Spelling suggestions: "subject:"bias"" "subject:"bis""
41 |
INJECTION DE FAUTES SIMULANT LES EFFETS DE BASCULEMENT DE BITS INDUITS PAR RADIATIONFaure, F. 14 November 2005 (has links) (PDF)
Obtenir une estimation du taux d'erreurs induit par les phénomènes de basculement de bit (soft error<br />rate, SER) des équipements électroniques est d'un intérêt grandissant. Les standards publiés traitent principalement de la qualification des circuits de type mémoire. Il n'y a pas d'accord sur les méthodes de qualification des microprocesseurs. Dans ce contexte, cette thèse s'attache à définir une méthodologie permettant de prédire le SER d'un processeur à l'aide d'une approche en trois étapes: 1) En définissant une méthode de test sous radiation permettant d'obtenir de façon précise la sensibilité du circuit au rayonnement ionisant; 2) En présentant une analyse détaillée des mesures, dont le but est d'extraire un modèle statistique d'un test accéléré; 3) En utilisant cette empreinte statistique pour reproduire à l'aide d'injection de fautes le comportement du circuit étudié afin de prédire le comportement d'une application quelconque exécutée par le processeur.
|
42 |
Conception et réalisation d'une mémoire partagée répartieHan, Jay 25 November 1996 (has links) (PDF)
Arias est un système de mémoire partagée répartie (MPR) réalisé dans le cadre du projet SIRAC, qui étudie les supports logiciels pour les applications distribuées. Une MPR facilite grandement la programmation de telles applications. Nous retraçons l'évolution des systèmes distributés qui ont abouti à cette idée, et caractérisons les diverses particularités de quelques projets antérieurs. Nous édictons nos objectifs propres et dégageons les spécifications qui sont souhaitables pour notre projet. Partant de là, et après avoir esquissé l'architecture générale d'Arias, nous nous concentrons sur les problèmes liés à la répartition de la mémoire. En particulier, l'allocation et la localisation de la mémoire dans une MPR à grand espace d'adresses posent des difficultés de réalisation qui ont des conséquences importantes dans la conception de l'interface logicielle avec l'application et le système d'exploitation sous-jacent. L'analyse de ces difficultés nous mène au module d'allocation et de localisation que nous décrivons. Une fois son implémentation décrite dans ses détails techniques, nous en explicitons les paramètres d'ajustement et soulignons leur impact à travers des mesures et des simulations. Nous montrons plusieurs configurations envisageables, dont certaines sont spécialement adaptées à certains types d'utilisation. Pour finir, nous concluons sur les leçons apprises de ce travail, tant du point de vue de ce qui a été réalisé que sur les travaux futurs et les perspectives générales des MPR.
|
43 |
Implémentation d'un bit quantique dans un circuit supraconducteur / Implementation of a quantum bit in a superconducting circuitCottet, Audrey 30 September 2002 (has links) (PDF)
Il existe des projets d'ordinateurs quantiques pour résoudre certains problèmes difficiles, comme la factorisation des grands nombres, beaucoup plus rapidement qu'avec un ordinateur classique. L'unité de base de l'ordinateur quantique est un système quantique à deux niveaux nommé bit quantique, qui doit satisfaire des critères très stricts. Parmi les nombreux systèmes proposés pour réaliser un bit quantique, les circuits électroniques sont des candidats intéressants en raison de leur grande intégrabilité. L'objet ce cette thèse est de réaliser un bit quantique à partir d'un circuit supraconducteur à base de jonctions Josephson nommé ``boîte à paires de Cooper''. L'état de cette boîte peut être déterminé soit par une mesure de courant, soit par une mesure de charge. Dans cette thèse sont étudiées trois différentes stratégies pour réaliser le bit quantique, qui diffèrent par le mode de lecture de l'état de la boîte. Pour chaque stratégie, le temps de vie d'une superposition cohérente d'états de la boîte est évaluée théoriquement et l'appareil de mesure associé est testé expérimentalement. Cette étude permet de déterminer la stratégie la plus prometteuse qui est finalement implémentée dans ce travail de thèse sous le nom de ``quantronium''. L'état du quantronium a été manipulé à l'aide d'impulsions radiofréquence, et le temps de vie d'une superposition quantique d'états de ce circuit a été déterminée. Ce temps est suffisamment long pour envisager la construction de portes logiques élémentaires.
|
44 |
O uso de conhecimento especialista e base de dados na seleção de brocas de perfuração / The use of expert knowledge and data bank for drill bits selectionMendes, José Ricardo Pelaquim, 1971- 18 February 1998 (has links)
Orientador: Celso Kazuyuki Morooka / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-23T20:08:04Z (GMT). No. of bitstreams: 1
Mendes_JoseRicardoPelaquim_M.pdf: 6979997 bytes, checksum: cb7b7cacbcb91fb76e57ca2cad3585fc (MD5)
Previous issue date: 1998 / Resumo: Uma série de trabalhos desenvolvidos com o uso do conceito de Sistemas Inteligentes Distribuídos, criando agentes de raciocínio fornecido por especialistas em diversas áreas do Petróleo, implementadas em um shell específico (Kards), tem vislumbrado um grande potencial do uso desta tecnologia no ramo do Petróleo. Na seleção de brocas para a perfuração de poços de Petróleo, o objetivo é alcançar um mínimo custo métrico, sendo a seleção na prática realizada através de poços de correlação e na própria experiência do engenheiro de perfuração. O uso de métodos analíticos geralmente necessitam de informações expendiosas além de ser uma tarefa árdua devido a complexibilidade do problema. Nesta dissertação é apresentado um método de preservação do conhecimento especializado no processo de seleção de brocas tricônicas através de redes neurais, lógica nebulosa e ferramentas disponíveis no Sistema Kards. Este trabalho serviu de base para arquitetar um Sistema Inteligente para o auxílio de seleção de brocas tricônicas, sendo útil também em termos de treinamento de novos engenheiros / Abstract: A series of works developed using the concept of Distributed Intelligent Systems, creating agents of reasoning provided by experts in several areas of Petroleum, structured in a specific shell (Kards), has glimpsed a great potencial of this technology in Petroleum sector. ln the bit selection to drill oil well, the objective is to obtain a minimum metric cost, being the selection in practice realized using correlation wells and in drilling engineers experience. The use of analytical methods usually needs extensive informations and moreover it is hard job owing to complexity of the problem. ln the thesis is presented a method of preservations of specialized knowledge jn triconics drills selection process using neural nets, fuzzy logic and available tools in the Kards System. This work was a base to construct an lntelligent System for the assistance of triconics drills selection, being also useful to fit to training of engineers / Mestrado / Mestre em Engenharia de Petróleo
|
45 |
[en] CONTRIBUITIONS TO IMPROVING CELP CODING AT LOW BIT RATS / [pt] CONTRIBUIÇÕES PARA A MELHORIA DA CODIFICAÇÃO CELP A BAIXAS TAXAS DE BITSLUCIO MARTINS DA SILVA 24 May 2006 (has links)
[pt] Esta tese propõe novas melhorias para a codificação CELP a
baixas taxas de bits. Primeiro, é proposto um algoritmo
CELP em que a complexidade do procedimento de busca no
dicionário adaptativo é grandemente reduzida, graças a uma
modificação introduzida no modelo de síntese CELP.
Resultados de simulação mostram que a qualidade da voz
codificada com o algoritmo CELP proposto tem qualidade
comparável àquela obtida com o algoritmo CELP convencional.
As demais contribuições têm o propósito de melhorar a
qualidade da voz codificada com o algoritmo CELP a baixas
taxas de bits. Uma delas propicia uma codificação mais
eficiente da envoltória espectral LPC da voz: é,
especificamente, um esquema que combina quantização
vetorial e interpolação interbloco dos parâmetros LSF. Com
este esquema a envoltória espectral LPC codificada tem boa
qualidade a uma taxa de bits tão baixa quanto 1 kb/s.
A voz codificada com os algoritmos CELP apresenta
freqüentemente distorções em sua envoltória espectral que
são causadas por deficiências do sinal de excitação. Esta
tese propõe um novo pós-filtro que reduz estas distorções
e, com isso, melhora significativamente a qualidade
subjetiva da voz codificada.
A baixas taxas de bits a estrutura CELP convencional é
incapaz de reproduzir com boa qualidade os ataques dos
sons sonoros, que são cruciais para uma boa percepção da
voz. Nesta tese é descrito um algoritmo CELP que dá
prioridade a estes segmentos críticos. Cada bloco da voz é
classificado em um dentre dezesseis padrões de sonoridade
e cada padrão tem uma configuração de codificação e
alocação de bits distintas. Resultados de simulação
mostram que a qualidade da voz codificada a 4 kb/s com o
algoritmo CELP proposto é significativamente melhor do que
aquela conseguida com um codificador CELP convencional,
também operando a 4 kb/s. / [en] This work presents new improvements to CELP speech coding
at low bit rates. First, a CELP algorithm is proposed in
wich the complexity of the adaptive codebook search is
gratly decreased. This is achieved by means of a modified
model of the CELP synthesizer. Simulation results show
that the proposed algorithm can provide speech quality
comparable to one obtained with the conventional CELP
codec.
The rest of contributions aim to improve the quality of
speech codec at low bit rates with CELP algorithm. One of
them is an efficient scheme for coding the LPC spectral
envelope of speech for coding the LPC spectral envelope of
speech. The proposed scheme combines vector quantization
and interpolation of LSF parameters, and it provides a
coded spectral envelope with very good quality at 1 kb/s.
Speech coded with CELP codecs frequently displays
distortions in its spectral envelope that are produced by
deficient excitation. This thesis proposes a new
postfilter that enhances the perceptual quality of codec
speech by decreasin these distortions.
This work presents new improvements to CELP speech coding
at low bit rates. First, a CELP algorithm is proposed in
wich the complexity of the adaptive codebook search is
gratly decreased. This is achieved by means of a modified
model of the CELP synthesizer. Simulation results show
that the proposed algorithm can provide speech quality
comparable to one obtained with the conventional CELP
codec.
The rest of contributions aim to improve the quality of
speech codec at low bit rates with CELP algorithm. One of
them is an efficient scheme for coding the LPC spectral
envelope of speech for coding the LPC spectral envelope of
speech. The proposed scheme combines vector quantization
and interpolation of LSF parameters, and it provides a
coded spectral envelope with very good quality at 1 kb/s.
Speech coded with CELP codecs frequently displays
distortions in its spectral envelope that are produced by
deficient excitation. This thesis proposes a new
postfilter that enhances the perceptual quality of codec
speech by decreasin these distortions.
Voiced onsets are crucial for a good perception of speech
but, at low bit rates, the conventional CELP is unable to
reproduce them with good quality. This work presents a
CELP algorithm into one of a set of sixteen voicing
patterns. A distinct coding configuration and bit
allocation are applied to each pattern. Simulation results
show that the quality of speech codec with the proposed 4
kb/s CELP codec is significantly bette than the one
obtained with conventional 4 kb/s CELP codec.
|
46 |
Säkerhetsanalys av Olofströms kommuns IT-verksamhet : En utvärdering av informationssäkerhetGöransson, Linus January 2013 (has links)
Uppsatsen syftar till att utvärdera informationssäkerheten i Olofströms kommuns IT-verksamhet för att jämföra resultatet med BITS. Vidare syfte med uppsatsen är att se över de övriga Blekingska kommunernas syn på informationssäkerhet samt hur de arbetar med det. Uppsatsen klarlägger även Olofströms kommuns anställdas syn på informationssäkerhet samt ger en sammanfattning hur deras dator-, lösenords- och e-posthantering ser ut. En tillsyn av Olofströms kommuns dokument "Säkerhetsinstruktion IT, för användare" genomförs för att utvärdera huruvida dokumentet uppnår en acceptabel säkerhetsnivå för informationshantering. Sammanfattningsvis visar resultaten att Olofströms kommun genomför ett aktivt arbete med informationssäkerhet. Resultaten visar även att de övriga Blekingska kommunerna anser att informationssäkerhet är viktigt och de jobbar någorlunda likvärdigt med det. Angående Olofströms kommuns dokument "Säkerhetsinstruktion IT, för användare" föreslås ett antal åtgärder som bör vidtas för att dokumentet ska vara à jour. Slutligen rekommenderas ett eventuellt samarbete mellan de Blekingska kommunerna för att ta fram ett gemensamt styrdokument för användarna.
|
47 |
Foreign direct investment in Tanzania : implications of bilateral investment treaties in promoting sustainable development in TanzaniaSinda, Aisha Ally 05 October 2010 (has links)
Many governments in developing countries including Tanzania have embarked upon an ambitious effort to conclude bilateral investment treaties. Bilateral investment treaties (BITs) are currently used as a famous means for establishing the legal framework for foreign investment in the world. BITs have been entered to by Tanzania mostly to improve the foreign investment climate and hence attract more foreign investment. Foreign investors are often worried about the quality of host countries institutions and enforceability of the law in developing countries. As a result, BITs guarantee them certain standards of treatments that can be enforced through investor state dispute settlement in international tribunals. Developing countries conclude BITs and accept restrictions on their sovereignty in the hope that the protection from political and other risks lead to increase in FDI flows. BITs aspire to protect, promote and in some instances to remove obstacles to foreign investment flows without looking at their implications on sustainable development. The purpose of this research is to examine the BITs framework in Tanzania, explores the increasing persuasiveness of these agreements in promoting FDIs and their impacts upon sustainable development. Sustainable development here refers to development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs. The thesis tries to look at what BITs say and identifies a number of key emerging development linkages and their implications on sustainable development. The thesis demonstrates that some BITs provisions have been seen to have disturbing and potentially worrying legal and policy implications for host states. Most BITs offer an avenue for dispute settlement mechanism that permits foreign investors to take host states to international arbitrations in cases where the investor alleges that the treaty’s provisions have been violated. As will be seen in this paper, the number of treaty based arbitrations has enormously increased in recent years. One of the main findings of the research is that, BITs are not mutually beneficial agreements and are one sided in favour of capital exporting countries. They are unbalance and can hardly provide the basis for a durable investment regime though they are reciprocal in appearance. Despite the fact that they establish equal rights and duties for both sides, capital flows from one side only. Thus, it is argued in this thesis that BITs lack clarity and consistency as benefits will accrue to the capital exporting countries. The thesis further argues that Tanzania faces some challenges regarding the provisions of BITs already concluded. Foreign investors are increasingly aware of the protection available under BITs, and increasingly inclined to invoke those rights in the face of undesirable government initiatives or proposals. The dissertation concludes that BITs will harbour important consequences for Tanzania and may have significant adverse implications if not well negotiated. It further reveals that BITs are not efficient in promoting sustainable development and there is a need for investment agreement to be balanced in a development dimension. Most of the treaties compare unfavourably with the model investment agreement drafted by the International Institute for Sustainable Development (IISD), and that the latter agreement provides a more development friendly template for such agreements. For that reason, Tanzania has to review its BITs so as to ensure that they are in harmony with the country’s broader social and economic principles for sustainable development. / Dissertation (LLM)--University of Pretoria, 2010. / Centre for Human Rights / unrestricted
|
48 |
Factors That Drive the Selection of Business Intelligence Tools in South African Financial Services ProvidersGina, Bonginkosi Phila 10 August 2021 (has links)
Innovation and technology advancements in information systems (IS) result in multiple product offerings and business intelligence (BI) software tools in the market to implement business intelligence systems (BIS). As a result, a high proportion of organisations fail to employ appropriate and suitable software tools meeting organisational needs, resulting in a prime number of BI solution failures and abandoned projects are therefore recorded. Due to such project failures, benefits associated with BI are not realised hence organisations loose enormous investments on BI solutions and competitive advantage. The study aims at discovering and exploring critical factors influencing the selection of BI tools when embarking on the selection process. This is a quantitative research study and questionnaire surveyed data was collected from 92 participants working in South African financial services providers listed on the Johannesburg Stock Exchange (JSE) appearing in the top 100 based on market capitalization. The data was analysed quantitative by employing the use of SPSS and SmartPLS-3 software's to test the significance of influential factors using the proposed conceptual model that emerged from the literature. The findings showed that a combination of domain technical and non-technical factors is critical. Therefore, software tool technical factors (functionality, ease of use, compatibility, availability of an integrated hardware/software package, and availability of source code), vendor technical factors (availability of technical support, technical skills, quality of product, availability of user manual for important information, tutorial for learning and troubleshooting guide, and experience in using product developed by the same vendor), and opinion non-technical factors (end-users, subordinates, outside personnel acquaintances, and improvement in customer service) emerged as significant combination of influential factors to be considered. The study contributes to both academia and industry by providing influential determinants for software tool selection. It is hoped that the findings presented will contribute to a greater understanding of factors influencing the selection of BI tools to researchers and practitioners alike. Furthermore, organisations seeking to select and deliver appropriate BI tools will be better equipped to drive such endeavours.
|
49 |
PCG in game bits and its effect on player behaviourJohansson, Gustav January 2020 (has links)
This dissertation presents a study that explores the idea of implementing PCG in game bits. Procedural Content Generation (PCG) refers to content in games that is created by an algorithm rather than a human. Game bits is the part of game content that relates to graphics, audio and other elements that don’t directly affect gameplay. The goal was to find out what a PCG implementation in game bits needs to affect player behaviour. Qualitative play sessions with interviews were performed to examine potential ways this could occur. Results show that no noticeable behavioural differences appeared due to PCG in game bits, but three properties are set up detailing how implementations would increase the odds of affecting player behaviour. These properties are: PCG implementation changing visuals drastically, different visual elements matching and game space generation matching game bits repeatedly.
|
50 |
CRC-kódy / CRC-codesLorenc, Filip January 2021 (has links)
This thesis deals with description of CRC codes, which is a type of polynomial error correction codes, and description of CAN and CAN FD protocols used in automobiles for data transmission between sensors. One of the security elements is usage of the CRC codes with the Hamming distance 6. Unfortunately, both protocols contain a design vulnerability which causes that some received messages with one wrong bit do not have to be detected by the protocol. The aim of the thesis was to describe this vulnerability and found out, if it was possible to eliminate it by using different CRC code. It managed to characterize all messages, which are not during this vulnerability detected by CRC code and based on that it was possible to prove, that the probability of error does not depend on a CRC code choice of a fixed length. 1
|
Page generated in 0.0411 seconds