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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.
11

Zpracování asociačních pravidel metodou vícekriteriálního shlukování / Post-processing of association rules by multicriterial clustering method

Kejkula, Martin January 2002 (has links)
Association rules mining is one of several ways of knowledge discovery in databases. Paradoxically, data mining itself can produce such great amounts of association rules that there is a new knowledge management problem: there can easily be thousands or even more association rules holding in a data set. The goal of this work is to design a new method for association rules post-processing. The method should be software and domain independent. The output of the new method should be structured description of the whole set of discovered association rules. The output should help user to work with discovered rules. The path to reach the goal I used is: to split association rules into clusters. Each cluster should contain rules, which are more similar each other than to rules from another cluster. The output of the method is such cluster definition and description. The main contribution of this Ph.D. thesis is the described new Multicriterial clustering association rules method. Secondary contribution is the discussion of already published association rules post-processing methods. The output of the introduced new method are clusters of rules, which cannot be reached by any of former post-processing methods. According user expectations clusters are more relevant and more effective than any former association rules clustering results. The method is based on two orthogonal clustering of the same set of association rules. One clustering is based on interestingness measures (confidence, support, interest, etc.). Second clustering is inspired by document clustering in information retrieval. The representation of rules in vectors like documents is fontal in this thesis. The thesis is organized as follows. Chapter 2 identify the role of association rules in the KDD (knowledge discovery in databases) process, using KDD methodologies (CRISP-DM, SEMMA, GUHA, RAMSYS). Chapter 3 define association rule and introduce characteristics of association rules (including interestingness measuress). Chapter 4 introduce current association rules post-processing methods. Chapter 5 is the introduction to cluster analysis. Chapter 6 is the description of the new Multicriterial clustering association rules method. Chapter 7 consists of several experiments. Chapter 8 discuss possibilities of usage and development of the new method.
12

Co-evolution pattern mining in dynamic attributed graphs / Fouille de motifs de co-evolution dans des graphes dynamiques attribués

Desmier, Elise 15 July 2014 (has links)
Cette thèse s'est déroulée dans le cadre du projet ANR FOSTER, "FOuille de données Spatio-Temporelles : application à la compréhension et à la surveillance de l'ERosion" (ANR-2010-COSI-012-02, 2011-2014). Dans ce contexte, nous nous sommes intéressés à la modélisation de données spatio-temporelles dans des graphes enrichis de sorte que des calculs de motifs sur de telles données permettent de formuler des hypothèses intéressantes sur les phénomènes à comprendre. Plus précisément, nous travaillons sur la fouille de motifs dans des graphes relationnels (chaque noeud est identifié de fa\c con unique), attribués (chaque noeud du graphe est décrit par des attributs qui sont ici numériques), et dynamiques (les valeurs des attributs et les relations entre les noeuds peuvent évoluer dans le temps). Nous proposons un nouveau domaine de motifs nommé motifs de co-évolution. Ce sont des triplets d'ensembles de noeuds, d'ensembles de pas de temps et d'ensembles d'attributs signés, c'est à dire des attributs associés à une tendance (croissance,décroissance). L'intérêt de ces motifs est de décrire un sous-ensemble des données qui possède un comportement spécifique et a priori intéressant pour conduire des analyses non triviales. Dans ce but, nous définissons deux types de contraintes, une contrainte sur la structure du graphe et une contrainte sur la co-évolution de la valeur des attributs portés par les noeuds. Pour confirmer la spécificité du motif par rapport au reste des données, nous définissons trois mesures de densité qui tendent à répondre à trois questions. À quel point le comportement des noeuds en dehors du motif est similaire à celui des noeuds du motif ? Quel est le comportement du motif dans le temps, est-ce qu'il apparaît soudainement ? Est-ce que les noeuds du motif ont un comportement similaire seulement sur les attributs du motif ou aussi en dehors ? Nous proposons l'utilisation d'une hiérarchie sur les attributs comme connaissance à priori de l'utilisateur afin d'obtenir des motifs plus généraux et adaptons l'ensemble des contraintes à l'utilisation de cette hiérarchie. Finalement, pour simplifier l'utilisation de l'algorithme par l'utilisateur en réduisant le nombre de seuils à fixer et pour extraire uniquement l'ensemble des motifs les plus intéressants, nous utilisons le concept de ``skyline'' réintroduit récemment dans le domaine de la fouille de données. Nous proposons ainsi trois algorithmes MINTAG, H-MINTAG et Sky-H-MINTAG qui sont complets pour extraire l'ensemble de tous les motifs qui respectent les différentes contraintes. L'étude des propriétés des contraintes (anti-monotonie, monotonie/anti-monotonie par parties) nous permet de les pousser efficacement dans les algorithmes proposés et d'obtenir ainsi des extractions sur des données réelles dans des temps raisonnables. / This thesis was conducted within the project ANR FOSTER, ``Spatio-Temporal Data Mining: application to the understanding and monitoring of erosion'' (ANR-2010-COSI-012-02, 2011-2014). In this context, we are interested in the modeling of spatio- temporal data in enriched graphs so that computation of patterns on such data can be used to formulate interesting hypotheses about phenomena to understand. Specifically, we are working on pattern mining in relational graphs (each vertex is uniquely identified), attributed (each vertex of the graph is described by numerical attributes) and dynamic (attribute values and relations between vertices may change over time). We propose a new pattern domain that has been called co-evolution patterns. These are trisets of vertices, times and signed attributes, i.e., attributes associated with a trend (increasing or decreasing). The interest of these patterns is to describe a subset of the data that has a specific behaviour and a priori interesting to conduct non-trivial analysis. For this purpose, we define two types of constraints, a constraint on the structure of the graph and a constraint on the co-evolution of the value worn by vertices attributes. To confirm the specificity of the pattern with regard to the rest of the data, we define three measures of density that tend to answer to three questions. How similar is the behaviour of the vertices outside the co-evolution pattern to the ones inside it? What is the behaviour of the pattern over time, does it appear suddenly? Does the vertices of the pattern behave similarly only on the attributes of the pattern or even outside? We propose the use of a hierarchy of attributes as an a priori knowledge of the user to obtain more general patterns and we adapt the set of constraints to the use of this hierarchy. Finally, to simplify the use of the algorithm by the user by reducing the number of thresholds to be set and to extract only all the most interesting patterns, we use the concept of ``skyline'' reintroduced recently in the domain of data mining. We propose three constraint-based algorithms, called MINTAG, H-MINTAG and Sky-H-MINTAG, that are complete to extract the set of all patterns that meet the different constraints. These algorithms are based on constraints, i.e., they use the anti-monotonicity and piecewise monotonicity/anti-monotonicity properties to prune the search space and make the computation feasible in practical contexts. To validate our method, we experiment on several sets of data (graphs) created from real-world data.

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