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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.
141

AI Based Modelling and Optimization of Turning Process

Kulkarni, Ruturaj Jayant 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In this thesis, Artificial Neural Network (ANN) technique is used to model and simulate the Turning Process. Significant machining parameters (i.e. spindle speed, feed rate, and, depths of cut) and process parameters (surface roughness and cutting forces) are considered. It is shown that Multi-Layer Back Propagation Neural Network is capable to perform this particular task. Design of Experiments approach is used for efficient selection of values of parameters used during experiments to reduce cost and time for experiments. The Particle Swarm Optimization methodology is used for constrained optimization of machining parameters to minimize surface roughness as well as cutting forces. ANN and Particle Swarm Optimization, two computational intelligence techniques when combined together, provide efficient computational strategy for finding optimum solutions. The proposed method is capable of handling multiple parameter optimization problems for processes that have non-linear relationship between input and output parameters e.g. milling, drilling etc. In addition, this methodology provides reliable, fast and efficient tool that can provide suitable solution to many problems faced by manufacturing industry today.
142

Falconet: Force-feedback Approach For Learning From Coaching And Observation Using Natural And Experiential Training

Stein, Gary 01 January 2009 (has links)
Building an intelligent agent model from scratch is a difficult task. Thus, it would be preferable to have an automated process perform this task. There have been many manual and automatic techniques, however, each of these has various issues with obtaining, organizing, or making use of the data. Additionally, it can be difficult to get perfect data or, once the data is obtained, impractical to get a human subject to explain why some action was performed. Because of these problems, machine learning from observation emerged to produce agent models based on observational data. Learning from observation uses unobtrusive and purely observable information to construct an agent that behaves similarly to the observed human. Typically, an observational system builds an agent only based on prerecorded observations. This type of system works well with respect to agent creation, but lacks the ability to be trained and updated on-line. To overcome these deficiencies, the proposed system works by adding an augmented force-feedback system of training that senses the agents intentions haptically. Furthermore, because not all possible situations can be observed or directly trained, a third stage of learning from practice is added for the agent to gain additional knowledge for a particular mission. These stages of learning mimic the natural way a human might learn a task by first watching the task being performed, then being coached to improve, and finally practicing to self improve. The hypothesis is that a system that is initially trained using human recorded data (Observational), then tuned and adjusted using force-feedback (Instructional), and then allowed to perform the task in different situations (Experiential) will be better than any individual step or combination of steps.
143

Wind Turbine Airfoil Optimization by Particle Swarm Method

Endo, Makoto January 2011 (has links)
No description available.
144

Multiple Ligand Simultaneous Docking (MLSD) and Its Applications to Fragment Based Drug Design and Drug Repositioning

Li, Huameng 06 January 2012 (has links)
No description available.
145

Från gråbrungrönt till ökenfärgat Är svensk säkerhetspolitik realistisk? En teoriprövande fallstudie med svenskt fokus, om små och medelstora staters ökade tendens att använda sig av militära medel internationellt

Malmgren, Johan January 2006 (has links)
Denna teoriprövande fallstudie försöker svara på frågan om små staters ökande militära internationella ambitioner, och villighet att ta militära risker är ett förväntat beteende utifrån ett brett realistisk perspektiv. I centrum för undersökningen går den svenska säkerhets- och försvarspolitiska utveckling under luppen. Uppsatsen har en hög abstraktionsnivå och under undersökningens gång görs tre nedslag som alla försöker belysa realismen aktualitet. Inledningsvis undersöks dagens oklara hotbild, för att därefter ta en närmare titt på de motåtgärder som EU- länderna gemensamt har bestämt sig för, varvid begreppet Peace support operations belyses ur ett realistiskt perspektiv. Slutligen diskuteras hur realismen kan förklara små staters agerande varvid olika möjligheter diskuteras. Detta leder fram till en slutsats som konstaterar att små staters militära aktivitet mycket väl kan öka hotet mot den egna staten snarare än att eliminera det, vilket inte är ett förväntat realistiskt beteende av små stater. Dock finns indikationer på att små stater, möjligen använder sig av militära medel för att indirekt maximera sin makt i andra samanhang. ( 26818 ord) / In this case study the pattern of small states increasing willingness to use military force on the international arena, is being used in order to test the realist theory. Are the actions taken by small states expected behavior according to a broad understanding of the realist theory? To find out, the Swedish military development is put in the center of this study. The study proceeds in three steps; first out is a closer look at the new security threat, next the counter measures is examined, in particular the Peace Support Operations. Finally the realist theory tries to explain the behavior of small states. The conclusion of this study indicates that the increasing willingness to take military risk actually can increase the level of threat against the small state. This is not an expected behavior of a small state. Although the study also indicate that small states use its military operation, to indirectly gain power in other fields of interest. (26818 words)
146

Formação de grupos em MOOCs utilizando Particle Swarm Optimization / Forming of groups in MOOCs using Particle Swarm Optimization

Ullmann, Matheus Rudolfo Diedrich 26 February 2016 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-06-01T10:57:51Z No. of bitstreams: 2 Dissertação - Matheus Rudolfo Diedrich Ullmann - 2016.pdf: 1264745 bytes, checksum: 65f8378224bd7fd700216a920f2da7a0 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-06-01T11:00:53Z (GMT) No. of bitstreams: 2 Dissertação - Matheus Rudolfo Diedrich Ullmann - 2016.pdf: 1264745 bytes, checksum: 65f8378224bd7fd700216a920f2da7a0 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-06-01T11:00:53Z (GMT). No. of bitstreams: 2 Dissertação - Matheus Rudolfo Diedrich Ullmann - 2016.pdf: 1264745 bytes, checksum: 65f8378224bd7fd700216a920f2da7a0 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The MassiveOpenOnlineCourses(MOOCs)areonlinecourseswithopenenrollment that involvingahugeamountofstudentsfromdifferentlocations,withdifferentback- grounds andinterests.Thelargenumberofstudentsimpliesahugeandunmanageable number ofinteractions.Thisfact,alongwiththedifferentinterestsofstudents,resulting in low-qualityinteractions.Duetothelargenumberofstudents,alsobecomesunviable composition manuallylearninggroups.DuetothesecharacteristicspresentinMOOCs, a methodforforminggroupswasdevelopedinthiswork,asanattempttoattendthedi- chotomy existsbetweenthecollective,whichinvolvestheformationofanonlinelearning community onamassivescale,andindividual,withdifferentinterests,priorknowledge and expectationsanddifferentleadershipprofiles.Fortheformationofgroups,anadapta- tion ofParticleSwarmOptimizationalgorithmwasproposedbasedonthreecriteria,kno- wledge level,interestsandleadershipprofiles,formingthengroupswithdifferentlevels of knowledge,similarinterestsanddistributedleadership,providingbetterinteractionand knowledgeconstruction.Werecreatedtwovariationsoftheproblem,withfivestudents and theothersix.Basedoncomputationaltests,thealgorithmdemonstratedthatableto attend thegroupingcriteriainasatisfactorycomputingtimeandismoreefficientthanthe model randomgroupsformation.Thetestsalsodemonstratedthatthealgorithmisrobust taking intoaccountthevariousdatasetsanditerationsvariations.Toevaluatethequality of interactionsandknowledgebuildingingroupsformedbythemethod,Acasestudy wasconducted;andfortheanalysisofthecollecteddiscourses,itwastakenasthebasis twomodelsofdiscourseanalysisfoundintheliterature.Theresultsofthecasestudy demonstrated thatthegroupsformedbytheproposedmethodachievedthebestresultsin the interactionsandknowledgeconstruction,whencomparedwithgroupsthatdonotuse it. / Os Massive OpenOnlineCourses (MOOCs) sãocursos online com inscriçõesabertas que envolvemumaenormequantidadedeestudantesdediferenteslocalidades,comdife- rentes backgrounds e interesses.Ograndenúmerodealunosimplicaemumaenormee não gerenciávelquantidadedeinterações.Estefato,juntamentecomosinteressesdife- rentes dosalunos,resultaeminteraçõesdebaixaqualidade.Devidoàgrandequantidade de alunos,tambémtorna-seinviávelacomposiçãodegruposdeaprendizagemdeforma manual. DevidoàessascaracterísticaspresentesnosMOOCs,ummétodoparaformação de gruposfoidesenvolvidonestetrabalho,comoumatentativaparaatenderadicoto- mia queexisteentreocoletivo,queenvolveaformaçãodeumacomunidade online de aprendizagem emumaescalamaciça,eoindividual,comdiferentesinteresses,conhe- cimentos prévioseexpectativasecomdiferentesperfisdeliderança.Paraaformação dos grupos,umaadaptaçãodoalgoritmo ParticleSwarmOptimization foi propostacom base emtrêscritérios,níveldeconhecimento,interesseseperfisdeliderança,formando então gruposcomníveisdeconhecimentodiferentes,interessessemelhanteseliderança distribuída,proporcionandoumamelhorinteraçãoeconstruçãodeconhecimento.Foram criadas duasvariaçõesdoproblema,umacomcincoalunoseoutracomseis.Combase em testescomputacionais,oalgoritmodemonstrouqueconsegueatenderoscritériosde agrupamento emumtempodecomputaçãosatisfatórioeémaiseficientequeomodelode formação degruposaleatório.Ostestesdemonstraramtambémqueoalgoritmoérobusto levandoemcontaosvariadosconjuntosdedadosevariaçõesdeiterações.Paraavaliara qualidade dasinteraçõeseaconstruçãodeconhecimentonosgruposformadospelomé- todo, umestudodecasofoirealizado;eparaaanálisedosdiscursoscoletados,tomou-se como basedoismodelosdeanálisedediscursopresentesnaliteratura.Oresultadodo estudo decasodemonstrouqueosgruposformadospelométodopropostoobtiveramos melhores resultadosnasinteraçõeseconstruçãodoconhecimento,quandocomparados com osgruposquenãooutilizaram.
147

Transmission planétaire magnétique : étude, optimisation et réalisation / Magnetic planetary transmission : study, optimisation and realisation

Gouda, Eid Abdelbaki Ahmed 20 June 2011 (has links)
Le travail présenté dans ce mémoire porte sur l'étude, l'optimisation et la réalisation d'une transmission planétaire magnétique. Dans notre thèse nous essayons de répondre à quelques questions intéressantes sur la possibilité de remplacer un train planétaire mécanique par un train planétaire magnétique, est-ce que la formule de Willis reste valable pour le train planétaire magnétique et est-ce que les trains magnétiques ont des performances similaires à celles des trains mécaniques ? Donc nous étudions, le remplacement du train mécanique par une transmission magnétique. Nous montrons que le train magnétique a un volume moindre, des pertes inférieures et plusieurs autres avantages. Notre but dans cette thèse est d'obtenir un "design" optimal d'un train magnétique. Nous utilisons un logiciel de calcul par éléments finis pour l'étude électromagnétique et nous cherchons également à optimiser les dimensions de ce train. Pour cela nous utilisons la méthode d'optimisation par essaim de particules (OEP). Un prototype a été réalisé ce qui permet de confronter les résultats de simulation et expérimentaux. / The work presented in this thesis deals with the study, the optimisation and the realisation of a magnetic planetary transmission. We try to answer some questions about the possibility of replacing the mechanical planetary gear used in industrial machines by a magnetic planetary gear; is the formula of Willis still valid for the magnetic planetary gear and are the magnetic planetary gear performances at least similar to ones of the mechanical gears? We study the replacement of the mechanical planetary gear by a magnetic one. We show that the magnetic one has a smaller volume, lower losses and many other benefits. The objective of this work is to obtain an optimum design of a magnetic planetary gear. We use a finite element software to study the magnetic behaviour of the device and we also perform the optimization of the dimensions of the magnetic planetary gear. The particle swarm optimization method (PSO) has been used. A prototype has been built so the computation results has been compared to the experimental ones.
148

Applications of Artificial Intelligence in Power Systems

Rastgoufard, Samin 18 May 2018 (has links)
Artificial intelligence tools, which are fast, robust and adaptive can overcome the drawbacks of traditional solutions for several power systems problems. In this work, applications of AI techniques have been studied for solving two important problems in power systems. The first problem is static security evaluation (SSE). The objective of SSE is to identify the contingencies in planning and operations of power systems. Numerical conventional solutions are time-consuming, computationally expensive, and are not suitable for online applications. SSE may be considered as a binary-classification, multi-classification or regression problem. In this work, multi-support vector machine is combined with several evolutionary computation algorithms, including particle swarm optimization (PSO), differential evolution, Ant colony optimization for the continuous domain, and harmony search techniques to solve the SSE. Moreover, support vector regression is combined with modified PSO with a proposed modification on the inertia weight in order to solve the SSE. Also, the correct accuracy of classification, the speed of training, and the final cost of using power equipment heavily depend on the selected input features. In this dissertation, multi-object PSO has been used to solve this problem. Furthermore, a multi-classifier voting scheme is proposed to get the final test output. The classifiers participating in the voting scheme include multi-SVM with different types of kernels and random forests with an adaptive number of trees. In short, the development and performance of different machine learning tools combined with evolutionary computation techniques have been studied to solve the online SSE. The performance of the proposed techniques is tested on several benchmark systems, namely the IEEE 9-bus, 14-bus, 39-bus, 57-bus, 118-bus, and 300-bus power systems. The second problem is the non-convex, nonlinear, and non-differentiable economic dispatch (ED) problem. The purpose of solving the ED is to improve the cost-effectiveness of power generation. To solve ED with multi-fuel options, prohibited operating zones, valve point effect, and transmission line losses, genetic algorithm (GA) variant-based methods, such as breeder GA, fast navigating GA, twin removal GA, kite GA, and United GA are used. The IEEE systems with 6-units, 10-units, and 15-units are used to study the efficiency of the algorithms.
149

粒子群最佳化演算法於估測基礎矩陣之應用 / Particle swarm optimization algorithms for fundamental matrix estimation

劉恭良, Liu, Kung Liang Unknown Date (has links)
基礎矩陣在影像處理是非常重要的參數,舉凡不同影像間對應點之計算、座標系統轉換、乃至重建物體三維模型等問題,都有賴於基礎矩陣之精確與否。本論文中,我們提出一個機制,透過粒子群最佳化的觀念來求取基礎矩陣,我們的方法不但能提高基礎矩陣的精確度,同時能降低計算成本。 我們從多視角影像出發,以SIFT取得大量對應點資料後,從中選取8點進行粒子群最佳化。取樣時,我們透過分群與隨機挑選以避免選取共平面之點。然後利用最小平方中值表來估算初始評估值,並遵循粒子群最佳化演算法,以最小疊代次數為收斂準則,計算出最佳之基礎矩陣。 實作中我們以不同的物體模型為標的,以粒子群最佳化與最小平方中值法兩者結果比較。實驗結果顯示,疊代次數相同的實驗,粒子群最佳化演算法估測基礎矩陣所需的時間,約為最小平方中值法來估測所需時間的八分之一,同時粒子群最佳化演算法估測出來的基礎矩陣之平均誤差值也優於最小平方中值法所估測出來的結果。 / Fundamental matrix is a very important parameter in image processing. In corresponding point determination, coordinate system conversion, as well as three-dimensional model reconstruction, etc., fundamental matrix always plays an important role. Hence, obtaining an accurate fundamental matrix becomes one of the most important issues in image processing. In this paper, we present a mechanism that uses the concept of Particle Swarm Optimization (PSO) to find fundamental matrix. Our approach not only can improve the accuracy of the fundamental matrix but also can reduce computation costs. After using Scale-Invariant Feature Transform (SIFT) to get a large number of corresponding points from the multi-view images, we choose a set of eight corresponding points, based on the image resolutions, grouping principles, together with random sampling, as our initial starting points for PSO. Least Median of Squares (LMedS) is used in estimating the initial fitness value as well as the minimal number of iterations in PSO. The fundamental matrix can then be computed using the PSO algorithm. We use different objects to illustrate our mechanism and compare the results obtained by using PSO and using LMedS. The experimental results show that, if we use the same number of iterations in the experiments, the fundamental matrix computed by the PSO method have better estimated average error than that computed by the LMedS method. Also, the PSO method takes about one-eighth of the time required for the LMedS method in these computations.
150

Maximiza??o da penetra??o da gera??o distribu?da atrav?s do algoritmo de otimiza??o nuvem de part?culas

Pires, Bezaliel Albuquerque da Silva 03 August 2011 (has links)
Made available in DSpace on 2014-12-17T14:55:52Z (GMT). No. of bitstreams: 1 BezalielASP_DISSERT.pdf: 2307069 bytes, checksum: aa5ddc5e2ae2722d27d66e85a1e511f1 (MD5) Previous issue date: 2011-08-03 / This work develops a methodology for defining the maximum active power being injected into predefined nodes in the studied distribution networks, considering the possibility of multiple accesses of generating units. The definition of these maximum values is obtained from an optimization study, in which further losses should not exceed those of the base case, i.e., without the presence of distributed generation. The restrictions on the loading of the branches and voltages of the system are respected. To face the problem it is proposed an algorithm, which is based on the numerical method called particle swarm optimization, applied to the study of AC conventional load flow and optimal load flow for maximizing the penetration of distributed generation. Alternatively, the Newton-Raphson method was incorporated to resolution of the load flow. The computer program is performed with the SCILAB software. The proposed algorithm is tested with the data from the IEEE network with 14 nodes and from another network, this one from the Rio Grande do Norte State, at a high voltage (69 kV), with 25 nodes. The algorithm defines allowed values of nominal active power of distributed generation, in percentage terms relative to the demand of the network, from reference values / Neste trabalho, prop?e-se uma metodologia para defini??o dos valores m?ximos de pot?ncia ativa a serem injetados em barras pr?-definidas das redes de distribui??o estudadas, considerando a possibilidade de m?ltiplos acessos de unidades geradoras. A defini??o desses valores m?ximos se obt?m a partir de um estudo de otimiza??o, no qual as novas perdas n?o superam as do caso base, ou seja, sem a presen?a da gera??o distribu?da. No estudo atendem-se as restri??es de carregamentos nos ramos e tens?es do sistema. Para tratar o problema, prop?e-se um algoritmo baseado no m?todo num?rico de otimiza??o nuvem de part?culas, ou particle swarm optimization PSO, aplicado ao estudo de fluxo de carga convencional CA e ao fluxo de carga ?timo para maximiza??o da penetra??o da gera??o distribu?da. Tamb?m se incorporou o m?todo de Newton-Raphson, como alternativa, para a resolu??o do fluxo de carga. Realiza-se a programa??o computacional no software SCILAB. Testa-se o algoritmo proposto com os dados da rede IEEE-14 barras e de uma rede de distribui??o em alta tens?o (69 kV) do Estado do Rio Grande do Norte, com 25 barras. O algoritmo determina valores permitidos de pot?ncia ativa nominal de gera??o distribu?da, em termos percentuais relativos ? demanda da rede, a partir de valores de refer?ncia

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