Cache memory is used, in most single-core and multi-core processors, to improve performance by bridging the speed gap between the main memory and CPU. Even though cache increases performance, it poses some serious challenges for embedded systems running real-time applications. Cache introduces execution time unpredictability due to its adaptive and dynamic nature and cache consumes vast amount of power to be operated. Energy requirement and execution time predictability are crucial for the success of real-time embedded systems. Various cache optimization schemes have been proposed to address the performance, power consumption, and predictability issues. However, currently available solutions are not adequate for real-time embedded systems as they do not address the performance, power consumption, and execution time predictability issues at the same time. Moreover, existing solutions are not suitable for dealing with multi-core architecture issues. In this dissertation, we develop a methodology through cache optimization for real-time embedded systems that can be used to analyze and improve execution time predictability and performance/power ratio at the same time. This methodology is effective for both single-core and multi-core systems. First, we develop a cache modeling and optimization technique for single-core systems to improve performance. Then, we develop a cache modeling and optimization technique for multi-core systems to improve performance/power ratio. We develop a cache locking scheme to improve execution time predictability for real-time systems. We introduce Miss Table (MT) based cache locking scheme with victim cache (VC) to improve predictability and performance/power ratio. MT holds information about memory blocks, which may cause more misses if not locked, to improve cache locking performance. / VC temporarily stores the victim blocks from level-1 cache to improve cache hits. In addition, MT is used to improve cache replacement performance and VC is used to improve cache hits by supporting stream buffering. We also develop strategies to generate realistic workload by characterizing applications to simulate cache optimization and cache locking schemes. Popular MPEG4, H.264/AVC, FFT, MI, and DFT applications are used to run the simulation programs. Simulation results show that newly introduced Miss Table based cache locking scheme with victim cache significantly improves the predictability and performance/power ratio. In this work, a reduction of 33% in mean delay per task and a reduction of 41% in total power consumption are achieved by using MT and VCs while locking 25% of level-2 cache size in an 4-core system. It is also observed that execution time predictability can be improved by avoiding more than 50% cache misses while locking one-fourth of the cache size. / by Abu Asaduzzaman. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Recent years have witnessed the emergence of microprocessors that are embedded within a plethora of devices used in everyday life. Embedded architectures are customized through a meticulous and time consuming design process to satisfy stringent constraints with respect to performance, area, power, and cost. In embedded systems, the cost of the memory hierarchy limits its ability to play as central a role. This is due to stringent constraints that fundamentally limit the physical size and complexity of the memory system. Ultimately, application developers and system engineers are charged with the heavy burden of reducing the memory requirements of an application. This thesis offers the intriguing possibility that compilers can play a significant role in the automatic design space exploration and optimization of embedded memory systems. This insight is founded upon a new analytical model and novel compiler optimizations that are specifically designed to increase the synergy between the processor and the memory system. The analytical models serve to characterize intrinsic program properties, quantify the impact of compiler optimizations on the memory systems, and provide deep insight into the trade-offs that affect memory system design.

Made available in DSpace on 2015-12-03T18:32:52Z (GMT). No. of bitstreams: 1 Hilda_Marina_da_Rocha_Rinaldi.pdf: 285748 bytes, checksum: 3b5e3ebb023bf361d5eb9a130462d343 (MD5) Previous issue date: 2003-10-10 / The purpose of this research was to obtain an adequate hiring process for the systems development outsourcing, to obtain a fair precification for the job, through a more precise quantification of the necessary efforts involved, aiming to avoid constant pricing reviews coming from changes in the efforts forecasted at thebeginning. The research's key point was the building of an instrument allowing the perfect identification of most expressive issues to be outlined in a request for system development, then making contracts handling a routine in accordance with international standards. After reviewing many of the existing software metrics, the research led to the adequacy of the FPA (Function Point Analysis) in the contractors / users relationship handling, considering that it is internationally accepted for being an ISO regulation and it is in accordance with the requirements of another ISO regulation, regarding to Functional Size Measurement. One of the research's achievements was that the FPA use allows a better evaluation of the bids offered by suppliers, favoring an hiring with fair price and avoiding contract reviews that very often led to undesirable price reviews. Concerning to the methodology, 3 pre-tests were prepared using a small and selected sample constituted by professionals, in both developing systems and outsourcing areas. These professionals were skilled in metrics. Based on the pre-test results, a questionnaire was prepared, containing 16 questions to be answered by a group of professionals, with skills very alike of those in the pre-test answerers. Answers were given through marking one out of five alternatives according to Likert Scale. The resulting data were evaluated using the SPSS software, base 10.0 and analyzing 16 answers frequency. Both Factorial and Discriminant Analysis were used. To make the research more relevant, other statistical data were analyzed to verify the answerer's conditions, if contractor or user, and the impact of the time working in the system area and the job position in the answers. As result of the research, relevant issues to be considered in an outsourcing contract could be observed, being the main one the existence of a metric to enhance transparency and objectivity involving contractors/users relationship and leading to the most adequate price. / O prop??sito desta pesquisa foi obter um processo adequado de terceiriza????o de contrata????o de desenvolvimento de sistemas, para resultar numa precifica????o mais justa do trabalho por meio de uma quantifica????o do esfor??o necess??rio envolvido, visando evitar revis??es constantes dos pre??os advindos de mudan??as no esfor??o previsto no in??cio do trabalho. O ponto focal da pesquisa foi a constru????o de um instrumento que possibilitasse identificar perfeitamente os mais significativos assuntos numa requisi????o de desenvolvimento de sistemas, tornando a gest??o de contratos uma rotina amparada em padr??es internacionais. Ap??s a an??lise de v??rias t??cnicas de medi????o de software existentes, a pesquisa concluiu que a An??lise de Pontos de Fun????o demonstrou ser a mais indicada para a gest??o das rela????es entre CONTRATANTES e CONTRATADAS, por se tratar de uma t??cnica aceita internacionalmente, ser uma norma ISO e estar em conformidade com outra norma ISO que considera o projeto para Medi????o Funcional de Software. Uma das resultantes da pesquisa foi que o uso da An??lise de Pontos de Fun????o possibilita uma melhor avalia????o das propostas apresentadas pelos fornecedores, favorecendo uma contrata????o por um pre??o mais equilibrado evitando revis??es de contratos que freq??entemente levam ?? indesej??veis revis??es de pre??os. De acordo com a metodologia foram realizados 3 pr??-testes com uma amostra selecionada constitu??da de profissionais atuantes em desenvolvimento de sistemas e em terceiriza????o e tamb??m com conhecimento de m??tricas de software. Baseado nos resultados do pr??-teste foi elaborado um instrumento com 16 assertivas para serem respondidas por um grupo de profissionais com habilidades bastante parecidas com as dos respondentes do pr??-teste. As respostas deveriam ser assinaladas por meio da escolha de uma entre cinco alternativas de acordo com a escala de Likert. Os dados resultantes foram analisados com apoio do software SPSS base 10.0 e verificadas as freq????ncias das 16 respostas. Tamb??m foram utilizados os m??todos de an??lise fatorial e de an??lise discriminante. Para tornar a pesquisa mais relevante, outros dados estat??sticos foram analisados para que se verificasse se as respostas aderiam ??s condi????es dos respondentes como CONTRATADA ou como CONTRATANTE e o impacto do tempo de experi??ncia na ??rea e o tipo de fun????o exercida. Como resultado da pesquisa foi observado que considera????es relevantes devem ser levadas em conta em um contrato de desenvolvimento de sistemas, sendo a principal delas a exist??ncia de uma m??trica, para que se tenha mais transpar??ncia e objetividade entre CONTRATANTE e CONTRATADA e que se pratique o pre??o mais adequado.

Plenty of novel emerging technologies are being proposed and evaluated today, mostly at the device and circuit levels. It is unclear what the impact of different new technologies at the system level will be. What is clear, however, is that new technologies will make their way into systems and will increase the already high complexity of heterogeneous parallel computing platforms, making it ever so difficult to program them. This paper discusses a programming stack for heterogeneous systems that combines and adapts well-understood principles from different areas, including capability-based operating systems, adaptive application runtimes, dataflow programming models, and model checking. We argue why we think that these principles built into the stack and the interfaces among the layers will also be applicable to future systems that integrate heterogeneous technologies. The programming stack is evaluated on a tiled heterogeneous multicore.

The purpose of this project is to investigate the differences between psychoacoustic principles and genetic algorithms (GA0). These will be discussed separately. The review will also compare the compression ratio and the quality of the decompressed files decoded by these two methods.

Indiana University-Purdue University Indianapolis (IUPUI) / With the advances in embedded technology and the omnipresence of smartphones, tracking systems do not need to be confined to a specific tracking environment. By introducing mobile devices into a tracking system, we can leverage their mobility and the availability of multiple sensors such as camera, Wi-Fi, Bluetooth and Inertial sensors. This thesis proposes to improve the existing tracking systems, enhanced Distributed Tracking System (e-DTS 2.0) [19] and enhanced Distributed Object Tracking System (eDOTS)[26], in the form of e-DTS 3.0 and provides an empirical analysis of these improvements. The enhancements proposed are to introduce Android-based mobile devices into the tracking system, to use multiple sensors on the mobile devices such as the camera, the Wi-Fi and Bluetooth sensors and inertial sensors and to utilize possible resources that may be available in the environment to make the tracking opportunistic. This thesis empirically validates the proposed enhancements through the experiments carried out on a prototype of e-DTS 3.0.