O trabalho trata do estudo do processo de impressão tridimensional e desenvolvimento de uma impressora para a produção de corpos-de-prova cerâmicos. A técnica de impressão tridimensional pertence ao grupo de prototipagem rápida e consiste na obtenção de um corpo sólido a partir de um modelo digital de três dimensões, através do fatiamento do modelo tridimensional e da impressão seqüencial de suas respectivas fatias. Durante o processo de impressão, deposita-se um ligante sobre camadas sucessivas de pó e em cada camada, o ligante consolida o pó no formato bidimensional da fatia, que por fim soma-se as outras fatias subseqüentes, consolidando assim o formato tridimensional do modelo. Os equipamentos convencionais de impressão 3D utilizam pós a base de gesso e acrílico, onde o ligante, a base de água, fornece a primeira adesão química; posteriormente é infiltrada uma resina para fornecer uma ligação com o pó de acrílico. Na impressão de cerâmica a base de alumina ou zircônia, o desenvolvimento de ligantes tem de ser realizado visando à adesão química e orgânica combinadas antes da sinterização. Neste projeto, uma mini impressora 3D para corpos de prova foi desenvolvida e com ela foram produzidos corpos de geometria simples e seção constante, cujo projeto, custo, manutenção simplificada e econômica possibilita também o emprego de materiais agressivos nos ligantes, com risco de danificação de componentes, a exemplo de ácido fosfórico, porém com baixo custo de recuperação. Foram analisados diversos tipos pelo dimensionamento de seus aglomerados, fluidez e densidade. Obteve-se pó a base de gesso por R$15,00 o kilograma. Corpos de prova foram analisados com relação à resistência mecânica por flexão de três pontos, densidade, porosidade aparente e imagens por microscopia ótica e microscopia eletrônica de varredura (MEV). Um protótipo de uma mini-impressora foi idealizado, projetado e fabricado, soluções originais e econômicas foram propostas e na sua validação alguns conceitos necessitam de melhorias, ainda assim foram obtidos resultados promissores. Foi desenvolvida uma formulação de pó baseado em gesso que teve o custo de aproximadamente 5% do produto importado. / The work studies the three-dimensional printing process and the development of a 3D printer to produce ceramic specimen. The 3D printing technique belongs to the rapid prototype group and consists in obtaining a solid body from a three-dimensions digital model, through the slicing of the three-dimensional model and the sequential printing of their respective slices. During the printing process, a binder is deposited upon successive powder layers, and in each layer, the binder consolidates the powder into the bi-dimensional shape of the slice, which ultimately adds to the other slices that followed, consolidating the three-dimensional shape model. The conventional 3D printing equipments uses powder based in gypsum and acrylic, where the water-based binder, provides the first chemical bind; subsequently is infiltrated a resin to provide a binding with the acrylic powder. In the ceramic printing based on alumina or zirconia, the development of binders must be accomplished looking for a organic and chemical bind before sintering. In this project, a mini 3D printer for ceramic specimens was developed and built, with it were be produced bodies of simple geometry and constant section, which design, cost and simplified maintenance and cost also enable the use of aggressive materials in binders, with the risk of components damage, such as phosphoric acid, but with low cost to recovery. Were analyzed several types of powders by the sizing of its clusters, fluidity and density. Were obtained gypsum powder for $ 7.00 a kilogram. The specimen were analyzed in relation to the mechanical strength by three-point bending, density, apparent porosity and images by optical microscopy and scanning electron microscopy (SEM). A prototype of a mini 3D printer was designed, engineered and manufactured, unique and economical solutions have been proposed and in its validation some concepts need of improvement, yet promising results were obtained. It was developed a powder formulation based on gypsum that has cost about 5% of the imported product.

The wide variety of interconnection structures presently nowadays for SoC (Systemon- Chip), bus and networks-on-Chip NoCs, each of them with a wide set of setup parameters, provides a huge amount of design alternatives. Although the interconnection structure is a key SoC component, there are few design tools in order to set the appropriate configuration parameters for a given application. An efficient SoC project may comply an exploration stage among the possible solutions for the communication structure, during the first steps of the design process. The absence of appropriate tools for that exploration makes critical the designer?s judgment. The present study aims to enhance the communication SoC structure design area, when a NoC is used. This work proposes a methodology that allows the establishment of the NoC communication parameters using a high level model (SystemC TLM timed). Our approach analyzes and evaluates the NoC performance under a wide variety of traffic conditions. The experimental stage was conducted employing a model of a net represented by a SystemC TLM timed (Hermes_Temp). Parametric and pseudo-random generators control the network traffic. The analysis was carried on with a tool designed for these purpose, which generates a group of performance metrics. The results allow to elucidate the global and inner network behavior. The performance values are useful for the heterogeneous and homogeneous NoC design projects, improving the performance evaluation studies scope. / The wide variety of interconnection structures presently nowadays for SoC (Systemon- Chip), bus and networks-on-Chip NoCs, each of them with a wide set of setup parameters, provides a huge amount of design alternatives. Although the interconnection structure is a key SoC component, there are few design tools in order to set the appropriate configuration parameters for a given application. An efficient SoC project may comply an exploration stage among the possible solutions for the communication structure, during the first steps of the design process. The absence of appropriate tools for that exploration makes critical the designer?s judgment. The present study aims to enhance the communication SoC structure design area, when a NoC is used. This work proposes a methodology that allows the establishment of the NoC communication parameters using a high level model (SystemC TLM timed). Our approach analyzes and evaluates the NoC performance under a wide variety of traffic conditions. The experimental stage was conducted employing a model of a net represented by a SystemC TLM timed (Hermes_Temp). Parametric and pseudo-random generators control the network traffic. The analysis was carried on with a tool designed for these purpose, which generates a group of performance metrics. The results allow to elucidate the global and inner network behavior. The performance values are useful for the heterogeneous and homogeneous NoC design projects, improving the performance evaluation studies scope.

Les principaux enjeux technico-scientifiques du 21ème siècle sont caractérisés par une interdisciplinarité et une convergence des technologies de plus en plus importantes. L'évolution des produits et services basés sur la bio- et la nanotechnologie sont parmi les exemples les plus connus. Il manque cependant des processus et des méthodes permettant d'organiser et de structurer la résolution de problème dans des environnements interdisciplinaires – ce terme faisant ici référence à la collaboration entre ingénieurs et chercheurs scientifiques.Ainsi, la question de recherche de ce travail de doctorat est la suivante :Comment soutenir et faciliter la résolution créative de problème interdisciplinaire et l'intégration des technologies dans des domaines basés sur la connaissance ?Pour répondre à cette question, trois hypothèses ont été formulées :La première hypothèse suggère que la composition d'un groupe en terme de disciplines (groupe multi- ou monodisciplinaire) a un impact sur le processus de résolution de problème en groupe ainsi que sur les résultats de ce processus.La deuxième hypothèse suggère un impact du support méthodologique sur le processus de résolution de problème en groupe ainsi que sur les résultats de ce processus.La troisième hypothèse suggère quant à elle que les concepts et notions clés des méthodes analytiques comme TRIZ et USIT peuvent être utilisés dans un processus d'intégration de technologie et peuvent soutenir ce processus.Les deux premières hypothèses ont été testées et validées par une expérimentation dans laquelle des groupes mono- et multidisciplinaires devaient générer des solutions pour un problème complexe en utilisant des méthodes intuitives ou analytiques. Alors que la composition de groupe impacte principalement les aspects quantitatifs et qualitatifs des solutions proposées, le support méthodologique influence quant à lui le processus de résolution de problème ainsi que les aspects qualitatifs des solutions. Plus important, l'impact des méthodes semble être dépendant de la composition des groupes.Pour tester la troisième hypothèse, les résultats de la première expérimentation ont été utilisés pour générer un modèle permettant de structurer la recherche et l'intégration d'une ou plusieurs technologies dans le cadre du développement de nouveaux produits. Ce modèle, qui intègre des méthodes et outils provenant de différentes méthodologies, a été testé par des ingénieurs lors d'une étude de cas industrielle dans le secteur des roulements à bille. L'évaluation du modèle montre qu'il semble faciliter le transfert de connaissance et améliorer la créativité des concepts développés comparé aux approches déjà existantes. En ce qui concerne l'effort nécessaire pour l'apprentissage et la mise en œuvre du modèle développé, les performances sont comparables à celles obtenues avec les méthodes préexistantes.Les résultats de ce travail sont particulièrement intéressants pour les équipes de la R et D et leur management dans les secteurs de la haute technologie ainsi que dans des domaines à l'interface entre l'ingénierie et les sciences naturelles. Le modèle développé est actuellement appliqué dans une démarche d'open innovation dans le secteur de la pharmacologie. / Most of the major technological challenges of the 21st century like e.g., reduction of greenhouse gas emission and sustainable energy supply, but also the bio- and nano-technological revolutions require intensified collaboration between different disciplines of engineering design as well as of natural science.The present Ph.D. research tries to provide some insight into the questions of• How to provide methodological support for creative problem solving in interdisciplinary groups composed of engineers and natural scientists?• How to support the process of the integration of a technology originating from a knowledge-intensive domain in order to solve a given design problem?The literature analyzed relevant aspects on several systemic levels (global, institutional, team-, individual and problem- perspective).The review allowed highlighting problems related to both, the activity as such as well as to the methods which seem a priori appropriate to support it. In this regard, incoherent interpretive schemes and majority influence are examples for the former and performance drawbacks as well as learning difficulties associated to hierarchical methodologies are instances of the latter.Based on the results of the literature review, two experiments were conducted.The first experiment inquired into the impact of disciplinary group composition (H1) as well as of the applied methodology (H2) on the creative group problem solving process and its outcomes.In a laboratory experiment 60 participants, 45 with a life science background and 15 with a mechanical engineering background were trained either in instances of intuitive approaches (Brainstorming, Mind Mapping) or in analytical, hierarchical methodology (TRIZ/USIT). Then, they had to solve an ill-defined medical problem in either mono- or multidisciplinary teams. The creative process as well as the output was documented using questionnaires and documentation sheets. Further the output was evaluated quantitatively by two domain experts before it was categorized qualitatively.Statistical analyses (ANOVA, Correlation parameters and Attraction rates), to a certain extent, support H1 and H2. More importantly however, the experiment shows differences related to method performance in general and as a function of disciplinary group composition in particular.The second experiment investigated whether concepts of TRIZ and its derivatives ((A/U)SIT) are appropriate to provide support for the process of technology integration before the background of an industrial NCD/NPPD process (H3).In order to test this hypothesis a model was developed which allows the identification and resolution of problems which typically appear during the integration of a specific technology into a given application. The model incorporates two of the most important concepts of TRIZ, and is sought to facilitate creative problem solving attempts in both, mono- and multidisciplinary teams.The said model was tested during an industrial NCD study in the roller bearing industry. After the case study, the participating engineers were asked to compare the applied model and the associated technology integration process with existing approaches used in the company.The results of the experiment point to superior performance of the presented model in terms of knowledge transfer-related and idea quality-related criteria. However, required resources for process conduction and necessary effort for the learning of the approach were considered comparable to existing approaches.The present Ph.D. work contributes to the understanding of creative problem solving in interdisciplinary groups in general and related to technology integration in particular. Especially the comparison of more pragmatic intuitive methods with more hierarchical analytical approaches depending on disciplinary group composition provided relevant insight for R&D processes.

The demand for higher quality steel and higher production rates in the production of steel slabs is ever increasing. These slabs are produced using a continuous casting process. The molten steel flow patterns inside the components of the caster play an important role in the quality of these products. A simple yet effective design method that yields optimum designs is required to design the systems influencing the flow patterns in the caster. The tundish is one of these systems. Traditionally, experimental methods were used in the design of these tundishes, making use of plant trials or water modelling. These methods are both costly and time consuming. More recently, Computational Fluid Dynamics (CFD) has established itself as a viable alternative to reduce the number of experimentation required, resulting in a reduction in the time scales and cost of the design process. Furthermore, CFD provides more insight into the flow process that is not available through experimentation only. The CFD process is usually based on a trial-and-error basis and relies heavily on the insight and experience of the designer to improve designs. Even an experienced designer will only be able to improve the design and does not necessarily guarantee optimum results. In this thesis, a more efficient design methodology is proposed. This methodology involves the combination of a mathematical optimiser with CFD to automate the design process. The methodology is tested on a four different industrial test cases. The first case involves the optimisation of a simple dam-weir configuration of a single strand caster. The position of the dam and weir relative to inlet region is optimised to reduce the dead volume and increase the inclusion removal. The second case involves the optimisation of a pouring box and baffle of a two-strand caster. In this case, the pouring box and baffle geometry is optimised to maximise the minimum residence time at operating level and a typical transition level. The third case deals with the geometry optimisation of an impact pad to reduce the surface turbulence that should result in a reduction in the particle entrainment from the slag layer. The last case continues from the third case where a dam position and height is optimised in conjunction with the optimised impact pad to maximise the inclusion removal on the slag layer. The cases studies show that a mathematical optimiser combined with CFD is a superior alternative compared to traditional design methods, in that it yields optimum designs for a tundish in a continuous casting system. / Thesis (PhD (Mechanical Engineering))--University of Pretoria, 2006. / Mechanical and Aeronautical Engineering / unrestricted

Orientador: Franco Giuseppe Dedini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-22T03:41:34Z (GMT). No. of bitstreams: 1 Duarte_AdrianaYumiSato_M.pdf: 12125505 bytes, checksum: 3905d87344e274e166ea8b7f129f87c3 (MD5) Previous issue date: 2013 / Resumo: A presente pesquisa tem como objetivo propor uma linguagem para a técnica artesanal de trançado manual, atividade praticada em diversas regiões do Brasil que utiliza materiais flexíveis para desenvolver produtos como cestos e esteiras, de modo a sistematizar a construção das armações e reafirmar a importância desta atividade para o país nos aspectos sociais, culturais e econômicos. Para tanto, o cenário desta pesquisa é baseado na análise da produção artesanal no Brasil, estudo do trançado manual e suas atividades análogas e a inserção das diretrizes de metodologia e ferramentas de projeto neste contexto. O conhecimento atrelado à prática do trançado manual é transmitido de forma oral e geracional, e em razão disto, está sendo perdido progressivamente. Por este motivo, como consequência da sistematização do trançado, o resgate deste conhecimento também é contemplado na pesquisa. Os resultados da pesquisa indicaram a relação entre o trançado manual e a tecelagem, atividade têxtil que transforma fios em tecidos, transferindo a nomenclatura, representação numérica e gráfica da tecelagem para o trançado manual. Assim, o que se pretende nesta pesquisa é sugerir uma linguagem para o trançado manual, ainda inexistente na área, que permita o desenvolvimento de um banco de dados e, futuramente, novas armações / Abstract: This research aims to propose a language for the artisanal braiding, a handicraft technique practiced in different regions of Brazil that uses flexible materials to develop products like baskets and mats, in order to systematize the construction and to reaffirm the importance of this activity in social, cultural and economic aspects. Therefore, the background of this research is based on the analysis of handicraft production in Brazil, the study of the braiding and its similar activities and the insertion of guidelines from methodology and design tools in this context. The knowledge linked to this practice is transmitted orally and between generations, and because of this, is being gradually lost. For this reason, as a consequence of the systematization of braiding, the rescue of this knowledge is also covered in this survey. The results indicated the relationship between artisanal braiding and weaving, a textile activity that transforms yarn into fabric, transferring the numerical and graphical representation for weaving to braiding. So, what is intended in this research is to suggest a language for artisanal braiding, which is lacking in the area, in order to allow the development of a database and, in future, new patterns / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestra em Engenharia Mecânica

L'alternateur à griffes est l'alternateur le plus utilisé dans l'industrie automobile. Afin d'augmenter sa puissance volumique, une solution classique consiste à utiliser des aimants NdFeB entre les griffes. Ces dernières années, le prix des aimants NdFeB a beaucoup augmenté remettant en question leur utilisation. Ce contexte implique de trouver de nouvelles solutions techniques permettant de conserver la même puissance volumique sans utiliser d'aimant NdFeB. Dans le cadre de ces travaux de thèse la solution proposée consiste a utiliser des matériaux magnétiques doux nobles tels que les FeCo (AFK18, AFK1 et AFK502). De part leur coût élevé, nous avons limité leur utilisation au noyau de l'alternateur même si leur utilisation au rotor est également évaluée. Ces travaux s'appuient sur une démarche de dimensionnement multi-niveaux (modèle reluctant et modèle éléments finis) ce qui apporte un bon compromis temps de calcul/précision. Une série d'études a été réalisée avec dans un premier temps, l'identification d'une géométrie de noyau favorable à l'utilisation de noyau en FeCo. Dans un second temps, une étude compare les courants batteries en fonction du FeCo utilisé au noyau avec une optimisation du rotor. Ensuite une étude présente le dimensionnement complet de l'alternateur (optimisation du rotor et du stator avec une étude sur le nombre optimal de paires de pôles) avec un noyau en AFK502 ce qui d'identifier le gain maximal en courant batterie apporté par l'utilisation d'un noyau en FeCo. Pour finir, une dernière étude compare les courants batteries en fonction du FeCo utilisé au rotor avec une optimisation du rotor et du stator. / Claw-pole alternators are often used in automotive industry. Permanent magnets like NdFEB are currently integrated to increased the power density of claw-pole machine. However their higher price brings into question their usage. This tight context implies finding new technical solutions to keep the same power density without NdFeB magnets. The solution adopted consists to evaluate the potential of gain with different soft magnetic materials and more especially FeCo family (AFK18, AFK1 et AFK502). Their higher price imposed us to use FeCo just at the core of the alternator but we have also evaluate their usage at the rotor. This work is based on an adapted design methodology including two modeling level (magnetic equivalent circuit model and finite element model) in order to obtain a good compromise between time computation/accuracy. Several studies have been made with, as a first step, the identification of new core geometry customized for FeCo core. As a second step, a study comparing output current according to FeCo used at the core is presented, rotor is optimized only. As a third step, is exposed the global optimization of the alternator with an AFK502 (rotor and stator optimization with a study on the optimal poles pairs number) in order to identify the maximum output current gain with an FeCo core. Finally, the last study compare output current according to FeCo used at the rotor, rotor and stator are optimized .

Orientador: Maria Gabriela Caffarena Celani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-27T01:58:13Z (GMT). No. of bitstreams: 1 Martino_JarryerAndradede_D.pdf: 15987793 bytes, checksum: e3e7fece0c549d866ab2fb31f75bd0c8 (MD5) Previous issue date: 2015 / Resumo: O projeto de arquitetura é composto por diferentes variáveis que precisam ser constantemente negociadas, algumas delas envolvem situações contraditórias, aumentando a complexidade da solução do problema. Os algoritmos evolutivos correspondem a um conjunto de técnicas que contribuem para a solução desse tipo de problema, e que podem ser incorporados ao sistema generativo de projeto de maneira a potencializar a obtenção de melhores resultados. Para isso, foi necessário entender a teoria evolucionista e os seus principais mecanismos, a estruturação e a implementação dos algoritmos evolutivos no ambiente computacional, e a sistematização do processo de projeto como base para o desenvolvimento de um método evolutivo. Dessa forma, foi definido um quadro teórico composto pelos principais eventos e conceitos relacionados à teoria evolucionista, à computação evolutiva e à discussão na década de 1960 sobre a sistematização do processo de projeto como uma sequência operativa capaz de registrar o processo mental do projetista, e o método evolutivo de projeto de arquitetura, sendo apresentada a sua estrutura, os componentes e exemplos. Embora esse método tivesse sido implementado na arquitetura na década de 1960, foi verificado que as aplicações estavam bastante restritas, limitando-se a trabalhos acadêmicos em universidades específicas. O domínio de uma linguagem de programação e a falta de clareza e apropriação dos vocabulários, conceitos e técnicas desenvolvidas pela Computação Evolutiva dificultaram a sua implementação como método de projeto na arquitetura e urbanismo. Atualmente, existem recursos digitais que facilitam a implementação desse método de maneira simplificada sem perder a eficiência do método, justificando a sua retomada como um método de projeto pelos arquitetos e urbanistas. Dessa forma, os objetivos desta pesquisa foram os de organizar o conteúdo teórico dos algoritmos evolutivos de maneira a esclarecer a sua estrutura, o vocabulário, os conceitos básicos e os mecanismos que os envolvem, de definir como ocorre a sua relação com o elemento arquitetônico e com o método de projeto, da identificação de uma ferramenta computacional capaz de facilitar a sua implementação e o de apresentar situações concretas em que os arquitetos e urbanistas possam utilizá-los. Como resultado foi possível verificar que não existe dificuldade no entendimento do mecanismo evolutivo como possível recurso para o desenvolvimento de um método de projeto, mas sim, a necessidade de maior domínio sobre a ferramenta de programação que não estaria relacionada diretamente com o sistema evolutivo, mas sim, com a descrição algorítmica através de um código computacional de todo processo de projeto / Abstract: The architecture design is composed by different variables that need to be negotiated, some of them involve contradictory situations, increasing the complexity of the solution. The evolutionary algorithms are set by techniques that contribute to obtain solutions for this kind of problems, and they also may be incorporated in a project generative system in a way that potentiate the best results obtaining. For this it was necessary to understand the evolutionary theory and its main mechanisms, the structuring and implementation of evolutionary algorithms in computational environment, and the systematization of the design process as a base of an evolutionary design method development. Thus, it was important to define a theoretical framework from the main events and concepts related to the evolutionary theory, the evolutionary computation and to the discussion in the 1960s about the systematization of the design process as an operative sequence capable of registering the mental process of the designer and the evolutionary design method on architecture with their components and examples. Although this method had been implemented in architecture in the 1960s, its application was quite restricted to academic works development in some specific universities. The necessity of the knowledge of programming language, vocabulary, concepts and techniques from evolutionary computation made the implementation difficult as a project method in architecture and urbanism. Currently, there are digital resources that facilitate the method simplified implementation without losing its efficiency, justifying its resumption as a design method by architects and urban planners. Moreover, the objectives of this research were to organize the content about evolutionary algorithms, clarifying its structure, vocabulary, basic concepts and the involved mechanisms, to define its relationship with the architectural element and the project method, to identify a computational tool that facilitates the implementation and to present the real situations which architects can use them. As a result it was possible to validate that there is no difficulty in understanding the evolutionary algorithm as possible resource for the methodology development of a design, yet, the necessity to have more experience in the utilization of programming tool. This tool is not directly related to the evolutionary system, but with the algorithmic description through the computational implementation by any project codes / Doutorado / Arquitetura, Tecnologia e Cidade / Doutor em Arquitetura, Tecnologia e Cidade

La technologie CMOS a contribué au développement de l'industrie des semi-conducteurs. Cependant, au fur et à mesure que le noeud technologique est réduit, la technologie CMOS fait face à des défis importants liés à la dissipation dûe aux courants de fuite et aux effets du canal court. Pour résoudre ce problème, les chercheurs se sont intéressés à la spintronique ces dernières années, compte tenu de la possibilité de fabriquer des dispositifs de taille réduite et d'opérations de faible puissance. La jonction tunnel magnétique (MTJ) est l'un des dispositifs spintroniques les plus importants qui peut stocker des données binaires grâce à la Magnétorésistance à effet tunnel (TMR). En dehors des applications de mémoire non volatile, la MTJ peut également être utilisée pour combiner ou remplacer les circuits CMOS pour implémenter un circuit hybride, de façon à combiner une faible consommation d'énergie et des performances à grande vitesse. Cependant, le problème de la conversion fréquente de charge en spin dans un circuit hybride peut entraîner une importante consommation d'énergie, ce qui obère l'intérêt pour des circuits hybrides. Par conséquent, le concept ASL qui repose sur un pur courant de spin comme support de l'information est proposé pour limiter les conversions entre charge et spin, donc pour réduire la consommation d'énergie. La conception de circuits à base de dispositif ASL entraîne de nombreux défis liés à l'hétérogénéité qu'ils introduisent et à l'espace de conception étendu à explorer. Par conséquent, cette thèse se concentre sur l'écart entre les exigences d'application au niveau du système et la fabrication des nanodispositifs. Au niveau du dispositif, nous avons développé un modèle compact intégrant le STT, la TMR, les effets d'injection/accumulation de spin, le courant de breakdown des canaux et le délai de diffusion de spin. Validé par comparaison avec les résultats expérimentaux, ce modèle permet d'explorer les paramètres du dispositif liés à la fabrication, tels que les longueurs de canaux et les tailles de MTJ, et aide les concepteurs à éviter leur destruction. De plus, ce modèle, décrit avec Verilog-A sur Cadence et divisé en plusieurs blocs : injecteur, détecteur, canal et contact, permet une conception indépendante et une optimisation des circuits ASL qui facilitent la conception de circuits hiérarchiques et complexes. En outre, les expressions permettant le calcul de l'injection/accumulation de spin pour le dispositif ASL utilisé sont dérivées. Elles permettent de discuter des phénomènes expérimentaux observés sur les dispositifs ASL. Au niveau circuit, nous avons développé une méthodologie de conception de circuit/système, en tenant compte de la distribution des canaux, de l'interconnexion des portes et des différents rapports de courant d'injection provoqués par la diffusion de spin. Avec les spécifications et les contraintes du circuit/système, les fonctions booléennes du circuit sont synthétisées en fonction de la méthode de synthèse développée et des paramètres de niveau de fabrication : longueur des canaux, et tailles MTJ sont spécifiées. Basé sur cette méthodologie développée, les circuits combinatoires de base qui forment une bibliothèque de circuits sont conçus et évalués en utilisant le modèle compact développé. Au niveau du système, un circuit DCT, un circuit de convolution et un système Intel i7 sont évalués en explorant les problèmes d'interconnexion : la répartition de l'interconnexion entre les portes et le nombre de tampons inséré. Avec des paramètres théoriques, les résultats montrent que le circuit/système ASL peut surpasser le circuit/système basé sur CMOS. De plus, le pipeline du circuit basé sur ASL est discuté avec MTJ comme tampons insérés entre les étapes. La reconfigurabilité provoquée par les polarités/valeurs du courant d'injection et les états des terminaux de control des circuits ASL sont également discutés avec l'exploration reconfigurable des circuits logiques de base. / The CMOS technology has tremendously affected the development of the semi-conductor industry. However, as the technology node is scaled down, the CMOS technology faces significant challenges set by the leakage power and the short channel effects. To cope with this problem, researchers pay their attention to the spintronics in recent years, considering its possibilities to allow smaller size fabrication and lower power operations. The magnetic tunnel junction (MTJ) is one of the most important spintronic devices which can store binary data based on Tunnel MagnetoResistance (TMR) effect. Except for the non-volatile memory, MTJ can be also used to combine with or replace the CMOS circuits to implement a hybrid circuit, for the potential to achieve low power consumption and high speed performance. However, the problem of frequent spin-charge conversion in a hybrid circuit may cause large power consumption, which diminishes the advantage of the hybrid circuits. Therefore, the ASL concept which uses a pure spin current to transport the information is proposed for fewer charge-spin conversions, thus for less power consumption. The design of ASL device-based circuits leads to numerous challenges related to the heterogeneity they introduce and the large design space to explore. Hence, this thesis focus on filling the gap between application requirements at the system level and the device fabrication at the device level. In device level, we developed a compact model integrating the STT, the TMR, the spin injection/accumulation effects, the channel breakdown current and the spin diffusion delay. Validated by comparing with experimental results, this model allows exploring fabrication-related device parameters such as channel lengths and MTJ sizes and help designers to prevent from device damages. Moreover, programmed with Verilog-A on Cadence and divided into several blocks: injector, detector, channel and contact devices, this model allows the independent design and cross-layer optimization of ASL-based circuits, that eases the design of hierarchical, complex circuits. Furthermore, the spin injection/accumulation expressions for the used ASL device are derived, enabling to discuss the experimental phenomena of the ASL device. In circuit level, we developed a circuit/system design methodology, taking into account the channel distribution, the gate interconnection and the different injection current ratios caused by the spin diffusion. With circuit/system specifications and constraints, the boolean functions of a circuit are synthesized based on the developed synthesis method and fabrication-level parameters: channel lengths, MTJ sizes are specified. Based on this developed methodology, basic combinational circuits that form a circuit library are designed and evaluated by using the developed compact model. In system level, a DCT circuit, a convolution circuit and an Intel i7 system are evaluated exploring the interconnection issues: interconnection distribution between gates and inserted buffer count. With theoretical parameters, results show that ASL-based circuit/system can outperform CMOS-based circuit/system. Moreover, the pipelining schema of the ASL-based circuit is discussed with MTJ as latches inserted between stages. The reconfigurability caused by the injection current polarities/values and the control terminal states of ASL-based circuits are also discussed with the reconfigurable exploration of basic logic circuits.

This thesis was developed to investigate the current models of sustainable development and architectural working and design practice and process to respond to the challenges of the current era defined as the Information Age. This thesis proposes a new model of sustainable development aligned to architecture and the Information Age, and a new integrated systems-design methodology to support it. Buildings were defined by le Corbusier in 1927 as ‘machines for living in’1 on the premise that these buildings facilitated our day-to-day user experience. The role of architecture as a facilitator for a sustainable existence is therefore subject to continued investigation. While there has been an increasing interest in environmental issues and ‘green building’, built environments have consequently failed to effectively holistically integrate core sustainable development principles in architecture. When compared to the definition of sustainable development in the UN Brundlandt Report of 1987, further research into an architectural design methodology is required to enable and plan for the long-term success of our built environments for current and, importantly, future generations. The practices and production of architecture risk being limited to reactively monitoring the design and construction processes for fixed moments in time, usually after the problem has presented itself. This is representative of localised, yet much publicised trends involving quantifiable rating systems for building performance. This does not contribute to long-term sustainability of the architectural product, nor the core principle of sustainable development to adequately meet the needs of current and future generations. The gravitation towards these easily-followed, yet limited-in-scope checklist processes is symptomatic of concepts of sustainable development remaining too broad and fragmented to facilitate focused, industry-appropriate implementation and design. The digital and information-based revolution has arrived, and humankind has now progressed to the point where constant and pervasive access to information and communication in a world of connected systems has changed the way we live and work. This is occurring at an exponential rate within what have been termed ‘knowledge-based societies’. Furthermore, the influence of the Information Age continues to manifest itself in the built environment through advancement of concepts and initiatives such as Smart Cities, intelligent buildings, and the Internet of Things. However, architectural approach and its emphasis on the building as a finite product comes at the expense of a holistic and integrated systems approach, and therefore requires investigation towards a revised design methodology. This thesis will begin by investigating the concept of sustainable development from its original inception to existing interpretations, and will interrogate its continued significance as a decades-old concept to the Information Age. This will be undertaken on the basis that sustainable development primarily aligns itself to the needs of humankind (current and future generations) and as such remains timeless as a core concept. However, the criteria that define sustainable development require investigation based on: a) their suitability towards human need in the context of knowledge-based societies and the Information Age, as well as b) their appropriateness for focused implementation in the scope of the built environment. In this aim, newly proposed criteria will be assimilated into a revised model for sustainable development, from which a methodology for design is developed. This will address the nature of the architectural process towards the creation of sustainable building solutions as a function of a systems approach, rather than a product approach. An integrated systems-design methodology is proposed, promoting the evolution of sustainable development theory in architecture for greater applicability to the Information Age. This systems-design methodology proactively identifies criteria for solving a given problem and the development of alternative solutions, while the proposed revised model for sustainable development is integrated to achieve a holistic building solution based on a systems process. This is inclusive of product (systems solution) delivery into the operation phase. The designer and project information model therefore transition into ‘information custodian’ and repository for knowledge gathering and exchange respectively, to the benefit of current and future stakeholders. This is addressed through various stages in design development and implementation, which apply contextually-based requirements of proposed sustainable development criteria, while catering for aspects of future flexibility, user experience, and knowledge-based development. This methodology expects the design practitioner to apply multi-dimensional evaluation and assessment tools at their discretion, and accommodate changing project dynamics over its life cycle. This implementation will benefit from future research and the introduction of new technologies to aid the process. This may furthermore be affected by new regulatory policy and guidelines affecting architects and the built environment. / Thesis (PhD)--University of Pretoria, 2018. / Architecture / PhD / Unrestricted

The number of electric powered sub-systems in road-vehicles is increasing fast. This development is primarily driven by the new and improved functionality that can be implemented with electro-mechanical sub-systems, but it is also necessary for the transition to electric and hybrid-electric drive trains. An electromechanical sub-system can be implemented as a physically integrated mechatronic module: controller, power electronics, electric motor, transmission and sensors, all integrated into one component. A mechatronic module, spans, as all mechatronic systems, over several closely coupled engineering disciplines: mechanics, electronics, electro-mechanics, control theory and computer science. In order to design and optimize a mechatronic system it is therefore desirable to design the system within all domains concurrently. Optimizing each domain or component separately will not result in the optimal system design. Furthermore, the very large production volumes of automotive sub-systems increase the freedom in the mechatronics design process. Instead of being limited to the selection from off-the shelf components, application specific components may be designed. The research presented in this thesis aims at development of an integrated design and optimization methodology for mechatronic modules. The target of the methodology is the conceptual design phase, where the number of design parameters is relatively small. So far, the focus has been on design methods for the electric motor and gearhead, two of the most important components in an actuation module. The thesis presents two methods for design and optimization of motor and gearhead in mechatronic applications. One discrete method, intended for the selection of off-the-shelf components, and one method mainly intended for high volume applications where new application specific components may be designed. Both methods can handle any type of load combination, which is important in mechatronic systems, where the load seldom can be classified as pure inertial or constant speed. Furthermore, design models relating spur gear weight, size and inertia to output torque and gear ratio are presented. It is shown that a gearhead has significantly lower inertia and weight than a motor. The results indicate that it almost always is favorable from a weight and size perspective to use a gearhead. A direct drive configuration may only be lighter for very high speed applications. The main contribution of this thesis is however the motor/gear ratio sizing methods that can be applied to any electromechanical actuation system that requires rotational motion. / QC 20101220