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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.
21

Visualization for frequent pattern mining

Carmichael, Christopher Lee 03 April 2013 (has links)
Data mining algorithms analyze and mine databases for discovering implicit, previously unknown and potentially useful knowledge. Frequent pattern mining algorithms discover sets of database items that often occur together. Many of the frequent pattern mining algorithms represent the discovered knowledge in the form of a long textual list containing these sets of frequently co-occurring database items. As the amount of discovered knowledge can be large, it may not be easy for most users to examine and understand such a long textual list of knowledge. In my M.Sc. thesis, I represent both the original database and the discovered knowledge in pictorial form. Specifically, I design a new interactive visualization system for viewing the original transaction data (which are then fed into the frequent pattern mining engine) and for revealing the interesting knowledge discovered from the transaction data in the form of mined patterns.
22

Exploring the lexical organization of English semantic fields and their collocational ranges

Kimmes, Anne January 2007 (has links)
Zugl.: Heidelberg, Univ., Diss., 2007 u.d.T.: Kimmes, Anne: Translation-based empirical analysis in semantic domains
23

[en] THEORETICAL-EXPERIMENTAL THERMAL STRESS ANALYSIS IN VISCOELASTIC CYLINDERS / [pt] ANÁLISE TEÓRICA-EXPERIMENTAL DE TENSÕES DE NATUREZA TÉRMICA EM UM CORPO CILÍNDRICO VISCOELÁSTICO

MARCELO FERREIRA PINTO URURAHY 03 April 2012 (has links)
[pt] Apresenta-se neste trabalho o desenvolvimento de um modelo teórico-numérico baseado na Teoria da Viscoelasticidade Linear capaz de prever as distribuições transientes e residuais das componentes de tensão e de deformação de um cilindro polimérico longo submetido a resfriamento brusco. Descrevem-se, ainda, os procedimentos experimentais adotados como intuito de se determinarem algumas propriedades térmicas e mecânicas do sistema epóxi DER331/XG0103/XB81215. Finalmente, comparam-se os resultados fornecidos pelo modelo teórico-numérico com resultados experimentais obtidos através da utilização de uma técnica extensométrica conhecida como Método de Sachs. / [en] This work presents the development of a theoretical and numerical model based on the Linear Viscoelastic Theory able to predict the transient and residual stress and deformation distributions in a long polymeric cylinder subject to a rapid cooling. The work describes the experimental procedures adopted aiming to determine some thermal and mechanical properties of the epoxy system DER331/XG0103/XB81215. Finally, the results from the theoretical numerical model are compared to the ones obtained experimentally by na extensometric technique known as Sachs’ Method.
24

Contribuição à formulação de um modelo de apuração de resultados da atividade de pesquisa e desenvolvimento de novos produtos na indústria têxtil: uma abordagem da gestão econômica / Contribution the formularization of a model of verification of results of the activity of research and development of new products in the textile industry: a boarding of the economic management.

Elias Dib Caddah Neto 18 December 2002 (has links)
É cada vez maior o número de empresas procurando diferenciais competitivos para atrair novos clientes. Um destes diferenciais é o desenvolvimento de novos produtos. As quantidades de recursos destinadas a esta atividade são, portanto, cada vez mais elevados. Diante disto, procurou-se discutir neste trabalho, o tratamento dado aos gastos com a pesquisa e desenvolvimento de novos produtos. Partindo-se de que, a forma dispensada a estes gastos pela contabilidade financeira não satisfaz as necessidades dos gestores, este estudo contribui para a formulação de um modelo de apuração de resultado para esta atividade, gerando informações que possam dar subsídios ao processo de gestão, fornecendo ao gestor uma mensuração mais adequada destes valores. O modelo apresentado, utilizando os conceitos da Gestão Econômica, evidencia a contribuição de cada área e atividade para o resultado global da empresa, atingindo assim o seu real valor econômico, destacando o processo de eficácia no desenvolvimento de produtos e estabelecendo requisitos para o modelo de apoio aos gestores na tomada de decisão. A aplicabilidade dos conceitos apresentados é demonstrada com o desenvolvimento de um exemplo hipotético, com a ocorrência de vários eventos relacionados à pesquisa e desenvolvimento de novos produtos. / The number of companies that are looking for competitione differential to attract new customers is increasing. One of these differentials is the development of new products. The amount of resources addressed to this activities are becoming higher and higher. So, this work tries to discuss the treatment given to the expenses with the research and development of new products. Since the way addressed to these expenses by the financial accounting doesn?t satisfy the necessities of the managers, this study contributes to the formulation of a cleasing model of results to this activity, producing information that can subsidize the process of management, giving to the manager a suitable mensuration of these values. The model presented, making use of the concepts of the Economic Management displays a contribution of each area and activity for the global result of the company, and thus, reaches its real economic value and outstands the process of efficacy in the development of the products and establishing condition for a prop model to the manager when they need to take a decision. The applicability of the concepts presented is demonstrate with the development of on hypothetical exemples with the happining of several events related with a research and development of new products.
25

[en] ON SPECTRAL RADIUS OF A CLASS OF OPERATORS TRANSFORMATIONS / [pt] SOBRE RAIOS ESPECTRAIS DE UMA CLASSE DE TRANSFORMAÇÕES DE OPERADORES

GISELLE MARTINS DOS SANTOS FERREIRA 26 June 2006 (has links)
[pt] As transformações F e F(diferente) surgiram associados ao problema de estabilidade em média-quadrática de sistemas bilineares discretos de dimensão infinita evoluindo em espaços de Hilbert separáveis, tendo sido originariamente definidas através de séries infinitas na álgebra de Banach dos operadores lineares e limitados no espaço de Hilbert em que o sistema evolui. O presente trabalho parte de uma condição suficiente para a estabilidade, condição esta anteriormente determinada, que se traduz imposições sobre os raios espectrais das transformações mencionadas ambos estritamente menores que um- e do fato já conhecido de que, a condição sendo parcialmente satisfeita, isto é, um dos raios espectrais menor que um, não implica que ela o seja por completo. Deste modo, coloca-se uma primeira questão: em que casos tal implicação existe? O estudo é então desenvolvido sobre a simplificação das condições que originaram: as transformações F e F (diferente) são tomadas simplificadamente como somas de apenas dois termos, e a questão inicial se converte na pesquisa de casos em que a igualdade entre raios espectrais de F e F(diferente) ocorre. Mais precisamente, os termos que compõem F e F(diferente) se constitui em produtos de operadores pertencentes à álgebra de Banach inicialmente referida, de modo que é feita uma análise do comportamento dos raios espectrais de F e F(diferente) situando-se esses operadores em classes específicas nessa álgebra. Sob estas condições são apresentados resultados relativos às classes dos operadores auto-adjuntos, unitários, normais, isometrias e subnormais, assim como um resultado referente aos shifts ponderados. Além disto, é apresentado um resultado geral para o caso de espaços de dimensão finita. / [en] The transformations f and F(different) appeared associated to the mean-square stability problem for infinite dimensional discrete bilinear systems evolving in a separable Hilbert space, being originally defined as infinite series in the Banach algebra of bounded linear operators on the Hilbert space where the system evolves. The present work starts with a previously defined sufficient stability condition, expressed by assumptions on the spectral radiuses of the mentioned transformations - both strictly less than one- and from the already known fact that the condition being partially fulfilled, that is, one of the spectral radiuses less than one, does not imply that it be so completely. Thus one poses a first question: in which cases does one have such an implication? The study is then developed on a simplification of the conditions from which it arose: both F and F(different) are taken as sums of only terms, and the initial question becomes the search for cases in which the equality betweem the spectral radiuses of F and F(different) occurs. More precisely, the terms that compose F and F(different) are products of operators in the above mentioned algebra, so that the behaviour of the spectral radiuses of F and F (different) is analysed by placing those operators in specific classes in that algebra. Under these assumptions, results related to the classes of self-adjoint, unitary, normal, isometries and subnormal operators are presented, as well as result referring to weighted shifts. Besides, a general result related to finite-dimensional spaces is also presented.
26

Comparison of Schema Matching Evaluations

Do, Hong-Hai, Melnik, Sergey, Rahm, Erhard 12 December 2018 (has links)
Recently, schema matching has found considerable interest in both research and practice. Determining matching components of database or XML schemas is needed in many applications, e.g. for E-business and data integration. Various schema matching systems have been developed to solve the problem semi-automatically. While there have been some evaluations, the overall effectiveness of currently available automatic schema matching systems is largely unclear. This is because the evaluations were conducted in diverse ways making it difficult to assess the effectiveness of each single system, let alone to compare their effectiveness. In this paper we survey recently published schema matching evaluations. For this purpose, we introduce the major criteria that influence the effectiveness of a schema matching approach and use these criteria to compare the various systems. Based on our observations, we discuss the requirements for future match implementations and evaluations.
27

Federated search to merge the results of the extracted functional requirements

Li, Xiang 22 August 2022 (has links)
No description available.
28

An improved model based segmentation approach and its application to volumetric study of subcortical structures in MRI brain data

Liu, Yuan 05 August 2010 (has links)
No description available.
29

Consumer Preferences for the Reporting of Genetic Variants of Uncertain Significance

Smith, Nichole 24 September 2012 (has links)
No description available.
30

Improving Web Search Ranking Using the Internet Archive

Li, Liyan 02 June 2020 (has links)
Current web search engines retrieve relevant results only based on the latest content of web pages stored in their indices despite the fact that many web resources update frequently. We explore possible techniques and data sources for improving web search result ranking using web page historical content change. We compare web pages with previous versions and separately model texts and relevance signals in the newly added, retained, and removed parts. We particularly examine the Internet Archive, the largest web archiving service thus far, for its effectiveness in improving web search performance. We experiment with a few possible retrieval techniques, including language modeling approaches using refined document and query representations built based on comparing current web pages to previous versions and Learning-to-rank methods for combining relevance features in different versions of web pages. Experimental results on two large-scale retrieval datasets (ClueWeb09 and ClueWeb12) suggest it is promising to use web page content change history to improve web search performance. However, it is worth mentioning that the actual effectiveness at this moment is affected by the practical coverage of the Internet Archive and the amount of regularly-changing resources among the relevant information related to search queries. Our work is the first step towards a promising area combining web search and web archiving, and discloses new opportunities for commercial search engines and web archiving services. / Master of Science / Current web search engines show search documents only based on the most recent version of web pages stored in their database despite the fact that many web resources update frequently. We explore possible techniques and data sources for improving web search result ranking using web page historical content change. We compare web pages with previous versions and get the newly added, retained, and removed parts. We examine the Internet Archive in particular, the largest web archiving service now, for its effectiveness in improving web search performance. We experiment with a few possible retrieval techniques, including language modeling approaches using refined document and query representations built based on comparing current web pages to previous versions and Learning-to-rank methods for combining relevance features in different versions of web pages. Experimental results on two large-scale retrieval datasets (ClueWeb09 and ClueWeb12) suggest it is promising to use web page content change history to improve web search performance. However, it is worth mentioning that the actual effectiveness at this point is affected by the practical coverage of the Internet Archive and the amount of ever-changing resources among the relevant information related to search queries. Our work is the first step towards a promising area combining web search and web archiving, and discloses new opportunities for commercial search engines and web archiving services.

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