969 resultados para Autonomous Vehicle Path Planning


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In recent decades, all over the world, competition in the electric power sector has deeply changed the way this sector’s agents play their roles. In most countries, electric process deregulation was conducted in stages, beginning with the clients of higher voltage levels and with larger electricity consumption, and later extended to all electrical consumers. The sector liberalization and the operation of competitive electricity markets were expected to lower prices and improve quality of service, leading to greater consumer satisfaction. Transmission and distribution remain noncompetitive business areas, due to the large infrastructure investments required. However, the industry has yet to clearly establish the best business model for transmission in a competitive environment. After generation, the electricity needs to be delivered to the electrical system nodes where demand requires it, taking into consideration transmission constraints and electrical losses. If the amount of power flowing through a certain line is close to or surpasses the safety limits, then cheap but distant generation might have to be replaced by more expensive closer generation to reduce the exceeded power flows. In a congested area, the optimal price of electricity rises to the marginal cost of the local generation or to the level needed to ration demand to the amount of available electricity. Even without congestion, some power will be lost in the transmission system through heat dissipation, so prices reflect that it is more expensive to supply electricity at the far end of a heavily loaded line than close to an electric power generation. Locational marginal pricing (LMP), resulting from bidding competition, represents electrical and economical values at nodes or in areas that may provide economical indicator signals to the market agents. This article proposes a data-mining-based methodology that helps characterize zonal prices in real power transmission networks. To test our methodology, we used an LMP database from the California Independent System Operator for 2009 to identify economical zones. (CAISO is a nonprofit public benefit corporation charged with operating the majority of California’s high-voltage wholesale power grid.) To group the buses into typical classes that represent a set of buses with the approximate LMP value, we used two-step and k-means clustering algorithms. By analyzing the various LMP components, our goal was to extract knowledge to support the ISO in investment and network-expansion planning.

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Important research effort has been devoted to the topic of optimal planning of distribution systems. The non linear nature of the system, the need to consider a large number of scenarios and the increasing necessity to deal with uncertainties make optimal planning in distribution systems a difficult task. Heuristic techniques approaches have been proposed to deal with these issues, overcoming some of the inherent difficulties of classic methodologies. This paper considers several methodologies used to address planning problems of electrical power distribution networks, namely mixedinteger linear programming (MILP), ant colony algorithms (AC), genetic algorithms (GA), tabu search (TS), branch exchange (BE), simulated annealing (SA) and the Bender´s decomposition deterministic non-linear optimization technique (BD). Adequacy of theses techniques to deal with uncertainties is discussed. The behaviour of each optimization technique is compared from the point of view of the obtained solution and of the methodology performance. The paper presents results of the application of these optimization techniques to a real case of a 10-kV electrical distribution system with 201 nodes that feeds an urban area.

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Will the existing means in Radiotherapy respond to the needs of the potential user population in 2014 for Lisbon and Santarém districts? Number of treatment units? Number of Radiotherapy Technologists? Temporal variations of the dimension and age structure of the populations: Coastal areas/Interior areas, Urban areas/Rural areas. Temporal variations in the incidence of several types of cancer. Overall objectives: evaluate of the necessities of Radiotherapy for Lisbon and Santarém districts in 2014 and elaboration of proposals that aim the access/use for the potential user population.

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In this paper we present a mobile recommendation and planning system, named PSiS Mobile. It is designed to provide effective support during a tourist visit through context-aware information and recommendations about points of interest, exploiting tourist preferences and context. Designing a tool like this brings several challenges that must be addressed. We discuss how these challenges have been overcame, present the overall system architecture, since this mobile application extends the PSiS project website, and the mobile application architecture.

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Enquadramento: O VIH/Sida exige uma ação direcionada na vertente da prevenção, cujo suporte integra a transmissão de conhecimentos promotores da adoção e manutenção de comportamentos seguros, em conformidade com as características sociais e culturais dos indivíduos. Objetivos: Validar, para a população do Sudão do Sul, a Escala de Conhecimentos sobre VIH/Sida, The HIV Knowledge Questionnaire: HIV-KQ-45, de Carey et al. (1997); analisar de que forma as variáveis sociodemográficas influenciam os conhecimentos sobre VIH/Sida, dos cidadãos de Mapuordit Sudão do Sul; verificar se a frequência de formação sobre VIH/Sida influencia o seu nível de conhecimentos. Metodologia: Estudo quantitativo, descritivo-analítico e transversal, com 232 clientes do Mary Immaculate de Mapuordit Hospital. Foi utilizado um Questionário de caracterização sociodemográfica e do contexto de formação sobre o VIH/Sida, e o HIV Knowledge Questionnaire (HVI-K-Q) de Carey, Morrison-Beedy e Johnson (1997). Resultados: Amostra é maioritariamente masculina (74.6%), com uma média de idade 22,83 (±5.793 anos). A análise fatorial confirmatória do HIV-K-Q permitiu apurar 5 fatores, cujos valores médios mais significativos foram nos fatores preconceitos/medos (média=80.60%), conhecimentos sobre os comportamentos de risco (média=76.58%) e vias de transmissão (média=70.36%). Os sudaneses pontuaram maioritariamente com razoáveis conhecimentos sobre a Sida (média=68.08%). As mulheres, os participantes mais velhos, com companheiro(a), mais escolarizados, profissionalmente ativos, a distar do hospital =<20 Km, deslocando-se num veículo não motorizado e com diagnóstico de VIH relataram mais conhecimentos sobre a Sida. Os participantes com informação sobre a prevenção do VIH/Sida e frequência em workshop na área demonstraram melhores conhecimentos. Revelaram-se preditivas dos conhecimentos acerca da doença as habilitações literárias (β=0.32) e o diagnóstico de VIH/Sida (β=0.14) revelou-se preditor dos conhecimentos sobre os comportamentos de risco. Conclusão: As casuísticas significativas do VIH/Sida justificam considerar as habilitações literárias e a presença de diagnóstico VIH/Sida como variáveis a avaliar previamente ao planeamento estratégico das ações de educação para a prevenção do VIH/Sida no Sudão do Sul. Palavras-chave: Conhecimentos; VIH/Sida; Sudão do Sul.

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The purpose of this paper was to introduce the symbolic formalism based on kneading theory, which allows us to study the renormalization of non-autonomous periodic dynamical systems.

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In the present paper we analyzed the behavior of firms in the construction and manufacturing sectors, located in the region of Vale do Sousa, in the north of Portugal. From the literature, even existing some disagreements, it is possible to conclude that planning is crucial for firms survival and growth. Cooperation is another aspect that the literature presents as an important factor for firms sustainability. It also plays a major role in competition, since firms are adopting coopetition strategies. By studying a sample of 251 firms, it was possible to realize, that the majority started their business without a formal planning, and they keep going without using it. In cooperation aspects, there is a lack of cooperation. It was possible to verify, that existing cooperation has some evidence but at a vertical level. These vertical relations were also identified in stakeholder’s involvement.

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Electric vehicles (EV) offer a great potential to address the integration of renewable energy sources (RES) in the power grid, and thus reduce the dependence on oil as well as the greenhouse gases (GHG) emissions. The high share of wind energy in the Portuguese energy mix expected for 2020 can led to eventual curtailment, especially during the winter when high levels of hydro generation occur. In this paper a methodology based on a unit commitment and economic dispatch is implemented, and a hydro-thermal dispatch is performed in order to evaluate the impact of the EVs integration into the grid. Results show that the considered 10 % penetration of EVs in the Portuguese fleet would increase load in 3 % and would not integrate a significant amount of wind energy because curtailment is already reduced in the absence of EVs. According to the results, the EV is charged mostly with thermal generation and the associated emissions are much higher than if they were calculated based on the generation mix.

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OBJECTIVE: To assess personal autonomy of long-stay psychiatric inpatients, to identify those patients who could be discharged and to evaluate the impact of sociodemographic variables, social functioning, and physical disabilities on their autonomy was also assessed. METHODS: A total of 584 long-stay individuals of a psychiatric hospital (96% of the hospital population) in Southern Brazil was assessed between July and August 2002. The following instruments, adapted to the Brazilian reality, were used: independent living skills survey, social behavioral schedule, and questionnaire for assessing physical disability. RESULTS: Patients showed severe impairment of their personal autonomy, especially concerning money management, work-related skills and leisure, food preparation, and use of transportation. Autonomy deterioration was associated with length of stay (OR=1.02), greater physical disability (OR=1.54; p=0.01), and male gender (OR=3.11; p<0.001). The risk estimate of autonomy deterioration was 23 times greater among those individuals with severe impairment of social functioning (95% CI: 10.67-49.24). CONCLUSIONS: In-patients studied showed serious impairment of autonomy. While planning these patients' discharge their deficits should be taken into consideration. Assessment of patients' ability to function and to be autonomous helps in identifying their needs for care and to evaluate their actual possibilities of social reinsertion.

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Pós-graduação em Ciência da Computação - IBILCE

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Several field methodologies, analytical measures and theoretical patterns have been explored for conservation planning for arthropods in native forests of the Azores archipelago. Here, the outcomes are assembled to make recommendations on practical strategies to assess arthropod diversity and to select and manage protected native forests in the Azores. Suggestions are made on how to apply similar plans for conservation of other plant and animal groups in these forests. Potential threats to the Azorean native forest are described and measures to minimize them are proposed. Future studies are also suggested that would improve the present knowledge of arthropod diversity and distribution in Azorean native forests and could assist in the identification of suitable conservation strategies.

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This paper presents a proposal for an automatic vehicle detection and classification (AVDC) system. The proposed AVDC should classify vehicles accordingly to the Portuguese legislation (vehicle height over the first axel and number of axels), and should also support profile based classification. The AVDC should also fulfill the needs of the Portuguese motorway operator, Brisa. For the classification based on the profile we propose:he use of Eigenprofiles, a technique based on Principal Components Analysis. The system should also support multi-lane free flow for future integration in this kind of environments.

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Tese de Doutoramento, Ciências do Mar (Biologia Marinha)

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This work aims at investigating the impact of treating breast cancer using different radiation therapy (RT) techniques – forwardly-planned intensity-modulated, f-IMRT, inversely-planned IMRT and dynamic conformal arc (DCART) RT – and their effects on the whole-breast irradiation and in the undesirable irradiation of the surrounding healthy tissues. Two algorithms of iPlan BrainLAB treatment planning system were compared: Pencil Beam Convolution (PBC) and commercial Monte Carlo (iMC). Seven left-sided breast patients submitted to breast-conserving surgery were enrolled in the study. For each patient, four RT techniques – f-IMRT, IMRT using 2-fields and 5-fields (IMRT2 and IMRT5, respectively) and DCART – were applied. The dose distributions in the planned target volume (PTV) and the dose to the organs at risk (OAR) were compared analyzing dose–volume histograms; further statistical analysis was performed using IBM SPSS v20 software. For PBC, all techniques provided adequate coverage of the PTV. However, statistically significant dose differences were observed between the techniques, in the PTV, OAR and also in the pattern of dose distribution spreading into normal tissues. IMRT5 and DCART spread low doses into greater volumes of normal tissue, right breast, right lung and heart than tangential techniques. However, IMRT5 plans improved distributions for the PTV, exhibiting better conformity and homogeneity in target and reduced high dose percentages in ipsilateral OAR. DCART did not present advantages over any of the techniques investigated. Differences were also found comparing the calculation algorithms: PBC estimated higher doses for the PTV, ipsilateral lung and heart than the iMC algorithm predicted.

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Mestrado em Engenharia Electrotécnica e de Computadores. Área de Especialização em Sistemas Autónomos