910 resultados para Multi-Criteria Optimization


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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, Programa de Pós-Graduação em Tecnologia Ambiental e Recursos Hídricos, 2015.

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Background: The Analytic Hierarchy Process (AHP), developed by Saaty in the late 1970s, is one of the methods for multi-criteria decision making. The AHP disaggregates a complex decision problem into different hierarchical levels. The weight for each criterion and alternative are judged in pairwise comparisons and priorities are calculated by the Eigenvector method. The slowly increasing application of the AHP was the motivation for this study to explore the current state of its methodology in the healthcare context. Methods: A systematic literature review was conducted by searching the Pubmed and Web of Science databases for articles with the following keywords in their titles or abstracts: "Analytic Hierarchy Process," "Analytical Hierarchy Process," "multi-criteria decision analysis," "multiple criteria decision," "stated preference," and "pairwise comparison." In addition, we developed reporting criteria to indicate whether the authors reported important aspects and evaluated the resulting studies' reporting. Results: The systematic review resulted in 121 articles. The number of studies applying AHP has increased since 2005. Most studies were from Asia (almost 30 %), followed by the US (25.6 %). On average, the studies used 19.64 criteria throughout their hierarchical levels. Furthermore, we restricted a detailed analysis to those articles published within the last 5 years (n = 69). The mean of participants in these studies were 109, whereas we identified major differences in how the surveys were conducted. The evaluation of reporting showed that the mean of reported elements was about 6.75 out of 10. Thus, 12 out of 69 studies reported less than half of the criteria. Conclusion: The AHP has been applied inconsistently in healthcare research. A minority of studies described all the relevant aspects. Thus, the statements in this review may be biased, as they are restricted to the information available in the papers. Hence, further research is required to discover who should be interviewed and how, how inconsistent answers should be dealt with, and how the outcome and stability of the results should be presented. In addition, we need new insights to determine which target group can best handle the challenges of the AHP. © 2015 Schmidt et al.

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Electric vehicle (EV) batteries tend to have accelerated degradation due to high peak power and harsh charging/discharging cycles during acceleration and deceleration periods, particularly in urban driving conditions. An oversized energy storage system (ESS) can meet the high power demands; however, it suffers from increased size, volume and cost. In order to reduce the overall ESS size and extend battery cycle life, a battery-ultracapacitor (UC) hybrid energy storage system (HESS) has been considered as an alternative solution. In this work, we investigate the optimized configuration, design, and energy management of a battery-UC HESS. One of the major challenges in a HESS is to design an energy management controller for real-time implementation that can yield good power split performance. We present the methodologies and solutions to this problem in a battery-UC HESS with a DC-DC converter interfacing with the UC and the battery. In particular, a multi-objective optimization problem is formulated to optimize the power split in order to prolong the battery lifetime and to reduce the HESS power losses. This optimization problem is numerically solved for standard drive cycle datasets using Dynamic Programming (DP). Trained using the DP optimal results, an effective real-time implementation of the optimal power split is realized based on Neural Network (NN). This proposed online energy management controller is applied to a midsize EV model with a 360V/34kWh battery pack and a 270V/203Wh UC pack. The proposed online energy management controller effectively splits the load demand with high power efficiency and also effectively reduces the battery peak current. More importantly, a 38V-385Wh battery and a 16V-2.06Wh UC HESS hardware prototype and a real-time experiment platform has been developed. The real-time experiment results have successfully validated the real-time implementation feasibility and effectiveness of the real-time controller design for the battery-UC HESS. A battery State-of-Health (SoH) estimation model is developed as a performance metric to evaluate the battery cycle life extension effect. It is estimated that the proposed online energy management controller can extend the battery cycle life by over 60%.

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Resumen La Evaluación Múlticriterio (EMC), integra las diferentes dimensiones de una realidad en un sólo marco de análisis, para brindar un acercamiento de la gestión del recurso hídrico en los cantones Barva, Santa Bárbara y San Rafael de Heredia, con el objetivo de generar las políticas hídricas locales adecuadas. Esta estructura metodológica presenta una gran transparencia como herramienta en la toma de decisiones, identificando claramente los diferentes actores involucrados, describiendo, al mismo tiempo los problemas de gestión del recurso hídrico en la zona; a la vez que permite delimitar los conflictos sociales y mostrar diferentes posibilidades para su solución a través de compromisos y diálogo entre las partes. De éste diálogo emergen soluciones concretas, estructuradas como políticas locales hídricas, tales como: Planes de Gestión Hídrica, Inversión Pública y Privada, Coordinación Institucional, Reforma Institucional/legal. La zona presenta una atmósfera conflictiva alrededor de la gestión del agua y por tanto en la estructuración de políticas hídricas locales. Esta conflictividad ‘sectorial’(es decir por cantón) se superpone a una extraordinaria conflictividad ‘territorial’. La escasez o competencia sobre el agua se fundamenta en unas demandas crecientes que son expresión de un proceso de desarrollo urbano y turístico acelerado y desordenado.   Abstract The Evaluation Multi-criteria analysis (EMA), integrates the different dimensions of a reality in an analysis mark, to offer an approach of the administration of the hydric resources in the Heredia´s cities of Barva, Santa Bárbara and San Rafael, with the objective of generating the local adequate hydrics policies. This methodological structure presents a great transparency like tool in the taking of decisions, identifying the different involved actors clearly, describing, at the same time, the problems of administration of the hydric resources in the area; and at the same time, it allows to define the social conflicts, as showing different possibilities for their solution through commitments and dialogue among the parts. Of this dialogue concrete solutions they emerge, structured as hydrics local policies, such as: Plans of hydric management, Public and Private Investment, Institutional Coordination, Institucional/legal reforms. The area presents a conflicting atmosphere around the administration of the water and therefore in the structuring of local hydrics policies. This conflict 'sectorial' (to say for canton) it is superimposed to an extraordinary 'territorial' conflict. The shortage or competition for water are based in some growing demands that are expression of a process of quick and disordered urban and tourist development.

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O presente relatório, inserido no Mestrado em Gestão do Território, Área de Especialização em Deteção Remota e Sistemas de Informação Geográfica, lecionado pelo Departamento de Geografia e Planeamento Regional da Faculdade de Ciências Sociais e Humanas da Universidade Nova de Lisboa, pretende descrever o trabalho desenvolvido pelo mestrando enquanto estagiário no Observatório do Tráfico de Seres Humanos (OTSH). O relatório está estruturado em três capítulos distintos. No primeiro capítulo é realizada uma abordagem teórica sobre o Tráfico de Seres Humanos e a distinção entre o mesmo com o Auxílio à Imigração Ilegal. Neste, é também feita uma pequena referência à problemática dos novos fluxos de refugiados/migrantes que, no momento da realização do mesmo, constituem uma questão bastante complexa sobretudo ao nível europeu. No segundo capítulo é realizada uma caracterização da área de estudo, assim como a descrição dos dados utilizados e a metodologia aplicada no mesmo. No terceiro capítulo são apresentados os resultados finais do estudo e a cartografia de síntese que sustenta os mesmos. Para a realização deste estudo recorreu-se a uma análise multicritério em SIG para prever a localização de áreas de maior suscetibilidade de ocorrência de novos casos relativos ao crime do tráfico de seres humanos para exploração laboral na agricultura, na região do Alentejo (distritos de Beja, Évora e Portalegre), através do recurso a dados estatísticos disponibilizados tanto pelo OTSH, como por outras entidades. A metodologia apresentada integra um SIG baseado num modelo raster com o Analytical Hierarchy Process (AHP). Através da realização deste estudo, a importância dos SIG como ferramenta no auxílio ao processo de tomada de decisão, pôde ser testada, conjuntamente com o processo metodológico AHP, através dos resultados apresentados. Com um possível desenvolvimento deste modelo analítico, pretende-se que o mesmo seja adaptável a outras regiões e em última instância, outros tipos de exploração e/ou tráfico.

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The study of Quality of Life (Qol) has been conducted on various scales throughout the years with focus on assessing overall quality of living amongst citizens. The main focus in these studies have been on economic factors, with the purpose of creating a Quality of Life Index (QLI).When it comes down to narrowing the focus to the environment and factors like Urban Green Spaces (UGS) and air quality the topic gets more focused on pointing out how each alternative meets this certain criteria. With the benefits of UGS and a healthy environment in focus a new Environmental Quality of Life Index (EQLI) will be proposed by incorporating Multi Criteria Analysis (MCA) and Geographical Information Systems (GIS). Working with MCA on complex environmental problems and incorporating it with GIS is a challenging but rewarding task, and has proven to be an efficient approach among environmental scientists. Background information on three MCA methods will be shown: Analytical Hierarchy Process (AHP), Regime Analysis and PROMETHEE. A survey based on a previous study conducted on the status of UGS within European cities was sent to 18 municipalities in the study area. The survey consists of evaluating the current status of UGS as well as planning and management of UGS with in municipalities for the purpose of getting criteria material for the selected MCA method. The current situation of UGS is assessed with use of GIS software and change detection is done on a 10 year period using NDVI index for comparison purposes to one of the criteria in the MCA. To add to the criteria, interpolation of nitrogen dioxide levels was performed with ordinary kriging and the results transformed into indicator values. The final outcome is an EQLI map with indicators of environmentally attractive municipalities with ranking based on predefinedMCA criteria using PROMETHEE I pairwise comparison and PROMETHEE II complete ranking of alternatives. The proposed methodology is applied to Lisbon’s Metropolitan Area, Portugal.

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Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL

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Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

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To analyze the characteristics and predict the dynamic behaviors of complex systems over time, comprehensive research to enable the development of systems that can intelligently adapt to the evolving conditions and infer new knowledge with algorithms that are not predesigned is crucially needed. This dissertation research studies the integration of the techniques and methodologies resulted from the fields of pattern recognition, intelligent agents, artificial immune systems, and distributed computing platforms, to create technologies that can more accurately describe and control the dynamics of real-world complex systems. The need for such technologies is emerging in manufacturing, transportation, hazard mitigation, weather and climate prediction, homeland security, and emergency response. Motivated by the ability of mobile agents to dynamically incorporate additional computational and control algorithms into executing applications, mobile agent technology is employed in this research for the adaptive sensing and monitoring in a wireless sensor network. Mobile agents are software components that can travel from one computing platform to another in a network and carry programs and data states that are needed for performing the assigned tasks. To support the generation, migration, communication, and management of mobile monitoring agents, an embeddable mobile agent system (Mobile-C) is integrated with sensor nodes. Mobile monitoring agents visit distributed sensor nodes, read real-time sensor data, and perform anomaly detection using the equipped pattern recognition algorithms. The optimal control of agents is achieved by mimicking the adaptive immune response and the application of multi-objective optimization algorithms. The mobile agent approach provides potential to reduce the communication load and energy consumption in monitoring networks. The major research work of this dissertation project includes: (1) studying effective feature extraction methods for time series measurement data; (2) investigating the impact of the feature extraction methods and dissimilarity measures on the performance of pattern recognition; (3) researching the effects of environmental factors on the performance of pattern recognition; (4) integrating an embeddable mobile agent system with wireless sensor nodes; (5) optimizing agent generation and distribution using artificial immune system concept and multi-objective algorithms; (6) applying mobile agent technology and pattern recognition algorithms for adaptive structural health monitoring and driving cycle pattern recognition; (7) developing a web-based monitoring network to enable the visualization and analysis of real-time sensor data remotely. Techniques and algorithms developed in this dissertation project will contribute to research advances in networked distributed systems operating under changing environments.

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If marine management policies and actions are to achieve long-term sustainable use and management of the marine environment and its resources, they need to be informed by data giving the spatial distribution of seafloor habitats over large areas. Broad-scale seafloor habitat mapping is an approachwhich has the benefit of producing maps covering large extents at a reasonable cost. This approach was first investigated by Roff et al. (2003), who, acknowledging that benthic communities are strongly influenced by the physical characteristics of the seafloor, proposed overlaying mapped physical variables using a geographic information system (GIS) to produce an integrated map of the physical characteristics of the seafloor. In Europe the method was adapted to the marine section of the EUNIS (European Nature Information System) classification of habitat types under the MESH project, andwas applied at an operational level in 2011 under the EUSeaMap project. The present study compiled GIS layers for fundamental physical parameters in the northeast Atlantic, including (i) bathymetry, (ii) substrate type, (iii) light penetration depth and (iv) exposure to near-seafloor currents andwave action. Based on analyses of biological occurrences, significant thresholds were fine-tuned for each of the abiotic layers and later used in multi-criteria raster algebra for the integration of the layers into a seafloor habitat map. The final result was a harmonised broad-scale seafloor habitat map with a 250 m pixel size covering four extensive areas, i.e. Ireland, the Bay of Biscay, the Iberian Peninsula and the Azores. The map provided the first comprehensive perception of habitat spatial distribution for the Iberian Peninsula and the Azores, and fed into the initiative for a pan- European map initiated by the EUSeaMap project for Baltic, North, Celtic and Mediterranean seas.

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The success of regional development policies depends on the homogeneity of the territorial units. This paper aims to propose a framework for obtaining homogenous territorial clusters based on a Pareto frontier considering multiple criteria related to territories’ endogenous resources, economic profile and socio-cultural features. This framework is developed in two phases. First, the criteria correlated with development at the territorial unit level are determined through statistical and econometric methods. Then, a multi-criteria approach is developed to allocate each territorial unit (parishes) to a territorial agglomerate, according to the Pareto frontier established.

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Este artículo describe la puesta en funcionamiento de una herramienta de información geográfica para la gestión y planificación de recursos hídricos de Cataluña desarrollada mediante plataformas OpenSource. Esta herramienta ha de permitir responder a sucesos extremos como la sequía, facilitando de manera intuitiva y rápida elementos de  evaluación y toma de decisiones. Este Sistema de Información Geográfica (SIG) de gestión de los recursos hídricos se ha  desarrollado para obtener resultados a medida del cliente. Su interfaz ágil y sencilla, su capacidad multiusuario, su alto  rendimiento y escalabilidad y la ausencia de costes de licencia hacen que, con una inversión limitada, se obtenga una amortización muy rápida. Cabe destacar la automatización de procesos sistemáticos, geoprocesos y análisis multicriterio definidos por el cliente, que le permiten ahorrar tiempo y recursos, así como aumentar la productividad.Palabras clave: Sistema de Información Geográfica (SIG), acceso abierto, gestión, agua, automatizaciónAbstractThis article describes the implementation of a geographical information tool developed on an OpenSource platform for the management and planning of water resources in Catalonia. This Geographic Information System (GIS) is designed to deliver fast and intuitive evaluation and decision making criteria in response to extreme events, such as drought. Its strong customization, user friendliness, multiuser capability, performance and scalability, together with its license-free condition, allow for an extremely fast return on investment. The embedded automation of user-defined systemic processes, geo-processes and multi-criteria analyses provide significant time and resource savings and productivity Key Words: Geographic Information System (GIS), Open Source, water supply management, automation

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La experiencia en la gestión de cuencas, en particular en su aspecto hídrico-social, indica que el problema surge por causalidad recíproca de distintos factores biológicos y socioeconómicos, ligados a una gestión del desarrollo, que por lo común, no atiende los riesgos que crea. La gestión efectiva de los recursos hídricos y bióticos involucrados suele ignorar el conflicto que. en términos sociales, traen consigo los usos no sustentables. Por tanto, una gestión alternativa exige un enfoque integral, que busque relacionar valores sociales (no  únicamente económicos) con criterios ecológicos y con otros parámetros diversos.La integral idad de la gestión de cuencas depende de que las decisiones estén sujetas tanto a sistemas de planificación territorial, con la perspectiva abierta sobre los ecosistemas boscosos (protección de cuencas, control de erosión, ciclo del carbono, recreación, etc.) como a sistemas interdependientes de preferencias o toma de decisiones sociales.Lo anterior no se puede evaluar eficientemente con las técnicas convencionales de valoración, ni con las herramientas de la economía ambiental y de recursos naturales para países en desarrollo. Si bien esas técnicas son útiles en la administración de algunos recursos estratégicos. no son suficientes cuando se trata de valorar ambientes donde se debe enfrentar limitaciones en términos de indeterminación, incertidumbre, indivisibilidad, racionalidades sujetas a decisiones colectivas e individuales o a cuestiones de distribución socioecológica.El diseño metodológico aquí presentado ha permitido identificar los diferentes actores involucrados, describiendo, al mismo tiempo, los problemas de gestión que enfrentan y ha pennitido delimitar los conflictos sociales y mostrar diferentes posibilidades para su solución por medio de compromisos, cooperación y diálogo entre las panes, dando oportunidad que emergieran soluciones para el manejo integral de la subcuenca del no Viruta.Abstract:The experience in the administration of basins, in particular in their social-hydric aspect, it indicates that thc problem anses for reciprocal causation of different biological and socioeconomic factors, bound toan administration of dic development thai in general doesn’t assist dic risks thai shelhe believes. The effectivc administration of the hydrics resources and involved biotic usually ignore dic conflict that, in social terms. she/he brings 1 gel the non sustainablc uses. Therefore. an alternative administration demands an integral focus thai looks for to relate social values (nol only economic) to ecological approaches and other diverse parameters.The composedly of dic basin administration depends thai the decisions are subject to systems of territorial planning. with dic open perspective on the wooded ecosystems (basin protection, erosion control. cycle of the carbon. recreation, etc.) as much as Lo intcrdcpendeni systems of preferences or taking of social decisions.The above-mentioned you can nol evaluate efficiendy with the conventional techniques of valuacion, neithcr with the tools of the environmental economy and of natural resources for countries in development. Although those techniques are useful in ihe administration of sorne strategic resources. they are fol enough when it is to value atmospheres where it should be faced limitations in indetermination terms. uncertainty, indivisibility, rationalities subject to collecuve and individual decisions. or to questions of partner-ecological distribution.The mcthodological design here prescnted it has allowcd lo ideniify. the different involved actors, describing, al the same time, dic administration problems that face and it has allowed to define the social contlicts and to show different possibilities for dic their solution through comrnitments, cooperation and dialogue arnong dic paris. giving opportunity thai solutions emerged for the integral handling of the Vinila river basin.

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Against a backdrop of rapidly increasing worldwide population and growing energy demand, the development of renewable energy technologies has become of primary importance in the effort to reduce greenhouse gas emissions. However, it is often technically and economically infeasible to transport discontinuous renewable electricity for long distances to the shore. Another shortcoming of non-programmable renewable power is its integration into the onshore grid without affecting the dispatching process. On the other hand, the offshore oil & gas industry is striving to reduce overall carbon footprint from onsite power generators and limiting large expenses associated to carrying electricity from remote offshore facilities. Furthermore, the increased complexity and expansion towards challenging areas of offshore hydrocarbons operations call for higher attention to safety and environmental protection issues from major accident hazards. Innovative hybrid energy systems, as Power-to-Gas (P2G), Power-to-Liquid (P2L) and Gas-to-Power (G2P) options, implemented at offshore locations, would offer the opportunity to overcome challenges of both renewable and oil & gas sectors. This study aims at the development of systematic methodologies based on proper sustainability and safety performance indicators supporting the choice of P2G, P2L and G2P hybrid energy options for offshore green projects in early design phases. An in-depth analysis of the different offshore hybrid strategies was performed. The literature reviews on existing methods proposing metrics to assess sustainability of hybrid energy systems, inherent safety of process routes in conceptual design stage and environmental protection of installations from oil and chemical accidental spills were carried out. To fill the gaps, a suite of specific decision-making methodologies was developed, based on representative multi-criteria indicators addressing technical, economic, environmental and societal aspects of alternative options. A set of five case-studies was defined, covering different offshore scenarios of concern, to provide an assessment of the effectiveness and value of the developed tools.

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We address the problem of automotive cybersecurity from the point of view of Threat Analysis and Risk Assessment (TARA). The central question that motivates the thesis is the one about the acceptability of risk, which is vital in taking a decision about the implementation of cybersecurity solutions. For this purpose, we develop a quantitative framework in which we take in input the results of risk assessment and define measures of various facets of a possible risk response; we then exploit the natural presence of trade-offs (cost versus effectiveness) to formulate the problem as a multi-objective optimization. Finally, we develop a stochastic model of the future evolution of the risk factors, by means of Markov chains; we adapt the formulations of the optimization problems to this non-deterministic context. The thesis is the result of a collaboration with the Vehicle Electrification division of Marelli, in particular with the Cybersecurity team based in Bologna; this allowed us to consider a particular instance of the problem, deriving from a real TARA, in order to test both the deterministic and the stochastic framework in a real world application. The collaboration also explains why in the work we often assume the point of view of a tier-1 supplier; however, the analyses performed can be adapted to any other level of the supply chain.