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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.
81

AS DUALIDADES BEM/MAL E BELO/FEIO NA CONSTRUÇÃO DISCURSIVA DO SACI-PERERÊ EM MONTEIRO LOBATO

Lima, Patrícia de Oliveira Pereira 04 June 2009 (has links)
Made available in DSpace on 2016-03-22T17:26:17Z (GMT). No. of bitstreams: 1 Patricia_final.pdf: 829347 bytes, checksum: b9a0dcfb887261d7fa520aa7e460dc1f (MD5) Previous issue date: 2009-06-04 / This work investigates the relationship body/language through the discursive construction of the character One-legged man, in the book One-legged man, by Monteiro Lobato, considering the present ambivalence in its constitution as for the binomial beautiful/good and ugly/bad. For this, it tries to verify as the intra and interdiscursive elements link to that subject with base in the theoretical referential of the Analysis of Speech of French line, interpretative science that deals with issues related to the socio-historical process of production of the senses. The dicotomic relationships were analyzed by the observation of indicative elements in the selected discursive cuttings, sending them to the elements of the discursive memory. The intra and interdiscursive mechanisms involved in this relationship allowed to evidence present contradictory aspects in that character's constitution, producing different sense effects / Este trabalho investiga a relação corpo/linguagem por meio da construção discursiva da personagem Saci, na obra O Saci, de Monteiro Lobato, considerando a ambivalência presente em sua constituição quanto ao binômio belo/bem e feio/mal. Para tanto, procura verificar como os elementos intra e interdiscursivos relacionam-se a essa questão com base no referencial teórico da Análise de Discurso de linha francesa, ciência interpretativa que se ocupa de questões ligadas ao processo sócio-histórico de produção dos sentidos. As relações dicotômicas foram analisadas mediante a observação de elementos designativos nos recortes discursivos selecionados, remetendo-os aos elementos da memória discursiva. Os mecanismos intra e interdiscursivos envolvidos nessa relação permitiram evidenciar aspectos contraditórios presentes na constituição dessa personagem, produzindo diferentes efeitos de sentido
82

Efeitos fisiológicos do treinamento unipodal em cicloergômetro com e sem irradiação LED / Physiological effects of one-legged cycling with and without LED therapy

Figueira, Thiago Gomes 01 December 2017 (has links)
A melhora na capacidade física e/ou reserva funcional de um indivíduo deve-se, entre outros, a um treinamento sistemático e bem padronizado. O exercício aeróbio é uma modalidade frequentemente empregada em um programa de treinamento, especialmente naqueles com objetivo de melhora do condicionamento físico. Contudo atualmente, o uso da fototerapia tem ganhado espaço no que tange ao aumento de desempenho de atletas. Baseado nisso o objetivo deste estudo foi verificar o efeito do treinamento unipodal, terapia LED e treinamento associado à terapia LED sobre parâmetros ergoespirométricos de performance (VO2max, AT e RCT) e na concentração sanguínea de creatina quinase. Para esse estudo participaram 24 voluntários do sexo masculino, os quais foram submetidos a uma avaliação pré-intervenção, foram submetidos a um período de oito semanas de treinamento em cicloergômetro com irradiação LED ou placebo. Após esse período foram submetidos a uma nova avaliação, pós-treino. Para a aplicação da terapia LED, foi utilizado um arranjo contendo 50 LEDs com comprimento de onda de 850 nm e aplicado por 60 segundos após cada sessão de treino. Os voluntários foram separados nos seguintes grupos experimentais: Não Treinados e LED desligado (Grupo NTLD), Não Treinados e LED ligado (Grupo NTLL), Treinados e LED desligado (Grupo TLD), Treinados e LED ligado (Grupo TLL). A perna que recebeu a intervenção foi eleita por sorteio e foi chamada de perna ativa (A) e a perna contralateral, chamada de controle (C). Durante o teste em exercício crescente, até a fadiga, foram quantificadas as variáveis ergoespirométricas, ventilação (Ve), consumo de oxigênio (VO2), equivalente ventilatório de oxigênio (EqVO2), também foi coletada amostra de sangue para dosagem da lactacidemia e foi mensurada a concentração da enzima creatina quinase (CK). Como resultados das respostas agudas frente ao ato de pedalar com uma perna notou-se que a pedalada unipodal apresentou menor valor de intensidade, VO2, Ve, lactacidemia e maior incremento de CK, quando comparada com a pedalada bipodal (convencional). Ao se concluir as oito semanas de treinamento notou-se que a perna ativa na pedalada unipodal apresentou melhoras nas variáveis mensuradas nos grupos TLL, NTLL e algumas no TLD. Também foi encontrada melhora para a perna controle, em algumas variáveis, dos grupos que receberam a terapia LED. Com esse estudo conclui-se que o treinamento unipodal é capaz de melhorar parâmetros como intensidade, ventilação, consumo de oxigênio, eficiência aeróbia, e ainda minimiza os danos musculares induzido pelo exercício no membro que efetuou o treinamento. A terapia LED é capaz de promover as mesmas melhoras em intensidades, consumo de oxigênio e eficiência aeróbia que o treinamento proporcionou, contudo em magnitudes diferentes, ainda é capaz de proporcionar efeito protetor contra lesão muscular induzida pelo exercício. A terapia LED associada ao treinamento potencializa os efeitos conseguidos com cada um isoladamente. / The improvement in physical capacity and/or functional reserve is due to, among other factors, a systematic and organized training program. Aerobic exercise is a frequently used modality in a training program, especially among those who aim to improve physical fitness. However phototherapy has currently gained space in regard to improving the performance of athletes. Based on this information, the purpose of the study was to verify the effect of one-legged cycling, LED therapy and their association on ergospirometric parameters of performance (VO2max, AT and RCT) and on blood concentration of CK. 24 male subjects volunteered for the study and were submitted to a pre-intervention evaluation and an 8-week period of one-legged cycling with LED therapy or placebo. After the intervention period subjects were submitted to a second evaluation. An arrangement containing 50 LEDs and a wavelength of 850 nm was applied during 60 seconds after each training session. Volunteers were divided into the following experimental groups: untrained and LED off (ULOf), untrained and LED on (ULOn), trained and LED off (TLOf) and trained and LED on (TLOn). The leg that received the intervention (training and/or LED therapy) was selected randomly and named active leg (A) and the contralateral limb was named control (C). During the incremental exercise test to volitional failure the ergospirometric variables ventilation (Ve), oxygen uptake (VO2) and oxygen ventilatory equivalent (EqVO2) were measured and blood samples were collected after each stage for lactate and before and 24 hours after the test for the analysis of blood CK. Acute responses from the pre-intervention evaluation showed that the intensity of one-legged cycling led to lower intensity, VO2, Ve, blood lactate and higher increase in blood CK compared to traditional cycling (two-legged). After the 8 weeks of intervention, the active leg showed improvements in the measured variables for the TLOn, ULOn and TLOf groups and, in some of the variables for the groups that received LED therapy. With these data we conclude that one-legged cycling is capable of increasing parameters such as intensity, ventilation, oxygen uptake, aerobic efficiency and minimizes the blood CK responses to exercise in the exercised limb. The association between exercise and Led therapy potentiates the effects achieved with either of the interventions.
83

Applications of active materials

Edqvist, Erik January 2009 (has links)
Energy efficiency is a vital key component when designing and miniaturizing self sustained microsystems. The smaller the system, the smaller is the possibility to store enough stored energy for a long and continuous operational time. To move such a system in an energy efficient way, a piezoelectrical locomotion module consisting of four resonating cantilevers has been designed, manufactured and evaluated in this work. The combination of a suitable substrate, a multilayered piezoelectric material to reduce the voltage, and a resonating drive mechanism resulted in a low power demand. A manufacturing process for multilayer cantilever actuators made of P(VDF-TrFE) with aluminum electrodes on a substrate of flexible printed circuit board (FPC), has been developed. An important step in this process was the development of an etch recipe for dry etching the multilayer actuators in an inductive plasma equipment. Formulas for the quasi static tip deflection and resonance frequency of a multilayered cantilever, have been derived. Through theses, it was found that the multilayered structures should be deposited on the polymer side of the FPC in order to maximize the tip deflection. Both a large and a miniaturized locomotion module were manufactured and connected by wires to verify that the three legged motion principal worked to move the structures forward and backward, and turn it right and left. By touching and adding load, to a fourth miniaturized cantilever, its ability to act as a contact sensor and carry object was verified. The presented locomotion module is part of a multifunctional microsystem, intended to be energy efficient and powered by a solar panel with a total volume of less than 25 mm3 and weight 65 mg. The whole system, consisting of a solar cell, an infra red communication module, an integrated circuit for control, three capacitors for power regulating, the locomotion module and an FPC connecting the different modules, was surface mounted using a state of the art industrial facility. Two fully assembled systems could be programmed both through a test connector and through optical sensors in the multifunctional solar cell. One of these was folded together to the final configuration of a robot. However, the entire system could not be tested under full autonomous operating conditions. On the other hand, using wires, the locomotion module could be operated and used to move the entire system from a peak-to-peak voltage of 3.0 V.
84

A Foot Placement Strategy for Robust Bipedal Gait Control

Wight, Derek L. 09 May 2008 (has links)
This thesis introduces a new measure of balance for bipedal robotics called the foot placement estimator (FPE). To develop this measure, stability first is defined for a simple biped. A proof of the stability of a simple biped in a controls sense is shown to exist using classical methods for nonlinear systems. With the addition of a contact model, an analytical solution is provided to define the bounds of the region of stability. This provides the basis for the FPE which estimates where the biped must step in order to be stable. By using the FPE in combination with a state machine, complete gait cycles are created without any precalculated trajectories. This includes gait initiation and termination. The bipedal model is then advanced to include more realistic mechanical and environmental models and the FPE approach is verified in a dynamic simulation. From these results, a 5-link, point-foot robot is designed and constructed to provide the final validation that the FPE can be used to provide closed-loop gait control. In addition, this approach is shown to demonstrate significant robustness to external disturbances. Finally, the FPE is shown in experimental results to be an unprecedented estimate of where humans place their feet for walking and jumping, and for stepping in response to an external disturbance.
85

A Foot Placement Strategy for Robust Bipedal Gait Control

Wight, Derek L. 09 May 2008 (has links)
This thesis introduces a new measure of balance for bipedal robotics called the foot placement estimator (FPE). To develop this measure, stability first is defined for a simple biped. A proof of the stability of a simple biped in a controls sense is shown to exist using classical methods for nonlinear systems. With the addition of a contact model, an analytical solution is provided to define the bounds of the region of stability. This provides the basis for the FPE which estimates where the biped must step in order to be stable. By using the FPE in combination with a state machine, complete gait cycles are created without any precalculated trajectories. This includes gait initiation and termination. The bipedal model is then advanced to include more realistic mechanical and environmental models and the FPE approach is verified in a dynamic simulation. From these results, a 5-link, point-foot robot is designed and constructed to provide the final validation that the FPE can be used to provide closed-loop gait control. In addition, this approach is shown to demonstrate significant robustness to external disturbances. Finally, the FPE is shown in experimental results to be an unprecedented estimate of where humans place their feet for walking and jumping, and for stepping in response to an external disturbance.
86

Six-legged Walking Machine: The Robot-ea308

Erden, Mustafa Suphi 01 July 2006 (has links) (PDF)
The work presented in this thesis aims to make contribution to the understanding and application of six-legged statically stable walking machines in both theoretical and practical levels. In this thesis five pieces of work, performed with and for the three-joint six-legged Robot-EA308, are presented: 1) Standard gaits, which include the well-known wave gaits, are defined and a stability analysis, in the sense of static stable walking, is performed on an analytical level. Various definitions are given / theorems are stated and proved. 2) A free gait generation algorithm with reinforcement learning is developed. Its facilities of stability improvement, smooth speed changes, and adaptation in case of a rear-leg deficiency with learning of five-legged walking are experimented in real-time on the Robot-EA308. 3) Trajectory optimization and controller design is performed for the protraction movement of a three-joint leg. The trajectory generated by the controller is demonstrated with the Robot-EA308. 4) The full kinematic-dynamic formulation of a three-joint six-legged robot is performed with the joint-torques being the primary variables. It is demonstrated that the proposed torque distribution scheme, rather than the conventional force distribution, results in an efficient distribution of required forces and moments to the supporting legs. 5) An analysis of energy efficiency is performed for wave gaits. The established strategies for determination of gait parameters for an efficient walk are justified using the Robot-EA308.
87

Control Of Hexapedal Pronking Through A Dynamically Embedded Spring Loaded Inverted Pendulum Template

Ankarali, Mustafa Mert 01 February 2010 (has links) (PDF)
Pronking is a legged locomotory gait in which all legs are used in synchrony, usually resulting in slow speeds but long flight phases and large jumping heights that may potentially be useful for mobile robots locomoting in cluttered natural environments. Instantiations of this gait for robotic systems suffer from severe pitch instability either due to underactuated leg designs, or the open-loop nature of proposed controllers. Nevertheless, both the kinematic simplicity of this gait and its dynamic nature suggest that the Spring-Loaded Inverted Pendulum Model (SLIP), a very successful predictive model for both natural and robotic runners, would be a good basis for more robust and maneuverable robotic pronking. In the scope of thesis, we describe a novel controller to achieve stable and controllable pronking for a planar, underactuated hexapod model, based on the idea of &ldquo / template-based control&rdquo / , a controller structure based on the embedding of a simple dynamical template within a more complex anchor system. In this context, high-level control of the gait is regulated through speed and height commands to the SLIP template, while the embedding controller based on approximate inverse-dynamics and carefully designed passive robot morphology ensures the stability of the remaining degrees of freedom. We show through extensive simulation experiments that unlike existing open-loop alternatives, the resulting control structure provides stability, explicit maneuverability and significant robustness against sensor noise.
88

Integrated Design of Servo Mechatronic Systems for Driving Performance Improvement

Chen, Chin-yin 05 February 2009 (has links)
The servo mechatronic system design process usually covers two different engineering domains: structure design and system control. The relationship between these two domains is much closed. In order to reduce the disturbance caused by parameters in either one, the domain knowledge from those two different fields needs to be integrated. Thus, in order to reduce the disturbance caused by parameters in either one, the mechanical and controller design domains need to be integrated. Therefore, the integrated design method Design For Control (DFC), will be employed in this thesis. In this connect, it is not only applied to achieve minimal power consumption but also enhance structural performance and system response at same time. To investigate for the integrated design method, there are two common servo mechatronic systems: feed drive system and legged servo mechatronic system are used as the design platform. 1. Mechatronic Feed Drive System To investigate the method for integrated optimization, a mechatronic feed drive system of the machine tools is used as a design platform. The 3D software, Pro/Engineer is first used to build the 3D model to analyze and design structure parameters such as elastic deformation, nature frequency and component size, based on their effects and sensitivities to the structure. Additionally, in order to achieve system robust, Quantitative Feedback Theory (QFT), will be applied to determine proper control parameters for the controller. Therefore, overall physical properties of the machine tool will be obtained in the initial stage. Following this Design Then Control process, the iterative design process is following to enhance some of system performance. Finally, the technology design for control will be carried out to modify the structural and control parameters to achieve overall system performance. Hence, the corresponding productivity is expected to be greatly improved. 2. Legged Servo Mechatronic System The goal of this study is to develop a one-degree-of-freedom (DOF) legged servo mechatronic system with DFC. For this system, the kinematics and control dynamic analysis of legged servo mechatronic system have been solved by using four bar linkage with symmetrical coupler point, pantograph, and common position and velocity controller. In addition, in order to improvement system dynamic performance and reduce the control cost, the counterweight, that base on mass redistribution is employed to integrate structure and control into one design step for reduce shaking moment. Additionally, in order to improvement the system performance, the complete force balance is not only to take advantage of control cost, but also easy to control.
89

The ecology of Arctic cod (Boreogadus saida) and interactions with seabirds, seals, and whales in the Canadian Arctic

Matley, Jordan January 2012 (has links)
This thesis investigates the foraging of Arctic cod (Boreogadus saida) and its predators during the summer in the Canadian Arctic. Findings included the identification of Arctic cod, ringed seal (Pusa hispida), beluga (Delphinapterus leucas), and narwhal (Monodon monoceros) diet shifts in response to seasonal prey availability; calculation of isotopic diet-tissue discrimination factors for Arctic cod, ringed seals, and whales based on local tissue and stomach content sampling; and determination of predatory cues to optimize foraging, such as the presence of schools. Additionally, I quantified seabird feeding and interspecific interactions such kleptoparasitism and found that black-legged kittiwakes (Rissa tridactyla) and northern fulmars (Fulmarus glacialis) captured cod directly but lost many to parasitic jaegers (Stercorarius parasiticus) and glaucous gulls (Larus hyperboreus). Finally, I determined that schools of cod were important prey sources for northern fulmars, glaucous gulls, and whales however non-schooling cod were a significant source for black-legged kittiwakes and ringed seals.
90

The ecology of Arctic cod (Boreogadus saida) and interactions with seabirds, seals, and whales in the Canadian Arctic

Matley, Jordan January 2012 (has links)
This thesis investigates the foraging of Arctic cod (Boreogadus saida) and its predators during the summer in the Canadian Arctic. Findings included the identification of Arctic cod, ringed seal (Pusa hispida), beluga (Delphinapterus leucas), and narwhal (Monodon monoceros) diet shifts in response to seasonal prey availability; calculation of isotopic diet-tissue discrimination factors for Arctic cod, ringed seals, and whales based on local tissue and stomach content sampling; and determination of predatory cues to optimize foraging, such as the presence of schools. Additionally, I quantified seabird feeding and interspecific interactions such kleptoparasitism and found that black-legged kittiwakes (Rissa tridactyla) and northern fulmars (Fulmarus glacialis) captured cod directly but lost many to parasitic jaegers (Stercorarius parasiticus) and glaucous gulls (Larus hyperboreus). Finally, I determined that schools of cod were important prey sources for northern fulmars, glaucous gulls, and whales however non-schooling cod were a significant source for black-legged kittiwakes and ringed seals.

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