• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 27
  • 9
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 46
  • 46
  • 16
  • 16
  • 13
  • 12
  • 10
  • 10
  • 10
  • 9
  • 9
  • 8
  • 8
  • 7
  • 6
  • 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.
31

Ontologias no processo de indexação automática de documentos textuais /

Pansani Junior, Eder Antonio. January 2016 (has links)
Orientador: Edberto Ferneda / Banca: Mariângela Spotti Lopes Fujita / Banca: Elvis Fusco / Resumo: Apesar dos avanços tecnológicos das últimas décadas, a busca por informações relevantes ainda é uma tarefa árdua. A recuperação de informação envolve, por um lado, um acervo documental que deve ser representado por expressões linguísticas que resumem seu conteúdo temático. Por outro lado, pessoas tentam descrever linguisticamente as suas necessidades de informação a fim de obterem documentos relevantes para satisfazer tais necessidades. Um sistema de recuperação de informação é, portanto, um elemento mediador entre um acervo documental e seus requisitantes. Um dos aspectos que interferem diretamente na sua eficiência é a forma como os documentos são representados. Sendo assim, pesquisas sobre indexação automática tomam importância, principalmente em ambiente de grande produção e disseminação de documentos, como é o caso da Web. A utilização de vocabulários controlados como elementos de normalização terminológica é um recurso utilizado para melhorar os resultados do processo de indexação. Este trabalho tem por objetivo propor, avaliar e desenvolver um método de utilização de ontologias no processo de indexação automática de documentos textuais, fazendo uso da estrutura lógica e conceitual das ontologias de domínio e implementado um método que permite aos sistemas de indexação automática a realização de inferências automáticas, favorecendo uma representação dos documentos mais semântica e abrangente. Conclui-se com o estudo que a utilização das ontologias como vocabulários cont... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Despite the technological advances of recent decades, the search for relevant information is still an arduous task. The information retrieval involves, on the one hand, a documentary collection that must be represented by linguistic expressions which summarize its thematic content. On the other hand, people try describing linguistically their information needs in order to obtain relevant documents to satisfy those needs. An information retrieval system is therefore a mediating element between a documentary collection and its requesters. One of the aspects that directly interferes in their efficiency is how documents are represented. Therefore, researches on automatic indexing take importance, particularly, in an environment of large production and dissemination of documents, as it's the case of the Web. The use of controlled vocabularies as terminology standardization elements is a feature used to improve the results of the indexing process. This study aims to propose, evaluate and develop a method for using ontologies in the automatic indexing process of textual documents, making use of logical and conceptual structure of domain ontologies and implementing a method that enables automatic indexing systems, an execution of automatic inferences, favoring a semantic and comprehensive documents representation. The study conclusion is that the use of ontologies as controlled vocabularies in automatic indexing systems can offer promising results, allowing the automatic discovery of... (Complete abstract click electronic access below) / Mestre
32

Detecção rápida de legendas em vídeos utilizando o ritmo visual / Fast video caption detection based on visual rhythm

Valio, Felipe Braunger, 1984- 19 August 2018 (has links)
Orientadores: Neucimar Jerônimo Leite, Hélio Pedrini / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-19T05:52:55Z (GMT). No. of bitstreams: 1 Valio_FelipeBraunger_M.pdf: 3505580 bytes, checksum: 3b20a046a5822011c617729904457d95 (MD5) Previous issue date: 2011 / Resumo: Detecção de textos em imagens é um problema que vem sendo estudado a várias décadas. Existem muitos trabalhos que estendem os métodos existentes para uso em análise de vídeos, entretanto, poucos deles criam ou adaptam abordagens que consideram características inerentes dos vídeos, como as informações temporais. Um problema particular dos vídeos, que será o foco deste trabalho, é o de detecção de legendas. Uma abordagem rápida para localizar quadros de vídeos que contenham legendas é proposta baseada em uma estrutura de dados especial denominada ritmo visual. O método é robusto à detecção de legendas com respeito ao alfabeto utilizado, ao estilo de fontes, à intensidade de cores e à orientação das legendas. Vários conjuntos de testes foram utilizados em nosso experimentos para demonstrar a efetividade do método / Abstract: Detection of text in images is a problem that has been studied for several decades. There are many works that extend the existing methods for use in video analysis, however, few of them create or adapt approaches that consider the inherent characteristics of video, such as temporal information. A particular problem of the videos, which will be the focus of this work, is the detection of subtitles. A fast method for locating video frames containing captions is proposed based on a special data structure called visual rhythm. The method is robust to the detection of legends with respect to the used alphabet, font style, color intensity and subtitle orientation. Several datasets were used in our experiments to demonstrate the effectiveness of the method / Mestrado / Ciência da Computação / Mestre em Ciência da Computação
33

Redundancy on content-based indexing.

January 1997 (has links)
by Cheung King Lum Kingly. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 108-110). / Abstract --- p.ii / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Problems in Content-Based Indexing --- p.2 / Chapter 1.3 --- Contributions --- p.3 / Chapter 1.4 --- Thesis Organization --- p.4 / Chapter 2 --- Content-Based Indexing Structures --- p.5 / Chapter 2.1 --- R-Tree --- p.6 / Chapter 2.2 --- R+-Tree --- p.8 / Chapter 2.3 --- R*-Tree --- p.11 / Chapter 3 --- Searching in Both R-Tree and R*-Tree --- p.15 / Chapter 3.1 --- Exact Search --- p.15 / Chapter 3.2 --- Nearest Neighbor Search --- p.19 / Chapter 3.2.1 --- Definition of Searching Metrics --- p.19 / Chapter 3.2.2 --- Pruning Heuristics --- p.21 / Chapter 3.2.3 --- Nearest Neighbor Search Algorithm --- p.24 / Chapter 3.2.4 --- Generalization to N-Nearest Neighbor Search --- p.25 / Chapter 4 --- An Improved Nearest Neighbor Search Algorithm for R-Tree --- p.29 / Chapter 4.1 --- Introduction --- p.29 / Chapter 4.2 --- New Pruning Heuristics --- p.31 / Chapter 4.3 --- An Improved Nearest Neighbor Search Algorithm --- p.34 / Chapter 4.4 --- Replacing Heuristics --- p.36 / Chapter 4.5 --- N-Nearest Neighbor Search --- p.41 / Chapter 4.6 --- Performance Evaluation --- p.45 / Chapter 5 --- Overlapping Nodes in R-Tree and R*-Tree --- p.53 / Chapter 5.1 --- Overlapping Nodes --- p.54 / Chapter 5.2 --- Problem Induced By Overlapping Nodes --- p.57 / Chapter 5.2.1 --- Backtracking --- p.57 / Chapter 5.2.2 --- Inefficient Exact Search --- p.57 / Chapter 5.2.3 --- Inefficient Nearest Neighbor Search --- p.60 / Chapter 6 --- Redundancy On R-Tree --- p.64 / Chapter 6.1 --- Motivation --- p.64 / Chapter 6.2 --- Adding Redundancy on Index Tree --- p.65 / Chapter 6.3 --- R-Tree with Redundancy --- p.66 / Chapter 6.3.1 --- Previous Models of R-Tree with Redundancy --- p.66 / Chapter 6.3.2 --- Redundant R-Tree --- p.70 / Chapter 6.3.3 --- Level List --- p.71 / Chapter 6.3.4 --- Inserting Redundancy to R-Tree --- p.72 / Chapter 6.3.5 --- Properties of Redundant R-Tree --- p.77 / Chapter 7 --- Searching in Redundant R-Tree --- p.82 / Chapter 7.1 --- Exact Search --- p.82 / Chapter 7.2 --- Nearest Neighbor Search --- p.86 / Chapter 7.3 --- Avoidance of Multiple Accesses --- p.89 / Chapter 8 --- Experiment --- p.90 / Chapter 8.1 --- Experimental Setup --- p.90 / Chapter 8.2 --- Exact Search --- p.91 / Chapter 8.2.1 --- Clustered Data --- p.91 / Chapter 8.2.2 --- Real Data --- p.93 / Chapter 8.3 --- Nearest Neighbor Search --- p.95 / Chapter 8.3.1 --- Clustered Data --- p.95 / Chapter 8.3.2 --- Uniform Data --- p.98 / Chapter 8.3.3 --- Real Data --- p.100 / Chapter 8.4 --- Discussion --- p.102 / Chapter 9 --- Conclusions and Future Research --- p.105 / Chapter 9.1 --- Conclusions --- p.105 / Chapter 9.2 --- Future Research --- p.106 / Bibliography --- p.108
34

Lingo – ein System zur automatischen Indexierung – Anwendung und Einsatzmöglichkeiten

Müller, Thomas 26 January 2011 (has links) (PDF)
Die heterogenen musealen Bestände (Text, Bild, gegenständliche Objekte) im Haus der Geschichte der Bundesrepublik Deutschland umfassen derzeit über 365.000 Objektbeschreibungen zeithistorischer Objekte. Auf der Basis des Open Source Indexierungssystems lingo wird eine automatische Indexierung entwickelt, die - aufsetzend auf den existierenden Rahmenbedingungen - normierte Beschreibungsmerkmale generiert und als Indexterme für das Retrieval zur Verfügung stellt. Zielvorstellung ist es, eine einheitliche Suche über die Objektbeschreibungen anhand der sprachlichen und semantischen Vereinheitlichung der Indexterme zu realisieren.
35

Child's play: activity recognition for monitoring children's developmental progress with augmented toys

Westeyn, Tracy Lee 20 May 2010 (has links)
The way in which infants play with objects can be indicative of their developmental progress and may serve as an early indicator for developmental delays. However, the observation of children interacting with toys for the purpose of quantitative analysis can be a difficult task. To better quantify how play may serve as an early indicator, researchers have conducted retrospective studies examining the differences in object play behaviors among infants. However, such studies require that researchers repeatedly inspect videos of play often at speeds much slower than real-time to indicate points of interest. The research presented in this dissertation examines whether a combination of sensors embedded within toys and automatic pattern recognition of object play behaviors can help expedite this process. For my dissertation, I developed the Child'sPlay system which uses augmented toys and statistical models to automatically provide quantitative measures of object play interactions, as well as, provide the PlayView interface to view annotated play data for later analysis. In this dissertation, I examine the hypothesis that sensors embedded in objects can provide sufficient data for automatic recognition of certain exploratory, relational, and functional object play behaviors in semi-naturalistic environments and that a continuum of recognition accuracy exists which allows automatic indexing to be useful for retrospective review. I designed several augmented toys and used them to collect object play data from more than fifty play sessions. I conducted pattern recognition experiments over this data to produce statistical models that automatically classify children's object play behaviors. In addition, I conducted a user study with twenty participants to determine if annotations automatically generated from these models help improve performance in retrospective review tasks. My results indicate that these statistical models increase user performance and decrease perceived effort when combined with the PlayView interface during retrospective review. The presence of high quality annotations are preferred by users and promotes an increase in the effective retrieval rates of object play behaviors.
36

Ranking de publicações baseado na extração de textos da Internet / Ranking of publications based on extraction of texts of the Internet

Oliveira, Henrique Przibisczki de 12 April 2009 (has links)
Orientador: Ricardo de Oliveira Anido / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-15T07:19:24Z (GMT). No. of bitstreams: 1 Oliveira_HenriquePrzibisczkide_M.pdf: 1997897 bytes, checksum: fce2bcda34e198778d87b8c87f83e484 (MD5) Previous issue date: 2009 / Resumo: Vários métodos de ranking atuais comparam os diversos veículos de publicação em relação à qualidade ou impacto. Esta informação é muito importante para que um pesquisador selecione veículos de renome para publicar suas pesquisas, ou mesmo, instituições podem promover seus pesquisadores baseando-se na qualidade dos veículos onde publicam. Esta informação sobre os veículos pode também ser valiosa para um governo destinar recursos 'as instituições ou uma empresa avaliar a qualidade de um candidato a um emprego. Existem várias métricas distintas para realizar ranking de veículos, mas o ponto comum entre a maioria é o uso de citações. Portanto, por mais que um veículo seja bastante prestigiado pelos pesquisadores, se ele não for indexado em uma base sua qualidade não será considerada. Este trabalho propõe um método para ranking de veículos de publicação obtendo as informações não de uma base de citações existente, mas de uma outra fonte de dados: a Web. As páginas dos professores de universidades são visitadas e delas são extraídas as suas publicações. De cada publicação é extraído o veículo e dessa forma, baseado nos veículos que um pesquisador quis exibir em sua página, os mesmos são ordenados. Este método irá contemplar veículos de publicação não existentes nas atuais bases de dados criando um novo ranking de publicações. Vários problemas computacionais interessantes são abordados neste trabalho: busca de informação na internet, segmentação textual, extração de componentes em uma referência bibliográfica e agrupamento / Abstract: Several current ranking methods compare different publication venues in relation to quality or impact. This information is very important for a researcher to choose renowned venues to publish his research. Institutes could promote their researchers based on the quality of places they have published. This information about the venues can also be valuable for a government to allocate resources to universities, or for companies to evaluate the quality of a candidate for a job. There are other distinct measures to perform a ranking of venues, but the idea in common among most of them is the use of citations. Therefore, despite the fact a venue is very prestigious for its researchers, if it is not indexed in a citation database, it will not be considered, since its "quality" cannot be measured. This work proposes to construct a ranking of publication venues obtaining the information not from a database, but from another data source: the Web. The university professor's webpages are visited to extract the publications. The venue is extracted from each publication, and thus, based on venues which a researcher wanted to show in his webpage, they are ranked. This method will include publication venues that do not exist in current databases, creating a new ranking of publications. Many interesting computational problems are discussed in this work: information search on the internet, text segmentation, extraction of components in a bibliographic citation, and clustering / Mestrado / Metodologia e Tecnicas da Computação / Mestre em Ciência da Computação
37

Automatic index generation for the free-text based database.

January 1992 (has links)
by Leung Chi Hong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 183-184). / Chapter Chapter one: --- Introduction --- p.1 / Chapter Chapter two: --- Background knowledge and linguistic approaches of automatic indexing --- p.5 / Chapter 2.1 --- Definition of index and indexing --- p.5 / Chapter 2.2 --- Indexing methods and problems --- p.7 / Chapter 2.3 --- Automatic indexing and human indexing --- p.8 / Chapter 2.4 --- Different approaches of automatic indexing --- p.10 / Chapter 2.5 --- Example of semantic approach --- p.11 / Chapter 2.6 --- Example of syntactic approach --- p.14 / Chapter 2.7 --- Comments on semantic and syntactic approaches --- p.18 / Chapter Chapter three: --- Rationale and methodology of automatic index generation --- p.19 / Chapter 3.1 --- Problems caused by natural language --- p.19 / Chapter 3.2 --- Usage of word frequencies --- p.20 / Chapter 3.3 --- Brief description of rationale --- p.24 / Chapter 3.4 --- Automatic index generation --- p.27 / Chapter 3.4.1 --- Training phase --- p.27 / Chapter 3.4.1.1 --- Selection of training documents --- p.28 / Chapter 3.4.1.2 --- Control and standardization of variants of words --- p.28 / Chapter 3.4.1.3 --- Calculation of associations between words and indexes --- p.30 / Chapter 3.4.1.4 --- Discarding false associations --- p.33 / Chapter 3.4.2 --- Indexing phase --- p.38 / Chapter 3.4.3 --- Example of automatic indexing --- p.41 / Chapter 3.5 --- Related researches --- p.44 / Chapter 3.6 --- Word diversity and its effect on automatic indexing --- p.46 / Chapter 3.7 --- Factors affecting performance of automatic indexing --- p.60 / Chapter 3.8 --- Application of semantic representation --- p.61 / Chapter 3.8.1 --- Problem of natural language --- p.61 / Chapter 3.8.2 --- Use of concept headings --- p.62 / Chapter 3.8.3 --- Example of using concept headings in automatic indexing --- p.65 / Chapter 3.8.4 --- Advantages of concept headings --- p.68 / Chapter 3.8.5 --- Disadvantages of concept headings --- p.69 / Chapter 3.9 --- Correctness prediction for proposed indexes --- p.78 / Chapter 3.9.1 --- Example of using index proposing rate --- p.80 / Chapter 3.10 --- Effect of subject matter on automatic indexing --- p.83 / Chapter 3.11 --- Comparison with other indexing methods --- p.85 / Chapter 3.12 --- Proposal for applying Chinese medical knowledge --- p.90 / Chapter Chapter four: --- Simulations of automatic index generation --- p.93 / Chapter 4.1 --- Training phase simulations --- p.93 / Chapter 4.1.1 --- Simulation of association calculation (word diversity uncontrolled) --- p.94 / Chapter 4.1.2 --- Simulation of association calculation (word diversity controlled) --- p.102 / Chapter 4.1.3 --- Simulation of discarding false associations --- p.107 / Chapter 4.2 --- Indexing phase simulation --- p.115 / Chapter 4.3 --- Simulation of using concept headings --- p.120 / Chapter 4.4 --- Simulation for testing performance of predicting index correctness --- p.125 / Chapter 4.5 --- Summary --- p.128 / Chapter Chapter five: --- Real case study in database of Chinese Medicinal Material Research Center --- p.130 / Chapter 5.1 --- Selection of real documents --- p.130 / Chapter 5.2 --- Case study one: Overall performance using real data --- p.132 / Chapter 5.2.1 --- Sample results of automatic indexing for real documents --- p.138 / Chapter 5.3 --- Case study two: Using multi-word terms --- p.148 / Chapter 5.4 --- Case study three: Using concept headings --- p.152 / Chapter 5.5 --- Case study four: Prediction of proposed index correctness --- p.156 / Chapter 5.6 --- Case study five: Use of (Σ ΔRij) Fi to determine false association --- p.159 / Chapter 5.7 --- Case study six: Effect of word diversity --- p.162 / Chapter 5.8 --- Summary --- p.166 / Chapter Chapter six: --- Conclusion --- p.168 / Appendix A: List of stopwords --- p.173 / Appendix B: Index terms used in case studies --- p.174 / References --- p.183
38

A Framework of Automatic Subject Term Assignment: An Indexing Conception-Based Approach

Chung, EunKyung 12 1900 (has links)
The purpose of dissertation is to examine whether the understandings of subject indexing processes conducted by human indexers have a positive impact on the effectiveness of automatic subject term assignment through text categorization (TC). More specifically, human indexers' subject indexing approaches or conceptions in conjunction with semantic sources were explored in the context of a typical scientific journal article data set. Based on the premise that subject indexing approaches or conceptions with semantic sources are important for automatic subject term assignment through TC, this study proposed an indexing conception-based framework. For the purpose of this study, three hypotheses were tested: 1) the effectiveness of semantic sources, 2) the effectiveness of an indexing conception-based framework, and 3) the effectiveness of each of three indexing conception-based approaches (the content-oriented, the document-oriented, and the domain-oriented approaches). The experiments were conducted using a support vector machine implementation in WEKA (Witten, & Frank, 2000). The experiment results pointed out that cited works, source title, and title were as effective as the full text, while keyword was found more effective than the full text. In addition, the findings showed that an indexing conception-based framework was more effective than the full text. Especially, the content-oriented and the document-oriented indexing approaches were found more effective than the full text. Among three indexing conception-based approaches, the content-oriented approach and the document-oriented approach were more effective than the domain-oriented approach. In other words, in the context of a typical scientific journal article data set, the objective contents and authors' intentions were more focused that the possible users' needs. The research findings of this study support that incorporation of human indexers' indexing approaches or conception in conjunction with semantic sources has a positive impact on the effectiveness of automatic subject term assignment.
39

Regensburger Verbundklassifikation und Schlagwortnormdatei im Tandem: Regensburger Verbundklassifikation und Schlagwortnormdatei imTandem

Probstmeyer, Judith 24 January 2011 (has links)
Im Katalog des Südwestverbunds besitzen zahlreiche Publikationen sowohl SWD-Schlagwörter und -ketten als auch Notationen der Regensburger Verbundklassifikation (RVK). An der Universitätsbibliothek Mannheim wurden auf dieser Datenbasis automatische Korrelationen zwischen SWD und RVK generiert, die im Rahmen einer Bachelorarbeit an der Hochschule der Medien Stuttgart analysiert wurden. Im Vortrag werden die Ergebnisse der Analyse vorgestellt und Überlegungen zu möglichen praktischen Anwendungen solcher Korrelationen angestellt.
40

Automatische Sacherschließung an der ZBW

Groß, Thomas 06 January 2012 (has links) (PDF)
Die ZBW möchte mit der Implementierung eines automatischen Sacherschließungsverfahrens einerseits dem Umstand einer stetigen Zunahme an Onlinedokumenten Rechnung tragen und andererseits bei der Inhaltserschließung neue Wege beschreiten. Neben der Entlastung der intellektuellen Erschließung durch ein semi- oder vollautomatisches Verfahren soll es darüber hinaus möglich sein, ZBW-fremde digitale Informationsressourcen jeglicher Art mit maschineller Hilfe zu indexieren und in einem gemeinsamen Suchraum auffindbar zu machen. Im derzeitigen Projekt werden hierzu die in der ZBW zur Anwendung kommenden Vokabulare (verbale Sacherschließung mit Standard-Thesaurus Wirtschaft, bzw. klassifikatorische Erschließung mit der Standardklassifikation Wirtschaft) für das maschinelle Verfahren angepasst, trainiert und evaluiert. Die Erfahrungen der ZBW mit der organisatorischen Implementierung automatischer Sacherschließung sowie die Möglichkeiten der Auswertung dieser Verfahren stehen im Mittelpunkt des Vortrages.

Page generated in 0.1874 seconds