914 resultados para case-based reasoning (CBR)


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L’augmentation de la croissance des réseaux, des blogs et des utilisateurs des sites d’examen sociaux font d’Internet une énorme source de données, en particulier sur la façon dont les gens pensent, sentent et agissent envers différentes questions. Ces jours-ci, les opinions des gens jouent un rôle important dans la politique, l’industrie, l’éducation, etc. Alors, les gouvernements, les grandes et petites industries, les instituts universitaires, les entreprises et les individus cherchent à étudier des techniques automatiques fin d’extraire les informations dont ils ont besoin dans les larges volumes de données. L’analyse des sentiments est une véritable réponse à ce besoin. Elle est une application de traitement du langage naturel et linguistique informatique qui se compose de techniques de pointe telles que l’apprentissage machine et les modèles de langue pour capturer les évaluations positives, négatives ou neutre, avec ou sans leur force, dans des texte brut. Dans ce mémoire, nous étudions une approche basée sur les cas pour l’analyse des sentiments au niveau des documents. Notre approche basée sur les cas génère un classificateur binaire qui utilise un ensemble de documents classifies, et cinq lexiques de sentiments différents pour extraire la polarité sur les scores correspondants aux commentaires. Puisque l’analyse des sentiments est en soi une tâche dépendante du domaine qui rend le travail difficile et coûteux, nous appliquons une approche «cross domain» en basant notre classificateur sur les six différents domaines au lieu de le limiter à un seul domaine. Pour améliorer la précision de la classification, nous ajoutons la détection de la négation comme une partie de notre algorithme. En outre, pour améliorer la performance de notre approche, quelques modifications innovantes sont appliquées. Il est intéressant de mentionner que notre approche ouvre la voie à nouveaux développements en ajoutant plus de lexiques de sentiment et ensembles de données à l’avenir.

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A link between patterns of pelvic growth and human life history is supported by the finding that, cross-culturally, variation in maturation rates of female pelvis are correlated with variation in ages of menarche and first reproduction, i.e., it is well known that the human dimensions of the pelvic bones depend on the gender and vary with the age. Indeed, one feature in which humans appear to be unique is the prolonged growth of the pelvis after the age of sexual maturity. Both the total superoinferior length and mediolateral breadth of the pelvis continues to grow markedly after puberty, and do not reach adult proportions until the late teens years. This continuation of growth is accomplished by relatively late fusion of the separate centers of ossification that form the bones of the pelvis. Hence, in this work we will focus on the development of an intelligent decision support system to predict individual’s age based on a pelvis' dimensions criteria. Some basic image processing techniques were applied in order to extract the relevant features from pelvic X-rays, being the computational framework built on top of a Logic Programming approach to Knowledge Representation and Reasoning that caters for the handling of incomplete, unknown, or even self-contradictory information, complemented with a Case Base approach to computing.

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Dyscalculia is usually perceived of as a specific learning difficulty for mathematics or, more appropriately, arithmetic. Because definitions and diagnoses of dyscalculia are in their infancy and sometimes are contradictory. However, mathematical learning difficulties are certainly not in their infancy and are very prevalent and often devastating in their impact. Co-occurrence of learning disorders appears to be the rule rather than the exception. Co-occurrence is generally assumed to be a consequence of risk factors that are shared between disorders, for example, working memory. However, it should not be assumed that all dyslexics have problems with mathematics, although the percentage may be very high, or that all dyscalculics have problems with reading and writing. Because mathematics is very developmental, any insecurity or uncertainty in early topics will impact on later topics, hence to need to take intervention back to basics. However, it may be worked out in order to decrease its degree of severity. For example, disMAT, an app developed for android may help children to apply mathematical concepts, without much effort, that is turning in itself, a promising tool to dyscalculia treatment. Thus, this work will focus on the development of a Decision Support System to estimate children evidences of dyscalculia, based on data obtained on-the-fly with disMAT. The computational framework is built on top of a Logic Programming approach to Knowledge Representation and Reasoning, grounded on a Case-based approach to computing, that allows for the handling of incomplete, unknown, or even self-contradictory information.

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Conferences that deliver interactive sessions designed to enhance physician participation, such as role play, small discussion groups, workshops, hands-on training, problem- or case-based learning and individualised training sessions, are effective for physician education.

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This paper examines the proposition that the traditional archetype of the professional partnership is said to have changed into a more 'business-like' entity, the managed professional business. It broadens the restricted case sample base on which much of the evidence has been adduced, by developing a survey questionnaire through which 197 large British law firms were sampled. Change, consistent with the notion of a more commercially oriented and consciously managed organization, is concentrated in the market-facing area of the firm but coexists with areas of continuity in the governance of the firm and its strategic management. The findings reveal a more managerial form of organization in which the core elements of the traditional form of professional organization have not been transformed. These results contest the assertion of either transformational or sedimented change found in other, case-based research and suggest that archetype change needs theoretically to be distinguished from the general phenomenon of greater managerialism within the professional service firm.

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This paper is on the problem of short-term hydro scheduling (STHS), particularly concerning a head-dependent hydro chain We propose a novel mixed-integer nonlinear programming (MINLP) approach, considering hydroelectric power generation as a nonlinear function of water discharge and of the head. As a new contribution to eat her studies, we model the on-off behavior of the hydro plants using integer variables, in order to avoid water discharges at forbidden areas Thus, an enhanced STHS is provided due to the more realistic modeling presented in this paper Our approach has been applied successfully to solve a test case based on one of the Portuguese cascaded hydro systems with a negligible computational time requirement.

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A liberalização do sector eléctrico, e a consequente criação de mercados de energia eléctrica regulados e liberalizados, mudou a forma de comercialização da electricidade. Em particular, permitiu a entrada de empresas nas actividades de produção e comercialização, aumentando a competitividade e assegurando a liberdade de escolha dos consumidores, para decidir o fornecedor de electricidade que pretenderem. A competitividade no sector eléctrico aumentou a necessidade das empresas que o integram a proporem preços mais aliciantes (do que os preços propostos pelos concorrentes), e contribuiu para o desenvolvimento de estratégias de mercado que atraiam mais clientes e aumentem a eficiência energética e económica. A comercialização de electricidade pode ser realizada em mercados organizados ou através de contratação directa entre comercializadores e consumidores, utilizando os contratos bilaterais físicos. Estes contratos permitem a negociação dos preços de electricidade entre os comercializadores e os consumidores. Actualmente, existem várias ferramentas computacionais para fazer a simulação de mercados de energia eléctrica. Os simuladores existentes permitem simulações de transacções em bolsas de energia, negociação de preços através de contratos bilaterais, e análises técnicas a redes de energia. No entanto, devido à complexidade dos sistemas eléctricos, esses simuladores apresentam algumas limitações. Esta dissertação apresenta um simulador de contratos bilaterais em mercados de energia eléctrica, sendo dando ênfase a um protocolo de ofertas alternadas, desenvolvido através da tecnologia multi-agente. Em termos sucintos, um protocolo de ofertas alternadas é um protocolo de interacção que define as regras da negociação entre um agente vendedor (por exemplo um retalhista) e um agente comprador (por exemplo um consumidor final). Aplicou-se o simulador na resolução de um caso prático, baseado em dados reais. Os resultados obtidos permitem concluir que o simulador, apesar de simplificado, pode ser uma ferramenta importante na ajuda à tomada de decisões inerentes à negociação de contratos bilaterais em mercados de electricidade.

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In the aftermath of a large-scale disaster, agents' decisions derive from self-interested (e.g. survival), common-good (e.g. victims' rescue) and teamwork (e.g. fire extinction) motivations. However, current decision-theoretic models are either purely individual or purely collective and find it difficult to deal with motivational attitudes; on the other hand, mental-state based models find it difficult to deal with uncertainty. We propose a hybrid, CvI-JI, approach that combines: i) collective 'versus' individual (CvI) decisions, founded on the Markov decision process (MDP) quantitative evaluation of joint-actions, and ii)joint-intentions (JI) formulation of teamwork, founded on the belief-desire-intention (BDI) architecture of general mental-state based reasoning. The CvI-JI evaluation explores the performance's improvement

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This paper proposes two meta-heuristics (Genetic Algorithm and Evolutionary Particle Swarm Optimization) for solving a 15 bid-based case of Ancillary Services Dispatch in an Electricity Market. A Linear Programming approach is also included for comparison purposes. A test case based on the dispatch of Regulation Down, Regulation Up, Spinning Reserve and Non-Spinning Reserve services is used to demonstrate that the use of meta-heuristics is suitable for solving this kind of optimization problem. Faster execution times and lower computational resources requirements are the most relevant advantages of the used meta-heuristics when compared with the Linear Programming approach.

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Electricity market players operating in a liberalized environment requires access to an adequate decision support tool, allowing them to consider all the business opportunities and take strategic decisions. Ancillary services represent a good negotiation opportunity that must be considered by market players. For this, decision support tool must include ancillary market simulation. This paper proposes two different methods (Linear Programming and Genetic Algorithm approaches) for ancillary services dispatch. The methodologies are implemented in MASCEM, a multi-agent based electricity market simulator. A test case based on California Independent System Operator (CAISO) data concerning the dispatch of Regulation Down, Regulation Up, Spinning Reserve and Non-Spinning Reserve services is included in this paper.

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Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Hidráulica

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Purpose - The study evaluates the pre- and post-training lesion localisation ability of a group of novice observers. Parallels are drawn with the performance of inexperienced radiographers taking part in preliminary clinical evaluation (PCE) and ‘red-dot’ systems, operating within radiography practice. Materials and methods - Thirty-four novice observers searched 92 images for simulated lesions. Pre-training and post-training evaluations were completed following the free-response the receiver operating characteristic (FROC) method. Training consisted of observer performance methodology, the characteristics of the simulated lesions and information on lesion frequency. Jackknife alternative FROC (JAFROC) and highest rating inferred ROC analyses were performed to evaluate performance difference on lesion-based and case-based decisions. The significance level of the test was set at 0.05 to control the probability of Type I error. Results - JAFROC analysis (F(3,33) = 26.34, p < 0.0001) and highest-rating inferred ROC analysis (F(3,33) = 10.65, p = 0.0026) revealed a statistically significant difference in lesion detection performance. The JAFROC figure-of-merit was 0.563 (95% CI 0.512,0.614) pre-training and 0.677 (95% CI 0.639,0.715) post-training. Highest rating inferred ROC figure-of-merit was 0.728 (95% CI 0.701,0.755) pre-training and 0.772 (95% CI 0.750,0.793) post-training. Conclusions - This study has demonstrated that novice observer performance can improve significantly. This study design may have relevance in the assessment of inexperienced radiographers taking part in PCE or commenting scheme for trauma.

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O presente trabalho foi realizado com o intuito de dar a conhecer, de um modo mais pormenorizado, os diferentes tipos de sistemas de revestimento de fachadas em zinco. Numa primeira fase abordou-se as características do metal zinco, assim como uma breve explicação do seu processo produtivo e a sua aplicação no campo da engenharia civil. O tema da sustentabilidade é também desenvolvido no que respeita à utilização do metal zinco na construção. Posteriormente serão especificadas certas propriedades do zinco laminado. É este tipo de zinco que será aplicado na envolvente exterior de edifícios. Numa fase posterior desenvolve-se a caracterização dos diversos tipos de sistemas construtivos de fachadas, com a respetiva descrição dos sistemas. São vários os sistemas disponíveis no mercado, sendo os mais utilizados em Portugal, os sistemas de junta agrafada, sistema de encaixe e sistema Camarinha. São ainda abordados os diversos suportes deste tipo de revestimento, as patologias que podem surgir e também as vantagens e limitações do zinco como material de revestimento. Por último é apresentado o estudo de um caso concreto, baseado num projeto de um edifício de habitação multifamiliar, e serão desenvolvidos aspetos como o tipo de sistema de fachada aplicado e o seu modo de execução, para além do estudo do desempenho térmico e acústico das fachadas e o seu custo de execução.

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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics