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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.
301

Designing tangible tabletop interactions to support the fitting process in modeling biological systems

Wu, Chih-Sung 13 November 2012 (has links)
This thesis aims to explore how to physically interact with computational models on an interactive tabletop display. The research began with the design and implementation of several prototype systems. The research of the prototype systems showed that tangible interactions on interactive tabletops have the potential to be more effective on some tasks than traditional interfaces that use screen displays, keyboards and mice. The prototype work shaped the research to focus on the effectiveness of adopting tangible interactions on interactive tabletops. To substantiate the thesis claims, this thesis develops an interactive tabletop application, Pathways, to support the fitting process in modeling biological systems. Pathways supports the concepts of Tangible User Interfaces (TUIs) and tabletop visualizations. It realizes real-time simulation of models and provides comparisons of simulation results with experimental data on the tabletop. It also visualizes the simulation of the model with animations. In addition to that, Pathways introduces a new visualization to help systems biologists quickly compare the simulation results. This thesis provides the quantitative and qualitative evaluation results of Pathways. The evidence showed that using tangible interactions to control numerical values is practical. The results also showed that in experimental conditions users achieved better fitting results and faster fitting results on Pathways than the control group, which used the systems biologists' current tools. The results further suggested that it is possible to recruit non-experts to perform the fitting tasks that are usually done by professional systems biologists.
302

Haptic-enabled teleoperation of hydraulic manipulators: theory and application

Zarei-nia, Kurosh 27 January 2012 (has links)
Hydraulic manipulators commonly interact with environments that are highly unstructured, and thus rely on the intelligence of human operators to provide proper commands. Typically, operators use visual information, directly or through cameras, to perform a task. Providing haptic or touch sensation about the task environment to the operator, enhances her/his ability to perform telemanipulation. The focus of this thesis is on haptic teleoperation of hydraulic manipulators. The application is directed at live transmission line maintenance tasks. In this thesis, both unilateral and bilateral haptic teleoperation of hydraulic manipulators are investigated. On the unilateral telemanipulation front, position error is shown to be an important issue in performing repetitive tasks. The most important sources of inaccuracy in position are sensors, robot controller performance, and the operator. To reduce the human operator’s errors, the concept of virtual fixtures is adopted in this research. It is shown that virtual fixtures can help operators perform routine tasks related to live line maintenance. Stability and telepresence are the main issues in reference to bilateral control. Three stable bilateral control schemes are designed for haptic teleoperation of hydraulic actuators considering nonlinear dynamics of hydraulic actuation, haptic device, and the operator. For each control scheme, stability of the entire control system is proven theoretically by constructing a proper Lyapunov function. Due to the discontinuity originating from a sign function in the control laws, the proposed control systems are non-smooth. Thus, the existence, continuation, and uniqueness of Filippov’s solution to the system are first proven for each control system. Next, the extensions of Lyapunov’s stability theory to non-smooth systems and LaSalle’s invariant set theorems are employed to prove the asymptotic stability of the control systems. In terms of telepresence, two types of haptic sensation are provided to the operator: (i) haptic based on the reflected interaction force, and (ii) haptic based on the position error. Performances of all proposed controllers are validated by experimental results on a hydraulic actuator controlled by a haptic device. It is shown that besides stability, the hydraulic actuator performs well in terms of position tracking while the haptic device provides telepresence for the operator.
303

Effects of haptic supplementation on postural stability in standing, perturbed standing and sitting in older adults

Albertsen, Inke 14 December 2012 (has links)
Le présent travail portait sur l'étude des effets de la supplémentation haptique sur la stabilité posturale debout et assise du sujet jeune et âgé. La question si les informations haptiques fournies par un support mobile améliorent la stabilité autant qu'un support fixe a peu été étudiée. Le présent travail visait à contribuer à une meilleure compréhension des mécanismes sous-jacents à l'effet stabilisateur potentiel d'un support type « canne mobile ». Les analyses portaient sur le centre de pression (COP). Les résultats des premières deux études confirment notre hypothèse générale sur l'effet de la supplémentation haptique indépendant de l'âge et de la mobilité du support. Si une résistance suffisante est fournie à l'opposé des oscillations du corps par le support les participants amélioraient leur stabilité. Dans la troisième étude, nous avons également manipulé des entrées visuelles et les résultats suggèrent qu'un manque de vision peut être compensé par la supplémentation. Dans la quatrième étude, nous avons également analysé la coordination inter-segmentaire. Les résultats suggèrent un meilleur contrôle postural avec la supplémentation alors qu'elle n'influence pas la coordination inter-segmentaire. La cinquième étude visait à déterminer si la supplémentation permettait d'améliorer la robustesse du système à des perturbations. Les résultats suggèrent que les sujets jeunes réduisent le temps de la première correction du COP avec la supplémentation alors que les sujets âgés corrigent leur COP plus tôt que les jeunes et ne bénéficient pas de cette dernière. Les résultats expérimentaux laissent envisager l'application du paradigme « canne mobile » à la locomotion. / This work was dedicated to the study of the effects of haptic supplementation on postural stability of young and old adults during standing and sitting tasks. The question of whether haptic information provided by a mobile support improves stability similar to a fixed support has been rarely studied. The present work aimed to contribute to a better understanding of the underlying mechanisms of the potential stabilizing effect of haptic information provided by a cane-like support. The analysis focused on the center of pressure (COP). The results of the first two studies confirmed our general hypothesis about the effect of haptic supplementation independent of age and the mobility of the support. If sufficient resistance is provided by the support against body sway participants improved their postural stability. In the third study, we also manipulated visual inputs and the results suggested that a lack of vision can be compensated due to supplementation. In the fourth study, we also analyzed the inter-segmental coordination. The results suggested a better postural control due to supplementation whereas it does not affect the inter-segmental coordination. The fifth study aimed to determine whether haptic supplementation improves the system's robustness to sudden perturbations. The results suggested that only young participants reduce the time to the first COP correction due to supplementation while elderly correct the COP earlier than young adults, even without additional haptic information, and therefore do not benefit from haptic supplementation. Overall, the experimental results open the way for the application of the “mobile-stick” experimental paradigm to locomotion.
304

Multi-Directional Slip Detection Between Artificial Fingers and a Grasped Object

January 2012 (has links)
abstract: Effective tactile sensing in prosthetic and robotic hands is crucial for improving the functionality of such hands and enhancing the user's experience. Thus, improving the range of tactile sensing capabilities is essential for developing versatile artificial hands. Multimodal tactile sensors called BioTacs, which include a hydrophone and a force electrode array, were used to understand how grip force, contact angle, object texture, and slip direction may be encoded in the sensor data. Findings show that slip induced under conditions of high contact angles and grip forces resulted in significant changes in both AC and DC pressure magnitude and rate of change in pressure. Slip induced under conditions of low contact angles and grip forces resulted in significant changes in the rate of change in electrode impedance. Slip in the distal direction of a precision grip caused significant changes in pressure magnitude and rate of change in pressure, while slip in the radial direction of the wrist caused significant changes in the rate of change in electrode impedance. A strong relationship was established between slip direction and the rate of change in ratios of electrode impedance for radial and ulnar slip relative to the wrist. Consequently, establishing multiple thresholds or establishing a multivariate model may be a useful method for detecting and characterizing slip. Detecting slip for low contact angles could be done by monitoring electrode data, while detecting slip for high contact angles could be done by monitoring pressure data. Predicting slip in the distal direction could be done by monitoring pressure data, while predicting slip in the radial and ulnar directions could be done by monitoring electrode data. / Dissertation/Thesis / M.S. Bioengineering 2012
305

Développement d'un simulateur haptique pour la cacaractérisation et la microinjection cellulaires / Haptic simulator for cell characterization and microinjection

Ladjal, Hamid 26 May 2010 (has links)
L'objectif fondamental de cette thèse est de développer et de mettre en oeuvre un outil interactif desimulation des techniques de micromanipulation biologiques de cellules. Au moyen de cet outil, l'opérateurpourra se former, s'entraîner et améliorer sa maîtrise en développant une gestuelle proche de celle exécutéeen réalité. La conception d'un tel environnement de simulation en temps-réel nécessite de trouver uncompromis entre le réalisme des modèles de comportement biomécanique utilisés, la précision et la stabilitédes algorithmes des méthodes de résolution et de rendu haptique utilisées ainsi que la vitesse de calcul. Lamodélisation mécanique retenue repose sur l'utilisation du modèle hyperélastique de St Venant-Kirchhoff etune formulation dynamique explicite éléments-finis du type masses-tenseurs. Le bien-fondé de cettemodélisation est vérifié sur des essais de microindentation par Microscopie à Force Atomique (AFM) decellules souches embryonnaires de souris et de microinjection d'ovocytes. Nous avons développé etimplémenté des modèles d'interaction en temps-réel qui s'articulent autour de la détection et la gestionrapide des collisions entre outil/cellule.La synthèse du rendu haptique fourni à l'opérateur est également proposée par l'intermédiaire d'un couplagevirtuel. Pour chaque application, nous avons justifié nos choix méthodologiques et Algorithmiques qui sontguidés par les contraintes de "réalisme+précision" "temps-réel". Les différents modèles proposés ont étéintégrés dans le simulateur SIMIC que nous avons développé pendant cette thèse. Ce dernier est dédié à lasimulation interactive pour l'aide à l'apprentissage du geste de microinjection et de nanoindentationcellulaire. / The fundamental objective of this thesis is to develop and implementing an interactive simulation techniquesfor micromanipulation biological cells. Using this tool, the operator can form, train and improve its control bydeveloping a gesture similar to that performed in reality. The design of such a simulation environment in realtime requires a compromise between the realism of biomechanical models used the accuracy and stability ofalgorithms and solution methods used haptic rendering and computational speed. Modeling Mechanicalrestraint involves the use of hyperelastic model of St Venant-Kirchhoff formulation and explicit dynamic finiteelement-type mass tensors. The validity of this model is tested on microindentation tests by Atomic ForceMicroscopy (AFM) of mouse embryonic stem cells and microinjection of oocytes. We have developed andimplemented models of real-time interaction that revolve around the detection and management of rapidcollisions between tool / cell.The synthesis of the haptic feedback provided to the operator is also available through a virtual coupling. Foreach application, we have justified our methodological choices and Algorithms that are guided by theconstraints of realism + precision "" real time ". The various proposed models have been integrated into thesimulator SIMIC that we developed during this thesis. This is dedicated to interactive simulation to supportlearning of gesture microinjection and cell nanoindentation.
306

Haptické deníky / Haptic diaries

ŠTĚCHOVÁ ŽÁKOVÁ, Marie January 2012 (has links)
These theses attempt to sketch the notion of touch in relation to art and everyday life. The first chapter deals closer with the sense of touch phenomena, introduce and characterize the touch communication, deals with creative types according to Viktor Lowenfeld, talks about haptic, art and touch. Later we introduce various types of diaries, psychological aspects of keep diaries and we also deal with diaries and taktilism relations. Third chapter has practical orientation and describe the meaning of haptic diaries. Last but not least it introduces particular haptic objects ? asamblages through the form of free associations. There are together 7 haptic objects created as a part of this theses.
307

A ancoragem funcional através do manejo de cão em tarefas de equilíbrio

Melo, Janaina Aparecida Carneiro de [UNESP] 29 July 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-29Bitstream added on 2014-06-13T20:09:59Z : No. of bitstreams: 1 melo_jac_me_rcla.pdf: 384734 bytes, checksum: 1b56a3e7e61d7b5af8dcb99fd242c506 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho é avaliar, ao longo de uma caminhada, a contribuição do sistema háptico durante a condução de um cão em condições de desafios ao sistema postural. Os desafios nas tarefas deste estudo incluem restrição da base de suporte para a marcha e privação visual. Esperamos que a sincronização entre condutor e cão se reflita em melhores níveis de desempenho no controle da marcha, especialmente na condição onde a visão é obstruída. Para este estudo foram recrutados 10 adultos jovens, com idade de média de 23,7 ± 4,32 anos e um cão treinado em obediência básica e na tarefa de condução em superfície restrita de apoio (traves de equilíbrio). As condições de tarefas foram: com e sem restrição da visão (CVSC e SVSC, respectivamente), e com e sem condução do cão (CVCC e SVCC, respectivamente). A primeira condição foi sempre a condição controle (olhos abertos sem condução do cão). Cada tentativa foi repetida três vezes. As tarefas foram filmadas por duas câmeras com o objetivo de avaliar a duração de cada ciclo do andar. Uma ANOVA three-way com medidas repetidas em todos os fatores (visão, tarefa e repetições) foi realizada para as variáveis: duração do ciclo de cada passada, média da fase relativa e o desvio da fase relativa, com medidas também repetitivas em todos os fatores para: visão, tarefa, pernas, e repetições. Testes a posteriori de Bonferroni foram calculados para comparações aos pares. Em relação à média da fase relativa as tarefas executadas com o cão foi significativamente superior àquelas sem o uso do cão. O pior relacionamento temporal foi mantido nas médias... / The purpose of this study was to assess the contribution of the haptic system during walking with a dog on challenging tasks to the postural system. The challenges included restriction to the base support (walking on a balance beam for both, the human and the dog), and visual occlusion (for the human only). We expected that the synchronization between the walking individual and the dog reflected in improved levels of performance in motion control, especially in conditions where vision is occluded. We recruited 10 young adults with average age of 23.7 ± 4.32 years and a dog with obedience training and conditioned to walk on a restricted area of support (balance beam). The task conditions were: with and without vision (CVSC and SVSC, respectively), and with and without conducting the dog (CVCC and SVCC, respectively). The first condition was always the control condition (eyes open without conducting the dog). Each trial was repeated three times. The tasks were videotaped with two cameras in order to process the duration of each stepping cycle. A three-way ANOVA with repeated measures on all factors (vision, and task repetitions) was performed for the variables: duration of each stepping cycle, relative phase and standard deviation of the relative phase, also with repeated measures on all of the factors: vision, task conditions, legs, and trials. The mean relative phase of the tasks performed with the dog was significantly closer to symmetry than those without the use of the dog. The worst temporal relationship was maintained during the condition SVSC (right leg = 0,477 ± 0,030, left leg = 0,544 ± 0,035). However... (Complete abstract click electronic access below)
308

Representações de brinquedos, relevos e descrição oral por crianças com deficiência visual

Ferroni, Giovana Mendes 25 August 2016 (has links)
Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-06-14T18:04:38Z No. of bitstreams: 1 TeseGMF.pdf: 9476298 bytes, checksum: f22d69fa07d6e52aff3ce9e78fe21273 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-06-26T17:37:13Z (GMT) No. of bitstreams: 1 TeseGMF.pdf: 9476298 bytes, checksum: f22d69fa07d6e52aff3ce9e78fe21273 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-06-26T17:37:21Z (GMT) No. of bitstreams: 1 TeseGMF.pdf: 9476298 bytes, checksum: f22d69fa07d6e52aff3ce9e78fe21273 (MD5) / Made available in DSpace on 2017-06-26T17:44:41Z (GMT). No. of bitstreams: 1 TeseGMF.pdf: 9476298 bytes, checksum: f22d69fa07d6e52aff3ce9e78fe21273 (MD5) Previous issue date: 2016-08-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / The research objective was to analyze the repertory of representations of means of transportation also called “vehicles” (Aircraft, bicycle, car, sail boat, train and helicopter) expressed in modeling clay, drawing and oral description of children with visual deficiency with the use of models like toys, or reliefs or the reading of the description of a mean of transportation made by the child itself. Participating in the study were two boys with congenital blindness (A and N) and two girls with low vision (G and K) with visual deficiency without any other deficiency associated, with ages between six and nine years old. The research was developed in two institutions frequented by the participants. One of them non-governmental and the other municipal, both specialized in the caring of people with visual deficiency, and localized in two midsize cities in the intern of São Paulo State, where the participants were receiving caring. A period of familiarization between researcher and participant preceded the data collect. The procedure of data collect was made in the following sequence of steps: Repertoire Survey, Intervention, Replication of the repertoire survey and creation of a mean of transportation. The Intervention consisted in presenting the participants the models: toy, relief and orally reading the oral description made by the child itself. In front of each model the children were requested to say the name of the object presented, play the model on a sequence of activities in which they used the modeling clay, pencil and paper to do a drawing and the oral production of the model which was worked on both previous conditions (modeling and drawing). During the confection of the representations the children answered questions about the characteristics and functions of the object presented. The data analysis guided itself by: 1- The component elements featured by the children and the characteristics attributed by them to the mean of transportation in the representations by modeling, drawing and oral description; 2- the type of model used during the intervention: toy, relief and reading of the oral description; 3- the creation of a vehicle using modeling clay, drawing and description. The results showed that, in the absence of models, in dealing with the component elements, the participants with low vision highlighted the external in their productions, for example, wheel, door, while the blind highlighted the internal, like, seat, steering wheel. However, when toys or reliefs were presented, the blind participants also highlighted in their productions the external elements. In the oral description, it was noted that all the children described above all the component elements and the aspects of the function played by them or the vehicles. However, in the oral descriptions of toy models or relief, they referred proportionally more times to the component elements. In reference to the used models in the intervention, the results indicated modifications in the drawing representations, modeling and oral description of the participants, if compared to the productions in the absence of the models. When there was the presentation of the toys to the blind participant, his productions in modeling clay were made on the same representation pattern of the toy, while that the drawing was made in a superior point of view, that is an object seen from the top. When there was the presentation of a relief model, the productions in drawing and modeling clay of the blind participant followed the flat point of view of the relief representation. When the reading of the oral description happened, the representations of the blind participant didn’t change. As to participant K, with low vision, the representations remained adopting the flat point of view for the three types of model. About the vehicle creation step, highlight itself that participant K, with low vision, created a new mean of transportation. The other participants (A, N and G) made means of transportation that had been worked during the intervention. The results empirically proved that the productions of the children with visual deficiency are different from the ones produced by children that can see, seen that they organize the world the notice by other sensorial channels other than the vision. This results were deep-set with the findings about the differences of production between children with visual deficiency. The representations of the blind children and of the ones with low vision considered different points of view; this results contribute to the discussion about the comparing between psychic children, children with visual deficiency/blindness and children with visual deficiency/low vision. It is believed that the results obtained in this work contribute to the discussions, even sparse, about the representations of children with visual deficiency. / O objetivo da pesquisa foi analisar o repertório de representações de meios de transporte também denominados “veículo” (avião, bicicleta, carro, barco a vela, trem e helicóptero) expressas em massa de modelar, desenho e descrição oral de crianças com deficiência visual com o emprego de modelos do tipo brinquedos ou relevos ou leitura da descrição de um meio de transporte feito pela própria criança. Participaram do estudo dois meninos com cegueira congênita (A e N) e duas meninas com baixa visão (G e K) com deficiência visual sem nenhuma outra deficiência associada, com idades entre seis e nove anos. A pesquisa foi desenvolvida em duas instituições frequentadas pelos participantes. Uma delas não governamental e a outra municipal, ambas especializadas no atendimento de pessoas com deficiência visual, e localizadas em duas cidades de médio porte do interior do estado de São Paulo, onde os participantes recebiam atendimentos. Um período de familiarização entre pesquisadora e participantes antecedeu a coleta de dados. O procedimento de coleta de dados foi realizado na seguinte sequência de etapas: Levantamento de Repertório, Intervenção, Replicação do Levantamento de Repertório e Criação de um meio de transporte. A Intervenção consistiu em apresentar aos participantes os modelos: brinquedo, relevo e ler oralmente a descrição oral feita pela própria criança. Diante de cada modelo as crianças foram solicitadas a dizer o nome do objeto representado, reproduzir o modelo em uma sequência de atividades nas quais usaram a massa de modelar, lápis e papel para fazer um desenho e a produção oral do modelo que foi trabalhado nas duas condições anteriores (modelagem e desenho). Durante a confecção das representações as crianças responderam perguntas sobre as características e funções do objeto representado. A análise dos dados guiou-se por: 1- os elementos componentes destacados pelas crianças e as características por elas atribuídas ao meio de transporte nas representações por modelagem, desenho e descrição oral; 2- o tipo de modelo utilizado durante a Intervenção: brinquedo, relevo e leitura da descrição oral; 3- a criação de um veículo utilizando massa de modelar, desenho e a descrição. Os resultados mostraram que, na ausência de modelos, em se tratando dos elementos componentes, os participantes com baixa visão destacaram em suas produções os externos, como por exemplo, roda, porta, enquanto que os cegos destacaram os internos, como, banco, volante. Entretanto, quando houve apresentação de brinquedo ou relevo, os participantes cegos também destacaram em suas produções os elementos externos. Na descrição oral, observou-se que todas as crianças descreveram sobretudo os elementos componentes e os aspectos da função desempenhados por eles ou pelos veículos. Entretanto, nas descrições orais de modelos brinquedo ou relevo elas se referiram proporcionalmente mais vezes aos elementos componentes. No que tange aos modelos utilizados na Intervenção, os resultados indicaram modificações nas representações em desenho, modelagem e descrição oral dos participantes, se comparadas às produções na ausência dos modelos. Quando houve apresentação de brinquedos para o participante cego, suas produções em massa de modelar foram confeccionadas no mesmo padrão de representação do brinquedo, enquanto que o desenho foi feito em um ponto de vista superior, isto é um objeto visto por cima. Quando havia apresentação de modelo em relevo, as produções em desenho e massa de modelar do participante cego seguiu o ponto de vista horizontal da representação em relevo. Quando houve leitura da descrição oral, as representações do participante cego não se modificaram. Quanto à participante K, com baixa visão, as representações permaneceram adotando o ponto de vista horizontal para os três tipos de modelo. A respeito da etapa de criação de um veículo, destaca-se que apenas a participante K, com baixa visão, criou um novo meio de transporte. Os demais participantes (A, N e G) confeccionaram meios de transporte que haviam sido trabalhados durante a Intervenção. Os resultados comprovaram empiricamente que as produções de crianças com deficiência visual são diferentes daquelas produzidas por crianças que enxergam, visto que elas organizam o mundo que percebem por meio de outros canais sensoriais que não a visão. Estes resultados foram aprofundados com os achados sobre as diferenças de produção entre as crianças com deficiência visual. As representações das crianças cegas e daquelas com baixa visão consideraram pontos de vistas diferentes; estes resultados contribuem para a discussão sobre a comparação entre crianças videntes, crianças com deficiência visual/cegueira e crianças com deficiência visual/baixa visão. Acredita-se que os resultados obtidos neste trabalho contribuam para as discussões, ainda que esparsas, sobre as a representações de crianças com deficiência visual.
309

Efeito do uso do sistema âncora no controle postural após a fadiga dos músculos flexores plantares em idosos / Effect of the use of the anchor system on postural control after flexor muscle fatigue plantar in the elderly

Andressa Busch Rocha Pereira 13 April 2017 (has links)
O controle postural é perturbado após a fadiga dos músculos flexores plantares. Por outro lado, o uso do sistema âncora reduz a oscilação postural. Entretanto, não se sabe se o uso dessa ferramenta seria capaz de compensar o aumento da oscilação corporal provocada pela fadiga muscular dos músculos flexores plantares. A informação háptica adicional fornecida pelo toque leve e o taping foi capaz de compensar o efeito perturbador da fadiga em adultos jovens. Porém, não se sabe como os idosos respondem a essa perturbação com o uso da informação háptica adicional. O objetivo desse estudo foi investigar se o uso do sistema âncora é capaz de compensar o aumento da oscilação corporal decorrente da fadiga dos músculos flexores plantares em adultos jovens e idosos. Os grupos de participantes foram testados descalços e com os olhos fechados em quatro condições na postura ereta: com e sem o sistema âncora, antes e depois do protocolo de fadiga. O sistema âncora consiste em dois cabos flexíveis com uma massa leve (125 g) fixada em uma das extremidades de cada cabo. Os participantes devem segurar um cabo em cada mão e manter o cabo esticado, sem retirar as cargas do solo. O protocolo de fadiga consistiu em realizar uma única série de flexão plantar bilateral do tornozelo repetidas vezes de forma constante e ininterrupta. Como esperado, o protocolo de fadiga aumentou a oscilação corporal nos dois grupos. Ambos os grupos se beneficiaram do uso das âncoras com a redução da oscilação corporal. Entretanto, esse efeito foi independente da fadiga. Concluímos que o sistema âncora contribuiu com a redução da oscilação corporal dos adultos jovens e idosos. Contudo, o sistema âncora não foi capaz de compensar o efeito perturbador postural em consequência da fadiga dos músculos flexores plantares. / The fatigue of the planta flexor muscles disturbs postural control. On the other hand, the use of the anchor system reduces postural sway. However, it is unknown whether the use of this tool would compensate for the increase of the body sway caused by muscle fatigue of the plantar flexor muscles. The additional haptic information provided by light touch and taping was able to compensate for the disturbing effect of fatigue in young adults. However, it is unknown how the old adults would respond to this disturbance with the use of additional haptic information. The purpose of this study was to investigate whether the use of the anchor system is able to compensate for the increase of the body sway due to fatigue of the plantar flexor muscles in young and old adults. The groups of participants were tested barefoot and with eyes closed in four conditions in upright posture: with and without the anchor system, before and after the fatigue protocol. The anchor system consists of two flexible cables with a light load (125 g) attached to one end of each cable. Participants should hold one cable in each hand and the keep the cable taut without removing the loads from the ground. The fatigue protocol consisted of performing a single series of bilateral plantar flexion of the ankles repeatedly and continuously and uninterrupted. As expected, the fatigue protocol increased body sway in both groups. Both groups benefited from the use of anchors with reduction of body sway. However, this effect was independent of fatigue. We conclude that the anchor system contributed to the reduction of body sway in young and old adults. However, the anchor system was not able to compensate for the disturbing effect in postural control created by fatigue of the plantar flexor muscles.
310

Virtual Reality as a Communication Process: User Perceptions and Experiences

Kalaiselvan, Kasthuri Brindha, Yan, Hanyu January 2017 (has links)
This thesis addresses the Virtual Reality (VR) as an efficient communication process, furtheremphasizes on the importance of Haptic Feedback in Virtual Reality applications. HapticFeedback plays a pivotal role in Virtual Reality simulations by enhancing users’ interactivityand immersion. Considering the human perceptions and experiences in line with technology isextremely significant for an effective Virtual Reality. The aim of this research is to study theperceptions and experiences of human participants about Virtual Reality applications,importance of Haptic Feedback, and to explore the advantages and limitations of suchapplications. The need to integrate Haptic Feedback in today’s Virtual Reality applications, andits advantages were emphasized. In order to acquire in-depth understanding of user’sperceptions and experiences about Virtual Reality as a communication process, a qualitativecase study was employed in this study with interpretive research approach and purposefulsampling. After interviewing the selective participants, the outcomes of the study would be toconsider Virtual Reality as an effective communication medium and to propose improvementplans for IKEA VR Experience with Haptic Feedback. Based on the outcomes of this study,organizations can strive towards providing richer Virtual Reality experience to their customersin the years to come.

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