901 resultados para well-structured transition systems
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As power systems grow in their size and interconnections, their complexity increases. Rising costs due to inflation and increased environmental concerns has made transmission, as well as generation systems be operated closer to design limits. Hence power system voltage stability and voltage control are emerging as major problems in the day-to-day operation of stressed power systems. For secure operation and control of power systems under normal and contingency conditions it is essential to provide solutions in real time to the operator in energy control center (ECC). Artificial neural networks (ANN) are emerging as an artificial intelligence tool, which give fast, though approximate, but acceptable solutions in real time as they mostly use the parallel processing technique for computation. The solutions thus obtained can be used as a guide by the operator in ECC for power system control. This paper deals with development of an ANN architecture, which provide solutions for monitoring, and control of voltage stability in the day-to-day operation of power systems.
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Rapid advancements in multi-core processor architectures coupled with low-cost, low-latency, high-bandwidth interconnects have made clusters of multi-core machines a common computing resource. Unfortunately, writing good parallel programs that efficiently utilize all the resources in such a cluster is still a major challenge. Various programming languages have been proposed as a solution to this problem, but are yet to be adopted widely to run performance-critical code mainly due to the relatively immature software framework and the effort involved in re-writing existing code in the new language. In this paper, we motivate and describe our initial study in exploring CUDA as a programming language for a cluster of multi-cores. We develop CUDA-For-Clusters (CFC), a framework that transparently orchestrates execution of CUDA kernels on a cluster of multi-core machines. The well-structured nature of a CUDA kernel, the growing popularity, support and stability of the CUDA software stack collectively make CUDA a good candidate to be considered as a programming language for a cluster. CFC uses a mixture of source-to-source compiler transformations, a work distribution runtime and a light-weight software distributed shared memory to manage parallel executions. Initial results on running several standard CUDA benchmark programs achieve impressive speedups of up to 7.5X on a cluster with 8 nodes, thereby opening up an interesting direction of research for further investigation.
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Silicon is the second most abundant element on the Earth and one of the more abundant elements in our Solar System. Variations in the relative abundance of the stable isotopes of Si (Si isotope fractionation) in different natural reservoirs, both terrestrial (surface and deep Earth) as well as extra-terrestrial (e.g. meteorites, lunar samples), are a powerful tracer of present and past processes involving abiotic as well as biotic systems. The versatility of the Si isotope tracer is reflected in its wide-ranging applications from understanding the origin of early Solar System objects, planetary differentiation, Moon formation, mantle melting and magma differentiation on the Earth, ancient sea-water composition, to modern-day weathering, clay formation and biological fractionation on land as well as in the oceans. The application of Si isotopes as tracers of natural processes started over six decades ago and its usage has seen a sudden increase over the last decade due to improvements in mass spectrometry, particularly the advent of multi-collector inductively coupled plasma mass spectrometers, which has made Si isotope measurements safe and relatively easy while simultaneously improving the accuracy and precision of measurements.
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[ES] El marco teórico del trabajo tiene como finalidad explicar los procesos de cooperación diseñados para las microempresas, con el propósito de establecer propuestas y argumentos para la formación de acuerdos, identificar los factores que afectan el desarrollo de los mismos, así como los sistemas de innovación nacional, regional y local para la animación de la cooperación entre firmas. Con ello, se propone una metodología para promover la cooperación entre microempresas, coordinada por agentes locales y la administración pública de los proyectos Micro y e-Micro (2002-2007) de la ciudad de Murcia.
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The DADAISM project brings together researchers from the diverse fields of archaeology, human computer interaction, image processing, image search and retrieval, and text mining to create a rich interactive system to address the problems of researchers finding images relevant to their research. In the age of digital photography, thousands of images are taken of archaeological artefacts. These images could help archaeologists enormously in their tasks of classification and identification if they could be related to one another effectively. They would yield many new insights on a range of archaeological problems. However, these images are currently greatly underutilized for two key reasons. Firstly, the current paradigm for interaction with image collections is basic keyword search or, at best, simple faceted search. Secondly, even if these interactions are possible, the metadata related to the majority of images of archaeological artefacts is scarce in information relating to the content of the image and the nature of the artefact, and is time intensive to enter manually. DADAISM will transform the way in which archaeologists interact with online image collections. It will deploy user-centred design methodologies to create an interactive system that goes well beyond current systems for working with images, and will support archaeologists’ tasks of finding, organising, relating and labelling images as well as other relevant sources of information such as grey literature documents.
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In 2003, twelve marine protected areas were established in state waters (0-3 nmi) surrounding the Channel Islands. NOAA is considering extending this network (3-6 nmi) into deeper waters of the Channel Islands National Marine Sanctuary (CINMS). In order for effective long-term management of the deep water reserves to occur, a well-structured monitoring program is required to assess effectiveness. The CINMS and the National Marine Sanctuary Program (NMSP) hosted a 2-day workshop in April 2005 to develop a monitoring plan for the proposed federal marine reserves in that sanctuary. Conducted at the University of California at Santa Barbara, participants included scientists from academic, state, federal, and private research institutions. Workshop participants developed project ideas that could answer priority questions posed by the NMSP. This workshop report will be used to develop a monitoring plan for the reserves. (PDF contains 47 pages.)
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Durante a década de 1970, ocorreu, no Brasil, a fase pioneira de internacionalização das empresas privadas brasileiras do setor de prestação de serviços de engenharia de construção. Essa internacionalização deu-se, apesar da ausência de uma política estruturada do setor público. A incapacidade estatal de perceber esse processo como algo profícuo em seus planos, impediu o governo de criar uma política consolidada para a multiplicação dessas empresas no exterior. Essa miopia estatal é percebida tanto na esfera da política doméstica, voltada para manter uma política de substituição de importação dentro das fronteiras, como, na política externa, ao desenvolver uma internacionalização das empresas públicas ao invés das do setor privado. Essa situação pode ser percebida no caso analisado da empresa privada brasileira Mendes Júnior, que ingressou no mercado iraquiano mais por conta própria do que em decorrência de uma política estatal brasileira.
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Apesar da definição da Estratégia de Saúde da Família (ESF) como porta de entrada preferencial do sistema de saúde e estratégia de reorganização da assistência, os usuários do SUS, vêm demonstrando historicamente preferência pelo serviço de urgência/emergência hospitalar. Neste contexto, o campo do presente estudo é a cidade de Piraí e seus habitantes, que desde 2002 contam com 100% de cobertura da ESF, modelo que dá ênfase: à lógica territorial na assistência, no cuidado continuado e transversal, no vínculo e no acesso facilitado pelo acolhimento humanizado e escuta qualificada; ocupando o centro da rede de serviços atuando como ordenador e coordenador do cuidado. Avaliando os dados de produtividade (com foco nas consultas médicas) hospitalar e da ESF notamos que a busca por assistência médica hospitalar, tem aumentado exponencialmente, e pode-se perceber que a grande maioria destes usuários se apresenta ao serviço com demandas de atenção básica, o que é considerado ilógico e contraditório na visão de gestores e profissionais. A prática profissional tem me levado a um processo de reflexão sobre as expectativas dos usuários ao procurarem o sistema de saúde (principalmente a ESF), sobre os caminhos que cada um deles constrói diante de uma questão de saúde e como se dá a tomada de decisão em busca da resolutividade da questão. Dessa forma, o objetivo deste trabalho é compreender como se constrói essa demanda; que critérios estão envolvidos na tomada de decisão desses usuários ao optarem pelo serviço de emergência como porta de entrada preferencial; mesmo em um município que oferece um serviço estruturado, pautado nas diretrizes da ESF e com uma cobertura que alcança toda a sua população. Acreditamos que o processo conhecido como medicalização da vida, que descreve o processo pelo qual problemas não médicos são definidos e tratados como problemas médicos, usualmente em termos de doenças e desordens (CONRAD, 2007); influencie na construção dessa demanda. Quanto a metodologia, foram realizadas entrevistas semiestruturadas, com usuários do SUS, residentes no município e que buscaram espontaneamente o serviço de urgência/emergência hospitalar. Verificou-se que a imagem que o usuário faz dos serviços de saúde se relaciona principalmente com o tempo de espera pelo atendimento, o acesso (interpretado principalmente como a certeza/incerteza do atendimento) e a acessibilidade. Os usuários frequentemente se referem à organização das unidades da ESF com o significado de barreiras ao acesso (principalmente pela necessidade de agendamento) e demonstram ter em relação às USF uma imagem de grande limitação de recursos humanos (quase exclusivamente em relação ao médico) e materiais. Por outro lado, prontos-socorros e hospitais se apresentam para eles, por várias razões, como espaços de acesso garantido. É importante ressaltar que o processo de medicalização da vida aparece como parte importante da engrenagem que move a construção dessa demanda.
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The purpose of this study was to investigate polychlorinated biphenyls (PCBs) contamination in tilapia (Oreochromis mossambicus) collected from the Manna stream and Ala Wai Canal of O'ahu, an island of the geographically isolated Hawaiian archipelago. Our results show that the average concentrations of PCBs varied from 51.90 to 89.42 ng g(-1) lipid weight for the sampling sites. Relative toxic potencies (RTPs) and toxic equivalencies (TEQs) were determined to be 20.38-40.60 ng TCDD g(-1) lipid weight and 2.89-4.17 ng TEQ g(-1) lipid weight by 7-ethoxy-resorufin-O-deethylase (EROD) activity analysis and calculation of PCB concentrations based on toxic equivalency factors (TEFs), respectively. Penta-chlorinated congeners were found to be predominant, which revealed that Aroclor 1254 was a possible major source of PCBs in our fish samples. PCB 118, an indicator PCBs, constituted more than 55% and 30% of the total PCBs and TEQs, respectively. In addition, PCB 118 was found to have a linear correlation to the total PCBs (R = 0.975) and TEQs (R = 0.782). Detection of concentrated PCBs in Hawaiian waters suggests a potentially adverse impact of this pollutant on human health, as well as ecological systems, and suggests the necessity of environmental monitoring and hazard assessment of PCBs within the Hawaiian Islands. (c) 2008 Published by Elsevier Ltd.
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A comparative study was conducted to reveal the differentiate effects of eight different filter media including gravel, zeolites, anthracite, shale, vermiculite, ceramic filter media, blast furnace steel slag and round ceramsite. The study mainly related to the eight different filter media's removal performances of organic matter, nitrogen and phosphorus in the vertical flow constructed wetland simulated system, which treating wastewater at hydraulic loading rate of 1000-2500 mm/d. The results indicated that the removal effects were closely related to the physical and chemical properties of medium materials. Anthracite-filled system had the highest removal rate for the total organic carbon (TOC), up to 70%, and the removal rates of other systems ranged from 20% to 30%. As for the five-day biochemical oxygen demand (BOD5), anthracite-filled and steel slag-filled systems had the highest removal rates, also up to 70%, as well as other systems all exceeded 50%. At the same time, for the total nitrogen (TN) and NH4(+)-N, the zeolites-filled and ceramic-filled systems had the best performances with the removal rates of more than 70%, the other way round, the removal rates of other systems were only about 20%. The distinguishable effects were also observed in removal performances of total phosphorus (TP) and total dissoluble phosphorus (TDP). The removal rates of TP and TDP in steel slag-filled systems were more than 90%, a much higher value, followed by that of the anthracite-filled system, more than 60%, but those of other systems being the less. Our study provided a potential mechanism to optimize the filter media design for the vertical flow constructed wetlands.
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The Design Patterns book [GOF95] presents 24 time-tested patterns that consistently appear in well-designed software systems. Each pattern is presented with a description of the design problem the pattern addresses, as well as sample implementation code and design considerations. This paper explores how the patterns from the "Gang of Four'', or "GOF'' book, as it is often called, appear when similar problems are addressed using a dynamic, higher-order, object-oriented programming language. Some of the patterns disappear -- that is, they are supported directly by language features, some patterns are simpler or have a different focus, and some are essentially unchanged.
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The small airways of the human lung undergo pathological changes in pulmonary disorders, such as chronic obstructive pulmonary disease (COPD), asthma, bronchiolitis obliterans and cystic fibrosis. These clinical problems impose huge personal and societal healthcare burdens. The changes, termed 'pathological airway remodeling', affect the epithelium, the underlying mesenchyme and the reciprocal trophic interactions that occur between these tissues. Most of the normal human airway is lined by a pseudostratified epithelium of ciliated cells, secretory cells and 6-30% basal cells, the proportion of which varies along the proximal-distal axis. Epithelial abnormalities range from hypoplasia (failure to differentiate) to basal- and goblet-cell hyperplasia, squamous- and goblet-cell metaplasia, dysplasia and malignant transformation. Mesenchymal alterations include thickening of the basal lamina, smooth muscle hyperplasia, fibrosis and inflammatory cell accumulation. Paradoxically, given the prevalence and importance of airway remodeling in lung disease, its etiology is poorly understood. This is due, in part, to a lack of basic knowledge of the mechanisms that regulate the differentiation, maintenance and repair of the airway epithelium. Specifically, little is known about the proliferation and differentiation of basal cells, a multipotent stem cell population of the pseudostratified airway epithelium. This Perspective summarizes what we know, and what we need to know, about airway basal cells to evaluate their contributions to normal and abnormal airway remodeling. We contend that exploiting well-described model systems using both human airway epithelial cells and the pseudostratified epithelium of the genetically tractable mouse trachea will enable crucial discoveries regarding the pathogenesis of airway disease.
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Quasi-Newton methods are applied to solve interface problems which arise from domain decomposition methods. These interface problems are usually sparse systems of linear or nonlinear equations. We are interested in applying these methods to systems of linear equations where we are not able or willing to calculate the Jacobian matrices as well as to systems of nonlinear equations resulting from nonlinear elliptic problems in the context of domain decomposition. Suitability for parallel implementation of these algorithms on coarse-grained parallel computers is discussed.
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Objectives This student selected component (SSC) was designed to equip United Kingdom (UK) medical students to respond ethically and with sensitivity to requests they might receive as qualified doctors in regard to euthanasia and assisted dying. The aim was to expose students to relevant opinions and experiences and to provide opportunities to explore and justify their own views and rehearse ethical decision making in a safe learning environment. Method The module is delivered by specialists from a number of disciplines including law, theology, medicine and nursing, each providing students with a working knowledge allowing them to actively discuss cases, articulate their own views and practise ethical reasoning through group and individual study. Visits to local intensive care units, palliative care wards and hospices are integrated effectively with theory. Student assessment comprises a dissertation, student-led debate and reflective commentary. Module impact was evaluated by analysis of student coursework and a questionnaire. Results Students found the content stimulating and relevant to their future career and agreed that the module was well-structured and that learning outcomes were achieved. They greatly appreciated the clinical context provided by the visits and opportunities to apply ethical reasoning to real cases and to debate ethical issues with peers. Students reported an increased discernment of the ethical and legal position and practical considerations and a greater awareness of the range of professional and lay viewpoints held. Student perceptions were confirmed on analysis of their submitted coursework. Many participants were less strongly in favour of euthanasia and assisted dying on module completion than at the outset but all felt better equipped to justify their own viewpoint and to respond appropriately to patient requests. Conclusions The multi-disciplinary nature of this course is helpful in preparing students to deal effectively and sensitively with ethical dilemmas they will encounter in their medical career. Use of an integrated, learner-centred approach equips students to actively engage with their peers in discussion of such issues and to formulate and defend their own position.