Cette dissertation montre que des applications embarquées complexes peuvent tirer partie efficacement de plateformes MP-SoC hétérogènes tout en respectant les critères de flexibilité, mise à l'échelle, portabilité et time-to-market. Elle fait la description d'un flot de conception de logiciel embarqué amélioré combinant un générateur de code, GECKO, et un environnement logiciel innovant, APES, afin d'obtenir un haut niveau d'efficacité. La contribution ainsi présentée est double : 1) un flot de conception de logiciel embarqué amélioré avec un ensemble d'outils permettant la construction automatique d'objets binaires minimaux pour une application donnée ciblant une plateforme MP-SoC donnée, et 2) un ensemble de composants logiciels modulaire et portable incluant des mécanismes de systèmes d'exploitations traditionnels ainsi que le support de multiples processeurs.

<p>This thesis reports case studies of students working with context rich problems (CRP) and mini projects (MP) in physics in an upper secondary school class and in a physics teacher education class at university. The students report a big shift from physics in secondary school as fun and easy, to physics in upper secondary school as boring, difficult and with lack of time for reflections and physics talking, but they also found physics as interesting in itself. In order to study how group discussions in physics influence the students learning and to study the phenomena of students’ ownership of learning (SOL) we introduced CRP and MP. We video recorded five groups with 14 teacher students at university in the end of 2002, and five group with 15 students at upper secondary school during the beginning of their second physics course in the spring term in 2003. MP and CRP in physics were used as instructional settings in order to give students possibility to strengthen their holistic understanding and their possibilities to ownership. When students get the opportunity to manage their own learning and studying by open-ended tasks in physics, without the teacher determining all details of the performance, this gives more ownership of learning. The advantage of MPs and CRPs from the student’s point of view is more freedom to act, think and discuss and from the teacher’s view, to get insights of the students’ ability and how they really think in physics. The ownership is found to be crucial for motivation and development of competence.</p><p><em>Students’ ownership of learning (SOL) is the students’ influence/impact to affect tasks and the learning environment in such a way that the students have a real opportunity to achieve learning of physics.</em></p><p>Students’ ownership of learning (SOL) is found at two levels:</p><p><strong>Group level:</strong> At the start of a task the SOL is determined by the design of the task. The choice of task, the performance (when, how, where), the level of result and presentatio n and report have to be determined by the students themselves.</p><p><strong>Individual level:</strong> A person’s experiences and anomalies of understanding have created unique questions that can create certain aspects of the task that drive this person to be very active and highly motivated. This gives the person a high individual ownership. We developed hypotheses concerning the relation between ownership, motivation and competence and we see some evidence in the cases reported in this thesis. The importance of exploratory talks to enhance learning, and to see aspects of communication as part of the motivation are discussed in the model of ownership, motivation and competence that is proposed.</p>

The conception of turbo codes by Berrou et al. has created a renewed interest in modern graph-based codes. Several encouraging results that have come to light since then have fortified the role these codes shall play as potential solutions for present and future communication problems. This work focuses on both practical and theoretical aspects of graph-based codes. The thesis can be broadly categorized into three parts. The first part of the thesis focuses on the design of practical graph-based codes of short lengths. While both low-density parity-check codes and rateless codes have been shown to be asymptotically optimal under the message-passing (MP) decoder, the performance of short-length codes from these families under MP decoding is starkly sub-optimal. This work first addresses the structural characterization of stopping sets to understand this sub-optimality. Using this characterization, a novel improved decoder that offers several orders of magnitude improvement in bit-error rates is introduced. Next, a novel scheme for the design of a good rate-compatible family of punctured codes is proposed. The second part of the thesis aims at establishing these codes as a good tool to develop reliable, energy-efficient and low-latency data dissemination schemes in networks. The problems of broadcasting in wireless multihop networks and that of unicast in delay-tolerant networks are investigated. In both cases, rateless coding is seen to offer an elegant means of achieving the goals of the chosen communication protocols. It was noticed that the ratelessness and the randomness in encoding process make this scheme specifically suited to such network applications. The final part of the thesis investigates an application of a specific class of codes called network codes to finite-buffer wired networks. This part of the work aims at establishing a framework for the theoretical study and understanding of finite-buffer networks. The proposed Markov chain-based method extends existing results to develop an iterative Markov chain-based technique for general acyclic wired networks. The framework not only estimates the capacity of such networks, but also provides a means to monitor network traffic and packet drop rates on various links of the network.

The ratio of auxin to cytokinin determines de novo organogenesis in plants. Relatively little is known about the effect of genetically altered auxin signaling on in vitro organogenesis. Here, callusogenesis, shoot, and root formation were studied in loss- (LOF) and gain-of-function (GOF) alleles in two phylogenetically related Auxin Response Factors (ARFs), MONOPTEROS (MP/ARF5) and NON-PHOTOTROPHIC HYPOCOTYL 4 (NPH4/ARF7). Reduced MP activity greatly diminished shoot regeneration, and partially diminished callusogenesis and root formation. LOF in NPH4 strongly decreased callusogenesis, and mildly decreased shoot and root regeneration in particular categories of explants. By contrast, organogenesis responses were strongly increased in aerial explants carrying the GOF transgene dMP. Thus, both MP and NPH4 seem to act as positive regulators of certain organogenesis processes and the GOF dMP transgene may be of interest for stimulating organogenesis in plant species with poor regeneration properties. Also, organogenesis in vitro may reveal unknown developmental ARF functions.

The ratio of auxin to cytokinin determines de novo organogenesis in plants. Relatively little is known about the effect of genetically altered auxin signaling on in vitro organogenesis. Here, callusogenesis, shoot, and root formation were studied in loss- (LOF) and gain-of-function (GOF) alleles in two phylogenetically related Auxin Response Factors (ARFs), MONOPTEROS (MP/ARF5) and NON-PHOTOTROPHIC HYPOCOTYL 4 (NPH4/ARF7). Reduced MP activity greatly diminished shoot regeneration, and partially diminished callusogenesis and root formation. LOF in NPH4 strongly decreased callusogenesis, and mildly decreased shoot and root regeneration in particular categories of explants. By contrast, organogenesis responses were strongly increased in aerial explants carrying the GOF transgene dMP. Thus, both MP and NPH4 seem to act as positive regulators of certain organogenesis processes and the GOF dMP transgene may be of interest for stimulating organogenesis in plant species with poor regeneration properties. Also, organogenesis in vitro may reveal unknown developmental ARF functions.

Submitted by PALOMA ANDRADE MARQUES (palomaamarques@yahoo.com.br) on 2015-10-27T16:33:41Z No. of bitstreams: 1 Dissertação_MFEE_-_Paloma Marques.pdf: 1152989 bytes, checksum: efcdcffc86187c1d459193dcdf27db60 (MD5) / Approved for entry into archive by GILSON ROCHA MIRANDA (gilson.miranda@fgv.br) on 2015-10-28T12:59:52Z (GMT) No. of bitstreams: 1 Dissertação_MFEE_-_Paloma Marques.pdf: 1152989 bytes, checksum: efcdcffc86187c1d459193dcdf27db60 (MD5) / Approved for entry into archive by Maria Almeida (maria.socorro@fgv.br) on 2015-10-30T12:25:21Z (GMT) No. of bitstreams: 1 Dissertação_MFEE_-_Paloma Marques.pdf: 1152989 bytes, checksum: efcdcffc86187c1d459193dcdf27db60 (MD5) / Made available in DSpace on 2015-10-30T12:26:45Z (GMT). No. of bitstreams: 1 Dissertação_MFEE_-_Paloma Marques.pdf: 1152989 bytes, checksum: efcdcffc86187c1d459193dcdf27db60 (MD5) Previous issue date: 2014-05-23 / The year 2012 was a milestone for the Brazilian electricity sector. It was a year of many surprises, debates and paradigm shifts. The sector was previously an example of stability and conservatism became the target of questions and criticism from different agents, investors, traders, consumers and governments. Regulatory basis of the brazilian electricity sector is very recent. However it is notable that there has been progress in recent decade, in favor of a better service to the population and the development of a good environment for investment. Both goals were followed by a greater concern about meeting energy demand, growing in the country, and low tariffs aiming no inflationary impacts. Despite this path, the issue of MP 579 in September 2012 led to an environment of uncertainty for new investments due to doubts about many rules sanctioned consequence of insufficient debate with the private sector. The MP had the ambition to reduce the electricity tariff paid by the final consumer, and used as the main mechanism to nonrenewal of concessions of power generation, a possibility provided in each plant concession contracts. This thesis analyzes the power generating sector in Brazil. Its energy matrix, framework of the regulatory model adopted, its evolution in recent decades, and motivation for the enactment of MP is studied. The main goal is to study its impact on investments in the sector. / O ano de 2012 foi um marco para o setor elétrico brasileiro. Foi um ano de muitas surpresas, debates e mudanças de paradigmas. Um setor tido anteriormente como exemplo de estabilidade e conservadorismo, passou a ser alvo de dúvidas e críticas por parte de diferentes agentes, investidores, operadores, consumidores e governantes. As bases regulatórias do setor elétrico brasileiro são muito recentes. Entretanto é notável que houve um progresso nas últimas décadas, em direção a um melhor serviço prestado à população e ao desenvolvimento de um ambiente propício ao investimento. Ambos os objetivos foram acompanhados de uma maior preocupação com o atendimento da demanda por energia, crescente no país, e com a busca por tarifas baixas de forma a não haver impactos inflacionários. Desviando desta trajetória, a edição da MP 579 em setembro de 2012 levou a um clima de insegurança para novos investimentos devido à falta de clareza a cerca de muitas regras sancionadas, consequencia do insuficiente debate com o setor privado. A MP teve como ambição diminuir a tarifa de energia paga pelo consumidor final, e usou como principal mecanismo a não renovação das concessões de geração de energia, possibilidade prevista nos contratos de concessão de cada usina de geração de energia. Esta tese faz uma análise do setor de geração energia do Brasil. Nela é estudada a matriz energética, aspectos do modelo regulatório adotado, sua evolução nas últimas décadas, e a motivação para a sanção da MP. O objetivo central é estudar seu impacto nos investimentos no setor.

Made available in DSpace on 2014-12-17T14:55:41Z (GMT). No. of bitstreams: 1 ViniciusSVS.pdf: 2441901 bytes, checksum: 1246fceb24d0749c8833cd005b384269 (MD5) Previous issue date: 2010-05-07 / The incorporate of industrial automation in the medical are requires mechanisms to safety and efficient establishment of communication between biomedical devices. One solution to this problem is the MP-HA (Multicycles Protocol to Hospital Automation) that down a segmented network by beds coordinated by an element called Service Provider. The goal of this work is to model this Service Provider and to do performance analysis of the activities executed by in establishment and maintenance of hospital networks / Com a incorpora??o de conceitos da automa??o industrial na ?rea m?dica, surge a necessidade de estabelecer mecanismos que permitam a comunica??o entre os dispositivos biom?dicos de maneira segura e eficiente. Dentre as solu??es para esse problema tem-se o PM-AH (Protocolo Multiciclos para Automa??o Hospitalar) que estabelece uma rede segmentada por leitos e coordenada por um elemento chamado Provedor de Servi?os. O objetivo desse trabalho ? modelar esse Provedor de Servi?os e efetuar an?lises de desempenho sobre as tarefas realizadas pelo mesmo no estabelecimento e manuten??o da rede hospitalar

Tributos implícitos refletem a extensão pela qual ativos favorecidos tributariamente têm seu retorno pré-imposto reduzido em comparação com o retorno pré-imposto de ativos sem benefício fiscal e de risco similar. Em condição de equilíbrio de mercado, se dois ativos de riscos semelhantes possuírem o mesmo fluxo de caixa pré-imposto, mas um deles for favoravelmente tributado em relação ao outro, haverá maior demanda pelo ativo menos tributado, que terá, portanto, seu preço relativo aumentado. Conseqüentemente, dado que o retorno pós-imposto é o mesmo para ambos, o retorno pré-imposto do ativo favorecido será menor que o retorno pré-imposto do ativo não-beneficiado. A perda de retorno pré-imposto sofrida pelo ativo beneficiado decorre da tributação implícita. O aumento de preço do ativo beneficiado pressupõe que haja um detentor disposto a vendê-lo um tipo de investidor para o qual a alteração nos preços relativos acontece sem que o seu retorno pós-imposto se altere: o investidor marginal. Investidores que possuam alíquota marginal de imposto explícita diferente da suportada pelo investidor marginal formam a denominada clientela tributária, que se constitui por um investidor para o qual a mudança nos preços relativos alteraria também o seu retorno pós-imposto. Os objetivos da tese são apresentar a teoria econômica e os conceitos subjacentes à tributação implícita, assim como comprová-la empiricamente. Trata-se de tema importante, pois traz à luz um tipo de tributação ainda pouco visível para a maioria dos indivíduos e das empresas, mas que é tão material quanto a explícita (descrita nos códigos e regulamentos tributários e provisionada nas demonstrações financeiras). A MP nº 281/2006, que introduziu a isenção de imposto de renda para os rendimentos produzidos por títulos públicos federais adquiridos por estrangeiros, foi o evento ao redor do qual se examinou o efeito causado pela isenção sobre os retornos da NTN-B, título escolhido pelos não-residentes à época do ato. A hipótese testada foi de que a entrada maciça do investidor estrangeiro reduziria significativamente o retorno pré-imposto do título. Para os testes, empregou-se a análise de séries temporais: o mesmo título foi utilizado antes (sem benefício fiscal) e depois (beneficiado quando adquirido por estrangeiros) da MP. Assim, a diferença de percepção de risco que investidores possuem ao carregar ativos diferentes ficou mitigada, o que permitiu que se isolasse o efeito do benefício tributário sobre os retornos. Os resultados confirmaram que o investidor estrangeiro sofreu uma significativa tributação implícita: a depender da série da NTN-B, o investidor estrangeiro foi tributado implicitamente de 11% a 13%. A pesquisa contém também uma outra situação relacionada à MP nº 281/2006, mas que decorreu de falta de liquidez da NTN-B, quando o estrangeiro quis sair do mercado em momento posterior à entrada em vigor da MP. Nesse segundo instante, comprovou-se que o investidor estrangeiro recebeu um tributo implícito pago pelo governo brasileiro. Procurou-se demonstrar que o tributo implícito não é tipicamente pago para as autoridades tributárias. Na entrada do estrangeiro, houve pagamento de tributo implícito do não-residente para o investidor nacional. No momento seguinte, quando o investidor estrangeiro desejou sair do papel, o governo pagou o imposto implícito recebido pelo não-residente. Esses resultados contribuem para a pesquisa tributária no Brasil ao trazer novos conceitos correlatos à tributação implícita e demonstrar empiricamente que alterações tributárias podem resultar em alteração no retorno pré-imposto de ativos. Por exemplo, decisões de investidores podem ser afetadas quando uma empresa que tradicionalmente pagava dividendos passa a distribuir o seu lucro na forma de juros sobre capital próprio, conforme prediz a teoria da clientela tributária. Os resultados e conceitos também podem auxiliar na análise das conseqüências, sobre a economia como um todo, da implantação de políticas tributárias, assim como na implementação específica de determinado incentivo tributário sobre o retorno pré-imposto dos mais variados tipos de ativo. / Implicit taxes reflect the extent to which tax-favored assets bear lower pre-tax returns than do tax-disfavored assets of similar risk. In equilibrium, when two assets give rise to identical pre-tax cash flows, but the cash flows from one asset are taxed more favorably than those from the other asset, the tax-favored asset will increase relative to the price of the taxdisfavored asset. Consequently, given that the after-tax returns are the same to both assets, the pre-tax rate of return to the tax-favored asset will fall below that for the tax-disfavored asset. The loss of pre-tax return bore by the tax-favored asset is due to the implicit tax. The price rise of the tax-favored asset indicates that there is an investor willing to sell it a kind of investor to whom the prices of the assets change, with the result that the after-tax rates of return will remain the same to them (the marginal investor). Investors with explicit tax rates different from the explicit tax rate faced by marginal investors form a group of investors known as tax clientele. Those investors (clientele) are not indifferent to assets differently taxed. This research aims to present the economic theory and the main concepts related to implicit taxes, and still to test empirically its existence. Implicit taxes are an important issue because it sheds light upon a kind of taxation practically invisible to most people and businesses, but yet as real as the explicit taxes. The Provisional Measure n. 281/2006, which provided income tax exemption to non-resident investors who acquired federal government bonds, was the event chosen to empirically test for implicit tax effects, by examining NTN-B return changes surrounding the act. Indications suggested that foreign investors focused on a long-term Brazilian bond called NTN-B. The hypothesis to be tested was that the massive entrance of foreign investors would significantly reduce the NTN-B pre-tax return. Time series analysis was employed: the same bond was used before (without the tax exemption) and after (with the tax exemption) the act. Therefore, this study is less subject to confounding cross-sectional risk differences, helping to distinguish between the effects of taxes and risk. Results of empirical tests report a significant decrease of return suffered by the foreign investor, from 11% to 13%, depending on the bond invested. The study also investigates another event related to the tax exemption, but actually connected to the small liquidity of the NTN-B. Few months later, the same foreign investor who massively bought the NTN-B in response to the tax exemption decided to leave the Brazilian market. At this time, the Brazilian government paid him a significant implicit tax. The comparison between the first event (tax exemption) and the second one (liquidity) shows that implicit taxes are typically not paid directly to the taxing authority. When the foreign investor first entered the market, he paid implicit taxes to the Brazilian investor. Later on, when the foreign investor decided to sell the bond recently bought, the Brazilian government then paid him implicit taxes. These results contribute to tax research by demonstrating that changes in tax rates may result in changes in pre-tax returns. For instance, according to the theory of tax clienteles, the decisions of investors might be affected when a Brazilian company decides to change its dividend policy, by paying interest on own equity instead of dividends. The results and concepts also provide information to tax policy makers on the economy-wide effects of tax rate changes, as well as the effects of specific tax incentives on pre-tax returns.

MHRD PhD scholarship / With Multiprocessor Systems-on-Chips (MPSoCs) pervading our lives, security issues are emerging as a serious problem and attacks against these systems are becoming more critical and sophisticated. We have designed and implemented different hardware based solutions to ensure security of an MPSoC. Security assisting modules can be implemented at different abstraction levels of an MPSoC design. We propose solutions both at circuit level and system level of abstractions. At the VLSI circuit level abstraction, we consider the problem of presence of noise voltage in input signal coming from outside world. This noise voltage disturbs the normal circuit operation inside a chip causing false logic reception. If the disturbance is caused intentionally the security of a chip may be compromised causing glitch/transient attack. We propose an input receiver with hysteresis characteristic that can work at voltage levels between 0.9V and 5V. The circuit can protect the MPSoC from glitch/transient attack. At the system level, we propose solutions targeting Network-on-Chip (NoC) as the on-chip communication medium. We survey the possible attack scenarios on present-day MPSoCs and investigate a new attack scenario, i.e., router attack targeted toward NoC enabled MPSoC. We propose different monitoring-based countermeasures against routing table-based router attack in an MPSoC having multiple Trusted Execution Environments (TEEs). Software attacks, the most common type of attacks, mainly exploit vulnerabilities like buffer overflow. This is possible if proper access control to memory is absent in the system. We propose four hardware based mechanisms to implement Role Based Access Control (RBAC) model in NoC based MPSoC.

Cette thèse s'inscrit dans un contexte où chaque saut technologique, voit apparaitre des circuits intégrés produits de plus en plus tôt dans la phase de qualification et où la technologie de ces circuits intégrés se rapproche de plus en plus des limitations physiques de la matière. Malgré des contre-mesures technologiques, on se retrouve devant un taux de défaillance grandissant ce qui crée des conditions favorables au retour des techniques de tolérance aux fautes sur les circuits intégrés non critiques.La densité d'intégration atteinte aujourd'hui nous permet de considérer les réseaux reconfigurables de processeur comme des architectures SoC d'avenir. En effet, l'homogénéité de ces architectures laisse entrevoir des reconfigurations possibles de la plateforme qui permettraient d'assurer une qualité de service et donc une fiabilité minimum en présence de défauts. Ainsi, de nouvelles solutions de protection doivent être proposées pour garantir le bon fonctionnement des circuits non plus uniquement au niveau de quelques sous-fonctionnalités critiques mais au niveau architecture système lui-même.En s'appuyant sur ces prérogatives, nous présentons une méthode de protection distribuée et dynamique innovatrice, D-Scale. La méthode consiste à détecter, isoler et recouvrir les systèmes en présence d'erreurs de type « crash ». La détection des erreurs qui ont pour conséquence un « crash » de la plateforme est basée sur un mécanisme de messages de diagnostique échangés entre les unités de traitement. La phase de recouvrement est quant à elle basée sur un mécanisme permettant la reconfiguration de la plateforme de manière autonome. Une implémentation de cette protection matérielle et logicielle est proposée. Le coût de protection est réduit afin d'être intégré dans de futures architectures multiprocesseurs. Finalement, un outil d'évaluation d'impacte des fautes sur la plateforme est aussi étudié afin de valider l'efficacité de la protection. / This thesis is placed in a context where, for each technology node, integrated circuits are design at an earlier stage in the qualification process and where the CMOS technology appears to be closer to the silicon physical limitations. Despite technological countermeasure, we face an increase in the failure rate which creates conditions in favor of the return of fault-tolerant techniques for non-critical integrated circuits.Nowadays, we have reached such an integration density that we can consider the reconfigurable processor array as future SoC architectures. Indeed, these homogenous architectures suggest possible platform reconfigurations that would ensure quality of service and consequently a minimum reliability in presence of defects. Thus, new protection solutions must be proposed to ensure circuit smooth operations not only for sub-critical functionalities but at the system architecture level itself.Based on these prerogatives, we present an innovative dynamical and distributed protection method, named D-Scale. This method consists in detecting, isolating and recovering the systems in the presence of error which lead to a "crash" of the platform. The crash error detection is based on heartbeat specific messages exchanged between PEs. The recovery phase is based on an autonomous mechanism which reconfigures the platform.A hardware/software implementation was proposed and evaluated. The protection cost is reduced in order to be integrated within future multi-processor SoC architectures. Finally, a fault effect analysis tool is studied in order to validate the fault-tolerant method robustness.