Twelve sequences NS3 (12/131; 9.2%) showed mutations known to confer resistance to PI. One sequence (1/95; 1.1%) showed the V321I mutation known to confer resistance to NS5B-IN. Thirty four sequences (34/95; 35.8%) showed mutations known to reduce the sensitivity of NS5B-INN. One genotype 1a sequence (1/7; 14.3%) and 17 genotype 1b sequences (17/112; 16.2%) showed mutations known to confer resistance to NS5A inhibitors.Conclusions: Our study highlighted the presence of substitutions conferring decreased susceptibility to DAA in naïve patients infected with HCV genotype 1. Field studies will be needed to evaluate the impact of these mutations on the treatment response.
944

Um medidor de energia elétrica integrado em redes de comunicações / An electricity power meter integrated into communications networks

Cesário Júnior, José Maria, 1979- 24 August 2018 (has links)
Orientadores: Varese Salvador Timóteo, Francisco José Arnold / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-24T09:10:01Z (GMT). No. of bitstreams: 1 CesarioJunior_JoseMaria_M.pdf: 2596300 bytes, checksum: 6b11eb547957a0632bbc647946da04ce (MD5) Previous issue date: 2014 / Resumo: A crescente evolução mundial dos sistemas de medição inteligentes, a liberação de regulamentações Brasileiras, incentivando a adoção de sistemas de medição de energia elétrica inteligentes, direcionaram a presente dissertação a propor um sistema composto de um equipamento eletrônico para medição, em tempo real, das grandezas de corrente, tensão e calcular a energia consumida e terá canais de comunicação com as tecnologias Wi-Fi, GSM/GPRS e GPS. As informações sobre consumo serão disponibilizadas para os usuários finais com o objetivo de mudar o padrão de consumo de energia elétrica, ou até reduzi-lo, através da conscientização e disponibilização das informações de consumo em tempo real / Abstract: The growing worldwide trend of smart metering systems, the release of Brazilian regulations, encouraging the adoption of smart electricity metering systems, guided this dissertation to propose a system composed of an electronic device for measuring, in real time, the magnitudes of current, voltage and calculate the consumed power and will have communication channels based on Wi-Fi, GSM /GPRS and GPS technologies. The consumption information will be made available to end users with the goal of changing the electricity consumption pattern, or even reduce it, through awareness and provision of consumer information in real time / Mestrado / Tecnologia e Inovação / Mestre em Tecnologia
945

Conceito e dimensionamento de recursos de voz e sinalização em redes de nova geração / Concept and dimensioning of voice and signaling resources in next generation networks

Silveira, Loreno Menezes da, 1952- 04 October 2015 (has links)
Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T09:49:57Z (GMT). No. of bitstreams: 1 Silveira_LorenoMenezesda_M.pdf: 2626161 bytes, checksum: b80454b10dc90baf554cb0f37c6ba67e (MD5) Previous issue date: 2015 / Resumo: Esta dissertação apresenta uma visão da evolução das redes de telecomunicações objetivando o atendimento dos parâmetros da Qualidade de Serviço de redes IP aos requisitos de qualidade de voz das redes telefônicas de circuitos comutados. Gera também uma série de resultados úteis para planejar a introdução de novas tecnologias e de Redes de Nova Geração (NGN) para serviços de voz. Entre os resultados, introduz uma metodologia de planejamento de rede com base na experiência do autor na área. A aplicação desta metodologia é descrita em um caso de estudo sobre a introdução do serviço de voz através de uma rede IP existente. Analisa parâmetros de qualidade de serviço, requisitos de qualidade de voz e, finalmente, calcula a taxa de transferência de fluxo de dados adicional devido ao tráfego de voz. Os cálculos são baseados em um modelo de dimensionamento implementado em uma planilha do Excel. Apesar de não mostrado neste trabalho, os resultados provaram sua efetividade e consistência com a implantação de uma prestadora específica e com o comportamento subsequente da rede em cidades relevantes, como São Paulo, Rio de Janeiro e Belo Horizontes. A dissertação também apresenta modelos de dimensionamento para o tráfego de sinalização: Sistema de Sinalização Nº 7 (ISUP - Rede Digital de Serviços Integrados e BICC - Portador de Controle de chamada Independent) para uso em redes TDM (Time Division Multiplex), ATM (Asynchronous Transfer Mode) ou NGN, explorando estes modelos de aplicação para o protocolo H.248 com possível extensão a SIP, ambos usados no contexto NGN / Abstract: This dissertation provides an overview of telecommunication networks evolution in the light of compliance of IP networks Quality of Service¿s parameters with Public Switched Telephone Networks (PSTN) voice quality requirements. It also delivers a number of new results useful for planning and designing the introduction of new technologies as well as Next Generation Networks (NGN), to provide voice services. Among the results, it introduces a network planning methodology based on the author's experience in this area. The application of such methodology is depicted in a study case concerning the introduction of the voice service over an existing IP network. It analyzes Quality of Service parameters, voice quality requirements and, finally, it calculates the additional data flow throughput due to the voice traffic. The calculations are based on a dimensioning model implemented in an excel spreadsheet. Although not being shown here, the results have been proved effective and consistent with a specific carrier deployment and subsequent network behavior in relevant cities like São, Paulo, Rio de Janeiro and Belo Horizonte. This work also presents a dimensioning model for signaling traffic: Signalling System Nº 7 (ISUP ¿ Integrated Services Digital Networks and BICC - Bearer Independent Call Control) for use in TDM (Time Division Multiplex), ATM (Asynchronous Transfer Mode) or NGN networks. Furthermore, it exploits the application of the dimensioning model to H.248 protocol, suggesting how to extend it to SIP, both used in the NGN context / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
946

Influência de categorias de riscos nos resultados de projetos de backbone IP / Influence of risk categories on results of IP backbone projects

Genaro, Fábio 27 March 2018 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-09-14T18:01:54Z No. of bitstreams: 1 Fabio Genaro.pdf: 2507994 bytes, checksum: 628164f009c25ca35b1d6712f64aed0b (MD5) / Made available in DSpace on 2018-09-14T18:01:54Z (GMT). No. of bitstreams: 1 Fabio Genaro.pdf: 2507994 bytes, checksum: 628164f009c25ca35b1d6712f64aed0b (MD5) Previous issue date: 2018-03-27 / In the current view of telecommunications providers, the quality and the constant availability of the services offered to the customers are vital for the continuity of the business, thus avoiding withdrawals and gross revenue reductions. For this purpose, technological, financial and human resources are required, which must be invested in the providers’ main traffic services network, which is called IP backbone. Like any project, IP backbone projects do not flee the rule and are also subject to several risks that, if ignored during the kickoff and planning stages, could jeopardize their implementation by telecommunications providers, impacting on their final results, whether strategic or operational. The objective of this dissertation was to analyze the influence of risk categories in IP backbone projects on strategic and operational results in telecommunications providers. The approach of this work was qualitative with multiple case studies, being taken as units of analysis three IP backbone projects of two Brazilian telecommunications providers. The results showed which categories of risk were found and what impacts they can have on strategic and operational results. / Na visão atual das operadoras de telecomunicações, a qualidade e a disponibilidade constante dos serviços ofertados aos clientes são vitais para a continuidade dos negócios, evitando assim desistências e reduções de faturamento bruto. Para esta finalidade, são necessários recursos tecnológicos, financeiros e humanos, os quais devem ser investidos na principal rede de tráfego de serviços da operadora, a qual é denominada de backbone IP. Como todo projeto, os projetos de backbone IP não fogem à regra e também se encontram sujeitos a riscos diversos que, se ignorados durante as etapas de planejamento e kickoff, podem comprometer sua implantação pelas operadoras de telecomunicações, com impactos em seus resultados finais, sejam eles estratégicos ou operacionais. O objetivo desta dissertação foi o de analisar a influência de categorias de riscos em projetos de backbone IP nos resultados estratégicos e operacionais em operadoras de telecomunicações. A abordagem desta dissertação foi qualitativa com estudos de casos múltiplos, sendo tomados como unidades de análise três projetos de backbone IP de duas operadoras nacionais de telecomunicações. Os resultados encontrados mostraram quais categorias de riscos foram encontradas e quais os impactos que elas podem produzir nos resultados estratégicos e operacionais.
947

Forenzní analýza prostředí IoT ze stop síťové komunikace / Forensic Analysis of the IoT Environment from Network Communication Traces

Slámová, Hana January 2021 (has links)
The goal of this master's thesis is a creation of dataset capturing selected users' activities, network analysis of this dataset, design and implementation of method to detect selected users' activities and discussion of achieved results. 4 devices have been chosen for the creation of this dataset.
948

Speciální aplikace VoIP / Special application of VoIP

Lembard, Tomáš January 2011 (has links)
The aim of this master's thesis is suggestion and following realization of voice transmission over the local network equipment and a description of used circuits and solutions in terms of hardware and software. This thesis deals with digitization of low-frequency signals, the structure of IP and UDP protocols, implementation of TCP/IP stack cIPS
949

Implementace ethernetového komunikačního rozhraní do obvodu FPGA / Implementation of ethernet communication inteface into FPGA chip

Skibik, Petr January 2011 (has links)
The thesis deals with the implementation of Ethernet-based network communication interface into FPGA chip. VHDL programming language is used for description of the hardware. The interface includes the implementation of link-layer Ethernet protocol and network protocols such as IPv4, ARP, ICMP and UDP. The final design allows bi-directional communication on the transport-layer level of TCP/IP model. The designed interface was implemented into Virtex5 FPGA chip on development board ML506 by Xilinx.
950

Určení pozice útočníka při pokusu o neoprávněný přístup do operačního systému / Location of attacker attempting unauthorized access to operating system

Pokorný, Josef January 2013 (has links)
My master thesis estimates physical location of potential operating system attacker. It deals with basic methods of attack against operating system: spam and viruses, searching the Internet, port scanning and operating system detection. The thesis disserts about a port scanner Nmap, a port scanning detector Scanlogd and about a system log watch Swatch. The thesis deals with geolocation methods of potential operating system attacker. These geolocation methods are divided into an active and a passive types. The active methods measure delay in the Internet. The passive methods query the database. I mentioned a freely accessible Whois database and MaxMind databases. There is a program developed and practically tested. The program simulates an attacker beginning an attack by scanning ports of target machine. The program works with dataset of real IP addresses. The program also detects the attack against operating system. The real and evaluated location of an attacker is got and then shown in a map. At the end there is a review of results and data comparison with colleagues.

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