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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.
221

Buildings and Hecke Algebras

Parkinson, James William January 2005 (has links)
We establish a strong connection between buildings and Hecke algebras through the study of two algebras of averaging operators on buildings. To each locally finite regular building we associate a natural algebra B of chamber set averaging operators, and when the building is affine we also define an algebra A of vertex set averaging operators. In the affine case, it is shown how the building gives rise to a combinatorial and geometric description of the Macdonald spherical functions, and of the centers of affine Hecke algebras. The algebra homomorphisms from A into the complex numbers are studied, and some associated spherical harmonic analysis is conducted. This generalises known results concerning spherical functions on groups of p-adic type. As an application of this spherical harmonic analysis we prove a local limit theorem for radial random walks on affine buildings.
222

An investigation into the relationship between static and dynamic gait features : a biometrics perspective

Alawar, Hamad Mansoor Mohd Aqil January 2014 (has links)
Biometrics is a unique physical or behavioral characteristic of a person. This unique attribute, such as fingerprints or gait, can be used for identification or verification purposes. Gait is an emerging biometrics with great potential. Gait recognition is based on recognizing a person by the manner in which they walk. Its potential lays in that it can be captured at a distance and does not require the cooperation of the subject. This advantage makes it a very attractive tool for forensic cases and applications, where it can assist in identifying a suspect when other evidence such as DNA, fingerprints, or a face were not attainable. Gait can be used for recognition in a direct manner when the two samples are shot from similar camera resolution, position, and conditions. Yet in some cases, the only sample available is of an incomplete gait cycle, low resolution, low frame rate, a partially visible subject, or a single static image. Most of these conditions have one thing in common: static measurements. A gait signature is usually formed from a number of dynamic and static features. Static features are physical measurements of height, length, or build; while dynamic features are representations of joint rotations or trajectories. The aim of this thesis is to study the potential of predicting dynamic features from static features. In this thesis, we have created a database that utilizes a 3D laser scanner for capturing accurate shape and volumes of a person, and a motion capture system to accurately record motion data. The first analysis focused on analyzing the correlation between twenty-one 2D static features and eight dynamic features. Eleven pairs of features were regarded as significant with the criterion of a P-value less than 0.05. Other features also showed a strong correlation that indicated the potential of their predictive power. The second analysis focused on 3D static and dynamic features. Through the correlation analysis, 1196 pairs of features were found to be significantly correlated. Based on these results, a linear regression analysis was used to predict a dynamic gait signature. The predictors chosen were based on two adaptive methods that were developed in this thesis: "the top-x" method and the "mixed method". The predictions were assessed for both for their accuracy and their classification potential that would be used for gait recognition. The top results produced a 59.21% mean matching percentile. This result will act as baseline for future research in predicting a dynamic gait signature from static features. The results of this thesis bare potential for applications in biomechanics, biometrics, forensics, and 3D animation.
223

Avaliação da capacidade funcional de pacientes submetidos ao transplante hepático no Hospital de Clínicas de Porto Alegre

Cabeleira, Daiane Dias January 2016 (has links)
Introdução: Doentes Hepáticos mesmo após o Transplante de Fígado (TF) apresentam heranças fisiopatológicas que podem influenciar na diminuição da Capacidade Funcional (CF). Objetivo: Traçar o perfil dos pacientes pós TF em relação à CF, e definir quais os melhores exercícios físicos para compor futuro programa de condicionamento físico dos pacientes, tanto antes como depois do TF. Métodos: Estudo transversal com 52 pacientes submetidos ao TF entre os anos de 2002 e 2013. Foi realizado o Teste de Caminhada de 6 minutos (TC6). Resultados: 51,9% dos pacientes eram homens, sendo a média de idade da amostra 58 + 10,26 anos. Entre os participantes, 48,1% eram hipertensos, 42,3% obesos e 40,4% tinham diabetes tipo II. Tacrolimus é o medicamento mais utilizado em 84,6% dos pacientes. O DPTC6 média total foi de 497 + 90 metros, onde os homens andavam distância média mais alta que as mulheres (531 + 70 e 460 + 95 metros respectivamente). Sexo e Idade foram significativas (p=0,002 e p=0,011), evidenciando que a média do TC6 é maior em homens mais jovens do que em mulheres, independentemente do tempo transcorrido após o TF (p>0,05). Em relação a prática de exercícios físicos, apesar de não ser estatisticamente significativa, evidenciou-se que praticantes possuem melhores DPTC6. Conclusão: A DPTC6 por pacientes já submetidos ao Transplante de Fígado no Hospital de Clínicas de Porto Alegre, é indicativa de boa capacidade funcional, principalmente entre os pacientes mais jovens, os do sexo masculino e praticantes de exercícios físicos. / Introduction: The pathophysiological profile of patients with liver disease may impact functional capacity even after liver transplantation (LT). Objective: To describe functional capacity after LT in a group of Brazilian patients. Methods: This cross-sectional study included 52 patients submitted to LT between 2002 and 2013. Functional capacity was determined using the six-minute walk test (6MWT). Results: The mean age of the overall sample was 58 ± 10.26 years, and 51.9% were male. Hypertension was detected in 48.1%, obesity in 42.3%, and type 2 diabetes in 40.4%. Tacrolimus was the most used medicine (84.6% of patients). The mean distance traveled in the 6MWT was 497 + 90 m (531 ± 70 m for males vs. 460 ± 95 m for females). Gender and age were significantly associated with 6MWT results (p=0.002 and p=0.011), showing a higher mean 6MWT distance in younger men than in women, regardless of the time elapsed since LT (p<0.05). In relation to physical exercise, physically active individuals had more favorable 6MWT results; however, this association was not statistically significant. Conclusion: The present group of LT patients had good functional capacity as measured by the 6MWT, especially younger patients, male patients, and physically active patients.
224

Estudo do comportamento da saturação periférica de oxigênio durante o teste de caminhada de 6 minutos em pacientes com doenças pulmonares crônicas

Dumke, Anelise January 2006 (has links)
Objetivo: Estudar o efeito da monitorização contínua da oximetria de pulso (SpO2) durante o teste de caminhada de 6 minutos (TC6m), na detecção da hipoxemia induzida pelo exercício, em pacientes com sintomas respiratórios. Métodos: Os pacientes realizaram testes de função pulmonar e TC6m. A saturação e a freqüência cardíaca foram determinadas por um oxímetro de pulso e os dados transferidos simultaneamente para um computador através de telemetria. Comparamos a menor saturação atingida durante o teste com os valores da SpO2 obtidos imediatamente após o TC6m. Também foram comparadas as diferenças clínico funcionais dos pacientes agrupados de acordo com a presença de dessaturação (SpO2 repouso – SpO2 no exercício 4%) e SpO2 88%. Resultados: Foram estudados 452 pacientes (236 homens, 61 ± 13 anos). A capacidade vital forçada (CVF), o volume expiratório forçado no primeiro segundo (VEF1), a relação VEF1/CVF e a capacidade de difusão pulmonar (DCO) foram respectivamente 65,8 ± 18,6% do previsto, 52,6 ± 23,7% do previsto, 62,8 ± 18,8% e 51,7 ± 20,9% do previsto. A média da SpO2 mínima registrada com auxílio de telemetria durante o TC6m foi de 89,9 ± 6,5% e da SpO2 no final do teste foi de 91,1 ± 6,5% (p<0,001). Em 241 pacientes (53,3%) ocorreu dessaturação no TC6m. Foram observados dois padrões diferenciados de dessaturação durante o exercício: um grupo de pacientes dessaturou no início do TC6m e recuperou a SpO2 antes do final do mesmo (57 pacientes, 23,7% dos pacientes que dessaturaram) e o outro grupo apresentou queda da SpO2 persistente até o final do exercício. A SpO2 basal e os valores de função pulmonar foram significativamente mais altos no grupo de pacientes com o primeiro padrão de dessaturação. A SpO2 foi 88% em 148 pacientes; em 26 destes (17,6%) níveis de SpO2 88% foram detectados somente durante o TC6m. Conclusão: Nosso estudo demonstra que a mensuração contínua da SpO2 durante o TC6m é melhor que a mensuração da SpO2 imediatamente após o teste para detectar dessaturação induzida por exercício. / Objective: To study the effect of continuous measurement of pulse oximetry (SpO2) during six-minute walk test (6MWT) on detection of exercise induced hypoxemia in patients with respiratory complaints. Methods: Patients performed lung function tests and 6MWT. SpO2 and pulse rate were obtained by a pulse oximeter and continuously transferred to a computer using telemetry. The lowest saturation reached during the test was compared with the SpO2 measured immediately after the 6MWT. We also compared functional and clinical differences of patients grouped according to desaturation (rest SpO2 - exercise SpO2 4%) and SpO2 88%. Results: We studied 452 patients (236 men, 61 ± 13 years old). Mean forced vital capacity (FCV), forced expiratory volume in 1 s (FEV1), FEV1/FCV and pulmonary diffusion capacity (DLCO) were 65.8 ± 18.6% of predicted, 52.6 ± 23.7% of predicted, 62.8 ± 18.8% and 51.7 ± 20.9% of predicted, respectively. Mean of lowest SpO2 registered using telemetry during 6MWT was 89.9% ± 6.5% and at the end of test 91.1% ± 6.5% (p<0.001). Desaturation was observed in 241 patients (53.3%). There were two different patterns of desaturation: SpO2 decrease at the beginning of the 6MWT with recovery before the test end (57 patients, 23.7% of the patients with desaturation) and SpO2 decrease maintained at the end of exercise. Rest SpO2 and lung function values were significantly higher in patients with the first desaturation pattern. SpO2 88% was observed in 148 patients; in 26 of these cases (17.6%) SpO2 88% levels were only detected during the 6MWT. Conclusion: Continuous SpO2 measuring is better than SpO2 measurement performed immediately after 6MWT in detecting exercise induced desaturation.
225

Paisagens caminhantes / Landscapes Walking

Mota, Artur Dória January 2016 (has links)
MOTA, Artur Dória. Paisagens caminhantes. 2016. 215f. – Dissertação (Mestrado) – Universidade Federal do Ceará, Programa de Pós-graduação em Artes, Fortaleza (CE), 2016. / Submitted by Gustavo Daher (gdaherufc@hotmail.com) on 2016-09-22T17:50:18Z No. of bitstreams: 1 2016_dis_admota.pdf: 9469438 bytes, checksum: ab20256412b10f9b2225c95a99cc696c (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2016-09-22T23:29:12Z (GMT) No. of bitstreams: 1 2016_dis_admota.pdf: 9469438 bytes, checksum: ab20256412b10f9b2225c95a99cc696c (MD5) / Made available in DSpace on 2016-09-22T23:29:12Z (GMT). No. of bitstreams: 1 2016_dis_admota.pdf: 9469438 bytes, checksum: ab20256412b10f9b2225c95a99cc696c (MD5) Previous issue date: 2016 / This dissertation is a propose of practice walker as metodology of creation. In several relational levels, city|street, body, home|room, are spaces on stage of mutation that adhere criatively each other, generating narrative sparks and new forms inhabit it. A walker process, on what the artist|researcher, from the walk|performance, cross the city propond interventions, apropriations and refleting about the owner process to artistic make|create. Fortaleza, the city on the question, is deph the remants that your urban dilatation made question to forgot. Small details, but substancially powerful, that sutented the city, at the same time in surviver to her, in on more, modern paradoxes. With the foot, i create with street a performative overlap of new knowledges. Walker alchemy: return to the elementar practice, which pressuposes another state with relation with the enviroment. Relation it which drives capacities of creation rise a new ways of life. The landscap, ultimely, is the intensive mark, the mode that apears to the other, this third part who comes. The walk converge in another experimental practices (colect, write, plant) and arrive on elaboration of nomads landsacpes: elemental minors body operated for your own desapearing state. / Esta dissertação é uma proposta de prática caminhante como metodologia do criar. Em vários níveis relacionais, cidade|rua, corpo, casa|quarto, são espaços em mutação que aderem criativamente entre si, gerando faíscas narrativas e novos modos de habitá-los. Um processo caminhante, em que o artista-pesquisador, a partir do caminhar|performance, percorre a cidade propondo intervenções, apropriações, refletindo sobre o próprio processo do fazer|criar artístico. Fortaleza, a cidade em questão, é aprofundada nos resquícios que sua dilatação urbana fez questão de esquecer. Detalhes menores, mas substancialmente potentes, que sustentam a cidade ao mesmo tempo em que sobrevivem a ela, em mais um, entre os tantos paradoxos modernistas. Com os pés, gero com a rua uma justaposição performática de novos saberes. Alquimia caminhante: retorno a uma prática elementar, que pressupõe outro estado de relação com o ambiente. Relação esta que impulsiona capacidades de criação que ascendam a novos modos de vida. A paisagem, por fim, é a marca intensiva deste processo, o meio pelo qual ele aparecerá ao outro, esta terceira parte que vem. A caminhada converge em outras práticas experimentais (coleta, escrita, plantio) e deságua na elaboração de paisagens nômades: corpo de elementos menores acionados por seu próprio estado de desaparecimento.
226

Abordagem de martingais para análise assintótica do passeio aleatório do elefante / Martingale approach for asymptotic analysis of elephant random walk

Milton Miranda Neto 20 August 2018 (has links)
Neste trabalho, estudamos o passeio aleatório do elefante introduzido em (SCHUTZ; TRIMPER, 2004). Um processo estocástico não Markoviano com memória de alcance ilimitada que apresenta transição de fase. Nosso objetivo é demonstrar a convergência quase certa do passeio aleatório do elefante nos casos subcrítico e crítico. Além destes resultado, também apresentamos a demonstração do Teorema Central do Limite para ambos os regimes. Para o caso supercrítico, vamos demonstrar a convergência do passeio aleatório do elefante para uma variável aleatória não normal com base nos artigos (BAUR; BERTOIN, 2016), (BERCU, 2018) e (COLETTI; GAVA; SCHUTZ, 2017b). / In this work we study the elephant random walk introduced in (SCHUTZ; TRIMPER, 2004), a discrete time, non-Markovian stochastic process with unlimited range memory that presents phase transition. Our objective is to proof the almost sure convergence for the subcritical and critical regimes of the model. We also present a demonstration of the Central Limit Theorem for both regimes. For the supercritical regime we proof the convergence of the elephant random walk to a non-normal random variable based on the articles (BAUR; BERTOIN, 2016), (BERCU, 2018) and (COLETTI; GAVA; SCHUTZ, 2017b).
227

Probabilité de survie d'un processus de branchement dans un environnement aléatoire markovien / Survival probability of a branching process in a markovian random environment

YE, Yinna 08 June 2011 (has links)
L’objet de cette thèse est d’étudier la probabilité de survie d’un processus de branchement en environnement aléatoire markovien et d’étendre dans ce cadre les résultats connus en milieu aléatoire i.i.d.. le cœur de l’étude repose sur l’utilisation des théorèmes limites locaux pour une marche aléatoire centrée (Sn)n≥0 sur R à pas markoviens et pour (rnn)n≥0, où mn = min (0, S1,... , Sn). Pour traiter le cas d’un environnement aléatoire markovien, nous développons dans un premier temps une étude des théorèmes locaux pour une chaîne semi-markovienne à valeurs réelles en améliorant certains résultats déjà connus et développés initialement par E. L. Presman (voir aussi [21]). Nous utilisons ensuite ces résultats pour l’étude du comportement asymptotique de la probabilité de survie d’un processus de branchement critique en environnement aléatoire markovien. Les résultats principaux de cette thèse (théorème limite local et son application au processus de branchement critique eu milieu aléatoire) ont été acceptés et publiés dans le Comptes Rendus de l‘Académie des Sciences ([20]). Le texte principal de cette mémoire de thèse consisite les détails des preuves. / The purpose of this thesis is to study the survival probability of a branching process in markovian random environment and expand in this framework some known results which have been developed for a branching processus in i.i.d. random environment, the core of the study is based on the use of the local limit theorem for a centered random walk (Sn)n≥o on R with markovian increasements and for (mn)n≥0. where mn = min (O. S1,……. , Sn). In order to treat the case of a markovian random environment, we establish firstly a local limit theorem for a semi-markovian chain on R. which improves certain results developed initially by E. P. Presman (see also [21]). And then we use these results to study the asymptotic behavior of a critical branching process in markovian environment. The main results et this thesis (local limit theorem and its application to the critical branching process in random environment) are accepted and published in Comptes Rendus de l’Académie des Sciences ([20]). The principal text et this thesis contains the details of the proofs.
228

Passeio aleatório quântico em um ambiente periódico

Bartlett, Thomas M. January 2013 (has links)
O passeio aleatório quântico foi totalmente entendido por [3] e desde então muitos esforços foram feitos para compreender casos mais gerais como no passeio aleatório tradicional. Nós introduzimos o caso periódico e discutimos a heurística sendo considerada como uma partícula quântica difundindo em um cristal atômico linear. Assim, estendemos o teorema de Grimmett-Janson- Scudo [3] para este caso que é um método para obter a densidade de probabilidade limite do operador posição dependendo da diagonalização da matriz de evolução unitária e mostramos que o caso periódico é de fato balístico, [9]. Como um exemplo, édiscutida a densidade probabilidade limite de período dois. / The homogeneous quantum random walk was completely understood by [3] and since then many efforts were made to compreehend more general cases like in the tradicional random walk. We introduce the periodic case and discuss a heuristic to be considered as a quantum particle diffusion in a atomic linear crystal. Thus, we extend the theorem of Grimmett-Janson-Scudo [3] to this case which is a method to obtain the limit of the probability density of the position operator depending on the diagonalization of the unitary evolution matrix and show that the periodic case is in fact ballistic, [9]. As an example, it is shown the limit probability density of the period two.
229

Avaliação do desempenho na distância percorrida no teste de caminhada de seis minutos e qualidade de vida em pacientes com bronquiectasias não-fibrocísticas

Jacques, Patrícia Santos January 2012 (has links)
Objetivos: Avaliar o desempenho no teste de caminhada de seis minutos (TC6M) em pacientes adultos com bronquiectasias não fibrocísticas, estabelecendo associações entre TC6M e qualidade de vida relacionada à saúde (QVRS). Secundariamente, determinar relações entre TC6M, achados clínicos e função pulmonar a fim de identificar preditores de tolerância ao exercíco. Métodos: Estudo transversal envolvendo pacientes com bronquiectasias não fibrocística, idade ≥ 18 anos, com pelo menos um sintoma respiratório por 2 ou mais anos e volume expiratório forçado no primeiro segundo (VEF1) ≤ 70% do previsto. Realizou-se avaliação clínica, função pulmonar, TC6M e QVRS pelo questionário Short-Form 36. Resultados: Foram incluídos 70 pacientes (48 mulheres; idade média 54,5±17,7 anos; VEF1 médio 44,9±14,5%). Desempenho alterado no TC6M foi observado em 23 pacientes (Grupo 1) e desempenho normal em 47 pacientes (Grupo 2). Em comparação aos pacientes do Grupo 2, os pacientes do Grupo 1 apresentaram menor idade (p<0,001), menor idade de diagnóstico das bronquiectasias (p=0,006), menor proporção de ex fumantes (p=0,048), menor índice de massa corporal (IMC) (p=0,003), pior VEF1 % previsto (p=0,041) e pior pressão expiratória máxima % previsto (p=0,021). Não houve diferença significante entre grupos nos escores de QVRS (p>0,05). No modelo de regressão logística, idade menor (p=0,002) e IMC menor (p=0,034) se associaram significantemente com desempenho precário no TC6M. Conclusão: Elevada proporção de pacientes com bronquiectasias não fibrocísticas apresenta desempenho precário no TC6M. O desempenho ao exercício não se relacionou com a QVRS. Idade e IMC se associaram com performance ao exercício. / Objective: To determine the performance in 6-minute walk test (6MWT) in adult patients with non-cystic fibrosis bronchiectasis, establishing the relationship between 6-MWT and health-related quality of life (HRQL). Secondarily, to determine the relationship between 6MWT, clinical findings and lung function in order to identify predictors for exercise tolerance. Methods: Cross-sectional study involving patients with non-cystic fibrosis bronchiectasis aged ≥ 18 years, with at least one respiratory symptom for 2 years or more, and with predicted forced expiratory volume in first second (FEV1) ≤ 70%. Patients were submitted to clinical evaluation, pulmonary function tests, 6MWT and HRQL using the Short-Form 36 Questionnaire. Results: Seventy patients were included (48 females; mean age, 54.5±17.7 years; mean FEV1, 44.9 ±14.5%). We observed poor performance in 6MWT in 23 patients (Group 1) and normal performance in 47 patients (Group 2). In comparison with Group 2 patients, Group 1 patients presented lower age (p<0.001), lower age at diagnosis of bronchiectasis (p=0.006), lower proportion of ex-smokers (p=0.048), lower body mass index (BMI) (p=0.003), worse FEV1 % predicted (p=0.041), and worse maximum expiratory pressure % predicted (p=0.021). There was no significant difference between groups on scores for HRQL (p>0.05). In a logistic regression model, lower age (p=0.002) and lower BMI (p=0.034) were significantly associated with poor performance in 6MWT. Conclusion: There is a high rate of poor performance in 6MWT in patients with non-cystic fibrosis bronchiectasis. The exercise performance was not related to HRQL. Age and BMI were associated with the exercise performance.
230

Efektivita finančního trhu / Financial market efficiency

KOPTIŠ, Daniel January 2018 (has links)
This diploma thesis analyses the market efficiency hypothesis of chosen currency pairs EUR/USD, EUR/CZK and USD/CZK. The aim of this study is to describe the price behaviour of chosen financial assets and verify the random walk hypothesis on the foreign exchange market. Model of random walk says there is no relationship between historical and future prices, so price changes are random and cannot be predicted. Random walk hypothesis was tested by chosen statistic tests runs test, test of auto-correlation, variance ratio test and unit root test (Augmented Dickey-Fuller Test). Data were collected through the online trading platform and tested in EViews. Period of testing for daily changes (D1) was chosen from 31.12.2009 to 29.12.2017 and for weekly changes (T1) from 2.1.2005 to 29.12.2017. This thesis proved weak-form efficiency of EUR/USD and USD/CZK for both daily changes and weekly changes in a chosen period. Inefficient behaviour of daily changes of EUR/CZK (D1) was indicated by runs test, test of autocorrelation and variance ratio test. There is a question what the cause of inefficiency is. The most likely explanation is currency intervention of the Czech National Bank which took place from April 2013 to April 2017 in order to achieve the inflation target and prevent deflation. Traders could also achieve profits by speculating on appreciation of Czech Crown below 27,-crowns/euro which is not in harmony with efficient-market hypothesis. Moreover, currency pair EUR/CZK is not liquid as major currency pairs and there are bigger transaction costs because of bid-offer spread. This work can contribute to next research in connection with results of this study. To verify if the cause of inefficient behaviour of daily price changes of EUR/USD are currency interventions of the Czech National Bank, I would suggest testing efficient-market hypothesis exactly at the time of interventions. It would be also suitable to compare results of different methodologies including testing in short-time intervals of price changes.

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