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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.
31

Analyse des réseaux sociaux : vers une adaptation de la navigation sociale / Social network analysis : towards an adaptation of social networks

Mezghani, Manel 29 September 2015 (has links)
L'avènement du web 2.0, centré utilisateur, a fait émerger une quantité importante d'informations (personnelles, collectives, partagées, "aimées", etc.). Ces informations peuvent constituer une aide pour les utilisateurs en les guidant vers l'information recherchée. Cependant, cette quantité rend l'accès à l'information partagée de plus en plus difficile, vu la diversité des contenus qui peuvent intéresser l'utilisateur. La désorientation de l'utilisateur est donc l'un des principaux problèmes liés aux médias sociaux. Pour surmonter ce problème, l'adaptation constitue une solution classique qui peut être appliquée dans un contexte social. Avec l'évolution des réseaux sociaux, de nouvelles notions apparaissent comme la navigation sociale, qui est une manière de naviguer en étant influencé par les autres utilisateurs du réseau. Une autre notion importante est celle de "tag". Ce terme définit les annotations sociales créées par les utilisateurs et associées à des ressources. La navigation peut être dès lors effectuée aussi bien par les liens qu'à travers les tags. Adapter la navigation sociale, signifie la rendre plus ciblée pour chaque utilisateur selon ses intérêts. Concrètement, cela peut se faire en recommandant à chaque utilisateur des tags, qu'il pourra suivre ou non. Pour cela, il faut garantir une détection adéquate des intérêts de l'utilisateur ainsi que la prise en compte de leur évolution. Cependant, nous sommes confrontés à des limites liées à : i) la détection des intérêts, puisque ces derniers peuvent être déduits de plusieurs ressources sociales (des amis, des ressources, des tags, etc.). Leur pertinence est primordiale afin de garantir un résultat d'adaptation adéquat. ii) la mise à jour du profil utilisateur. En effet, l'utilisateur social, est caractérisé par sa grande activité sociale, et par conséquent ses intérêts doivent refléter ses "vrais" intérêts à chaque période de temps afin d'aboutir à une adaptation fiable. Afin de résoudre les problèmes affectant la qualité d'adaptation de la navigation sociale cités ci-dessus, nous avons proposé en premier lieu, une approche de détection des intérêts de l'utilisateur. Cette approche analyse les tags des utilisateurs selon le contenu de leurs ressources respectives. La plupart des recherches ne considèrent pas l'exactitude des tags vis-à-vis du contenu des ressources : cette exactitude reflète si l'utilisateur peut vraiment être intéressé par le contenu ou pas. Les tags précis sont ceux qui reflètent fidèlement le contenu des ressources. Ceci est effectué grâce à l'interrogation du réseau de l'utilisateur et de l'analyse de son comportement d'annotation. Notre approche repose sur l'hypothèse qu'un utilisateur qui annote la ressource par des tags reflétant le contenu de ladite ressource, reflète mieux ses "vrais" intérêts. Nous avons proposé en deuxième lieu, une approche de mise à jour des intérêts des utilisateurs. Nous nous sommes intéressés aux techniques d'enrichissement du profil utilisateur est effectué par l'ajout des intérêts jugés pertinents à un moment donné. L'enrichissement dans un contexte social est effectué selon l'information sociale comme les personnes proches qui partagent avec l'utilisateur des comportements en communs, selon le comportement d'annotation des utilisateurs, et selon les métadonnées des ressources annotées. Le choix de ces informations est effectué selon l'étude de leur influence sur l'évolution des intérêts de l'utilisateur. L'approche d'enrichissement nous a servi à proposer des recommandations (de tags) selon les nouveaux tags ajoutés au profil utilisateur.Ces deux contributions ont été testées sur la base sociale Delicious. Elles ont montré un taux de précision assez important. Elles ont aussi prouvé leur efficacité par rapport à des méthodes classiques. De plus, le taux d'ambigüité associé aux tags a été fortement réduit, grâce au filtrage implicite des tags non pertinents par rapport au contenu des ressources. / The advent of Web 2.0, user-centered, has given rise to a significant amount of information (personal, collective, shared, "loved", etc.). This information is a way to help users and guide them to the information sought. However, this quantity makes access to shared information more and more difficult, given the diversity of content that may interest the user. Disorientation of the user is one of the main problems related to social media. To overcome such problem, adaptation is a standard solution that can be applied in a social context. With the evolution of these social networks, new concepts appear such as social navigation, which is a way to navigate while being influenced by other users in the network: Another important concept is that of "tag". This term is defined as social annotations created by users and associated to resources. Navigation can be therefore carried out by both links and tags. Adapting social navigation means making it more targeted for each user according to their interests. In practice, this can be done by recommending tags to each user, so he can follow or not. To adapt the social navigation, we must ensure proper detection of the user's interests and taking into account their evolution. However, we are faced with some problems: i) the detection of interest, since they can be derived from several social resources (friends, resources, tags, etc.). Their relevance is primordial to ensure adequate adaptation result. ii) updating the user profile. Indeed, the social user, is characterized by its great social activity, and therefore its interests should reflect its "real" interest each time period in order to achieve a reliable adaptation. To solve the problems affecting the quality of adaptation of social navigation quoted above, we first proposed a method for detecting the user's interests. This proposal aims to overcome the detection of irrelevant interests issues. This approach analyzes the user tags depending on the content of their respective resources. Unlike most research, who do not consider the accuracy of tags with the contents of resource, the accuracy reflects whether the user is really interested with the content or not. This is done by querying the user's network and analysis of the user annotation behavior. The approach is based on the assumption that a user annotates the resource by tags reflecting the content of this resource better reflects its "true" interests. Following the proposal of the interests of detection approach, we conducted second, the treatment of the problem of updating these interests. We were interested to the user profile enrichment techniques, performed by adding interests deemed relevant at a given time. The enrichment in a social context is performed according to social information such as neighbours who share the user behaviors in common, according to the user annotation behavior, and according to the metadata annotated resources. The choice of such information shall follow the study of their influence on the changing interests of the user. The approach we used enrichment propose recommendations (tags) according to the new tags added to the user profile. Both contributions were tested on the social database Delicious. They showed a sizeable accuracy rate. They have also proven their efficiency compared to conventional methods. In addition, the rate of ambiguity associated with the tags has been greatly reduced, thanks to the implicit filtering of irrelevant tags relative to resource content.
32

Análise da penetração de material resinoso ao esmalte dental em função de agente clareador e tempo

Machado, Jeferson da Silva [UNESP] 02 March 2004 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-03-02Bitstream added on 2014-06-13T19:30:40Z : No. of bitstreams: 1 machado_js_me_arafo.pdf: 2259964 bytes, checksum: 7e24645a8db75d3219fc3b67c94f8d3a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve por finalidade analisar a influência do tempo de espera sobre a adaptação e capacidade de penetração de materiais resinosos sobre o esmalte dental submetido ao tratamento clareador através de dois diferentes agentes clareadores, ou sejam: Peróxido de Carbamida 16% (Clarigel Gold - Dentsply) e Peróxido de Hidrogênio 38%(Opalescence X-tra Boost - Ultradent) .Assim, quarenta e oito pré-molares hígidos foram divididos em dois grupos de acordo com o agente clareador a ser utilizado, sendo, cada grupo subdividido em 4 sub-grupos com 6 espécimes de acordo com o tempo de espera para aplicação do material resinoso após o término do tratamento clareador : restauração imediata; 7dias; 14 dias e 30 dias. Após a conclusão do tratamento clareador a análise da adaptação da resina composta foi observada através de microscopia óptica comum sob luz polarizada, em aumento de 200x sendo que, a avaliação da penetração dos prolongamentos resinosos em esmalte dental em aumento de 400x. Os resultados obtidos foram submetidos à análise estatística, sendo que, os dados originais foram transformados em médias proporcionais dos comprimentos dos tags do Grupo Controle e dos Grupos experimentais transformados em arcoseno. Assim, foi realizada Análise de Variância que indicou uma diferença estatisticamente significante para o fator tempo de espera utilizados para execução das restaurações adesivas pós clareamento. O teste de Tukey comprovou que as médias proporcionais dos tempos de aplicação do sistema adesivo pós-clareamento, quando comparados entre si , mostram que os melhores resultados foram obtidos quando o tempo de espera para aplicação do sistema adesivo foi a partir do 7o dia, sendo que o tempo de espera imediato (T1) apresentou as menores médias proporcionais e os tempos T3 e T4 (14 e 30º dias), apresentaram as... . / This work has had the aim to analyse the influence of waiting time on the adaptation and penetration capacity of resinous materials on the dental enamel submithed the bleaching treatment, through the two different bleaching agents, on thus: Carbamide Peroxide 16% (Clarigel Gold - Dentsply) and Hidrogen Peroxide 38% (Opalescense X-tra Boost - Ultradent). So, forty - eight sound bicuspids were divided in two groups according to the bleaching agent to be used, and each subdivided group in 4 (four) with 6 (six) specimens, according to the waiting time to be application of the resinous material, after the end of the bleaching treatment: immediate filling; 7 days; 14 days and 30 days. After the conclusion of the bleaching treatment the analysis of the of the composite resin adaptation was observed through the optical microscopy, under polarized light, in augment of 200x, being that, the penetration assessment of resinous prolongament in the dental enamel in augment of 400x. The results obtained were submitted to the statistical analysis, being that, the original data were transformed in proportional means of lengh of the Control Group tags and the Experimental Groups transformed in archsene. So, the Variance Analyses was made that indicated a statiscally significant difference for the waiting time factor used to perform the adhesive fillings, after bleaching. The Tukey test corroborated that the proportional means of application times of postbleaching adhesive system, when compared among them, show that the best results obtained, when the waiting time to the adhesive system application was since the 7º day, being that the immediate waiting time (T1) presented the minor proportional means and the times T3 e T4 (14 and 30º days), presented the greater proportional means, equalized among them. Besides this results, the optical microscopy... (Complete abstract, click electronic address below).
33

Análise da penetração de material resinoso ao esmalte dental em função de agente clareador e tempo /

Machado, Jeferson da Silva. January 2004 (has links)
Orientador: Maria Salete Machado Cândido / Banca: José Roberto Cury Saad / Banca: Dirceu Vieira / Resumo: Este trabalho teve por finalidade analisar a influência do tempo de espera sobre a adaptação e capacidade de penetração de materiais resinosos sobre o esmalte dental submetido ao tratamento clareador através de dois diferentes agentes clareadores, ou sejam: Peróxido de Carbamida 16% (Clarigel Gold - Dentsply) e Peróxido de Hidrogênio 38%(Opalescence X-tra Boost - Ultradent) .Assim, quarenta e oito pré-molares hígidos foram divididos em dois grupos de acordo com o agente clareador a ser utilizado, sendo, cada grupo subdividido em 4 sub-grupos com 6 espécimes de acordo com o tempo de espera para aplicação do material resinoso após o término do tratamento clareador : restauração imediata; 7dias; 14 dias e 30 dias. Após a conclusão do tratamento clareador a análise da adaptação da resina composta foi observada através de microscopia óptica comum sob luz polarizada, em aumento de 200x sendo que, a avaliação da penetração dos prolongamentos resinosos em esmalte dental em aumento de 400x. Os resultados obtidos foram submetidos à análise estatística, sendo que, os dados originais foram transformados em médias proporcionais dos comprimentos dos "tags" do Grupo Controle e dos Grupos experimentais transformados em arcoseno. Assim, foi realizada Análise de Variância que indicou uma diferença estatisticamente significante para o fator tempo de espera utilizados para execução das restaurações adesivas pós clareamento. O teste de Tukey comprovou que as médias proporcionais dos tempos de aplicação do sistema adesivo pós-clareamento, quando comparados entre si , mostram que os melhores resultados foram obtidos quando o tempo de espera para aplicação do sistema adesivo foi a partir do 7o dia, sendo que o tempo de espera imediato (T1) apresentou as menores médias proporcionais e os tempos T3 e T4 (14 e 30º dias), apresentaram as... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: This work has had the aim to analyse the influence of waiting time on the adaptation and penetration capacity of resinous materials on the dental enamel submithed the bleaching treatment, through the two different bleaching agents, on thus: Carbamide Peroxide 16% (Clarigel Gold - Dentsply) and Hidrogen Peroxide 38% (Opalescense X-tra Boost - Ultradent). So, forty - eight sound bicuspids were divided in two groups according to the bleaching agent to be used, and each subdivided group in 4 (four) with 6 (six) specimens, according to the waiting time to be application of the resinous material, after the end of the bleaching treatment: immediate filling; 7 days; 14 days and 30 days. After the conclusion of the bleaching treatment the analysis of the of the composite resin adaptation was observed through the optical microscopy, under polarized light, in augment of 200x, being that, the penetration assessment of resinous prolongament in the dental enamel in augment of 400x. The results obtained were submitted to the statistical analysis, being that, the original data were transformed in proportional means of lengh of the Control Group tags and the Experimental Groups transformed in archsene. So, the Variance Analyses was made that indicated a statiscally significant difference for the waiting time factor used to perform the adhesive fillings, after bleaching. The Tukey test corroborated that the proportional means of application times of postbleaching adhesive system, when compared among them, show that the best results obtained, when the waiting time to the adhesive system application was since the 7º day, being that the immediate waiting time (T1) presented the minor proportional means and the times T3 e T4 (14 and 30º days), presented the greater proportional means, equalized among them. Besides this results, the optical microscopy... (Complete abstract, click electronic address below). / Mestre
34

Tags: as palavras-chave do hipertexto

Pacheco Guimarães, Cleber 31 January 2010 (has links)
Made available in DSpace on 2014-06-12T18:34:27Z (GMT). No. of bitstreams: 2 arquivo457_1.pdf: 3362853 bytes, checksum: 2b467a3e82c37fdfc42e53f61df6797d (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Universidade Federal de Pernambuco / Tags são palavras-chave utilizadas para sinoptizar e caracterizar textos, imagens, sons e outros tipos de arquivos digitais. Muitos blogs (uma das tecnologias mais utilizadas na Internet) fazem uso da ferramenta tag para organizar e etiquetar seus textos. Entretanto, outras finalidades são dadas a estas palavras-chave, como a captação de visitas, o acréscimo de leitores. Este trabalho se propõe a investigar, à luz da Linguística Cognitiva, Semântica, Linguística de Texto entre outras, como os blogueiros efetivamente usam as tags. Para tanto, lançamos olhares quantitativos e qualitativos sobre um corpus composto por 30 blogs (que nos rendeu 631 tags) e por questionários que foram enviados a blogueiros. Ao término da investigação, constatou-se que, apesar de haver uma preocupação com a captação de tráfego/visitas (fenômeno que gerou palavras-chave bastante peculiares e, por vezes, insólitas), a tendência realmente é escolher tags que reflitam o conteúdo dos textos aos quais estão ligadas. Também nos foi possível caracterizar as próprias tags, em termos de sintagmas, hipônimos, sinônimos e outros. O intuito consistiu em fornecer possibilidades de aplicação deste trabalho em salas de aula
35

INVESTIGATIONS IN CRYPTIC SPECIES: CONSIDERATIONS AND APPLICATIONS FOR ESTIMATING DETECTION, OCCUPANCY, AND ABUNDANCE OF SEMI-AQUATIC SNAKES

Oldham, Christian Robert 01 January 2016 (has links)
Snake species are notoriously difficult to study in the field due to their cryptic natural-histories and secretive behaviors. Difficulties associated with detection present challenges estimating parameters including occupancy and abundance, as well as responses to habitat degradation. Our objectives were to use Passive Integrated Transponder (PIT) telemetry to enhance detection of Queensnakes (Regina septemvittata) as compared to traditional capture-mark-recapture (CMR) survey techniques and to examine occupancy and abundance of Queensnakes and Northern Watersnakes (Nerodia sipedon) in streams of differing levels of anthropogenic impact within Central Kentucky. During 2013, we captured Queensnakes and implanted them with PIT tags. We detected significantly more tagged snakes using PIT telemetry than visual surveys. We did not observe significant differences in numbers of snakes detected using PIT telemetry at different times of day. We observed relatively high site fidelity of individuals. During 2014, we conducted point-count surveys of Northern Watersnakes and Queensnakes in streams characterized as highly degraded and lightly impaired. We estimated occupancy and conditional abundance among site types. We did not observe significant differences in occupancy or abundance between historically highly-impacted sites and less-impacted sites. We were able to determine significance of some environmental variables influencing detection of snakes.
36

Formulace inkoustů pro materiálový tisk chemických značek / Ink formulation for chemical labels printing

Martiniaková, Ivana January 2019 (has links)
This diploma theses is about the study of the effect of individual components of printing compositions intended for material printing of identificaton codes, read by X-ray fluorescence. Two printing technologies were used – screen printing and pad printing. The composition of the print compositions has been optimized in term of visual recognition, print repeatability, a dry matter content providing an X-ray fluorescence signal, as well as optimization of the material print process leading to the creation of invisible identification tags for archive documents.
37

Optimalizace tisku chemického kódu s XRF identifikací / Optimization of chemical code printing with XRF identification

Uher, Tadeáš January 2020 (has links)
The Master’s thesis deals with study printing and optimization of a chemical labels with a code readable by XRF technique. The study is focusing on the identifiability of components in chemical code through data analysis in the Origin program environment and reproducibility of the analysis. The responses of the XRF signal on real samples of historical documents were studied and possible interfering elements were identified. Based on these analyses, a recommendation was formulated for the method of evaluating the obtained data, code analysis and also for the composition of the printing formulation.
38

Crystallization of a Flavonol-Specific 3-O Glucosyltransferase and Site-Directed Mutants from Grapefruit

Birchfield, Aaron, McIntosh, Cecilia 12 April 2019 (has links)
Citrus fruits are some of the most widely consumed fruits in the world and contain significant levels of flavonoids, a category of plant secondary metabolites which control taste, color, plant defense, and overall marketability. In citrus and other plants, flavonoids are found in their glucosylated form. Glucosyltransferases (GT’s) are enzymes that add glucose to secondary metabolites like flavonoids. They make up a diverse class of enzymes ubiquitous throughout the plant and animal kingdoms. While many GT’s have been identified, they vary greatly in their structural identity, and their chemical properties make it such that only a small percentage of existing GT’s have been functionally characterized. Research on GT structure function relationships strengthens the reliability of genomic databases and makes significant contributions to the field of enzyme biotechnology. Bioenergy research and custom enzyme synthesis rely on GT structural data, making this research critical to the success of many promising current and future projects. A GT was isolated from grapefruit and was shown to glucosylate the flavonol class of flavonoids at the 3-OH position, called CP3GT. Subsequent analysis showed there are specific arrangements of amino-acids inside the catalytic cleft of CP3GT that likely account for its specificity with flavonols. These interactions are not fully understood and make CP3GT an excellent model for elucidating unique structure function relationships of a GT enzyme. X-ray crystallography is one of the best methods for structure determination that allows a 3D image of the protein in question to be resolved at the molecular level. This method has vast potential for advancing plant enzymology, yet to date only 6 plant glucosyltransferases have had their crystal structures solved. The structural similarities and complementary specificities that CP3GT shares with these crystallized GT’s make CP3GT an excellent candidate for crystallization. This research hypothesizes that there are unique structural features that give CP3GT its specificity, and that these features can be elucidated using x-ray crystallography. Wild type CP3GT and 3 recently characterized mutants are being prepared for crystallization. The crystallization of 3 CP3GT mutants in addition to wild type will compliment structure/function analysis by providing insight into how structural modifications can alter enzyme function. It is recommended that protein be in its native form for crystallization, thus a thrombin-cleavage site was inserted into WT CP3GT and 3 mutants to remove tags following purification. Some studies have suggested that the presence of tags alters enzyme activity, thus this presented the opportunity to test the effect of tags by assaying both native and tagged enzyme. Initial results showed that WT CP3GT treated with thrombin retained 70 percent activity after a 2-hour treatment at 4o C. Additional assays will be conducted to fully determine tag effects and will run concurrently with crystallization experiments
39

Computational Mining and Survey of Simple Sequence Repeats (SSRs) in Expressed Sequence Tags (ESTs) of Dicotyledonous Plants

Kumpatla, Siva Prasad 07 1900 (has links)
Submitted to the faculty of the School of Informatics in partial fulfillment of the requirements for the degree Master of Science in Bioinformatics in the School of Informatics,Indiana University July, 2004 / DNA markers have revolutionized the field of genetics by increasing the pace of genetic analysis. Simple sequence repeats (SSRs) are repetitions of nucleotide motifs of 1 to 5 bases and are currently the markers of choice in many plant and animal genomes due to their abundant distribution in the genomes, hypervariable nature and suitability for high-throughput analysis. While SSRs, once developed, are extremely valuable, their development is time consuming, laborious and expensive. Sequences from many genomes are continuously made freely available in the public databases and mining of these sources using computational approaches permits rapid and economical marker development. Expressed sequence tags (ESTs) are ideal candidates for mining SSRs not only because of their availability in large numbers but also due to the fact that they represent expressed genes. Large scale SSR mining efforts in plants to date focused on monocotyledonous plants. In this project, an efficient SSR identification tool was developed and used to mine SSRs from more than 53 dicotyledonous species. A total of 92,648 non-redundant ESTs or 6.0% of the 1.54 million dicotyledonous ESTs investigated in this study were found to contain SSRs. The frequency of non-redundant-ESTs containing SSRs among the species investigated ranged from 2.65% to 16.82%. More than 80% of the non-redundant ESTs having SSRs contained a single SSR repeat while others contained 2 or more SSRs. An extensive analysis of the occurrence and frequencies of various SSR types revealed that the A/T mononucleotide, AG/GA/CT/TC dinucleotide, AAG/AGA/GAA/CTT/TTC/TCT trinucleotide and TTTA and TTAA tetranucleotide repeats are the most abundant in dicotyledonous species. In addition, an analysis of the number of repeats across species revealed that majority of the mononucleotide SSRs contained 15-25 repeats while majority of the di- and tri-nucleotide SSRs contained 5-10 repeats. By providing valuable information on the abundance of SSRs in ESTs of a large number of dicotyledonous species, this study demonstrates the potential of computational mining approach for rapid discovery of SSRs towards the development of markers for genetic analysis and related applications.
40

The Long-Tails in Content Services: How the Structure of Hybrid Networks Shape Content Popularity and Related Decision-Making

Srinivasan, Nikhil S. 12 March 2013 (has links)
No description available.

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