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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Otimização Multiobjetivo em Problemas de Delineamento de Experimentos / Multiobjective Optimization in DOE Problems

Rodrigues, Douglas Miranda [UNESP] 10 October 2016 (has links)
Submitted by DOUGLAS MIRANDA RODRIGUES null (douglasnet@gmail.com) on 2016-10-20T13:35:28Z No. of bitstreams: 1 Dissertação - Douglas Miranda Rodrigues.pdf: 8525562 bytes, checksum: de3f28242f3d17929bb0eb8ddc912f55 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-10-26T18:00:28Z (GMT) No. of bitstreams: 1 rodrigues_dm_me_guara.pdf: 8525562 bytes, checksum: de3f28242f3d17929bb0eb8ddc912f55 (MD5) / Made available in DSpace on 2016-10-26T18:00:28Z (GMT). No. of bitstreams: 1 rodrigues_dm_me_guara.pdf: 8525562 bytes, checksum: de3f28242f3d17929bb0eb8ddc912f55 (MD5) Previous issue date: 2016-10-10 / Em diversas áreas de trabalho, da Engenharia à Economia, os problemas se apresentam como sendo multiobjetivos, característica que torna complexa a tomada de decisão. Geralmente, estes objetivos são conflitantes e faz-se necessário o uso de técnicas de otimização para a obtenção de melhores resultados. Na presente dissertação serão estudados alguns métodos para a resolução destes problemas, com o objetivo de aplicar métodos de aglutinação em problemas de projetos de experimentos com múltiplas respostas. Deste modo, inicialmente foi realizada uma análise bibliométrica sobre os diferentes métodos utilizados para a resolução destes problemas. A partir disto, foi desenvolvida uma nova abordagem, utilizando a Programação por Compromisso (Compromise Programming – CP) e a Programação por Metas (Goal Programming – GP), bem como diferentes algoritmos (Gradiente Reduzido Generalizado – GRG e a metaheurística do software Optquest) que são usualmente adotados, com comparação de resultados e análise. De modo geral, esta nova proposta apresentou resultados melhores em relação à abordagem tradicional (desirability), qualificando este procedimento como uma alternativa na otimização de múltiplas respostas. / In many areas, from Engineering to Economics, problems present themselves as multiobjective, which makes a decision-making process complex. Generally, these are conflicting objectives, and optimization techniques are necessary to achieve better results. This paper applies agglutination methods in classical problems of design of experiments with multiple responses. A bibliometric analysis was made, and a new approach was developed, using Compromise Programming – CP and Goal Programming – GP, as well as two different algorithms (Generalized Reduced Gradient – GRG and Optquest’s software metaheuristics) with results comparison and analysis. The new proposal presented better results when compared to the traditional approach (desirability), qualifying this procedure as an alternative in multiple responses optimization.
2

Otimização Multiobjetivo em Problemas de Delineamento de Experimentos /

Rodrigues, Douglas Miranda January 2016 (has links)
Orientador: Fernando Augusto da Silva Marins / Resumo: Em diversas áreas de trabalho, da Engenharia à Economia, os problemas se apresentam como sendo multiobjetivos, característica que torna complexa a tomada de decisão. Geralmente, estes objetivos são conflitantes e faz-se necessário o uso de técnicas de otimização para a obtenção de melhores resultados. Na presente dissertação serão estudados alguns métodos para a resolução destes problemas, com o objetivo de aplicar métodos de aglutinação em problemas de projetos de experimentos com múltiplas respostas. Deste modo, inicialmente foi realizada uma análise bibliométrica sobre os diferentes métodos utilizados para a resolução destes problemas. A partir disto, foi desenvolvida uma nova abordagem, utilizando a Programação por Compromisso (Compromise Programming – CP) e a Programação por Metas (Goal Programming – GP), bem como diferentes algoritmos (Gradiente Reduzido Generalizado – GRG e a metaheurística do software Optquest) que são usualmente adotados, com comparação de resultados e análise. De modo geral, esta nova proposta apresentou resultados melhores em relação à abordagem tradicional (desirability), qualificando este procedimento como uma alternativa na otimização de múltiplas respostas. / Mestre
3

Υποδείγματα μαθηματικού προγραμματισμού για το σχεδιασμό του ωρολογίου προγράμματος ενός εκπαιδευτικού ιδρύματος

Δήμου, Ελένη 27 October 2008 (has links)
Η παρούσα μεταπτυχιακή εργασία πραγματεύεται το πρόβλημα του σχεδιασμού του ωρολογίου προγράμματος μαθημάτων ενός εκπαιδευτικού ιδρύματος και πιο συγκεκριμένα ενός πανεπιστημίου. Λόγω της πολυπλοκότητας και της ύπαρξης πολυάριθμων μεταβλητών και παραμέτρων το πρόβλημα ανήκει στην κατηγορία των NP-complete προβλημάτων, γεγονός που κάνει την εξεύρεση της βέλτιστης λύσης μία πολύ δύσκολη υπόθεση. Η βιβλιογραφική ανασκόπηση έδειξε ότι έχουν προταθεί και εφαρμόζονται πολλές και διαφορετικές μεθοδολογίες επίλυσης του προβλήματος. Οι τεχνικές προέρχονται από πολλούς και διαφορετικούς τομείς όπως για παράδειγμα το μαθηματικό προγραμματικό, τον ακέραιο γραμμικό προγραμματισμό, τις μετα-ευρετικές μεθόδους, αλλά και από τον χώρο της Τεχνητής Νοημοσύνης. Η μέθοδος επίλυσης, που προτείνεται από την παρούσα εργασία, είναι η πολυκριτηριακή ανάλυση βασιζόμενη στον συναινετικό προγραμματισμό (compromise programming). Η εφαρμογή της μεθόδου σε δεδομένα προβλημάτων ωρολογίου προγραμματισμού, είχε πολύ ικανοποιητικά αποτελέσματα, καθώς προεκύψαν ποιοτικά ωρολόγια προγράμματα, που ικανοποιούσαν όλους τους περιορισμούς. / The timetabling problem constists in scheduling a sequence of lectures between teachers and students in a prefixed period of time, satisfying a set of constraints of various type. Due to the complexity and the existence of many variables and parameters, the problem belongs in the category of NP-complete problems, fact that makes the discovery of an optimal solution, a very difficult affair. The bibliographic search, showed that have been proposed and are applied many and different solving techniques, which are based on Mathematical programming (Integer Linear Programming), on Graph Colouring, on Meta-Heuristics Methods, on Multicriteria approaches, on Case-based approaches, but also belonging to Artificial Intelligence. In this paper, the multicriteria approach based on Compromise programming is suggested. The application of technique in timetable data of an educational institute, had very good results, and provided qualitative timetables, satisfying all constraints.
4

Scoring rules -- pokročilé hlasovací systémy s pořadím kandidátů / Scoring rules - ranked advanced voting systems

Zýková, Petra January 2017 (has links)
This thesis deals with ranked advanced voting systems. The aim is to determine the overall winner and the ranking of candidates based on voters' preferences. The thesis utilises basic voting systems - plurality rules, lexicographical and Borda's method - as well as advanced voting systems with the application of DEA models, specifically DEA/AR model, DEA/AR exclusion model (including variations with penalties), and Llamazares-Peňa model. Compromise programming is used to obtain common vector of weights. The models and their use are demonstrated on Formula One Grand Prix results from season 2016. Formula One World Drivers' Championship and Formula One World Constructors' Championship are being investigated.
5

Novas estratégias para a otimização em problemas com múltiplas respostas: um estudo no tratamento de efluentes fenólicos / New strategies for optimizing multiple responses: a study in the treatment of phenolic wastewater

Freitas, Ana Paula Barbosa Rodrigues de [UNESP] 05 July 2016 (has links)
Submitted by ANA PAULA BARBOSA RODRIGUES DE FREITAS null (anapaula_b22@yahoo.com.br) on 2016-08-02T23:34:18Z No. of bitstreams: 1 Tese Doutorado - Ana Paula Barbosa Rodrigues de Freitas Final.pdf: 2474072 bytes, checksum: 89629b7295e607d20073a144561101a1 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-05T13:02:51Z (GMT) No. of bitstreams: 1 freitas_apbr_dr_guara.pdf: 2474072 bytes, checksum: 89629b7295e607d20073a144561101a1 (MD5) / Made available in DSpace on 2016-08-05T13:02:51Z (GMT). No. of bitstreams: 1 freitas_apbr_dr_guara.pdf: 2474072 bytes, checksum: 89629b7295e607d20073a144561101a1 (MD5) Previous issue date: 2016-07-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi a aplicação de técnicas de otimização envolvendo múltiplas respostas em problemas da área ambiental, mais especificamente no tratamento de efluentes fenólicos. O efluente é oriundo da Brasquip Ambiental, que é uma empresa de engenharia e prestação de serviços. A otimização foi realizada pelos métodos GRG, Desirability, Simulação Monte Carlo Estocástica. Neste trabalho o efluente foi degradado por meio de processos alternativos; os Processos Oxidativos Avançados. No estudo desenvolvido, as variáveis respostas utilizadas foram: % remoção de Carbono Orgânico Total, Demanda Química de Oxigênio e Fenóis Totais. A função Compromisse Programming foi aplicada como um método de aglutinação, sendo também, comparada com os resultados obtidos pelos métodos Desirabilty. As variáveis de decisão, ou variáveis entrada, obtidas na Simulação Monte Carlo Estocástico, nos métodos Desirability e GRG foram validados experimentalmente. Logo, as remoções obtidas para o Arranjo Ortogonal de Taguchi e do Método de Superfície de Resposta (MSR) foram significativas para as variáveis respostas obtidas, mas a remoção de fenóis totais foi a mais significativa. No estudo estocástico, os valores experimentais obtidos do Taguchi e do MSR também apresentaram-se relevantes para a mineralização do efluente fenólico. Os resultados obtidos experimentalmente da Simulação Monte Carlo Estocástica apresentaram próximos dos obtidos pelo software, sendo que o algoritmo utilizado foi o Optquest. A função CP apresentou valores relevantes para a degradação do efluente, sendo que para este trabalho a Simulação Monte Carlo Estocástica e GRG foram mais significativos se comparado com método Desirability. / The objective of this work was the application of multiple optimization techniques involving responses from environmental problems, specifically in the treatment of phenolic wastewater. The effluent comes from the Environmental Brasquip, which is an engineering company and services. The optimization was performed by the methods GRG, Desirability, Monte Carlo Simulation Stochastic. In this work the effluent was degraded by alternative processes; the Advanced Oxidation Processes. In the study, the variables used responses were:% removal of Total Organic Carbon, Chemical Oxygen Demand and Total Phenols. The Compromisse Programming function has been applied as an agglutination method, also being compared with the results obtained by Desirabilty methods. The decision variables, or variables input obtained in Monte Carlo simulation Stochastic in Desirability methods and GRG were validated experimentally. So removals obtained for Orthogonal Arrangement Taguchi and Response Surface Method (RSM) were significant to the variable responses obtained, but the removal of total phenols was the most significant. In stochastic study, the experimental values and the Taguchi MSR also showed themselves relevant for the mineralization of the phenolic effluent. The experimental results of Monte Carlo Simulation of Stochastic presented near obtained by software, whereas the algorithm used was OptQuest. The CP function showed significant values for degradation of effluent, and for this work to Monte Carlo Simulation Stochastic and GRG were more significant compared with Desirability method.
6

A Hydroclimatological Change Detection and Attribution Study over India using CMIP5 Models

Pattanayak, Sonali January 2015 (has links) (PDF)
As a result of increase in global average surface temperature, abnormalities in different hydroclimatic components such as evapotranspiration, stream flow and precipitation have been experienced. So investigation has to be carried out to assess the hidden abnormality subsisting in the hydroclimatological time series in the form of trend. This thesis broadly consists of following four parts. The first part comprises of a detailed review of various trend detection approaches. Approaches incorporating the effect of serial correlation for trend detection and interesting developments concerning various non parametric approaches are focused explicitly. Recent trends in annual, monthly, and seasonl (winter, pre-monsoon, monsoon and post-monsoon) Tmax and Tmin have been analyzed considering three time slots viz. 1901-2003, 1948-2003 and 1970-2003. For this purpose, time series of Tmax and Tmin of India as a whole and for seven homogeneous regions, viz. Western Himalaya (WH), Northwest (NW), Northeast (NE), North Central (NC), East coast (EC), West coast (WC) and Interior Peninsula (IP) were originally considered. During the last three decades significant upward trend in Tmin is found to be present in all regions considered either at annual or seasonal level. Sequential Mann Kendall test revealed that most of the significant upward trends both in Tmax and Tmin began after 1970. The second part discusses about numerous climate models from both Coupled Model Inter comparison Project-5 and 3 (i.e. CMIP5, CMIP3) and their skills in simulating Indian climate and assessing their performance using various evaluation measures. Performances of climate models were evaluated for whole of India and over all the individual grid points covering India. The newly defined metric symbolized as Skill_All is an intersection of the three metrics i.e. Skill_r, Skill_s and Skill_rmse, is used for overall model evaluation analysis. A notable enhancement of Skill_All for CMIP5 over CMIP3 was found. After overall model evaluation study, Compromise Programming, a distance based decision making technique, was employed to rank the GCMs gridwise. Entropy method was employed to obtain weights of the chosen indicators. Group decision making methodology was used to arrive at a consensus based on the ranking pattern obtained by individual grid points. In the third part, a detailed detection and attribution (D&A) analysis is performed to determine the causes of changes in seasonal Tmax and Tmin during the period 1950-2005. This formal D&A exercise helps in providing better insight (than trend detection analysis) into the nature of the observed seasonal temperature changes. It was noticed that the emergence of observed trend was more pronounced in Tmin compared to Tmax. Although observed changes were not solely associated with one specific causative factor, most of the changes in Tmin are above the bounds of natural internal climate variability. Finally in the fourth part, to understand the climate change impact on the hydrological cycle, a spatiotemporal change detection study of potential evapotranspiration (PET) along with Tmax and Tmin over India has been performed. Climatology patterns for PET confirmed a greater PET rate during the month of March, April, May and June. A significant increasing trend in both Tmax and Tmin (Tmin being more) was observed in more number of grid points compared to PET. Significant positive trends in Tmax, Tmin and PET were observed over most of the grid points in the IP region. Heterogeneities existed in the spatiotemporal variability of PET over all India. This spatio-temporal change detection study would be helpful for present and future water resources management.

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