933 resultados para self-adaption two-control stabilization
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Family firm is a field of growing interest. The aim of this article is to understand whether CEOs identity impacts family firm’s stock returns. From a sample of Portuguese and Spanish family firms findings show that who manages the firms result in significantly different risk exposure. Moreover, we find that the abnormal return found by Fahlenbrach (2009) to founder-controlled firms disappear when we use valueweighted portfolios and include two new factors: market aggregate illiquidity and debt intensity to the four-factor Carhart model. Finally, our results explain why the majority of family firm is controlled by its founder.
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OBJECTIVE: To test discriminant analysis as a method of turning the information of a routine customer satisfaction survey (CSS) into a more accurate decision-making tool. METHODS: A 7-question, 10-multiple choice, self-applied questionnaire was used to study a sample of patients seen in two outpatient care units in Valparaíso, Chile, one of primary care (n=100) and the other of secondary care (n=249). Two cutting points were considered in the dependent variable (final satisfaction score): satisfied versus unsatisfied, and very satisfied versus all others. Results were compared with empirical measures (proportion of satisfied individuals, proportion of unsatisfied individuals and size of the median). RESULTS: The response rate was very high, over 97.0% in both units. A new variable, medical attention, was revealed, as explaining satisfaction at the primary care unit. The proportion of the total variability explained by the model was very high (over 99.4%) in both units, when comparing satisfied with unsatisfied customers. In the analysis of very satisfied versus all other customers, significant relationship was identified only in the case of the primary care unit, which explained a small proportion of the variability (41.9%). CONCLUSIONS: Discriminant analysis identified relationships not revealed by the previous analysis. It provided information about the proportion of the variability explained by the model. It identified non-significant relationships suggested by empirical analysis (e.g. the case of the relation very satisfied versus others in the secondary care unit). It measured the contribution of each independent variable to the explanation of the variation of the dependent one.
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In the sequence of the recent financial and economic crisis, the recent public debt accumulation is expected to hamper considerably business cycle stabilization, by enlarging the budgetary consequences of the shocks. This paper analyses how the average level of public debt in a monetary union shapes optimal discretionary fiscal and monetary stabilization policies and affects stabilization welfare. We use a two-country micro-founded New-Keynesian model, where a benevolent central bank and the fiscal authorities play discretionary policy games under different union-average debt-constrained scenarios. We find that high debt levels shift monetary policy assignment from inflation to debt stabilization, making cooperation welfare superior to noncooperation. Moreover, when average debt is too high, welfare moves directly (inversely) with debt-to-output ratios for the union and the large country (small country) under cooperation. However, under non-cooperation, higher average debt levels benefit only the large country.
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Characteristics of tunable wavelength pi'n/pin filters based on a-SiC:H multilayered stacked cells are studied both experimental and theoretically. Results show that the device combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal. An algorithm to decode the multiplex signal is established. A capacitive active band-pass filter model is presented and supported by an electrical simulation of the state variable filter circuit. Experimental and simulated results show that the device acts as a state variable filter. It combines the properties of active high-pass and low-pass filter sections into a capacitive active band-pass filter using a changing photo capacitance to control the power delivered to the load.
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Objectivo: descrever a intervenção em fisioterapia numa paciente com diagnóstico de epicondilalgia. Participantes e Métodos: estudo de caso de uma paciente que desenvolveu um quadro doloroso no cotovelo esquerdo no início de Janeiro de 2010 e em que a intervenção de fisioterapia teve início no princípio de Fevereiro de 2010. Foi utilizada uma variedade de técnicas articulares, nomeadamente a mobilização com movimento de Mulligan, aplicação de tape e manipulação cervical. O tratamento foi realizado em dias alternados e teve a duração total de duas semanas. Resultados: logo no final da primeira sessão a paciente referiu melhoria na dor à preensão. Na segunda sessão a paciente demonstrou capacidade de realizar auto-mobilização com movimento em casa. A regressão dos sintomas foi muito rápida durante as duas primeiras sessões, passou por uma fase de estabilização da terceira à quinta sessão, até à completa remissão no fim da sexta sessão. Conclusão: o processo de raciocínio clínico desenvolvido pelo fisioterapeuta durante as seis sessões de tratamento foi salientado. Após a recolha dos dados relativos à história e sua interpretação levantaram-se as primeiras hipóteses: epicondilalgia, disfunção cervical ou sindroma do túnel radial. No exame objectivo foram realizados testes para permitir a obtenção do diagnóstico diferencial – epicondilalgia; elaborou-se então um plano de intervenção em colaboração a paciente, que se mostrou eficaz, com resultados acima das expectativas.
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A marcha assegura uma progressão do corpo, compatível com o equilíbrio dinâmico e adaptada a potenciais factores destabilizadores, de um ponto de vista antecipatório, através de sinergias coordenadas entre os MSs, o tronco e os MIs. O tronco inferior tem um papel preponderante na marcha, sobretudo na estabilização necessária durante a fase de apoio. Esta actividade implica mobilidade pélvica e alongamento activo dos abdominais para conseguir a relação comprimento-tensão muscular óptima entre quadricípite e isquiotibiais, permitindo uma correcta sequência, timing e amplitude de activação. Nas crianças com alterações neuromotoras existem alterações no controlo do movimento e na estrutura do próprio movimento, alterando todo este processo. Como tal, este estudo tem como principal objectivo determinar a influência da actividade do tronco inferior na activação muscular proximal durante a fase de apoio da marcha, em crianças com quadro motor de diplegia, caracterizada por uma dificuldade na relação entre os membros e entre estes e o tronco. Para responder a este objectivo realizou-se um estudo de série de casos, com 2 crianças com quadro motor de diplegia. Efectuou-se EMG dos músculos abdominais, quadricípite e isquiotibiais e análise de imagem (para amplitude da CF) durante a marcha, em ambos os membros e em dois momentos de avaliação, separados por 2 meses, nos quais se realizou um protocolo de intervenção terapêutica adequado a cada caso. Os resultados indicam que a variação de amplitude da CF desde a fase de ataque ao solo à fase média de apoio é aproximadamente igual em M0e M1; concretamente, a amplitude inicial é inferior à de referência (pouca flexão) (melhor em M0) e a amplitude final é superior à de referência (pouca extensão) (melhor em M1). Estes resultados são idênticos em ambos os casos. Na EMG verificou-se uma actividade mais global e sincronizada de todos os músculos, mantendo-se aproximadamente a mesma percentagem de activação em M1, sobretudo no caso 1. No caso 2 verificou-se uma maior eficiência na variação da percentagem de activação dos abdominais, em M1, e dos isquiotibiais, à direita. Em conclusão, pode dizer-se que, em crianças com alterações neuromotoras (quadro motor de diplegia), uma actividade mais eficiente e sincronizada no tempo do tronco inferior, nomeadamente dos abdominais, contribui para uma maior capacidade de extensão da CF, durante a fase de apoio.
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Dissertação para a obtenção do Grau de Mestre em Contabilidade e Finanças Orientador: Mestre Adalmiro Álvaro Malheiro de Castro Andrade Pereira
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Power converters play a vital role in the integration of wind power into the electrical grid. Variable-speed wind turbine generator systems have a considerable interest of application for grid connection at constant frequency. In this paper, comprehensive simulation studies are carried out with three power converter topologies: matrix, two-level and multilevel. A fractional-order control strategy is studied for the variable-speed operation of wind turbine generator systems. The studies are in order to compare power converter topologies and control strategies. The studies reveal that the multilevel converter and the proposed fractional-order control strategy enable an improvement in the power quality, in comparison with the other power converters using a classical integer-order control strategy. (C) 2010 Elsevier Ltd. All rights reserved.
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This paper is on variable-speed wind turbines with permanent magnet synchronous generator (PMSG). Three different drive train mass models and three different topologies for the power-electronic converters are considered. The three different topologies considered are respectively a matrix, a two-level and a multilevel converter. A novel control strategy, based on fractional-order controllers, is proposed for the wind turbines. Simulation results are presented to illustrate the behaviour of the wind turbines during a converter control malfunction, considering the fractional-order controllers. Finally, conclusions are duly drawn. Copyright (C) 2010 John Wiley & Sons, Ltd.
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This paper describes an architecture conceived to integrate Power Sys-tems tools in a Power System Control Centre, based on an Ambient Intelligent (AmI) paradigm. This architecture is an instantiation of the generic architecture proposed in [1] for developing systems that interact with AmI environments. This architecture has been proposed as a consequence of a methodology for the inclu-sion of Artificial Intelligence in AmI environments (ISyRAmI - Intelligent Sys-tems Research for Ambient Intelligence). The architecture presented in the paper will be able to integrate two applications in the control room of a power system transmission network. The first is SPARSE expert system, used to get diagnosis of incidents and to support power restoration. The second application is an Intelligent Tutoring System (ITS) incorporating two training tools. The first tutoring tool is used to train operators to get the diagnosis of incidents. The second one is another tutoring tool used to train operators to perform restoration procedures.
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The efficacy of a larvicide, temephos, for controlling Ae. aegypti was evaluated in a cemetery in Buenos Aires, Argentina. Breeding sites decreased from 18.4% in the first study period (Nov 1998 to May 1999, without temephos) to 2.2% in the second period (Nov 1999 to May 2000, two applications), and to 0.05% in the third one (Nov 2000 to May 2001, five applications). Ovitraps with eggs decreased from 17% in the first period to 5.8% in the second period, and to 2.9% in the third one. Results suggest that, in Buenos Aires, Ae. aegypti populations are highly susceptible to temephos. It is recommended to limit the use of temephos to prevent potential epidemics rather than for routine control.
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Cyber-Physical Systems and Ambient Intelligence are two of the most important and emerging paradigms of our days. The introduction of renewable sources gave origin to a completely different dimension of the distribution generation problem. On the other hand, Electricity Markets introduced a different dimension in the complexity, the economic dimension. Our goal is to study how to proceed with the Intelligent Training of Operators in Power Systems Control Centres, considering the new reality of Renewable Sources, Distributed Generation, and Electricity Markets, under the emerging paradigms of Cyber-Physical Systems and Ambient Intelligence. We propose Intelligent Tutoring Systems as the approach to deal with the intelligent training of operators in these new circumstances.
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A novel agent-based approach to Meta-Heuristics self-configuration is proposed in this work. Meta-heuristics are examples of algorithms where parameters need to be set up as efficient as possible in order to unsure its performance. This paper presents a learning module for self-parameterization of Meta-heuristics (MHs) in a Multi-Agent System (MAS) for resolution of scheduling problems. The learning is based on Case-based Reasoning (CBR) and two different integration approaches are proposed. A computational study is made for comparing the two CBR integration perspectives. In the end, some conclusions are reached and future work outlined.
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The main purpose of this paper is to propose a Multi-Agent Autonomic and Bio-Inspired based framework with selfmanaging capabilities to solve complex scheduling problems using cooperative negotiation. Scheduling resolution requires the intervention of highly skilled human problem-solvers. This is a very hard and challenging domain because current systems are becoming more and more complex, distributed, interconnected and subject to rapidly changing. A natural Autonomic Computing (AC) evolution in relation to Current Computing is to provide systems with Self-Managing ability with a minimum human interference.
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Introdução – A dor predomina em muitas patologias médicas e acarreta diversas implicações para o doente. O presente estudo visou avaliar a eficácia de uma intervenção autossugestiva, como complemento ao tratamento médico, no aumento da autoeficácia e controlo da dor. Metodologia – Para a concretização deste objetivo, 205 pacientes adultos com dor foram distribuídos aleatoriamente por dois grupos que se distinguiram quanto à intervenção recebida durante 12 semanas, nomeadamente IAS (intervenção autossugestiva) e ISAS (intervenção sem autossugestão). Os dois grupos foram comparados quanto à evolução da autoeficácia e do controlo da dor ao longo desse período. Resultados e discussão – Os resultados mostraram um aumento estatisticamente significativo destas variáveis no grupo IAS mas não no grupo ISAS, sugerindo a eficácia da intervenção autossugestiva. Este estudo representa, assim, um importante contributo para a prática clínica com os doentes com dor.