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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

Desenvolvimento de metodologia radiográfica e volumétrica dos diferentes estágios de desenvolvimento dentário para qualificação de material biológico em Engenharia Tecidual / Development of radiographic and volumetric metodologies from diferentes tooth development stages as a qualification for harvesting biological material for Tissue Engeneering

Duailibi Neto, Eduardo Felippe 12 March 2013 (has links)
A utilização de Células-tronco e técnicas da Engenharia Tecidual representa um grande avanço tecnológico e beneficiará muitos pacientes com suas conquistas. A descoberta de germes dentários como uma fonte confiável de células-tronco possibilitou diversas pesquisas nesta área. Duailibi et al. (2011) sugeriram uma nova classificação de desenvolvimento dentário baseada pela quantidade de material biológico coletado indicando a necessidade de métodos de diagnóstico por imagem para esta nova classificação. Na literatura diversos trabalhos indicam métodos de classificação dentária e métodos para estimar a idade fisiológica de indivíduos. O presente estudo tem o objetivo de adaptar alguns destes métodos para estimar o estágio de desenvolvimento proposto por Duailibi et al. (2011) consequentemente indicando a quantidade de células-tronco esperadas nas amostras. Para tanto, submeteu-se uma coleção de 67 dentes previamente classificados por Duailibi et al. (2011) à técnica rpcl e à tcfc para a obtenção de imagens e a aplicação de técnicas de estimativas por proporções lineares e volumétricas. Os resultados por análises lineares indicaram valores de R2 para o método de proporção de comprimento CDCP de 0,14050; CCCP de 0,65369; CCCR de 0,5408; CDCR de 0,54074; o método de proporção de área APAD de 0,23925; e método de proporção de volume VPVD de 0,08553, com valor de p menor ou igual à 0,05. Concluindo este estudo indica-se o método de rpcl utilizando a análise do comprimento entre coroa e polpa como o mais indicado para estimar o estágio de desenvolvimento. / The usage of human dental stem cells and tissue engineering technics represents a huge tecnological development and it may benefits many patients in a promissing future. The discovery of suitable source of human dental stem cells were made using tooth buds. Duailibi et al. 2011 indicated a new tooth classification on a stem cell harvesting based research, sugesting new methods for diagnosis these stages. Several method were developed for dental age assesement. The presente study aims to evaluate some of these dental age technics and make adaptations for estimating Duailibi et al. 2011 tooth stages. A 67 tooth sample previoulsy classificated by Duailbi et al. 2011 were submited through periapical parallel long cone X-rays and CBCT analysis. Age estimation ratio methods were applied by measuring tooth/root lenth, crown/root lenth, tooth/pulp lenth, crown/pulp lenth, tooth/poulp área and tooth/pulp volume. Results indicated by linear regression analisys a R2 value of tooth/pulp lenth 0,14050; crown/pulp lenth 0,65369; crown/root lenth 0,5408; tooth/root lenth 0,54074; pulp/tooth volume 0,23925; e tooth/pulp volume de 0,08553, with p value of 0,005. In conclusion , the best method for estimating Duailibi et al. 2011 tooth classification techinic is made by using periapical long cone X-rays using crown/pulp lenth ratio.
102

Desenvolvimento de metodologia radiográfica e volumétrica dos diferentes estágios de desenvolvimento dentário para qualificação de material biológico em Engenharia Tecidual / Development of radiographic and volumetric metodologies from diferentes tooth development stages as a qualification for harvesting biological material for Tissue Engeneering

Eduardo Felippe Duailibi Neto 12 March 2013 (has links)
A utilização de Células-tronco e técnicas da Engenharia Tecidual representa um grande avanço tecnológico e beneficiará muitos pacientes com suas conquistas. A descoberta de germes dentários como uma fonte confiável de células-tronco possibilitou diversas pesquisas nesta área. Duailibi et al. (2011) sugeriram uma nova classificação de desenvolvimento dentário baseada pela quantidade de material biológico coletado indicando a necessidade de métodos de diagnóstico por imagem para esta nova classificação. Na literatura diversos trabalhos indicam métodos de classificação dentária e métodos para estimar a idade fisiológica de indivíduos. O presente estudo tem o objetivo de adaptar alguns destes métodos para estimar o estágio de desenvolvimento proposto por Duailibi et al. (2011) consequentemente indicando a quantidade de células-tronco esperadas nas amostras. Para tanto, submeteu-se uma coleção de 67 dentes previamente classificados por Duailibi et al. (2011) à técnica rpcl e à tcfc para a obtenção de imagens e a aplicação de técnicas de estimativas por proporções lineares e volumétricas. Os resultados por análises lineares indicaram valores de R2 para o método de proporção de comprimento CDCP de 0,14050; CCCP de 0,65369; CCCR de 0,5408; CDCR de 0,54074; o método de proporção de área APAD de 0,23925; e método de proporção de volume VPVD de 0,08553, com valor de p menor ou igual à 0,05. Concluindo este estudo indica-se o método de rpcl utilizando a análise do comprimento entre coroa e polpa como o mais indicado para estimar o estágio de desenvolvimento. / The usage of human dental stem cells and tissue engineering technics represents a huge tecnological development and it may benefits many patients in a promissing future. The discovery of suitable source of human dental stem cells were made using tooth buds. Duailibi et al. 2011 indicated a new tooth classification on a stem cell harvesting based research, sugesting new methods for diagnosis these stages. Several method were developed for dental age assesement. The presente study aims to evaluate some of these dental age technics and make adaptations for estimating Duailibi et al. 2011 tooth stages. A 67 tooth sample previoulsy classificated by Duailbi et al. 2011 were submited through periapical parallel long cone X-rays and CBCT analysis. Age estimation ratio methods were applied by measuring tooth/root lenth, crown/root lenth, tooth/pulp lenth, crown/pulp lenth, tooth/poulp área and tooth/pulp volume. Results indicated by linear regression analisys a R2 value of tooth/pulp lenth 0,14050; crown/pulp lenth 0,65369; crown/root lenth 0,5408; tooth/root lenth 0,54074; pulp/tooth volume 0,23925; e tooth/pulp volume de 0,08553, with p value of 0,005. In conclusion , the best method for estimating Duailibi et al. 2011 tooth classification techinic is made by using periapical long cone X-rays using crown/pulp lenth ratio.
103

Idades isocronicas Pb/Pb e geoquimica isotopica de Pb das rochas carbonaticas do grupo Bambui na porcao sul da bacia do Sao Francisco

BABINSKI, MARLY 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:37:32Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:17Z (GMT). No. of bitstreams: 1 05174.pdf: 4868507 bytes, checksum: ef4d7e8312562d1a1e608bf1fd65e9ec (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo
104

Idades isocronicas Pb/Pb e geoquimica isotopica de Pb das rochas carbonaticas do grupo Bambui na porcao sul da bacia do Sao Francisco

BABINSKI, MARLY 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:37:32Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:17Z (GMT). No. of bitstreams: 1 05174.pdf: 4868507 bytes, checksum: ef4d7e8312562d1a1e608bf1fd65e9ec (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo
105

Estudo dos radionuclídeos naturais - Ra-226, Ra-228 e Pb-210 - em alguns registros sedimentares do Atlântico Sudoeste ao longo do Holoceno / Study of natural radionuclides - 226Ra, 228Ra and 210Pb - in marine sediment cores from Southwest Atlantic during the Holocene

COSTA, ALICE M.R. 21 December 2016 (has links)
Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-12-21T11:51:34Z No. of bitstreams: 0 / Made available in DSpace on 2016-12-21T11:51:34Z (GMT). No. of bitstreams: 0 / Os radionuclídeos naturais das séries radioativas do 238U e do 232Th têm sido aplicados com sucesso como traçadores de processos ambientais atuais e mudanças climáticas. O 210Pb (meia-vida de 22,2 anos) é empregado na técnica de datação geocronológica de testemunhos sedimentares dos últimos 100-150 anos e na determinação de taxa de sedimentação. As concentrações dos isótopos 226Ra e 228Ra (meia-vida de 1.600 anos e 5,75 anos, respectivamente) auxiliam no cálculo das atividades de 210Pb em excesso no sedimento e auxiliam na identificação de processos marinhos importantes, como, por exemplo, a intrusão de água subterrânea. Neste trabalho foram quantificadas as concentrações de atividade de 226Ra, 228Ra e 210Pb em quatro testemunhos marinhos curtos coletados desde a plataforma continental até o talude superior do Atlântico Sudoeste. A partir dos resultados obtidos, as taxas de sedimentação em cada local e as idades de cada fatia de sedimento foram determinadas pelo método de datação geocronológica com 210Pb. As amostras sedimentares sofreram digestão total ácida em microondas. A separação radioquímica sequencial de 226Ra, 228Ra e 210Pb foi realizada com a obtenção dos precipitados de Ba(Ra)SO4 e PbCrO4. As medidas α total do 226Ra e β total do 228Ra e do 210Pb a partir dos precipitados foram feitas em um detector proporcional de fluxo gasoso de baixa radiação de fundo. Com relação aos testemunhos analisados, as concentrações de atividade dos radionuclídeos variaram de 14 Bq.kg-1 a 154 Bq.kg-1 para o 226Ra; de 17 Bq.kg-1 a 45 Bq.kg-1 para o 228Ra; de 20 Bq.kg-1 a 2.073 Bq.kg-1 para o 210Pb. Valores altos de 210Pb foram encontrados no topo de todos os perfis sedimentares, proveniente principalmente da deposição atmosférica. Os dados coletados neste trabalho estão na mesma faixa de grandeza de outros relacionados a medições de 226Ra, 228Ra, 210Pb em áreas não contaminadas do Oceano Atlântico Sudoeste. As taxas de sedimentação diminuíram com o aumento da profundidade de coluna dágua, cujos valores variaram de 0,049 cm.ano-1 a 0,40 cm.ano-1. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
106

基於近紅外線影像之年齡層估算機制 / A mechanism for age classification using near-infrared images

林言翰, Lin, Yan-Han Unknown Date (has links)
近紅外線影像由於其物理特性與成像方式,其紋理細節都有發散模糊不清的現象,對於以紋理為主要特徵的年齡辨識問題而言更具挑戰。本論文主要目的是以近紅外線人臉影像為基礎,找出對近紅外線年齡特徵有最佳描述力的特徵描述子,辨識近紅外線影像中被拍攝者的年齡區間,建構整個年齡層估算機制。 相關研究一部分關注可見光年齡辨識,另一部分則聚焦在近紅外線人臉辨識,目前還沒有近紅外線年齡辨識的相關文獻能參考,如何從接近的研究領域找尋是適當的演算法是本研究遇到的第一個挑戰。在資料庫的部分,FGNET和MORPH常被用於可見光的年齡辨識議題; PolyU和LDHF則用於近紅外線人臉辨識相關研究,在目前沒有近紅外線年齡資料庫的情況,本研究自建RSNIR(Intel RealSense Near-Infrared Age Database),因此如何標準化拍攝環境流程、蒐集穩定的近紅外線影像是本研究面臨的第二個挑戰。 區域性特徵擷取方法的關鍵在於特徵描述子的描述力。本研究以LBP(Local Binary Patterns)為基礎,探討LBP在內的24個特徵描述子,最後實驗測試各個描述子在RSNIR的辨識率,結果發現基本型Fuzzy LBP和擴充型RILBP對近紅外線年齡特徵有最佳描述力。在空間譜子區塊(patch)設計部分,以3x3切割子區塊數的辨識效果最好,反應出其與影像校正時的人臉影像空間定義方式有關。
107

Détermination de l'âge et du sexe et modélisation de la canine en anthropologie médico-légale

Tardivo, Delphine 09 November 2011 (has links)
Les méthodes osseuses de diagnose sexuelle donnent d’excellents résultats, avec des taux de bonnes prédictions du sexe supérieurs à 90%. Néanmoins, les éléments osseux ne sont pas toujours disponibles et, lorsqu’ils le sont, selon les causes de la mort et/ou les conditions de conservation du corps, ils peuvent avoir été lourdement dégradés. Pour parvenir à déterminer le sexe d’un individu dans ces situations là, des techniques dentaires de diagnose sexuelle sont nécessaires.Contrairement à la détermination du sexe, la problématique de la détermination de l’âge a fait l’objet de nombreuses études et d’autant de propositions de techniques différentes, signe d’une insuffisance de l’ensemble de ces méthodes, que la littérature n’a pas manqué de mettre en exergue.Le premier objectif de ce travail est de proposer une technique dentaire de détermination du sexe simple et précise, de façon à pouvoir répondre à cette problématique anthropologique de façon fiable en l’absence d’autres éléments du squelette.Le second est de développer une méthode d’estimation de l’âge de mise en œuvre facile, rapide et ne nécessitant ni un plateau technique lourd, ni la détérioration du matériel, pour une application aussi bien anthropologique que médico-légale. L’échantillon d’apprentissage était composé de 210 scanners d’individus présentant chacun 4 canines saines. L’échantillon d’application était composé de 55 scanners d’individus, présentant chacun au moins 1 canine saine. Les volumes pulpaire et total de chaque dent ont été modélisés et calculés à l’aide du logiciel Mimics. Une régression logistique binaire a été utilisée pour déterminer sept modèles de prédiction du sexe, en fonction du nombre et du type de canines exploitables. La comparaison des aires sous la courbe ROC a mis en évidence une plus grande performance du modèle utilisant les volumes des 4 canines. La méthode des moindres carrés pondérés a été utilisée pour déterminer les équations d’estimation de l’âge pour les sept mêmes modèles. Une plus grande performance du modèle utilisant les volumes des 2 canines maxillaires a été mise en évidence. Toutes ces régressions ont été testées sur l’échantillon d’application pour procéder à leur validation externe.Il s’avère que dans un contexte scientifique historique où les canines mandibulaires constituaient l’outil dentaire de référence dans la diagnose sexuelle, la modélisation tridimensionnelle souligne l’intérêt potentiel de leurs homologues maxillaires. Par ailleurs, il semblerait que l’évaluation de la réduction pulpaire physiologique, imputable à l’apposition naturelle de dentine secondaire sur les canines uniquement, soit un critère performant dans la détermination de l’âge.A défaut d’être parfaits, les modèles proposés à l’issue cette étude permettent donc toutefois de disposer d’éléments fiables, qui ont toute leur place dans l’indispensable faisceau de preuves, nécessaire à la détermination de l’âge et du sexe dans le cadre d’une identification estimative. / The bone methods of sexual diagnosis give excellent results, with rates of good predictions over 90%. Nonetheless, bones are not always available and, when they are, according to the causes of death and/or storage conditions of the body, they may have been severely degraded. To be able to determine the sex of an individual in these situations, dental techniques of sexual diagnosis are needed.In contrast to sex determination, the problem of age estimation has been the topic of many studies and so many different techniques, evidence of failure of all these methods, which the literature did not fail to highlight.The first aim of this work was to propose a simple and accurate dental technique for determining sex, in order to resolve this anthropological issue, reliably in the absence of other elements of the skeleton.The second was to develop a method for estimating the age of easy and fast implémentation, neither requiring a heavy technical support nor damage to material, for an application as well in forensics as in anthropology.The training sample consisted of 210 subjects’ CT-scans, each with four canines healthy. The validation sample was composed of 55 CT-scans, each with at least one healthy canine. Pulp and total volumes of each tooth were modeled and calculated using the software Mimics . A binary logistic regression was used to determine seven prediction models of sex, according to the number and type of canine available in practice. The comparison of the areas under the ROC curve showed a greater performance of the model using the volumes of the four canines. The weighted least squares method was used to determine the equations for estimating the age for the same seven models. Greater performance of the model using the volumes of maxillary canines has been demonstrated. All these regressions were tested on the validation sample to perform their external validation.It turns out that in a scientific context where historical mandibular canines were the reference tool in the sex diagnosis, three-dimensional modeling emphasizes the potential value of maxillary counterparts. Moreover, it appears that the evaluation of the physiological pulp reduction, due to the natural apposition of secondary dentine on canines only, is a performance criterion in determining age.The models proposed in this study can therefore have reliable evidence, which all have all their place in the necessary body of evidence for determining age and sex, in estimating identification.
108

Detekce osob a hodnocení jejich pohlaví a věku v obrazových datech / Detection of persons and evaluation of gender and age in image data

Dobiš, Lukáš January 2020 (has links)
Táto diplomová práca sa venuje automatickému rozpoznávaniu ludí v obrazových dátach s využitím konvolučných neurónových sieti na určenie polohy tváre a následnej analýze získaných dát. Výsledkom analýzy tváre je určenie pohlavia, emócie a veku osoby. Práca obsahuje popis použitých architektúr konvolučných sietí pre každú podúlohu. Sieť na odhad veku má natrénované nové váhy, ktoré sú vzápätí zmrazené a majú do svojej architektúry vložené LSTM vrstvy. Tieto vrstvy sú samostatne dotrénované a testované na novom datasete vytvorenom pre tento účel. Výsledky testov ukazujú zlepšenie predikcie veku. Riešenie pre rýchlu, robustnú a modulárnu detekciu tváre a ďalších ludských rysov z jedného obrazu alebo videa je prezentované ako kombinácia prepojených konvolučných sietí. Tieto sú implementované v podobe skriptu a následne vysvetlené. Ich rýchlosť je dostatočná pre ďalšie dodatočné analýzy tváre na živých obrazových dátach.
109

Identification of water origin and water-rock interaction in a complex multi-aquifer system in the Dead Sea Rift by applying chemistry and isotopes

Wilske, Cornelia Maria 14 January 2020 (has links)
Die vorliegende Studie befasst sich mit einer hydrochemischen Untersuchung des Aquifersystems auf der Westseite des Toten Meeres. Für die Untersuchungen der Grundwasserressourcen der kreidezeitlichen Grundwasserleiter, insbesondere Grundwasserherkunft, Mischprozesse, Identifizierung von Wasser-Gesteins- Wechselwirkungen, Datierung von Grundwasseraltersbereichen, Identifizierung der Herkunft des Quellen an der Küste des Toten Meeres und Abtrennung quartärer Grundwassermuster, wurde eine Tracerkombination auf Wasser- und Gesteinsproben angewendet. Die hier vorgestellte Multitracer-Methodik ist auch in anderen datenarmen Gebieten mit komplexer Hydrogeologie (Karst oder Störungen) unter anthropogenem Einfluss anwendbar. / The present study deals with a hydrochemical investigation of the aquifer system on the western side of the Dead Sea. To examine the groundwater resources of the Cretaceous aquifer, particularly groundwater origins, mixing processes, identification of water-rock interaction, dating of groundwater age ranges in the aquifers and identification of spring water origins at the Dead Sea coast and separation of Quaternary groundwater patterns, a combination of tracer is applied on water and rock samples. The multi-tracer method presented here is also applicable in other data-poor areas with complex hydrogeology (karst or fracture) under anthropogenic influence.
110

Apprentissage profond pour la description sémantique des traits visuels humains / Deep learning for semantic description of visual human traits

Antipov, Grigory 15 December 2017 (has links)
Les progrès récents des réseaux de neurones artificiels (plus connus sous le nom d'apprentissage profond) ont permis d'améliorer l’état de l’art dans plusieurs domaines de la vision par ordinateur. Dans cette thèse, nous étudions des techniques d'apprentissage profond dans le cadre de l’analyse du genre et de l’âge à partir du visage humain. En particulier, deux problèmes complémentaires sont considérés : (1) la prédiction du genre et de l’âge, et (2) la synthèse et l’édition du genre et de l’âge.D’abord, nous effectuons une étude détaillée qui permet d’établir une liste de principes pour la conception et l’apprentissage des réseaux de neurones convolutifs (CNNs) pour la classification du genre et l’estimation de l’âge. Ainsi, nous obtenons les CNNs les plus performants de l’état de l’art. De plus, ces modèles nous ont permis de remporter une compétition internationale sur l’estimation de l’âge apparent. Nos meilleurs CNNs obtiennent une précision moyenne de 98.7% pour la classification du genre et une erreur moyenne de 4.26 ans pour l’estimation de l’âge sur un corpus interne particulièrement difficile.Ensuite, afin d’adresser le problème de la synthèse et de l’édition d’images de visages, nous concevons un modèle nommé GA-cGAN : le premier réseau de neurones génératif adversaire (GAN) qui produit des visages synthétiques réalistes avec le genre et l’âge souhaités. Enfin, nous proposons une nouvelle méthode permettant d’employer GA-cGAN pour le changement du genre et de l’âge tout en préservant l’identité dans les images synthétiques. Cette méthode permet d'améliorer la précision d’un logiciel sur étagère de vérification faciale en présence d’écarts d’âges importants. / The recent progress in artificial neural networks (rebranded as deep learning) has significantly boosted the state-of-the-art in numerous domains of computer vision. In this PhD study, we explore how deep learning techniques can help in the analysis of gender and age from a human face. In particular, two complementary problem settings are considered: (1) gender/age prediction from given face images, and (2) synthesis and editing of human faces with the required gender/age attributes.Firstly, we conduct a comprehensive study which results in an empirical formulation of a set of principles for optimal design and training of gender recognition and age estimation Convolutional Neural Networks (CNNs). As a result, we obtain the state-of-the-art CNNs for gender/age prediction according to the three most popular benchmarks, and win an international competition on apparent age estimation. On a very challenging internal dataset, our best models reach 98.7% of gender classification accuracy and an average age estimation error of 4.26 years.In order to address the problem of synthesis and editing of human faces, we design and train GA-cGAN, the first Generative Adversarial Network (GAN) which can generate synthetic faces of high visual fidelity within required gender and age categories. Moreover, we propose a novel method which allows employing GA-cGAN for gender swapping and aging/rejuvenation without losing the original identity in synthetic faces. Finally, in order to show the practical interest of the designed face editing method, we apply it to improve the accuracy of an off-the-shelf face verification software in a cross-age evaluation scenario.

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