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Parameter study of bodywork attachments influencing the chassis dynamics by vibration response analysis / Parameterstudie av fästelements betydelse för chassidynamikenDeshpande, Anirudh Gururaj January 2018 (has links)
Bilindustrin är i ständig utveckling och är väl medvetna om de ökande kraven från kundermed avseende på körkomfort och körupplevelse. Lastbilar med tunga laster är ofta utrustademed en påbyggnad, till exempel en låda för pallar och gods, en sopsamlare eller en stödram förbärning av timmer. SCANIA Bodybuilding Center utvecklar riktlinjer för val av olika typer avkarosseri, dvs typ av stödram och antal , fästpunkter. Målet med detta arbete är att utvecklaen bättre förståelse för hur det stödjande ramverket och dess infästningar i en lastbil påverkarrammens dynamik och sedan föreslå förbättringar till dessa riktlinjer.Viktiga parametrar som påverkar chassisdynamiken identifierades och beskrivs från början.Fysisk vibrationstestning av chassiet och påbyggnadsram med fasthållningsfäste utfördes vidi testrigg på Scania R&D. Frekvensresponsfunktionerna från mätningarna användes för attbestämma modala parametrar. Olika test utfördes genom att ändra parametrarna och upptagningenav mätningarna. Testresultaten användes för att studera egenfrekvenser egna frekvenser,modifieringsformer och dämpning i systemet. Även en ny metod för att bygga en dynamiskfinit element (FE) modell eller chassi och påbyggnadsram är presenterad i denna undersökning.Modalanalys av chassi-påbygnadsramssystemet gjordes för att studera FEMs egna frekvenseroch modeformer. Den föreslagna metoden för koppling av chassit och delramen i FEM är kritisktbedömd genom att korrelera FE-simuleringen med de experimentella resultaten. Baserat på deutförda experimenten och den numeriska simuleringen föreslås från experiment och numerisksimulering, föreslås nya rekommendationer med avseende på påbyggnadsanslutningarnas konfigurationi lastbil. / The automotive sector is continuously evolving and the companies are well aware of therising demands from customers with regard to driving comfort and experience. Trucks carryingheavy loads are often equipped with on-built bodywork, for example a box for pallets and goods, agarbage collector device or a supporting frame for carrying timber. SCANIA bodybuilding centredevelops guidelines for selecting different types of bodywork, i.e. the type of supporting frame,design and number of attachment brackets, attachment points. The purpose of this master thesisis to develop a better understanding of how the supporting frame and its attachments in a truckinfluence the chassis frame dynamics and to propose improvements to these guidelines.Major parameters influencing the chassis dynamics were identified and described from theoutset. Physical vibration testing of the chassis-subframe assembly was carried out at roadsimulator. The frequency response functions from the measurements were used to determinethe modal parameters. Several tests were performed by altering the parameters and recordingthe measurements. The results from the test cases were used to study and analyse the eigenfrequencies, mode shapes and damping in the system. Also, a new method to build a dynamicfinite element (FE) model of chassis and subframe is presented in this study. Modal analysisof the chassis-subframe assembly was done to study the eigen frequencies and mode shapes byFEM. The proposed method of coupling the chassis and the subframe is critically assessed bycorrelating the results from FE simulation with the experimental results. Based on the resultsfrom experiment and numerical simulation, new recommendations are proposed with regard tothe bodywork attachments’ configuration in the truck.
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Enhanced energy detection based spectrum sensing in cognitive radio networks using Random Matrix TheoryAhmed, A., Hu, Yim Fun, Noras, James M. January 2014 (has links)
No / Opportunistic secondary usage of underutilised radio spectrum is currently of great interest and the use of TV White Spaces (TVWS) has been considered for Long Term Evolution (LTE) broadband services. However, wireless microphones operating in TV bands pose a challenge to TVWS opportunistic access. Efficient and proactive spectrum sensing could prevent harmful interference between collocated devices, but existing spectrum sensing schemes such as energy detection and schemes based on Random Matrix Theory (RMT) have performance limitations. We propose a new blind spectrum sensing scheme with higher performance based on RMT supported by a new formula for the estimation of noise variance. The performance of the proposed scheme has been evaluated through extensive simulations on wireless microphone signals. The proposed scheme has also been compared to energy detection schemes, and shows higher performance in terms of the probability of false alarm (Pfa) and probability of detection (Pd).
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A Generic Approach to Network Modeling for Harmonic AnalysisMaitra, Arindam 11 May 2002 (has links)
Beginning the study with a regional network map with an intent to perform a detailed harmonic study for a certain location, the first question that comes up is how far out in the system should detailed modeling of individual devices (transmission lines, loads, transformers, capacitor banks, etc) be done. The reason why this is extremely important is because system components that will affect the frequency response characteristics in the specific location should not be missed or poorly modeled. Frequency scan is the simplest and most commonly used simulation technique used to characterize the response of a power system network as a function of frequency. Unfortunately, there are two major problems using frequency scan techniques when real harmonic studies are considered: 1) the size of the admittance matrices (this calculation is repeated using discrete frequency steps throughout the range of interest) may be so large that an exact mathematical model of the system is not realistic and 2) the complexity of a rigorous and complete mathematical model of the system does not necessarily explain the extent to which system components affect the frequency response characteristics in a specified location. It is seldom clear how much of the system must be represented in order to get accurate results in a harmonic study. Realistic procedures to identify whether to include a particular element in a detailed model or to lump the element into a simplifying equivalent are yet to be developed in the industry. It is safe to say that practicing engineers are using tools and techniques of questionable validity. Two new computer-oriented methods that use eigen analysis techniques to identify easily and accurately the boundary between system areas to be modeled in detail and those represented by equivalents are proposed in this dissertation. The key here is to recognize that not all elements present in the ?external? system will participate in the resonant harmonic modes and could therefore be lumped into a simplified short-circuit equivalent. Achieving these objectives from either one of the two methods can be economically attractive. In short, the work described in this dissertation is a fundamentally sound alternative for the purposes of network equivalencing and model reduction.
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Random matrix theory based spectrum sensing for cognitive radio networksAhmed, A., Hu, Yim Fun, Noras, James M., Pillai, Prashant, Abd-Alhameed, Raed, Smith, A. 05 November 2015 (has links)
No / Dynamic Spectrum Access (DSA) for secondary usage of underutilized radio spectrum is currently of great interest for radio regulatory authorities and for cellular network operators. However, the co-existence of multiple devices operating in the same bands, such as wireless microphones which also operate in TV bands, poses a challenge to DSA. Efficient and proactive spectrum sensing could prevent harmful interference between collocated devices, but existing blind spectrum sensing schemes such as energy detection and schemes based on Random Matrix Theory (RMT) have performance limitations. We propose a new blind spectrum sensing scheme for cognitive radio. The proposed scheme uses a new formula for the estimation of noise variance. The scheme has been evaluated through extensive simulations on wireless microphone signals and shows higher performance as compared to energy detection and RMT-based sensing schemes such as MME and EME. It also shows higher performance in terms of probability of detection (Pd).
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Parametric covariance assignment using a reduced-order closed-form covariance modelZhang, Qichun, Wang, Z., Wang, H. 03 October 2019 (has links)
Yes / This paper presents a novel closed-form covariance model using covariance matrix decomposition for both continuous-time and discrete-time stochastic systems which are subjected to Gaussian noises. Different from the existing covariance models, it has been shown that the order of the presented model can be reduced to the order of original systems and the parameters of the model can be obtained by Kronecker product and Hadamard product which imply a uniform expression. Furthermore, the associated controller design can be simplified due to the use of the reduced-order structure of the model. Based on this model, the state and output covariance assignment algorithms have been developed with parametric state and output feedback, where the computational complexity is reduced and the extended free parameters of parametric feedback supply flexibility to the optimization. As an extension, the reduced-order closed-form covariance model for stochastic systems with parameter uncertainties is also presented in this paper. A simulated example is included to show the effectiveness of the proposed control algorithm, where encouraging results have been obtained. / National Natural Science Foundation of China [grant number 61573022], [grant number 61290323] and [grant number 61333007]
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Mécanismes de transfert de proton d’une réaction acido-basique en phase aqueuse : une étude ab-initioRivard, Ugo 11 1900 (has links)
Les réactions de transfert de proton se retrouvent abondamment dans la nature et sont des processus cruciaux dans plusieurs réactions chimiques et biologiques, qui se produisent souvent en milieu aqueux. Les mécanismes régissant ces échanges de protons sont complexes et encore mal compris, suscitant un intérêt des chercheurs en vue d’une meilleure compréhension fondamentale du processus de transfert. Le présent manuscrit présente une étude mécanistique portant sur une réaction de transfert de proton entre un acide (phénol fonctionnalisé) et une base (ion carboxylate) en phase aqueuse. Les résultats obtenus sont basés sur un grand nombre de simulations de dynamique moléculaire ab-initio réalisées pour des systèmes de type « donneur-pont-accepteur », où le pont se trouve à être une unique molécule d’eau, permettant ainsi l’élaboration d’un modèle cinétique détaillé pour le système étudié. La voie de transfert principalement observée est un processus ultra-rapide (moins d’une picoseconde) passant par la formation d’une structure de type « Eigen » (H9O4+) pour la molécule d’eau pontante, menant directement à la formation des produits. Une seconde structure de la molécule d’eau pontante est également observée, soit une configuration de type « Zündel » (H5O2+) impliquant l’accepteur de proton (l’ion carboxylate) qui semble agir comme un cul-de-sac pour la réaction de transfert de proton. / Proton transfer reactions are found abundantly in nature and are critical processes in several chemical and biological reactions, which often occur in aqueous medium. The mechanisms governing these proton exchanges are complex and poorly understood, sparking interest of researchers for a better fundamental understanding of the transfer process. This manuscript presents a mechanistic study for a proton transfer reaction between an acid (functionalized phenol) and a base (carboxylate ion) in aqueous phase. The results are based on a large number of Ab-initio molecular dynamics simulations performed for a “donor-bridge-acceptor” type of system, where the bridge is a single molecule of water, allowing the development of a detailed kinetic model for this system. The transfer channel mainly observed is an ultra-fast one (less than a picosecond), through the formation of a Eigen-like (H9O4+) structure for the bridging water molecule, leading directly to the formation of the products. A second structure of the bridging water molecule is also observed, which is a Zündel-like (H5O2+) configuration involving the proton acceptor (carboxylate ion), which seems to act as a dead-end for the proton transfer reaction.
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Gravimetria por satélite aplicada à pesquisa mineral: estudo de casos no Brasil / Satellite gravimetry applied to mineral research: study of cases in BrazilDenis Klismam Santos Barbosa 19 April 2017 (has links)
O Brasil está entre os países que mais possuem riquezas minerais no mundo, tendo inclusive o ouro um papel importante em sua história nos séculos XVII e XVIII. Desde então, novas descobertas ocorreram e estudos geológicos e geofísicos foram realizados por universidades, empresas privadas e públicas. Destes estudos, dominam aqueles de escala local, com o objetivo de identificar novos depósitos minerais em detrimento dos estudos regionais, com objetivo de estudar a gênese e evolução da província. De modo a contribuir com os estudos regionais, o presente trabalho analisou a aplicabilidade dos modelos que utilizam dados de gravimetria por satélite e determinou qual modelo apresenta melhores resultados para estudo nas seguintes províncias minerais brasileiras: Alta Floresta, Carajás, Quadrilátero Ferrífero e Tapajós. Os modelos estudados foram: EGM96 (grau/ordem 360), EGM2008 (grau/ordem 2190/2159), EGM2008upto360 (grau/ordem 360), EIGEN-CG03C (grau/ordem 360) e go_cons_gcf_2_tim_r4 (grau/ordem 240), todos acessíveis de forma gratuita pelo portal ICGEM (International Centre for Global Earth Models). O efeito isostático de cargas litosféricas e sua contribuição para a anomalia Bouguer foram modelados com base na equação de deflexão da litosfera. De modo a removê- lo, a modelagem foi realizada para toda a América do Sul e seu efeito foi subtraído da anomalia Bouguer de cada província mineral estudada, resultando na grandeza denominada residual da anomalia Bouguer. Tanto os mapas de anomalia Bouguer como os mapas de residual da anomalia Bouguer foram comparados entre si e com dados terrestres, quando disponíveis na literatura, a fim de averiguar eventuais artefatos de processamento dos modelos que poderiam ser interpretados erroneamente. Perfis representativos também foram comparados, de modo a observar a amplitude relativa das anomalias de forma quantitativa. Os resultados obtidos mostram que há uma boa correlação em escala regional entre dados de satélite e terrestres nas províncias Alta Floresta e Quadrilátero Ferrífero para todos os modelos estudados, fato que corrobora a aplicabilidade destes dados para a metodologia utilizada. O modelo que se mostrou mais adequado tanto em nível de detalhamento quanto em identificação de anomalias de menor comprimento de onda foi o EGM2008 principalmente para a província do Quadrilátero Ferrífero. Para o restante das províncias houve diferenças pouco significativas entre os modelos EGM2008 e EGM2008upto360, indicando que para estas regiões as anomalias associadas a grau e ordem superiores a 360 pouco influenciam nos mapas de residual e de anomalia Bouguer em escala regional. O modelo que menos se adequa ao estudo nas áreas estudadas é o go_cons_gcf_2_tim_r4, provavelmente porque, além de possuir os menores grau e ordem dentre os modelos estudados, é o único que utiliza apenas dados de satélite em sua elaboração. A partir dos dados de anomalia Bouguer e, principalmente, de residual da anomalia Bouguer é possível observar correlação sistemática entre altos anômalos e a localização das minas para as províncias de Quadrilátero Ferrífero e Alta Floresta. Essa correlação vista a partir de dados de acesso gratuito permite definir regiões de interesse exploratório em escala local, melhorando a eficiência e eficácia dos recursos já escassos na exploração mineral brasileira. / Brazil is one of the countries that possess most mineral riches in the world: gold, for example, has played an important role in its history in the seventeenth and eighteenth centuries. Since then, new discoveries have occurred and geological and geophysical studies have been carried out by universities, private and public companies. These studies are mainly of local scale, focusing on identifying new mineral deposits instead of regional studies, which focus on the genesis and evolution of the province. In order to contribute to the regional studies, the present work analyzed the applicability of the models that use satellite gravimetry data and determined which model presents the best results in the following Brazilian mineral provinces: Alta Floresta, Carajás, Quadrilátero Ferrífero and Tapajós. The models studied were EGM96 (degree / order 360), EGM2008 (degree / order 2190/2159), EGM2008upto360 (degree / order 360), EIGEN-CG03C (degree / order 360) and go_cons_gcf_2_tim_r4 (degree / order 240), each of them accessible by ICGEM (International Center for Global Earth Models) portal. The isostatic effect of the lithospheric loads and their contribution to the Bouguer anomaly were modeled based on the lithosphere deflection equation. In order to remove it, the modeling was carried out for the entire South America territory and its effect was subtracted from the Bouguer anomaly of each studied mineral province, resulting in the residual Bouguer anomaly. Both Bouguer and the residual Bouguer anomalies were compared to each other and to terrestrial data when available in the literature to ascertain possible processing artifacts that could be misinterpreted. Representative profiles were also compared in order to observe the relative amplitude of the anomalies quantitatively. The results show that, for example, there is a good regional correlation between satellite and terrestrial data in the Alta Floresta and Quadrilátero Ferrífero provinces for all the models studied, which corroborates the applicability of these data to the methodology used. The most appropriated model regarding the level of detail and the identification of shorter wavelength anomalies was the EGM2008 specially for the Quadrilátero Ferrífero province. For the remaining provinces there were slight differences between the EGM2008 and EGM2008upto360 models, indicating that for these regions anomalies associated with degree and order higher than 360 have little influence to the Bouguer and residual Bouguer anomalies on a regional scale. The model least suitable for the studied areas is go_cons_gcf_2_tim_r4, probably because, in addition to having the lowest degree and order among the studied models, it is the only one that uses only satellite data in its elaboration. From the Bouguer anomaly and specially from residual Bouguer anomaly it is possible to observe systematic correlation between anomalous highs and the location of the mines for the provinces of Quadrilátero Ferrífero and Alta Floresta. This correlation, based on free access data, allows the definition of regions of exploratory interest at a local scale, improving the efficiency and effectiveness of resources already scarce in Brazilian mineral exploration.
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Gravimetria por satélite aplicada à pesquisa mineral: estudo de casos no Brasil / Satellite gravimetry applied to mineral research: study of cases in BrazilBarbosa, Denis Klismam Santos 19 April 2017 (has links)
O Brasil está entre os países que mais possuem riquezas minerais no mundo, tendo inclusive o ouro um papel importante em sua história nos séculos XVII e XVIII. Desde então, novas descobertas ocorreram e estudos geológicos e geofísicos foram realizados por universidades, empresas privadas e públicas. Destes estudos, dominam aqueles de escala local, com o objetivo de identificar novos depósitos minerais em detrimento dos estudos regionais, com objetivo de estudar a gênese e evolução da província. De modo a contribuir com os estudos regionais, o presente trabalho analisou a aplicabilidade dos modelos que utilizam dados de gravimetria por satélite e determinou qual modelo apresenta melhores resultados para estudo nas seguintes províncias minerais brasileiras: Alta Floresta, Carajás, Quadrilátero Ferrífero e Tapajós. Os modelos estudados foram: EGM96 (grau/ordem 360), EGM2008 (grau/ordem 2190/2159), EGM2008upto360 (grau/ordem 360), EIGEN-CG03C (grau/ordem 360) e go_cons_gcf_2_tim_r4 (grau/ordem 240), todos acessíveis de forma gratuita pelo portal ICGEM (International Centre for Global Earth Models). O efeito isostático de cargas litosféricas e sua contribuição para a anomalia Bouguer foram modelados com base na equação de deflexão da litosfera. De modo a removê- lo, a modelagem foi realizada para toda a América do Sul e seu efeito foi subtraído da anomalia Bouguer de cada província mineral estudada, resultando na grandeza denominada residual da anomalia Bouguer. Tanto os mapas de anomalia Bouguer como os mapas de residual da anomalia Bouguer foram comparados entre si e com dados terrestres, quando disponíveis na literatura, a fim de averiguar eventuais artefatos de processamento dos modelos que poderiam ser interpretados erroneamente. Perfis representativos também foram comparados, de modo a observar a amplitude relativa das anomalias de forma quantitativa. Os resultados obtidos mostram que há uma boa correlação em escala regional entre dados de satélite e terrestres nas províncias Alta Floresta e Quadrilátero Ferrífero para todos os modelos estudados, fato que corrobora a aplicabilidade destes dados para a metodologia utilizada. O modelo que se mostrou mais adequado tanto em nível de detalhamento quanto em identificação de anomalias de menor comprimento de onda foi o EGM2008 principalmente para a província do Quadrilátero Ferrífero. Para o restante das províncias houve diferenças pouco significativas entre os modelos EGM2008 e EGM2008upto360, indicando que para estas regiões as anomalias associadas a grau e ordem superiores a 360 pouco influenciam nos mapas de residual e de anomalia Bouguer em escala regional. O modelo que menos se adequa ao estudo nas áreas estudadas é o go_cons_gcf_2_tim_r4, provavelmente porque, além de possuir os menores grau e ordem dentre os modelos estudados, é o único que utiliza apenas dados de satélite em sua elaboração. A partir dos dados de anomalia Bouguer e, principalmente, de residual da anomalia Bouguer é possível observar correlação sistemática entre altos anômalos e a localização das minas para as províncias de Quadrilátero Ferrífero e Alta Floresta. Essa correlação vista a partir de dados de acesso gratuito permite definir regiões de interesse exploratório em escala local, melhorando a eficiência e eficácia dos recursos já escassos na exploração mineral brasileira. / Brazil is one of the countries that possess most mineral riches in the world: gold, for example, has played an important role in its history in the seventeenth and eighteenth centuries. Since then, new discoveries have occurred and geological and geophysical studies have been carried out by universities, private and public companies. These studies are mainly of local scale, focusing on identifying new mineral deposits instead of regional studies, which focus on the genesis and evolution of the province. In order to contribute to the regional studies, the present work analyzed the applicability of the models that use satellite gravimetry data and determined which model presents the best results in the following Brazilian mineral provinces: Alta Floresta, Carajás, Quadrilátero Ferrífero and Tapajós. The models studied were EGM96 (degree / order 360), EGM2008 (degree / order 2190/2159), EGM2008upto360 (degree / order 360), EIGEN-CG03C (degree / order 360) and go_cons_gcf_2_tim_r4 (degree / order 240), each of them accessible by ICGEM (International Center for Global Earth Models) portal. The isostatic effect of the lithospheric loads and their contribution to the Bouguer anomaly were modeled based on the lithosphere deflection equation. In order to remove it, the modeling was carried out for the entire South America territory and its effect was subtracted from the Bouguer anomaly of each studied mineral province, resulting in the residual Bouguer anomaly. Both Bouguer and the residual Bouguer anomalies were compared to each other and to terrestrial data when available in the literature to ascertain possible processing artifacts that could be misinterpreted. Representative profiles were also compared in order to observe the relative amplitude of the anomalies quantitatively. The results show that, for example, there is a good regional correlation between satellite and terrestrial data in the Alta Floresta and Quadrilátero Ferrífero provinces for all the models studied, which corroborates the applicability of these data to the methodology used. The most appropriated model regarding the level of detail and the identification of shorter wavelength anomalies was the EGM2008 specially for the Quadrilátero Ferrífero province. For the remaining provinces there were slight differences between the EGM2008 and EGM2008upto360 models, indicating that for these regions anomalies associated with degree and order higher than 360 have little influence to the Bouguer and residual Bouguer anomalies on a regional scale. The model least suitable for the studied areas is go_cons_gcf_2_tim_r4, probably because, in addition to having the lowest degree and order among the studied models, it is the only one that uses only satellite data in its elaboration. From the Bouguer anomaly and specially from residual Bouguer anomaly it is possible to observe systematic correlation between anomalous highs and the location of the mines for the provinces of Quadrilátero Ferrífero and Alta Floresta. This correlation, based on free access data, allows the definition of regions of exploratory interest at a local scale, improving the efficiency and effectiveness of resources already scarce in Brazilian mineral exploration.
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Generalized Hebbian Algorithm for Dimensionality Reduction in Natural Language ProcessingGorrell, Genevieve January 2006 (has links)
The current surge of interest in search and comparison tasks in natural language processing has brought with it a focus on vector space approaches and vector space dimensionality reduction techniques. Presenting data as points in hyperspace provides opportunities to use a variety of welldeveloped tools pertinent to this representation. Dimensionality reduction allows data to be compressed and generalised. Eigen decomposition and related algorithms are one category of approaches to dimensionality reduction, providing a principled way to reduce data dimensionality that has time and again shown itself capable of enabling access to powerful generalisations in the data. Issues with the approach, however, include computational complexity and limitations on the size of dataset that can reasonably be processed in this way. Large datasets are a persistent feature of natural language processing tasks. This thesis focuses on two main questions. Firstly, in what ways can eigen decomposition and related techniques be extended to larger datasets? Secondly, this having been achieved, of what value is the resulting approach to information retrieval and to statistical language modelling at the ngram level? The applicability of eigen decomposition is shown to be extendable through the use of an extant algorithm; the Generalized Hebbian Algorithm (GHA), and the novel extension of this algorithm to paired data; the Asymmetric Generalized Hebbian Algorithm (AGHA). Several original extensions to the these algorithms are also presented, improving their applicability in various domains. The applicability of GHA to Latent Semantic Analysisstyle tasks is investigated. Finally, AGHA is used to investigate the value of singular value decomposition, an eigen decomposition variant, to ngram language modelling. A sizeable perplexity reduction is demonstrated.
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Separação cega de fontes em tempo real utilizando FPGAFratini Filho, Oswaldo January 2017 (has links)
Orientador: Prof. Dr. Ricardo Suyama / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2017. / O metodo estatistico de Independent Component Analysis (ICA) e um dos mais
amplamente utilizados para solucionar o problema de Blind Source Separation (BSS)
que, junto a outros metodos de processamento de sinais, sao colocados a prova com o
aumento do numero das fontes de sinais e amostras disponiveis para processamento,
e sao a base de aplicacoes com requisitos de desempenho cada vez maiores.
O objetivo deste trabalho e realizar o estudo do metodo ICA e analise dos algoritmos
FastICA e Joint Approximate Diagonalization of Eigen-matrices (JADE)
implementados em Field-Programmable Gate Array (FPGA) e seu comportamento
quando variamos o numero de amostras das misturas e os numeros de iteracoes ou
updates. Outros trabalhos de pesquisa ja foram realizados com o objetivo de demonstrar
a viabilidade da implementacao de tais algoritmos em FPGA, mas pouco
apresentam sobre o metodo utilizado para definir detalhes de implementacao como
numero de amostradas utilizados, a razao da representacao numerica escolhida e
sobre o thoughtput alcancado.
A analise que este trabalho propos realizar, num primeiro momento, passa por
demonstrar o comportamento do core dos algoritmos quando implementados utilizando
diferentes representacoes numericas de ponto flutuante com precisao simples
(32 bits) e ponto fixo com diferentes numeros de amostras e fontes a serem estimadas,
por meio de simulacoes. Foi verificada a viabilidade desses serem utilizados
para atender aplicacoes que precisam resolver o problema de BSS com boa acuracia,
quando comparados com implementacoes dos mesmos algoritmos que se utilizaram
de uma representacao numerica de ponto flutuante com precisao dupla (64 bits).
Utilizando o Simulink R¿e a biblioteca DSP Builder R¿da Altera R¿para implementar
os modelos de cada algoritmo, foi possivel analisar outros aspectos importantes, em
busca de demonstrar a possibilidade da utilizacao de tais implementacoes em aplicacoes
com requisitos de tempo real, que necessitam de alto desempenho, utilizando
FPGA de baixo custo, como: a quantidade de recursos de FPGA necessarios na
implementacao de cada algoritmo, principalmente buscando minimizar a utilizacao
de blocos DSP, a latencia, e maximizar o throughput de processamento. / Independent Component Analysis (ICA) is one of the most widely used statistical
method to solve the problem of Blind Source Separation (BSS), which, along
with other signal processing methods, faces new challenges with the increasing the
number of signal sources and samples available for processing, being the base of
applications with increasing performance requirements.
The aim of this work is to study the FastICA and the Joint Approximate Diagonalization
of Eigen-matrices (JADE) algorithms and implement them in Field-
Programmable Gate Array (FPGA). Other researches have already been carried out
with the objective of demonstrating the feasibility of implementing such algorithms
in FPGA, but they present little about the methodology used and implementation
details such as the number of samples used, why the numerical representation was
chosen and the obtained thoughtput.
The analysis carried out in this work demonstrates the behavior of the core of
the algorithms when implemented using different representations, such as singleprecision
floating-point (32 bits) and fixed point with different numbers of samples
and sources to be estimated. It was verified these immplementations are able to solve
the BSS problem with good accuracy when compared with implementations of the
same algorithms that exmploy a double-precision floating-point representation (64
bits).
Using the Simulink R¿ and Alterafs R¿ DSP Builder R¿ library to implement the models
of each algorithm, it was possible to analyze other important aspects, in order
to demonstrate the possibility of using such implementations in applications with
real-time requirements that require high performance, using low cost FPGA, such
as: the necessary FPGA resources in the implementation of each algorithm, mainly
seeking to minimize the use of DSP blocks, latency, and to maximize the processing
throughput.
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