988 resultados para grid point selection


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Journal of Proteome Research (2006)5: 2720-2726

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RESUMO - Um dos grandes desafios actuais enfrentados pela Saúde Pública diz respeito ao fardo representado pelas doenças crónicas não transmissíveis enquanto co-responsáveis pela maioria das mortes que ocorrem no mundo, pela significativa e progressiva redução da qualidade de vida e aumento das incapacidades dos indivíduos afectados e por uma fasquia bastante elevada das despesas em saúde. Entretanto, a complexa dinâmica genética, biológica, psicológica, afectiva, sócio-cultural e ambiental que envolve o comportamento humano, tão amplamente relacionado com algumas destas doenças – doenças cardiovasculares, alguns tipos de cancro, obesidade, hipertensão, diabetes e doenças osteo-articulares – impõe o desafio constante da busca de novas e efectivas intervenções em promoção da saúde que influenciem positivamente os estilos de vida dos indivíduos, dos grupos e das comunidades. Sendo o sentido de coerência um traço da personalidade do indivíduo desenvolvido sob a influência directa ou indirecta dos mesmo factores acima referidos, o estabelecimento de uma relação entre este constructo e os comportamentos humanos pode revelar-se promissor para a elaboração de novas intervenções em promoção da saúde. Por sua vez, a gravidez, talvez por influência da ligação materno-fetal, pode representar um ponto de viragem na vida da mulher no que respeita ao sentido de coerência e aos comportamentos de saúde e um bom começo na vida do bebé que irá nascer sob a influência dos mesmos. Com a finalidade de contribuir para a construção de intervenções efectivas em promoção da saúde, através da descoberta de prováveis potencialidades salutogénicas dos constructos referidos – sentido de coerência e ligação materno-fetal –, foi desenvolvido um estudo quantitativo, observacional que teve por objectivos: ampliar o conhecimento sobre as mudanças do sentido de coerência no decorrer da vida, especificamente durante a gravidez; ampliar o conhecimento acerca das relações de alguns factores de natureza sócio-demográfica, psico-afectiva e obstétrica com o sentido de coerência das mulheres grávidas e com a ligação materno-fetal; e identificar possíveis relações entre o sentido de coerência, a ligação materno-fetal e o estilo de vida das mulheres grávidas, este último representado pelos hábitos alimentares, consumo de cafeína, consumo de álcool, hábitos tabágicos, prática regular de actividade física e ganho de peso durante a gravidez. O presente relatório descreve a concepção e os resultados deste estudo, que envolveu a uma amostra de 61 mulheres grávidas que estavam a ser acompanhadas nos serviços de saúde materna dos Centros de Saúde de Carnaxide extensão Linda-a-Velha e de Oeiras, no Distrito de Lisboa, Portugal, entre os meses de Fevereiro e Julho de 2005. Os resultados demonstram que, para a amostra de 61 mulheres grávidas que responderam ao inquérito por questionário de auto-resposta, foram encontradas associações estatisticamente significativas entre o sentido de coerência e a escolaridade e entre o sentido de coerência e a percepção do próprio estado de saúde. Além disso, foi encontrada alguma evidência das associações entre o sentido de coerência e a faixa etária, estado civil e rendimento mensal familiar e foi observada alguma tendência para que as mulheres grávidas com níveis de sentido de coerência mais elevados consumissem menos álcool do que as mulheres grávidas com níveis de sentido de coerência inferiores. Entretanto, as demais associações testadas não foram confirmadas. Relativamente à ligação materno-fetal, foram encontradas, para a amostra de 41 mulheres grávidas que participaram do segundo momento de colheita de dados do estudo, entre a 20ª e a 24ª semanas de gravidez, associações estatisticamente significativas com a escolaridade e o nível de rendimento familiar das mulheres grávidas, não tendo sido confirmadas as demais associações testadas. Embora não tenham sido estatisticamente evidenciadas as relações entre o sentido de coerência e a ligação materno-fetal e entre estes e os comportamentos de saúde, o carácter preliminar destes resultados, devido à subjectividade do processo de selecção não probabilístico da amostra estudada e à reduzida dimensão desta amostra, e a escassez de estudos descritos na literatura fazem com que seja prudente a realização de estudos de follow-up, com amostras de maiores dimensões, aleatórias e representativas da população, para que sejam estabelecidas quaisquer conclusões acerca destas questões.-----------------------------ABSTRACT - One of the greatest challenges faced by Public Health in nowadays is the burden represented by chronic diseases as co-responsible for the majority of deaths that occurs in the world, for the meaningful and progressive reduction of quality of life and increase of disabilities in affected individuals and for an important part of health expenses. However, the complexity of the genetic, biological, psychological, emotional, social, cultural and environmental dynamics that involves human behaviours related to some of these diseases – cardiovascular diseases, some kind of cancers, obesity, hypertension, diabetes and joint and bone diseases – poses the continuous challenge of searching for new and effective interventions of health promotion that positively influence individuals, groups and community lifestyles. Due to the fact that sense of coherence is an individual personality trace directly or indirectly influenced by the same factors listed above, the discovery of a relationship between this construct and human behaviours might be promising to the creation of new health promotion interventions. On the other hand, pregnancy may represent a turn point to the mother’s life and a good start in the baby’s life in relation to sense of coherence and health behaviours and It might occur because of the influence of maternal-fetal attachment. With the purpose of contributing with the creation of effective health promotion interventions through the discovery of probable salutogenic potentials in the referred constructs – sense of coherence and maternal-fetal attachment – , it was developed a quantitative observational study with the following objectives: to increase knowledge about changes in sense of coherence throughout life, specifically during pregnancy; to increase knowledge about the relationship between sense of coherence and maternal-fetal attachment and some social, demographical, psychological, emotional and obstetric factors of pregnant women; to identify probable relationships between sense of coherence, maternal-fetal attachment and pregnant women’s lifestyles, represented by diet habits, caffeine consumption, alcohol consumption, smoking habits, physical activity habits and weigh gain during pregnancy. This report describes the structure and the findings of this study involving a sample of 61 pregnant women who had been followed by health professionals in the mother health services of Carnaxide (Linda-a-Velha unity) and Oeiras Health Centres, in Lisbon, Portugal, between February and July of 2005. The results show that, for the 61 pregnant women who filled the self-reported questionnaire, it was found a statistically significant association between sense of coherence and education level. It was also found some evidence of the associations between sense of coherence and age, marital status and mensal household income and a trend toward pregnant women with higher levels of sense of coherence to drink less alcoholic beverages than pregnant women with lower levels of sense of coherence. However, the others associations tested were not confirmed. Regarding maternal-fetal attachment, it was found, for the sample of 41 women who participated in the second moment of data collection, between the 20th and the 24th week of pregnancy, statistically significant associations with education level and mensal household income. The others associations tested were not confirmed. Although the associations between sense of coherence and maternal-fetal attachment and between these constructs and health behaviours were not confirmed, all findings presented here are considered preliminary because of small dimension of sample and non-probabilistic criteria used for sample selection. What’s more, there are almost no studies described in the literature which could confirm or contradict these findings. Therefore, it is better to be careful and develop follow-up studies, with bigger and representative of population samples, before draw any conclusions about these theme.

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This paper presents a methodology for multi-objective day-ahead energy resource scheduling for smart grids considering intensive use of distributed generation and Vehicle- To-Grid (V2G). The main focus is the application of weighted Pareto to a multi-objective parallel particle swarm approach aiming to solve the dual-objective V2G scheduling: minimizing total operation costs and maximizing V2G income. A realistic mathematical formulation, considering the network constraints and V2G charging and discharging efficiencies is presented and parallel computing is applied to the Pareto weights. AC power flow calculation is included in the metaheuristics approach to allow taking into account the network constraints. A case study with a 33-bus distribution network and 1800 V2G resources is used to illustrate the performance of the proposed method.

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Recent changes in electricity markets (EMs) have been potentiating the globalization of distributed generation. With distributed generation the number of players acting in the EMs and connected to the main grid has grown, increasing the market complexity. Multi-agent simulation arises as an interesting way of analysing players’ behaviour and interactions, namely coalitions of players, as well as their effects on the market. MASCEM was developed to allow studying the market operation of several different players and MASGriP is being developed to allow the simulation of the micro and smart grid concepts in very different scenarios This paper presents a methodology based on artificial intelligence techniques (AI) for the management of a micro grid. The use of fuzzy logic is proposed for the analysis of the agent consumption elasticity, while a case based reasoning, used to predict agents’ reaction to price changes, is an interesting tool for the micro grid operator.

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The power systems operation in the smart grid context increases significantly the complexity of their management. New approaches for ancillary services procurement are essential to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. These approaches should include market mechanisms which allow the participation of small and medium distributed energy resources players in a competitive market environment. In this paper, an energy and ancillary services joint market model used by an aggregator is proposed, considering bids of several types of distributed energy resources. In order to improve economic efficiency in the market, ancillary services cascading market mechanism is also considered in the model. The proposed model is included in MASCEM – a multi-agent system electricity market simulator. A case study considering a distribution network with high penetration of distributed energy resources is presented.

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The use of demand response programs enables the adequate use of resources of small and medium players, bringing high benefits to the smart grid, and increasing its efficiency. One of the difficulties to proceed with this paradigm is the lack of intelligence in the management of small and medium size players. In order to make demand response programs a feasible solution, it is essential that small and medium players have an efficient energy management and a fair optimization mechanism to decrease the consumption without heavy loss of comfort, making it acceptable for the users. This paper addresses the application of real-time pricing in a house that uses an intelligent optimization module involving artificial neural networks.

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The rising usage of distributed energy resources has been creating several problems in power systems operation. Virtual Power Players arise as a solution for the management of such resources. Additionally, approaching the main network as a series of subsystems gives birth to the concepts of smart grid and micro grid. Simulation, particularly based on multi-agent technology is suitable to model all these new and evolving concepts. MASGriP (Multi-Agent Smart Grid simulation Platform) is a system that was developed to allow deep studies of the mentioned concepts. This paper focuses on a laboratorial test bed which represents a house managed by a MASGriP player. This player is able to control a real installation, responding to requests sent by the system operators and reacting to observed events depending on the context.

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This paper presents a modified Particle Swarm Optimization (PSO) methodology to solve the problem of energy resources management with high penetration of distributed generation and Electric Vehicles (EVs) with gridable capability (V2G). The objective of the day-ahead scheduling problem in this work is to minimize operation costs, namely energy costs, regarding the management of these resources in the smart grid context. The modifications applied to the PSO aimed to improve its adequacy to solve the mentioned problem. The proposed Application Specific Modified Particle Swarm Optimization (ASMPSO) includes an intelligent mechanism to adjust velocity limits during the search process, as well as self-parameterization of PSO parameters making it more user-independent. It presents better robustness and convergence characteristics compared with the tested PSO variants as well as better constraint handling. This enables its use for addressing real world large-scale problems in much shorter times than the deterministic methods, providing system operators with adequate decision support and achieving efficient resource scheduling, even when a significant number of alternative scenarios should be considered. The paper includes two realistic case studies with different penetration of gridable vehicles (1000 and 2000). The proposed methodology is about 2600 times faster than Mixed-Integer Non-Linear Programming (MINLP) reference technique, reducing the time required from 25 h to 36 s for the scenario with 2000 vehicles, with about one percent of difference in the objective function cost value.

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Intelligent electrical grids can be considered as the next generation of electrical energy transportation. The enormous potential leads to worldwide focus of research on the technology of smart grids. This paper aims to present a review of the Brazilian electricity sector in context with the integration of communication technologies for smart grids. The work gives an overview of the generation, transmission and distribution of electrical energy in the Brazil and a brief summary of the current electricity market. Smart grid technologies are introduced and the requirements for the Brazilian power system are pointed out. Various technologies for communication within an intelligent network are presented and their characteristics, advantages and disadvantages are compared to the Brazilian conditions. In addition, a summary is given of current pilot projects for Smart Grid technologies within Brazil, as well as a presentation of individual selected projects.

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Environmental concerns and the shortage in the fossil fuel reserves have been potentiating the growth and globalization of distributed generation. Another resource that has been increasing its importance is the demand response, which is used to change consumers’ consumption profile, helping to reduce peak demand. Aiming to support small players’ participation in demand response events, the Curtailment Service Provider emerged. This player works as an aggregator for demand response events. The control of small and medium players which act in smart grid and micro grid environments is enhanced with a multi-agent system with artificial intelligence techniques – the MASGriP (Multi-Agent Smart Grid Platform). Using strategic behaviours in each player, this system simulates the profile of real players by using software agents. This paper shows the importance of modeling these behaviours for studying this type of scenarios. A case study with three examples shows the differences between each player and the best behaviour in order to achieve the higher profit in each situation.

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This paper presents the characterization of high voltage (HV) electric power consumers based on a data clustering approach. The typical load profiles (TLP) are obtained selecting the best partition of a power consumption database among a pool of data partitions produced by several clustering algorithms. The choice of the best partition is supported using several cluster validity indices. The proposed data-mining (DM) based methodology, that includes all steps presented in the process of knowledge discovery in databases (KDD), presents an automatic data treatment application in order to preprocess the initial database in an automatic way, allowing time saving and better accuracy during this phase. These methods are intended to be used in a smart grid environment to extract useful knowledge about customers’ consumption behavior. To validate our approach, a case study with a real database of 185 HV consumers was used.

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Electric power networks, namely distribution networks, have been suffering several changes during the last years due to changes in the power systems operation, towards the implementation of smart grids. Several approaches to the operation of the resources have been introduced, as the case of demand response, making use of the new capabilities of the smart grids. In the initial levels of the smart grids implementation reduced amounts of data are generated, namely consumption data. The methodology proposed in the present paper makes use of demand response consumers’ performance evaluation methods to determine the expected consumption for a given consumer. Then, potential commercial losses are identified using monthly historic consumption data. Real consumption data is used in the case study to demonstrate the application of the proposed method.

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The increasing and intensive integration of distributed energy resources into distribution systems requires adequate methodologies to ensure a secure operation according to the smart grid paradigm. In this context, SCADA (Supervisory Control and Data Acquisition) systems are an essential infrastructure. This paper presents a conceptual design of a communication and resources management scheme based on an intelligent SCADA with a decentralized, flexible, and intelligent approach, adaptive to the context (context awareness). The methodology is used to support the energy resource management considering all the involved costs, power flows, and electricity prices leading to the network reconfiguration. The methodology also addresses the definition of the information access permissions of each player to each resource. The paper includes a 33-bus network used in a case study that considers an intensive use of distributed energy resources in five distinct implemented operation contexts.

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The Smart Grid environment allows the integration of resources of small and medium players through the use of Demand Response programs. Despite the clear advantages for the grid, the integration of consumers must be carefully done. This paper proposes a system which simulates small and medium players. The system is essential to produce tests and studies about the active participation of small and medium players in the Smart Grid environment. When comparing to similar systems, the advantages comprise the capability to deal with three types of loads – virtual, contextual and real. It can have several loads optimization modules and it can run in real time. The use of modules and the dynamic configuration of the player results in a system which can represent different players in an easy and independent way. This paper describes the system and all its capabilities.

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Enterprise and Work Innovation Studies,6,IET, pp.9-51