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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.
241

Design and Analysis of Four Architectures for FPGA-Based Cellular Computing

Morgan, Kenneth J. 09 November 2004 (has links)
The computational abilities of today's parallel supercomputers are often quite impressive, but these machines can be impractical for some researchers due to prohibitive costs and limited availability. These researchers might be better served by a more personal solution such as a "hardware acceleration" peripheral for a PC. FPGAs are the ideal device for the task: their configurability allows a problem to be translated directly into hardware, and their reconfigurability allows the same chip to be reprogrammed for a different problem. Efficient FPGA computation of parallel problems calls for cellular computing, which uses an array of independent, locally connected processing elements, or cells, that compute a problem in parallel. The architecture of the computing cells determines the performance of the FPGA-based computer in terms of the cell density possible and the speedup over conventional single-processor computation. This thesis presents the design and performance results of four computing-cell architectures. MULTIPLE performs all operations in one cycle, which takes the least amount of time but requires the most chip area. BIT performs all operations bit-serially, which takes a long time but allows a large cell density. The two other architectures, SINGLE and BOOTH, lie within these two extremes of the area/time spectrum. The performance results show that MULTIPLE provides the greatest speedup over common calculation software, but its usefulness is limited by its small cell density. Thus, the best architecture for a particular problem depends on the number of computing cells required. The results also show that with further research, next-generation FPGAs can be expected to accelerate single-processor computations as much as 22,000 times. / Master of Science
242

Etudes de nanostructures magnétiques auto-organisées et épitaxiées par synthèse organométallique en solution sur des surfaces cristallines / Studies on auto-organized and epitaxiated magnetic nanostructures obtained by organometallic synthesis in solution on crystalline surfaces

Achkar, Charbel 04 July 2014 (has links)
Les travaux élaborés dans cette thèse ont pour objectif de caractériser les propriétés magnétiques et structurales de nanostructures magnétiques obtenues par une nouvelle méthode de synthèse mixte physique/chimique, dite croissance hybride. La première partie du travail réalisé consiste en l’élaboration de films minces métalliques sur substrats par pulvérisation cathodique. Sur ces films minces, la synthèse chimique par voie organométallique aboutit à des réseaux de nanofils de Co monocristallins hcp, ultra-denses, ou des films nanostructurés de Fe. Les observations MEB/MET et les mesures de diffraction de rayons X réalisées sur les substrats montrent le fort impact induit par la cristallinité de la couche mince sur la morphologie et la direction de croissance des nanostructures magnétiques.Les mesures magnétiques réalisées sur des réseaux de nanofils de Co montrent une forte anisotropie magnétique perpendiculaire au substrat. Cela est obtenu grâce à l’anisotropie magnétocristalline du Co hcp (avec l’axe c parallèle à l’axe du fil) qui s’ajoute à l’anisotropie de forme. L’aimantation thermiquement stable, semble suivre un régime de retournement cohérent, régime non observé dans les structures polycristallines. L’organisation de ces nanostructures, leur grande densité et la stabilité de leur aimantation font de ce réseau un bon candidat aux applications de médias d’enregistrement magnétique à forte densité. / The elaboration of this thesis aims to characterize the magnetic and structural properties of magnetic nanostructures obtained by a new mixed physical / chemical synthesis method, called hybrid growth. The first part of the work consists in the development of thin metal films on substrates by cathode sputtering. Furthermore, the chemical synthesis conducted by organometallic chemistry on those thin films, results in an array of ultra-dense Co monocristallins hcp nanowires, or nanostructured Fe films. Additionally, The SEM/TEM observations and the X-ray diffraction measurements conducted on the substrates and induced by the crystlalline structure of the thin film, show the high impact on the magnetic nanostructures morphology and growth direction.Moreover, the magnetic measurements executed on the Co nanowires array show a strong magnetic anisotropy perpendicular to the substrate. This observation is obtained due to the magnetocrystalline anisotropy acting along the nanowire axis (Co hcp structure with the c axis parallel to the nanowire axis) in the same direction of the nanowires shape anisotropy. The magnetization within these structures is thermally stable. It follows a coherent magnetization reversal mode that has not been observed in the polycrystalline structures up to now. Finally, the self-organization of the nanowires as well as their high density and stable magnetization nominate this system for their application in high density magnetic storage devices.
243

Ochrana investic na základě dvoustranné ochrané investiční smlouvy mezi Thajskem a Českou republikou / Protection of Investments under the Bilateral Investment Treaty between Thailand and the Czech Republic

Tanchinwuttanakul, Kamol January 2017 (has links)
The commercial and investment relations between Thailand and the Czech Republic are longstanding. Currently, the Czech Republic imports a number of agricultural products and food from Thailand, and Thailand imports industrial technology from the Czech Republic. As a result, there are opportunities for Czech companies to invest in and establish business cooperation with Thai businesses with agreements to guarantee stable commercial investment relations between Thailand and the Czech Republic. Because of this, the Bilateral Investment Treaty (BIT) between both countries facilitates further development. The dissertation deals with research about the Protection of Investments under the Bilateral Investment Treaty between Thailand and the Czech Republic. The first BIT between Thailand and the Czech Republic was the 'Agreement between the Government of the Czech and Slovak Federal Republic and the Government of the Kingdom of Thailand for the Promotion and Protection of Investments (1991)' which was replaced by the 'Agreement between the Government of the Kingdom of Thailand and the Government of the Czech Republic for the Promotion and Protection of Investments (1994) (BIT between Thailand and the Czech Republic 1994), and this BIT is still in force and has not been modified or amended. The object of...
244

Filtros para a busca e extração de padrões aproximados em cadeias biológicas / Filter Algorithms for Approximate Patterns Matching and Extraction from Biological Strings

Soares Neto, Domingos 10 September 2008 (has links)
Esta dissertação de mestrado aborda formulações computacionais e algoritmos para a busca e extração de padrões em cadeias biológicas. Em particular, o presente texto concentra-se nos dois problemas a seguir, considerando-os sob as distâncias de Hamming e Levenshtein: a) como determinar os locais nos quais um dado padrão ocorre de modo aproximado em uma cadeia fornecida; b) como extrair padrões que ocorram de modo aproximado em um número significativo de cadeias de um conjunto fornecido. O primeiro problema, para o qual já existem diversos algoritmos polinomiais, tem recebido muita atenção desde a década de 60, e ganhou novos ares com o advento da biologia computacional, nos idos dos anos 80, e com a popularização da Internet e seus mecanismos de busca: ambos os fenômenos trouxeram novos obstáculos a serem superados, em razão do grande volume de dados e das bastante justas restrições de tempo inerentes a essas aplicações. O segundo problema, de surgimento um pouco mais recente, é intrinsicamente desafiador, em razão de sua complexidade computacional, do tamanho das entradas tratadas nas aplicações mais comuns e de sua dificuldade de aproximação. Também é de chamar a atenção o seu grande potencial de aplicação. Neste trabalho são apresentadas formulações adequadas dos problemas abordados, assim como algoritmos e estruturas de dados essenciais ao seu estudo. Em especial, estudamos a extremamente versátil árvore dos sufixos, assim como uma de suas generalizações e sua estrutura irmã: o vetor dos sufixos. Grande parte do texto é dedicada aos filtros baseados em q-gramas para a busca aproximada de padrões e algumas de suas mais recentes variações. Estão cobertos os algoritmos bit-paralelos de Myers e Baeza-Yates-Gonnet para a busca de padrões; os algoritmos de Sagot para a extração de padrões; os algoritmos de filtragem de Ukkonen, Jokinen-Ukkonen, Burkhardt-Kärkkäinen, entre outros. / This thesis deals with computational formulations and algorithms for the extraction and search of patterns from biological strings. In particular, the present text focuses on the following problems, both considered under Hamming and Levenshtein distances: 1. How to find the positions where a given pattern approximatelly occurs in a given string; 2. How to extract patterns which approximatelly occurs in a certain number of strings from a given set. The first problem, for which there are many polinomial time algorithms, has been receiving a lot of attention since the 60s and entered a new era of discoveries with the advent of computational biology, in the 80s, and the widespread of the Internet and its search engines: both events brought new challenges to be faced by virtue of the large volume of data usually held by such applications and its time constraints. The second problem, much younger, is very challenging due to its computational complexity, approximation hardness and the size of the input data usually held by the most common applications. This problem is also very interesting due to its potential of application. In this work we show computational formulations, algorithms and data structures for those problems. We cover the bit-parallel algorithms of Myers, Baeza-Yates-Gonnet and the Sagots algorithms for patterns extraction. We also cover here the oustanding versatile suffix tree, its generalised version, and a similar data structure: the suffix array. A significant part of the present work focuses on q-gram based filters designed to solve the approximate pattern search problem. More precisely, we cover the filter algorithms of Ukkonen, Jokinen-Ukkonen and Burkhardt-Kärkkäinen, among others.
245

An 8-bit, 12.5GS/s Folding-interpolating Analog-to-digital Converter

Ghetmiri, Shohreh 10 August 2009 (has links)
The motivation behind this work is to target the demand for high-speed medium-resolution ADCs for satellite communication systems. An 8-bit, 12.5GS/s folding-interpolating ADC was designed in 0.25µm, 190GHz SiGe BiCMOS technology from IHP. The ADC consists of a THA, a reference resistor ladder, folding amplifiers, an interpolating resistor string, a comparator array, a digital encoder, a coarse quantizer and a bit synchronizer. Post-layout simulation results of the ADC verify that its performance meets all the required specifications. By comparison to other high-speed ADCs, implemented in SiGe technologies, the present design features the highest sampling rate for 8-bit resolution ADCs to date with a good FOM (12.9pJ/conversion). The THA and the comparator were implemented experimentally and characterized to verify their performance and to ascertain the possibility of implementing the complete ADC. The experimental results meet the expected specifications and indicate that both circuits are suitable for the implementation of the ADC.
246

LNG träningsmanual för M/T Bit Viking / LNG training manual : According to MSC.285 86/26/Add.1 Annex 11

Albertsson, Robin, Hermansson, Joakim January 2013 (has links)
Denna uppsats är gjord på uppdrag av Tarbit Shipping som år 2011 konverterade sin tankbåt M/T Bit Viking från konventionell drift på tjockolja till LNG (Liquefied Natural Gas).Uppdraget som gavs var att upprätta en tränings manual till fartyget då det är ett krav från IMO (International Maritime Organization). Manualen skrevs i 3 st huvuddelar Kategori A, B och C. Kategori A är till för att manskap ombord ska få en kännedom om gasen och säkerhet runt den, Kategori B är skriven till däcksbefäl där det krävs en större kännedom om gasen och Kategori C är till för maskinbefäl. Manualen finns nu ombord på fartyget och på rederi kontoret för utbildning av nypåmönstrad personal och fortlöpande utbildning av ordinarie personal. Manualen är ett resultat på tolkning av IMO´s IGF kod (ANNEX11. RESOLUTION MSC.285(86)) där det står riktlinjer för säkerheten ombord på fartyg med maskiner som drivs på naturgas. / This paper has been produced as a result of an assignment set by Tarbit Shipping which 2011converted one of their product tanker ships from M/T Bit Viking its original heavy fuel oil toLNG (Liquefied Natural Gas). The assignment was to establish a training manual to the shipaccording to IMO´s (International Maritime Organization) IGF code. The manual is written inthree main parts Category A, Category B and Category C. Category A is directed at ratingsand cadets and focuses on gas and safety procedures, Category B is directed at deck officersand focuses on gas, whilst Category C is directed at engine officers and, similar to Category Baims at increasing knowledge levels for engineers. The manual is now located onboard theship and at the company’s office for education of new personnel and for continued educationfor personnel onboard. The manual is a result on an interpretation of IMO´s IGF code(ANNEX11. RESOLUTION MSC.285(86)), in which guidelines are laid out for vesselsfueled by natural gas.
247

An 8-bit, 12.5GS/s Folding-interpolating Analog-to-digital Converter

Ghetmiri, Shohreh 10 August 2009 (has links)
The motivation behind this work is to target the demand for high-speed medium-resolution ADCs for satellite communication systems. An 8-bit, 12.5GS/s folding-interpolating ADC was designed in 0.25µm, 190GHz SiGe BiCMOS technology from IHP. The ADC consists of a THA, a reference resistor ladder, folding amplifiers, an interpolating resistor string, a comparator array, a digital encoder, a coarse quantizer and a bit synchronizer. Post-layout simulation results of the ADC verify that its performance meets all the required specifications. By comparison to other high-speed ADCs, implemented in SiGe technologies, the present design features the highest sampling rate for 8-bit resolution ADCs to date with a good FOM (12.9pJ/conversion). The THA and the comparator were implemented experimentally and characterized to verify their performance and to ascertain the possibility of implementing the complete ADC. The experimental results meet the expected specifications and indicate that both circuits are suitable for the implementation of the ADC.
248

Desenvolvimento de um WebLab para estudo e caracterização de sistemas WDM

Antonio, Erik Aceiro 30 June 2008 (has links)
Made available in DSpace on 2016-04-18T21:39:47Z (GMT). No. of bitstreams: 4 Erik Aceiro Antonio1.pdf: 1548083 bytes, checksum: 089690da04ba664ec23f802cb3975826 (MD5) Erik Aceiro Antonio2.pdf: 1618157 bytes, checksum: efefcd4d6d658d457615e8757d4175d8 (MD5) Erik Aceiro Antonio3.pdf: 2722615 bytes, checksum: a3f70f5fd3c8b07408a62f1d5a6cfbc2 (MD5) Erik Aceiro Antonio4.pdf: 1214557 bytes, checksum: 8bf6858d70baeb72941ce7c5cc104437 (MD5) Previous issue date: 2008-06-30 / The advent of the Internet and the development of Information and Communication Technologies (ICT s)generated new spaces for communication and collaboration between groups of people in geographically distinct regions. The association of Web technology with instrument automation and control by computer has made possible the development of the so called Remote Laboratories or WebLabs - distributed environments that allow to access and control experiments remotely through a network or the Internet in real time and with the sensation of presence. In this work, a WebLab was developed for the study and caracterization of a WDM (Wave Division Multiplexing) system, aiming to support and complement activities in faceto-face and distance courses on Optical Communications. Drivers and graphic user interfaces (GUI s) were developed with the software LabVIEW for control and data acquisition of instruments used in a remote experiment to measure the basic features of a WDM system. An application was also developed with the software VPI for the numerical simulation of Bit Error Rate (BER) measurements. This work is part of the activities related to the participation of the Mackenzie Photonics Laboratory in the KyaTera Project of FAPESP s TIDIA Program. / O advento da Internet e o desenvolvimento das Tecnologias da Informação e Comunicação (TIC s) geraram novos espaços para a comunicação e colaboração entre grupos de pessoas localizadas em regiões geograficamente distintas. A associação da tecnologiaWeb com a automação e controle de instrumentos por computador tornou possível o desenvolvimento dos chamados Laboratórios Remotos ou WebLabs - ambientes distribuídos que permitem o acesso e controle remoto de experimentos através de uma rede de comunicação ou da Internet em tempo real e com sensação de presença. Neste trabalho, foi desenvolvido um WebLab para estudo e caracterização de um sistema WDM (Wave Division Multiplexing), destinado a apoiar e complementar atividades em cursos de Comunicações Ópticas presenciais e a distância. Foram desenvolvidos drivers e interfaces gráficas de usuário (GUI s) com o software LabVIEW para o controle e aquisição de dados dos instrumentos utilizados em um experimento remoto de medida das características básicas de um sistema WDM. Também foi desenvolvido um aplicativo com o software VPI que permite simular a medida da Taxa de Erro de Bit (BER) do sistema. Este trabalho é parte das atividades relacionadas à participação do Laboratório de Fotônica Mackenzie no Projeto KyaTera do Programa TIDIA da FAPESP.
249

Filtros para a busca e extração de padrões aproximados em cadeias biológicas / Filter Algorithms for Approximate Patterns Matching and Extraction from Biological Strings

Domingos Soares Neto 10 September 2008 (has links)
Esta dissertação de mestrado aborda formulações computacionais e algoritmos para a busca e extração de padrões em cadeias biológicas. Em particular, o presente texto concentra-se nos dois problemas a seguir, considerando-os sob as distâncias de Hamming e Levenshtein: a) como determinar os locais nos quais um dado padrão ocorre de modo aproximado em uma cadeia fornecida; b) como extrair padrões que ocorram de modo aproximado em um número significativo de cadeias de um conjunto fornecido. O primeiro problema, para o qual já existem diversos algoritmos polinomiais, tem recebido muita atenção desde a década de 60, e ganhou novos ares com o advento da biologia computacional, nos idos dos anos 80, e com a popularização da Internet e seus mecanismos de busca: ambos os fenômenos trouxeram novos obstáculos a serem superados, em razão do grande volume de dados e das bastante justas restrições de tempo inerentes a essas aplicações. O segundo problema, de surgimento um pouco mais recente, é intrinsicamente desafiador, em razão de sua complexidade computacional, do tamanho das entradas tratadas nas aplicações mais comuns e de sua dificuldade de aproximação. Também é de chamar a atenção o seu grande potencial de aplicação. Neste trabalho são apresentadas formulações adequadas dos problemas abordados, assim como algoritmos e estruturas de dados essenciais ao seu estudo. Em especial, estudamos a extremamente versátil árvore dos sufixos, assim como uma de suas generalizações e sua estrutura irmã: o vetor dos sufixos. Grande parte do texto é dedicada aos filtros baseados em q-gramas para a busca aproximada de padrões e algumas de suas mais recentes variações. Estão cobertos os algoritmos bit-paralelos de Myers e Baeza-Yates-Gonnet para a busca de padrões; os algoritmos de Sagot para a extração de padrões; os algoritmos de filtragem de Ukkonen, Jokinen-Ukkonen, Burkhardt-Kärkkäinen, entre outros. / This thesis deals with computational formulations and algorithms for the extraction and search of patterns from biological strings. In particular, the present text focuses on the following problems, both considered under Hamming and Levenshtein distances: 1. How to find the positions where a given pattern approximatelly occurs in a given string; 2. How to extract patterns which approximatelly occurs in a certain number of strings from a given set. The first problem, for which there are many polinomial time algorithms, has been receiving a lot of attention since the 60s and entered a new era of discoveries with the advent of computational biology, in the 80s, and the widespread of the Internet and its search engines: both events brought new challenges to be faced by virtue of the large volume of data usually held by such applications and its time constraints. The second problem, much younger, is very challenging due to its computational complexity, approximation hardness and the size of the input data usually held by the most common applications. This problem is also very interesting due to its potential of application. In this work we show computational formulations, algorithms and data structures for those problems. We cover the bit-parallel algorithms of Myers, Baeza-Yates-Gonnet and the Sagots algorithms for patterns extraction. We also cover here the oustanding versatile suffix tree, its generalised version, and a similar data structure: the suffix array. A significant part of the present work focuses on q-gram based filters designed to solve the approximate pattern search problem. More precisely, we cover the filter algorithms of Ukkonen, Jokinen-Ukkonen and Burkhardt-Kärkkäinen, among others.
250

Simulation multi-moteurs multi-niveaux pour la validation des spécifications système et optimisation de la consommation / Multi-engine multi-level simulation for system specification validation and power consumption optimization

Li, Fangyan 29 March 2016 (has links)
Ce travail vise la modélisation au niveau système, en langage SystemC-AMS, et la simulation d'un émetteur-récepteur au standard Bluetooth Low Energy (BLE). L'objectif est d'analyser la relation entre les performances, en termes de BER et la consommation d'énergie du transceiver. Le temps de simulation d’un tel système, à partir de cas d’étude (use case) réaliste, est un facteur clé pour le développement d’une telle plateforme. De plus, afin d’obtenir des résultats de simulation le plus précis possible, les modèles « haut niveau » doivent être raffinés à partir de modèles plus bas niveau où de mesure. L'approche dite Meet-in-the-Middle, associée à la méthode de modélisation équivalente en Bande Base (BBE, BaseBand Equivalent), a été choisie pour atteindre les deux conditions requises, à savoir temps de simulation « faible » et précision des résultats. Une simulation globale d'un système de BLE est obtenue en intégrant le modèle de l'émetteur-récepteur dans une plateforme existante développée en SystemC-TLM. La simulation est basée sur un système de communication de deux dispositifs BLE, en utilisant différents scénarios (différents cas d'utilisation de BLE). Dans un premier temps nous avons modélisé et validé chaque bloc d’un transceiver BT. Devant le temps de simulation prohibitif, les blocs RF sont réécrits en utilisant la méthodologie BB, puis raffinés afin de prendre en compte les non-linéarités qui vont impacter le couple consommation, BER. Chaque circuit (chaque modèle) est vérifié séparément, puis une première simulation système (point à point entre un émetteur et un récepteur) est effectuée / This work aims at system-level modelling a defined transceiver for Bluetooth Low energy (BLE) system using SystemC-AMS. The goal is to analyze the relationship between the transceiver performance and the accurate energy consumption. This requires the transceiver model contains system-level simulation speed and the low-level design block power consumption and other RF specifications. The Meet-in-the-Middle approach and the Baseband Equivalent method are chosen to achieve the two requirements above. A global simulation of a complete BLE system is achieved by integrating the transceiver model into a SystemC-TLM described BLE system model which contains the higher-than-PHY levels. The simulation is based on a two BLE devices communication system and is run with different BLE use cases. The transceiver Bit-Error-Rate and the energy estimation are obtained at the end of the simulation. First, we modelled and validated each block of a BT transceiver. In front of the prohibitive simulation time, the RF blocks are rewritten by using the BBE methodology, and then refined in order to take into account the non-linearities, which are going to impact the couple consumption, BER. Each circuit (each model) is separately verified, and then a first BLE system simulation (point-to-point between a transmitter and a receiver) has been executed. Finally, the BER is finally estimated. This platform fulfills our expectations, the simulation time is suitable and the results have been validated with the circuit measurement offered by Riviera Waves Company. Finally, two versions of the same transceiver architecture are modelled, simulated and compared

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