Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.

Submitted by Ana Carolina de Lima Sarmento (carol_sarmento@hotmail.com) on 2018-06-26T16:48:22Z No. of bitstreams: 1 VERSÃO FINAL DISSERTAÇÃO ANA SARMENTO.pdf: 4193853 bytes, checksum: 411f0e8e77081749a480a2df69ae5228 (MD5) / Approved for entry into archive by Lêda Costa (lmrcosta@ufba.br) on 2018-06-26T17:51:53Z (GMT) No. of bitstreams: 1 VERSÃO FINAL DISSERTAÇÃO ANA SARMENTO.pdf: 4193853 bytes, checksum: 411f0e8e77081749a480a2df69ae5228 (MD5) / Made available in DSpace on 2018-06-26T17:51:53Z (GMT). No. of bitstreams: 1 VERSÃO FINAL DISSERTAÇÃO ANA SARMENTO.pdf: 4193853 bytes, checksum: 411f0e8e77081749a480a2df69ae5228 (MD5) / FUNDAÇÃO DE AMPARO A PESQUISA DO ESTADO DA BAHIA - FAPESB / Os interiores revelam não só um espaço físico, mas também um ambiente psicológico de valores, gestos e significados. Partindo da problemática “Como diminuir os impactos ambientais em projetos de interiores?”, no presente trabalho, apresenta-se como objetivo geral proporcionar aos designers de interiores uma metodologia de projeto que permita uma antecipação dos impactos ambientais, partindo-se da análise do modelo IDSRS (Indicadores de Design, Sustentabilidade e Responsabilidade Social), desenvolvido por Souza (2007) no contexto do design de produto, que foi adaptado para uso no design de interiores. Com isso, viabiliza a associação desse percurso projetivo e avaliativo dos impactos, pelos atores envolvidos a uma experiência multissensorial voltada ao sentir, perceber, notar e compreender, que se constituem em elementos-chave para a construção de uma percepção ambiental formativa para o processo de tomada de decisões e para a educação ambiental. Esta pesquisa configura-se de natureza exploratória e qualitativa, pois busca familiarizar-se com o tema, reunindo informações sobre as relações existentes entre sustentabilidade e design de interiores. Integram os procedimentos metodológicos da pesquisa: coleta e análise sistemática de dados, levantamento bibliográfico, visitas em loco, estudo de caso descritivo e consolidação do modelo adaptado por meio da teoria fundamentada em dados. O estudo de caso tomou como base a construção de uma residência localizada em Itacimirim – BA, onde foram acompanhadas todas as etapas da construção, desde a concepção do projeto até a sua implementação/execução. O estudo tem como principal contribuição refletir sobre todas as etapas que envolvem o projeto de interiores, adequando esses ambientes aos parâmetros da sustentabilidade. Pretende-se, a partir da utilização do modelo IDSRS adaptado, contribuir com a antecipação dos impactos ambientais e com um ambiente técnico mais definido, estabelecendo claramente o papel de todos os agentes envolvidos. / The interiors reveal not only a physical space, but also a psychological environment of values, gestures and meanings. Starting from the problematic: How to reduce the environmental impacts in interior projects? The objective of this work is to provide interior designers with a design methodology that allows an anticipation of environmental impacts through a model of sustainability indicators. The IDSRS model (Indicators of Design, Sustainability and Social Responsibility), developed by Souza (2007) in the context of product design, was adapted for use in interior design. As specific objectives, we identified the bibliography referring to the practice of sustainability with a cut-out for interior design, described the IDSRS model, adapted to interior design and demonstrated its use in a case study. With this, it makes possible the association of this projective and evaluative course of the impacts, by the involved actors to a multisensorial experience focused on the perception, perceiving, noting and understanding, that are constituted in key elements for the construction of a formative environmental perception for the process of decision-making and environmental education. This research is of an exploratory and qualitative nature, as it seeks to familiarize itself with the theme, gathering information on the relationship between sustainability and interior design. They integrate the methodological procedures of the research: analysis and systematic analysis of data, bibliographic survey, site visits, descriptive case study and a consolidation of the model adapted through the theory based on data. The case study was based on the construction of a residence located in Itacimirim - BA where we follow all stages of construction, from project design to implementation / execution. The main contribution of the study is to reflect on all the steps involved in interior design, adapting these environments to the parameters of sustainability. It intends from its use to contribute with the anticipation of the environmental impacts and with a more defined technical environment, clearly establishing the role of all the agents involved.

Este trabalho apresenta uma metodologia de projeto de atuadores eletromagnéticos lineares inovadora para aplicação em sistemas de suspensão semiativa e ativa. A metodologia, apresentada na forma de fluxograma, define critérios para determinar os requisitos de força e curso que um atuador deve desenvolver considerando um sistema mecânico vibratório com um grau de liberdade com excitação harmônica de base quando o método de controle skyhook é aplicado. Um atuador eletromagnético linear de bobina móvel com duplo arranjo de quase-Halbach que apresenta elevada densidade de força, reduzida massa móvel, ausência de força de relutância e baixa ondulação de força é definido como estudo de caso. Um modelo numérico parametrizado em elementos finitos do comportamento eletromagnético de um passo polar do dispositivo é criado e analisado, considerando restrições dimensionais, com os objetivos de projeto definidos como: elevada densidade de força e reduzida ondulação de força com acionamento brushless CA. Com base no modelo de um passo polar do dispositivo, define-se o volume ativo que o mesmo deve apresentar e, a partir deste, todas as dimensões são definidas de forma a atender os requisitos de projeto. Uma vez definidas as dimensões do atuador com base no modelo eletromagnético, realiza-se a modelagem térmica numérica que permite avaliar qual a máxima densidade de corrente elétrica aplicável de forma que a temperatura, estipulada como máxima, nos enrolamentos não seja excedida. Ainda, a distribuição térmica permite determinar a temperatura de operação dos ímãs permanentes que têm curva de operação dependente da temperatura. A partir dos resultados da simulação térmica e do modelo eletromagnético para um passo polar, realizou-se o acoplamento eletromagnético-térmico por meio da correção das propriedades dos ímãs permanentes e aplicando uma densidade de corrente eficaz dependente das dimensões do modelo parametrizado. O modelo acoplado é simulado e analisado, de modo que as dimensões finais do atuador podem ser obtidas atendendo aos mesmos objetivos de projeto previamente mencionados, respeitando os limites de operação térmica. Adicionalmente, são apresentados modelos analíticos do comportamento eletromagnético e térmico do atuador que podem servir de base para implementação da metodologia proposta, se esta for baseada em modelos analíticos, e podem futuramente ser empregados para a aplicação de otimização matemática do dispositivo. Por fim, um protótipo do dispositivo é construído de forma a validar a metodologia proposta. Com este protótipo são realizados ensaios de densidade de fluxo magnético no entreferro, tensão induzida a vazio, força estática e ensaio dinâmicos com o dispositivo instalado em uma bancada de testes de vibrações controladas desenvolvida durante o projeto. Os resultados mostram a eficácia da metodologia proposta, uma vez que os resultados experimentais mostraram boa concordância com os resultados esperados. / This work presents an innovative linear electromagnetic actuator design methodology for application in semi-active and active suspension systems. The methodology, synthesized in a flowchart, sets criteria to determine requirements such as axial force and stroke that an actuator should develop considering a vibration system with one degree of freedom with harmonic base excitation when the skyhook control method is applied. A linear moving-coil electromagnetic actuator with dual quasi-Halbach arrays of permanent magnets that presents high force density, low moving-mass, no reluctance force and low force ripple is defined as a case study. A finite element numerical parameterized model that describes the electromagnetic behavior of one pole pitch of the device is created and analyzed, considering dimensional constraints, with the design objectives defined as: high force density and low ripple of force with brushless AC drive. Based on the model of one pole pitch of the device the active volume and all dimensions are defined in order to meet the design requirements. Once the actuator dimensions are defined, based on the electromagnetic model, a numerical thermal model was constructed, which allows to evaluate the maximum applicable electric current density so that the maximum temperature at the windings is not exceeded. Furthermore, the thermal distribution gives the operating temperature of the permanent magnets, which present performance highly dependent on temperature. With the results of the thermal simulation, the electromagnetic-thermal coupling is performed by correcting permanent magnet properties and by applying a parametric-dependent effective current density. The coupled model is simulated and analyzed so that the final dimensions of the actuator can be obtained with the same design objectives previously mentioned, while respecting thermal operating limits. In addition, the work presents analytical models of the electromagnetic and thermal behavior of the actuator that can be the basis for implementation of the proposed methodology, if it is based on analytical models, and can further be used for the application of mathematical optimization of the device. Finally, a prototype was built to validate the proposed method. Measurements were carried out to assess magnetic flux density in the air gap, open-circuit induced voltage, static force and dynamic tests with the device installed in a test bench that was developed during this work. The results show the effectiveness of the proposed method since experimental results have shown good agreement with the expected results.

Os sistemas dinamicamente reconfiguráveis (SDRs) são uma alternativa para o desenvolvimento de sistemas sobre silício baseados em circuitos programáveis (SoPC), cujo principal beneficio é o bom aproveitamento da área do dispositivo. Sendo neles implementados circuitos que representam as tarefas que devem operar numa etapa específica do tempo de operação do sistema, permitem um menor consumo de área e de energia, parâmetros importantes nos sistemas portáveis. Isto tem gerado muito interesse no que se refere às metodologias de projeto utilizando FPGAs (Field Programmable Gate Arrays) dinamicamente reconfiguráveis (DRFPGAs) e à definição de um meio de comunicação estruturado para tratar da transferência de dados entre as partes reconfiguráveis e as fixas, mas estas tarefas, assim como a concretização de sua comunicação, seguem sendo ainda essencialmente manuais, devido à falta de metodologias de projeto e ferramentas de CAD que simplifiquem o projeto de SDRs. Este trabalho foca uma das limitações mais efetivas para a adoção da reconfiguração dinâmica: a falta de ferramentas de CAD que suportem o projeto de SDRs, inclusive os baseados em redes intra-chip (NoCs), em particular, no posicionamento dos módulos. Neste trabalho, uma arquitetura para SDRs baseado em NoCs é proposta e um algoritmo de posicionamento dos módulos de um SDR baseado em aspectos reais da família do DRFPGAs é desenvolvido, dentro de uma ferramenta denominada DynoPlace. Desenvolveu-se também um modelo de validação e simulação de SDRs, em tempo de operação, utilizando-se a técnica de chaveamento dinâmico de circuitos. Para o estudo do caso, de validação da arquitetura e metodologia, propõe-se uma aplicação teste baseada em computação de operações aritméticas. A metodologia de simulação permite determinar o tempo da reconfiguração e verificar o comportamento do SDR no momento da reconfiguração. A ferramenta DynoPlace permite gerar os arquivos de restrição de usuário (UCF) de posicionamento dos módulos do SDR no DRFPGA Virtex-4LX25. Este contém informações do posicionamento dos módulos do sistema, dos dispositivos usados para as entradas e saídas do sistema além do posicionamento dos bus-macros. Com os arquivos gerados pela metodologia e ferramenta DynoPlace, pode-se executar com sucesso os scripts da metodologia Early Access da Xilinx para gerar o SDR de forma automática. / Dynamically Reconfigurable Systems (DRSs) are an alternative for developing Systems on a Programmable Chip (SoPC), being the efficient use of device\'s area one of its main advantages. Circuits implemented as DRSs represent tasks which must be active in specific times into the system operation, allowing area and energy saving, which is an important goal for portable systems. This has generated interests on the design methodology using Dynamically Reconfigurable Field Programmable Gate Arrays (DRFPGAs) and on the definition of communication systems for handling data transfer between static and reconfigurable partitions. However, these tasks, as well as the communication structure, are still carried out manually due to lack of design methodologies and CAD tools applied to DRSs design. This work focuses on the one of main drawbacks to the adoption of dynamic reconfiguration methods: the absence of CAD tools which support DRS designs, specifically, in the module positioning task, included, for those based on Network-on-Chip (NoCs). In this work, an architecture for DRSs based on NoCs is presented and an algorithm for module positioning is developed in a tool called DynoPlace as well, based on real specifications of DRFPGAs families. It is also developed a run-time simulation and validation model for DRSs, through a dynamic circuit switching technique. For the validation of architecture and methodology study case, an application test based on arithmetic operations has been proposed. The simulations methodology allows to determine the reconfiguration time and verify the DRS behavior at the moment of reconfiguration. The DynoPlace tool allows to generate User Constraint File (UCF) of DRS\'s modules positioning for the DRFPGA Virtex-4LX25. This file contains information of modules positioning in the system, of the devices used for inputs and outputs of the system, and the positioning of bus-macros. After the files generation by the methodology, and the DynoPlace tool, it is possible to successfully execute the Early Access scripts for generating the DRS automatically.

La conception des systèmes de contrôle embarqués devient de plus en plus complexe en raison des algorithmes utilisés, de l'augmentation des besoins industriels et de la nature des domaines d'applications. Une façon de gérer cette complexité est de concevoir les contrôleurs correspondant en se basant sur des plateformes numériques puissantes et ouvertes. Plus précisément, cette thèse s'intéresse à l'utilisation des plateformes FPGA System-on-Chip (SoC) pour la mise en œuvre des algorithmes d'entraînement électrique pour des applications avioniques. Ces dernières sont caractérisées par des difficultés techniques telles que leur environnement de travail (pression, température élevée) et les exigences de performance (le haut degré d'intégration, la flexibilité). Durant cette thèse, l'auteur a contribué à concevoir et à tester un contrôleur numérique pour un variateur de vitesse synchrone qui doit fonctionner à 200 °C de température ambiante. Il s'agit d'une commande par flux orienté (FOC) pour une Machine Synchrone à Aimants Permanents (MSAP) associée à un capteur de type résolveur. Une méthode de conception et de validation a été proposée et testée en utilisant une carte FPGA ProAsicPlus de la société Actel/Microsemi. L'impact de la température sur la fréquence de fonctionnement a également été analysé. Un état de l'art des technologies basées sur les SoC sur FPGA a été également présenté. Une description détaillée des plateformes numériques récentes et les contraintes en lien avec les applications embarquées a été également fourni. Ainsi, l'intérêt d'une approche basée sur SoC pour des applications d'entrainements électriques a été démontré. D'un autre coté et pour profiter pleinement des avantages offertes par les SoC, une méthodologie de Co-conception matériel-logiciel (hardware-software (HW-SW)) pour le contrôle d'entraînement électrique a été proposée. Cette méthode couvre l'ensemble des étapes de développement de l'application de contrôle à partir des spécifications jusqu'à la validation expérimentale. Une des principales étapes de cette méthode est le partitionnement HW-SW. Le but est de trouver une combinaison optimale entre les modules à mettre en œuvre dans la partie logiciel et celles qui doivent être mis en œuvre dans la partie matériel. Ce problème d'optimisation multi-objectif a été réalisé en utilisant l'algorithme de génétique, Non-Dominated Sorting Genetic Algorithm (NSGA-II). Ainsi, un Front de Pareto des solutions optimales peut être déduit. L'illustration de la méthodologie proposée a été effectuée en se basant sur l'exemple du régulateur de vitesse sans capteur utilisant le filtre de Kalman étendu (EKF). Le choix de cet exemple correspond à une tendance majeure dans le domaine des contrôleurs embraqués pour entrainements électriques. Par ailleurs, la gestion de l'architecture du contrôleur embarqué basée sur une approche SoC a été effectuée en utilisant un système d'exploitation temps réel. Afin d'accélérer les services de ce système d'exploitation, une unité temps réel a été développée en VHDL et associée au système d'exploitation. Il s'agit de placer les services d'ordonnanceur et des processus de communication du système d'exploitation logiciel au matériel. Ceci a permis une accélération significative du traitement. La validation expérimentale d'un contrôleur du courant a été effectuée en utilisant un banc de test du laboratoire. Les résultats obtenus prouvent l'intérêt de l'approche proposée. / Designing embedded control systems becomes increasingly complex due to the growing of algorithm complexity, the rising of industrials requirements and the nature of application domains. One way to handle with this complexity is to design the corresponding controllers on performing powerful and open digital platforms. More specifically, this PhD deals with the use of FPGA System-on-Chip (SoC) platforms for the implementation of complex AC drive controllers for avionic applications. These latters are characterized by stringent technical issues such as environment conditions (pressure, high temperature) and high performance requirements (high integration, flexibility and efficiency). During this thesis, the author has contributed to design and to test a digital controller for a high temperature synchronous drive that must operate at 200°C ambient. It consists on the Flux Oriented Controller (FOC) for a Permanent Magnet Synchronous Machine (PMSM) associated with a Resolver sensor. A design and validation method has been proposed and tested using a FPGA ProAsicPlus board from Actel-Microsemi Company. The impact of the temperature on the operating frequency has been also analyzed. A state of the art FPGA SoC technology has been also presented. A detailed description of the recent digital platforms and constraints in link with embedded applications was investigated. Thus, the interest of a SoC-based approach for AC drives applications was also established. Additionally and to have full advantages of a SoC based approach, an appropriate HW-SW Co-design methodology for electrical AC drive has been proposed. This method covers the whole development steps of the control application from the specifications to the final experimental validation. One of the main important steps of this method is the HW-SW partitioning. The goal is to find an optimal combination between modules to be implemented in software and those to be implemented in hardware. This multi-objective optimization problem was performed with the Non-Dominated Sorting Genetic Algorithm (NSGA-II). Thus, the Pareto-Front of optimal solution can be deduced. The illustration of the proposed Co-design methodology was made based on the sensorless speed controller using the Extended Kalman Filter (EKF). The choice of this benchmark corresponds to a major trend in embedded control of AC drives. Besides, the management of SoC-based architecture of the embedded controller was allowed using an efficient Real-Time Operating System (RTOS). To accelerate the services of this operating system, a Real-Time Unit (RTU) was developed in VHDL and associated to the RTOS. It consists in hardware operating system that moves the scheduling and communication process from software RTOS to hardware. Thus, a significant acceleration has been achieved. The experimentation tests based on digital current controller were also carried out using a laboratory set-up. The obtained results prove the interest of the proposed approach.

Plusieurs types de dispositifs mécaniques (à vibration, à cylindre tournant, à lit fluidisé) mettant en jeu l'effet triboélectrique sont actuellement utilisés pour charger électriquement les constituants des mélanges de matériaux isolants granulaires, en vue de leur séparation dans un champ électrique intense. La non-uniformité de la charge des granules à la sortie de ces dispositifs affecte l'efficacité de la séparation, d'où l'intérêt des recherches visant la mise au point de procédés électrostatiques nouveaux, notamment pour des applications dans le domaine du recyclage des déchets. L'utilisation simultanée de l'effet triboélectrique, de la force de Coulomb et de la force d'image électrique est la solution innovante selon laquelle ont été conçus les quatre dispositifs à lit fluidisés réalisés ou améliorés dans le cadre de cette thèse. L'évaluation des performances de ces dispositifs a été rendue possible par la mise en oeuvre de systèmes de mesure complexes, permettant l'enregistrement continu et simultané des charges et des masses des produits de la séparation. Ainsi, la méthode des plans d'expériences pour surfaces de réponse a pu être utilisée pour modéliser le processus de séparation et déterminer les valeurs optimales des variables de contrôle de chacun des dispositifs, tels que le niveau de la haute tension d'alimentation ou la vitesse de l'air de fluidisation. Les résultats obtenus sur les installations de laboratoire et sur un prototype préindustriel recommandent cette classe de procédés tribo-aéro-électrostatiques comme la solution de choix pour le recyclage des déchets granulaires d'équipements électriques et électroniques. / Several types of mechanical devices (vibratory trays, rotating drums, fluidized beds) make use of the triboelectric effect for electrically charge the constituents of insulating materials granular mixtures, in view of their separation in a high-intensity electric field. The non-uniformity of granule charge at the exit of these devices adversely affects the separation efficiency, justifying the researches aimed at the development of novel electrostatic processes, mainly for applications in the field of waste recycling. Simultaneous usage of the triboelectric effect, the Coulomb force and the electric image force is an innovative technical solution according to which four fluidized bed devices were built or improved within the framework of this thesis. The performances of these devices could be evaluated by setting up complex measurement systems that enable the continuous and simultaneous recording of the charges and masses of the separated products. Thus, the experimental design methodology could be used for modeling the separation process and identify the optimum values of the control variables of each device, such as the high voltage level of the speed of the fluidization air. The results obtained on laboratory devices as well on an semi-industrial pilot installation recommend this class of tribo-aero-electrostatic separation processes as the solution of choice for the selective sorting of plastics from waste electric and electronic equipment.

The objective of this dissertation is to investigate the factors that influence the design of wide-area wavelength division multiplexing (WDM) optical networks. Wide-area networks are presented as communication networks capable of transporting voice and data communication over large geographical areas. These networks typically span a whole country, region or even continent.The rapid development and maturation of WDM technology over the last decade have been well-received commercially and warrants the development of skills in the field of optical network design.The fundamental purpose of all communication networks and technologies is to satisfy the demand of end-users through the provisioning of capacity over shared and limited physical infrastructure. Consideration of the business aspects related to communications traffic and the grooming thereof are crucial to developing an understanding of customer requirements in terms of the selection and quality of services and applications. Extensive communication networks require complex management techniques that aim to ensure high levels of reliability and revenue generation.An integrated methodology is presented for the design of wide-area WDM optical networks. The methodology harnesses physical, logical, and virtual topologies together with routing and channel assignment (RCA) and clustering processes to enhance objectivity of the design process. A novel approach, based on statistical clustering using the Ward linkage as similarity metric, is introduced for solving the problem of determining the number and positions of the backbone nodes of a wide-area network, otherwise defined as the top level hub nodes of the multi-level network model. The influence of the geographic distribution of network traffic, and the intra/inter-cluster traffic ratios are taken into consideration through utilisation of modified gravity models and novel network node weighting. / Dissertation (MEng)--University of Pretoria, 2005. / Electrical, Electronic and Computer Engineering / unrestricted

The thesis "Extending the methodology MMSP in test analysis and design" characterizes the discipline of test analysis and design carried out by its inclusion in the Methodology for small software projects (MMSP). The theoretical part defines the concept of discipline Test analysis and design and characterizes its role in the context of software testing and use in developing software products. It also analyzes attitude of commonly known models and methodologies of software development, certification, standards and norms in testing methodology including MMSP to the analytical activities in the field of testing. The practical part describes the methodology MMSP extension by discipline Test analysis and design, which allows the use of this discipline even on small projects developing uncritical IS/ICT solutions, which previously was not possible. Discipline Test analysis and design expands MMSP at considerable amount of analytical activities in the area of testing. Extending the methodology MMSP includes the introduction of new role Test analyst, modification of existing roles, the introduction of new products and descriptions of the recommended testing techniques and test design.

The overall objective of this study was to develop an optimised Ultra-High-Performance Concrete (UHPC) matrix based on the modified Andreasen and Andersen optimum particle packing model by using available South African materials. The focus of this study was to determine the optimum combined fibre and superplasticiser content for UHPC by using a response surface design. The UHPC was appropriately designed, produced and tested. Various changes in mechanical properties resulting from different combinations of steel fibre and superplasticiser contents was investigated. The flowability, density and mechanical properties of the designed UHPC were measured and analysed. Both the fibre and superplasticiser content play a significant role in the flowability of the fresh concrete. The addition of fibres significantly improved the strength of the concrete. The results show that the superplasticiser content can be increased if a more workable mix is required without decreasing the strength significantly. The statistical analysis of the response surface methodology confirms that the designed models can be used to navigate the design space defined by the Central Composite Design. The optimum combined fibre and superplasticiser content depend on the required mechanical properties and cost. Using the modified Andreasen and Andersen particle packing model and surface response design methodology, it is possible to efficiently produce a dense Ultra-High-Performance Fibre Reinforced Concrete (UHPFRC) with a relatively low binder amount, low fibre content and good workability. The effect of heat curing on the mechanical properties was investigated. It was concluded that heat curing is not recommended when considering the long-term strength development. The estimated strength development of concrete obtained by using the fib Model Code 2010 (2013) does not incorporate the detrimental effect of high curing temperatures on long-term strength and therefore overestimate the long-term strengths. The strength estimates for both early and long-term ages can be improved by considering this effect in the strength development functions obtained from fib Model Code 2010 (2013). The effect of specimen size on the compressive and flexural tensile strength of UHPFRC members were established. It was found that the specimen size has a significant effect on the measured cube compressive strength. Smaller beam specimens showed higher ductility compared to those of the larger beam specimens. The crack width decreased as the beam’s depth decreased. A lower variability was experienced in the beams with limited depth (< 45 mm). Further testing is required to determine whether a span-to-depth ratio of 10 would yield optimum results. The utilisation of by-products, such as undensified silica fume and fly ash, as cement replacement materials makes UHPFRC sustainable, leading to a reduced life-cycle cost. The calculated Embodied Energy per unit strength (EE/unit strength) and Embodied Carbon per unit strength (EC/unit strength) values for the UHPFRC mixture yield lower values compared to that of the 30 MPa concrete mixture, indicating that UHPFRC can be used to reduce the environmental footprint of the concrete industry. The inverse analysis method used was successful in providing an improved simplified stress-strain response for the UHPFRC. The analysis provided valuable information into the stress-strain, load-deflection and moment-curvature responses of the UHPFRC. Standard material test results were used to theoretically calculate moment-curvature responses and were then compared to the experimental results obtained. The study demonstrated that it is possible to efficiently produce a dense and workable UHPFRC with relatively low binder amount and low fibre content. This can result in more cost-effective UHPFRC, thus improving the practical application thereof. / Dissertation (MEng)--University of Pretoria, 2020. / Civil Engineering / MEng (Structural engineering) / Unrestricted

At one point or another we have all felt overwhelmed or stressed. It is part of human nature and can at times be beneficial as it can boost our performance and make us more alert. However when it becomes a part of daily life to worry about everything, it turns into a hindrance. This is where Iyashikei, the japanese word referring to the feeling of calm and relaxed, comes into play. We explore what makes a medium “Iyashikei” and define a design methodology based on those findings. The design methodology consists of three parts in which feelings and Iyashikei have been the main focus when deciding what to include. This design methodology is then evaluated by using it to design a game. The game is a small proof of concept design and can be expanded upon further to increase its calming effect. However we believe that it is sufficient as proof of concept.