BARBOSA, G. S. Ensaios sobre preços dos produtos agrícolas no Brasil. 2017. 102 f. Dissertação (Mestrado em Economia Rural) - Centro de Ciências Agrárias, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Carlene Miranda (carlenematias@hotmail.com) on 2017-10-24T17:34:38Z No. of bitstreams: 1 2017_dis_gsbarbosa.pdf: 1787216 bytes, checksum: 4cfba4d364dbf8c66ff263e1c6cb2d92 (MD5) / Approved for entry into archive by Margareth Mesquita (margaret@ufc.br) on 2017-10-25T19:28:42Z (GMT) No. of bitstreams: 1 2017_dis_gsbarbosa.pdf: 1787216 bytes, checksum: 4cfba4d364dbf8c66ff263e1c6cb2d92 (MD5) / Made available in DSpace on 2017-10-25T19:28:42Z (GMT). No. of bitstreams: 1 2017_dis_gsbarbosa.pdf: 1787216 bytes, checksum: 4cfba4d364dbf8c66ff263e1c6cb2d92 (MD5) Previous issue date: 2017 / CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO (CNPq) / This dissertation consists of three chapters. However, the results obtained with the same data source, in order to analyze a convergence of wholesale prices of vegetables without distribution market. They use 37 horticultural products for 16 markets, covering the period from January 2007 to July 2015, with series of 103 observations. The first chapter comprises a linear approach, a unit root assay test for the balance sheet data and the estimation and the convergence, adopted in the studies of Dobado and Marrero (2005); Dreger et al. (2007); Wolszczak-Derlacz (2008) and Lindenblatt and Feuerstein (2015). The results indicate the validity of the Law of One Price for convergence in all products, since convergence violates this hypothesis for 33 products. (2008) and adapted to the Brazilian horticultural sector by Tabosa, Ferreira and Castelar (2008) and adaptation to the Brazilian horticultural sector by Tabosa, Ferreira and Castelar (2014), which tested a convergence of wholesale price markets. Therefore, the process of determining the Law of One Price (LPU), it is said that the convergence of prices occurs in the various markets analyzed, implying that prices converge to a certain steady state, ie a long-term equilibrium price. The tests do not reject the hypothesis that the model was estimated linear (Evans-Karras model). The results point to markets that are not subject to time limits, however, conditioned to transaction costs. In the last chapter, a database provided by Agrolink, which presented price quotations for the states of Mato Grosso, Brazil, Paraná and Rio Grande do Sul, with no period from March 2004 to November 2016, for a total of 152 Observations. Using a methodology developed by Vahid and Engle (1993), using the Beveridge-Nelson-Stock-Watson multivariate decomposition approach (BNSW). The decomposition test the presence of common long-term and short-term dynamics, with the Vector Autoregressive (VAR) estimation. The results indicate only a common trend for soybean-producing states, which suggests a convergence of long-term product prices. In the short term, the two cycles common among the states, which insinuate the difference in the crops of the markets. Mato Grosso stands out as a reference state, there is a strong positive correlation with the common cycle 1, while Paraná and Rio Grande do Sul have a negative correlation with this cycle, suggesting that there is a capital transition to the state of Mato Grosso. / Esta dissertação é constituída por três capítulos. Todavia, ressalta-se que dois capítulos utilizam a mesma fonte de dados, com o intuito de analisar a convergência de preços atacadistas dos produtos hortifrutigranjeiros no mercado de distribuição. Estes usam em sua investigação 37 produtos hortifrutigranjeiros para 16 mercados, entre jan./2007 a jul./2015, com séries de 103 observações. O primeiro capítulo compreende uma abordagem linear, na qual se realizaram os testes de raízes unitárias para dados em painel estimando-se β e σ convergência, adotado nos estudos de Dobado e Marrero (2005); Dreger et al. (2007), Wolszczak-Derlacz (2008) e Lindenblatt e Feuerstein (2015). Os resultados indicaram validade da Lei do Preço Único (LPU) para o β-convergência em todos os produtos, enquanto o σ-convergência viola essa hipótese para 33 produtos. O segundo capítulo explanou acerca dos métodos para testes de raízes unitárias com Threshold Autorregressivos (TAR) para dados em painel, com ênfase na técnica econométrica elaborada por Beyaert e Camacho (2008) e adaptada para o setor hortifrúti brasileiro por Tabosa, Ferreira e Castelar (2014), que testaram a convergência do tomate nos mercados de preços atacadistas. Diante disso, caso constatada a Lei do Preço Único, diz-se que ocorre convergência dos preços nos diversos mercados analisados, insinuando que os preços convergem para um dado estado estacionário, ou seja, um preço de equilíbrio de longo prazo. Os primeiros testes não rejeitam a hipótese nula de que o modelo a ser estimado seja linear (modelo Evans-Karras). Os resultados apontaram para mercados que convergem no longo prazo, todavia, condicionados aos custos de transação, que podem ser ocasionados pela ineficiência da logística de transportes, legislação dos estados, logística do setor, cambio de informações, subsídios do governo e perecibilidade dos produtos. No último capítulo, a base de dados utilizada foi do Agrolink, que apresenta cotações de preços da soja para os estados do Mato Grosso, Paraná e Rio Grande do Sul, entre mar./2004 e nov./2016, perfazendo um total de 152 observações. Foi utilizada a metodologia desenvolvida por Vahid e Engle (1993), por meio da abordagem de decomposição multivariada de Beveridge-Nelson-Stock-Watson (BNSW). A decomposição testou a presença de dinâmicas comuns de longo e curto prazo, com estimação do Vetor Autorregressivo (VAR). Os resultados indicaram apenas uma tendência comum para os estados produtores de soja, que sugere uma convergência dos preços desses produtos no longo prazo. No curto prazo, foram encontrados dois ciclos comuns entre os estados, o que insinua diferença nas safras desses mercados. O Mato Grosso destaca-se como estado benchmark, pois tem correlação positiva forte com o ciclo comum 1, enquanto o Paraná e o Rio Grande do Sul apresentam correlação negativa com esse ciclo, sugerindo que há uma transição de capital destes para o estado do Mato Grosso.

Circuitos baseados em portas lógicas de limiar (threshold logic gates – TLG) vem sendo estudados como uma alternativa promissora em relação ao tradicional estilo lógico CMOS, baseado no operadores AND e OR, na construção de circuitos integrados digitais. TLGs são capazes de implementar funções Booleanas mais complexas em uma única porta lógica. Diversos novos dispositivos, candidatos a substituir o transistor MOS, não se comportam como chaves lógicas e são intrinsicamente mais adequados à implementação de TLGs. Exemplos desses dispositivos são os memristores, spintronica, diodos de tunelamento ressonante (RTD), autômatos celulares quânticos (QCA) e dispositivos de tunelamento de elétron único (SET). Para o desenvolvimento de um fluxo de projeto de circuitos integrados baseados em lógica threshold, duas etapas são fundamentais: (1) identificar se uma dada função Booleana corresponde a uma função lógica threshold (TLF), isto é, pode ser implementada em um único TLG e computar os pesos desse TLG; (2) se uma função não é identificada como TLF, outro método de síntese lógica deve construir uma rede de TLGs otimizada que implemente a função. Este trabalho propõe métodos para atacar cada um desses dois problemas, e os resultados superam os métodos do estado-da-arte. O método proposto para realizar a identificação de TLFs é o primeiro método heurístico capaz de identificar todas as funções de cinco e seis variáveis, além de identificar mais funções que os demais métodos existentes quando o número de variáveis aumenta. O método de síntese de redes de TLGs é capaz de sintetizar circuitos reduzindo o número de portas TLG utilizadas, bem como a profundidade lógica e o número de interconexões. Essa redução é demonstrada através da síntese dos circuitos de avaliação da MCNC em comparação com os métodos já propostos na literatura. Tais resultados devem impactar diretamente na área e desempenho do circuito. / In this work, a novel method to synthesize digital integrated circuits (ICs) based on threshold logic gates (TLG) is proposed. Synthesis considering TLGs is quite relevant, since threshold logic has been revisited as a promising alternative to conventional CMOS IC design due to its suitability to emerging technologies, such as resonant tunneling diodes, memristors and spintronics devices. Identification and synthesis of threshold logic functions (TLF) are fundamental steps for the development of an IC design flow based on threshold logic. The first contribution is a heuristic algorithm to identify if a function can be implemented as a single TLG. Furthermore, if a function is not detected as a TLF, the method uses the functional composition approach to generate an optimized TLG network that implements the target function. The identification method is able to assign optimal variable weights and optimal threshold value to implement the function. It is the first heuristic algorithm that is not based on integer linear programming (ILP) that is able to identify all threshold functions with up to six variables. Moreover, it also identifies more functions than other related heuristic methods when the number of variables is more than six. Differently from ILP based approaches, the proposed algorithm is scalable. The average execution time is less than 1 ms per function. The second major contribution is the constructive process applied to generate optimized TLG networks taking into account multiple goals and design costs, like gate count, logic depth and number of interconnections. Experiments carried out over MCNC benchmark circuits show an average gate count reduction of 32%, reaching up to 54% of reduction in some cases, when compared to related approaches.

Introdução: Embora a relação entre privação de sono e limiar de dor tenha sido estudada em condições patológicas de quadros álgicos agudos e crônicos, os mecanismos envolvidos neste processo ainda carecem de investigações. Nesse contexto, sabe-se que são crescentes as situações nas quais a restrição de sono aguda é induzida por atividades laborais cotidianas, e a compreensão desta relação demanda modelos que permitam observar o efeito em condições em que os estímulos sejam padronizados e controlados. Assim sendo, investigamos o efeito da restrição aguda de sono na função autonômica e sua relação com limiares de dor em indivíduos saudáveis. Objetivos: Avaliar a relação entre respostas autonômicas e percepção a estímulos nociceptivos térmicos e elétricos pós-restrição aguda de sono ocasionada por estresse laboral. Métodos: Foram avaliados 19 estudantes de Medicina saudáveis após noite de sono habitual (SN) e após plantão noturno de 12 horas (RS). Primeiramente examinamos características clínicas dos sujeitos utilizando escalas para avaliação de sono e sintomas psiquiátricos. Foram realizados também testes quantitativos de sensibilidade para sensações térmicas e elétricas e registradas respostas cutâneas simpáticas (RCS) induzidas por estímulo elétrico duplo com diferentes intervalos interestímulos (ISI). Resultados: A média de duração do sono durante as 12 horas de plantão noturno foi de 120+ 28 minutos. Os escores de ansiedade foram maiores na fase RS quando comparados com os da fase SN (p<0,01). Após restrição de sono, houve diminuição no limiar de dor, mas não nos limiares de calor e elétricos. Em relação às respostas autonômicas, foram evidenciadas maiores amplitudes da RCS bem como aumento do número de duplas respostas em ISI 2s na fase RS. Também foi observada moderada correlação inversa entre limiares de dor e amplitudes da RCS (r= -0,45; p<0,01). Não foi encontrada correlação entre escores de ansiedade e parâmetros RCS. No entanto, no modelo de regressão linear multivariada, a percepção do limiar de dor ao estímulo térmico foi significativamente correlacionada com a amplitude da resposta cutânea simpática (β = - 0.55; 95% CI, -0.65 to -0.07), mas não com escores de ansiedade (p>0.05). Conclusões: Os efeitos da restrição aguda de sono no limar de dor são específicos e parecem não estar relacionados com alterações na percepção sensorial geral. Hiperalgesia foi associada com respostas autonômicas anormais, mas não com aumento da ansiedade, sugerindo a existência de uma associação entre o sistema nociceptivo e o autonômico, independente do estado emocional. / Background: Although the relationship between sleep deprivation and pain threshold has been studied in pathological acute and chronic conditions, the mechanisms involved in this process still require investigation. In this context, it is known that there is an increasing of situations where acute sleep restriction is induced by daily working activities and to understand this relationship is necessary models that allow the observation of the effect in situations in which the stimuli are standardized and controlled. Therefore, we investigated the effect of the acute sleep restriction on autonomic function and its relation with pain thresholds in healthy subjects. Objectives: Evaluating the relationship between autonomic responses and perception of thermal and electrical nociceptive stimuli after acute sleep restriction caused by stressful work. Methods: We evaluated 19 healthy medical students after normal night of sleep (NS) and after 12-hour night shift (SR). First we examined clinical characteristics of the subjects using scales for assessment of sleep and psychiatric symptoms. Also, we performed quantitative tests of sensitivity to thermal and electrical sensations and recorded double-electric-induced sudomotor skin responses (SSR) at different inter-stimulus intervals (ISI). Results: The total mean duration of sleep was 120 ± 28 minutes out of 12 hours of night shift. The anxiety scores were higher in SR Phase in comparison with those from NS Phase (p<0.01). After SR, there was a decrease in heat pain, but not in warm neither electrical threshold. Regarding autonomic responses, SR subjects showed higher SSR amplitudes and increased number of double responses at ISI 2s. It was also observed a moderate inverse correlation between heat pain thresholds and SSR amplitude (r = -0.45; P<0.01). However, there was no correlation between anxiety scores and SSR parameters. Indeed, in the multivariate linear regression model, heat pain perception was significantly correlated with SSR amplitudes (β = - 0.55; 95% CI, -0.65 to -0.07), but not with anxiety scores (p>0.05). Conclusions: The effects of SR on pain are specific and seem to be not related to general changes in sensory perception. Hyperalgesia was associated with abnormal autonomic responses, but not with increased anxiety, suggesting an association between the nociceptive and autonomic systems, independent of the emotional state.

Online social networks (OSNs) have become a powerful medium of communicating, sharing and disseminating information. Because of popularity and availability of OSNs throughout the world, the connected users can spread information faster and thus propagate influence over each other constantly. Due to such impact, a lot of applications on OSNs focused on picking an initial set of users (seeds) to infuse their message in the OSN. Due to huge size of the network, the main challenge in picking the initial set is to maximize the resultant influence over the users in the network. The optimization problem of finding out the most influential set of members in an OSN for maximization of influence is an NP-hard problem. In this paper, we propose using the Positive Influential Dominating Set (PIDS) algorithm for the initial seed. PIDS is a well-known algorithm which determines the influential backbone nodes in the networks. We implemented PIDS-based influence maximization by using different propagation models. We compared PIDS performance to that of the existing approaches based on greedy and random heuristics. The experimental results from extensive simulation on real-world network data sets show that PIDS gives better influence spread than greedy and random for both Independent Cascade Model and Linear Threshold Model of influence propagation. PIDS is also scalable to large networks and in all size ranges, it performs well in influence maximization.

The memristor is an emerging nano-device. Low power operation, high density, scalability, non-volatility, and compatibility with CMOS Technology have made it a promising technology for memory, Boolean implementation, computing, and logic systems. This dissertation focuses on testing and design of such applications. In particular, we investigate on testing of memristor-based memories, design of memristive implementation of Boolean functions, and reliability and design of neuromorphic computing such as neural network. In addition, we show how to modify threshold logic gates to implement more functions. Although memristor is a promising emerging technology but is prone to defects due to uncertainties in nanoscale fabrication. Fast March tests are proposed in Chapter 2 that benefit from fast write operations. The test application time is reduced significantly while simultaneously reducing the average test energy per cell. Experimental evaluation in 45 nm technology show a speed-up of approximately 70% with a decrease in energy by approximately 40%. DfT schemes are proposed to implement the new test methods. In Chapter 3, an Integer Linear Programming based framework to identify current-mode threshold logic functions is presented. It is shown that threshold logic functions can be implemented in CMOS-based current mode logic with reduced transistor count when the input weights are not restricted to be integers. Experimental results show that many more functions can be implemented with predetermined hardware overhead, and the hardware requirement of a large percentage of existing threshold functions is reduced when comparing to the traditional CMOS-based threshold logic implementation. In Chapter 4, a new method to implement threshold logic functions using memristors is presented. This method benefits from the high range of memristor’s resistivity which is used to define different weight values, and reduces significantly the transistor count. The proposed approach implements many more functions as threshold logic gates when comparing to existing implementations. Experimental results in 45 nm technology show that the proposed memristive approach implements threshold logic gates with less area and power consumption. Finally, Chapter 5 focuses on current-based designs for neural networks. CMOS aging impacts the total synaptic current and this impacts the accuracy. Chapter 5 introduces an enhanced memristive crossbar array (MCA) based analog neural network architecture to improve reliability due to the aging effect. A built-in current-based calibration circuit is introduced to restore the total synaptic current. The calibration circuit is a current sensor that receives the ideal reference current for non-aged column and restores the reduced sensed current at each column to the ideal value. Experimental results show that the proposed approach restores the currents with less than 1% precision, and the area overhead is negligible.

xiii, 160 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Feldstein and Horioka (1980) motivated the international finance literature by claiming a least squares regression of domestic investment rates on domestic savings rates is an informative measure of capital mobility. Their method stirred up controversy when they interpreted a high correlation between savings and investment rates as evidence of capital immobility, creating the famous Feldstein-Horioka puzzle. Current research starts with the Feldstein-Horioka result and shifts focus toward measuring short and long-run adjustments to external imbalances. The literature has implemented dynamic time-series and panel estimators to test the relationship. Following recent literature, each chapter in this dissertation jointly focuses on the adjustment process of current account imbalances and the conditions required for capital mobility. The intent of this study is to show through the use of new estimation techniques previous results have been largely misguided. The starting point for this analysis is a thorough review of three key equations used in saving-investment regressions. The three models in question are an ordinary least squares model, error correction model, and an autoregressive distributive lag estimator. Each model is tested for stability, and it is found that a number of countries have an unstable relationship. One argument for the instability results is the presence of structural breaks. Previous literature has found that both variables follow non-stationary processes, but when using more powerful unit root tests and controlling for level shifts, both variables appear stationary. If each variable is stationary then previous methods assuming non-stationarity will produce incorrect inferences. Each series is optimally estimated for structural breaks, and through a mean differencing process the savings-investment coefficient is significantly reduced. Additionally, removing the exogenous breaks and using the lower frequency components allows for modeling the short-run current account adjustment process. Finally, the results are extended to measure the relationship in a panel framework using dynamic panel estimators and threshold effects. After controlling for structural breaks the coefficient decreases and exhibits a downward trend. The remaining correlation can be explained through trade openness and country size measures. / Committee: Nicolas Magud, Chairperson, Economics; Stephen Haynes, Member, Economics; Jeremy Piger, Member, Economics; Regina Baker, Outside Member, Political Science

xvii, 245 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / There has been a lot of research investigating the effects of heat stress and exercise on the physiological adaptations to heat acclimation. It is well documented that heat acclimation improves heat tolerance and performance in a hot environment; however, some of the mechanisms of adaptation are not clear. Furthermore, the role of heat acclimation on exercise performance in cool environments is currently unknown. Therefore, in Chapter IV we aimed to determine the effects of heat acclimation on lactate threshold and maximal oxygen uptake (VO 2max ) in cool and hot conditions. We also sought to investigate the effects of heat acclimation on leg blood flow and oxygen delivery during a single-leg knee extensor exercise. We found that heat acclimation improved lactate threshold and VO 2max in cool and hot environments but did not alter the leg blood flow and oxygen delivery during the leg kicking exercise. In Chapter V we investigated the heat acclimation effects on performance during a 1-hour time trial in hot and cool environmental conditions and the potential mechanisms by which this occurs. A secondary objective was to study whether the pacing strategy was modified during the time trial post-heat acclimation. The results demonstrated that heat acclimation improved time trial performance in both thermal environments by approximately 7% but pacing strategy was not altered. The purpose of the studies in Chapter VI were twofold. First, we sought to investigate how heat acclimation affects the skin blood flow and sweating responses to pharmacological treatment with specific dosages of the muscarinic receptor agonist acetylcholine. Second, we examined the maximal skin blood flow responses to a period of heat acclimation by locally heating the forearm with a water spray device for 45 minutes and measured brachial artery blood flow via ultrasound. We found that heat acclimation increased sweat rate and skin blood flow responses to given concentrations of acetylcholine, suggesting a role for peripheral mechanisms. On the other hand, maximal skin blood flow remained unchanged after heat acclimation. / Committee in charge: Christopher Minson, Chairperson, Human Physiology; John Halliwill, Member, Human Physiology; Andrew Lovering, Member, Human Physiology; Michael Sawka, Member, Not from U of 0; Scott Frey, Outside Member, Psychology

Teste intradérmico avalia reação de hipersensibilidade a diversos agentes que possam apresentar poder reacional alérgico e são comumente utilizados para complementar o diagnóstico da dermatite atópica canina (DAC). Ainda não existe consenso sobre as concentrações de histamina e extratos alergênicos a serem utilizadas. Para determinar a concentração ideal de histamina, como controle positivo, e do limiar irritativo de extratos alergênicos em teste intradérmico é necessário que diversas concentrações sejam avaliadas em uma população bem numerosa de cães hígidos. O objetivo desta pesquisa foi avaliar em 160 cães sadios submetidos a teste intradérmico, quais seriam as concentrações de histamina e de extratos alergênicos consideradas ideais. A solução contendo 0,1 mg/mL de histamina foi considerada como parâmetro ideal, provocando reações cutâneas com diâmetro médio, mediana e desvio padrão, de 15,18 mm, 14,97 mm e 2,07 mm, respectivamente. A partir do estabelecimento da concentração de histamina, foram determinadas as concentrações ótimas dos extratos alergênicos, expressas em PNU/mL: 1.000 para Dermatophagoides pteronyssinus, 500 para D. farinae, 125 para Blomia tropicalis e 2.000 para Malassezia pachydermatis. Futuros estudos devem ser conduzidos em cães atópicos para verificação da acurácia dos testes intradérmicos realizados com essas concentrações. / Intradermal testing evaluates hipersensitivity reaction to different agents that can present allergic reactivity power. It is commonly used to complement canine atopic dermatitis diagnosis. There is still no consensus about histamine concentrations and allergen extracts to be used. The determination of the histamine ideal concentration as positive control and the irritant threshold of allergen extracts for intradermal testing, requires evaluation of different concentrations on a large population of healthy dogs. The purpose of this research was to evaluate the ideal histamine and allergen extracts concentrations on 160 healthy dogs submitted to intradermal testing. A histamine solution 0,1 mg/mL was considered the ideal parameter. It caused cutaneous reactions with average diameter, median measure and standard deviation of 15.18 mm, 14.97 mm and 2.07 mm, respectively. From the histamine concentration establishment, the optimum allergen extracts concentrations were determined, expressed by PNU/mL: 1.000 for Dermatophagoides pteronyssinus, 500 for D. farinae, 125 for Blomia tropicalis and 2.000 for Malassezia pachydermatis. Future studies have to be conducted on atopic dogs to verify the accuracy of the intradermal testing with these concentrations.

Este trabalho aborda o problema de dimensionamento portas lógicas e assinalamento de Vt para otimização de potência, área e temporização em circuitos integrados modernos. O fluxo proposto é aplicado aos conjuntos de circuitos de teste dos Concursos do International Symposium on Physical Design (ISPD) de 2012 e 2013. Este fluxo também é adapatado e avaliado nos estágios pós posicionamento e roteamento global em projetos industriais de circuitos integrados, que utilizam uma ferramenta precisa de análise estática de temporização. As técnicas propostas geram as melhores soluções para todos os circuitos de teste do Concurso do ISPD 2013 (no qual foi a ferramenta vencedora), com em média 8% menos consumo de potência estática quando comparada com os outros concorrentes. Além disso, após algumas modificações nos algoritmos, nós reduzimos o consumo em mais 10% em média a pontência estáticas com relação aos resultados do concurso. O foco deste trabalho é desenvolver e aplicar um algoritmo estado-da-arte de seleção portas lógicas para melhorar ainda mais projetos industriais de alto desempenho já otimizados após as fases de posicionamento e roteamento do fluxo de projeto físico industrial. Vamos apresentar e discutir vários problemas encontrados quando da aplicação de técnicas de otimização global em projetos industriais reais que não são totalmente cobertos em publicações encontradas na literatura. Os métodos propostos geram as melhores soluções para todos os circuitos de referência no Concurso do ISPD 2013, no qual foi a solução vencedora. Considerando a aplicação industrial, as técnicas propostas reduzem a potência estática em até 18,2 %, com redução média de 10,4 %, sem qualquer degradação na qualidade de temporização do circuito. / This work addresses the gate sizing and Vt assignment problem for power, area and timing optimization in modern integrated circuits (IC). The proposed flow is applied to the Benchmark Suites of the International Symposium on Physical Design (ISPD) 2012 and 2013 Contests. It is also adapted and evaluated in the post placement and post global routing stage of an industrial IC design flow using a sign-off static timing analysis engine. The proposed techniques are able to generate the best solutions for all benchmarks in the ISPD 2013 Contest (in which we were the winning team), with on average 8% lower leakage with respect to all other contestants. Also, after some refinements in the algorithms, we reduce leakage by another 10% on average over the contest results. The focus of this work is to develop and apply a state-of-the-art cell selection algorithm to further improve already optimized high-performance industrial designs after the placement and routing stages of the industrial physical design flow. We present the basic concepts involved in the gate sizing problem and how earlier literature addresses it. Several problems found when applying global optimization techniques in real-life industrial designs, which are not fully covered in publications found in literature, are presented and discussed. Considering the industrial application, the proposed techniques reduce leakage power by up to 18.2%, with average reduction of 10.4% without any degradation in timing quality.

Introdução: Os opioides são os analgésicos mais efetivos para tratamento da dor moderada a intensa. No entanto, evidências crescentes têm demonstrado que seu uso pode levar a mudanças na sensibilidade dolorosa. Nesse contexto, a hiperalgesia induzida pelo remifentanil (r-IH) envolve um desequilíbrio nos sistemas inibitórios e excitatórios. Postula-se que um dos mecanismos centrais seja a disfunção do sistema modulador descendente da dor. Então, neste estudo, testamos a hipótese de que a estimulação transcraniana de corrente contínua (ETCC), devido aos seus efeitos analgésicos, poderia prevenir a r-IH. Os desfechos primários incluíram a escala numérica de dor (END 0-10) durante o teste repetitivo ao frio (rCOLDT), e a alteração na END (0-10) durante o teste de modulação condicionada de dor (CPM-TASK). Os desfechos secundários foram os limiares de dor ao calor (HPT) e o tempo de reação durante o teste de dor à água gelada [zero graus oC, (IPT)]. Métodos: Ensaio clínico randomizado, fatorial, duplo cego, que incluiu 48 homens saudáveis, com idades entre 19 e 40 anos. Os sujeitos foram randomizados em quatro grupos (n=12): ativo (a) - ETCC / solução salina, Sham (s) - ETCC / solução salina, a-ETCC / remifentanil e s-ETCC / remifentanil. Foi aplicado o ETCC sobre o córtex motor primário, com uma sessão única de 20 min e 2 mA. Resultados: Durante o rCOLDT, houve um efeito significativo entre os grupos nos escores cumulativos da END (P = 0,01). O grupo s-ETCC / remifentanil apresentou maiores escores de dor durante rCOLDT, [media (SD) 5,49 (1,04)] e a-ETCC / remifentanil apresentaram escores relativamente menores [4,15 (1,62)]. Este achado mostra que o efeito da ETCC bloqueou a HI-R. Os grupos a-ETCC / solução salina e s-ETCC / salina apresentaram menor índice de dor durante rCOLDT, [3.11 (1.2)] e [3.15 (1.62)], respectivamente. A incidência de hiperalgesia definida como um aumento de 15% na END durante o rCOLDT foi de: 31% no grupo s-ETCC/remifentanil; 22% no grupo a-ETCC/remifentanil; 11% no grupo a-ETCC/salina; e 8.3% no grupo s-ETCC/salina. Os grupos com remifentanil apresentaram escore positivo na END (0-10) durante a tarefa CPM, ou seja, produziu um desengate do sistema modulador descendente de dor (DPMS). Além disso, s-ETCC / Remifentanil em comparação com a-ETCC/remifentanil apresentou menor HPT e maior tempo de reação durante o IPT. Conclusão: Esses achados sugerem que os efeitos da a-ETCC previne a disfunção da capacidade inibitória do sistema modulador descendente da dor induzido pelo remifentanil durante o rCOLDT. / Background: Opioids are the most effective analgesics to treat moderate to severe pain. However, growing evidence shows that opioids can elicit unexpected changes in pain sensitivity. In this sense, remifentanil-induced hyperalgesia (r-IH) involves an imbalance in the inhibitory and excitatory systems. It postulates that one of the central mechanisms is the dysfunction of the descending pain modulating system. We tested the hypothesis that transcranial Direct Current Stimulation (t-DCS), given its analgesics effects, could prevent r-IH. The primary outcomes included the Numerical Pain Score NPS (0-10) during the repetitive cold test (rCOLDT) and the change on the NPS (0-10) during the conditioned pain modulation (CPM)-task. The secondary outcomes were the heat pain threshold (HPT) and the reaction-time during the Ice-Water Pain Test (IPT). Methods: This double blinded, explanatory factorial randomized trial included 48 healthy males, ages ranging 19 to 40 years. They were randomized into four equal groups: active (a)-tDCS/saline, sham (s)-tDCS/saline, a-tDCS/remifentanil and s-tDCS/remifentanil. We applied tDCS over the primary motor-cortex, with a single session of 20 minutes and 2mA. Results: During the rCOLDT, there was a significant group effect on the cumulative NPS scores (P=0.01). The s-tDCS/remifentanil group presented larger pain scores during rCOLDT, [mean (SD) 5.49 (1.04)] and a-tDCS/remifentanil group had relative lower pain scores [4.15 (1.62)]; showing its blocking effect on r-IH. a-tDCS/saline and s-tDCS/saline groups showed lowest pain scores during rCOLDT, [3.11(1.2)] and [3.15(1.62)], respectively. The incidence of hyperalgesia defined as a 15% increase in NPS during rCOLDT was: 30.3% in the s-tDCS / remifentanil group; 22% in the a-tDCS / remifentanil group; 11% in the a- tDCS / saline group; 8.3% in the s-tDCS / saline group. Remifentanil groups showed positive scores in the NPS (0-10) during the CPM-task, that is, it produced a disengagement of the descending pain modulatory system (DPMS). Also, s- tDCS/Remifentanil compared to a-tDCS/Remifentanil showed lower HPT and larger reaction-time during the IPT. Conclusion: These findings suggest that the effects of a-tDCS prevents the dysfunction of the inhibitory capacity of the descending modulatory pain system induced by remifentanil during rCOLDT.