CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O projeto aerodinÃmico de um rotor eÃlico visa a otimizaÃÃo dos parÃmetros de funcionamento, para que este forneÃa uma maior eficiÃncia no regime de operaÃÃo em que à utilizado. O presente trabalho consiste na criaÃÃo de um software em linguagem C++, por meio do ambiente de desenvolvimento integrado C++Builder, atravÃs de um mÃtodo clÃssico de projeto de turbinas eÃlicas baseado na Teoria do Momento do Elemento de Pà (BEM). O software fornece ao usuÃrio dados geomÃtricos de construÃÃo, como curvas de afilamento e torÃÃo da pà com base nos dados dos aerofÃlios utilizados. A anÃlise da curva de potÃncia à feita e mostrada atravÃs de um grÃfico caracterÃstico. O software prediz as alteraÃÃes de desempenho devido Ãs perdas pela ponta e pela raiz da pÃ, e tambÃm informa, entre outras coisas, a distribuiÃÃo das cargas mÃximas ao longo da mesma, de acordo com a faixa de operaÃÃo desejada pelo usuÃrio. A potÃncia fornecida pelo aerogerador pode ser calculada atravÃs de dados de velocidade dos ventos. / The aerodynamic design of a wind rotor aims to optimize the operating parameters, so that this provides a more efficient system operation in which it is used. This work consists in creating a software in C + + language through the integrated development environment C + + Builder, via a classic method of wind turbines design based on the Blade Element Momentum Theory (BEM). The software provides the user with geometric data for building, such as curved taper of the blade and torsion based on the airfoils data used. The power curve analysis is performed and displayed via a characteristic plot. The software predicts performance changes due to losses by the tip and the root of the blade, and also shows, among other things, the distribution of maximum loads along the blade, in the operating range desired by the user. The power delivered by the turbine can be calculated using wind speed data.

Orientador: Marco Aurelio Amaral Henriques / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T23:04:47Z (GMT). No. of bitstreams: 1 Herai_RobertoHirochi_M.pdf: 4053882 bytes, checksum: c48bdb80fdf9c0bbdb2249a62b3a2345 (MD5) Previous issue date: 2005 / Resumo: A predição de desempenho é um importante mecanismo para avaliar a utilização de recursos e estimar o tempo de execução de aplicações em sistemas paralelos. Este trabalho apresenta uma ferramenta que permite criar modelos que representam características da aplicação e dos computadores utilizados para processá-la. Tais modelos são combinados para gerar um modelo de desempenho mais abrangente, cuja análise permite obter estimativas de tempo de execução que contemplem fatores de atraso tais como operações aritméticas sobre diferentes tipos de dados e efeitos de contenção, causados por concorrência. As estimativas podem ser geradas em poucos segundos e permitem analisar o impacto causado na aplicação pela utilização de diferentes configurações do sistema de processamento paralelo. A ferramenta foi implementada para um sistema de processamento paralelo baseado em Java, chamado JoiN, e ela mostrou ser possível obter estimativas satisfatórias de tempos de execução para diversos tipos de aplicações paralelas / Abstract: Performance prediction is an important mechanism to evaluate the use of resources and predict the execution time of applications in parallel systems. This work presents a tool for the creation of models that represent applications and computers characteristics. Such models are combined to generate a performance model, whose analysis derives execution time estimates that include delay factors, such as arithmetic operations on different data types and contention effects caused by process concurrence. The estimates can be generated in a few seconds and allow the analysis of the impact caused in the application by changes in the parallel system configuration. The tool was implemented for a Java based parallel processing system called JoiN and it showed that satisfactory execution time estimates can be obtained for several types of parallel applications / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

The thesis presents a survey of techniques for accurate prediction of traffic distribution in computer network systems.

Performance objectives are often neglected during the design phase of a project, and performance problems are often not discovered until the system is implemented. Therefore, there is a need from the industry to find a method to predict the performance of a system early in the design phase. One method that tries to solve this problem is the Software Performance Engineering (SPE) method. This report gives a short introduction to software performance and an overview of the SPE method for performance prediction. It also contains a case study where SPE is applied on an existing system.

Abstract This thesis seeks to develop a robust semi-analytical performance prediction method for an advanced iterative receiver that processes spatially multiplexed signals that have propagated through frequency-selective receive correlated multiple-input multiple-output (MIMO) wireless communication channels. In a change of perspective, the proposed performance prediction methods are applied at the transmitter, which seeks to attain a target frame error rate (FER) either by adaptive power control or by adaptive modulation and coding (AMC). The performance prediction scheme utilises the statistical properties of the channel—namely noise variance, number of separable propagation paths and the eigenvalues of the receive correlation matrix—to predict the signal-to-interference-plus-noise ratio (SINR) at the output of a frequency domain soft interference cancellation minimum mean square error equaliser. The SINR distribution is used to derive the distribution of the variance of the log-likelihood ratios (LLRs) at the output of a soft symbol-to-bit demapper. Mutual information transfer charts establish a bijective relationship between the variance of the LLRs and mutual information. A 3rd Generation Partnership Project compliant turbo code is assumed. Since the decoder operates independently from the channel, its extrinsic information transfer (EXIT) charts can be simulated in advance. By utilising the approximate LLR variance distribution of the demapped equaliser output, it is possible to evaluate the probability of an intersection between an equaliser chart associated with a random channel realisation and a fixed decoder chart. This probability provides the FER. Since the proposed performance prediction method does not require any instantaneous channel state information, it can be applied at the transmitter side as a robust link adaptation scheme. In adaptive transmission power control, the modulation order and code rate are fixed. By iteratively adjusting transmission power, the transmitter attempts to find an equaliser output LLR variance distribution that reaches a specified target FER. In AMC, transmission power is fixed. The equaliser output's LLR variance distribution is determined by the modulation order, while the decoder chart's position is determined by the code rate. The transmitter iteratively adjusts the code rate and attempts to find a modulation order and code rate pairing that reaches the target FER. For vertically encoded spatially multiplexed systems, the adaptive transmission power control and AMC schemes are complemented by adaptive repeat redundancy and incremental redundancy hybrid automatic repeat request (HARQ) techniques, respectively. / Tiivistelmä Työn tavoitteena on kehittää luotettava semianalyyttinen suorituskyvyn ennustusmenetelmä tehokkaalle iteratiiviselle vastaanottimelle, joka käsittelee taajuusselektiivisen, vastaanotinpäässä tilakorreloituneen moniantennikanavan kautta kulkeneita tilakanavoituja signaaleja. Toisessa vaiheessa esitettyjä ennustusmenetelmiä hyödynnetään mukauttamalla lähetystehoa tai modulaatioastetta ja koodisuhdetta (adaptive modulation and coding [AMC]), samalla säilyttäen tavoitteeksi asetetun kehysvirhesuhteen (frame error rate [FER]). Suorituskyvyn ennustusmenetelmä hyödyntää kanavan tilastollisia ominaisuuksia – kohinan varianssia, eroteltavien etenemispolkujen lukumäärää sekä vastaanottimen korrelaatiomatriisin ominaisarvoja – ennustaakseen signaali–kohina-plus-interferenssisuhteen (signal-to-interference-plus-noise ratio [SINR]) jakauman taajuustasossa toimivan, häiriötä poistavan pienimmän keskineliösumman kanavakorjaimen lähdössä. SINR-jakaumasta johdetaan pehmän symboleista biteiksi -muunnoksen jälkeisten logaritmisten bittitodennäköisyyksien suhdelukujen (log-likelihood ratio [LLR]) jakauma. Keskinäisinformaation siirroskartat perustuvat LLR:ien varianssin sekä keskinäisinformaation väliseen bijektiivisyyteen. Informaatio on kanavakoodattu 3rd Generation Partnership Project -standardin mukaisella turbokoodilla. Turbodekooderin toiminta on kanavasta riippumatonta, joten dekooderin lisäinformaation siirroskartat (extrinsic information transfer [EXIT] charts) voidaan simuloida itsenäisesti. Hyödyntämällä kanavakorjaimen lähdön pehmeiden bittipäätösten LLR:ien varianssin jakaumaa, on mahdollista arvioida millä todennäköisyydellä korjaimen satunnaisen kanavarealisaation siirroskartta leikkaa dekooderin siirroskartan. Tämä todennäköisyys voidaan tulkita kehysvirhesuhteeksi. Koska suorituskyvyn ennustusmenetelmä ei vaadi hetkellistä tietoa kanavan tilasta, sitä voidaan hyödyntää lähetyksen mukautuksessa. Mukautuvassa tehonsäädössä modulaatio ja koodisuhde eivät muutu. Lähetin pyrkii iteratiivisella tehonsäädöllä löytämään korjaimen lähdölle LLR-jakauman, joka tuottaa halutun kehysvirhesuhteen. Mukautuvassa modulaation ja koodisuhteen valinnassa lähetysteho säilyy vakiona. Modulaatioaste vaikuttaa korjaimen lähdön LLR-jakaumaan ja koodisuhde dekooderin siirroskartan muotoon. Iteratiivisesti koodisuhdetta säätämällä lähetin pyrkii löytämään modulaation ja koodisuhteen yhdistelmän, joka saavuttaa tavoitellun kehysvirhesuhteen. Vertikaalisesti tilakanavoiduissa järjestelmissä mukautuvaa tehonsäätöä täydennetään lähetystehoa mukauttavilla uudellenlähetyksillä, kun taas mukautuvaa modulaation ja koodisuhteen valintaa täydennetään puolestaan koodisuhdetta pienentävillä automattisilla uudelleenlähetyspyynnöillä (hybrid automatic repeat request [HARQ]).

Dans le contexte de la vision par ordinateur, le choix d’une architecture de calcul est devenu de plus en plus complexe pour un spécialiste du traitement d’images. Le nombre d’architectures permettant de résoudre des algorithmes de traitement d’images augmente d’année en année. Ces algorithmes s’intègrent dans des cadres eux-mêmes de plus en plus complexes répondant à de multiples contraintes, que ce soit en terme de capacité de calculs, mais aussi en terme de consommation ou d’encombrement. A ces contraintes s’ajoute le nombre grandissant de types d’architectures de calculs pouvant répondre aux besoins d’une application (CPU, GPU, FPGA). L’enjeu principal de l’étude est la prédiction de la performance d’un système, cette prédiction pouvant être réalisée en phase amont d’un projet de développement dans le domaine de la vision. Dans un cadre de développement, industriel ou de recherche, l’impact en termes de réduction des coûts de développement, est d’autant plus important que le choix de l’architecture de calcul est réalisé tôt. De nombreux outils et méthodes d’évaluation de la performance ont été développés mais ceux-ci, se concentrent rarement sur un domaine précis et ne permettent pas d’évaluer la performance sans une étude complète du code ou sans la réalisation de tests sur l’architecture étudiée. Notre but étant de s’affranchir totalement de benchmark, nous nous sommes concentrés sur le domaine du traitement d’images pour pouvoir décomposer les algorithmes du domaine en éléments simples ici nommées briques élémentaires. Dans cette optique, un nouveau paradigme qui repose sur une décomposition de tout algorithme de traitement d’images en ces briques élémentaires a été conçu. Une méthode est proposée pour modéliser ces briques en fonction de paramètres software et hardwares. L’étude démontre que la décomposition en briques élémentaires est réalisable et que ces briques élémentaires peuvent être modélisées. Les premiers tests sur différentes architectures avec des données réelles et des algorithmes comme la convolution et les ondelettes ont permis de valider l'approche. Ce paradigme est un premier pas vers la réalisation d’un outil qui permettra de proposer des architectures pour le traitement d’images et d’aider à l’optimisation d’un programme dans ce domaine. / In computer vision, the choice of a computing architecture is becoming more difficult for image processing experts. Indeed, the number of architectures allowing the computation of image processing algorithms is increasing. Moreover, the number of computer vision applications constrained by computing capacity, power consumption and size is increasing. Furthermore, selecting an hardware architecture, as CPU, GPU or FPGA is also an important issue when considering computer vision applications.The main goal of this study is to predict the system performance in the beginning of a computer vision project. Indeed, for a manufacturer or even a researcher, selecting the computing architecture should be done as soon as possible to minimize the impact on development.A large variety of methods and tools has been developed to predict the performance of computing systems. However, they do not cover a specific area and they cannot predict the performance without analyzing the code or making some benchmarks on architectures. In this works, we specially focus on the prediction of the performance of computer vision algorithms without the need for benchmarking. This allows splitting the image processing algorithms in primitive blocks.In this context, a new paradigm based on splitting every image processing algorithms in primitive blocks has been developed. Furthermore, we propose a method to model the primitive blocks according to the software and hardware parameters. The decomposition in primitive blocks and their modeling was demonstrated to be possible. Herein, the performed experiences, on different architectures, with real data, using algorithms as convolution and wavelets validated the proposed paradigm. This approach is a first step towards the development of a tool allowing to help choosing hardware architecture and optimizing image processing algorithms.

The computational Grid has become an important infrastructure as an execution environment for scientific applications that require large amount of computing resources. Applications which would otherwise be unmanageable or take a prohibitively longer execution time under previous computing paradigms can now be executed efficiently on the Grid within a reasonable time. Multi-agent based simulation (MABS) is a methodology used to study and understand the dynamics of real world phenomena in domains involving interaction and/or cooperative problem solving where the participants are characterized by entities having autonomous and social behaviour. For certain domains the size of the simulation is extremely large, intractable without employing adequate computing resources such as the Grid. Although the Grid has come with immense opportunities to resource demanding applications such as MABS, it has also brought with it a number of challenges related to performance. Performance problems may have their origins either on the side of the computing infrastructure or the application itself, or both. This thesis aims at improving the performance of MABS applications by overcoming problems inherent to the behaviour of MABS applications. It also studies the extent to which the MABS technologies have been exploited in the field of simulation and find ways to adapt existing technologies for the Grid. It investigates performance monitoring and prediction systems in the Grid environment and their implementation for MABS application with the purpose of identifying application related performance problems and their solutions. Our research shows that large-scale MABS applications have not been implemented despite the fact that many problem domains that cannot be studied properly with only partial simulation. We assume that this is due to the lack of appropriate tools such as MABS platforms for the Grid. Another important finding of this work is the improvement of application performance through the use of MABS specific middleware.

No description available.

Projecting performance of applications and hardware is important to several market segments—hardware designers, software developers, supercomputing centers, and end users. Hardware designers estimate performance of current applications on future systems when designing new hardware. Software developers make performance estimates to evaluate performance of their code on different architectures and input datasets. Supercomputing centers try to optimize the process of matching computing resources to computing needs. End users requesting time on supercomputers must provide estimates of their application’s run time, and incorrect estimates can lead to wasted supercomputing resources and time. However, application performance is challenging to predict because it is affected by several factors in application code, specifications of system hardware, choice of compilers, compiler flags, and libraries. This dissertation uses statistical techniques to model and optimize performance of scientific applications across different computer processors. The first study in this research offers statistical models that predict performance of an application across different input datasets prior to application execution. These models guide end users to select parameters that produce optimal application performance during execution. The second study offers a suite of statistical models that predict performance of a new application on a new processor. Both studies present statistical techniques that can be generalized to analyze, optimize, and predict performance of diverse computation- and data-intensive applications on different hardware.

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第19855号 / 情博第606号 / 新制||情||105(附属図書館) / 32891 / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 石田 亨, 教授 吉川 正俊, 教授 岡部 寿男 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM