973 resultados para Visual Context
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The identification of core competencies which are important for undertaking accurate visual screening by orthoptists is considered in this study. The aim was to construct and validate a questionnaire for orthoptists to assess visual screening competency. This study comprised three steps. The first step involved a 69-item self-assessment questionnaire constructed to assess orthoptists' perception of their competencies in visual screening programs for children. This questionnaire was constructed with statements from the Orthoptic Benchmark Statement for Health Care Programmes (Quality Assurance Agency for Higher Education, UK) and included three competency dimensions: interpersonal (IP), instrumental (IT) and systemic (ST). The second step involved questionnaire translation.
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Introdução – Na avaliação diagnóstica em mamografia, o desempenho do radiologista pode estar sujeito a erros de diagnóstico. Objetivo – Descrever a importância da perceção visual na análise da mamografia, identificando os principais fatores que contribuem para a perceção visual do radiologista e que condicionam a acuidade diagnóstica. Metodologia – Estudo descritivo baseado numa revisão sistemática de literatura através da PubMed e da Science Direct. Foram incluídos 42 artigos que respeitavam, pelo menos, um dos critérios de inclusão no estudo. Para a seleção das referências foi utilizada a metodologia PRISMA, constituída por 4 fases: identificação, seleção preliminar, elegibilidade e estudos incluídos. Resultados – Na avaliação diagnóstica em mamografia, a perceção visual está intimamente relacionada com: 1) diferentes parâmetros visuais e da motilidade ocular (acuidade visual, sensibilidade ao contraste e à luminância e movimentos oculares); 2) com condições de visualização de uma imagem (iluminância da sala e luminância do monitor); e 3) fadiga ocular provocada pela observação diária consecutiva de imagens. Conclusões – A perceção visual pode ser influenciada por 3 categorias de erros observados: erros de pesquisa (lesões não são fixadas pela fóvea), erros de reconhecimento (lesões fixadas, mas não durante o tempo suficiente) e erros de decisão (lesões fixadas, mas não identificadas como suspeitas). Os estudos analisados sobre perceção visual, atenção visual e estratégia visual, bem como os estudos sobre condições de visualização não caracterizam a função visual dos observadores. Para uma avaliação correta da perceção visual em mamografia deverão ser efetuados estudos que correlacionem a função visual com a qualidade diagnóstica. ABSTRACT - Introduction – Diagnostic evaluation in mammography could be influenced by the radiologist performance that could be under diagnostic errors. Aims – To describe the importance of radiologist visual perception in mammographic diagnostic evaluation and to identify the main factors that contribute to diagnostic accuracy. Methods – In this systematic review 42 references were included based on inclusion criteria (PubMed and Science Direct). PRISMA method was used to select the references following 4 steps: identification, screening, eligibility and included references. Results – Visual perception in mammography diagnostic evaluation is related with: 1) visual parameters and ocular motility (visual acuity, contrast sensitivity and luminance and ocular movements); 2) image visualization environment (room iluminance and monitor luminance); and 3) eyestrain caused by image daily consecutive observation. Conclusions – Visual perception can be influenced by three errors categories: search errors (lesions are never looked at with high-resolution foveal vision), recognition errors (lesions are looked at, but not long enough to detect or recognize) and decision errors (lesions are looked at for long periods of time but are still missed). The reviewed studies concerning visual perception, visual attention, visual strategies and image visualization environment do not describe observer’s visual function. An accurate evaluation of visual perception in mammography must include visual function analysis.
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O estudo apresentado visava responder às necessidades emergentes de justificação da intervenção da Terapia Ocupacional na população idosa com deficiência visual. Teve como objectivo explorar as perspectivas dos idosos com deficiência visual na experiência que têm da sua participação ocupacional. Paralelamente a este objectivo procurou-se, também, conhecer as atitudes e comportamentos em relação ao apoio da Terapia Ocupacional. Para estudar estas questões utilizou-se uma metodologia qualitativa, a fenomenologia, que permitiu descrever fielmente a experiência que se pretendia conhecer. A recolha de dados foi feita através de duas sessões de focus groups distintas, onde num dos grupos participaram idosos com deficiência visual que tiveram apoio de Terapia Ocupacional e no outro idosos com deficiência visual que não usufruíram deste apoio. Após a análise do conteúdo resultante dos focus groups emergiram os seguintes temas: impacto da deficiência visual, onde foram englobadas as categorias de implicações psicossociais da deficiência visual e restrições nas actividades e ocupações do idoso com deficiência visual; o segundo tema onde se incluíram as categorias de apoio e atitudes sociais, instituições e recursos acessíveis e estratégias utilizadas; por fim o tema dos benefícios percebidos, do qual fazem parte as categorias, benefícios psicológicos e participação. Estes temas permitiram perceber as perspectivas de participação ocupacional do idoso, após o aparecimento da deficiência visual, bem como conhecer as melhorias ao nível dessa participação após intervenção especializada, destacando-se a relevância da intervenção do terapeuta ocupacional na população idosa com deficiência visual.
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Once in a digital form, a radiographic image may be processed in several ways in order to turn the visualization an act of improved diagnostic value. Practitioners should be aware that, depending on each clinical context, digital image processing techniques are available to help to unveil visual information that is, in fact, carried by the bare digital radiograph and may be otherwise neglected. The range of visual enhancement procedures includes simple techniques that deal with the usual brightness and contrast manipulation up to much more elaborate multi-scale processing that provides customized control over the emphasis given to the relevant finer anatomical details. This chapter is intended to give the reader a practical understanding of image enhancement techniques that might be helpful to improve the visual quality of the digital radiographs and thus to contribute to a more reliable and assertive reporting.
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Personal memories composed of digital pictures are very popular at the moment. To retrieve these media items annotation is required. During the last years, several approaches have been proposed in order to overcome the image annotation problem. This paper presents our proposals to address this problem. Automatic and semi-automatic learning methods for semantic concepts are presented. The automatic method is based on semantic concepts estimated using visual content, context metadata and audio information. The semi-automatic method is based on results provided by a computer game. The paper describes our proposals and presents their evaluations.
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The present research paper presents five different clustering methods to identify typical load profiles of medium voltage (MV) electricity consumers. These methods are intended to be used in a smart grid environment to extract useful knowledge about customer’s behaviour. The obtained knowledge can be used to support a decision tool, not only for utilities but also for consumers. Load profiles can be used by the utilities to identify the aspects that cause system load peaks and enable the development of specific contracts with their customers. The framework presented throughout the paper consists in several steps, namely the pre-processing data phase, clustering algorithms application and the evaluation of the quality of the partition, which is supported by cluster validity indices. The process ends with the analysis of the discovered knowledge. To validate the proposed framework, a case study with a real database of 208 MV consumers is used.
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Power systems have been through deep changes in recent years, namely with the operation of competitive electricity markets in the scope and the increasingly intensive use of renewable energy sources and distributed generation. This requires new business models able to cope with the new opportunities that have emerged. Virtual Power Players (VPPs) are a new player type which allows aggregating a diversity of players (Distributed Generation (DG), Storage Agents (SA), Electrical Vehicles, (V2G) and consumers), to facilitate their participation in the electricity markets and to provide a set of new services promoting generation and consumption efficiency, while improving players` benefits. A major task of VPPs is the remuneration of generation and services (maintenance, market operation costs and energy reserves), as well as charging energy consumption. This paper proposes a model to implement fair and strategic remuneration and tariff methodologies, able to allow efficient VPP operation and VPP goals accomplishment in the scope of electricity markets.
Using demand response to deal with unexpected low wind power generation in the context of smart grid
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Demand response is assumed an essential resource to fully achieve the smart grids operating benefits, namely in the context of competitive markets. Some advantages of Demand Response (DR) programs and of smart grids can only be achieved through the implementation of Real Time Pricing (RTP). The integration of the expected increasing amounts of distributed energy resources, as well as new players, requires new approaches for the changing operation of power systems. The methodology proposed aims the minimization of the operation costs in a smart grid operated by a virtual power player. It is especially useful when actual and day ahead wind forecast differ significantly. When facing lower wind power generation than expected, RTP is used in order to minimize the impacts of such wind availability change. The proposed model application is here illustrated using the scenario of a special wind availability reduction day in the Portuguese power system (8th February 2012).
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OBJETIVO: Investigar o desenvolvimento da linguagem e das funções auditiva e visual em lactentes de creche, a partir da avaliação realizada por educadores. MÉTODOS: Foram avaliados 115 lactentes, nos anos de 1998 a 2001, usuários de uma creche da área da saúde de uma universidade do Estado de São Paulo. Foi utilizado o "Protocolo da Observação do Desenvolvimento de Linguagem e das Funções Auditiva e Visual", com 39 provas no total, para a avaliação dos lactentes de 3 até 12 meses de idade. A aplicação desse Protocolo foi feita pelas educadoras da creche, devidamente treinadas. Utilizou-se o teste de Qui-quadrado ou Exato de Fisher. O nível de significância adotado foi de 5%. RESULTADOS: Os lactentes apresentaram um padrão diferente no desenvolvimento da linguagem quanto ao início do balbucio e das primeiras palavras, bem como na função visual, quanto à imitação e uso de jogos gestuais e de seguir ordem com uso de gestos. CONCLUSÕES: O ambiente creche propicia condições para um outro padrão de desenvolvimento de linguagem e das funções auditiva e visual. Ações de prevenção na creche devem integrar as áreas de saúde e educação num objetivo comum.
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OBJETIVO: A baixa acuidade visual tem elevada prevalência e o diagnóstico precoce é necessário pelos danos que pode causar ao desenvolvimento e aprendizado infantis. O estudo realizado objetivou descrever e analisar a prevalência de baixa acuidade visual em escolares da rede de ensino fundamental. MÉTODOS: A partir do diagnóstico da acuidade visual, 9.640 escolares de primeira e quarta séries da rede pública de ensino fundamental de Sorocaba, Estado de São Paulo, no ano 2000, foram analisados e classificados seus registros segundo sexo, série, uso de óculos, área de residência e grau de acesso à assistência médica supletiva. Foram realizados testes de correlação de Pearson e análise de regressão linear. RESULTADOS: A população estudada apresentou prevalência de baixa acuidade visual de 13,1% (IC 95%=12,5-13,8%), sendo significantemente menor no sexo masculino (11,5%) quando comparado ao feminino (14,9%) - (RP=0,77); significantemente maior nos escolares de primeira série (14,1%) quando comparados aos de quarta série (11,5%) - (RP=1,22); e significantemente menor em não-usuários de óculos (12,1%) quando comparados aos usuários (42,0%) - (RP=0,29). Dentre os locais estudados, o bairro de Cajuru apresentou a menor prevalência de baixa acuidade visual (1,8%) e o bairro de Vila Sabiá a maior prevalência (32,4%). Foi encontrada correlação positiva, segundo a área de residência entre a proporção de indivíduos que têm acesso à assistência médica supletiva e a proporção de usuários de óculos (r=0,64, p<0,001). CONCLUSÕES: A prevalência de baixa acuidade visual aponta falhas no diagnóstico precoce e na continuidade da assistência, indicando urgente necessidade de implementação de um programa público de saúde.
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The large increase of Distributed Generation (DG) in Power Systems (PS) and specially in distribution networks makes the management of distribution generation resources an increasingly important issue. Beyond DG, other resources such as storage systems and demand response must be managed in order to obtain more efficient and “green” operation of PS. More players, such as aggregators or Virtual Power Players (VPP), that operate these kinds of resources will be appearing. This paper proposes a new methodology to solve the distribution network short term scheduling problem in the Smart Grid context. This methodology is based on a Genetic Algorithms (GA) approach for energy resource scheduling optimization and on PSCAD software to obtain realistic results for power system simulation. The paper includes a case study with 99 distributed generators, 208 loads and 27 storage units. The GA results for the determination of the economic dispatch considering the generation forecast, storage management and load curtailment in each period (one hour) are compared with the ones obtained with a Mixed Integer Non-Linear Programming (MINLP) approach.
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Smart grids are envisaged as infrastructures able to accommodate all centralized and distributed energy resources (DER), including intensive use of renewable and distributed generation (DG), storage, demand response (DR), and also electric vehicles (EV), from which plug-in vehicles, i.e. gridable vehicles, are especially relevant. Moreover, smart grids must accommodate a large number of diverse types or players in the context of a competitive business environment. Smart grids should also provide the required means to efficiently manage all these resources what is especially important in order to make the better possible use of renewable based power generation, namely to minimize wind curtailment. An integrated approach, considering all the available energy resources, including demand response and storage, is crucial to attain these goals. This paper proposes a methodology for energy resource management that considers several Virtual Power Players (VPPs) managing a network with high penetration of distributed generation, demand response, storage units and network reconfiguration. The resources are controlled through a flexible SCADA (Supervisory Control And Data Acquisition) system that can be accessed by the evolved entities (VPPs) under contracted use conditions. A case study evidences the advantages of the proposed methodology to support a Virtual Power Player (VPP) managing the energy resources that it can access in an incident situation.
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Cyber-Physical Intelligence is a new concept integrating Cyber-Physical Systems and Intelligent Systems. The paradigm is centered in incorporating intelligent behavior in cyber-physical systems, until now too oriented to the operational technological aspects. In this paper we will describe the use of Cyber-Physical Intelligence in the context of Power Systems, namely in the use of Intelligent SCADA (Supervisory Control and Data Acquisition) systems at different levels of the Power System, from the Power Generation, Transmission, and Distribution Control Centers till the customers houses.
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In the energy management of a small power system, the scheduling of the generation units is a crucial problem for which adequate methodologies can maximize the performance of the energy supply. This paper proposes an innovative methodology for distributed energy resources management. The optimal operation of distributed generation, demand response and storage resources is formulated as a mixed-integer linear programming model (MILP) and solved by a deterministic optimization technique CPLEX-based implemented in General Algebraic Modeling Systems (GAMS). The paper deals with a vision for the grids of the future, focusing on conceptual and operational aspects of electrical grids characterized by an intensive penetration of DG, in the scope of competitive environments and using artificial intelligence methodologies to attain the envisaged goals. These concepts are implemented in a computational framework which includes both grid and market simulation.
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Demand response can play a very relevant role in future power systems in which distributed generation can help to assure service continuity in some fault situations. This paper deals with the demand response concept and discusses its use in the context of competitive electricity markets and intensive use of distributed generation. The paper presents DemSi, a demand response simulator that allows studying demand response actions and schemes using a realistic network simulation based on PSCAD. Demand response opportunities are used in an optimized way considering flexible contracts between consumers and suppliers. A case study evidences the advantages of using flexible contracts and optimizing the available generation when there is a lack of supply.