Ce travail vise à améliorer la compréhension de la déformation locale des matériaux polycristallins. Pour cela, les comportements des grains individuels d'un polycristal d'aluminium déformé plastiquement sont étudiés par une approche couplant expériences in situ en synchrotron et simulation par élément finis.Dans l'expérience, la microstructure initiale est cartographiée par tomographie en contraste de diffraction (DCT). L'éprouvette est déformée en traction uniaxiale et 466 grains sont suivis par microscopie 3D par diffraction des rayons X (3DXRD) jusqu'à une déformation de 4.5%. De nouvelles méthodes d'analyse originales donnent accès aux orientations, déformations élastiques et contraintes, en moyenne par grain, et permettent de déterminer les distributions d'orientations intragranulaires à partir des données 3DXRD.Dans la simulation, la microstructure réelle (DCT) est modélisée par une partition de Laguerre, maillée finement et soumise au chargement expérimental. Les champs mécaniques et les champs d'orientations résultants peuvent être comparés aux données expérimentales.La comparaison entre expérience et simulation révèle un accord au premier ordre. Les rotations expérimentales montrent une forte variabilité associée à l'interaction intergranulaire et bien reproduite dans la simulation. Les distributions d'orientations ont des directions d'étalement privilégiées perpendiculaires à la direction de traction, ce qui est relié aux mécanismes de déformation du matériau. Les contraintes montrent un bon accord, dans la limite de la précision de mesure. Ces données, très riches, fournissent des pistes d'amélioration pour les modèles de plasticité cristalline. / This work aims to improve our understanding of the local deformation of polycrystalline materials. To this end, in situ synchrotron experiments and finite element simulations are coupled to study the individual grain responses in an aluminium polycrystal during plastic deformation.In the experiment, the initial microstructure is mapped by Diffraction Contrast Tomography (DCT). The specimen is deformed in uniaxial tension and 466 grains are followed by 3D X-Ray Diffraction (3DXRD) up to 4.5% plastic strain. New original analysis methods provide the grain average orientations, elastic strains and stresses, and allow determining the intra-grain orientation distributions from the 3DXRD measurements.In the simulation, the real microstructure (DCT) is modeled by a Laguerre tessellation, finely meshed and submitted to the experimental loading. The resulting mechanical and orientation fields can be compared to the experimental data.The comparison reveals a first-order agreement between experiment and simulation. The experimental rotations exhibit a high variability, associated to grain interaction and well reproduced in the simulation. The orientation distributions exhibit preferential spread directions perpendicular to the tensile direction, which can be related to the deformation mechanisms. Lastly, the stresses are found to be in agreement within the measurement accuracies. Such a rich dataset provides routes to improve crystal plasticity models.

<p>The initial goal of this report was to implement and compare cosine modulated filter banks. Because of time limitations, focus shifted towards the implementation. Filter banks and multirate systems are important in a vast range of signal processing systems. When implementing a design, there are several considerations to be taken into account. Some examples are word length, number systems and type of components. The filter banks were implemented using a custom made software, especially designed to generate configurable gate level code. The generated code was then synthesized and the results were compared. Some of the results were a bit curious. For example, considerable effort was put into implementing graph multipliers, as these were expected to be smaller and faster than their CSDC (Canonic Signed Digit Code) counterparts. However, with one exception, they turned out to generate larger designs. Another conclusion drawn is that the choice of FPGA is important. There are several things left to investigate, though. For example, a more thorough comparison between CSDC and graph multipliers should be carried out, and other DCT (Discrete Cosine Transform) implementations should be investigated.</p>

<p><p>The Dual Clutch Transmission (DCT) is a relatively new kind of transmission which shows increased efficiency and comfort compared to manual transmissions. Its construction is much like two parallell manual transmissions, where the gearshifts are controlled automatically. The gear-shift of a manual transmission involves a synchronization process, which synchronizes and locks the input shaft to the output shaft via the desired gear ratio. This process, which means transportation of a synchronizer sleeve, is performed by moving the gear shift lever which is connected to the sleeve. In a DCT, there is no mechanical connection between the gear-shift lever and the sleeve. Hence, an actuator system, controlled by a control system, must be used.</p><p>This report includes modelling, control system design and simulation results of a DCT synchronization process. The thesis work is performed at GM Powertrain (GMPT) in Trollhättan. At the time of this thesis, there is no DCT produced by GM, and therefore the results and conclusions rely on simulations. Most of the used system parameters are reasonable values collected from employees at GMPT and manual transmission literature.</p><p>The focus of the control design is to achieve a smooth, rather than fast, movement of the synchronizer sleeve. Simulations show that a synchronization process can be performed in less than 400 ms under normal conditions. The biggest problems controlling the sleeve position occur if there is a large amount of drag torque affecting the input shaft. Delay problems also worsen the performance a lot. An attempt to predict the synchronizer sleeve position is made and simulations shows advantages of that.</p><p>Some further work is needed before the developed control software can be used on a real DCT. Investigations of sensor noise robustness and the impact of dogging forces are the most important issues to be further investigated. Implementation of additional functionality for handling special conditions are also needed.</p></p>

<p><p>Benchmarking of DSP kernel algorithms was conducted in the thesis on a DSP processor for teaching in the course TESA26 in the department of Electrical Engineering. It includes benchmarking on cycle count and memory usage. The goal of the thesis is to evaluate the quality of a single MAC DSP instruction set and provide suggestions for further improvement in instruction set architecture accordingly. The scope of the thesis is limited to benchmark the processor only based on assembly coding. The quality check of compiler is not included. The method of the benchmarking was proposed by BDTI, Berkeley Design Technology Incorporations, which is the general methodology used in world wide DSP industry.</p><p>Proposals on assembly instruction set improvements include the enhancement of FFT and DCT. The cycle cost of the new FFT benchmark based on the proposal was XX% lower, showing that the proposal was right and qualified. Results also show that the proposal promotes the cycle cost score for matrix computing, especially matrix multiplication. The benchmark results were compared with general scores of single MAC DSP processors offered by BDTI.</p></p>

<p>In normal image coding the image quality is the same in all parts of the image. When it is known where in the image a single viewer is focusing it is possible to lower the image quality in other parts of the image without lowering the perceived image quality. This master's thesis introduces a coding scheme based on depth perception where the quality of the parts of the image that correspond to out-of-focus scene objects is lowered to obtain data reduction. To obtain further data reduction the method is combined with angular perception coding where the quality is lowered in parts of the image corresponding to the peripheral visual field. It is concluded that depth perception coding can be done without lowering the perceived image quality and that the coding gain increases as the two methods are combined.</p>

<p>The goal of this project was to implement and compare Invere Discrete Cosine Transform using three methods i.e. by bit parallel, digit serial and bit serial. This application describes a one dimensional Discrete Cosine Transform by bit prallel method and has been implemented by 0.35 ìm technology. When implementing a design, there are several considerations like word length etc. were taken into account. The code was implemented using WHDL and some of the calculations were done in MATLAB. The VHDL code was the synthesized using Design Analyzer of Synopsis; power was calculated and the results were compared.</p>

<p>This thesis describes the design of fast JPEG processing accelerators for a DSP processor. </p><p>Certain computation tasks are moved from the DSP processor to hardware accelerators. The accelerators are slave co processing machines and are controlled via a new instruction set. The clock cycle and power consumption is reduced by utilizing the custom built hardware. The hardware can perform the tasks in fewer clock cycles and several tasks can run in parallel. This will reduce the total number of clock cycles needed. </p><p>First a decoder and an encoder were implemented in DSP assembler. The cycle consumption of the parts was measured and from this the hardware/software partitioning was done. Behavioral models of the accelerators were then written in C++ and the assembly code was modified to work with the new hardware. Finally, the accelerators were implemented using Verilog. </p><p>Extension of the accelerator instructions was given following a custom design flow.</p>

<p>H.264 is a video coding standard which offers high data compression rate at the cost of a high computational load. This thesis evaluates how well parts of the H.264 standard can be implemented for a new multi-core digital signal processing processor architecture called ePUMA. The thesis investigates if real-time encoding of high definition video sequences could be performed. The implementation consists of the motion estimation, motion compensation, discrete cosine transform, inverse discrete cosine transform, quantization and rescaling parts of the H.264 standard. Benchmarking is done using the ePUMA system simulator and the results are compared to an implementation of an existing H.264 encoder for another multi-core processor architecture called STI Cell. The results show that the selected parts of the H.264 encoder could be run on 6 calculation cores in 5 million cycles per frame. This setup leaves 2 calculation cores to run the remaining parts of the encoder.</p>

<p>IDCT (Inverse Discrete Cosine Transform) is a common algorithm being used with image and sound decompression. The algorithm is a Fourier related transform which can occur in many different types like, one-dimensional, two-dimensional, three-dimensional and many more.</p><p>The goal with this thesis is to create a fast and low effect version of two-dimensional IDCT algorithm, where techniques as multiple-constant multiplication and subexpression sharing plus bit-serial and bit-parallel arithmetic are used.</p><p>The result is a hardware implementation with power consumption at 19,56 mW.</p>

De nombreux gènes sont surexprimés au cours de la progression du mélanome malin cutané. Pour mieux comprendre le rôle de ces gènes, des études fonctionnelles sont nécessaires. Mon projet visait à développer une nouvelle stratégie pour produire des souris portant n'importe quel ADN d'intérêt inséré à la place du premier exon du gène Dct. Dct code la dopachrome tautomérase, une enzyme de la voie de biosynthèse de la mélanine, exprimée de façon spécifique dans les mélanocytes et leurs précurseurs. Notre stratégie visait à augmenter la fréquence de recombinaison homologue au locus Dct dans des cellules souches embryonnaires (ES) en induisant une cassure double-brin à ce locus grâce aux propriétés endonucléases de la méganucléase I-SceI de levure. Nous avons créé une lignée de cellule ES qui portent un site unique de reconnaissance de la méganucléase I-SceI inséré dans l'intron 1 du gène Dct. Notre hypothèse était que l'induction d'une cassure double-brin au locus Dct serait recombinogène, et qu'en présence d'une matrice de réparation, la fréquence des recombinaisons homologues à ce locus serait augmentée de façon significative. Nous avons testé cette hypothèse et intégré successivement les gènes rapporteurs Lago1 et H2B-mCherry au locus Dct. Nos résultats indiquent que, de façon surprenante, l'induction d'une cassure double-brin ne favorise pas la recombinaison homologue au locus Dct. Nous avons analysé l'expression des gènes rapporteurs Lago1 et H2B-mCherry insérés au locus Dct dans des cellules en culture, l'embryon ou chez l'adulte