京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18183号 / 医博第3903号 / 新制||医||1004(附属図書館) / 31041 / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邉 大, 教授 髙橋 良輔, 教授 髙橋 淳, 教授 江藤 浩之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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In a world with high energy cost, the efficiency of motors becomes increasingly important. Thereby, the understanding of loss mechanics is of great significance and having accurate simulation models for the efficiency of motors is crucial.    Bosch Rexroth Mellansel has developed a new radial piston hydraulic motor with high power, capable of operating at high torque and speed. In this master thesis the newly developed motor will be examined and undergo a lab test to determine its efficiency. The results from this will then be used to improve the current simulation model and aim for a physical model that align with the efficiency results. Furthermore, the loss mechanics of the motor is important and will be studied during this thesis. The loss mechanics in a motor can be split into two parts, hydro-mechanical and volumetric losses. Hydro-mechanical losses refer to the losses due to both friction and hydraulic flow. The losses in the fluid flow are in turn divided into two parts, the major losses and the minor losses which are the friction losses in the fluid and the losses due to geometric changes in the channels respectively. The volumetric losses are on the other hand the losses from internal and external leakage of the hydraulic fluid, and compression flow which is the extra flow that occurs when the fluid changes density.  In order to determine efficiency values from a radial piston hydraulic motor, a test specification was written containing the information needed to perform the test, including two different methods, the pressure and torque method, and the sensors needed to measure the different parameters. For the hydro-mechanical efficiency the uncertainty is 0.1% for the pressure method and 0.15% for the torque method. The test was performed for several different rotational speeds and different pressure points. An improved model was developed from the test results by testing and optimization, and it was found that having the losses due to geometric changes in the channels, depend on Reynolds number agreed better with the test result. However, the improved simulation model does not align as well with the test result for all measured points. Hence a further investigation on the friction model and the dependence on pressure might improve the model further. However, it was found that for a specific sub test, the new model had a mean difference from the pressure method test result of 10^-3. While the mean difference for the unaltered simulation model was 10^-2, hence the new simulation model is an improvement. Therefore, the outcome of this master thesis is an improved simulation model for the newly developed radial piston hydraulic motor QMp 560-560 but also for future motors to come.

In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of McMaster University's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink. / The need for reductions in global greenhouse gas emissions, coupled with rising fuel prices, has motivated intense research in the area of hybrid and fully electric crafts for commercial applications in the aviation sector. This thesis explores implementation of Halbach arrays in high-speed radial flux machines (RFMs) and low-speed axial flux machines (AFMs) for aerospace applications. Highly accurate analytical equations are developed for quickly predicting the magnetic field in the latter (both for coreless and steel core stators) due to the complex three dimensional axial flux paths which make traditional finite element analysis time-consuming. Electromagnetic design and optimization of two aerospace machines that use Halbachs are detailed. The first is a ~14 kW AFM intended to replace an existing high lift motor RFM concept in NASA’s Maxwell X57 all-electric plane. Two design variants are selected which achieve a 10 % increase in torque/power and a 10 % decrease in mass/volume, respectively. The second machine is a 20,000 RPM surface permanent magnet RFM capable of 150 kW peak power output that is intended as a proof-of-concept for the later development of a megawatt machine for a hybrid and/or all-electric aircraft. / Thesis / Master of Applied Science (MASc)

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Calves are born agammaglobulinemic and rely on colostrum consumption for the transfer of maternal passive immunity. Calves that fail to absorb adequate amounts of maternal antibodies from colostrum are commonly referred to as having failed transfer of passive immunity (FTPI). The overall aim of this dissertation was to explore the usefulness of FTPI testing in neonatal beef calves to predict their risk for subsequent illness or death. The objectives were to evaluate the impact of FTPI on pre-weaning disease in beef and dairy calves, quantify and compare the variance in IgG concentrations measured by radial immunodiffusion and serum total protein (STP) values measured by optical refractometry, and evaluate the correlation between herd-level prevalence of FTPI and herd-level prevalence of pre-weaning disease in beef calves. Evaluation of literature relevant to FTPI was compiled and assessed to quantify the impact of FTPI on pre-weaning disease in beef and dairy calves. A series of randomized trials were used to evaluate the variance in IgG concentrations and STP values from banked serum. Health records from multiple farms and IgG results were used to evaluate the relationship between FTPI and disease at the individual and herd-level. Failed transfer of passive immunity had a variable association with pre-weaning disease in beef and dairy calves. IgG concentrations were less precise than STP values especially when dilution was required. IgG concentrations and STP values were associated with an increased risk of disease in pre-weaned beef calves, but FTPI cut-off values poorly classified the risk for subsequent disease. The proportion of calves with FTPI was not correlated with the proportion of calves that developed pre-weaning disease. Using a single immunological factor, such as IgG concentration or STP, to predict disease results in the misclassification of disease risk and does not consider additional component causes of disease.

Metalearning aims to obtain knowledge of the relationship between the mechanism of learning and the concrete contexts in which that mechanisms is applicable. As new mechanisms of learning are continually added to the pool of learning algorithms, the chances of encountering behavior similarity among algorithms are increased. Understanding the relationships among algorithms and the interactions between algorithms and tasks help to narrow down the space of algorithms to search for a given learning task. In addition, this process helps to disclose factors contributing to the similar behavior of different algorithms. We first study general characteristics of learning tasks and their correlation with the performance of algorithms, isolating two metafeatures whose values are fairly distinguishable between easy and hard tasks. We then devise a new metafeature that measures the difficulty of a learning task that is independent of the performance of learning algorithms on it. Building on these preliminary results, we then investigate more formally how we might measure the behavior of algorithms at a ner grained level than a simple dichotomy between easy and hard tasks. We prove that, among all many possible candidates, the Classifi er Output Difference (COD) measure is the only one possessing the properties of a metric necessary for further use in our proposed behavior-based clustering of learning algorithms. Finally, we cluster 21 algorithms based on COD and show the value of the clustering in 1) highlighting interesting behavior similarity among algorithms, which leads us to a thorough comparison of Naive Bayes and Radial Basis Function Network learning, and 2) designing more accurate algorithm selection models, by predicting clusters rather than individual algorithms.

Axisymmetric radial Bernstein modes are known to exist in non-neutral plasmas and have been studied theoretically and computationally in 1D, but detection of these modes has still proven to be difficult due to self-shielding. To help advance the work on this front we created a 2D particle-in-cell (PIC) code that simulates a non-neutral plasma in a Malmberg-Penning trap. A detailed description of the PIC code itself has been included that highlights the benefits of using an $r^2$--$z$ grid and how it can be tested. The focus of the PIC simulation was to discover how best to drive and detect these modes. While it is improbable that radial Bernstein modes will be detected in long plasmas, we show that it may be a possible due to the axial nodal structure in the potential and electric field generated by confining plasmas of any finite-length. Additionally, we find that for a short plasma the strongest detection signal along the trap wall occurs at the plasma's midpoint rather than near the ends. Results show that oscillating the confinement potentials is sufficient to excite the fundamental radial Bernstein mode, but not any of the higher order modes. The higher order modes can be seen in the simulation, however, by sinusoidally driving the radial electric field. Unfortunately, the individual modes are difficult to isolate which we suspect is due to mode mixing. Finally, we report frequencies and mode shapes for the fundamental mode and the (lower) first higher order mode.

If unaccounted for, differences in human anatomy can lead to adverse clinical outcomes for patients. The literature describes numerous variations of branches of the brachial artery; the most common anomaly is found as high as 25% of the time, in which the brachial artery passes over the median nerve, splitting the brachial artery into superficial and deep branches. Another common variation of the forearm arterial supply includes branching of the radial artery from the brachial artery proximal to the antecubital fossa (12.5%). Herein, we report a unique variation found in a 96-year-old white whole-body formalin-fixed male donor, dissected with typical dissection techniques. Although predictably bifurcating at the cubital fossa, the relative calibers and distribution of the ulnar and radial arteries in the forearm were notably atypical. The common interosseous artery branched from the radial artery rather than the ulnar artery, and distally branched into the anterior and posterior interosseous arteries. This morphology resulted in the deep anterior forearm and entirety of the posterior forearm relying on the radial artery for perfusion. There was also a notable size difference between the ulnar and radial arteries in which the radial artery was much larger. A review of the literature revealed two articles reporting this unique anomaly. It is important clinically to understand this abnormal branching pattern, as various medical procedures involve the radial artery. The radial artery is commonly used to gain access to circulation for cardiac catheterization and stent placement and can also be accessed for cannulation for a variety of medical procedures. Awareness of radial artery dominance reduces the possibility of iatrogenic injury and increases positive clinical outcomes. This protocol was reviewed by the VCOM IRB (#2022-050).