Quantum annealing represents an essential milestone towards the goal of adiabatic quantum computing. In quantum annealing, the computation involves finding the ground state of a classical Ising-like Hamiltonian realized as interactions between qubits. Quantum fluctuations are introduced to allow the wavefunction of the qubits to explore the energy landscape, the hope being that the wavefunction finds a minimum energy configuration and possibly giving the result of the computation. While quantum annealing likely may not be as powerful as adiabatic quantum computing, it is possible that it may be better at optimization compared to analogous classical algorithms. In physical realizations of quantum annealing, there are still questions as to the role of quantum fluctuations in the operation of a device given the short coherence times of the individual qubits. These questions have consistently posed a serious theoretical challenge making it difficult to verify experimental results. Here we simplify the problem by considering a system of qubits with ferromagnetic interactions, modeling the decoherence effects as classical noise in the transverse-field of each qubit. We compare the calculations to data collected from a system of manufactured qubits produced by D-wave Systems by performing a finite-size scaling analysis that captures the competition between quantum fluctuations of the transverse-field and bit-flip errors from the noise. We argue that on time-scales larger than the single-qubit decoherence time, the device produces the expected quantum fluctuations for the many-body system. Using this finite-size scaling, one can diagnose sources of noise in the system. Hopefully, in the near future, these devices will not only be realizing coherent quantum annealing but will likely be useful as another example of synthetic quantum matter.

Increased levels of science objectives expected from spacecraft systems necessitate the ability to carry out fast on-board autonomous mission planning and scheduling. Heterogeneous radiation-hardened Field Programmable Gate Arrays (FPGAs) with embedded multiplier and memory modules are well suited to support the acceleration of scheduling algorithms. A methodology to design circuits specifically to accelerate Simulated Annealing Kernels (SAKs) in event scheduling algorithms is shown. The main contribution of this thesis is the low complexity scoring calculation used for the heuristic mapping algorithm used to balance resource allocation across a coarse-grained pipelined data-path. The methodology was exercised over various kernels with different cost functions and problem sizes. These test cases were benchedmarked for execution time, resource usage, power, and energy on a Xilinx Virtex 4 LX QR 200 FPGA and a BAE RAD 750 microprocessor.

Depuis quelques années, les polyoléfines et en particulier le Polyéthylène présentent un intérêt économique qui se traduit par un marché en croissance constante. Cependant, il est souvent nécessaire d’améliorer leurs propriétés d’usage notamment pour des problématiques liées à l’industrie automobile. Dans ce contexte, une amélioration des propriétés thermomécaniques et barrière aux vapeurs et liquides du Polyéthylène sur une gamme de température étendue constitue un nouveau challenge scientifique et environnemental. Dans cette étude, nous avons tout d’abord étudié l’impact de charges inorganiques et d’un recuit à 125°C sous air sur les propriétés thermomécaniques d’un HDPE. Le deuxième axe de recherche s’est concentré sur l’amélioration des propriétés barrière aux essences de ce polymère en favorisant les charges lamellaires pour leur haut facteur de forme induisant un effet de tortuosité élevé. L’impact de ce type de charges sur les phénomènes de sorption et d’extraction a été étudié dans le but de définir une formulation à base HDPE optimale pour limiter la perte physique d’oligomères et d’antioxydants. Le but de ces travaux étant de mieux comprendre les différents mécanismes mis en jeu, nous avons cherché à établir les relations Structure / Morphologie / Propriétés pour les deux axes d’étude développés / In the recent years, the use of polyolefin and especially Polyethylene are of economic interest resulting in a growing attention concerning the improvement of its properties of use, especially for automotive application. In this context, the reinforcement of its thermomechanical properties and the improvement of its barrier properties to different fuels over an extended temperature range constitute a major scientific and environmental challenge. In this study, we first decided to analyze the impact of silica particles and of an annealing at 125°C under air atmosphere on thermomechanical properties of a HDPE. The second area of research was focused on the improvement of its barrier properties to fuels by the addition of lamellar charges known for their high aspect ratio inducing a tortuosity effect. The impact of these particles on sorption and extraction phenomena was also studied to determine an optimal HDPE-based formulation in order to limit the physical loss of oligomers and antioxidants. The guideline of this project was the determination of Structure / Morphology / Properties relationships to have a better understanding of the involved mechanisms

The simulation program GTperform is used to estimate the machine settings from performance measurements for the gas turbine model STG-800 at Siemens Industrial Turbomachinery in Finspång, Sweden. By evaluating different settings within the program, the engineers try to estimate the one that generatesthe performance measurement. This procedure is done manually at Siemens and is very time-consuming. This project aims to establish an algorithm that automatically establishes the correct machine setting from the performance measurements. Two algorithms were implemented in Python: Simulated Annealing and Gradient Descent. The algorithms analyzed two possible objective functions, and objective were tested on three gas turbines located at different locations. The first estimated the machine setting that generated the best fit to the performance measurements, while the second established the most likely solution for the machine setting from probability distributions. Multiple simulations have been run for the two algorithms and objective functions to evaluate the performances. Both algorithms successfully established satisfactory results for the second objective function. The Simulated Annealing, in particular, established solutions with a lower spread compared to Gradient Descent. The algorithms give a possibility to automatically establish the machine settings for the simulation program, reducing the work for the engineers.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18286号 / 工博第3878号 / 新制||工||1595(附属図書館) / 31144 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 木本 恒暢, 教授 白石 誠司, 准教授 浅野 卓 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18587号 / 工博第3948号 / 新制||工||1607(附属図書館) / 31487 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 北條 正樹, 教授 北村 隆行, 教授 琵琶 志朗 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第18698号 / エネ博第310号 / 新制||エネ||63(附属図書館) / 31631 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 教授 佐川 尚, 准教授 奥村 英之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19184号 / 工博第4061号 / 新制||工||1626(附属図書館) / 32176 / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 田畑 修, 教授 琵琶 志朗, 准教授 土屋 智由, 教授 松原 厚 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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