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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.
41

Measuring Group Separability in Geometrical Space for Evaluation of Pattern Recognition and Dimension Reduction Algorithms

Acevedo, Aldo, Duran, Claudio, Kuo, Ming-Ju, Ciucci, Sara, Schroeder, Michael, Cannistraci, Carlo Vittorio 22 January 2024 (has links)
Evaluating group separability is fundamental to pattern recognition. A plethora of dimension reduction (DR) algorithms has been developed to reveal the emergence of geometrical patterns in a lowdimensional space, where high-dimensional sample similarities are approximated by geometrical distances. However, statistical measures to evaluate the group separability attained by DR representations are missing. Traditional cluster validity indices (CVIs) might be applied in this context, but they present multiple limitations because they are not specifically tailored for DR. Here, we introduce a new rationale called projection separability (PS), which provides a methodology expressly designed to assess the group separability of data samples in a DR geometrical space. Using this rationale, we implemented a new class of indices named projection separability indices (PSIs) based on four statistical measures: Mann-Whitney U-test p-value, Area Under the ROC-Curve, Area Under the Precision-Recall Curve, and Matthews Correlation Coeffcient. The PSIs were compared to six representative cluster validity indices and one geometrical separability index using seven nonlinear datasets and six different DR algorithms. The results provide evidence that the implemented statistical-based measures designed on the basis of the PS rationale are more accurate than the other indices and can be adopted not only for evaluating and comparing group separability of DR results but also for fine-tuning DR algorithms' hyperparameters. Finally, we introduce a second methodological innovation termed trustworthiness, a statistical evaluation that accounts for separability uncertainty and associates to the measure of each index a p-value that expresses the significance level in comparison to a null model.
42

Essays on House Prices and Consumption

Song, In Ho 27 July 2011 (has links)
No description available.
43

The doctrine of separability in respect of the arbitration clause of a contract :|ba comparative study of English law and South African law / Anthony Lehlohonolo Ditedu

Ditedu, Anthony Lehlohonolo January 2014 (has links)
Most jurisdictions have over the past two decades experienced reforms with regard to arbitration law. These include England, America, France, Germany and the Netherlands. These reforms were necessary as the trend in the modern era shows that businessmen situated in different countries usually prefer to have their disputes resolved by arbitration as opposed to court litigation. To have disputes resolved effectively, it is surely a desirable thing to have laws that would promote the use of arbitration as an alternative dispute resolution. This would also ensure progressive international trade which is an important aspect of development in the South African constitutional state. One aspect of the law that would ensure a speedy and effective resolution of dispute by means of arbitration is the incorporation of the doctrine of separability in a country's law. The doctrine of separability provides that an arbitration agreement is a separate and independent contract from the main contract in which it is incorporated. In light of the above, the primary purpose of this study is to compare and analyse the English legal system with that of South Africa with specific focus on the doctrine of separability. / LLM (Import and Export Law), North-West University, Potchefstroom Campus, 2014
44

The doctrine of separability in respect of the arbitration clause of a contract :|ba comparative study of English law and South African law / Anthony Lehlohonolo Ditedu

Ditedu, Anthony Lehlohonolo January 2014 (has links)
Most jurisdictions have over the past two decades experienced reforms with regard to arbitration law. These include England, America, France, Germany and the Netherlands. These reforms were necessary as the trend in the modern era shows that businessmen situated in different countries usually prefer to have their disputes resolved by arbitration as opposed to court litigation. To have disputes resolved effectively, it is surely a desirable thing to have laws that would promote the use of arbitration as an alternative dispute resolution. This would also ensure progressive international trade which is an important aspect of development in the South African constitutional state. One aspect of the law that would ensure a speedy and effective resolution of dispute by means of arbitration is the incorporation of the doctrine of separability in a country's law. The doctrine of separability provides that an arbitration agreement is a separate and independent contract from the main contract in which it is incorporated. In light of the above, the primary purpose of this study is to compare and analyse the English legal system with that of South Africa with specific focus on the doctrine of separability. / LLM (Import and Export Law), North-West University, Potchefstroom Campus, 2014
45

Bodové procesy v čase a prostoru / Bodové procesy v čase a prostoru

Koubek, Antonín January 2013 (has links)
In this work we present an introduction to the theory of point processes in space and time with focus on space--time shot--noise Cox process. Further from theoretical point of view we study its simulation, space--time separability, kernel estimate of intensity function and non--parametric estimation of some summary statistics using edge corrections. For two ambit models and one space--time separable model we do numerical calculations using the presented theory and software Wolfram Mathematica 9.0. For these three models we do simulations, we select the best bandwidth for kernel estimate of the intensity function and we also calculate some theoretical summary statistics including the pair correlation function. Powered by TCPDF (www.tcpdf.org)
46

Filosofia da linguagem do século XX no conceito de direito de Herbert Hart

Campos, Fernando Rosa January 2018 (has links)
A presente dissertação de mestrado tenta estabelecer como e em qual medida o Conceito de Direito de Herbert Hart é influenciado por teorias da linguagem do século XX. Com este objetivo, são primeiro analisadas as passagens do livro e as considerações do autor que indicam uma influência de teses próprias da filosofia da linguagem em sua obra. Após, são expostas algumas intepretações do tema, tanto no sentido de concordar que existe esta relação entre as teses de Hart e a filosofia da linguagem do século 20, quanto no sentido de negar este vínculo. Especial atenção é atribuída a interpretação de Ronald Dworkin do tema, tendo em vista a sua relevância histórica e o fato do autor reconhecer a vinculação referida e a utilizá-la como base para críticas das teses do Conceito de direito. Estabelecidas estas interpretações divergentes, são então expostas as principais ideias e propostas dos filósofos da linguagem do ambiente acadêmico de Oxford, tendo em vista a relação e proximidade de Hart a estes autores. Expostas estas teses, diferentes pontos da carreira bibliográfica de Hart são analisados, com o objetivo de traçar a relação dos escritos do autor com as teorias recém vistas e de tentar estabelecer a evolução da linha argumentativa que culminou no Conceito de Direito. Uma vez que os argumentos dessa obra forem analisados e um entendimento específico dessas teses for defendido, as críticas de Dworkin e de outros autores são revistas. Este exercício, por fim, mostra como o entendimento defendido neste trabalho serve também como defesa contra algumas caracterizações da obra de Hart que considero equivocadas. / The main goal of this paper is to establish to what extent the work “The Concept of Law” was influenced by philosophical theories of language from the 20th century. First are considered some passages of this work, together with some pronouncements of its author Herbert Hart that appear to confirm that his theses were so influenced. Then are shown some interpretations that recognize the influence between the author and theses from the philosophy of language, together with other interpretations that deny this relationship. Special attention is given to the perception of Ronald Dworkin of the subject given its historical relevance and the fact that it recognize a relationship between these theses and uses it as basis for criticism of the arguments expressed in The Concept of Law. Once these distinctive interpretations are stablished, the main ideas and goals of the Oxford language philosophers, given their relationship and proximity to Hart, are exposed. Once these theses are dealt with, varied moments of the bibliography of Herbert Hart are considered in order to show the connection between his works and the language theses here exposed. After these point are considered and a distinct understanding of the subject is developed the criticism of Dworkin and other authors are retaken. This last point aims to show how the understanding developed in this paper also develops a defense of Hart’s theory from some mischaracterizations of his work.
47

Aprendizado de máquina baseado em separabilidade linear em sistema de classificação híbrido-nebuloso aplicado a problemas multiclasse

Tuma, Carlos Cesar Mansur 29 June 2009 (has links)
Made available in DSpace on 2016-06-02T19:05:36Z (GMT). No. of bitstreams: 1 2598.pdf: 3349204 bytes, checksum: 01649491fd1f03aa5a11b9191727f88b (MD5) Previous issue date: 2009-06-29 / Financiadora de Estudos e Projetos / This master thesis describes an intelligent classifier system applied to multiclass non-linearly separable problems called Slicer. The system adopts a low computacional cost supervised learning strategy (evaluated as ) based on linear separability. During the learning period the system determines a set of hyperplanes associated to oneclass regions (sub-spaces). In classification tasks the classifier system uses the hyperplanes as a set of if-then-else rules to infer the class of the input attribute vector (non classified object). Among other characteristics, the intelligent classifier system is able to: deal with missing attribute values examples; reject noise examples during learning; adjust hyperplane parameters to improve the definition of the one-class regions; and eliminate redundant rules. The fuzzy theory is considered to design a hybrid version with features such as approximate reasoning and parallel inference computation. Different classification methods and benchmarks are considered for evaluation. The classifier system Slicer reaches acceptable results in terms of accuracy, justifying future investigation effort. / Este trabalho de mestrado descreve um sistema classificador inteligente aplicado a problemas multiclasse não-linearmente separáveis chamado Slicer. O sistema adota uma estratégia de aprendizado supervisionado de baixo custo computacional (avaliado em ) baseado em separabilidade linear. Durante o período de aprendizagem o sistema determina um conjunto de hiperplanos associados a regiões de classe única (subespaços). Nas tarefas de classificação o sistema classificador usa os hiperplanos como um conjunto de regras se-entao-senao para inferir a classe do vetor de atributos dado como entrada (objeto a ser classificado). Entre outras caracteristicas, o sistema classificador é capaz de: tratar atributos faltantes; eliminar ruídos durante o aprendizado; ajustar os parâmetros dos hiperplanos para obter melhores regiões de classe única; e eliminar regras redundantes. A teoria nebulosa é considerada para desenvolver uma versão híbrida com características como raciocínio aproximado e simultaneidade no mecanismo de inferência. Diferentes métodos de classificação e domínios são considerados para avaliação. O sistema classificador Slicer alcança resultados aceitáveis em termos de acurácia, justificando investir em futuras investigações.
48

Contribution à la modélisation du comportement dynamique d'un dispositif élastomérique / Contribution to modeling the dynamic behavior of an elastomeric device

Jridi, Nidhal 20 September 2017 (has links)
Ce travail s’inscrit dans le cadre d’un partenariat international Airbus Safran Launchers ", " Ecole Centrale de Lyon " et " Ecole Nationale d’Ingénieurs de Tunis ". Les composés élastomériques sont largement utilisés dans l’industrie pour leurs déformabilité et leurs capacités d’amortissement. Soumis aux combinaisons complexes de fabrication et de charges de service, les élastomères montrent la capacité de subir des conditions de chargement sévères et le cas de pré-déformation statique superposée par une excitation dynamique de petite amplitude est couramment utilisé pour des applications industrielles, par exemple des pneus, des amortisseurs, applications aérospatiales ... Pour concevoir efficacement ces composés industriels, il est primordial de prédire la réponse des produits à travers des processus de modélisation simples qui ont multiplié les méthodes d’analyse: expérimentale, théorique et numérique. Dans ce contexte, le présent travail se concentre sur la conception et l’analyse des propriétés dynamiques d’un dispositif élastomère autour d’une configuration préformée. À cette fin, trois mélanges de caoutchouc ont été expérimentés: Caoutchouc naturel (NR), Bromobutyl (BIIR) et un mélange des deux (NR / BIIR). Une discussion est faite avec préoccupation pour la mise en place expérimentale ainsi que les procédures utilisées pour des essais expérimentaux efficaces. Avec ces conclusions, nous avons fait un jugement sur les capacités de prévision, dans les domaines temporels et fréquentiels, de certains modèles hyper-visco-élastique à base d’intégrale unique sous l’hypothèse de séparabilité des effets temps-déformation. Les modèles considérés sont largement utilisés pour les applications d’ingénierie. Ce travail est suivi d’une application sur un composant industriel. Dans le cadre de cette thèse, le code de calcul d’éléments finis ABAQUS 6.14 a été utilisé pour étudier les propriétés dynamiques de cette structure. Une méthodologie d’analyse a été présentée pour identifier soigneusement l’ensemble des paramètres dans le but de satisfaire certaines exigences industrielles, principalement des capacités de masse, de rigidité et d’amortissement. / This work is conducted as international collaboration with " Airbus Safran Launchers ", " Ecole Centrale de Lyon " and " National Engineering School of Tunis ". Elastomeric compounds are widely used in industry for their high deformability and damping capabilities. Subjected to complex combinations of manufacturing and service loadings, elastomers show the fact to undergo severe loading conditions and the load case of large static predeformation superimposed by small amplitude dynamic excitation is commonly encountred for industrial applications e.g tires, shock-absorbing bushes, construction industry, aerospace applications... To design such industrial compounds efficiently, it is of major importance to predict the response of the products through simple modeling processes which have multiplied analysis methods: experimental, theoretical and numerical. Within this context, the present work focuses on design and analysis of dynamic properties of an elastomeric device at a predeformed configuration. To this end, three rubber mixtures have been experimentally investigated: Natural Rubber (NR), Bromobutyl (BIIR) and a mixture of both (NR/BIIR). A discussion is made with concern to experimental set-up as well as the used procedures for an efficient specimens testings. Within these findings, we made judgement on the predictive capabilities, in time and frequency domains, of some single integral based hyper-visco-elastic models under time-strain seperability assumption. The considered models are widely used for engineering applications and focus have been made on the Simo model implemented in finite element commercial software Abaqus. This work is followed by an application on an industrial component. In the framework of this thesis, the finite element calculation code ABAQUS 6.14 was used to investigate the dynamic properties of such structure. An analysis methodology have been presented to carefully identify the set of parameters with the objective of satisfaction of some industrial requirements mainly mass, stiffness and damping capabilities.
49

Automorphisms of right-angled Artin groups / Automorphismes des groupes d'Artin à angles droits

Toinet, Emmanuel 11 May 2012 (has links)
Cette thèse a pour objet l’étude des automorphismes des groupes d’Artin à angles droits. Etant donné un graphe simple fini G, le groupe d’Artin à angles droits GG associé à G est le groupe défini par la présentation dont les générateurs sont les sommets de G, et dont les relateurs sont les commutateurs [v,w], où {v,w} est une paire de sommets adjacents. Le premier chapitre est conçu comme une introduction générale à la théorie des groupes d’Artin à angles droits et de leurs automorphismes. Dans un deuxième chapitre, on démontre que tout sous-groupe sous-normal d’indice une puissance de p d’un groupe d’Artin à angles droits est résiduellement p-séparable. Comme application de ce résultat, on montre que tout groupe d’Artin à angles droits est résiduellement séparable dans la classe des groupes nilpotents sans torsion. Une autre application de ce résultat est que le groupe des automorphismes extérieurs d’un groupe d’Artin à angles droits est virtuellement résiduellement p-fini. On montre également que le groupe de Torelli d’un groupe d’Artin à angles droits est résiduellement nilpotent sans torsion, et, par suite, résiduellement p-fini et bi-ordonnable. Dans un troisième chapitre, on établit une présentation du sous-groupe Conj(GG) deAut(GG) formé des automorphismes qui envoient chaque générateur sur un conjugué de lui-même / The purpose of this thesis is to study the automorphisms of right-angled Artin groups. Given a finite simplicial graph G, the right-angled Artin group GG associated to G is the group defined by the presentation whose generators are the vertices of G, and whose relators are commuta-tors of pairs of adjacent vertices. The first chapter is intended as a general introduction to the theory of right-angled Artin groups and their automor-phisms. In a second chapter, we prove that every subnormal subgroup ofp-power index in a right-angled Artin group is conjugacy p-separable. As an application, we prove that every right-angled Artin group is conjugacy separable in the class of torsion-free nilpotent groups. As another applica-tion, we prove that the outer automorphism group of a right-angled Artin group is virtually residually p-finite. We also prove that the Torelli group ofa right-angled Artin group is residually torsion-free nilpotent, hence residu-ally p-finite and bi-orderable. In a third chapter, we give a presentation of the subgroup Conj(GG) of Aut(GG) consisting of the automorphisms thats end each generator to a conjugate of itself
50

Three-dimensional hydrodynamic models coupled with GIS-based neuro-fuzzy classification for assessing environmental vulnerability of marine cage aquaculture

Navas, Juan Moreno January 2010 (has links)
There is considerable opportunity to develop new modelling techniques within a Geographic Information Systems (GIS) framework for the development of sustainable marine cage culture. However, the spatial data sets are often uncertain and incomplete, therefore new spatial models employing “soft computing” methods such as fuzzy logic may be more suitable. The aim of this study is to develop a model using Neuro-fuzzy techniques in a 3D GIS (Arc View 3.2) to predict coastal environmental vulnerability for Atlantic salmon cage aquaculture. A 3D hydrodynamic model (3DMOHID) coupled to a particle-tracking model is applied to study the circulation patterns, dispersion processes and residence time in Mulroy Bay, Co. Donegal Ireland, an Irish fjard (shallow fjordic system), an area of restricted exchange, geometrically complicated with important aquaculture activities. The hydrodynamic model was calibrated and validated by comparison with sea surface and water flow measurements. The model provided spatial and temporal information on circulation, renewal time, helping to determine the influence of winds on circulation patterns and in particular the assessment of the hydrographic conditions with a strong influence on the management of fish cage culture. The particle-tracking model was used to study the transport and flushing processes. Instantaneous massive releases of particles from key boxes are modelled to analyse the ocean-fjord exchange characteristics and, by emulating discharge from finfish cages, to show the behaviour of waste in terms of water circulation and water exchange. In this study the results from the hydrodynamic model have been incorporated into GIS to provide an easy-to-use graphical user interface for 2D (maps), 3D and temporal visualization (animations), for interrogation of results. v Data on the physical environment and aquaculture suitability were derived from a 3- dimensional hydrodynamic model and GIS for incorporation into the final model framework and included mean and maximum current velocities, current flow quiescence time, water column stratification, sediment granulometry, particulate waste dispersion distance, oxygen depletion, water depth, coastal protection zones, and slope. The Neuro-fuzzy classification model NEFCLASS–J, was used to develop learning algorithms to create the structure (rule base) and the parameters (fuzzy sets) of a fuzzy classifier from a set of classified training data. A total of 42 training sites were sampled using stratified random sampling from the GIS raster data layers, and the vulnerability categories for each were manually classified into four categories based on the opinions of experts with field experience and specific knowledge of the environmental problems investigated. The final products, GIS/based Neuro Fuzzy maps were achieved by combining modeled and real environmental parameters relevant to marine fin fish Aquaculture. Environmental vulnerability models, based on Neuro-fuzzy techniques, showed sensitivity to the membership shapes of the fuzzy sets, the nature of the weightings applied to the model rules, and validation techniques used during the learning and validation process. The accuracy of the final classifier selected was R=85.71%, (estimated error value of ±16.5% from Cross Validation, N=10) with a Kappa coefficient of agreement of 81%. Unclassified cells in the whole spatial domain (of 1623 GIS cells) ranged from 0% to 24.18 %. A statistical comparison between vulnerability scores and a significant product of aquaculture waste (nitrogen concentrations in sediment under the salmon cages) showed that the final model gave a good correlation between predicted environmental vi vulnerability and sediment nitrogen levels, highlighting a number of areas with variable sensitivity to aquaculture. Further evaluation and analysis of the quality of the classification was achieved and the applicability of separability indexes was also studied. The inter-class separability estimations were performed on two different training data sets to assess the difficulty of the class separation problem under investigation. The Neuro-fuzzy classifier for a supervised and hard classification of coastal environmental vulnerability has demonstrated an ability to derive an accurate and reliable classification into areas of different levels of environmental vulnerability using a minimal number of training sets. The output will be an environmental spatial model for application in coastal areas intended to facilitate policy decision and to allow input into wider ranging spatial modelling projects, such as coastal zone management systems and effective environmental management of fish cage aquaculture.

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