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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.
111

Analýza vztahu použitých obranných systémů a charakteristik rychlého útoku u vybraného družstva házené / Analysis of defence systems and attributes of fast attack used for selected handbal team.

Jelínek, Roman January 2017 (has links)
Title: Analysis of defence systems and attributes of fast attack used for selected handbal team. Objectives: The objective of my dissertation was to find out reciprocal relations between defence systems and quantity (quality also) attributes of fast attack used for top handbal team in Czech republic. My next objective was analyzation of recorded values and comparation with available values of national teams from top events like Olympic games, European and World championship. Methods: We used for our dissertation methods of direct observation, indirect observation and analyzation. The results were processed by Microsoft office Excel 2007 and there was used chi-squared distribution of independence. Results: We found out in our dissertation that the observed team was frequently in fast attack during more agresive zone defence system 1:5 than the other defence systems used during games in season 2015/2016. The next detection is that observed team had almost the same quantity of fast attacks in one game like national teams during big international tournaments but there was found a big difference in proportional success of attacks for national teams. The participation of goals from fast attacks and total attacks is bigger for our observed team than for national teams on big international tournaments but...
112

Porovnání biologického proporcionálního věku a teoretického kostního věku na příkladu plavců / Comparison of proportional biological age and theoretical skeletal age on the example of swimmers

Peřinka, Filip January 2014 (has links)
and key words Problem definition: Assessment of the biological age is possible to obtain by several methods, both simple and more sophisticated. Results will surely not always comport. Currently radiography of distal epiphysis antebrachia and ossa manus (ossa carpi , ossa metacarpi, phalanges) is considered to be the most exact method, however for the reason of unavailability of X-ray pictures, we require for assessment of the bone age, this method is used exceptionally mainly for its invasiveness. Theoretical estimation of the bone age might be a kind of alternative method when assessed from derived coefficients of regression equations, made on a base of conventional radiographic method. In the contrast of that, age rating by biological proportionality is considered a substitution of the bone age criteria. So, the problem is the mutual diversity and difference of the two methods which are relatively most exact. The Aim: In the thesis, we deal with comparison of the biological proportional age and theoretical bone age within swimming youth, in age range 11-15 years altogether. The main goal is to learn the difference of the biological maturity by using two methods determining the biological age coming out from anthropological measurement of individuals. Methods of resolution: Assessment of the...
113

A study of the robustness of Cox's proportional hazards model used in testing for covariate effects

Fei, Mingwei January 1900 (has links)
Master of Arts / Department of Statistics / Paul Nelson / There are two important statistical models for multivariate survival analysis, proportional hazards(PH) models and accelerated failure time(AFT) model. PH analysis is most commonly used multivariate approach for analysing survival time data. For example, in clinical investigations where several (known) quantities or covariates, potentially affect patient prognosis, it is often desirable to investigate one factor effect adjust for the impact of others. This report offered a solution to choose appropriate model in testing covariate effects under different situations. In real life, we are very likely to just have limited sample size and censoring rates(people dropping off), which cause difficulty in statistical analysis. In this report, each dataset is randomly repeated 1000 times from three different distributions (Weibull, Lognormal and Loglogistc) with combination of sample sizes and censoring rates. Then both models are evaluated by hypothesis testing of covariate effect using the simulated data using the derived statistics, power, type I error rate and covergence rate for each situation. We would recommend PH method when sample size is small(n<20) and censoring rate is high(p>0.8). In this case, both PH and AFT analyses may not be suitable for hypothesis testing, but PH analysis is more robust and consistent than AFT analysis. And when sample size is 20 or above and censoring rate is 0.8 or below, AFT analysis will have slight higher convergence rate and power than PH, but not much improvement in Type I error rates when sample size is big(n>50) and censoring rate is low(p<0.3). Considering the privilege of not requiring knowledge of distribution for PH analysis, we concluded that PH analysis is robust in hypothesis testing for covariate effects using data generated from an AFT model.
114

EMG-driven exoskeleton control. / Controle de exoesqueleto baseado em EMG.

Sommer, Leonardo Fischi 17 May 2019 (has links)
The need for mechanisms that assist human movements has been increasing due to the rising number of people that has some kind of movement disability. In this scenario, it is of great importance the development of control methods that assist the interface between a motor assistive device and its user. This work proposes a controller for an exoskeleton with one degree of freedom, using surface electromyography signals from the user as the input signal. An exoskeleton was adapted to serve as platform for the developed control method. To create an EMG-to-Angle model, a set of experiments were carried out with six subjects. The experiment consisted of a series of continuous and discrete elbow flexion and extension movements with different load levels. Using the experimental data, linear (ARIMAX) and non linear (Hammerstein-Wiener) system identification methods were evaluated to determine which is the best candidate for the estimation of the EMG-to-Angle model, based on its accuracy and ease of implementation. A new experiment wasconducted to develop a real-time controller, based on FIR model and tested in a real-timeapplication. Tests showed that the controller is capable of estimating the elbow joint angle with correlation above 70% and root-mean-square error below 25° when compared to the measured elbow joint angles. / A necessidade por mecanismos que auxiliam os movimentos do ser humano vem crescendo devido ao aumento do número de pessoas portadores de deficiências que afetam a capacidade motora. Nesse cenário, é de grande importância o desenvolvimento de métodos de controle que auxiliem a interface entre o dispositivo de assistência motora e o seu usuário. Esse trabalho propõe um controlador para um exoesqueleto com um grau de liberdade, usando sinais de eletromiografia de superfície do usuário como sinal de entrada. Um exoesqueleto foi adaptado para servir de plataforma para o método de controle desenvolvido. Para criar um modelo EMG-ângulo, um conjunto de experimentos foi conduzido com seis voluntários. O experimento consistiu em uma série de movimentos de flexo-extensão do cotovelo contínuos e discretos com diferentes níveis de carga. Utilizando os dados do experimento, métodos de identificação de sistemas linear (ARIMAX) e não linear (Hammerstein-Wiener) foram avaliados para determinar qual o melhor candidato para a estimação do modelo EMG-ângulo, baseado em sua acurácia e facilidade de implementação. Um novo experimento foi conduzido para desenvolver um controlador em tempo real, baseado no modelo FIR e testado em uma aplicação em tempo real. Testes indicaram que o controlador é capaz de estimar o ângulo da junta do cotovelo com valores de correlação acima de 70% e raiz do erro quadrático médio menor que 25º, quando comparados aos valores medidos de ângulo da junta do cotovelo.
115

Predeterminantes de sobrevivência em vítimas de acidentes de trânsito submetidas a atendimento pré-hospitalar de suporte avançado à vida / Survival determinant factors in motor vehicle crash victms submitted to prehospital advanced life support

Malvestio, Marisa Aparecida Amaro 15 December 2005 (has links)
O Atendimento Pré Hospitalar (APH) é um importante recurso no atendimento à vítimas de trauma. No entanto, há muitas dificuldades para demonstrar o efeito benéfico das intervenções do APH na sobrevivência das vítimas, sobretudo as de suporte avançado à vida (SAV). A proposta deste estudo é caracterizar as vítimas de acidentes trânsito, com Revised Trauma Score (RTS) <11, atendidas pelo SAV municipal e encaminhadas a hospitais terciários em São Paulo, além de identificar as variáveis da fase pré-hospitalar associadas à sobrevivência e avaliar o valor predeterminante dessas variáveis sobre o resultado obtido pelas vítimas. As variáveis avaliadas foram: sexo, idade, mecanismos do acidente, procedimentos de suporte básico e SAV realizados, repercussão fisiológica do trauma na cena do acidente, (considerando o RTS , seus parâmetros e flutuações), o tempo consumido no APH, gravidade do trauma segundo o Injury Severity Score (ISS),a Maximum Abbreviated Injury Scale (MAIS) e número de lesões para cada segmento corporal. Os resultados obtidos por 175 vítimas entre 12 e 65 anos, foram submetidos a "Análise de Sobrevivência de Kaplan Meier" e ao “Modelo de Riscos Proporcionais de Cox". A variável dependente foi o tempo de sobrevivência após o acidente, considerando os intervalos até 6h,12h, 24h, 48h, até 7 dias e até o término da internação. Os homens (86,9%) e a faixa etária de 20 a 29 anos (36,0%) foram as mais freqüentes. Os atropelamentos (45,1%) e o envolvimento de motocicletas e seus ocupantes (30,9%) foram os destaques dentre os mecanismos de trauma. A média do RTS na cena e do ISS, foram respectivamente 8,8 e 19,4.Os segmentos corpóreos mais atingidos foram: cabeça (58,8%), membros inferiores (45,1%) e superfície externa (40%). A média de tempo consumido na fase de APH foi 41min (tempo de cena 20,2min). Ocorreram 36% de óbitos, (metade em até 6 horas). A análise estatística revelou 24 fatores associados à sobrevivência, dentre eles, os procedimentos respiratórios avançados e os circulatórios básicos, as variáveis relativas ao RTS e a gravidade (ISS, MAIS e o número de lesões). No modelo final de Cox, ter sido submetido a procedimentos respiratórios avançados, compressões torácicas, apresentar lesão abdominal e ISS>25, foi associado a maior risco para o óbito até 48h após o trauma. Até 7 dias, a compressão torácica não se manteve no modelo final e a PAS de zero a 75mmHg apresentou associação com a morte após o acidente. Até a alta hospitalar, a ausência de PAS na avaliação inicial permaneceu no modelo. A reposição de volume foi o único fator com valor protetor para o risco de óbito presente em todos os momentos / The prehospital care (PH) is an important resource to trauma victims’ care. Nevertheless, there is great difficulty in demonstrating the PH intervention’s positive effect in victim’s survival, especially when concerning the advanced life support (ALS). The aim of this study is to characterize motor vehicle crash victims with Revised Trauma Score (RTS) <11 cared by municipal ALS and moved to tertiary hospitals in São Paulo in addition to identifying the prehospital variables associated to survival, and to evaluate their values as victim survival outcome determinant. The variables evaluated were: sex, age, trauma mechanism, basic life support and ALS procedures, physiological measures in the accident scene (considering the RTS, its parameters and fluctuations), the time consumed in PH phase, trauma severity by Injury Severity Score (ISS), the Maximum Abbreviated Injury Scale (MAIS) and number of lesions in each body region. The main results obtained by 175 victims between 12 e 65 years of age were submitted to the Kaplan Meier Survival Analysis and to Cox Proportional hazards Regression Analysis. The dependent variable was the survival time after the motor vehicle accident considering the intervals up to 6,12,24 and 48hs , up to 7 days and until the time of hospital discharge. Men (86,9%) and the 20 to 29 aged group (36%) were the most frequent. The pedestrians struck by car (45,1%) and the motorcycles (and their riders) (30,9%)were the highlight in trauma mechanisms. The RTS and the ISS average were 8,8 and 19,4 respectively. The more damaged body regions were head (58,8%), lower limbs (45,1%) and external surface (40%).The prehospital time average was 41 min (scene time 20,2min).Death rate was 36% (half of which up to 6hs).The statistical analysis revealed 24 survival associated factors. The ALS and the circulatory basic procedures, the RTS variables and the trauma severity (ISS,MAIS and number of lesions) were within them. In the final Cox Model were associated to higher risk of death up to 48hs after trauma: the submission to ALS respiratory procedures, chest compressions, the presence of abdominal injuries and ISS>25 .Until the 7th day the chest compression was not sustained in a final model and the systolic blood pressure (SBP) from zero to 75mmHg revealed statistical association with death after trauma. Until hospital discharge the SBP absence in scene evaluation remained in the model. The prehospital intravenous fluid refilling was the only factor of protector value to death risk in all moments
116

Comparação entre alguns métodos estatísticos em análise de sobrevivência: aplicação em uma coorte de pacientes com câncer de pênis / Comparison of some statistical methods in survival analysis: application in a cohort of patients with penile cancer

Latorre, Maria do Rosario Dias de Oliveira 05 June 1996 (has links)
O objetivo deste trabalho foi comparar o desempenho do modelo de riscos proporcionais de Cox convencional, modelo de Cox modificado quando os riscos não são proporcionais e o modelo de análise de sobrevida baseado na teoria de processos de contagem. Para tanto utilizou-se uma coorte de 648 pacientes portadores de câncer de pênis, atendidos no Departamento de Cirurgia Pélvica do Hospital A. C. Camargo, no período de 1953 a 1985. Dessa coorte foram selecionadas três amostras com o objetivo de validar internamente os resultados da análise de sobrevida do banco de dados original. Os resultados do modelo de riscos proporcionais de Cox, no banco de dados original, foram confirmados por uma das amostras desse conjunto de dados. Apenas o estadiamento N foi confirmado como fator prognóstico também nas outras duas amostras. O modelo de riscos proporcionais de Cox e o modelo de análise de sobrevida baseado na teoria de processos de contagem apresentaram resultados semelhantes, na definição dos fatores prognósticos dessa coorte de pacientes com câncer de pênis. O modelo utilizando processos de contagem é mais sofisticado, do ponto de vista matemático. Porém o modelo de Cox está disponível em grande número de pacotes estatísticos e a interpretação de seus coeficientes se faz com maior facilidade. Por isso, talvez, continue a ser a técnica estatística mais utilizada quando o objetivo do estudo é definir fatores prognósticos e grupos de risco. Os fatores prognósticos para a sobrevida de pacientes com câncer de pênis foram os estadiamentos T e N e o grau de diferenciação do tumor. Esses resultados foram ajustados pelo ano de início de tratamento no Hospital A.C. Camargo. Os pacientes com prognóstico favorável foram os que apresentaram tumor pequeno, sem presença de linfonodos clinicamente positivos, e tumor bem diferenciado. / The aim of this study was to compare the performance of the Cox proportional hazards model, the Cox model with time-dependent covariates and the survival model using the counting process theory. These methods were applied in a cohort of 648 patients with penile cancer treated at the Department of Pelvic Surgery, Hospital A.C. Camargo (São Paulo-Brazil), between 1953 and 1985. Three samples were selected from the total database in order to check the internal validity. The prognostic factors selected using the Cox proportional hazards model were the same in one sample. The only prognostic factor selected in all samples was the N stage. The T and N stages, and the grade of differentiation were independent prognostic factors of survival using both the Cox proportional hazards model and the survival,model using the counting process theory. The statistical significance was the same and even the values of estimation of the coefficients were very close. The survival model using the counting process is more sophisticated from the mathematical point of view, but the Cox model is more available in statistical software, and, probably because of this, is more applied in survival analysis than the model using the counting processo Patients with small tumors, clinically negatives nodes and well differentiated tumors showed a favorable prognosis. These results were adjusted by year of the beginning in the study.
117

Simulação de modelos dinâmicos com amortecimento não-proporcional / Dynamic simulations of mechanical systems with non-proportional damping

Ana Lúcia Grici Zacarin Mamede 15 December 2008 (has links)
Alguns métodos aproximados são sugeridos na literatura relacionada para encontrar a resposta de sistemas com amortecimento não-proporcional. Muitas vezes procura-se estabelecer um critério para aproximar o amortecimento não-proporcional por um modelo de amortecimento proporcional. Neste trabalho foram utilizadas simulações de modelos dinâmicos com três graus de liberdade, com amortecimento não proporcional, a fim de analisar os valores obtidos para as freqüências naturais, estimados a partir dos autovalores resultantes desses modelos. Os cálculos das freqüências naturais e dos amortecimentos modais foram feitos admitindo-se a validade das relações entre estes parâmetros e os autovalores do problema como são bem conhecidas no caso do amortecimento proporcional. Observa-se que, para o caso de amortecimento não-proporcional, este procedimento pode levar a erros significativos na avaliação destes parâmetros. Nos problemas simulados é possível quantificar os erros nas avaliações das freqüências naturais, sendo significativos para fatores de amortecimentos altos. Observa-se que para os fatores de amortecimento não é possível quantificar estes erros, sendo que seus valores são apenas aproximações baseadas na teoria de amortecimento proporcional. Este trabalho apresenta dados que possibilitam uma discussão sobre as diferenças encontradas entre os valores das freqüências naturais e os valores estimados pelas expressões clássicas do amortecimento proporcional. / Some approximate methods are suggested in the related literature to find the output of mechanical systems with non-proportional damping. Often they try to establish a criterion that approximates the non-proportional damping to proportional damping model. In this work, stimulations of dynamics models of three degree of freedom with non-proportional damping were used to examine the values of natural frequencies, estimated from the eigenvalues obtained by these models. The calculations of natural frequencies and modal damping ratio were performed assuming the validity of the relationship between these parameters and the well known eigenvalues of the problem in the proportional damping case. In the simulated problems is possible to quantify the errors in the evaluations of the natural frequencies and this errors are significant for the case where the damping factors are high. It is observed that for the damping factors it is not possible to quantify these errors, and their magnitudes are only approximations based on the theory of proportional damping. This work presents data which enables a discussion about the differences between the magnitude of natural frequencies and the magnitude estimated by the classic equations of proportional damping.
118

Hardware de ventilador pulmonar. / Hardware lung ventilator.

Silva, Alexandre Rodrigues da 27 September 2011 (has links)
Este trabalho visou mostrar o desenvolvimento de um ventilador pulmonar mecânico, focando principalmente na parte de hardware necessária para que este equipamento pudesse funcionar. Ventilação mecânica é a modalidade da medicina mais importante no cuidado a pacientes criticamente enfermos. O ventilador é um equipamento utilizado principalmente em unidades de terapia intensiva, que basicamente coloca uma mistura de ar e oxigênio para dentro do pulmão de um paciente incapacitado de fazer isto naturalmente, quer seja por força de uma doença que o impossibilita de fazê-lo, ou por uma cirurgia, a qual impossibilitou o movimento do músculo do diafragma para que o ar entrasse no pulmão naturalmente. Este projeto cobriu uma descrição abrangente sobre este ventilador, sua transformação de ar comprimido e oxigênio provenientes de um cilindro em uma mistura controlada de fluxos que entra no pulmão para a inspiração de um volume, ou para atingir uma pressão determinada, e a saída desta mistura, mantendo no pulmão uma pressão também controlada. Foi desenvolvido um protótipo de hardware e firmware para este aparelho, e o intuito foi mostrar o processo de transformação da ideia inicial e as necessidades de projeto em um aparelho testado e certificado para uso no mercado. / This work aimed to present the development of a pulmonary mechanical ventilator, mainly focusing on the hardware part needed in order for this device to work. Mechanical ventilation is the most important medical mode concerning the care of patients that are critically ill. The ventilator is a device very much used in intensive care units (ICUs), and it basically delivers an air and oxygen mixture to the patients lungs that is normally unable to do so naturally, either because the patient is seriously ill that prevents him/her to do so, or due to surgery, in this case prevented the movement of the diaphragm muscle so the air could be naturally delivered to the lung. This work covered a comprehensive description about this ventilator, its transformation of compressed air and oxygen coming from a cylinder in a controlled mixture of flows that enters the lung for the inspiration of a volume, or to achieve a determined pressure, and the output of this mixture, maintaining a controlled pressure in the lung too. A hardware and firmware prototype was developed for this device. The aim was to show the transformation process from the main idea and the need for a project of a tested and certified device to be used in the market.
119

Semiparametric Estimation of a Gaptime-Associated Hazard Function

Teravainen, Timothy January 2014 (has links)
This dissertation proposes a suite of novel Bayesian semiparametric estimators for a proportional hazard function associated with the gaptimes, or inter-arrival times, of a counting process in survival analysis. The Cox model is applied and extended in order to identify the subsequent effect of an event on future events in a system with renewal. The estimators may also be applied, without changes, to model the effect of a point treatment on subsequent events, as well as the effect of an event on subsequent events in neighboring subjects. These Bayesian semiparametric estimators are used to analyze the survival and reliability of the New York City electric grid. In particular, the phenomenon of "infant mortality," whereby electrical supply units are prone to immediate recurrence of failure, is flexibly quantified as a period of increased risk. In this setting, the Cox model removes the significant confounding effect of seasonality. Without this correction, infant mortality would be misestimated due to the exogenously increased failure rate during summer months and times of high demand. The structural assumptions of the Bayesian estimators allow the use and interpretation of sparse event data without the rigid constraints of standard parametric models used in reliability studies.
120

Simulação de modelos dinâmicos com amortecimento não-proporcional / Dynamic simulations of mechanical systems with non-proportional damping

Mamede, Ana Lúcia Grici Zacarin 15 December 2008 (has links)
Alguns métodos aproximados são sugeridos na literatura relacionada para encontrar a resposta de sistemas com amortecimento não-proporcional. Muitas vezes procura-se estabelecer um critério para aproximar o amortecimento não-proporcional por um modelo de amortecimento proporcional. Neste trabalho foram utilizadas simulações de modelos dinâmicos com três graus de liberdade, com amortecimento não proporcional, a fim de analisar os valores obtidos para as freqüências naturais, estimados a partir dos autovalores resultantes desses modelos. Os cálculos das freqüências naturais e dos amortecimentos modais foram feitos admitindo-se a validade das relações entre estes parâmetros e os autovalores do problema como são bem conhecidas no caso do amortecimento proporcional. Observa-se que, para o caso de amortecimento não-proporcional, este procedimento pode levar a erros significativos na avaliação destes parâmetros. Nos problemas simulados é possível quantificar os erros nas avaliações das freqüências naturais, sendo significativos para fatores de amortecimentos altos. Observa-se que para os fatores de amortecimento não é possível quantificar estes erros, sendo que seus valores são apenas aproximações baseadas na teoria de amortecimento proporcional. Este trabalho apresenta dados que possibilitam uma discussão sobre as diferenças encontradas entre os valores das freqüências naturais e os valores estimados pelas expressões clássicas do amortecimento proporcional. / Some approximate methods are suggested in the related literature to find the output of mechanical systems with non-proportional damping. Often they try to establish a criterion that approximates the non-proportional damping to proportional damping model. In this work, stimulations of dynamics models of three degree of freedom with non-proportional damping were used to examine the values of natural frequencies, estimated from the eigenvalues obtained by these models. The calculations of natural frequencies and modal damping ratio were performed assuming the validity of the relationship between these parameters and the well known eigenvalues of the problem in the proportional damping case. In the simulated problems is possible to quantify the errors in the evaluations of the natural frequencies and this errors are significant for the case where the damping factors are high. It is observed that for the damping factors it is not possible to quantify these errors, and their magnitudes are only approximations based on the theory of proportional damping. This work presents data which enables a discussion about the differences between the magnitude of natural frequencies and the magnitude estimated by the classic equations of proportional damping.

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