26 resultados para Cryptography, Discrete Logarithm, Extension Fields, Karatsuba Multiplication, Normal Basis
em Instituto Politécnico do Porto, Portugal
Resumo:
Introdução: neste estudo foi avaliado um caso de lombociatalgia com hérnia discal lombar através de exame clínico confirmado por ressonância magnética. Foi efectuado um tratamento com terapia manual durante 4 semanas até à abolição dos sintomas e recuperação total da função. Objectivos: realizar um tratamento de terapia manual num paciente com lombociatalgia com hérnia discal lombar num período de 1 mês. Métodos: foi realizado um estudo num paciente de 40 anos do sexo masculino que apresentava um quadro de lombociatalgia com hérnia discal lombar. Para a avaliação foram utilizados testes palpatórios com movimento (teste de Mitchell lombar, teste de Gillet sacroilíaco); observação de assimetrias posturais; teste de mobilidade activa em pé; EVA para avaliação da dor; testes de compressão lombar na posição de sentado; testes de condução neurológica; testes neurodinâmicos. Os testes foram aplicados no início e final das 4 primeiras sessões de tratamento com terapia manual, com intervalo de uma semana e um follow-up realizado uma semana após a 4ª sessão. Resultados: após o tratamento de 4 sessões, verificou-se a ausência de postura antálgica. A dor diminuiu de 5/10 para 0/10 (EVA) nos movimentos de flexão, extensão, rotação esquerda e inclinação esquerda do segmento lombar, em pé, com amplitudes normais de mobilidade. A dor diminuiu 3/10 para 0/10 (EVA) no teste de compressão lombar sentado e de 6/10 para 0/10 (EVA) para o teste de compressão lombar sentado com inclinação esquerda. O teste de Mitchell lombar inicial (FRS L5; NSR lombar) ficou negativo assim como o teste de Gillet sacroilíaco; teste de SLR ; SLR + neck flection ; testes de condução de L5 que se encontrava positivo com hipostesia no dermátomo de L5 e grau 3+ de força nos dorsiflexores à esquerda ficou negativo para a hipostesia e grau 5 de força nos dorsiflexores. Conclusão: neste caso o conjunto de técnicas de terapia manual aplicadas juntamente com exercícios terapêuticos, concelhos posturais e de estilos de vida ajudaram o paciente a recuperar totalmente a função e ver abolida a dor.
Resumo:
Introdução: Os padrões de movimento podem sofrer alterações por atraso no timing de ativação e/ou modificações na sequência de recrutamento muscular, predispondo o indivíduo a disfunções, nomeadamente a dor lombo-pélvica. Objetivo: Investigar o timing e o padrão de ativação de músculos do core abdominal, durante o movimento de extensão da anca, do membro dominante, em indivíduos com e sem dor lombo- pélvica crónica inespecífica. Pretende-se, também, pesquisar a existência do padrão de ativação considerado “normal“ e verificar a relação entre o padrão de ativação e o tilt pélvico, em ambos os indivíduos. Métodos: Estudo transversal, com 64 estudantes universitários, divididos em dois grupos: 31 sem e 33 com dor lombo-pélvica. Através de eletromiografia de superfície foi recolhida a atividade muscular dos Eretores da Espinha ipsilateral e contralateral, Glúteo Máximo e Bicípite Femoral ipsilaterais. Foi analisado o timing de ativação muscular e as respetivas ordens de ativação. Adicionalmente foi medido o tilt pélvico. Resultados: O grupo com dor lombo-pélvica apresentou um atraso significativo no timing de ativação dos músculos Glúteo Máximo ipsilateral (t=-3,171;p=0,002) e Bicípite Femoral ipsilateral (t=-2,092;p=0,041), em comparação com o grupo sem dor. Verificou-se uma associação significativa entre as 5 ordens de ativação mais frequentes e a presença de dor lombo-pélvica (xf2=11,54;p=0,015). A ordem de ativação "normal" – Glúteo Máximo ipsilateral>Bicípite Femoral ipsilateral>Eretor da Espinha contralateral>Eretor da Espinha ipsilateral – não foi utilizada. Verificou-se que o Bicípite Femoral ipsilateral foi maioritariamente o primeiro a ativar-se e o Glúteo Máximo ipsilateral o último em ambos os grupos. Verificou-se um tilt pélvico significativamente superior nos indivíduos que ativam primeiro o Bicípite Femoral ipsilateral nos grupos com (U=51;p=0,001) e sem dor (U=41p=0,001). Conclusão: Os indivíduos com dor lombo-pélvica apresentaram um atraso no timing de ativação dos músculos do core abdominal. Os resultados parecem refutar a ordem de ativação "normal" que tem sido proposta. Não foi possível apoiar nem contestar a teoria de que um atraso na ativação do Glúteo Máximo está associado com dor lombo-pélvica.
Resumo:
Dissertação apresentada ao Instituto Politécnico do Porto para obtenção do Grau de Mestre em Gestão das Organizações, Ramo de Gestão de Empresas Orientada por Prof. Doutora Maria Alexandra Pacheco Ribeiro da Costa Esta dissertação inclui as críticas e sugestões feitas pelo júri.
Resumo:
The relation of automatic auditory discrimination, measured with MMN, with the type of stimuli has not been well established in the literature, despite its importance as an electrophysiological measure of central sound representation. In this study, MMN response was elicited by pure-tone and speech binaurally passive auditory oddball paradigm in a group of 8 normal young adult subjects at the same intensity level (75 dB SPL). The frequency difference in pure-tone oddball was 100 Hz (standard = 1 000 Hz; deviant = 1 100 Hz; same duration = 100 ms), in speech oddball (standard /ba/; deviant /pa/; same duration = 175 ms) the Portuguese phonemes are both plosive bi-labial in order to maintain a narrow frequency band. Differences were found across electrode location between speech and pure-tone stimuli. Larger MMN amplitude, duration and higher latency to speech were verified compared to pure-tone in Cz and Fz as well as significance differences in latency and amplitude between mastoids. Results suggest that speech may be processed differently than non-speech; also it may occur in a later stage due to overlapping processes since more neural resources are required to speech processing.
Integration of an automatic storage and retrieval system (ASRS) in a discrete-part automation system
Resumo:
This technical report describes the work carried out in a project within the ERASMUS programme. The objective of this project was the Integration of an Automatic Warehouse in a Discrete-Part Automation System. The discrete-part automation system located at the LASCRI (Critical Systems) laboratory at ISEP was extended with automatic storage and retrieval of the manufacturing parts, through the integration of an automatic warehouse and an automatic guided vehicle (AGV).
Resumo:
This paper reports on the analysis of tidal breathing patterns measured during noninvasive forced oscillation lung function tests in six individual groups. The three adult groups were healthy, with prediagnosed chronic obstructive pulmonary disease, and with prediagnosed kyphoscoliosis, respectively. The three children groups were healthy, with prediagnosed asthma, and with prediagnosed cystic fibrosis, respectively. The analysis is applied to the pressure–volume curves and the pseudophaseplane loop by means of the box-counting method, which gives a measure of the area within each loop. The objective was to verify if there exists a link between the area of the loops, power-law patterns, and alterations in the respiratory structure with disease. We obtained statistically significant variations between the data sets corresponding to the six groups of patients, showing also the existence of power-law patterns. Our findings support the idea that the respiratory system changes with disease in terms of airway geometry and tissue parameters, leading, in turn, to variations in the fractal dimension of the respiratory tree and its dynamics.
Resumo:
In the last twenty years genetic algorithms (GAs) were applied in a plethora of fields such as: control, system identification, robotics, planning and scheduling, image processing, and pattern and speech recognition (Bäck et al., 1997). In robotics the problems of trajectory planning, collision avoidance and manipulator structure design considering a single criteria has been solved using several techniques (Alander, 2003). Most engineering applications require the optimization of several criteria simultaneously. Often the problems are complex, include discrete and continuous variables and there is no prior knowledge about the search space. These kind of problems are very more complex, since they consider multiple design criteria simultaneously within the optimization procedure. This is known as a multi-criteria (or multiobjective) optimization, that has been addressed successfully through GAs (Deb, 2001). The overall aim of multi-criteria evolutionary algorithms is to achieve a set of non-dominated optimal solutions known as Pareto front. At the end of the optimization procedure, instead of a single optimal (or near optimal) solution, the decision maker can select a solution from the Pareto front. Some of the key issues in multi-criteria GAs are: i) the number of objectives, ii) to obtain a Pareto front as wide as possible and iii) to achieve a Pareto front uniformly spread. Indeed, multi-objective techniques using GAs have been increasing in relevance as a research area. In 1989, Goldberg suggested the use of a GA to solve multi-objective problems and since then other researchers have been developing new methods, such as the multi-objective genetic algorithm (MOGA) (Fonseca & Fleming, 1995), the non-dominated sorted genetic algorithm (NSGA) (Deb, 2001), and the niched Pareto genetic algorithm (NPGA) (Horn et al., 1994), among several other variants (Coello, 1998). In this work the trajectory planning problem considers: i) robots with 2 and 3 degrees of freedom (dof ), ii) the inclusion of obstacles in the workspace and iii) up to five criteria that are used to qualify the evolving trajectory, namely the: joint traveling distance, joint velocity, end effector / Cartesian distance, end effector / Cartesian velocity and energy involved. These criteria are used to minimize the joint and end effector traveled distance, trajectory ripple and energy required by the manipulator to reach at destination point. Bearing this ideas in mind, the paper addresses the planning of robot trajectories, meaning the development of an algorithm to find a continuous motion that takes the manipulator from a given starting configuration up to a desired end position without colliding with any obstacle in the workspace. The chapter is organized as follows. Section 2 describes the trajectory planning and several approaches proposed in the literature. Section 3 formulates the problem, namely the representation adopted to solve the trajectory planning and the objectives considered in the optimization. Section 4 studies the algorithm convergence. Section 5 studies a 2R manipulator (i.e., a robot with two rotational joints/links) when the optimization trajectory considers two and five objectives. Sections 6 and 7 show the results for the 3R redundant manipulator with five goals and for other complementary experiments are described, respectively. Finally, section 8 draws the main conclusions.
Resumo:
Remote experimentation laboratories are systems based on real equipment, allowing students to perform practical work through a computer connected to the internet. In engineering fields lab activities play a fundamental role. Distance learning has not demonstrated good results in engineering fields because traditional lab activities cannot be covered by this paradigm. These activities can be set for one or for a group of students who work from different locations. All these configurations lead to considering a flexible model that covers all possibilities (for an individual or a group). An inter-continental network of remote laboratories supported by both European and Latin American institutions of higher education has been formed. In this network context, a learning collaborative model for students working from different locations has been defined. The first considerations are presented.
Resumo:
Debugging electronic circuits is traditionally done with bench equipment directly connected to the circuit under debug. In the digital domain, the difficulties associated with the direct physical access to circuit nodes led to the inclusion of resources providing support to that activity, first at the printed circuit level, and then at the integrated circuit level. The experience acquired with those solutions led to the emergence of dedicated infrastructures for debugging cores at the system-on-chip level. However, all these developments had a small impact in the analog and mixed-signal domain, where debugging still depends, to a large extent, on direct physical access to circuit nodes. As a consequence, when analog and mixed-signal circuits are integrated as cores inside a system-on-chip, the difficulties associated with debugging increase, which cause the time-to-market and the prototype verification costs to also increase. The present work considers the IEEE1149.4 infrastructure as a means to support the debugging of mixed-signal circuits, namely to access the circuit nodes and also an embedded debug mechanism named mixed-signal condition detector, necessary for watch-/breakpoints and real-time analysis operations. One of the main advantages associated with the proposed solution is the seamless migration to the system-on-chip level, as the access is done through electronic means, thus easing debugging operations at different hierarchical levels.
Resumo:
“Drilling of polymeric matrix composites structures”
Resumo:
This study addresses the optimization of rational fraction approximations for the discrete-time calculation of fractional derivatives. The article starts by analyzing the standard techniques based on Taylor series and Padé expansions. In a second phase the paper re-evaluates the problem in an optimization perspective by tacking advantage of the flexibility of the genetic algorithms.
Resumo:
A genetic algorithm used to design radio-frequency binary-weighted differential switched capacitor arrays (RFDSCAs) is presented in this article. The algorithm provides a set of circuits all having the same maximum performance. This article also describes the design, implementation, and measurements results of a 0.25 lm BiCMOS 3-bit RFDSCA. The experimental results show that the circuit presents the expected performance up to 40 GHz. The similarity between the evolutionary solutions, circuit simulations, and measured results indicates that the genetic synthesis method is a very useful tool for designing optimum performance RFDSCAs.
Resumo:
Informal learning is becoming more and more important: Nowadays people learn more this way, through the Internet, than in schools or normal trainings. But they don’t get any certificateswhich attest this fact. So they can't show the employer or teacher etc. that they have learned something. TRAILER project aim is to solve this problem by developing a special tool for managing of all competences and skills acquired through informal learning experiences. Both from the perspective of the user and the perspective of an institution or a company. We’ll present the IT tool to show how people can make their informal learning outcomes visible. TRAILER helps users to gather all information about process and outcomes of their informal learning. Users can share this with friends, colleagues or their employees, teachers and so on. They can create an interactive e-portfolio which can be attached to their CV, cover letter or Knowledge Management system etc. After the presentation of the tool we will discuss possible areas and fields to use this tool. Also we would like to discuss all possible use of the tool by the participants and another needs in this area. Moreover we want to discuss other problems in informal learning process, ways to solve the problems and discuss other ideas of different IT tools which could help in informal learning process. During the discussion we’ll use an interactive respond system which can be used on mobile devices: it makes possible for participants to share their opinions individually before knowing another persons' opinion.
Resumo:
The paper presents a RFDSCA automated synthesis procedure. This algorithm determines several RFDSCA circuits from the top-level system specifications all with the same maximum performance. The genetic synthesis tool optimizes a fitness function proportional to the RFDSCA quality factor and uses the epsiv-concept and maximin sorting scheme to achieve a set of solutions well distributed along a non-dominated front. To confirm the results of the algorithm, three RFDSCAs were simulated in SpectreRF and one of them was implemented and tested. The design used a 0.25 mum BiCMOS process. All the results (synthesized, simulated and measured) are very close, which indicate that the genetic synthesis method is a very useful tool to design optimum performance RFDSCAs.
Resumo:
A área da simulação computacional teve um rápido crescimento desde o seu apareciment, sendo actualmente uma das ciências de gestão e de investigação operacional mais utilizadas. O seu princípio baseia-se na replicação da operação de processos ou sistemas ao longo de períodos de tempo, tornando-se assim uma metodologia indispensável para a resolução de variados problemas do mundo real, independentemente da sua complexidade. Das inúmeras áreas de aplicação, nos mais diversos campos, a que mais se destaca é a utilização em sistemas de produção, onde o leque de aplicações disponível é muito vasto. A sua aplicação tem vindo a ser utilizada para solucionar problemas em sistemas de produção, uma vez que permite às empresas ajustar e planear de uma maneira rápida, eficaz e ponderada as suas operações e os seus sistemas, permitindo assim uma rápida adaptação das mesmas às constantes mudanças das necessidades da economia global. As aplicações e packages de simulação têm seguindo as tendências tecnológicas pelo que é notório o recurso a tecnologias orientadas a objectos para o desenvolvimento das mesmas. Este estudo baseou-se, numa primeira fase, na recolha de informação de suporte aos conceitos de modelação e simulação, bem como a respectiva aplicação a sistemas de produção em tempo real. Posteriormente centralizou-se no desenvolvimento de um protótipo de uma aplicação de simulação de ambientes de fabrico em tempo real. O desenvolvimento desta ferramenta teve em vista eventuais fins pedagógicos e uma utilização a nível académico, sendo esta capaz de simular um modelo de um sistema de produção, estando também dotada de animação. Sem deixar de parte a possibilidade de integração de outros módulos ou, até mesmo, em outras plataformas, houve ainda a preocupação acrescida de que a sua implementação recorresse a metodologias de desenvolvimento orientadas a objectos.