Computing leakage current distributions and determination of minimum leakage vectors for combinational designsGulati, Kanupriya 16 August 2006 (has links)
Analyzing circuit leakage and minimizing leakage during the standby mode of oper- ation of a circuit are important problems faced during contemporary circuit design. Analysis of the leakage profiles of an implementation would enable a designer to select between several implementations in a leakage optimal way. Once such an im- plementation is selected, minimizing leakage during standby operation (by finding the minimum leakage state over all input vector states) allows further power reduc- tions. However, both these problems are NP-hard. Since leakage power is currently approaching about half the total circuit power, these two problems are of prime rel- evance. This thesis addresses these NP-hard problems. An Algebraic Decision Diagram (ADD) based approach to determine and implicitly represent the leakage value for all input vectors of a combinational circuit is presented. In its exact form, this technique can compute the leakage value of each input vector, by storing these leakage values implicitly in an ADD structure. To broaden the applicability of this technique, an approximate version of the algorithm is presented as well. The approximation is done by limiting the total number of discriminant nodes in any ADD. It is experimentally demonstrated that these approximate techniques produce results with quantifiable errors. In particular, it is shown that limiting the number of discriminants to a value between 12 and 16 is practical, allowing for good accuracy and lowered memory utilization. In addition, a heuristic approach to determine the input vector which minimizes leakage for a combinational design is presented. Approximate signal probabilities of internal nodes are used as a guide in finding the minimum leakage vector. Probabilistic heuristics are used to select the next gate to be processed, as well as to select the best state of the selected gate. A fast satisfiability solver is employed to ensure the consistency of the assignments that are made in this process. Experimental results indicate that this method has very low run-times, with excellent accuracy, compared to existing approaches.
12 May 2011
Sequential Equivalence checking has been and still is a challenging problem. Verifying two circuits that are structurally different but logically the same is very important and has many applications. Critical to the success of sequential equivalence checking is the determination of a sufficient portion of illegal states such that the two designs are equivalent outside of the illegal states. This work proposes a low-cost method to discover a subset of the illegal state space of a circuit by simulating and grouping some state variables to determine if any missing patterns are present. This thesis discusses the selection of simulated inputs, the grouping of flip-flops and what the missing patterns represent. Then all missing patterns are considered which are illegal state cubes and represent and compact them using BDDs. A BDD implementation was created to compact these illegal states more efficiently. Discussion is then done on the parameters of the BDD implementation design which can be used more efficiently given the situation. These illegal state cubes are considered to be implications which can be used to constrain a SAT solver. Results are then presented which show how effective these constraints are to proving equivalency using the SAT solver. Finally, the future work is discussed of discovering the illegal state space either faster or more completely. / Master of Science
Toulougoussou, Ange Barthélemy
19 December 2014
L'objectif de cette thèse est de développer une méthode de décomposition de domaine pour la résolution du système de Stokes discrétisé avec les éléments finis mixtes stables où la pression est continue comme Hood-Taylor et Mini. La nouvelle méthode résulte dela combinaison de FETI qui est appliquée à la vitesse et de BDD qui est appliquée à la pression sans découpler les inconnues. Elle hérite et découple les projecteurs grossiers associés à FETI et à BDD. La méthodologie débouche sur un système linéaire symétrique,semi-défini positif que nous avons résolu par la méthode du gradient conjugué projeté préconditionné. La méthode contient deux préconditionneurs grossiers creux et des préconditionneurs locaux exacts qui assurent son extensibilié, sa robustesse et son efficacité. L'introduction de projecteurs locaux construits à partir des modes de pression des sousdomaines étend la méthode aux éléments finis mixtes discontinues en pression et rend le problème grossier de BDD facultatif même en présence de la pression aux interfaces.Nous avons aisément appliqué la méthode à l'élasticité incompressible et quasi-incompressible et elle peut s'étendre de la même façon au cadre plus général des systèmes de point-selle issus des problèmes de minimisation sous contraintes grâce à sa nature algébrique. / The purpose of this thesis is to develop a domain decomposition method suitable tosolve the Stokes system discretized with stable mixte finite elements where pressure is continuous such as Hood-Taylor and Mini. The new method arises from the combinaison of FETI applied to the velocity and BDD applied to the pressure without decoupling the unknowns. It inherits and decouples the coarse projectors included in FETI and BDD. The methodology leads to a symmetric, positive semi-definite linear system that we solveby projected preconditioned conjugate gradient. The method contains two sparse coarse preconditionners and exact local preconditionners that ensure its scalability, its robustness and its efficiency. We use local projectors constructed from the constant pressure modes of the subdomains that enable an extension to mixte finite elements with discontinuous pressure and that make the coarse problem of BDD optional even in the presence of pressure on the interfaces. We have easily applied the method to incompressibleand almost incompressible elasticity and it can be extended the same way to other saddle-point systems arising from minimization problems under constraints due to its algebraic property.
Remoção eletroquímica dos inseticidas organofosforados metil paration e clorpirifós utilizando eletrodos de diamante dopado com boro / Electrochemical removal of organophosphates insecticides methyl parathion and clorpyrifos using boron-doped diamond electrodesSuellen Aparecida Alves 13 August 2014 (has links)
Os efluentes contendo agrotóxicos são a causa de grande preocupação uma vez que estes compostos apresentam toxicidade, persistência no meio ambiente e muitos são recalcitrantes. Dentre os compostos orgânicos utilizados no combate à pragas destacam-se os inseticidas organofosforados, os quais apresentam menor toxicidade quando comparados aos compostos organoclorados. Dois inseticidas organofosforados vêm sendo amplamente utilizados no Brasil, são eles: metil paration (MP) e clorpirifós (CP). Dentre os métodos de tratamento de efluentes, ressaltam-se os processos eletroquímicos com a utilização de eletrodo de diamante dopado com boro, que apresenta alta eficiência na remoção de compostos orgânicos com baixa capacidade de adsorção. Este estudo propõe um método de tratamento para efluente contendo MP e CP (em separado) utilizando eletrodos de diamante dopados com boro (DDB) com diferentes níveis de dopagem (15.000 e 30.000 ppm da relação B/C, designados de DDB15 e DDB30, respectivamente) em meio ácido. Os eletrodos foram caracterizados utilizando técnicas morfológicas e eletroquímicas, tais como Microscopia Eletrônica de Varredura, Microscopia Óptica Digital, Espectroscopia Raman, Difração de Raios X, Voltametria Cíclica e Microscopia Eletroquímica de Varredura. A eficiência no processo de degradação foi acompanhada por técnicas analíticas como espectroscopia na região do UV-Vis, Cromatografia Líquida de Alta Eficiência (CLAE) utilizando detectores de espectroscopia na região do UV e detector de arranjo de diodos (DAD) e analisador de carbono orgânico total (COT). A eficiência do processo foi relacionada com o nível de dopagem do eletrodo DDB bem como a natureza dos compostos. As imagens MEV mostraram o crescimento homogêneo dos filmes sobre o substrato titânio e os espectros Raman confirmam o crescimento do carbono com ligações sp3 (diamante) e a incorporação de átomos de boro. As análises de Difração de Raios X mostram a cristalinidade dos filmes DDB bem como a presença de impurezas. As caracterizações eletroquímicas mostram o amplo intervalo de potencial de ambos os eletrodos e a transferência eletrônica do sistema Fe(CN)63-/4- mostrou a maior reversibilidade com o eletrodo mais dopado. O mesmo comportamento foi obtido com a técnica de SECM. Os ensaios de degradação do inseticida MP mostraram que o eletrodo mais dopado foi mais eficiente na diminuição da concentração (valor máximo de 86%) e remoção da matéria orgânica (valor máximo de 72%) com menor consumo de energia elétrica. Em relação à remoção do inseticida CP, não foi observado diferença expressiva nas respostas de remoção do inseticida bem como na mineralização da matéria orgânica utilizando os dois eletrodos DDB. Entretanto, a cinética de remoção foi mais rápida quando utilizou-se o eletrodo DDB30. Deste modo, pode-se dizer que os eletrodos DDB altamente dopados são eficientes na remoção da matéria orgânica, mas a eficiência do aumento de dopagem deve ser associada ao composto a ser degradado. / Effluents containing pesticides are the cause of great concern because these compounds exhibit toxicity, environmental persistence and most are recalcitrant. Among the organic compounds used to combat pests highlight the organophosphate insecticides, which have lower toxicity when compared to organochlorine compounds. Two organophosphate insecticides have been widely used in Brazil, they are: methyl parathion (MP) and chlorpyrifos (CP). Among the methods of wastewater treatment, it emphasizes the electrochemical data with the use of boron-doped diamond electrode, which shows high efficiency in removing organic compounds with low adsorption capacity processes. This study proposes a method of treatment for wastewater containing MP and CP (separately) using electrodes of boron-doped diamond (BDD) with different doping levels (15,000 to 30,000 ppm B/C ratio, designated by BDD15 and BDD30, respectively) in acid medium. The electrodes were characterized using morphological and electrochemical techniques, such as Scanning Electron Microscopy, Digital Optical Microscopy, Raman Spectroscopy, X-Ray Diffraction, Cyclic Voltammetry and Scanning Electrochemical Microscopy. The efficiency of the degradation process was monitored by analytical techniques such as UV-Vis spectroscopy, High Performance Liquid Chromatography (HPLC) using spectroscopic detectors in the UV region and diode array detector (DAD) and the total organic carbon analyzer (COT). The process efficiency is related to the doping level of the BDD electrode and the compounds. The SEM images showed smooth growth of the film on the substrate titanium and the Raman spectra confirm the growth of carbon with sp3 bond (diamond) bonds and the incorporation of boron atoms. Analyses of X-Ray Diffraction showed the crystallinity of the BDD. Electrochemical characterizations showed the wide potential range of both electrodes and the electronic transfer system Fe(CN)63-/4- showed greater reversibility with more doped electrode. The same result was obtained with the SECM technique. MP insecticide assays showed that the most doped electrode was more effective in decreasing the concentration (maximum 86%) and removal of organic matter (maximum 72%) with lower electric consumption. Regarding the insecticide CP removal, no significant difference was observed in the pesticide removal and mineralization of organic matter using two BDD electrodes. However, the kinetics of removal was faster when the BDD30 electrode was used. Thus, it can be stated that highly doped electrodes are efficient in the organic matter removal, but the increase the efficiency of doping should be associated with the compound to be degraded.
Komaragiri, Vivek Chakravarthy
11 May 2002
Technology is improving at an amazing pace and one reason for this advancement is because of unprecedented growth in the field of Information Technology and also in Digital Integrated Circuit technology over the past few decades. The size of a typical modern database is in the order of high ends of gigabytes and even terabytes. Researchers were successful in designing complex databases but there is still lot of activity on effectively making use of this stored information. There have been significant advancements in the field of "Logic optimization" and also in "Information storage and retrieval" but there has been very little transfer of these methods. The purpose of this study is to investigate the use of powerful Computer Aided Design (CAD) techniques for efficient information storage and retrieval. In the work presented in this thesis, it is shown that Decision Diagrams can be used for efficient data storage and information retrieval. An efficient technique is proposed for each of the two key areas of research in Database systems known as "Query Optimization" and "Datamining". Encouraging results are obtained indicating that using hardware techniques for information processing can be a new approach for solving these problems. An SQL query is represented using a hardware data structure known as an AND/OR graph and an SQL parser is interfaced with AND/OR package to achieve query optimization. Optimization using AND/OR graphs works only in the Boolean domain and to make the process of query optimization more complete it has to be investigated in Multivalued domain. The possibility of using MDD as a data structure to represent the query in the multi valued domain is discussed and a synthesis technique is developed to synthesize Multi Valued Logic Networks using MDD. Another useful data structure known as BDD can be used to store the large transaction files used in datamining applications very effectively.
Ferrell, Emily Lauren
03 May 2019
No description available.
Weaver, Sean A.
No description available.
BARBOSA NETO, Alvaro Magnum
22 May 2015
Submitted by Fabio Sobreira Campos da Costa (firstname.lastname@example.org) on 2016-03-15T13:44:42Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTACAO_MESTRADO_ALVARO_MAGNUM_2015.pdf: 2738529 bytes, checksum: 1954d6163f8ba9074e68546e0f003f12 (MD5) / Made available in DSpace on 2016-03-15T13:44:42Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTACAO_MESTRADO_ALVARO_MAGNUM_2015.pdf: 2738529 bytes, checksum: 1954d6163f8ba9074e68546e0f003f12 (MD5) Previous issue date: 2015-05-22 / Criado por Dan North, o BDD (Behavior Driven Development) é uma técnica de desenvolvimento ágil de software baseada no TDD (Test Driven Development) e que foca no teste de software orientado por comportamentos, isto é, concentra-se nas razões pelo qual o software é criado e nos requisitos de comportamento do negócio. A utilização da técnica traz uma série de benefícios para projetos de desenvolvimento de software, contudo, ela não tem uma aceitação tão grande no mercado e é, muitas vezes, preterida em relação ao TDD. Esse trabalho faz uma análise dessa situação e também propõe um ambiente que visa facilitar a adoção do BDD através da análise dos seguintes questionamentos: quais características devem fazer parte de uma ferramenta para que ela facilite e dinamize a utilização do BDD no contexto de um projeto de desenvolvimento de software? Como permitir o uso da mesma por um cliente leigo em testes, e, ao mesmo tempo, agregar valor para o gerente do projeto, os testadores e os desenvolvedores de software? Como o cliente poderia acompanhar em tempo real se o que ele espera obter está, de fato, sendo construído? Como medir o impacto da ferramenta? Através de análises e resultados obtidos em mais de 12 anos de experiência profissional no setor de tecnologia de instituições públicas e privadas, além de pesquisas na literatura, entrevistas com profissionais de TI e avaliações de ferramentas BDD no mercado, foi concebido um plugin: o BDD Plugin for Mantis (BDDPM), uma ferramenta cujo objetivo é facilitar a adoção do BDD em projetos de desenvolvimento de software. Para avaliar o plugin quanto ao cumprimento dos objetivos, foi utilizada uma técnica denominada GQM (Goal/Question/Metric), que permite, através de objetivos bem estabelecidos, planejar e mensurar métricas de avaliação. O BDDPM foi avaliado com sucesso dentro de um ambiente de produção real, uma autarquia do Governo do Estado da Paraíba: a Paraíba Previdência. Este trabalho descreve, em detalhes, todo o ciclo de vida do projeto, desde sua concepção, passando por sua criação, tecnologias utilizadas, recursos incluídos, etc. / Created by Dan North, BDD (Behavior Driven Development) is a software agile development technique based on TDD (Test Driven Development). The BDD focuses on software testing oriented by behaviors, that is, it focuses on the reasons why a software is created and its business behavior. The use of the technique brings a number of benefits for software development projects; however, BDD does not have such a great market as the TDD: the first choice of the majority. This work brings an analysis of this situation and also proposes an environment to facilitate the adoption of BDD by examining the following questions: what characteristics should be part of a tool so that it facilitate and streamline the use of BDD in a context of project software development? How can it be used by an unexperienced client, and, at the same time, add value to project managers, testers and developers? How the customer could follow, in real time, if what he expects to, is really being built? How to measure the impact of the tool? Through analysis and results obtained from over 12 years of professional experience in the technology sector of public and private institutions, as well as research in the literature, interviews with IT professionals and reviews of BDD tools on the market, a plugin was developed: the BDD Plugin for Mantis (BDDPM), a tool which aims to facilitate the adoption of BDD in software development projects. To assess the plugin in meeting the goals, a technique called GQM (Goal / Question / Metric) was used; it allows, through well-established objectives, plan and measure evaluation metrics. The BDDPM was successfully evaluated in a real production environment, a company called Paraíba Previdência. This paper describes in detail the entire life cycle of the project: from its conception, through its creation, the technologies used, features included, etc.
Rajachidambaram, Sarojini Priyadarshini
01 January 2007
Kentucky Architecture nanocontrollers employ a bit-serial SIMD-parallel hardware design to execute MIMD control programs. A MIMD program is transformed into equivalent SIMD code by a process called Meta-State Conversion (MSC), which makes heavy use of enable masking to distinguish which code should be executed by each processing element. Both the bit-serial operations and the enable masking imposed on them are expressed in terms of if-then-else (ITE) operations implemented by a 1-of-2 multiplexor, greatly simplifying the hardware. However, it takes a lot of ITEs to implement even a small program fragment. Traditionally, bit-serial SIMD machines had been programmed by expanding a fixed bitserial pattern for each word-level operation. Instead, nanocontrollers can make use of the fact that ITEs are equivalent to the operations in Binary Decision Diagrams (BDDs), and can apply BDD analysis to optimize the ITEs. This thesis proposes and experimentally evaluates a number of techniques for minimizing the complexity of the BDDs, primarily by manipulating normalization ordering constraints. The best method found is a new approach in which a simple set of optimization transformations is followed by normalization using an ordering determined by a Genetic Algorithm (GA).
THE USE OF BORON-DOPED DIAMOND FILM ELECTRODES FOR THE OXIDATIVE DEGRADATION OF PERFLUOROOCTANE SULFONATE AND TRICHLOROETHYLENECarter, Kimberly Ellen January 2009 (has links)
The current treatment of water contaminated with organic compounds includes adsorption, air stripping, and advanced oxidation processes. These methods large quantities of water and require excessive energy and time. A novel treatment process of concentrating and then electrochemically oxidizing compound would be a more feasible practice. This research investigated the oxidative destruction of perfluorooctane sulfonate (PFOS), perfluorobutane sulfonate (PFBS) and trichloroethene (TCE) at boron-doped diamond film electrodes and the adsorption of PFOS and PFBS on granular activated carbon and ion exchange resins.Experiments measuring oxidation rates of PFOS and PFBS were performed over a range in current densities and temperatures using a rotating disk electrode (RDE) reactor and a parallel plate flow-through reactor. Oxidation of PFOS was rapid and yielded sulfate, fluoride, carbon dioxide and trace levels of trifluoroacetic acid. Oxidation of PFBS was slower than that of PFOS. A comparison of the experimentally measured apparent activation energy with those calculated using Density Functional Theory (DFT) studies indicated that the most likely rate-limiting step for PFOS and PFBS oxidation was direct electron transfer. The costs for treating PFOS and PFBS solutions were compared and showed that PFOS is cheaper to degrade than PFBS.Screening studies were performed to find a viable adsorbent or ion exchange resin for concentrating PFOS or PFBS. Granular activated carbon F400 (GAC-F400) and an ion exchange resin, Amberlite IRA-458, were the best methods for adsorbing PFOS. Ionic strength experiments showed that the solubility of the compounds affected the adsorption onto solid phases. Regeneration experiments were carried out to determine the best method of recovering these compounds from the adsorbents; however, the compounds could not be effectively removed from the adsorbents using standard techniques.The electrochemical oxidation of trichloroethene (TCE) at boron-doped diamond film electrodes was studied to determine if this would be a viable degradation method for chlorinated solvents. Flow-through experiments were performed and showed TCE oxidation to be very rapid. Comparing the data from the DFT studies and the experimentally calculated apparent activation energies the mechanism for TCE oxidation was determined to be controlled by both direct electron transfer and oxidation via hydroxyl radicals.
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