京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20881号 / 理博第4333号 / 新制||理||1622(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)准教授 梅田 亨, 教授 上 正明, 教授 雪江 明彦 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

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With the advancement of wireless communication systems, the demand for higher data rates is increasing exponentially. Non Orthogonal Multiple Access (NOMA) is expected to play an important role in 5G new radio networks. In contrast to conventional multiple access schemes, NOMA allows different users to efficiently share the same resources (i.e., time, frequency and code) at different power levels so that the user with lower channel gain is served with a higher power and vice versa. Multiple Input Multiple Output (MIMO) technology to support multiple users, employ tens or even hundreds of antennas at the base station which increases throughput and spectrum efficiency. The combination of NOMA and MIMO techniques can achieve significant performance gains and provide better wireless services to cope with the demands of massive connectivity. In this thesis, we analyze the performance of NOMA-MIMO system. We derive analytical expressions for the performance metrics like Outage Probability (OP) and Symbol Error Rate (SER) in power domain of NOMA-MIMO communication system. The numerical results are validated with the simulation results in MATLAB and the influencing factors for better performance of the system are analysed.

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Tropical cyclone (TC) intensity and structure are affected by their environments, including sea surface temperature, vertical wind shear, and atmospheric moisture. Analyses of TC environments often rely on area-averaged quantities, yet the spatial variability of these fields can affect TC behavior, such as moisture distribution impacting where and how much rain falls. This study identifies spatial patterns of environmental moisture surrounding mature North Atlantic TCs during 2000-2021 in shear of less than 20 knots. Empirical orthogonal function analysis of total column water vapor reveals six dominant patterns. These patterns account for nearly 67% of the variance in the dataset and are affected by geographic location and large-scale atmospheric phenomena. Mid-level ventilation appears more likely in certain patterns. Future work will explore radar and passive microwave observations for cases in each pattern to quantify the physical impacts of these moisture patterns on mature TCs.

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The material removal process uses cutting tools in order to produce the desired shape of the workpiece. Tool wear has been a problem for cutting tools, since cutting tools wear and break. Research has been accomplished in the tool wear field for tool life and more recently tool wear. The computer generation has created a method to simulate the material removal process. These computer simulations model the cutting tool reaction with the workpiece. Many of the simulation models use finite element analysis to calculate the reaction of the cutting tool. Different finite element models are being used throughout the world for research. This thesis used an updated Lagrangian model in conjunction with Archard's law to predict the wear of the cutting tool. This research used experimental data to correlate with simulation data to see whether or not Archard's law was a good approximation for tool wear. The research used different side rake angles and cutting surface speed to test the simulation. Shear angle, contact length, cutting ratio, and force are used to provide output values to compare the experimental and computer simulation data. The comparative results showed good trends between the experimental and computer simulation data in every comparison. The results also showed a good approximation for the force and contact length values. Archard's law can be used to model wear on cutting tools with further research.

We solve RLL-relation with fundamental orthogonal/symplectic R-matrix examining polynomial with respect to u expressions for L-operator. We use creation-annihilation operators to construct a realization of Yangian generators.

Joel Mondo Kisekini, for the Master of Science degree in Civil Engineering, presented on March 25, 2022, at Southern Illinois University Carbondale.TITLE: EFFECT OF SIMULTANEOUS APPLICATION OF THE TWO HORIZONTAL ORTHOGONAL GROUND MOTION COMPONENTS ON THE SEISMIC BEHAVIOR OF BUILDINGSMAJOR PROFESSOR: Dr. JALE TEZCAN During an earthquake, buildings are simultaneously excited by two horizontal and one vertical ground motion components. Modern seismic codes and guidelines such as ASCE/SEI 41-06 (Seismic rehabilitation of existing buildings, American Society of Civil Engineers), EUROCODE 8 (1998-1) (Design provisions for earthquake resistance of structures, European Committee for Standardization, 2003), FEMA 356 (Prestandard and Commentary for Seismic Rehabilitation of the Buildings) and FEMA P-2082 (NEHRP Recommended Seismic Provisions for new buildings and other structures) require the consideration of the effects of two horizontal orthogonal ground motions in seismic design of buildings. Therefore, the main objective of this study is to evaluate the simultaneous effect of two horizontal orthogonal ground motion components to seismic behavior of buildings. A four-story steel frame is modeled, and it is subjected to a set of twenty ground motion pairs recorded distances between x and y kilometer from epicenter. Three methods for combining peak response to individual component of ground motions is used to estimate the displacement responses. The combination rules used in this present study are 30%, SRSS, and 20%. The response of the four-story steel frame is investigated within the context of linear response history analysis and the results are compared to the peak responses obtained from time history analyses under bidirectional and unidirectional ground motion. The structural response includes the following parameters: nodal displacements and the critical angle of excitation. The output results showed that the maximum response under two components was, on average, 23 % more than the maximum response under a single component, and the two horizontal orthogonal seismic excitations increased the structure displacement response compared to unidirectional excitation.

In 1939, I.M. Sheffer proved that every polynomial sequence belongs to one and only one type. Sheffer extensively developed properties of the B-Type 0 polynomial sequences and determined which sets are also orthogonal. He subsequently generalized his classification method to the case of arbitrary B-Type k by constructing the generalized generating function A(t)exp[xH1(t) + · · · + xk+1Hk(t)] = ∑∞n=0 Pn(x)tn, with Hi(t) = hi,iti + hi,i+1t i+1 + · · · , h1,1 ≠ 0. Although extensive research has been done on characterizing polynomial sequences, no analysis has yet been completed on sets of type one or higher (k ≥ 1). We present a preliminary analysis of a special case of the B-Type 1 (k = 1) class, which is an extension of the B-Type 0 class, in order to determine which sets, if any, are also orthogonal sets. Lastly, we consider an extension of this research and comment on future considerations. In this work the utilization of computer algebra packages is indispensable, as computational difficulties arise in the B-Type 1 class that are unlike those in the B-Type 0 class.