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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

Data Visualization for the Benchmarking Engine

Joish, Sudha 16 May 2003 (has links)
In today's information age, data collection is not the ultimate goal; it is simply the first step in extracting knowledge-rich information to shape future decisions. In this thesis, we present ChartVisio - a simple web-based visual data-mining system that lets users quickly explore databases and transform raw data into processed visuals. It is highly interactive, easy to use and hides the underlying complexity of querying from its users. Data from tables is internally mapped into charts using aggregate functions across tables. The tool thus integrates querying and charting into a single general-purpose application. ChartVisio has been designed as a component of the Benchmark data engine, being developed at the Computer Science department, University of New Orleans. The data engine is an intelligent website generator and users who create websites using the Data Engine are the site owners. Using ChartVisio, owners may generate new charts and save them as XML templates for prospective website surfers. Everyday Internet users may view saved charts with the touch of a button and get real-time data, since charts are generated dynamically. Website surfers may also generate new charts, but may not save them as templates. As a result, even non-technical users can design and generate charts with minimal time and effort.
2

Visually Mining Interesting Patterns in Multivariate Datasets

Guo, Zhenyu 06 January 2013 (has links)
Data mining for patterns and knowledge discovery in multivariate datasets are very important processes and tasks to help analysts understand the dataset, describe the dataset, and predict unknown data values. However, conventional computer-supported data mining approaches often limit the user from getting involved in the mining process and performing interactions during the pattern discovery. Besides, without the visual representation of the extracted knowledge, the analysts can have difficulty explaining and understanding the patterns. Therefore, instead of directly applying automatic data mining techniques, it is necessary to develop appropriate techniques and visualization systems that allow users to interactively perform knowledge discovery, visually examine the patterns, adjust the parameters, and discover more interesting patterns based on their requirements. In the dissertation, I will discuss different proposed visualization systems to assist analysts in mining patterns and discovering knowledge in multivariate datasets, including the design, implementation, and the evaluation. Three types of different patterns are proposed and discussed, including trends, clusters of subgroups, and local patterns. For trend discovery, the parameter space is visualized to allow the user to visually examine the space and find where good linear patterns exist. For cluster discovery, the user is able to interactively set the query range on a target attribute, and retrieve all the sub-regions that satisfy the user's requirements. The sub-regions that satisfy the same query and are neareach other are grouped and aggregated to form clusters. For local pattern discovery, the patterns for the local sub-region with a focal point and its neighbors are computationally extracted and visually represented. To discover interesting local neighbors, the extracted local patterns are integrated and visually shown to the analysts. Evaluations of the three visualization systems using formal user studies are also performed and discussed.
3

Métodos de visualização de informações na descoberta de conhecimento em bases de dados

Maria Rocha de Holanda Vasconcelos, Denise January 2005 (has links)
Made available in DSpace on 2014-06-12T16:01:08Z (GMT). No. of bitstreams: 2 arquivo7170_1.pdf: 2203364 bytes, checksum: a4b1c6049227e992e107cabafa05f77c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / A descoberta de conhecimento em bases de dados (Knowledge Discovery in Databases KDD) visa a apoiar os processos de tomada de decisão através da extração automática de conhecimento oculto, útil e estratégico, em grandes bases de dados. Este conhecimento precisa ser analisado e facilmente entendido por usuários e gestores para que se torne realmente relevante nas operações cotidianas ou em planejamento de ações no contexto do problema analisado. O conhecimento descoberto pode ser apresentado de diversas formas. Entretanto, estas formas muitas vezes não são compreendidas pelo usuário ou não permitem análises detalhadas e validações de novas hipóteses. Para auxiliar a interpretação de resultados obtidos na mineração de dados, técnicas gráficas de Visualização de Informações têm contribuído significativamente para a representação inteligente de grandes volumes de dados, para a aplicação de técnicas estatísticas na análise de dados e para a manipulação visual dos dados. À aplicação dessas técnicas sobre o processo de KDD dá-se o nome de Visual Data Mining. Os principais objetivos deste trabalho são a investigação de técnicas de Visualização de Informações aplicadas no processo de KDD, o desenvolvimento de uma ferramenta de software que tenha foco principal em Visual Data Mining, com a proposição e implementação de técnicas e métodos que melhor se adaptem à interpretação de resultados minerados, e a realização de um estudo de caso com um problema em larga escala para validação da ferramenta desenvolvida. A ferramenta desenvolvida, denominada VisualDATAMINER , atua sobre a interpretação de regras de indução, permite a integração com ferramentas de mineração de dados, possibilita a visualização dos resultados de mineração de dados em diversas visões e a interação com estas visualizações através de métodos de interação. Desenvolvida na linguagem Java, a VisualDATAMINER apresenta todos os benefícios do paradigma de orientação a objetos como re-usabilidade, manutenibilidade e encapsulamento. A investigação experimental realizada usando uma base de dados com um grande volume de dados, no domínio de análise de crédito ao consumidor, mostrou o refinamento do conhecimento descoberto através da aplicação das técnicas de visualização de informações e dos métodos de interação propostos na ferramenta, atestando a eficácia e a eficiência da ferramenta desenvolvida
4

Integrando projeções multidimensionais à analise visual de redes sociais / Integrating multidimensional projections into visual analysis of social networks

Andery, Gabriel de Faria 13 September 2010 (has links)
Há várias décadas, pesquisadores em ciências sociais buscam formas gráficas para expressar as relações humanas na sociedade. O advento do computador e, mais recentemente, da internet, possibilitou o surgimento de um campo que tem despertado a atenção de estudiosos das áreas de visualização de informação e de ciências sociais, o da visualização de redes sociais. Esse campo tem o potencial de revelar e explorar padrões que podem beneficiar um número muito grande de aplicações e indivíduos em áreas tais como comércio, segurança em geral, redes de conhecimento e pesquisa de mercado. Grande parte dos algoritmos de visualização de redes sociais são baseados em grafos, destacando relacionamentos entre indivíduos e grupos de indivíduos, mas dando pouca atenção aos seus demais atributos. Assim, este trabalho apresenta um conjunto de soluções para representar e explorar visualmente redes sociais levando em consideração tais atributos. A primeira solução faz uso de redes heterogêneas, onde tanto indivíduos quanto comunidades são representados no grafo; a segunda solução utiliza técnicas de visualização baseadas em projeção multidimensional, que promovem o posicionamento dos dados no plano de acordo com algum critério de similaridade baseado em atributo; e a última solução coordena múltiplas visões para focar rapidamente em regiões de interesse. Os resultados indicam que as soluções proveem um poder de representação e identificação de conceitos não facilmente detectados por formas convencionais de visualização e exploração de grafos, com indícios fornecidos através dos estudos de caso e da realização de avaliações com usuários. Este trabalho fornece um estudo das áreas de visualização em grafos para a análise de redes sociais bem como uma implementação das soluções de integração da visualização em redes com as projeções multidimensionais / For decades, social sciences researchers have searched for graphical forms to express human social relationships. The development of computer science and more recently of the Internet has given rise to a new field of research for visualization and social sciences professionals, that of social network visualization. This field can potentially offer new opportunities in reveal new patterns that can benefit a large number of applications and individuals in fields such as commerce, security, knowledge networks and marketing. A large part of social network visualization algorithms and systems relies on graph representations, highlighting relationships amongst individuals and groups of individuals, but mostly neglecting the other available attributes of individuals. Thus, this work presents a set of tools to represent and explore social networks visually, taking into consideration the attributes of the nodes. The first technique employs heterogeneous networks, where both individuals and communities are represented in the graph; the second solution uses visualization techniques based on multidimensional projection, which promote the placement of data in the plane according to some similarity criterion based on attribute; still another proposed technique coordinates multiple views in order to speed up focus in regions of interest in the data sets. The results indicate that the solutions promote high degree of representation power and that concept identification not easily obtained via other methods is possible; the evidence comes from case studies as well as a user evaluation. This work includes a study in the area of graph visualization for social network analysis as well as a system implementing the proposed solutions, that integrate network visualization and multidimensional projections to extract patterns from social networks
5

Visual Data Mining : An Approach to Hybrid 3D Visualization

Zall, Davood January 2012 (has links)
By increasing the volume and complexity of datasets, Visual Data Mining (VDM), new visualization techniques evolved and new techniques released. However, some of these techniques performing well and cover all expectations; the others failed to save their positions. The main issue of such techniques is problem dependency.In this study, after a short description about necessity of Visual Data Mining techniques, I will provide a classified review of previous researches. This will result in a deep understanding as well as simple accessibility to previous researches, in a concise manner. This will facilitate the extraction of the specifications of 3D visualization technique and will provide a comprehensive knowledge of this technique in a classified manner. After that, all possible combination of 3D visualization technique will review.3D Visualization technique as a popular technique is a concrete foundation for visualization of multi-dimensional datasets, but it has some limitations. To overcome these limitations, previous studies in literature as well as the experiences of professionals will gather. The results will prove the theoretical findings as well as offering new hybrid techniques (combination with 3D visualization and other visual data mining techniques).The contribution of professionals will empower and complement the results of this study, as they can address solutions for the weaknesses of 3D Visualization technique in their business which is new combination of techniques. These combinations of techniques will create the basis for future researches in order to discover new limitations and provide solutions to overcome by use of hybrid techniques. / Program: Magisterutbildning i informatik
6

Super Spider: uma ferramenta versátil para exploração de dados multi-dimensionais representados por malhas de triângulos / Super Spider: a versatile tool for multi-dimensional data represented as triangle meshes

Watanabe, Lionis de Souza 11 April 2007 (has links)
Este trabalho apresenta o Super Spider: um sistema de exploração visual baseado no Spider Cursor, que abrange várias técnicas interativas da área de Visualização Computacional e conta com novos recursos de auxílio à investigação visual, além de ser uma ferramenta portável e flexível. / This work presents the Super Spider: a visual exploration system, based on Spider Cursor, that embraces many interactive techniques of Computer Visualization area and take into account innovative techniques to aid visual investigation, besides consisting of a portable and flexible tool.
7

Analytical tools and information-sharing methods supporting road safety organizations

Abugessaisa, Imad January 2008 (has links)
A prerequisite for improving road safety are reliable and consistent sources of information about traffic and accidents, which will help assess the prevailing situation and give a good indication of their severity. In many countries there is under-reporting of road accidents, deaths and injuries, no collection of data at all, or low quality of information. Potential knowledge is hidden, due to the large accumulation of traffic and accident data. This limits the investigative tasks of road safety experts and thus decreases the utilization of databases. All these factors can have serious effects on the analysis of the road safety situation, as well as on the results of the analyses. This dissertation presents a three-tiered conceptual model to support the sharing of road safety–related information and a set of applications and analysis tools. The overall aim of the research is to build and maintain an information-sharing platform, and to construct mechanisms that can support road safety professionals and researchers in their efforts to prevent road accidents. GLOBESAFE is a platform for information sharing among road safety organizations in different countries developed during this research. Several approaches were used, First, requirement elicitation methods were used to identify the exact requirements of the platform. This helped in developing a conceptual model, a common vocabulary, a set of applications, and various access modes to the system. The implementation of the requirements was based on iterative prototyping. Usability methods were introduced to evaluate the users’ interaction satisfaction with the system and the various tools. Second, a system-thinking approach and a technology acceptance model were used in the study of the Swedish traffic data acquisition system. Finally, visual data mining methods were introduced as a novel approach to discovering hidden knowledge and relationships in road traffic and accident databases. The results from these studies have been reported in several scientific articles.
8

A visualization framework for exploring correlations among atributes of a large dataset and its applications in data mining

Techaplahetvanich, Kesaraporn January 2007 (has links)
[Truncated abstract] Many databases in scientific and business applications have grown exponentially in size in recent years. Accessing and using databases is no longer a specialized activity as more and more ordinary users without any specialized knowledge are trying to gain information from databases. Both expert and ordinary users face significant challenges in understanding the information stored in databases. The databases are so large in most cases that it is impossible to gain useful information by inspecting data tables, which are the most common form of storing data in relational databases. Visualization has emerged as one of the most important techniques for exploring data stored in large databases. Appropriate visualization techniques can reveal trends, correlations and associations in data that are very difficult to understand from a textual representation of the data. This thesis presents several new frameworks for data visualization and visual data mining. The first technique, VisEx, is useful for visual exploration of large multi-attribute datasets and especially for exploring the correlations among the attributes in such datasets. Most previous visualization techniques can display correlations among two or three attributes at a time without excessive screen clutter. ... Although many algorithms for mining association rules have been researched extensively, they do not incorporate users in the process and most of them generate a large number of association rules. It is quite often difficult for the user to analyze a large number of rules to identify a small subset of rules that is of importance to the user. In this thesis I present a framework for the user to interactively mine association rules visually. Another challenging task in data mining is to understand the correlations among the mined association rules. It is often difficult to identify a relevant subset of association rules from a large number of mined rules. A further contribution of this thesis is a simple framework in the VisAR system that allows the user to explore a large number of association rules visually. A variety of businesses have adopted new technologies for storing large amounts of data. Analysis of historical data quite often offers new insights into business processes that may increase productivity and profit. On-line analytical processing (OLAP) has become a powerful tool for business analysts to explore historical data. Effective visualization techniques are very important for supporting OLAP technology. A new technique for the visual exploration of OLAP data cubes is also presented in this thesis.
9

Super Spider: uma ferramenta versátil para exploração de dados multi-dimensionais representados por malhas de triângulos / Super Spider: a versatile tool for multi-dimensional data represented as triangle meshes

Lionis de Souza Watanabe 11 April 2007 (has links)
Este trabalho apresenta o Super Spider: um sistema de exploração visual baseado no Spider Cursor, que abrange várias técnicas interativas da área de Visualização Computacional e conta com novos recursos de auxílio à investigação visual, além de ser uma ferramenta portável e flexível. / This work presents the Super Spider: a visual exploration system, based on Spider Cursor, that embraces many interactive techniques of Computer Visualization area and take into account innovative techniques to aid visual investigation, besides consisting of a portable and flexible tool.
10

Integrando projeções multidimensionais à analise visual de redes sociais / Integrating multidimensional projections into visual analysis of social networks

Gabriel de Faria Andery 13 September 2010 (has links)
Há várias décadas, pesquisadores em ciências sociais buscam formas gráficas para expressar as relações humanas na sociedade. O advento do computador e, mais recentemente, da internet, possibilitou o surgimento de um campo que tem despertado a atenção de estudiosos das áreas de visualização de informação e de ciências sociais, o da visualização de redes sociais. Esse campo tem o potencial de revelar e explorar padrões que podem beneficiar um número muito grande de aplicações e indivíduos em áreas tais como comércio, segurança em geral, redes de conhecimento e pesquisa de mercado. Grande parte dos algoritmos de visualização de redes sociais são baseados em grafos, destacando relacionamentos entre indivíduos e grupos de indivíduos, mas dando pouca atenção aos seus demais atributos. Assim, este trabalho apresenta um conjunto de soluções para representar e explorar visualmente redes sociais levando em consideração tais atributos. A primeira solução faz uso de redes heterogêneas, onde tanto indivíduos quanto comunidades são representados no grafo; a segunda solução utiliza técnicas de visualização baseadas em projeção multidimensional, que promovem o posicionamento dos dados no plano de acordo com algum critério de similaridade baseado em atributo; e a última solução coordena múltiplas visões para focar rapidamente em regiões de interesse. Os resultados indicam que as soluções proveem um poder de representação e identificação de conceitos não facilmente detectados por formas convencionais de visualização e exploração de grafos, com indícios fornecidos através dos estudos de caso e da realização de avaliações com usuários. Este trabalho fornece um estudo das áreas de visualização em grafos para a análise de redes sociais bem como uma implementação das soluções de integração da visualização em redes com as projeções multidimensionais / For decades, social sciences researchers have searched for graphical forms to express human social relationships. The development of computer science and more recently of the Internet has given rise to a new field of research for visualization and social sciences professionals, that of social network visualization. This field can potentially offer new opportunities in reveal new patterns that can benefit a large number of applications and individuals in fields such as commerce, security, knowledge networks and marketing. A large part of social network visualization algorithms and systems relies on graph representations, highlighting relationships amongst individuals and groups of individuals, but mostly neglecting the other available attributes of individuals. Thus, this work presents a set of tools to represent and explore social networks visually, taking into consideration the attributes of the nodes. The first technique employs heterogeneous networks, where both individuals and communities are represented in the graph; the second solution uses visualization techniques based on multidimensional projection, which promote the placement of data in the plane according to some similarity criterion based on attribute; still another proposed technique coordinates multiple views in order to speed up focus in regions of interest in the data sets. The results indicate that the solutions promote high degree of representation power and that concept identification not easily obtained via other methods is possible; the evidence comes from case studies as well as a user evaluation. This work includes a study in the area of graph visualization for social network analysis as well as a system implementing the proposed solutions, that integrate network visualization and multidimensional projections to extract patterns from social networks

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