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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.
341

Vibration level characterization from a needle gun used on U.S. naval vessels

Dunn, Scott E. January 2006 (has links)
Thesis (M.A.)--University of South Florida, 2006. / Title from PDF of title page. Document formatted into pages; contains 42 pages. Includes bibliographical references.
342

Coordination of arm movements in healthy full term infants from the pre-reaching period to the onset of reaching

Lee, Hui-Min. January 2007 (has links)
Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: James C. Galloway, Dept. of Physical Therapy. Includes bibliographical references.
343

A state-based method to model and analyze the power consumption of embedded systems

Haulin, Lars January 2018 (has links)
In this work I have evaluated a method to model, measure and analyze the power consumption of embedded systems. The method combines current measurement with debug trace data telling which parts of the systems that are enabled. This makes it possible to compute the individual current consumption of the parts in the system from a single measurement point. The method allows an embedded systems engineer to determine the power consumption of individual parts in a system to either get an overview or to compare several revisions of hardware and/or software with each other. The method also captures the system dynamics of the power delivery route. This makes the model consumption behave more like the actual system around state transitions. The case study is focused on the Arm-based microcontroller CC2650 from Texas Instruments and uses the I-scope/I-jet probe from IAR Systems to measure current consumption and collect trace data.
344

HRC implementation in laboratory environment : Development of a HRC demonstrator

Boberg, Arvid January 2018 (has links)
Eurofins is one of the world's largest laboratories which, among other things, offer chemical and microbiological analyses in agriculture, food and environment. Several 100.000 tests of various foods are executed each year at Eurofins’ facility in Jönköping and the current processes include much repeated manual tasks which could cause ergonomic problems. The company therefore wants to investigate the possibilities of utilizing Human-Robot Collaboration (HRC) at their facility. Human-Robot Collaboration is a growing concept that has made a big impression in both robot development and Industry 4.0. A HRC approach allow humans and robots to share their workspaces and work side by side, without being separated by a protective fence which is common among traditional industrial robots. Human-Robot Collaboration is therefore believed to be able to optimize the workflows and relieve human workers from unergonomic tasks. The overall aim of the research project presented is to help the company to gain a better understanding about the existing HRC technologies. To achieve this goal, the state-of-the-art of HRC had to be investigated and the needs, possibilities and limitations of HRC applications had to be identified at Eurofins’ facility. Once these have been addressed, a demonstrator could be built which could be used for evaluating the applicability and suitability of HRC at Eurofins. The research project presented used the design science research process. The state-of-the-art of HRC was studied in a comprehensive literature review, reviewing sterile robots and mobile robotics as well. The presented literature review could identify possible research gaps in both HRC in laboratory environments and mobile solutions for HRC applications. These areas studied in the literature review formed together the basis of the prepared observations and interviews, used to generate the necessary data to develop the design science research artefact, the demonstrator. ABB's software for robotic simulation and offline programming, RobotStudio, were used in the development of the demonstrator, with the collaborative robot YuMi chosen for the HRC implementation. The demonstrator presented in the research project has been built, tested and refined in accordance to the design science research process. When the demonstrator could illustrate an applicable solution, it was evaluated for its performance and quality using a mixed methods approach. Limitations were identified in both the performance and quality of the demonstrator's illustrated HRC implementation, including adaptability and sterility constraints. The research project presented could conclude that a HRC application would be possible at a station which were of interest by the company, but would however not be recommended due to the identified constraints. Instead, the company were recommended to look for stations which are more standardized and have less hygienic requirements. By the end of the research project, additional knowledge was contributed to the company, including how HRC can affect today's working methods at Eurofins and in laboratory environments in general.
345

Determinação da coordenação de nado por meio da análise cinética e cinemática no estilo crawl

More, Felipe Collares January 2008 (has links)
A coordenação espaço-temporal dos movimentos dos braços de nadadores competitivos tem demonstrado ser um importante fator ligado a velocidade de nado e ao desempenho desses atletas. Os modelos básicos de coordenação comumente percebidos são: (1) captura - caracterizado pela existência de períodos sem propulsão entre a execução de cada braçada; (2) oposição - o movimento propulsivo de um braço inicia no exato instante em que o braço contra-lateral finaliza a fase propulsiva de seu movimento; (3) sobreposição - caracterizado por períodos com ação propulsiva simultânea dos dois braços. O objetivo deste estudo foi comparar os resultados da análise da simetria e da coordenação do nado crawl obtidos por meio dos métodos de cinemetria e dinamometria durante testes de nado livre e nado amarrado. Foram avaliados 13 nadadores federados voluntários do sexo masculino (idade: 19,4 ± 5,3 anos, estatura: 179,0 ± 5,2 cm, envergadura: 188,1 ± 6,0 cm, massa: 70,5 ± 8,7 kg, desempenho: 78,5 ± 4,2 % do recorde mundial de 50 m livres). Para obtenção das demais variáveis do estudo os nadadores foram submetidos à execução de dois protocolos distintos, realizados em piscina 25 m: (A) nado livre: 50 m nadados na máxima velocidade, com partida de dentro da piscina. Os atletas tiveram seu nado filmado (50 Hz) por duas câmeras colocadas dentro da água, uma em cada borda lateral da piscina, que foram deslocadas por operadores treinados a uma velocidade semelhante à velocidade de deslocamento do mesmo e (B) nado amarrado: nado estacionário em máxima intensidade com duração semelhante a do teste de nado livre. Os atletas tiveram a resultante das forças aplicadas por braçada medida por um transdutor de força fixado a borda da piscina onde era preso o cabo que estava ligado as suas cinturas e seus nados filmados (50 Hz) por duas câmeras posicionadas lateralmente a eles, sob a água. Um módulo eletrônico de sincronismo foi utilizado para disparar, simultaneamente, um sinal luminoso nas duas filmadoras e um pulso elétrico no sistema de aquisição dos dados oriundos do transdutor de força, possibilitando a posterior análise dos sinais oriundos de todos os aparatos utilizados para coleta dos dados. A partir da análise das imagens obtidas durante a execução de ambos os protocolos foram mensurados o índice de coordenação de nado (IdC), para ambos os braços (IdC1 e IdC2), em nado livre e nado amarrado e a freqüência média de braçadas (FB) na primeira e segunda metades do teste executado durante a aplicação de cada um dos protocolos. Os dados oriundos do transdutor de força permitiram a mensuração da diferença de tempo entre os picos de força aplicada por braçada (DFTA) para ambos os braços (DTFA1 e DTFA2). Os resultados mostraram um menor valor médio de IdC apresentado durante no nado livre (-3,59 ± 8,63 %) em relação ao nado amarrado (0,59 ± 7,92 %) indicando que, ao executarem o nado livre, os atletas adotam uma coordenação no modelo de captura e ao executarem o nado amarrado adotam uma coordenação em sobreposição, porém com valores que indicam uma possível coordenação no modelo de oposição. Diferentes valores de IdC1 (- 0,36 ± 7,44 %) e IdC2 (- 6,94 ± 8,52 %) foram encontrados em nado livre e nado amarrado (IdC1 = 3,76 ± 8,27 % e IdC2 = -2,54 ± 6,12 %). Os valores de FB apresentados pelos atletas na primeira metade de cada um dos testes foram significativamente mais elevados do que os valores de FB apresentados na segunda metade do respectivo teste (nado livre: [t(12) = 6,996; p < 0,001]; nado amarrado: [t(12) = 3,026; p = 0,011]). A comparação entre os valores de IdC1 e IdC2 adotados durante a execução de cada um dos protocolos mostrou que, durante o nado amarrado, todos os sujeitos apresentaram coordenação assimétrica enquanto durante o nado livre apenas três, dos 13 avaliados, foram considerados simétricos. A comparação entre os valores de DTFA1 e 2 demonstrou que apenas quatro sujeitos foram simétricos. A comparação dos valores da FB adotada pelos atletas mostrou que significativos maiores valores de FB foram apresentados durante o nado livre (FBiniL = 0,95 ± 0,08 ciclos.s-1, FBfinL = 0,88 ± 0,08 ciclos.s-1) em ralação ao nado amarrado (FBiniA = 0,79 ± 0,09 ciclos.s- 1, FBfinA = 0,76 ± 0,10 ciclos.s-1) na primeira e na segunda metades de ambos os testes. As comparações entre os valores de IdC apresentados durante nado livre e nado amarrado indicaram que apenas quatro, dos 13 sujeitos avaliados, mantiveram semelhantes valores para IdC1 e 2 em ambas as situações de nado. Apenas 3 dos sujeitos avaliados apresentaram valores significativos de correlação entre as variáveis IdC e DTFA. Com base nos achados deste estudo concluiu-se que: (1) durante os 50 m livres executados em máxima velocidade, os nadadores apresentaram, em média, uma coordenação no modelo de captura; (2) durante o nado amarrado os avaliados apresentaram uma coordenação em sobreposição, muito próxima da oposição; (3) o IdC e a FB medidas durante o nado livre foram diferentes das medidas durante o nado amarrado, indicando alterações da técnica; (4) a maioria dos nadadores avaliados manteve uma coordenação de nado considerada assimétrica em ambas as situações testadas e (5) a DTFA não se configurou como um parâmetro aceitável para determinação das simetrias e do modelo de coordenação de nado adotados durante o nado livre. Futuras investigações a cerca deste tema se fazem necessárias. / The spatial-temporal and coordinative structures of arms movements in competitive swimmers has been shown to be an important factor associated with swimming speed and performance of these athletes. The basic models of coordination commonly quoted are: (1) catch-up - describes a lag time between the propulsive forces of the two arms; (2) opposition - the propulsive phase of one arm begins when the other arm has just finished its propulsive phase; (3) superposition - describes an overlap of the propulsive phases of the two arms. The aim of this study was to compare the symmetry and the coordination analysis of front crawl swimming obtained through the kinematic and kinetic methods of free and tethered front crawl swimming. Thirteen male competitive swimmers volunteered this investigation (age: 19,4 ± 5,3 years, height: 179,0 ± 5,2 cm, arm span: 188,1 ± 6,0 cm, weight: 70,5 ± 8,7 kg, performance: 78,5 ± 4,2 % of world record at 50 m free style). Subjects underwent two different test protocols, both in a 25m indoor pool: (A) front crawl stroke: 50 m maximum swimming test, starting inside the pool. The athletes were recorded during all the test (50 Hz) by two underwater cameras, one on each lateral side of the pool, being transported by two experienced investigators at a speed equal to that of the swimmer, and (B) tethered swimming: tethered swimming at maximal intensity for the same period of the previous 50 m maximum test. Resultant force applied during each stroke was recorded by a force transductor attached on one side to the wall of the pool and on the other side to an inextensible cable that was attached to the swimmer's hips. The test was recorded during (50 Hz) by two underwater cameras, one on each lateral side of the swimmer. An electronic synchronization module was used to fire a LED light on both cameras and an electric pulse to the force acquisition recorder of the force transductor at the same time, this way allowing for correct interpretation of all data. From the images analysis of both protocols, we measured the index of coordination (IdC) for both arms (IdC1 and IdC2) during front crawl swimming and tethered swimming and the average stroke rate (SR) for the first and second half of both protocols. The data from the force transductor allowed for the determination of the time difference between the peak force applied per stroke (PFAS) for each arm (PFAS1 and PFAS2). The results show a smaller IdC mean for front-crawl stroke (-3,59 ± 8,63 %) compared to tethered swimming (0,59 ± 7,92 %), indicting that during front-crawl stroke the athletes prefer a catch-up coordination model, and during the tethered swimming condition they use a superposition coordination model, although some values suggest that some swimmers adopts opposition model during tethered swimming. Different values of IdC1 (-0,36 ± 7,44 %) and IdC2 (- 6,94 ± 8,52 %) were found for front-crawl and tethered swimming (IdC1 = 3,76 ± 8,27 % and IdC2 = -2,54 ± 6,12 %). Values of SR for the first half were higher than for the second half, irrespective of test condition (front-crawl: [t(12) = 6,996; p < 0,001]; tethered swimming: [t(12) = 3,026; p = 0,011]). Comparison between IdC1 and IdC2 used by athletes during the protocols revealed that during tethered swimming all subjects showed an asymmetric coordination, and during the front-crawl swimming only three subjects were considered symmetric. Comparison of SR values revealed significantly higher values for free swimming condition (SRiniF = 0,95 ± 0,08 stroke.s-1, SRfinF = 0,88 ± 0,08 stroke.s-1) compared to tethered swimming condition (SRiniT = 0,79 ± 0,09 stroke.s-1, SRfinT = 0,76 ± 0,10 stroke.s- 1), for both the first and second halves. The comparisons between IdC values of front-crawl and tethered swimming revealed that only four, of thirteen subjects evaluated, did have similar IdC1 and IdC2 values during both tests. Only three subjects showed a significant correlation between IdC and PFAS. Based on the findings of this study it was concluded that: (1) during 50 m front-crawl swimming maximum tests, the swimmers showed, on average, a catch-up coordination model; (2) during tethered swimming the subjects showed a superposition model of coordination, very close to the opposition one; (3) IdC and SR measured during front-crawl swimming were different from those measured during tethered swimming, indicating an alteration on the technique; (4) most of the swimmers tested showed an asymmetric coordination during both tests and (5) PFAS did not reveal as an acceptable parameter for determination of (as)symmetry and model of coordination during front-crawl swimming. Further investigations about this topic are required.
346

Vibração ocupacional em trator 4x2 tda em função da pressão interna dos pneus e da superfície de rolamento / Occupational vibration in tractor as affected by internal pressure of tires and rolling surface

Santos, Viviane Castro dos January 2016 (has links)
SANTOS, Viviane Castro dos. Vibração ocupacional em trator 4x2 tda em função da pressão interna dos pneus e da superfície de rolamento. 2016. 58 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2016. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-07-07T16:44:41Z No. of bitstreams: 1 2016-dis_vcsantos.pdf: 1527845 bytes, checksum: 5f4c4792b187b3208527de2f227a2055 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-07-07T16:46:37Z (GMT) No. of bitstreams: 1 2016-dis_vcsantos.pdf: 1527845 bytes, checksum: 5f4c4792b187b3208527de2f227a2055 (MD5) / Made available in DSpace on 2016-07-07T16:46:37Z (GMT). No. of bitstreams: 1 2016-dis_vcsantos.pdf: 1527845 bytes, checksum: 5f4c4792b187b3208527de2f227a2055 (MD5) Previous issue date: 2016 / The globalized world appreciates the market competition between big companies, having no difference at all when it comes to the agricultural environment, because in order to acquire more customers, the tractor manufacturers tend to invest in technology to increase the machine’s efficiency. These improvements are required and aim to increase production, reduce production costs and to adapt the machines to their users, in order to have more quality within the work. Several factors can influence the machine operation quality, especially noise, temperature and vibration which may directly affect welfare. The present study aimed to evaluate the whole operator body exposure to vibration as well as his hands and arms on a tractor on the following conditions, three different tire air pressure, two different forward speeds and two different shooting surfaces. The experiment was conducted in the experimental area of the Agricultural Machinery Accident Investigation Laboratory belonging to the Department of Agricultural Engineering of the Federal University of Ceará. The tractor utilized was a 4x2 tractor with auxiliary front wheel drive, Valtra brand, model BM 125i, year 2011 with a power of 91.9 kW (125 HP), maximum speed of 2,300 rotation per minute, equipped with radial tires. The experimental design was a completely randomized factorial 2 x 2 x 3 with two rolling surfaces (uncovered soil and soil covered with (Panicum maximum CV. Mombasa)), two forward speeds (4.3 km. h-1 and 6.4 km h-1), and three different tire air pressure (10, 14 and 18 lbs.pol-2) for the front tires and (12, 16 and 20 lbs.pol-2 ) for the rear tires. The experiment was conducted in accordance with the guidelines determined by the Brazilian operational hygiene standard number 09 and number 10 as well as the international ISO standard 5008, annex A. For the data evaluation, the statistical program ASSISTAT version 7.7 beta was utilized, checked for normality through the symmetry value and kurtosis analysis and consequently subjected to a variance analysis by F test, having the means compared by the Tukey test at 5% significance level. The vibration levels increased due to the increase in speed and the internal air pressure in tires and decreased with the use of the soil covering material. The best working condition was found in the following conditions, operations with soil covering material, at a speed of 4.3 km.h-1, using the tire air pressure at minimum (10 lbs.pol-2 on the front tires and 12 lbs.pol-2 on the rear tires). / O mundo globalizado preza pela concorrência no mercado de grandes empresas e isso não é diferente no meio agrícola, para adquirir cada vez mais clientes os fabricantes de trator tendem a investir em tecnologia para aumentar a eficiência de suas máquinas. Essas melhorias são necessárias nos tratores atuais e visam o aumento da produção, redução de custos de produção e adequação ao usuário para que o mesmo possa desempenhar o trabalho com qualidade. Vários fatores podem influenciar na qualidade de operação desempenhada pelo operador, principalmente fatores como, ruído, temperatura, vibração que interferem diretamente no seu bem estar. O objetivo do trabalho foi avaliar a exposição do operador às vibrações de corpo inteiro e mãos e braços em um trator agrícola em função da utilização de três pressões internas de ar nos pneus, duas velocidades de deslocamento e duas superfícies de rolamento. O experimento foi realizado na área experimental do Laboratório de Investigação de Acidentes com Máquinas Agrícolas, pertencente ao Departamento de Engenharia Agrícola da Universidade Federal do Ceará. O trator utilizado foi um trator 4x2 com tração dianteira auxiliar (TDA) da marca Valtra modelo BM 125i, ano 2011 com potência do motor de 91,9 kW (125 cv), rotação máxima de 2300 rpm, equipado com pneus radiais. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 x 2 x 3, sendo duas superfícies de rolamento dos pneus (solo solto e solo com (Panicum maximum cv. Mombaça) cobertura vegetal), duas velocidades de deslocamento (4,3 km.h-1 e 6,4 km.h-1), e três pressões internas nos pneus, sendo (10, 14 e 18 lb.pol-2) para os pneus dianteiros e (12, 16 e 20 lb.pol-2) para os pneus traseiros. O experimento foi realizado de acordo com as diretrizes determinadas pela NHO – 09, NHO – 10 e o anexo A da norma NBR ISO 5008. Para avaliação dos dados foi utilizado o programa estatístico ASSISTAT versão 7.7 beta, onde através dos valores de simetria e curtose foi verificada a normalidade e então submetidos à análise de variância pelo teste F, e quando significativas, as médias foram comparadas pelo teste de Tukey, a 5% de significância. Os níveis de vibrações aumentaram em função do aumento da velocidade e da pressão interna de ar nos pneus e diminuíram com o uso de material de cobertura no solo. A melhor condição de trabalho encontrada foi realizar as operações com material de cobertura sobre o solo, na velocidade de 4,3 km.h-1 na pressão interna de ar nos pneus mínima (10 lb.pol-2 nos rodados dianteiros e 12 lb.pol-2 nos rodados traseiros).
347

Desenvolvimento de um sistema neuro-fuzzi para análise de sinais mioelétricos do segmento mão-braço

Favieiro, Gabriela Winkler January 2012 (has links)
Pesquisas científicas no campo da engenharia de reabilitação estão proporcionando cada vez mais mecanismos que visam ajudar pessoas portadoras de alguma deficiência física a executar tarefas simples do dia-a-dia. Com isso em mente, esse trabalho tem a finalidade de desenvolver um sistema que utiliza sinais musculares e redes neuro-fuzzy para a caracterização de determinados movimentos de um braço humano, com o objetivo de possibilitar futuramente a integração em sistemas de reabilitação. Ensaios preliminares demonstraram que para a caracterização de movimentos simples realizados por um braço humano, o uso exclusivo de técnicas simples de processamento de sinal é suficiente, como a utilização do valor rms. No entanto, para a caracterização de movimentos complexos é necessário um processamento mais robusto do sinal. Para isso foi desenvolvido um sistema experimental que adquire, através de um eletromiógrafo (EMG) de 8 canais, o sinal mioelétrico com eletrodos de superfície posicionados em lugares estratégicos do braço. O sinal é adquirido utilizando como estímulo um modelo virtual que demonstra ao usuário os movimentos do segmento mão-braço que devem ser executados de forma aleatória. Finalmente, com o uso de uma rede neuro-fuzzy, que possibilita a distinção tanto de movimentos simples como de movimentos compostos, se adaptando a diferentes usuários, os movimentos executados foram caracterizados em 12 movimentos distintos, previamente definidos, com uma taxa de acerto médio de 65%. / The scientific researches in the field of rehabilitation engineering are increasingly providing mechanisms to help people with a disability to perform simple tasks of day-to-day. With that in mind, this work aims to develop an experimental robotic prosthesis in order to implement, in the same, a control system that uses muscle signals and neuro-fuzzy networks for characterization of certain movements of a human arm, in order to enable further integration in rehabilitation systems. Preliminary tests showed that for the characterization of simple movements performed by a human arm, the exclusive use of simple techniques of signal processing is sufficient, as the use of the rms value. However, for the characterization of complex movements is required a more robust signal processing. For this was developed an experimental system that acquires through an electromyography (EMG) of 8 channels, the myoelectric signal with surface electrodes positioned in strategic places of the arm. The acquired signal uses, as a stimulus, a virtual model that demonstrates the hand-arm segment movements to be executed by the user at random. Finally, through a neuro-fuzzy network, which enables the distinction of both simple and compound movements, self-adapting to different users, the movements performed were characterized in 12 distinct movements, previously defined, with an average accuracy of 65%.
348

Unconstrained humeral elevation exposure in occupational settings

Amasay, Tal, 1968- 09 1900 (has links)
xvi, 128 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / There were two primary goals of this work. The first goal was to investigate humeral and scapular kinematics in a simulated workplace environment. The second goal was to validate a triaxial accelerometer (Virtual Corset) for the collection of humeral elevation exposure data in an occupational setting. To achieve the first goal, healthy subjects were asked to perform constrained and functional humeral elevation motions. Differences were observed in scapular kinematics. In addition, the variability between constrained arm elevation and functional overhead tasks was found to be similar. Therefore, to compare scapular kinematics in an occupational group (dental hygienists) a functional work related task was determined to be more appropriate. The dental hygienists performed teeth instrumentation on simulated patients' with both big and average chest girth in a simulated work environment. Dental hygienist's humeral elevation and scapular upward rotation angles were found to be higher while working on the big chest girth manikin. These differences may increase dental hygienists susceptibility for musculoskeletal disorders. To achieve the second goal, an in-vitro comparison of angles measured with the Virtual Corset and an inclinometer was conducted under static conditions. Under dynamic conditions the Virtual Corset was compared to a potentiometer, in a pendulum setting. It was found that the Virtual Corset can accurately reconstruct elevation angles under static conditions, root mean square error less than 1[white square]. Under dynamic conditions, the error size was related to the angular velocity and acceleration, and the radius of rotation. To further investigate the Virtual Corset's ability to measure exposure parameters in-vivo the Virtual Corset was compare to a magnetic tracking device. To do so dental hygienists performed flossing tasks in a simulated work station. It was found that the Virtual Corset can be used to reconstruct elevation angles, with an acceptable angle error, and to identify exposure parameters in occupational settings similar to the one simulated in the present study. This dissertation includes unpublished co-authored material. / Adviser: Andrew R. Karduna
349

Aquisição, processamento de sinais mioelétricos e máquina de vetores de suporte para caracterização de movimentos do segmento mão-braço

Nilson, Clairê de Pauli January 2014 (has links)
As diversas áreas da Engenharia, em parceria com a ciência médica, têm contribuído de forma eficaz para o avanço do conhecimento e dos resultados em aplicações práticas na vida do deficiente físico. De forma geral, pesquisas com este foco têm permitido o desenvolvimento de dispositivos e recursos com o objetivo de oferecer novamente a mobilidade e a liberdade perdidas com a deficiência. Este trabalho tem a finalidade de desenvolver um sistema que utiliza Eletromiografia de Superfície e Máquina de Vetores de Suporte para a caracterização de determinados movimentos de um braço humano, possibilitando, futuramente, a integração em sistemas de reabilitação. Primeiramente os sinais mioelétricos são obtidos nos músculos do braço de voluntários através de eletrodos de superfície ligados a um eletromiógrafo. O sinal é adquirido, utilizando como padrão um modelo virtual que demonstra ao voluntário os movimentos do segmento mão-braço que devem ser imitados. Esses movimentos são executados e seus sinais mioelétricos adquiridos. Posteriormente, esses sinais são processados e características são extraídas. Em seguida, são alocadas algumas de suas características (RMS, média, variância, desvio padrão, skewness e kurtosis) na entrada da Máquina de Vetores de Suporte, que apresenta, como saída, o reconhecimento, ou não, do movimento previamente executado pelo voluntário. No final do processo, observou-se que aumentando o número de canais elevou-se a taxa de acerto dos movimentos e, com a retirada de determinada característica, houve decréscimo na taxa de acerto do sistema. Nestes casos, os 9 movimentos distintos atingiram uma taxa de acerto média de 83,2%, para dois canais, e 91,3%, para oito canais, e, em ambos sistemas de canais, com as seis características. / A wide range of engineering scopes, along with the knowledge from the medical science, has efficiently been contributing to further knowledge and results for practical applications in the life of the physically challenged. In general, such researches have allowed the development of devices and resources aimed at giving back the mobility and freedom lost with the deficiency. This paper intends to develop a system that uses Surface Electromyography and Support-Vector Machines (SVM) for the characterization of specific movements of a human arm enabling the future integration in rehabilitation systems. At first, myoelectric signals are obtained in the arm muscles of volunteers by means of surface electrodes attached to an Electromyography. The signal is acquired using a virtual model as pattern demonstrating to the volunteer the hand-arm movements which are to be replicated by the subject. As these movements are done, its respective myoelectric signals are acquired. Later on, these signals are processed and their characteristics extracted. Some of these features (such as RMS, standard deviation, variance, mean, kurtosis, skewness) will then be inserted in as input data in the Support- Vector Machine, which shows as an output a valid or null recognition of the movement earlier executed by the volunteer. At the end of the process, it was observed that increasing the number of channels increased by hit rate movements and, with the removal of certain characteristic, there was a decrease in the hit rate of the system. In these cases, nine distinct movements reached an average accuracy of 83.2% for two channels, and 91.3% for eight channels, and in both systems of channels, with six features.
350

Energy consumption and performance of HPC architecture for Exascale / Consumo de energia e desempenho de arquiteturas PAD para Exascale

Oliveira, Daniel Alfonso Gonçalves de January 2013 (has links)
Uma das principais preocupações para construir a próxima geração de sistemas PAD é o consumo de energia. Para quebrar a barreira de exascale a comunidade científica precisa investigar alternativas que possam lidar com o problema de consumo de energia. Sistemas PAD atuais não se preocupam com energia e já consomem GigaWatts. Requisitos de consumo de energia restringirão fortemente sistemas futuros. Nesse contexto processadores de alta potência abrem espaço para novas arquiteturas. Duas arquiteturas surgem no contexto de PAD. A primeira arquitetura são as unidades de processamento gráfico (GPU), GPUs possuem vários núcleos de processamento, suportando milhares de threads simultâneas, se adaptando bem a aplicações massivamente paralelas. Hoje alguns dos melhores sistemas PAD possuem GPUs que demonstram um alto desempenho por um baixo consumo de energia para várias aplicações paralelas. A segunda arquitetura são os processadores de baixo consumo, processadores ARM estão melhorando seu desempenho e mantendo o menor consumo de energia possível. Como exemplo desse ganho, projetos como Mont-Blanc apostam no uso de ARM para construir um sistema PAD energeticamente eficiente. Este trabalho visa verificar o potencial dessas arquiteturas emergentes. Avaliamos essas arquiteturas e comparamos com a arquitetura mais comum encontrada nos sistemas PAD atuais. O principal objetivo é analisar o consumo de energia e o desempenho dessas arquiteturas no contexto de sistemas PAD. Portanto, benchmarks heterogêneos foram executados em todas as arquiteturas. Os resultados mostram que a arquitetura de GPU foi a mais rápida e a melhor em termos de consumo de energia. GPU foi pelo menos 5 vezes mais rápida e consumiu 18 vezes menos energia considerando todos os benchmarks testados. Também observamos que processadores de alta potência foram mais rápidos e consumiram menos energia, para tarefas com uma carga de trabalho leve, do que comparado com processadores de baixo consumo. Entretanto, para tarefas com carga de trabalho leve processadores de baixo consumo apresentaram um consumo de energia melhor. Concluímos que sistemas heterogêneos combinando GPUs e processadores de baixo consumo podem ser uma solução interessante para alcançar um eficiência energética superior. Apesar de processadores de baixo consumo apresentarem um pior consumo de energia para cargas de trabalho pesadas. O consumo de energia extremamente baixo durante o processamento é inferior ao consumo ocioso das demais arquiteturas. Portanto, combinando processadores de baixo consumo para gerenciar GPUs pode resultar em uma eficiência energética superior a sistemas que combinam processadores de alta potência com GPUs. / One of the main concerns to build the new generation of High Performance Computing (HPC) systems is energy consumption. To break the exascale barrier, the scientific community needs to investigate alternatives that cope with energy consumption. Current HPC systems are power hungry and are already consuming Megawatts of energy. Future exascale systems will be strongly constrained by their energy consumption requirements. Therefore, general purpose high power processors could be replaced by new architectures in HPC design. Two architectures emerge in the HPC context. The first architecture uses Graphic Processing Units (GPU). GPUs have many processing cores, supporting simultaneous execution of thousands of threads, adapting well to massively parallel applications. Today, top ranked HPC systems feature many GPUs, which present high processing speed at low energy consumption budget with various parallel applications. The second architecture uses Low Power Processors, such as ARM processors. They are improving the performance, while still aiming to keep the power consumption as low as possible. As an example of this performance gain, projects like Mont-Blanc bet on ARM to build energy efficient HPC systems. This work aims to verify the potential of these emerging architectures. We evaluate these architectures and compare them to the current most common HPC architecture, high power processors such as Intel. The main goal is to analyze the energy consumption and performance of these architectures in the HPC context. Therefore, heterogeneous HPC benchmarks were executed in the architectures. The results show that the GPU architecture is the fastest and the best in terms of energy efficiency. GPUs were at least 5 times faster while consuming 18 times less energy for all tested benchmarks. We also observed that high power processors are faster than low power processors and consume less energy for heavy-weight workloads. However, for light-weight workloads, low power processors presented a better energy efficiency. We conclude that heterogeneous systems combining GPUs and low power processors can be an interesting solution to achieve greater energy efficiency, although low power processors presented a worse energy efficiency for HPC workloads. Their extremely low power consumption during the processing of an application is less than the idle power of the other architectures. Therefore, combining low power processors with GPUs could result in an overall energy efficiency greater than high power processors combined with GPUs.

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