Simulação numérica da convecção mista em cavidade preenchida com meio poroso heterogêneo e homogêneo

In this work is presented mixed convection heat transfer inside a lid-driven cavity heated from below and filled with heterogeneous and homogeneous porous medium. In the heterogeneous approach, the solid domain is represented by heat conductive equally spaced blocks; the fluid phase surrounds the blocks being limited by the cavity walls. The homogeneous or pore-continuum approach is characterized by the cavity porosity and permeability. Generalized mass, momentum and energy conservation equations are obtained in dimensionless form to represent both the continuum and the pore-continuum models. The numerical solution is obtained via the finite volume method. QUICK interpolation scheme is set for numerical treatment of the advection terms and SIMPLE algorithm is applied for pressure-velocity coupling. Aiming the laminar regime, the flow parameters are kept in the range of 102≤Re≤103 and 103≤Ra≤106 for both the heterogeneous and homogeneous approaches. In the tested configurations for the continuous model, 9, 16, 36, and 64 blocks are considered for each combination of Re and Ra being the microscopic porosity set as constant φ=0,64 . For the pore-continuum model the Darcy number (Da) is set according to the number of blocks in the heterogeneous cavity and the φ. Numerical results of the comparative study between the microscopic and macroscopic approaches are presented. As a result, average Nusselt number equations for the continuum and the pore continuum models as a function of Ra and Re are obtained.

Ambiente para aquisição e processamento de sinal eletromiográfico de superfície

In this work, a platform to the conditioning, digitizing, visualization and recording of the EMG signals was developed. After the acquisition, the analysis can be done by signal processing techniques. The platform consists of two modules witch acquire electromyography (EMG) signals by surface electrodes, limit the interest frequency band, filter the power grid interference and digitalize the signals by the analogue-to- digital converter of the modules microcontroller. Thereby, the data are sent to the computer by the USB interface by the HID specification, displayed in real-time in graphical form and stored in files. As processing resources was implemented the operations of signal absolute value, the determination of effective value (RMS), Fourier analysis, digital filter (IIR) and the adaptive filter. Platform initial tests were performed with signal of lower and upper limbs with the aim to compare the EMG signal laterality. The open platform is intended to educational activities and academic research, allowing the addition of other processing methods that the researcher want to evaluate or other required analysis.

Una solución asistida por computador a problemas educativos asociados con el tema método de trabajo en ingeniería industrial

Este documento contiene los aspectos más importantes de un trabajo de de un de investigación realizado en la Universidad del Valle con el propósito de ofrecer una alternativa de solución, apoyada en el computador, a un problema educativo detectado en el proceso de formación de ingenieros industriales, concretamente, en el curso Métodos de Trabajo.

Adaptação do paradigma orientado a notificações para desenvolvimento de sistemas fuzzy

This work proposes to adjust the Notification Oriented Paradigm (NOP) so that it provides support to fuzzy concepts. NOP is inspired by elements of imperative and declarative paradigms, seeking to solve some of the drawbacks of both. By decomposing an application into a network of smaller computational entities that are executed only when necessary, NOP eliminates the need to perform unnecessary computations and helps to achieve better logical-causal uncoupling, facilitating code reuse and application distribution over multiple processors or machines. In addition, NOP allows to express the logical-causal knowledge at a high level of abstraction, through rules in IF-THEN format. Fuzzy systems, in turn, perform logical inferences on causal knowledge bases (IF-THEN rules) that can deal with problems involving uncertainty. Since PON uses IF-THEN rules in an alternative way, reducing redundant evaluations and providing better decoupling, this research has been carried out to identify, propose and evaluate the necessary changes to be made on NOP allowing to be used in the development of fuzzy systems. After that, two fully usable materializations were created: a C++ framework, and a complete programming language (LingPONFuzzy) that provide support to fuzzy inference systems. From there study cases have been created and several tests cases were conducted, in order to validate the proposed solution. The test results have shown a significant reduction in the number of rules evaluated in comparison to a fuzzy system developed using conventional tools (frameworks), which could represent an improvement in performance of the applications.

Novas metodologias no ensino do inglês : o uso do computador no ensino do inglês

Académico - Licenciaturas

Classificação hierárquica com distribuições a posteriori: um estudo de simulação em padrões temporais de VIH

O objetivo deste trabalho é avaliar diferentes abordagens para identificação de grupos de pacientes VIH com padrões temporais de evolução da doença similares. Foi considerado um sistema de equações diferenciais ordinárias para caracterizar a comportamento ao longo do tempo de um paciente VIH sob tratamento antiretroviral - TAR de longo prazo, com 5 parâmetros estimados a partir de metodologia Bayesiana. As distribuições a posteriori foram usadas para quantificar distâncias (univariadas) entre pacientes, através do valor médio da distribuição a posteriori, e considerando a distância entre as distribuições a posteriori para cada parâmetro. O resultado do agrupamento hierárquico obtido pelas duas abordagens sugere que o uso de uma distância que considere a distribuição a posteriori é preferível. Trabalho futuro irá considerar distâncias multivariadas em vez de distâncias univariadas.

Simulação em uso dos pisos de madeira de Eucalyptus sp e Corymbia maculata

A caracterização anatômica, física, mecânica e química da madeira fornece informações importantes para sua melhor utilização. Contudo, para que madeiras se tornem boa opção para o mercado de pisos, adicionalmente é necessária a realização de ensaios que simulem suas reais condições em serviço. Esses ensaios simulam o pisoteio executado pelos sapatos de salto com pequenas áreas de pressão, o arraste e a queda de objetos, a resistência à abrasão da superfície e o atrito oferecido durante o deslocamento de pessoas que caminham sobre ele. Grande dificuldade da seleção de novas madeiras para pisos está na ausência de valores de referência físico-mecânicos. O presente trabalho visou a caracterizar as madeiras de Eucalyptus clöeziana F. Muell, de Eucalyptus microcorys F. Muell e de Corymbia maculata Hook, para as propriedades de densidade básica, retratibilidade, aplicação de carga rolante, de atrito estático e dinâmico, endentação causada por cargas aplicadas em pequenas áreas, impacto da esfera de aço cadente e resistência à abrasão. Foi observado que as madeiras estudadas podem ser utilizadas para a confecção de pisos, de acordo com seus resultados obtidos e por meio de comparações com resultados de literatura.

Estudo dos parâmetros dosimétricos de sementes de Iodo-125 desenvolvidas pelo IPEN-CNEN/SP utilizadas em braquiterapia por simulação computacional pelo método de Monte Carlo

Dissertação (Mestrado em Tecnologia Nuclear)

Implementação da rotina de unfolding para determinação de distribuição de tamanho de grãos esféricos via distribuição de interceptos lineares e de área de seção

Na unfolding method of linear intercept distributions and secction área distribution was implemented for structures with spherical grains. Although the unfolding routine depends on the grain shape, structures with spheroidal grains can also be treated by this routine. Grains of non-spheroidal shape can be treated only as approximation. A software was developed with two parts. The first part calculates the probability matrix. The second part uses this matrix and minimizes the chi-square. The results are presented with any number of size classes as required. The probability matrix was determined by means of the linear intercept and section area distributions created by computer simulation. Using curve fittings the probability matrix for spheres of any sizes could be determined. Two kinds of tests were carried out to prove the efficiency of the Technique. The theoretical tests represent ideal cases. The software was able to exactly find the proposed grain size distribution. In the second test, a structure was simulated in computer and images of its slices were used to produce the corresponding linear intercept the section area distributions. These distributions were then unfolded. This test simulates better reality. The results show deviations from the real size distribution. This deviations are caused by statistic fluctuation. The unfolding of the linear intercept distribution works perfectly, but the unfolding of section area distribution does not work due to a failure in the chi-square minimization. The minimization method uses a matrix inversion routine. The matrix generated by this procedure cannot be inverted. Other minimization method must be used

Simulação de escoamento sanguíneo em biomodelos digitais de patologias vasculares humanas

Os procedimentos cirúrgicos requeridos no tratamento de diversas patologias podem ser mais simples, baratos e eficientes com o uso das tecnologias de visualização e análise tridimensional de imagens médicas. Além de facilitar o diagnóstico, os modelos virtuais permitem ao cirurgião um planeamento detalhado e simulação de intervenções complexas. Estes modelos virtuais permitem a melhoria da capacidade de visualização, interação e otimização perante a situação clínica, possibilitando a identificação precoce de problemas. O objetivo deste trabalho é a análise do escoamento sanguíneo na aorta abdominal com aneurisma. A primeira etapa do trabalho consistiu na extração de dados anatómicos de um aneurisma, com recurso à imagiologia médica e à reconstrução do biomodelo digital Posteriormente, efetuou-se o estudo numérico do escoamento sanguíneo no biomodelo construído. Nas simulações numéricas, realizadas para escoamento laminar, a reologia do sangue foi descrita por três modelos: modelo Newtoniano, modelo de Carreau e Lei da Potência. Com a utilização destes três modelos foi possível averiguar o impacto das propriedades não-Newtonianas do sangue nos fluxos estudados. Adicionalmente, as simulações realizadas no biomodelo foram efetuadas num domínio geométrico similar ao biomodelo, mas mais simples. Esta análise foi efetuada de modo a averiguar se para as condições estudadas era possível recorrer a um modelo simplificado sem comprometer a análise do escoamento pretendido. Conclui-se que a utilização do modelo simplificado poderá ser vantajoso na análise de determinadas propriedades, uma vez que apresentou resultados compatíveis com os obtidos com o modelo real.

A simulação do real organizacional: O método dos casos como ponte entre o conhecimento tácito e o académico

O desenvolvimento da ciência organizacional tem sido marcado pelo desdobramento de modas e modelos nas mais diversas áreas. O presente artigo reflecte sobre o seu papel, particularmente, por via dos estudos de caso. Sendo as escolas de negócios e de gestão um dos actores importantes na difusão destes modismos, o método dos casos, enquanto estratégia pedagógica, é entendido aqui como um importante veículo de coordenação entre a investigação científica organizacional e a sua realidade. Contribui para a aproximação entre os vários intervenientes neste processo (professores, alunos, gestores, líderes e empresários). Advoga-se a sua importância por estabelecer uma ponte entre a academia e a o mundo organizacional, entre o conhecimento teórico dos académicos e o conhecimento tácito dos agentes empresariais.

SURI: Controlador MIDI por medio de un teclado de computador

El presente artículo narra las experiencias del desarrollo de Suri, un programa informático que permite enviar información MIDI a otros programas por medio del teclado del computador y combina las características lingüísticas de un editor de texto con elementos tecnológicos y musicales -- Del mismo modo, relata la forma en la que se conectó el desarrollo de este programa con la búsqueda de nuevas herramientas para la composición musical y describe sus diversas funciones y generalidades técnicas

Modos projetuais de simulação: uso de ferramentas de simulação térmica no processo projetual de arquitetura

This thesis aims to describe and demonstrate the developed concept to facilitate the use of thermal simulation tools during the building design process. Despite the impact of architectural elements on the performance of buildings, some influential decisions are frequently based solely on qualitative information. Even though such design support is adequate for most decisions, the designer will eventually have doubts concerning the performance of some design decisions. These situations will require some kind of additional knowledge to be properly approached. The concept of designerly ways of simulating focuses on the formulation and solution of design dilemmas, which are doubts about the design that cannot be fully understood nor solved without using quantitative information. The concept intends to combine the power of analysis from computer simulation tools with the capacity of synthesis from architects. Three types of simulation tools are considered: solar analysis, thermal/energy simulation and CFD. Design dilemmas are formulated and framed according to the architect s reflection process about performance aspects. Throughout the thesis, the problem is investigated in three fields: professional, technical and theoretical fields. This approach on distinct parts of the problem aimed to i) characterize different professional categories with regards to their design practice and use of tools, ii) investigate preceding researchers on the use of simulation tools and iii) draw analogies between the proposed concept, and some concepts developed or described in previous works about design theory. The proposed concept was tested in eight design dilemmas extracted from three case studies in the Netherlands. The three investigated processes are houses designed by Dutch architectural firms. Relevant information and criteria from each case study were obtained through interviews and conversations with the involved architects. The practical application, despite its success in the research context, allowed the identification of some applicability limitations of the concept, concerning the architects need to have technical knowledge and the actual evolution stage of simulation tools

Simulação computacional de medidas estereológicas em estruturas de metal duro (WC-Co)

This work focuses on the creation and applications of a dynamic simulation software in order to study the hard metal structure (WC-Co). The technological ground used to increase the GPU hardware capacity was Geforce 9600 GT along with the PhysX chip created to make games more realistic. The software simulates the three-dimensional carbide structure to the shape of a cubic box where tungsten carbide (WC) are modeled as triangular prisms and truncated triangular prisms. The program was proven effective regarding checking testes, ranging from calculations of parameter measures such as the capacity to increase the number of particles simulated dynamically. It was possible to make an investigation of both the mean parameters and distributions stereological parameters used to characterize the carbide structure through cutting plans. Grounded on the cutting plans concerning the analyzed structures, we have investigated the linear intercepts, the intercepts to the area, and the perimeter section of the intercepted grains as well as the binder phase to the structure by calculating the mean value and distribution of the free path. As literature shows almost consensually that the distribution of the linear intercepts is lognormal, this suggests that the grain distribution is also lognormal. Thus, a routine was developed regarding the program which made possible a more detailed research on this issue. We have observed that it is possible, under certain values for the parameters which define the shape and size of the Prismatic grain to find out the distribution to the linear intercepts that approach the lognormal shape. Regarding a number of developed simulations, we have observed that the distribution curves of the linear and area intercepts as well as the perimeter section are consistent with studies on static computer simulation to these parameters.