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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.
41

Projeto da arquitetura de hardware para binarização e modelagem de contextos para o CABAC do padrão de compressão de vídeo H.264/AVC / Hardware architecture design for binarization and context modeling for CABAC of H.264/AVC video compression

Martins, André Luis Del Mestre January 2011 (has links)
O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.
42

Projeto da arquitetura de hardware para binarização e modelagem de contextos para o CABAC do padrão de compressão de vídeo H.264/AVC / Hardware architecture design for binarization and context modeling for CABAC of H.264/AVC video compression

Martins, André Luis Del Mestre January 2011 (has links)
O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.
43

Homeschooling in Chile. Report National Survey Results / Educación en el hogar en Chile. Informe de resultados de la Encuesta Nacional / Homeschooling no Chile. Relatório de resultados da Pesquisa Nacional

Aliaga Castillo, Lester 10 April 2018 (has links)
In 2014 a survey to gather information about families who practice homeschoolingin Chile took place. They answered 67 families on the reasons that took the valuesthey care, forms of socialization, the sources to develop the curriculum and timemanagement for learning. This work is part of a larger research on home educationin Chile. / En 2014 se realizó una encuesta para levantar información acerca de las familias que practican el homeschooling en Chile. Respondieron 67 familias acerca de los motivos que tuvieron, los valores que les interesa, sus formas de socialización, las fuentes para desarrollar el currículum y la gestión del tiempo para el aprendizaje. Este trabajo forma parte de una investigación mayor acerca de la educación en el hogar en Chile. / Em 2014 uma pesquisa para coletar informações sobre as famílias que praticamHomeschooling no Chile ocorreu. Eles responderam a 67 famílias sobre os motivosque levaram os valores que lhes interessam, formas de socialização, as fontes paradesenvolver o currículo e gerenciamento de tempo para a aprendizagem.Este trabalho é parte de uma pesquisa maior sobre a educação em casa no Chile.
44

An Energy-Efficient Reservation Framework for Large-Scale Distributed Systems / Un environnement de réservation efficace en énergie pour les systèmes distribués à grande échelle

Orgerie, Anne-Cécile 27 September 2011 (has links)
Depuis quelques années, économiser l'énergie est devenu un enjeu majeur dans les technologies de l'information et de la communication (TIC). Celles-ci représentent en effet 2% des émissions de CO2 de la planète, soit autant que l'aviation. Les systèmes distribués (grilles, clouds, réseaux haute performance) constituent de gros consommateurs d'électricité. En effet, pour des besoins de haute disponibilité, leurs ressources sont allumées en permanence et notamment lorsqu'elles ne sont pas utilisées. Les systèmes de réservation garantissent qualité de service et respect des contraintes de l'utilisateur. Ils permettent également une gestion plus fine des ressources. Pour limiter la consommation électrique des systèmes distribués et des réseaux dédiés, nous avons proposé un système de réservation de ressources efficace en énergie. Ce système de réservation, appelé ERIDIS, a été adapté à trois infrastructures distribuées différentes: les centres de calcul et les grilles, les environnements de cloud et les réseaux filaires dédiés. Dans les trois cas, des validations ont été menées et elles ont montré que des économies d'énergie significatives pouvaient être réalisées en utilisant ERIDIS dans les systèmes distribués actuels et futurs. / Over the past few years, the energy consumption of Information and Communication Technologies (ICT) has become a major issue. Nowadays, ICT accounts for 2% of the global CO2 emissions, an amount similar to that produced by the aviation industry. Large-scale distributed systems (e.g. Grids, Clouds and high-performance networks) are often heavy electricity consumers because -- for high-availability requirements -- their resources are always powered on even when they are not in use. Reservation-based systems guarantee quality of service, allow for respect of user constraints and enable fine-grained resource management. For these reasons, we propose an energy-efficient reservation framework to reduce the electric consumption of distributed systems and dedicated networks. The framework, called ERIDIS, is adapted to three different systems: data centers and grids, cloud environments and dedicated wired networks. By validating each derived infrastructure, we show that significant amounts of energy can be saved using ERIDIS in current and future large-scale distributed systems.
45

Optimización de data center móviles para accesibilidad y capacidades de procesamiento en lugares urbanos

Pezo Castañeda, Ronald Paul, De La Cruz Ninapaitan, Steve Jasson, Torres Rozas, Bruno Alexis January 2015 (has links)
Actualmente, los sectores empresariales optimizan sus costos sin perder eficiencia productiva en Data Center Móviles tercer izando el servicio y adquiriendo esta tecnología ya que la infraestructura montada es de utilidad para todo ámbito empresarial. El presente proyecto trata sobre el servicio de implementación de un nuevo Data Center Contingente tipo Container, en adelante CPD, como consecuencia de las necesidades de mejora centro de los procesos de negocio. El diseño y dimensionamiento de los diferentes componentes cumplen los estándares requeridos en el mercado. Los Outdoor Enclosure Electric Shelter Prefabricados en sí y todos los equipamientos eléctricos utilizados en sus sistemas para la protección, control y supervisión, están construidos de acuerdo a las Normas vigentes de ANSI, NEMA, ASTM, IEEE, ISA, OSHA, los cuales además cuentan con Aprobaciones y Certificación de Calidad de Laboratorios como UL, CSA, SEC o Laboratorios de Control de Producción y de Certificación de Calidad equivalentes. Actualmente las empresas vienen usando enlaces propios y dedicados para manejar su información y conexión con su data center principal y de contingencia. En muchos casos desaprovechando la comunicación entre ellos por lo que se requiere la necesidad de ser más efectivos en el uso de sus recursos de comunicación, por lo cual se debe considerar los siguientes aspectos: • Modelamiento de Tráfico. • Seguridad. • Conmutación de enlaces. Currently, the business sectors optimize their costs without losing production efficiency in Mobile Data Center outsourcing service and acquiring this technology because the infrastructure is mounted useful for all business field. This project deals with the service of implementing a new quota type Data Center Container, hereinafter CPD, following needs improvement center business processes. The design and dimensioning of the different components meet the required standards in the market. The Outdoor Enclosure Electric Shelter Prefabricated itself and all electrical equipment used in systems for the protection, control and monitoring are built according to current standards of ANSI, NEMA, ASTM, IEEE, ISA, OSHA, which also have with Approvals and Quality Certification Laboratories as UL, CSA, SEC or Control Laboratories Production and Quality Certification equivalents. Currently companies are using own links and dedicated to manage their information and connection with your main data center and contingency. In many cases missing the communication between them so the need to be more effective in their use of communication resources is required, so you should consider the following: • Traffic Modeling. • Security. • Switching links.
46

Projeto da arquitetura de hardware para binarização e modelagem de contextos para o CABAC do padrão de compressão de vídeo H.264/AVC / Hardware architecture design for binarization and context modeling for CABAC of H.264/AVC video compression

Martins, André Luis Del Mestre January 2011 (has links)
O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.
47

Analysis of Radio Access Network Buffer Filling Based on Real Network Data

Aruchamy, Logabharathi January 2012 (has links)
The 3G and 4G networks have drastically improved availability and quality in data transmission for bandwidth hungry services such as video streaming and location-based services. As 3G networks are very widely deployed, there exists increased capacity requirement and transport channel allocation to simultaneous users under a particular cell. Due to this reason, adequate resources are not available, which in turn degrades both service quality and user experienced quality. This research aims at understanding the characteristics of buffer filling during dedicated channel (DCH) transmission under fixed bit-rate assumptions on a per-user level taking different services into consideration. Furthermore, the resource utilisation in terms of empty buffer durations and user throughput achieved during dedicated channel transmission are also analysed for different data services existing in the mobile networks. The traces are collected from a real network and characteristics of the traffic are analysed prior to understanding its buffer filling in Radio Network Controller (RNC) during downlink data transmission. Furthermore, the buffer is modelled with some series of assumptions on channel bit-rates and simulations are performed taking single user scenario into consideration, for different services with the help of obtained traces as input to the buffer. This research is helpful in understanding the RNC buffer filling for different services, in turn yielding possible understanding on the existing transport channel switching scenario. With the help of analysing the buffer filling for different services and transport channel utilisation, we learn that most of the data services show low DCH utilisation of approximately around 20% and also found to have 80% of the total DCH session duration with empty buffer, causing sub-optimal radio resource utilization.
48

Možnosti zabezpečení mezi-procesorové komunikace pro dedikovaná zařízení / Possibilities of securing inter-processor communication for dedicated devices

Rácek, Luboš January 2016 (has links)
Diploma thesis focuses on introduce problematic issue of inter-core communication, implementation of Linux distribution made by project Yocto on chosen platform of NXP i.MX microcontrolers family and solution for secured inter-core communication.
49

Impacts of Changing the Transit Signal Priority Requesting Threshold on Bus Performance and General Traffic: A Sensitivity Analysis

Sheffield, Michael Harmon 17 June 2020 (has links)
A sensitivity analysis was performed on the transit signal priority (TSP) requesting threshold to evaluate its impact on bus performance and general traffic. Two distinct bus routes were evaluated to determine the optimal requesting threshold that would balance the positive impacts on bus performance with the negative impacts on general traffic. Route 217, a conventional bus route, and the Utah Valley Express (UVX), a bus rapid transit line, utilize a dedicated short-range communication (DSRC)-based TSP system as part of their normal, day-to-day operations. Using field-generated data exclusively, bus performance and general traffic were evaluated over a 7-month period from February through August 2019. Bus performance was evaluated through on-time performance (OTP), schedule deviation, travel time, and dwell time, while the traffic analysis was performed by evaluating split failure, change in green time, and the frequency at which TSP was served. The requesting thresholds evaluated for Route 217 were 5-, 3-, 2-, and 0-minutes, which stipulate how far behind schedule the bus must be in order to request TSP. For UVX, 5-minutes and 2-minutes, as well as ON and OFF scenarios were evaluated; ON meant the buses were always requesting regardless of how late they were, while OFF meant that no requests were made and operations would be as if there were no TSP at all. A combination of observational and statistical analyses concluded with convincing evidence that OTP, schedule deviation, and travel time improve as the requesting threshold approaches zero with negligible impacts to general traffic. For Route 217, as the requesting threshold changed from 3, to 2, to 0 minutes, OTP increased 2.0 and 2.5 percent, respectively, mean schedule deviation improved 15.9 and 20.9 seconds, respectively, and travel time decreased at 72 percent of timepoints. Meanwhile, negative impacts to traffic occurred if an increase in split failure was measured after TSP was served, a phenomenon observed a maximum of once every 43 minutes. For UVX, as the requesting threshold changed from 5, to 2 minutes, to ON, OTP increased 7.6 and 4.7 percent, respectively, mean schedule deviation improved 24.3 and 15.0 seconds, respectively, and travel time decreased between 72 percent of timepoints. Thus, it is concluded that under the TSP system as implemented, bus performance improves as the requesting threshold approaches zero with inconsequential impacts to general traffic.
50

Operating System Based Perceptual Evaluation of Call Quality in Radio Telecommunications Networks. Development of call quality assessment at mobile terminals using the Symbian operating system, comparison with traditional approaches and proposals for a tariff regime relating call charging to perceived speech quality.

Aburas, Akram January 2012 (has links)
Call quality has been crucial from the inception of telecommunication networks. Operators need to monitor call quality from the end-user¿s perspective, in order to retain subscribers and reduce subscriber ¿churn¿. Operators worry not only about call quality and interconnect revenue loss, but also about network connectivity issues in areas where mobile network gateways are prevalent. Bandwidth quality as experienced by the end-user is equally important in helping operators to reduce churn. The parameters that network operators use to improve call quality are mainly from the end-user¿s perspective. These parameters are usually ASR (answer seizure ratio), PDD (postdial delay), NER (network efficiency ratio), the number of calls for which these parameters have been analyzed and successful calls. Operators use these parameters to evaluate and optimize the network to meet their quality requirements. Analysis of speech quality is a major arena for research. Traditionally, users¿ perception of speech quality has been measured offline using subjective listening tests. Such tests are, however, slow, tedious and costly. An alternative method is therefore needed; one that can be automatically computed on the subscriber¿s handset, be available to the operator as well as to subscribers and, at the same time, provide results that are comparable with conventional subjective scores. QMeter® ¿ a set of tools for signal and bandwidth measurement that have been developed bearing in mind all the parameters that influence call and bandwidth quality experienced by the end-user ¿ addresses these issues and, additionally, facilitates dynamic tariff propositions which enhance the credibility of the operator. This research focuses on call quality parameters from the end-user¿s perspective. The call parameters used in the research are signal strength, successful call rate, normal drop call rate, and hand-over drop rate. Signal strength is measured for every five milliseconds of an active call and average signal strength is calculated for each successful call. The successful call rate, normal drop rate and hand-over drop rate are used to achieve a measurement of the overall call quality. Call quality with respect to bundles of 10 calls is proposed. An attempt is made to visualize these parameters for better understanding of where the quality is bad, good and excellent. This will help operators, as well as user groups, to measure quality and coverage. Operators boast about their bandwidth but in reality, to know the locations where speed has to be improved, they need a tool that can effectively measure speed from the end-user¿s perspective. BM (bandwidth meter), a tool developed as a part of this research, measures the average speed of data sessions and stores the information for analysis at different locations. To address issues of quality in the subscriber segment, this research proposes the varying of tariffs based on call and bandwidth quality. Call charging based on call quality as perceived by the end-user is proposed, both to satisfy subscribers and help operators to improve customer satisfaction and increase average revenue per user. Tariff redemption procedures are put forward for bundles of 10 calls and 10 data sessions. In addition to the varying of tariffs, quality escalation processes are proposed. Deploying such tools on selected or random samples of users will result in substantial improvement in user loyalty which, in turn, will bring operational and economic advantages.

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