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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.
151

Recuperação de informação com realimentação de relevância apoiada em visualização / Information retrieval with relevance feedback on supported display

Melo, Diogo Oliveira de 16 April 2014 (has links)
A mineração de grandes coleções de textos, imagens e outros tipos de documentos tem se mostrado uma forma efetiva para exploração e interação com grandes quantidades de informações disponíveis, principalmente na World Wide Web. Neste contexto, diversos trabalhos têm tratado de mineração tanto de coleções estáticas quanto de coleções dinâmicas de objetos. Adicionalmente, técnicas de visualização têm sido propostas para auxiliar o processo de entendimento e de exploração dessas coleções, permitindo que a interação do usuário melhore o processo de mineração (user in the loop). No caso específico de dados dinâmicos, foi desenvolvido por Roberto Pinho e colegas uma técnica incremental (IncBoard) com o objetivo de visualizar coleções dinâmicas de elementos. Tal técnica posiciona os elementos em um grid bidimensional baseado na similaridade de conteúdo entre os elementos. Procura-se manter elementos similares próximos no grid. A técnica foi avaliada em um processo que simulava a chegada de novos dados, apresentando iterativamente novos elementos a serem posicionados no mapa corrente. Observa-se, entretanto, que um aspecto importante de tal ferramenta seria a possibilidade de novos elementos - a serem exibidos no mapa, mantendo coerência com o mapa corrente - serem selecionados a partir do interesse demonstrado pelo usuário. Realimentação de relevância tem se mostrado muito efetiva na melhoria da acurácia do processo de recuperação. Entretanto, um problema ainda em aberto é como utilizar técnicas de realimentação de relevância em conjunto com exploração visual no processo de recuperação de informação. Neste trabalho, é investigado o desenvolvimento de técnicas de exploração visual utilizando realimentação de relevância para sistemas de recuperação de informação de domínio específico. O Amuzi, um sistema de busca de músicas, foi desenvolvido como uma prova de conceito para a abordagem investigada. Dados coletados da utilização do Amuzi, por usuários, sugerem que a combinação de tais técnicas oferece vantagens, quando utilizadas em determinados domínios. Nesta dissertação, a recuperação de informação com realimentação de relevância apoiada em visualização, bem como o sistema Amuzi são descritos. Também são analisados os registros de utilização dos usuários / The mining of large text collections, images and other types of digital objects has shown to be a very effective way to explore and interact with big data, specially on the World Wide Web. On that subject, many researchers have been done on data mining of static and dynamic collections. Moreover, data visualization techniques have been proposed to aid on the understanding and exploration of such data collections, also allowing users to interact with data, user in the loop. On the speciific subject of dynamic data, Roberto Pinho and colleagues have developed an incremental technique, called Inc-Board, which aims to visualize dynamic data collections. IncBoard displays the documents on a two dimensional grid in a way that similar elements tends to be close to each other. This technique was evaluated in a process that simulated the arrival of new data elements, iteratively inserting new elements on the grid. Nonetheless, it would be useful if the user could interact with such documents to point out which are relevant and which are not relevant to his/her search. Relevance Feedback has also shown to be effective on improving the accuracy of Information Retrieval techniques. An issue that still open is how to combine data visualization and Relevance Feedback to improve Information Retrieval. On this dissertation, the development of techniques with data visualization and Relevance Feedback are investigated to aid on the Information Retrieval task, for specific domains. Amuzi is an Information Retrieval system, built to be a proof of concept for the investigated approach. Data collected from the usage of the system suggests that combining such techniques may outperform traditional Information Retrieval systems when applied for specifc domains. This dissertation has the description the information retrieval process with feedback relevance supported by visualization and the Amuzi system. Usage log are processed and analyzed to evaluate the investigated approach
152

Métodos estatísticos para a análise de dados de cDNA microarray em um ambiente computacional integrado / Statistical methods for cDNA microarray data analysis in an integrated computational environment

Esteves, Gustavo Henrique 23 March 2007 (has links)
Análise de expressão gênica em larga escala é de fundamental importância para a biologia molecular atual pois possibilita a medida dos níveis de expressão de milhares de genes simultaneamente, o que torna viável a realização de trabalhos voltados para biologia de sistemas (systems biology). Dentre as principais técnicas experimentais disponíveis para esta finalidade, a tecnologia de microarray tem sido amplamente utilizada. Este procedimento para medida de expressão gênica é bastante complexo e os dados obtidos são freqüentemente observacionais, o que dificulta a modelagem estatística. Não existe um protocolo padrão para a geração e avaliação desses dados, sendo portanto necessário buscar procedimentos de análise que sejam adequados para cada caso. Assim, os principais métodos matemáticos e estatísticos aplicados para a análise desses dados deveriam estar disponíveis de uma forma organizada, coerente e simples em um ambiente computacional que confira robustez, confiabilidade e reprodutibilidade às análises realizadas. Uma forma de garantir estas características é através da representação (e documentação) de todos os algoritmos utilizados na forma de um grafo direcionado e acíclico que descreva todo o conjunto de transformações, ou operações, aplicadas seqüencialmente ao conjunto de dados. De acordo com esta filosofia, um ambiente foi implementado neste trabalho incorporando diversos procedimentos disponíveis na literatura atual, além de outros que foram aprimorados ou propostos nesta tese. Dentre os métodos de análise já disponíveis que foram incorporados destacam-se aqueles para a construção de agrupamentos, busca de genes diferencialmente expressos e classificadores, construção de redes de relevância e classificação funcional de grupos gênicos. Além disso, o método de construção de redes de relevância foi revisto e aprimorado e um modelo estatístico para a classificação funcional de redes de regulação gênica foi proposto e implementado. Esses dois últimos métodos surgiram a partir de problemas biológicos para os quais não existiam procedimentos de análise adequados na literatura. Finalmente, são apresentados dois conjuntos de dados que foram analisados utilizando diversas ferramentas disponíveis neste ambiente computacional. / High throughput gene expression analysis has a great importance to molecular biology nowadays because it can measure expression profiles for hundreds of genes, and this turn possible studies focused in systems biology. Between the main experimental techniques available in this direction, the microarray technology has been widely used. This experimental procedure to quantify gene expression profiles is very complex and the data obtained is frequently observational, what difficult the statistical modelling. There is not a standard protocol for the generation and evaluation of microarray data, therefore it is necessary to search by adequate analysis methods for each case. Thus, the main mathematical and statistical methods applied to microarray data analysis would have to be available in an organized, coherent and simple way in a computational environment that confer robustness, reliability and reproducibility to the data analysis. One way to guarantee these characteristics is through the representation (and documentation) of all used algorithms as a directed and acyclic graph that describes the set of transformations, or operations, applied sequentially to the dataset. According to this philosophy, an environment was implemented in this work aggregating several data analysis procedures already available in the literature, beyond other methods that were improved or proposed in this thesis. Between the procedures already available that were incorporated we can distinguish that ones for cluster analysis, differentially expressed genes and classifiers search, construction of relevance networks and functional classification of gene groups. Moreover, the method for construction of relevance networks was revised and improved and an statistical model was proposed and implemented for the functional classification of gene regulation networks. The last two procedures was born from biological problems for which adequate data analysis methods didn?t exist in the literature. Finally, we presented two datasets that were evaluated using several data analysis procedures available in this computational environment.
153

An Interactive Research Approach to the Triple Helix Model in Environmental Science

Rosenlund, Joacim January 2015 (has links)
Increased interaction between scientists and the social environment is considered to be one of the characteristics of modern science. This interaction can occur through collaboration between different sectors in society. In connection to this, the Triple Helix model claims that interaction between university, industry and public sectors, is key to modern innovation development. So far, cross-sector interaction between actors in environmental science has been scarcely studied in a scientific manner. Most studies carried out in the area have disregarded the actual practice of such collaborations and what happens in projects where these sectors interact. As this has become a common way to solve environmental problems, it is of considerable importance to gain more knowledge about this process. The objective of this research was to study and explain cross-sector collaboration. Using the interactive research method, characterised by joint learning and interaction with the participants, this was explored through two case studies. The method was well suited for studying ongoing interactions between the university, industry and public sectors. The first case was an international collaboration between representatives of the Triple Helix sectors. Here, olive-mill wastewater in Greece was the focus. The Triple Helix framework was used both on the intended analytical level and at a management level closer to the actor level of the participants. The second case was a three-year environmental research project in the Kalmar region where strong university-industry collaboration was carried out in order to find wastewater treatment solutions in the wood industry. This collaboration was extended to include more actors in the region during the process. The actual practice of these cases showed the importance of a dialogue between participants. Triple Helix can be used as an initial framework for such a dialogue through which the model is redefined by input from all sectors.
154

Jornalismo e relevância : o discurso dos leitores dos jornais de referência no Facebook

Dalmaso, Silvana Copetti January 2017 (has links)
Esta pesquisa mapeia, analisa e problematiza as noções que os leitores mobilizam para avaliar a relevância jornalística nas publicações dos jornais brasileiros de referência no Facebook. Por meio da metodologia da Análise do Discurso, foram examinados 59.786 comentários de 211 publicações dos jornais Folha de S.Paulo, O Estado de S.Paulo e O Globo, no período de abril de 2016. A análise resultou em quatro indicadores de relevância utilizados pelos leitores: o interesse individual, a atribuição de importância, a novidade e a atribuição de qualidade. No interesse individual, os leitores vincularam a relevância das notícias à satisfação de interesses pessoais, se autorreferenciando como critério. A atribuição de importância foi dividida em três sentidos: a rejeição ao não importante, às notícias que os sujeitos consideraram inúteis ou fúteis; a indicação do que é mais importante de acordo com a hierarquização e opinião próprias do leitor; e a contestação dos enquadramentos, questionando os tipos de informações destacadas nas notícias. A falta de novidade foi indicada como um valor associado à relevância, pois o novo é uma expectativa da audiência em relação ao jornalismo. E a atribuição de qualidade pôde ser inferida por meio das deficiências apontadas, como informações erradas e falta de isenção e pluralidade. A análise ainda verificou que os sujeitos percebem algumas lógicas do ambiente digital, como o maior número de fontes de informação, a restrição de acesso nos websites dos jornais, a leitura somente dos títulos das notícias e a consciência da economia do clique. Por último, foram identificadas situações de conversação entre os leitores relacionadas ao interesse (pessoal e dos outros) e à relevância das notícias de entretenimento. A partir do levantamento teórico associado à análise dos comentários, concluímos que a relevância é construída subjetivamente pelos leitores, a partir de posições sociais e ideológicas, que consideram parâmetros próprios de interesse e parâmetros aprendidos da prática de leitura do jornalismo. Esses leitores mobilizam graus diferenciados de importância, relacionando-a com a novidade e a qualidade jornalística, e estão circundados por lógicas conectivas, interativas e informativas das redes sociais. / This research maps, analyzes and problematizes the notions that readers mobilize when evaluating the journalistic relevance of posts by reference Brazilian newspapers on Facebook. Using the methodology of Discourse Analysis, 59,780 comments were analyzed on 211 posts by the newspapers Folha de S. Paulo, O Estado de S. Paulo and O Globo, during April 2016. The analysis resulted in four indicators of relevance used by the readers: individual interest, attribution of importance, novelty and attribution of quality. Under individual interest, the readers linked the relevance of the news to the satisfaction of personal interests, taking self-referencing as the criterion. Attribution of importance was divided into three senses: rejection of the non-important, of news that the subjects consider useless or futile; indication of what is most important according to the reader's own opinion and hierarchization; and contestation of frameworks, questioning the types of information highlighted in the news. The lack of novelty was indicated as a value associated to relevance, since new is an expectation by the audience in relation to journalism. Attribution of quality was inferred from the deficiencies pointed out, such as misinformation and lack of exemption and plurality. The analysis also verified that the subjects perceive some of the logics of the digital environment, such as the increase of information sources, websites with restricted access of the newspapers, reading headlights only and the consciousness of click economy. Lastly, conversational situations between readers were identified regarding interest (personal and of others) and also regarding the relevance of entertainment news. From the theoretical survey associated to the analysis of the comments, we have concluded that relevance is constructed subjectively by readers, from social and ideological positions, who consider personal parameters of interest and parameters learned through the practice of journalistic reading. Readers mobilize different degrees of importance, relating it to novelty and journalistic quality, and are surrounded by connective, interactive and informative logics of social networks.
155

The Relevance of Citations : a case of study of stratospheric ozone monitoring

Philipson, Joakim January 1996 (has links)
A contextual citation analysis was performed on a sample of 68 articles citing either or both oftwo key papers from the research field of stratospheric ozone monitoring.The theoretical approach of each article was assessed as either chemical or dynamical, or wasleft unspecified. Functions of citations to the two key papers were classified into 13 categories,seen to express various kinds of relevance relationships. Topical relatedness between citedand citing articles was studied in terms of number of shared descriptors and the union overlapmeasure. A certain theory~dependence, in the sense of a relatively high degree of correspondence between the theoretical approach of citing and cited articles, was observed in the material. The correlation between topical relatedness and citation relationships appeared to beweak.
156

Query Expansion : en jämförande studie av Automatisk Query Expansion med och utan relevans-feedback / Query Expansion : a comparative study of Automatic Query Expansion with and without relevance feedback

Ekberg-Selander, Karin, Enberg, Johanna January 2007 (has links)
In query expansion (QE) terms are added to an initial query in order to improve retrieval effectiveness. In this thesis we use QE in the sense that a reformulation of the query is done by deleting the terms in the initial query and instead replacing them with terms from the documents retrieved in the initial run. The aim of this thesis is to, in a experimental full text invironment, study and compare the retrieval result of two different query expansion strategies in relation to each other. The following questions are addressed by the study: How do the two strategies perform in relation to each other regarding recall?What may be causing the result?Are the two strategies retrieving the same relevant documents?Two strategies are designed to simulate a searcher using automatic query expansion (AQE) either with or without relevance feedback. Strategy I is simulating AQE without relevance feedback by taking the top five documents that are retrieved in the initial run and then extracting the top ten most frequently occurring terms in these to create a new query. Correspondingly the Strategy II, is simulating AQE with relevance feedback by taking the top five relevant documents and extracting the top ten terms in these to create a new query. It is concluded that both of the strategies’ retrieval performance was improved for most of the topics. In average Strategy II did achieve 54.63 percent recall compared to Strategy I which did achieve 45.59 percent recall. The two strategies did retrieve different relevant documents for majority of the topics. Hence, it would be reasonable to base a system on both of them. / Uppsatsnivå: D
157

Organisation capital empirical construct in the UK : methodology, validity, value relevance and pricing

Abduvaliyev, Davlatbek January 2014 (has links)
The existing literature proposes a broad spectrum of methodologies to measure firm's superior operating capabilities, referring to them under different names such as 'knowledge assets', 'intellectual capital', 'organisation capital', etc. Through the work reported in this thesis, I intend to contribute to the research field by exploring one specific measure of a firm's operating capabilities proposed by Lev, Radhakrishnan and Zhang (Abacus, 2009). These researchers empirically construct an organisation capital measure and argue it has predictive ability for future performance and is able to explain future abnormal stock returns in the USA. I extend their research to the UK. In doing so, I also critically discuss the organisation capital estimation process and propose potential improvements to the technique. I find evidence of its construct validity in the UK. I examine the organisation capital measure's predictive ability for future performance. The results suggest that this measure is positively associated with future sales growth in the UK. Additionally, the organisation capital measure seems to explain persistence of the operating income and sales of firms in the UK. Via value relevance tests, I obtain empirical evidence that the organisation capital measure is positively associated with equity market value in the UK. Moreover, it is positively associated with the earnings multiplier in value relevance tests. This finding is consistent with empirical evidence that the organisation capital measure is positively associated with one-year ahead earnings and positively affects earnings persistence in such an association in the UK. Finally, I fail to find evidence of the organisation capital measure's ability to explain future excess stock returns in the UK. This suggests that information on firm-specific operating capabilities captured by the organisation capital measure is recognised by the capital market participants and contemporaneously incorporated into stock prices. This result, however, contrasts with the Lev et al. (2009) findings in the USA that organisation capital is mispriced.
158

Think Piece : conceptions of quality and ‘Learning as Connection’: teaching for relevance

Lotz-Sisitka, Heila 1965- January 2013 (has links)
This think piece captures some of the thinking that emerged in and through the Southern African Development Community (SADC) Regional Environmental Education Programme research programme. This research programme emerged over a five-year period (2008–2012) and involved ten southern African teacher education institutions from eight countries (see ‘Acknowledgements’). The research programme sought to understand what contributions environment and sustainability education could make to debates on educational quality and relevance. Issues of educational quality are high on the national agendas of governments in southern Africa, as it is now well known that providing access to schooling is not a sufficient condition for achieving educational quality. Educational quality is intimately linked to the processes of teaching and learning, but the concept of educational quality is not unproblematic in and of itself. It is, as Noel Gough (2005) noted many years ago, an ‘order word’ that shapes the way people think and practise. Our enquiries during this research programme involved a number of case studies (that were reported on in the Southern African Journal of Environmental Education (SAJEE) in 2008, and are again reported on in this edition of the SAJEE), but the programme also involved theoretical engagement with the concept of educational quality and relevance. This think piece helps to make some of this thinking and theoretical deliberation visible. The author of this think piece was also the leader of the regional research programme and was tasked with synthesising the theoretical deliberations that emerged from the research design which were found to be useful for guiding interpretations and deliberation on more detailed case studies undertaken at country level.
159

Modelo social de relevância para opiniões. / S.O.R.M.: Social Opinion Relevance Model.

Allan Diego Silva Lima 02 October 2014 (has links)
Esta tese apresenta um modelo de relevância de opinião genérico e independente de domínio para usuários de Redes Sociais. O Social Opinion Relevance Model (SORM) é capaz de estimar a relevância de uma opinião com base em doze parâmetros distintos. Comparado com outros modelos, a principal característica que distingue o SORM é a sua capacidade para fornecer resultados personalizados de relevância de uma opinião, de acordo com o perfil da pessoa para a qual ela está sendo estimada. Devido à falta de corpus de relevância de opiniões capazes de testar corretamente o SORM, fez-se necessária a criação de um novo corpus chamado Social Opinion Relevance Corpus (SORC). Usando o SORC, foram realizados experimentos no domínio de jogos eletrônicos que ilustram a importância da personalização da relevância para alcançar melhores resultados, baseados em métricas típicas de Recuperação de Informação. Também foi realizado um teste de significância estatística que reforça e confirma as vantagens que o SORM oferece. / This thesis presents a generic and domain independent opinion relevance model for Social Network users. The Social Opinion Relevance Model (SORM) is able to estimate an opinions relevance based on twelve different parameters. Compared to other models, SORMs main distinction is its ability to provide customized results, according to whom the opinion relevance is being estimated for. Due to the lack of opinion relevance corpora that are able to properly test our model, we have created a new one called Social Opinion Relevance Corpus (SORC). Using SORC, we carried out some experiments on the Electronic Games domain that illustrate the importance of customizing opinion relevance in order to achieve better results, based on typical Information Retrieval metrics, such as NDCG, QMeasure and MAP. We also performed a statistical significance test that reinforces and corroborates the advantages that SORM offers.
160

The interaction between visual resolution and task-relevance in guiding visual selective attention

Peterson, Jared Joel January 1900 (has links)
Doctor of Philosophy / Department of Psychological Sciences / Lester C. Loschky / Visual resolution (i.e., blur or clarity) is a natural aspect of vision. It has been used by film makers to direct their audience’s attention by focusing the depth of field such that the critical region in a scene is uniquely clear and the surrounding is blurred. Resolution contrast can focus attention towards unique clarity, as supported by previous eye tracking and visual search research (Enns & MacDonald, 2013; Kosara, Miksch, Hauser, Schrammel, Giller, & Tscheligi, 2002; & McConkie, 2002; Peterson, 2016; Smith & Tadmor, 2012). However, little is known about how unique blur is involved in guiding attention (e.g., capture, repel, or be ignored). Peterson (2016) provided reaction time (RT) evidence that blur is ignored by selective attention when resolution is not task-relevant. Perhaps visual resolution is a search asymmetry where unique clarity can be used to guide selective attention during search, but unique blur cannot guide attention. Yet, perhaps the RT evidence was not sensitive enough with Peterson’s (2016) methodology to observe unique blur capturing or repelling attention. Eye movements (e.g., letter first fixated) may be more sensitive than RT as it measures blur and clarity’s influence on guiding attention earlier in a trial. The current study conducted three experiments that investigated: a) how visual resolution guides attention when it is task-irrelevant (Exp. 1), b) whether visual resolution is a search asymmetry, by manipulating resolution’s task-relevance (Use Blur, Use Clarity, Do Not Use Unique Blur or Clarity, & No Instructions) (Exp. 2), and c) whether blur and/or clarity are processed preattentively or require attention (Exp. 3). Experiments 1 and 2 manipulated blur and clarity (Exp. 1 Resolution = Task-irrelevant & Exp. 2 Resolution = Task-relevant), during a rotated L and T visual search measuring RT and eye movements. Experiment 1 found with the more sensitive eye movement measures that unique clarity strongly captured attention while unique blur weakly repelled attention towards nearby clarity (or clarity, especially that close to blur, captured attention). Experiment 2 found evidence that visual resolution is not a search asymmetry because the influence of resolution on selective attention was contingent upon its task-relevance, which theoretically supports the presence of a reconfigurable resolution feature detector. Experiment 3 used a feature search for either blur or clarity (i.e., resolution was task-relevant) and compared RT x Set Size search slopes. Both blurred and clear target present RT x Set Size search slopes were ~ 1 msec/item. The results strongly supported that blur and clarity are both processed preattentively, and provided additional evidence that resolution is not a search asymmetry. Overall, the current studies shed light on how visual resolution is processed and guides selective attention. The results revealed that visual resolution is processed preattentively and has a dynamic relationship with selective attention. Predicting how resolution will guide attention requires knowledge of whether resolution is task relevant or irrelevant. By increasing our understanding of how resolution contrast guides attention, we can potentially apply this knowledge to direct viewers’ attention more efficient using computer screens and heads-up displays.

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