The unabated continuation of the Moore's law has allowed the doubling of the number of transistors per unit area of a silicon die every 2 years or so. At the same time, an increasing demand on consumer electronics and computing equipments to run sophisticated applications has led to an unprecedented complexity of hardware designs. These factors have necessitated the abstraction level of design-entry of hardware systems to be raised beyond the Register-Transfer-Level (RTL) to Electronic System Level (ESL). However, power envelope on the designs due to packaging and other thermal limitations, and the energy envelope due to battery life-time considerations have also created a need for power/energy efficient design. The confluence of these two technological issues has created an urgent need for solving two problems: (i) How do we enable a power-aware design flow with a design entry point at the Electronic System Level? (ii) How do we enable power aware High Level Synthesis to automatically synthesize RTL implementation from ESL? This dissertation distinguishes itself by addressing the following two issues: (i) Since power/energy consumption of electronic systems largely depends on implementation details, and high-level models abstract away from such details, power/energy estimation at such levels has not been addressed thoroughly. (ii) A lot of work has been done in applying various techniques on control-data-flow graphs (CDFG) to find power/area/latency pareto points during behavioral synthesis. However, high level C-based functional models of various compute-intensive components, which could be easily synthesized as co-processors, have many opportunities to reduce power. Some of these savings opportunities are traditional such as clock-gating, operand-isolation etc. The exploration of alternate granularities of these techniques with target applications in mind, opens the door for traditional power reduction opportunities at the high-level. This work therefore concentrates on the aforementioned two areas of inadequacy of hardware design methodologies. Our proposed solutions include utilizing ESL simulation traces and mapping those to lower abstraction levels for power estimation, derivation of statistical power models using regression based learning for power estimation at early design stages, etc. On the HLS front, techniques that insert the power saving features during the synthesis process using exploration of granularity and scope of clock-gating, sequential clock-gating are proposed. Finally, this work shows how to marry two domains, that is estimation and reduction. In this regard, a power model is proposed, which helps in predicting power savings obtained using clock-gating and further guiding HLS to selectively insert clock-gating. / Ph. D.

[pt] Nesta tese estudamos as propriedades físicas de materiais fortemente correlacionados e desordenados, usando Hamiltonianos modelos para descrevê-los. A tese está dividida em duas partes. Na primeira, estudamos o modelo de Anderson periódico para descrever as propriedades de um isolante Kondo. Em particular tomamos o composto de Ce3Bi4Pt3 como paradigma deste tipo de materiais caracterizados por apresentar um pequeno gap(da ordem dos meV ). Na presença de pequenas concentrações de impurezas metálicas como íons de La substituindo os de Ce, como é o caso da liga (Ce1-xLax)Bi4Pt3, sofre uma transição metal-isolante. O Hamiltoniano de Anderson periódico é resolvido a partir da solução de um único sítio atômico que logo é embebido numa rede de Bethe. Este modelo consegue explicar qualitativamente os resultados experimentais como a resistividade em função da temperatura para diferentes concentrações de íons de La, assim como as propriedades óticas do sistema puro. A influência da localização de Anderson nesta transição é analisada a partir do estudo da condutividade elétrica do sistema. A segunda parte está dedicada ao estudo das propriedades de sistemas descritos pelo Hamiltoniano de Falicov- Kimball, largamente utilizado para estudar fenômenos como a transição de valência e metal- isolante, também em compostos de Metais de Transição e Terras Raras. Neste modelo, o caráter destas transições ainda não está bem estabelecido já que o resultado é muito dependente da aproximação utilizada. Utilizamos o Hamiltoniano de Falicov-Kimball sem spin onde a banda de condução é tratada de forma exata já que mostramos a sua equivalência com o problema de uma liga. Os estados f são resolvidos em forma aproximada a partir da equação de movimento, aproximação que chamamos de Aproximação do Estreitamento Dinâmico(AED). Estudamos as propriedades eletrônicas como a ocupação dos estados localizados em função da energia local. Também neste caso, analisamos um sistema desordenado estudando o contraponto entre a correlação eletrônica e a desordem. As diferentes fases que aparecem no sistema como, metálica, isolante de Anderson e de Mott são investigadas em função dos parâmetros que definem o sistema. / [en] In this thesis we study the properties of strongly correlated and disordered materials, using model Hamiltonians to describe them. The thesis is divided in two parts. The first one studies the periodic Anderson model used to describe the properties of a Kondo insulator. In particular we take Ce3Bi4Pt3 as a paradigmatic compound, characterized by a small gap(of the order of meV ). For small concentration of metallic impurities, ions of La substituting Ce, the alloy (Ce1-xLax)Bi4Pt3 suffers a metal- insulator transition. The periodic Anderson Hamiltonian is solved using the atomic solution that is embedded into a Bethe lattice. This model explains the experimental results as the resistivity as a function of temperature for different concentrations of ions of La, as well as, the optical properties of the pure system. The Anderson localization is analyzed studying the electric conductivity of the system. The second part of the thesis is dedicated to study the property of a system described by the Falicov- Kimball Hamiltonian. This Hamiltonian has been used to study the valence and metal-insulator transitions in Transitions Metal and Rare Earth compounds. In this model, the character of these transitions is still not well understood, since it is very dependent of the approximation used. We study the Falicov-Kimball Hamiltonian without spin. The conduction band is exactly described since we show its equivalence with the problem of an alloy. The f states are studied using the equation of motion for the Green functions, decoupling them in a way defined as the Dynamic Narrowing Approximation(DNA). We study the occupation of the local states as a function of energy and other electronic properties. For an alloy the interplay between the electronic correlation and disorder is analized. The different phases that appear in the system, as metallic and Anderson and Mott insulating, are investigated as a function of the parameters that define the system.

[pt] Grande parte das indústrias e do comércio atacadista e varejista, depara-se com problemas referentes à estocagem de seus produtos em galpões. Visando otimizar as operações de armazenamento e recuperação destes produtos (livros, remédios, CDs, caixas, pallets etc) e melhorar a utilização dos espaços vagos, foi idealizado o desenvolvimento de um protótipo que busca funcionalidade operativa associada a baixo custo.O presente trabalho consiste na construção de um manipulador robótico, controlado através da porta paralela de um microcomputador e composto por guias lineares estruturais, fixadas a um módulo de armazenamento com escaninhos. Para a execução dos movimentos é utilizada a tecnologia de motores de passo, onde dois motores horizontais efetuam os movimentos na coordenada X e um motor vertical, na coordenada Y. Um mecanismo de garras, acionado por motoredutor, foi desenvolvido para a captação dos volumes padronizados (containers). Finalmente, um programa para gerenciamento dos movimentos também foi implementado, com o objetivo de minimizar as operações do manipulador. / [en] A great part of the industry and of the wholesaler and retailer commerce sector, is dealing with some problems related to the storage of their products in sheds. The development of this prototype was initiated in order to improve the products (books, medicines, CDs, boxes, pallets) storage / recovery operations and the use of the vacant spaces. This development also searched to satisfy functionality associated to the low cost. The presented work is based upon the construction of a robotic manipulator. It is controlled by the computer parallel port and composed by structural linear guides that are fixed on a storage module with small partitions, similar to drawers. The movement execution uses the technology of step motors. Two horizontal motors execute the coordinate X movements, and a vertical motor executes the coordinate Y movements. It was developed a end effector mechanism, activated by a motor reducer, in order to capture the standardized containers. It was also implemented a program for the movements management. It looks for the reduction of the manipulator operations. The document s finalization shows and comments the obtained results.

Sur les différents calculateurs du véhicule, de plus en plus d'organes sont commandés par un interrupteur en silicium (circuit MOSFET) au lieu d'un relais. En plus de la fonction de commutation de puissance, le MOSFET peut comprendre un dispositif de mesure du courant afin de contrôler le pilotage de l'organe et/ou assurer une fonction de diagnostic. On appelle ce type de composant un commutateur intelligent de puissance ou Smart Switch. Il est aussi prévu dans le Smart Switch un dispositif de coupure du courant, en cas d'échauffement interne dû à une surintensité électrique. Avec les dernières avancées technologiques, ces composants peuvent aussi intégrer de la logique de pilotage et une interface de liaison numérique avec un microprocesseur. Cette dernière caractéristique motive lesujet de l'étude afin de définir des lois de protection améliorées contre les échauffements dus à une surintensité électrique.En effet, d’un point de vue de la protection électrique, le MOSFET a été conçu pour obtenir les mêmes caractéristiques qu’un fusible, avec la possibilité supplémentaire d’être réenclenché comme un disjoncteur. Le but est d’étudier les lois de pilotage qui pourraient permettre de mieux suivre les limites thermiques d’un conducteur électrique, en particulier dans les faibles surintensités, de façon à pouvoir diminuer le diamètre (donc le coût) des fils tout en assurant une meilleure protection face aux courts circuits impédants (courts-circuits sur une résistance un peu inférieure à la résistance nominale ducircuit, dans un rapport entre 1 et 3 par exemple). / On various vehicles Electronic Control Unit (ECU), more and more members are controlled bya MOSFET circuits instead of a relay. In addition to the power switching function, the MOSFET maymeasure the current to the steering control of the body and / or to ensure that a diagnostic function. Wecall this type of component a smart power switch or Smart Switch. It is also provided in the SmartSwitch device power failure, if the internal heating caused by electrical current. With the latesttechnology, these components can also integrate control logic and an interface for connection to adigital microprocessor. This last characteristic motivates the subject of study in order to defineimproved protection laws against overheating caused by an electrical current.Indeed, from the point of view of electrical protection, the MOSFET has been designed toachieve the same characteristics as a fuse, with the additional possibility to be reset as a circuit breaker.The aim is to study the control laws that could lead to better monitor the thermal limits of an electricalconductor, especially in low current, so as to reduce the diameter (hence the cost) of son while ensuringbetter protection against short-circuit-impedance (short circuit resistance of a little less than thenominal resistance of the circuit, in a ratio between 1 and 3 for example).

We investigate into the limitations of the sum-product algorithm for binary low density parity check (LDPC) codes having isolated short cycles. Independence assumption among messages passed, assumed reasonable in all configurations of graphs, fails the most in graphical structures with short cycles. This research work is a step forward towards understanding the effect of short cycles on error floors of the sum-product algorithm. We propose a modified sum-product algorithm by considering the statistical dependency of the messages passed in a cycle of length 4. We also formulate a modified algorithm in the log domain which eliminates the numerical instability and precision issues associated with the probability domain. Simulation results show a signal to noise ratio (SNR) improvement for the modified sum-product algorithm compared to the original algorithm. This suggests that dependency among messages improves the decisions and successfully mitigates the effects of length-4 cycles in the Tanner graph. The improvement is significant at high SNR region, suggesting a possible cause to the error floor effects on such graphs. Using density evolution techniques, we analysed the modified decoding algorithm. The threshold computed for the modified algorithm is higher than the threshold computed for the sum-product algorithm, validating the observed simulation results. We also prove that the conditional entropy of a codeword given the estimate obtained using the modified algorithm is lower compared to using the original sum-product algorithm.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-04T22:06:03Z No. of bitstreams: 1 HELDER FERNANDO DE ARAÚJO OLIVEIRA - TESE PPGCC 2015..pdf: 1535968 bytes, checksum: ea0ac08d16d7773542f5d7193c85c162 (MD5) / Made available in DSpace on 2018-05-04T22:06:03Z (GMT). No. of bitstreams: 1 HELDER FERNANDO DE ARAÚJO OLIVEIRA - TESE PPGCC 2015..pdf: 1535968 bytes, checksum: ea0ac08d16d7773542f5d7193c85c162 (MD5) Previous issue date: 2015-11-10 / Capes / Consumo de energia é um grande desafio durante o projeto de um SoC (System-on-a-Chip). Dependendo do projeto, para garantir maior precisão na estimação do consumo de energia, pode ser necessário estimar o consumo de energia do sistema ou parte dele utilizando diferentes elementos: diferentes abordagens de estimação, ferramentas ou, até mesmo, modelos descritos em variadas linguagens e/ou níveis de abstração. Porém, consiste em um desafio incorporar tais elementos para criação de um ambiente de simulação distribuído e heterogêneo, o qual permita que estes se comuniquem e troquem informações de modo sincronizado. Diante do exposto, a presente pesquisa tem como objetivo desenvolver uma abordagem, utilizando-se High Level Architecture (HLA), a fim de permitir a criação de um ambiente de simulação distribuído e heterogêneo, composto por diferentes ferramentas e modelos. Estes modelos podem ser descritos em diversas linguagens e/ou níveis de abstração, como também podem utilizar diferentes abordagens a estimação do consumo de energia. O uso da HLA permite que os elementos que compõem este ambiente heterogêneo possam ser simulados de maneira sincronizada e distribuída. A abordagem deve proporcionar a coleta e o agrupamento de dados de estimação de consumo de energia de modo centralizado. Para realização dos estudos de caso, foi utilizado um benchmark composto por um conjunto escalável de MPSoC (MultiProcessor System-on-Chip) descrito em C++/SystemC e o arcabouço Ptolemy. Um projeto em SystemVerilog/Verilog também foi utilizado para validar a coleta de dados de estimação de consumo de energia de modelos descritos nessas linguagens, por meio da abordagem proposta. Resultados experimentais demonstraram a flexibilidade da abordagem e sua aplicabilidade para a criação de um ambiente de simulação síncrono e heterogêneo, o qual promove uma visão integrada dos dados de energia estimados. / Energy consumption is a big challenge in SoC (System-on-a-Chip) design. Depending on the project requirements, to guarantee a better accuracy in power estimation, it might be necessary to estimate the power consumption of a system or part of it using different elements: different power estimation approaches, tools or, even, models described in different languages and/or abstraction levels. However, it is a challenge to incorporate these elements to create a simulation environment distributed and heterogeneous, which allows these elements to communicate and exchange information synchronously. In view of what has been exposed, the present research aims to develop an approach using HLA (High Level Architecture), enabling the creation of an environment distributed and heterogeneous, composed by different tools and models. These models can be described in different languages and/or abstraction levels, as well as use different power estimation approaches. The use of HLA enables the synchronized and distributed simulation of the elements that compose the simulation environment. The approach must allow the collecting and grouping of power estimation data in a centralized manner. As a case study, it has been used a benchmark composed of a scalable set of MPSoCs (MultiProcessor Systemon-Chip) which is described in C++/SystemC and the Ptolemy framework. A project in SystemVerilog/Verilog was also used to validate the power estimation data collected from models described in these languages, through the proposed approach. The experimental results show the approach flexibility and its applicability on creation of a distributed and synchronous simulation environment, which promotes an integrated view of power estimation data.

Le développement des systèmes multiprocesseurs intégrés sur puce (MPSoC) répond au besoin grandissant des architectures de calcul intensif. En revanche, l'évolution de leurs performances est entravée par leurs réseaux de communication sur puce (NoC) à cause de leur consommation d'énergie ainsi que du retard. C'est dans ce contexte que les NoC à base d'interconnexions RF et filaires (RFNoC) ont émergé. Afin de gérer au mieux et d'optimiser la conception d'un RFNoC, il est indispensable de développer une plateforme de simulation intégrant à la fois des circuits analogiques et numériques.Dans un premier temps, la simulation temporelle d'un RFNoC avec des composants dont les modèles sont idéaux est utilisée pour optimiser l'allocation des ressources spectrales disponibles. Le cas échéant, nous proposons des solutions pour améliorer la qualité de signal transmis. Dans un deuxième temps, nous avons développé en VHDL-AMS des modèles comportementaux et précis de chacun des composants du RFNoC. Les modèles de l'amplificateur faible bruit (LNA) et du mélangeur, prennent en compte les paramètres concernant, l'amplification, les non-linéarités, le bruit et la bande passante. Le modèle de l'oscillateur local considère les paramètresconventionnels, notamment le bruit de phase. Quant à la ligne de transmission, un modèle fréquentiel précis, incluant l'effet de peau est adapté pour les simulations temporelles. Ensuite, l'impact des paramètres des composants sur les performances du RFNoC est évalué afin d'anticiper les contraintes qui s'imposeront lors de la conception du RFNoC. / The development of multiprocessor systems integrated on chip (MPSoC) respondsto the growing need for intensive computation systems. However, the evolutionof their performances is hampered by their communication networks on chip(NoC) due to their energy consumption and delay. It is in this context that the wired RF network on chip (RFNoC) was emerged. In order to better manage and optimize the design of an RFNoC, it is necessary to develop a simulation platform adressing both analog and digital circuits.First, a time domaine simulation of an RFNoC with components whose modelsare ideal is used to optimize the allocation of the available spectrum resources. Where appropriate, we provide solutions to improve the quality of transmitted signal. Secondly, we have developed, in VHDL-AMS, behavioral and accurate models of all RFNoC components. The models of the low noise amplifier (LNA) and the mixer take into account the parameters for the amplification, nonlinearities, noise and bandwidth. The model of the local oscillator considers the conventional parameters, including its phase noise. Concerning the transmission line, an accurate frequency model, including the skin effect is adapted for time domaine simulations. Then, the impact of component parameters on RFNoC performances is evaluatedto anticipate constraints of the RFNoC design.

<p>U ovoj doktorskoj disertaciji je razvijen elektronski senzorski sistem za merenje deformacija pri savijanju pomoću polimernog optičkog vlakna sa osetljivom zonom. Opisana je metoda izrade fiber-optičkog senzora zakrivljenosti pomoću polimernog optičkog vlakna. Izvršena je simulacija ponašanja senzora i urađena je karakterizacija senzora. Ispitana je mogućnost primene elektronskog senzorskog sistema za detekciju savijanja i loma građevinskih struktura. Pomoću istog senzora je realizovan fiber-optički goniometar za merenje ugla savijanja ljudskog kolena koji karakterišu linearni odziv u opsegu uglova od -45&deg; do 25&deg;, rezolucija od 1&deg; i osetljivost od 20 mV/&deg;. U tezi je takođe data metoda eliminacije grešaka koje mogu nastati usled savijanja delova vlakna koji vode do i od osetljive zone.</p> / <p>In this thesis, an electronic system for measurement of bend-induced<br />deformations by using polymer optical fiber with sensitive zone is developed.<br />A method for fabrication of the fiber-optic curvature sensor by using polymer<br />optical fiber is described. The simulation and characterization of the sensor<br />behavior have been conducted. The possibility of application of the proposed<br />electronic system in structural health monitoring for bending and crack<br />detection of civil engineering structures is investigated. Also, a fiber-optic<br />goniometer for human joint movement monitoring characterized by a linear<br />response in the range from -45&deg; to 25&deg;, resolution of 1&deg;, and the sensitivity of<br />20 mV/&deg; is implemented. A method for the elimination of errors which may be<br />caused due to bending of lead-in and lead-out sections of the fiber (leading<br />to and from the sensitive zone) is also described.</p>

Bibliography: pages 184-207 / Digital records are either stored in an enterprise resource planning (ERP) system or electronic content management (ECM), or managed without the benefit of either system. In many countries, public and private organisations have implemented ECM systems, some have implemented ERP systems and others generate digital records without the benefit of any controlled system. In most organisations such systems are not integrated resulting in duplication and fragmentation of records. The South African Water Utility company, Rand Water, has implemented both ERP and ECM systems. Investing in these systems as an organisation comes at a cost but it can add value when used optimally to improve the organisation’s productivity and efficiency. To achieve high productivity and efficiency, integration of an ERP system into an ECM system is a requirement but remains lacking. This qualitative study utilised the Actor Network Theory to explore the integration of ERP into ECM at the South African Water Utility company, Rand Water, with a view to developing a framework for integration of the systems. The study utilised a system analysis case design with fourteen interviews conducted at different levels in the organisation and diverse business units using ERP and ECM to perform their operational deliverables in line with the organisation’s business objectives. The interviews were augmented with data from document analysis of policies, specifications and functionalities of the systems to determine the feasibility of integration. The study established that the water utility company has implemented ERP systems (SAP) since 1994 and ECM system since 1991 (Papertrail and later IBM FileNet) with only information flow module integrated. The study suggested that to integrate ERP into ECM, human and non-human actors need to collaborate to ensure that the actor network being integrated is achieved. The study also presents a strategy discussion for integrating ERP into ECM. A further study on the transfer of digital records in ECM into archival custody is recommended. / Information Science / D. Phil. (Information Science)