Reconfigurable computing systems require supports from powerful computer aided design tools to help users developing the interactions between software programs and hardware circuits. The placement and routing support for reconfigurable processing units is also the key to the efficiency of the computing system. In this thesis, we implemented the placement and routing tool for the FMRPU (Fine-grain Multi-context Reconfigurable Processing Unit). The routing resource among the Logic Arrays supports only 8-bit aligned data width, so the routing of the FMRPU can¡¦t completely imitate from the pattern used by LUT-based routing. Thus we proposed an operation-based design model which accepts a data flow graph that describes the operations of the circuit. After compressing the graph, the tool uses Simulated Annealing algorithm with either Maze Route or Center-of-Gravity Route to map the compressed graph into FMRPU. Through the placement and routing tool we implemented, we have successfully mapped several algorithms used in multi-media applications, such as FFT and DCT, into FMRPU.

名古屋大学年代測定総合研究センターシンポジウム報告

Because of its low density and high strength, magnesium (Mg) and its alloys are being sought after in the automotive industry for structural applications. Although many road-going cars today contain cast Mg parts, in the fabrication of chassis structural members the wrought alloys are required. One of the challenges of fabrication with wrought Mg is welding and joining the formed sheets. Because of the commonly observed difficulties in fusion welding of Mg such as hot cracking and severe Heat Affected Zone (HAZ), this work aimed to establish the feasibility of the solid-state process Magnetic Pulse Welding in producing lap welds of Mg sheet. Mg AZ31 alloy sheets have been lap-welded with Magnetic Pulse Welding (MPW), an Impact Welding technique, using H-shaped symmetric coils connected to a Pulsar MPW-25 capacitor bank. MPW uses the interaction between two opposing magnetic fields to create a high speed oblique collision between the metal surfaces. The oblique impact sweeps away the contaminated surface layers and forces intimate contact between clean materials to produce a solid-state weld. Various combinations of similar and dissimilar metals can be welded using MPW. Other advantages of MPW are high speed, high strength, and the possibility of being mounted on a robotic arm. The present research focuses on the feasibility and mechanical performance of an MPW weld of 0.6 mm AZ31 Mg alloy sheets made in a lap joint configuration. Tensile shear tests were carried out on the joints produced. Load bearing capacity showed linear increase with capacitor bank discharge energy up to a certain value above which a parabolic increase was seen. Strength was estimated to be at least as high as base metal strength by measuring the fracture surface area of selected samples. The fracture surface of samples welded at higher discharge energy showed two regions. In the beginning of the bond a platelet-featured fracture brittle in appearance and a ductile, micro-voiding fracture in the latter part. The joint cross section morphology consisted of a flattened area that had two symmetric bond zones 1 mm wide each separated by an unbonded centre zone ~3mm wide. Reasons for the morphology were presented as a sequence of events based on the transient nature of the oblique collision angle. The interface microstructure was studied by optical and electron microscopy. Examination of the bonds has revealed sound and defect free interfaces. No microcracking, porosity, resolidification, or secondary phase formation was observed. Metallographic examination of the unbonded centre zone revealed anisotropic deformation and a lack of cleaning from the interface. This zone is formed as a result of normal impact in the initial stage of collision. The bond zone interface of the joint was characterized by a smooth interface consisting of refined grains. In samples welded at higher energy interfacial waves developed in the latter half of the bond zone. Transmission electron microscopy (TEM) of the bond zone revealed a continuous interface having an 8-25 μm thick interlayer that coincided with the waves and had a dislocation cell structure and distinct boundaries with adjacent material. Equiaxed 300 nm dynamic recrystallized (DRX) grains were found adjacent to the interlayer as well as other slightly larger elongated grains. The interlayer is thought to be formed in plasticized state at elevated temperature through severe shear strain heating. The interlayer corresponds to a ductile fracture surface and, along with the interfacial waves, is responsible for the joint’s high strength.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19708号 / 工博第4163号 / 新制||工||1642(附属図書館) / 32744 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 辻 伸泰, 教授 白井 泰治, 教授 乾 晴行 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Esta Dissertação apresenta um modelo de paralelismo de grão fino para utilização em aplicações baseadas em objetos distribuídos. A pesquisa é desenvolvida sobre o modelo de distribuição de objetos da linguagem DPC++, uma extensão de C++ concebida na Universidade Federal do Rio Grande do Sul. A motivação para o desenvolvimento deste modelo é a crescente disponibilidade de arquiteturas multiprocessadas e de tecnologias de comunicação de alto desempenho, o que permite o aproveitamento eficiente de um nível de concorrência de menor granularidade. O objetivo do trabalho é integrar de forma adequada e eficiente a utilização de tal nível de concorrência no modelo original de distribuição de objetos de DPC++, permitindo que as aplicações desenvolvidas com a linguagem possam explorar ao máximo o poder computacional oferecido pelas arquiteturas citadas. Como principais características, o modelo proposto apresenta a capacidade de concorrência entre os métodos de um mesmo objeto distribuído e a introdução de um mecanismo de sincronização baseado na semântica de monitores. Os resultados obtidos com a implementação de uma aplicação de geração de fractais de Mandelbrot demonstram que, em termos de desempenho, o modelo apresentado efetivamente atinge seus objetivos. Além disso, a extinção a sintaxe original de programação de DPC++ revela importante contribuição no sentido de aumentar o poder de expressão da linguagem para o desenvolvimento de aplicações paralelas. / This Thesis presents a fine-grain concurrency model for applications based on distributed objects. The basis for the development of this research is the model of distribution of objects presented by the language DPC++, an extension of C++ conceived at the Federal University of Rio Grande do Sul. The motivation for the development of this model is the growing availability of multiprocessor architectures and high-performance communication technologies, which allows for the efficient use of a finer grain of concurrency. The purpose of this work is to efficiently integrate such level of concurrency into the original model of distribution of objects of DPC++, making it possible for the applications developed with the language to thoroughly explore the computational power offered by the mentioned architectures. As main features the proposed model presents the possibility of concurrency between the methods of a single distributed object and the introduction of a synchronisation mechanism based on the semantics of monitors. The results obtained with the implementation of aMandelbrot fractal generation application showthat, in relation to performance, the presented model effectively reaches its purposes. In addition, the extension to the original programming sintax of DPC++ reveals an important contribution towards a higher expressivity degree in the development of parallel applications.

Dans le contexte du développement durable, et dans un objectif de limitation de l’impact environnemental, le recours à des sols fins prend une place croissante dans la construction d’ouvrages en terre. Mais la maîtrise de ces matériaux amène au cours de l’exécution des difficultés lors du compactage, telles que le feuilletage et le matelassage. Au sein du projet ANR TerreDurable, cette thèse vise à l’étude du compactage, plus particulièrement pour les marnes proches de la saturation. Le programme d’essais se base principalement sur les observations apportées par les praticiens (Vinci Construction Terrassement, Valerian, Egis Géotechnique), pour parvenir à des essais mettant en évidence difficultés et mauvais usages rencontrés. Après une discussion sur l’effet des méthodes de contrôle de succion sur la nucléation dans les sols fins, l’étude porte sur une planche de compactage in situ. Elle s’articule autour de 4 paramètres : teneur en eau, mouture, type de compacteur et énergie de compactage. Ces variations mènent à la réalisation de 24 plots sortants parfois du cadre règlementaire, incarné en France par le Guide des Terrassements Routiers (GTR). Une fois terminés, et après des observations visuelles, les plots subissent carottages et pénétromètres dynamiques pour évaluer l’état et la réponse hydromécanique du matériau. Les mesures recueillies permettent de fournir des informations quant aux bonnes pratiques de compactage, mais aussi vis-à-vis des variables d’état du sol selon le jeu de paramètre. Dans un deuxième temps, l'effet de la préparation du matériau est étudié dans la cadre d'essais Proctor et IPI. Le matériau de chaque essai est alors exploité pour la réalisation de courbes de retentions dans le domaine quasi saturé. Toutes ces mesures sont alors comparées à la planche, de manière à cadrer les essais de cette dernière et confirmer les observations faites en première instance. Pour finir, une cellule triaxiale de révolution est développée dans l'objectif d’étudier l’évolution des variables d’état du sol au cours du compactage. Elle présente un tensiomètre à sa base, mais aussi des fenêtres planes en plexiglas pour permettre l’utilisation de la corrélation d’images pour l’estimation des changements de volume. Ces fenêtres ont pour objectif de limiter les déformations optiques et faciliter la mesure. La conception et la calibration de la cellule sont présentées, tout en mettant en avant sa précision. Sont alors réalisés les premiers essais de reproduction du compactage, basés sur des références in situ. Malgré les difficultés rencontrées pour simuler les passes d’un compacteur au sein de la cellule, les essais apportent des éléments de réflexion quant à l’effet de ce dernier sur le sol. / In the context of sustainable development, and to limit environmental impact, usage of fine-grained soils takes an expending place in earthworks. Sadly, the control of such materials through construction leads to difficulties during compaction, such as lamination and wave effect. As part of the French ANR project TerreDurable, this thesis aims to research compaction, mostly marls close to saturation. Observations carried out by practitioners serves as base for the experimental programme (Vinci Construction Terrassement, Valerian, Egis Géotechnique), to achieve surveys showing the main known difficulties and poor usages. After a discussion on the effect of measurement methods on nucleation in fine-grained soils, the study follows a full-scale in situ compaction test, articulated around four parameters: water content, grinding, compactor type and compaction energy. These variations lead 24 parcels sometimes out of the French legal frame (Guide des Terrassement Routiers). After realisation and visual observations, each of the parcels undergoes samplings and dynamic penetrometers to evaluate their state and hydro mechanical response. These analyses give data regarding good compaction practice, but also soil state variables after compaction. Then, proctor and CBR tests first show the effect of soil preparation on their outcomes. Afterwards, retention curves in the quasi-saturated domain are conducted from the Proctors. These measures compared to the full scale in situ compaction test, provide a frame to its results and confirm initial observations. Finally, aiming to study state variables evolution during compaction, a triaxial cell is developed. Equipped with a tensiometer at its base, flat Plexiglas windows are created enabling digital image correlation (DIC) for volume changes assessments. These windows allow for limited optical deformations and measurement facilitation. The conception and the calibration of the cell are presented to evaluate its precision. Then, the first tests to reproduce compaction, based on in-situ references, are carried out. Despite difficulties to simulate compactor passes in the cell, it provided elements of reflexion regarding the effect of compaction.

The improvement in mechanical strength offered by ultra fine- (UF) and nanocrystalline (NC) sized grains is very attractive for potential applications of structural metals. Accumulative Roll-Bonding (ARB) is one of the promising new techniques for producing bulk UF grained metals. There are numerous reports on the monotonic mechanical behavior of various ARBed metals, however there are few, if any, on the cyclic deformation behavior of such metals. The primary objective of this study is to investigate the cyclic deformation behaviour and the related micro-mechanisms of ARBed metals from a fundamental perspective. To achieve this, the microstructure and the deformation behavior of commercial purity aluminum, OFHC copper, and DLP copper after ARB processing have been systematically characterized. The as-ARBed microstructure is found to be composite natured, with constituents of different grain sizes. The three constituents are: (i)UF grained matrix, (ii)NC primary discontinuities, and (iii)conventional sized pre-existing coarse grains. Due to this composite nature, three different cyclic strain accommodation mechanisms were found in the ARBed OFHC copper: (i)conventional dislocation patterns in the large grains, (ii)reactivation of pre-existing shear bands, and (iii)stress/strain driven grain coarsening at sites of strain localization. The order of activation of the mechanisms can be described with a composite approach based on activation energy. The occurrence of grain coarsening is the major contributor to the cyclic softening response observed in OFHC copper. Conversely, the lesser extent of cyclic softening in the other two metals is likely due to the higher microstructure stability of the initial as-ARBed materials. The microstructure stability is believed to be the primary influencing factor for the extent of grain coarsening and cyclic softening. The applied cyclic plastic strain is a secondary influencing factor, although this is generally overshadowed by the limitation of grain coarsening due to the short cyclic lifespan of these metals. The occurrences of shear banding and grain coarsening reported in the present ARBed metals are similarly reported for UF grained metals from other processes, e.g. ECAPed metals. Thus, its relationship to the cyclic deformation response and governing factors are believed to be applicable for UF grained metals in general.

The improvement in mechanical strength offered by ultra fine- (UF) and nanocrystalline (NC) sized grains is very attractive for potential applications of structural metals. Accumulative Roll-Bonding (ARB) is one of the promising new techniques for producing bulk UF grained metals. There are numerous reports on the monotonic mechanical behavior of various ARBed metals, however there are few, if any, on the cyclic deformation behavior of such metals. The primary objective of this study is to investigate the cyclic deformation behaviour and the related micro-mechanisms of ARBed metals from a fundamental perspective. To achieve this, the microstructure and the deformation behavior of commercial purity aluminum, OFHC copper, and DLP copper after ARB processing have been systematically characterized. The as-ARBed microstructure is found to be composite natured, with constituents of different grain sizes. The three constituents are: (i)UF grained matrix, (ii)NC primary discontinuities, and (iii)conventional sized pre-existing coarse grains. Due to this composite nature, three different cyclic strain accommodation mechanisms were found in the ARBed OFHC copper: (i)conventional dislocation patterns in the large grains, (ii)reactivation of pre-existing shear bands, and (iii)stress/strain driven grain coarsening at sites of strain localization. The order of activation of the mechanisms can be described with a composite approach based on activation energy. The occurrence of grain coarsening is the major contributor to the cyclic softening response observed in OFHC copper. Conversely, the lesser extent of cyclic softening in the other two metals is likely due to the higher microstructure stability of the initial as-ARBed materials. The microstructure stability is believed to be the primary influencing factor for the extent of grain coarsening and cyclic softening. The applied cyclic plastic strain is a secondary influencing factor, although this is generally overshadowed by the limitation of grain coarsening due to the short cyclic lifespan of these metals. The occurrences of shear banding and grain coarsening reported in the present ARBed metals are similarly reported for UF grained metals from other processes, e.g. ECAPed metals. Thus, its relationship to the cyclic deformation response and governing factors are believed to be applicable for UF grained metals in general.

Esta Dissertação apresenta um modelo de paralelismo de grão fino para utilização em aplicações baseadas em objetos distribuídos. A pesquisa é desenvolvida sobre o modelo de distribuição de objetos da linguagem DPC++, uma extensão de C++ concebida na Universidade Federal do Rio Grande do Sul. A motivação para o desenvolvimento deste modelo é a crescente disponibilidade de arquiteturas multiprocessadas e de tecnologias de comunicação de alto desempenho, o que permite o aproveitamento eficiente de um nível de concorrência de menor granularidade. O objetivo do trabalho é integrar de forma adequada e eficiente a utilização de tal nível de concorrência no modelo original de distribuição de objetos de DPC++, permitindo que as aplicações desenvolvidas com a linguagem possam explorar ao máximo o poder computacional oferecido pelas arquiteturas citadas. Como principais características, o modelo proposto apresenta a capacidade de concorrência entre os métodos de um mesmo objeto distribuído e a introdução de um mecanismo de sincronização baseado na semântica de monitores. Os resultados obtidos com a implementação de uma aplicação de geração de fractais de Mandelbrot demonstram que, em termos de desempenho, o modelo apresentado efetivamente atinge seus objetivos. Além disso, a extinção a sintaxe original de programação de DPC++ revela importante contribuição no sentido de aumentar o poder de expressão da linguagem para o desenvolvimento de aplicações paralelas. / This Thesis presents a fine-grain concurrency model for applications based on distributed objects. The basis for the development of this research is the model of distribution of objects presented by the language DPC++, an extension of C++ conceived at the Federal University of Rio Grande do Sul. The motivation for the development of this model is the growing availability of multiprocessor architectures and high-performance communication technologies, which allows for the efficient use of a finer grain of concurrency. The purpose of this work is to efficiently integrate such level of concurrency into the original model of distribution of objects of DPC++, making it possible for the applications developed with the language to thoroughly explore the computational power offered by the mentioned architectures. As main features the proposed model presents the possibility of concurrency between the methods of a single distributed object and the introduction of a synchronisation mechanism based on the semantics of monitors. The results obtained with the implementation of aMandelbrot fractal generation application showthat, in relation to performance, the presented model effectively reaches its purposes. In addition, the extension to the original programming sintax of DPC++ reveals an important contribution towards a higher expressivity degree in the development of parallel applications.

Esta Dissertação apresenta um modelo de paralelismo de grão fino para utilização em aplicações baseadas em objetos distribuídos. A pesquisa é desenvolvida sobre o modelo de distribuição de objetos da linguagem DPC++, uma extensão de C++ concebida na Universidade Federal do Rio Grande do Sul. A motivação para o desenvolvimento deste modelo é a crescente disponibilidade de arquiteturas multiprocessadas e de tecnologias de comunicação de alto desempenho, o que permite o aproveitamento eficiente de um nível de concorrência de menor granularidade. O objetivo do trabalho é integrar de forma adequada e eficiente a utilização de tal nível de concorrência no modelo original de distribuição de objetos de DPC++, permitindo que as aplicações desenvolvidas com a linguagem possam explorar ao máximo o poder computacional oferecido pelas arquiteturas citadas. Como principais características, o modelo proposto apresenta a capacidade de concorrência entre os métodos de um mesmo objeto distribuído e a introdução de um mecanismo de sincronização baseado na semântica de monitores. Os resultados obtidos com a implementação de uma aplicação de geração de fractais de Mandelbrot demonstram que, em termos de desempenho, o modelo apresentado efetivamente atinge seus objetivos. Além disso, a extinção a sintaxe original de programação de DPC++ revela importante contribuição no sentido de aumentar o poder de expressão da linguagem para o desenvolvimento de aplicações paralelas. / This Thesis presents a fine-grain concurrency model for applications based on distributed objects. The basis for the development of this research is the model of distribution of objects presented by the language DPC++, an extension of C++ conceived at the Federal University of Rio Grande do Sul. The motivation for the development of this model is the growing availability of multiprocessor architectures and high-performance communication technologies, which allows for the efficient use of a finer grain of concurrency. The purpose of this work is to efficiently integrate such level of concurrency into the original model of distribution of objects of DPC++, making it possible for the applications developed with the language to thoroughly explore the computational power offered by the mentioned architectures. As main features the proposed model presents the possibility of concurrency between the methods of a single distributed object and the introduction of a synchronisation mechanism based on the semantics of monitors. The results obtained with the implementation of aMandelbrot fractal generation application showthat, in relation to performance, the presented model effectively reaches its purposes. In addition, the extension to the original programming sintax of DPC++ reveals an important contribution towards a higher expressivity degree in the development of parallel applications.