Browsing by Issue Date, starting with "2013-02"
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- Transfemoral amputees' gait: principal component analysis of the knee momentsPublication . Soares, Denise; Castro, Marcelo; Mendes, Emília; Machado, LeandroThe purpose of this study was to compare the gait waveforms of the sagittal (KnSAG) and frontal (KnFRT) knee moments between both limbs of TF amputees with able-bodied subjects using PCA. the self-selected speed gait form 14 TF amputees and 20 able-bodied individuals was analyzed. The KnSAG and KnFRT of able-bodied participants, amputated limb and sound limb were calculated using the inverse dynamics approach. PCA was performed in moment waveforms. Considering KnSAG, both TF's lower limbs presented statistical differences compared to the able-bodied participants, while for KnFRT, only the sound limb showed statistical differences compared to the able-bodied subjects. PCA analysis seems to be a powerful tool to analyze gait parameters because it reduces the number of variables necessary to represent the whole gait waveform and it showed to be sensible to identify alterations in knee moment bahaviour.
- FPGAs to create a reconfigurable IEEE1451.0-compliant weblab infrastructurePublication . Costa, Ricardo J.; Alves, Gustavo R.; Zenha-Rela, MárioThe reconfiguration capability provided by Field Programmable Gate Arrays (FPGA) and the current limitations of weblab infrastructures, opened a new research window. This paper focus on describing the way weblabs can be reconfigured with different Instruments & Modules (I&M) required to conduct remote experiments, without changing the entire infrastructure. For this purpose, the paper emphasizes the advantage of using FPGAs to create reconfigurable weblab infrastructures using the IEEE1451.0 Std. as a basis to develop, access and bind embedded I&Ms to an IEEE1451.0-Module.
- Influência do posicionamento na qualidade dos movimentos de alcançar e transportar em indivíduos com esclerose múltiplaPublication . Pereira, Ana; Fernandes, Ângela; Sousa, Helena; Santos, RubimA Esclerose Múltipla (EM) é uma doença crónica e desmielinizante que causa uma degeneração difusa do Sistema Nervoso Central (SNC), levando gradualmente a défices neurológicos graves. A progressão da doença acarreta consigo uma multiplicidade de disfunções tanto físicas como psicológicas. Um dos pré-requisitos fundamentais para um melhor desempenho no alcançar e transportar objetos durante as diversas Atividades de Vida Diária (AVD) e Atividades de Vida Diária Instrumentais (AVDI), é a capacidade para manter um bom equilíbrio e uma postura adequada na posição de sentado na cadeira de rodas.
- A influência da imobilização do joelho na cinemática do membro contralateralPublication . Santos, M.; Lopes, Alfredo; Mesquita, I.; Crasto, CarlosA marcha é influenciada por um conjunto multifatorial resultante da interação ou do processo de organização própria de sistemas neurais e mecânicos. Estes sistemas estão envolvidos no controlo de movimentos rítmicos durante a locomoção originando padrões complexos e variáveis, permitindo um trabalho diferencial dos músculos dos membros inferiores em extensão e outro em flexão, refletindo-se numa maior dominância centrada no controlo do membro em flexão. Apesar da marcha ser extremamente robusta quer a alterações ambientais, quer a alterações físicas, desconhece-se até que ponto a indução da manutenção permanente em extensão do joelho pode influenciar os ângulos articulares do membro contralateral.
- Avaliação da perceção do risco por parte dos profissionais de educação em Jardins-de-Infância do concelho da MaiaPublication . Tavares, João; Azevedo, Rui; Vieira da Silva, ManuelaChildren safety in preschool age doesn’t depend only in their actions, but also of the risk perception of kindergarten education professionals which interact continuously with these children. The present study aims to evaluate the perceived risk of kindergarten teachers and auxiliary teaching staff, and the types of accidents occurred with the children of the kindergarten. A survey, based on the Portuguese legislation and reference documentation, was applied to a sample of 34 kindergarten teachers and 34 auxiliary teaching staff. This evaluation comprised the perception of risk related to different spaces and subjects of the kindergarten (structural conditions, playground, equipment and materials, electrical hazards and emergency organization). The results obtained revealed no statistical difference between risk perception of the two professionals groups, both occupational categories answered in general according to the requirements in the Portuguese legislation. The results obtained in the analysis the surveys allow, note that the playground is the place with the greatest potential for danger in kindergartens. Risk perception for both groups of educational professionals seems to be quite similar. In this matter, communication, as well as experience sharing seems to have greater influence. It was verified that recreational time, this being the place where most accidents occur in the kindergarten.
- Análise dinâmica do comportamento mecânico do ouvido médio com prótese totalPublication . Gentil, Fernanda; Marques, Marco; Garbe, Carolina; Santos, Carla; Parente, Marco; Martins, Pedro; Jorge, RenatoO presente trabalho tem como objetivo analisar e caracterizar o comportamento do ouvido médio quando uma prótese total substitui os elementos da cadeia ossicular de forma a solucionar problemas de surdez de transmissão. com base num modelo geométrico da cadeia ossicular saudável, a partir de imagens de TAC, foi criado um modelo onde uma prótese total foi incluída, assim como todos os objetos inerentes a esta adição. Foi assim efetuado o estudo dinâmico de vibrações forçadas para um modelo utilizando o método de elementos finitos. Foram obtidos os deslocamentos ao nível do umbo e da platina do estribo, para diferentes níveis de pressão sonora aplicada sobre a membrana timpânica, quando presente uma cartilagem na interface membrana-prótese de diferentes diâmetros e espessuras. Os resultados obtidos foram comparados com o modelo da cadeia tímpano-ossicular normal. A utilização deste modelo tem como objetivo conseguir definir a técnica que promove, da melhor maneira possível, a performance de uma prótese total no ouvido médio. Com este estudo pode-se afirmar que a reabilitação do ouvido médio com próstese do tipo TORP apresentará melhores resultados quando são utilizadas cartilagens de 4mm de diâmetro, com espessuras entre os 0.3mm e os 0.4mm.
- Efeitos de um programa de exercícios segundo pilates em indivíduos com asma controlada - controlo motor/função ventilatória [comunicação]Publication . Mesquita Montes, António; Carvalho, Paulo; Costa, Daniel; Moreira, Camilo; Monteiro, Pedro; Santos, RubimNuma situação normal, existem estratégias para coordenar a funções postural e ventilatória. Esta coordenação pode estar afetada durante o exercício físico ou na presença de patologia respiratória (asma), em que subsistem maiores necessidades ventilatórias. O método Pilates, que foca a relação entre o corpo e a disciplina mental, visa enfatizar a boa postura, o alinhamento corporal e a coordenação da ventilação com o movimento.
- Lower limb kinematics of transfemoral amputees gait: a principal component analysis approachesPublication . Soares, Denise; Castro, Marcelo; Mendes, Emília; Machado, LeandroThe purpose of this study was to compare the gait waveforms of the ankle, knee and hip in sagital plane kinematic variables between both limbs of transfemoral (TF) amputees and able-bodied subjects using principal component analysis (PCA). Fourteen TF amputees and 20 able-bodied subjects were enrolled in the study. The ankle, knee and hip sagittal plane kinematics were recorded for the able-bodied participants, for the amputed limb and sound limb during self-selected speed gait. The results showed that both TF's lower limbs presented statistical differences in all sudied joints when compared to the able-bodied participants, in different phases in the gait cycle. Also PCA analysis seems to be a powerful tool to descriminate gait parameters considering the whole waveform of the variables involved.
- Virtual Power Player Using Demand Response to Deal with Unexpected Low Wind Power GenerationPublication . Faria, Pedro; Vale, ZitaDemand response is assumed as an essential resource to fully achieve the smart grids operating benefits, namely in the context of competitive markets and of the increasing use of renewable-based energy sources. Some advantages of Demand Response (DR) programs and of smart grids can only be achieved through the implementation of Real Time Pricing (RTP). The integration of the expected increasing amounts of distributed energy resources, as well as new players, requires new approaches for the changing operation of power systems. The methodology proposed in this paper aims the minimization of the operation costs in a distribution network operated by a virtual power player that manages the available energy resources focusing on hour ahead re-scheduling. When facing lower wind power generation than expected from day ahead forecast, demand response is used in order to minimize the impacts of such wind availability change. In this way, consumers actively participate in regulation up and spinning reserve ancillary services through demand response programs. Real time pricing is also applied. The proposed model is especially useful when actual and day ahead wind forecast differ significantly. Its application is illustrated in this paper implementing the characteristics of a real resources conditions scenario in a 33 bus distribution network with 32 consumers and 66 distributed generators.
- Short-term Wind Forecasting to Support Virtual Power Player OperationPublication . Ramos, Sérgio; Soares, João; Pinto, Tiago; Vale, ZitaThis paper proposes a wind speed forecasting model that contributes to the development and implementation of adequate methodologies for Energy Resource Man-agement in a distribution power network, with intensive use of wind based power generation. The proposed fore-casting methodology aims to support the operation in the scope of the intraday resources scheduling model, name-ly with a time horizon of 10 minutes. A case study using a real database from the meteoro-logical station installed in the GECAD renewable energy lab was used. A new wind speed forecasting model has been implemented and it estimated accuracy was evalu-ated and compared with a previous developed forecast-ing model. Using as input attributes the information of the wind speed concerning the previous 3 hours enables to obtain results with high accuracy for the wind short-term forecasting.