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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.
101

Indexing consistency between online catalogues

Chen, Xu 23 May 2008 (has links)
In der globalen Online-Umgebung stellen viele bibliographische Dienstleistungen integrierten Zugang zu unterschiedlichen internetbasierten OPACs zur Verfügung. In solch einer Umgebung erwarten Benutzer mehr Übereinstimmungen innerhalb und zwischen den Systemen zu sehen. Zweck dieser Studie ist, die Indexierungskonsistenz zwischen Systemen zu untersuchen. Währenddessen werden einige Faktoren, die die Indexierungskonsistenz beeinflussen können, untersucht. Wichtigstes Ziel dieser Studie ist, die Gründe für die Inkonsistenzen herauszufinden, damit sinnvolle Vorschläge gemacht werden können, um die Indexierungskonsistenz zu verbessern. Eine Auswahl von 3307 Monographien wurde aus zwei chinesischen bibliographischen Katalogen gewählt. Nach Hooper’s Formel war die durchschnittliche Indexierungskonsistenz für Indexterme 64,2% und für Klassennummern 61,6%. Nach Rolling’s Formel war sie für Indexterme 70,7% und für Klassennummern 63,4%. Mehrere Faktoren, die die Indexierungskonsistenz beeinflussen, wurden untersucht: (1) Indexierungsbereite; (2) Indexierungsspezifizität; (3) Länge der Monographien; (4) Kategorie der Indexierungssprache; (5) Sachgebiet der Monographien; (6) Entwicklung von Disziplinen; (7) Struktur des Thesaurus oder der Klassifikation; (8) Erscheinungsjahr. Gründe für die Inkonsistenzen wurden ebenfalls analysiert. Die Analyse ergab: (1) den Indexieren mangelt es an Fachwissen, Vertrautheit mit den Indexierungssprachen und den Indexierungsregeln, so dass viele Inkonsistenzen verursacht wurden; (2) der Mangel an vereinheitlichten oder präzisen Regeln brachte ebenfalls Inkonsistenzen hervor; (3) verzögerte Überarbeitungen der Indexierungssprachen, Mangel an terminologischer Kontrolle, zu wenige Erläuterungen und "siehe auch" Referenzen, sowie die hohe semantische Freiheit bei der Auswahl von Deskriptoren oder Klassen, verursachten Inkonsistenzen. / In the global online environment, many bibliographic services provide integrated access to different web-based OPACs. In such an environment, users expect to see more consistency within and between systems. In practice, indexers are not always consistent with each other, because subject indexing is essentially a subjective process. The purpose of this study is to investigate the indexing consistency between systems and to find out whether it is still frustrated in the new networked environment. Meanwhile, some factors which may influence indexing consistency will be examined. The most important aim of this study is to find out the reasons for inconsistencies, so that some reasonable suggestions can be made to improve indexing consistency. A sample of 3,307 monographs, i.e. 6,614 records was drawn from two Chinese bibliographic catalogues. According to Hooper¡¯s formula, the average consistency for index terms was 64.2% and for class numbers 61.6%. According to Rolling¡¯s formula, for index terms it was 70.7%, for class numbers 63.4%. Several factors affecting indexing consistency were examined: (1) exhaustivity of indexing; (2) specificity; (3) length of monographs indexed; (4) category of indexing languages; (5) subject area of monographs indexed; (6) development of disciplines; (7) structure of vocabulary; (8) year of publication. The reasons for inconsistencies were also analyzed. The analysis revealed that: (1) indexers¡¯ lack of subject knowledge, their unfamiliarity with indexing languages and indexing rules led to a lot of inconsistencies; (2) the lack of unified or detailed indexing policies brought about inconsistencies as well; (3) delayed revision of indexing languages, lack of vocabulary control, shortage of scope notes and ¡°see also¡± reference notes, and high semantic freedom by term or class choosing also caused inconsistencies.
102

A leitura documentária de bibliotecários jurídicos : um estudo realizado a partir de aspectos da semiose e teoria da inferência observados na estrutura textual de doutrina /

Reis, Daniela Majorie Akama dos January 2019 (has links)
Orientadora: Mariângela Spotti Lopes Fujita / Banca: Carlos Cândido de Almeida / Banca: Franciele Marques Redigolo / Banca: Dulce Amélia de Brito Neves / Banca: Gercina Ângela Borém de Oliveira Lima / Resumo: A leitura documentária é realizada durante a análise de assunto, considerada a primeira etapa de vários processos, incluindo a indexação e a catalogação de assunto. Seu objetivo é desvendar o aboutness de documentos. Diversos são seus produtos, como termos extraídos de um documento para compor um índice (no caso da indexação) ou para compor registros bibliográficos em um catálogo (no caso da catalogação de assunto). Cada profissional que efetua a prática da leitura documentária é único e, como consequência disso, a análise do documento nunca ocorrerá da mesma forma. Vários fatores devem ser levados em conta, quando se estuda o processo de leitura documentária feito por profissionais da informação, como estratégias de leitura, conhecimento prévio, domínio de atuação e tipo de estrutura do documento analisado. O problema da pesquisa consiste na necessidade de avançar em estudos sobre processos metacognitivos, na leitura documentária de bibliotecários do domínio jurídico, utilizando teorias associadas à construção de significados. Aspectos que relacionam a semiótica à leitura viabilizaram a proposta de examinar a leitura documentária de livros do domínio jurídico, por meio de aspectos da teoria da inferência, especificamente os conceitos de abdução, dedução e indução. Com esses conceitos, busca-se mapear os processos mentais interpretativos dos profissionais nesse domínio, durante a leitura documentária. A coleta de dados foi realizada adotando-se a técnica introspectiva de Prot... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Documentary reading is performed during subject analysis, considered the first stage of various processes, including indexing and subject cataloging. It aims to unveil the aboutness of documents. Results in several products, such as terms extracted from a document to compose an index (in the case of indexing), or to compose bibliographic records in a catalog (in the case of subject cataloging). Each professional who performs the practice of documentary reading is unique, and as a consequence, the analysis of the document will never occur in the same way. Several factors should be considered when studying the process of documentary reading carried out by information professionals, such as reading strategies, previous knowledge, domain, and type of document structure analyzed. The problem consists in the need to advance in studies on metacognitive processes about the documentary reading of law librarians, using theories related to the construction of meaning. Aspects that relate semiotics to reading, enabled the proposal to examine the documentary reading of books in the legal domain through aspects of the inference theory, specifically the concepts of abduction, deduction and induction. With these concepts, we seek to map the interpretive mental processes of professionals in this field during documentary reading. The data collection was performed using the introspective technique of Individual Verbal Protocol, applied to law librarians. The data obtained was analyzed using cat... (Complete abstract click electronic access below) / Doutor
103

Continuous memories for representing sets of vectors and image collections / Mémoires continues représentant des ensembles de vecteurs et des collections d’images

Iscen, Ahmet 25 September 2017 (has links)
Cette thèse étudie l'indexation et le mécanisme d'expansion de requête en recherche d'image. L'indexation sacrifie la qualité de la recherche pour une plus grande efficacité; l'expansion de requête prend ce compromis dans l'autre sens : il améliore la qualité de la recherche avec un coût en complexité additionnel. Nous proposons des solutions pour les deux approches qui utilisent une représentation continue d'un ensemble de vecteurs. Pour l'indexation, notre solution est basée sur le test par groupe. Chaque vecteur image est assigné à un groupe, et chaque groupe est représenté par un seul vecteur. C'est la représentation continue de l'ensemble des vecteur du groupe. L'optimisation de cette représentation pour produire un bon test d'appartenance donne une solution basée sur la pseudo-inverse de Moore-Penrose. Elle montre des performances supérieures à celles d'une somme basique des vecteurs du groupe. Nous proposons aussi une alternative suivant au plus près les vecteurs-images de la base. Elle optimise conjointement l'assignation des vecteurs images à des groupes ainsi que la représentation vectorielle de ces groupes. La deuxième partie de la thèse étudie le mécanisme d'expansion de requête au moyen d'un graphe pondéré représentant les vecteurs images. Cela permet de retrouver des images similaires le long d'une même variété géométrique, mais éloignées en distance Euclidienne. Nous donnons une implémentation ultra-rapide de ce mécanisme en créant des représentations vectorielles incorporant la diffusion. Ainsi, le mécanisme d'expansion se réduit à un simple produit scalaire entre les représentations vectorielles lors de la requête. Les deux parties de la thèse fournissent une analyse théorique et un travail expérimental approfondi utilisant les protocoles et les jeux de données standards en recherche d'images. Les méthodes proposées ont des performances supérieures à l'état de l'art. / In this thesis, we study the indexing and query expansion problems in image retrieval. The former sacrifices the accuracy for efficiency, whereas the latter takes the opposite perspective and improves accuracy with additional cost. Our proposed solutions to both problems consist of utilizing continuous representations of a set of vectors. We turn our attention to indexing first, and follow the group testing scheme. We assign each dataset vector to a group, and represent each group with a single vector representation. We propose memory vectors, whose solution is optimized under the membership test hypothesis. The optimal solution for this problem is based on Moore-Penrose pseudo-inverse, and shows superior performance compared to basic sum pooling. We also provide a data-driven approach optimizing the assignment and representation jointly. The second half of the transcript focuses on the query expansion problem, representing a set of vectors with weighted graphs. This allows us to retrieve objects that lie on the same manifold, but further away in Euclidean space. We improve the efficiency of our technique even further, creating high-dimensional diffusion embeddings offline, so that they can be compared with a simple dot product in the query time. For both problems, we provide thorough experiments and analysis in well-known image retrieval benchmarks and show the improvements achieved by proposed methods.
104

A machine learning approach for plagiarism detection

Alsallal, M. January 2016 (has links)
Plagiarism detection is gaining increasing importance due to requirements for integrity in education. The existing research has investigated the problem of plagrarim detection with a varying degree of success. The literature revealed that there are two main methods for detecting plagiarism, namely extrinsic and intrinsic. This thesis has developed two novel approaches to address both of these methods. Firstly a novel extrinsic method for detecting plagiarism is proposed. The method is based on four well-known techniques namely Bag of Words (BOW), Latent Semantic Analysis (LSA), Stylometry and Support Vector Machines (SVM). The LSA application was fine-tuned to take in the stylometric features (most common words) in order to characterise the document authorship as described in chapter 4. The results revealed that LSA based stylometry has outperformed the traditional LSA application. Support vector machine based algorithms were used to perform the classification procedure in order to predict which author has written a particular book being tested. The proposed method has successfully addressed the limitations of semantic characteristics and identified the document source by assigning the book being tested to the right author in most cases. Secondly, the intrinsic detection method has relied on the use of the statistical properties of the most common words. LSA was applied in this method to a group of most common words (MCWs) to extract their usage patterns based on the transitivity property of LSA. The feature sets of the intrinsic model were based on the frequency of the most common words, their relative frequencies in series, and the deviation of these frequencies across all books for a particular author. The Intrinsic method aims to generate a model of author “style” by revealing a set of certain features of authorship. The model’s generation procedure focuses on just one author as an attempt to summarise aspects of an author’s style in a definitive and clear-cut manner. The thesis has also proposed a novel experimental methodology for testing the performance of both extrinsic and intrinsic methods for plagiarism detection. This methodology relies upon the CEN (Corpus of English Novels) training dataset, but divides that dataset up into training and test datasets in a novel manner. Both approaches have been evaluated using the well-known leave-one-out-cross-validation method. Results indicated that by integrating deep analysis (LSA) and Stylometric analysis, hidden changes can be identified whether or not a reference collection exists.
105

Automatic indexing of South African rock art images

Purshotam, Amrit January 2015 (has links)
A dissertation submitted for the degree of Master of Science School of Computer Science University of the Witwatersrand. Johannesburg, 2015. / Rock art is the archaeological term used to describe pre-historic artworks placed on natural stone and as one of the earliest known traces of modern human creativity, it is a major component of world history and human heritage. Archival records and the art itself, however, are rapidly decaying requiring the need to preserve them for future generations and humanity as a whole. In line with this, the Rock Art Research Institute digitised their collections of photographs and historical records of the rock art in southern Africa. This has resulted in the South African Rock Art Digital Archive, a collection of over 275 000 images of paintings depicting a wide variety of objects such as humans and animals. The problem with this archive, however, is that most of the images are not labelled with the objects that appear in them. Manual labelling is infeasible due to the size of the archive but rock art researchers require this information to perform text-based search queries. Therefore, in this research, we present the combination of the Viola Jones object detection framework and a Support Vector Machine to automatically classify rock art objects. To test it, we have created and assessed the performance of classi ers for eland, elephant, human, and rhebuck rock art objects. We have performed the experiments using ve-fold cross-validation and found the results to be promising considering the variation and deterioration of the paintings.
106

A theory of indexing : indexing theory as a model for information storage and retrieval /

Landry, Bertrand Clovis January 1971 (has links)
No description available.
107

Development of language analysis procedures with application to automatic indexing /

Young, Carol Elizabeth January 1973 (has links)
No description available.
108

Efficient Concurrent Operations in Spatial Databases

Dai, Jing 16 November 2009 (has links)
As demanded by applications such as GIS, CAD, ecology analysis, and space research, efficient spatial data access methods have attracted much research. Especially, moving object management and continuous spatial queries are becoming highlighted in the spatial database area. However, most of the existing spatial query processing approaches were designed for single-user environments, which may not ensure correctness and data consistency in multiple-user environments. This research focuses on designing efficient concurrent operations on spatial datasets. Current multidimensional data access methods can be categorized into two types: 1) pure multidimensional indexing structures such as the R-tree family and grid file; 2) linear spatial access methods, represented by the Space-Filling Curve (SFC) combined with B-trees. Concurrency control protocols have been designed for some pure multidimensional indexing structures, but none of them is suitable for variants of R-trees with object clipping, which are efficient in searching. On the other hand, there is no concurrency control protocol designed for linear spatial indexing structures, where the one-dimensional concurrency control protocols cannot be directly applied. Furthermore, the recently designed query processing approaches for moving objects have not been protected by any efficient concurrency control protocols. In this research, solutions for efficient concurrent access frameworks on both types of spatial indexing structures are provided, as well as for continuous query processing on moving objects, for multiple-user environments. These concurrent access frameworks can satisfy the concurrency control requirements, while providing outstanding performance for concurrent queries. Major contributions of this research include: (1) a new efficient spatial indexing approach with object clipping technique, ZR+-tree, that outperforms R-tree and R+-tree on searching; (2) a concurrency control protocol, GLIP, to provide high throughput and phantom update protection on spatial indexing with object clipping; (3) efficient concurrent operations for indices based on linear spatial access methods, which form up the CLAM protocol; (4) efficient concurrent continuous query processing on moving objects for both R-tree-based and linear spatial indexing frameworks; (5) a generic access framework, Disposable Index, for optimal location update and parallel search. / Ph. D.
109

Augmenting expertise: Toward computer-enhanced clinical comprehension

Cohen, Trevor January 2007 (has links)
Cognitive studies of clinical comprehension reveal that expert clinicians are distinguished by their superior ability to recognize meaningful patterns of data in clinical narratives. For example, in psychiatry, the findings of hallucinations and delusions suggest the subdiagnostic hypothesis of a psychotic episode, which in turn suggests several diagnoses, including schizophrenia. This dissertation describes the design and evaluation of a system that aims to simulate an important aspect of expert comprehension: the ability to recognize clusters of findings that support sub-diagnostic hypotheses. The broad range of content in psychiatric narrative presents a formidable barrier to achieving this goal, as it contains general concepts and descriptions of the subjective experience of psychiatric patients in addition to general medical and psychiatric concepts. Lexically driven language processing of such narrative would require the exhaustive predefinition of every concept likely to be encountered. In contrast, Latent Semantic Analysis (LSA) is a corpus-based statistical model of language that learns human-like estimates of the similarity between concepts from a text corpus. LSA is adapted to create trainable models of sub-diagnostic hypotheses, which are then used to recognize related elements in psychiatric discharge summary text. The system is evaluated against an independently annotated set of psychiatric discharge summaries. System-rater agreement approached rater-rater agreement, providing support for the practical application of vector-based models of meaning in domains with broad conceptual territory. Other applications and implications are discussed, including the presentation of a prototype user interface designed to enhance novice comprehension of psychiatric discourse.
110

Index-based Graph Querying and Matching in Large Graphs

Zhang, Shijie 03 March 2010 (has links)
No description available.

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