京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18181号 / 医博第3901号 / 新制||医||1004(附属図書館) / 31039 / 京都大学大学院医学研究科医学専攻 / (主査)教授 岩田 想, 教授 松田 道行, 教授 楠見 明弘 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

The sharing of data has become integral to advancing scientific research, but it introduces challenges related to safeguarding personally identifiable information (PII). This thesis addresses the specific problem of sharing drivers' face videos for transportation research while ensuring privacy protection. To tackle this issue, we leverage recent advancements in generative adversarial networks (GANs) and demonstrate their effectiveness in deidentifying individuals by swapping their faces with those of others. Extensive experimentation is conducted using a large-scale dataset from ORNL, enabling the quantification of errors associated with head movements, mouth movements, eye movements, and other human factors cues. Additionally, qualitative analysis using metrics such as PERCLOS (Percentage of Eye Closure) and human evaluators provide valuable insights into the quality and fidelity of the deidentified videos. To enhance privacy preservation, we propose the utilization of synthetic faces as substitutes for real faces. Moreover, we introduce practical guidelines, including the establishment of thresholds and spot checking, to incorporate human-in-the-loop validation, thereby improving the accuracy and reliability of the deidentification process. In addition to this, this thesis also presents mitigation strategies to effectively handle reidentification risks. By considering the potential exploitation of soft biometric identifiers or non-biometric cues, we highlight the importance of implementing comprehensive measures such as robust data user licenses and privacy protection protocols. / Master of Science / With the increasing availability of large-scale datasets in transportation engineering, ensuring the privacy and confidentiality of sensitive information has become a paramount concern. One specific area of concern is the protection of drivers' facial data captured by the National Driving Simulator (NDS) during research studies. The potential risks associated with the misuse or unauthorized access to such data necessitate the development of robust deidentification techniques. In this thesis, we propose a GAN-based framework for the deidentification of drivers' face videos while preserving important facial attribute information. The effectiveness of the proposed framework is evaluated through comprehensive experiments, considering various metrics related to human factors. The results demonstrate the capability of the framework to successfully deidentify face videos, enabling the safe sharing and analysis of valuable transportation research data. This research contributes to the field of transportation engineering by addressing the critical need for privacy protection while promoting data sharing and advancing human factors research.

The emergence of the Internet has sparked a tremendous explosion in the special class of systems called mission critical systems. These systems are so vital to their intended tasks that they must operate continuously. Two problems affect them: unplanned, and therefore disastrous, downtime and planned downtime for software maintenance. As the pressure to keep these systems operating continuously increases, scheduling downtime becomes complex. However, dynamically modifying the mission critical systems without disruption can reduce the need for a planned downtime. Every executing process has an executing code tightly coupled with an associated state, which continuously changes as the code executes. A dynamic modification at this juncture involves modifying the executable code and the state present within the binary image of the associated process. An ill-timed modification can create runtime incompatibilities that are hard to rectify and eventually cause a system crash. The purpose of the research in this thesis is to examine the causes for incompatibilities and propose the design of a dynamic modification technique: Software Hot Swapping. To achieve these objectives, the researcher proposes mechanisms which these incompatibilities can prevent, examines the characteristics and the implementation issues of such mechanisms, and demonstrates dynamic modification with a simple prototype Hot Swapping program. / Master of Science

A quantum state represents neither properties of a physical system nor anyone s knowledge of its properties. The important question is not what quantum states represent but how they are used as informational bridges. Knowing about some physical situations (its backing conditions), an agent may assign a quantum state to form expectations about other possible physical situations (its advice conditions). Quantum states are objective: only expectations based on correct state assignments are gen- erally reliable. If a quantum state represents anything, it is the objective probabilistic relations between its backing conditions and its advice con- ditions. This paper o¤ers an account of quantum states and their function

This research and development work deals with the design methodology for Cascaded Multilevel Converter (CMC) based Transmission STATCOM (TSTATCOM) and development of a &plusmn / 12MVAR, 12kV line-to-line wye-connected, 11-level CMC. This CMC module constitutes the basic building block of TSTATCOM systems. Sizing of the CMC module, number of H-Bridges in each phase of the CMC, AC voltage rating of the CMC, the number of paralleled CMC modules in the T-STATCOM system, optimum value of series filter reactors and determination of busbar in the power grid to which the T-STATCOM system is going to be connected are also discussed in the thesis in view of IEEE Std.519-1992, current status of HV IGBT technology and the required reactive power variation range for the T-STATCOM application. In the field prototype of the CMC module, the AC voltages are approximated to sinusoidal waves by Selective Harmonic Elimination Method (SHEM) and by the use of an optimized series input filter reactor. The use of n number of HBs in each phase provides us n number of freedom in the application of SHEM. One of them is allocated to the fundamental component while n-1 is for the elimination of low order harmonics. Since n is chosen to five in the prototype system, 5th, 7th,11th and 13th harmonic components are successfully eliminated in the AC voltage waveforms of the CMC module. The equalization of DC link capacitor voltages is achieved according to Modified Selective Swapping (MSS) algorithm. MSS is applied every 400&mu / s period if needed to obtain a perfect equalization of DC link capacitor voltages at the expense of higher switching frequency and hence switching losses. In this research work, an L-shaped laminated bus has been designed and the HV IGBT driver circuit has been modified for optimum switching performance of HV IGBT modules in each HB circuit. The performances of the HB circuit and the resulting 11-level CMC module have been obtained not only in the laboratory but also in the field. Design works for HB and the CMC are based on MATLAB and PSCAD simulations. The laboratory and field performance of the HB circuit and CMC module is found to be satisfactory and quite consistent with the theoretical results and design objectives. In addition to these, 154 kV, &plusmn / 50MVAr T-STATCOM prototype has been designed, implemented and installed at Sincan Transformer Substation-Ankara primarily for the purposes of reactive power compensation and terminal voltage regulation. The T-STATCOM prototype is composed of five parallel operated CMC modules developed within the scope of this PhD thesis research work. The T-STATCOM configuration permits the operation of any number of CMC modules in the range from one to five for experimental purposes. The performance of this T-STATCOM system is also presented in this PhD thesis as a sample application.

Rhomboids are unique membrane proteins that use a serine protease hydrolysis mechanism to cleave a transmembrane substrate within the lipid bilayer. This remarkable proteolytic activity is achieved by a core domain comprised of 6 transmembrane segments that form a hydrophilic cavity submerged in the membrane. In addition to this core domain, many rhomboids also possess aqueous domains of varying sizes at the N- and/or C-terminus, the sequences of which tend to be rhomboid-type specific. The functional role of these extramembranous domains is generally not well understood, although it is thought that they may be involved in regulation of rhomboid activity and specificity. While extramembranous domains may be important for rhomboid activity, they are absent in all x-ray crystal structures available. For this reason, we have focused on uncovering the structural and functional relationship between the rhomboid cytoplasmic domain and its catalytic transmembrane core. To investigate the structure and function of the bacterial rhomboid cytoplasmic domain, full-length rhomboids from Escherichia coli and Pseudomonas aeruginosa were studied using solution nuclear magnetic resonance (NMR) spectroscopy, mutation and activity assays. The P. aeruginosa rhomboid was purified in a range of membrane-mimetic media, evaluated for its functional status in vitro and investigated for its NMR spectroscopic properties. Results from this study suggested that an activity-modulating interaction might occur between the catalytic core transmembrane domain and the cytoplasmic domain. Further investigation of this hypothesis with the E. coli rhomboid revealed that protease activity relies on a short but critical sequence N-terminal to the first transmembrane segment. This sequence was found to have a direct impact on the rhomboid active site, and should be included in future structural studies of this catalytic domain. The structure of the cytoplasmic domain from the E. coli rhomboid was also determined by solution NMR. We found that it forms slowly-exchanging dimers through an exchange of secondary structure elements between subunits, commonly known as three-dimensional domain swapping. Beyond this rare example of domain swapping in a membrane protein extramembranous domain, we found that the rate of exchange between monomeric and dimeric states could be accelerated by transient interactions with large detergent micelles with a phosphocholine headgroup, but not by exposure to other weakly denaturing conditions. This novel example of micelle-catalyzed domain swapping interactions raises the possibility that domain swapping interactions might be induced by similar interactions in vivo. Overall, the results of this thesis have identified detergent conditions that preserve the highest level of activity for bacterial rhomboids, defined the minimal functional unit beyond what had been identified in available x-ray crystal structures, and characterized a novel micelle-catalyzed domain-swapping interaction by the cytoplasmic domain.

Rhomboids are unique membrane proteins that use a serine protease hydrolysis mechanism to cleave a transmembrane substrate within the lipid bilayer. This remarkable proteolytic activity is achieved by a core domain comprised of 6 transmembrane segments that form a hydrophilic cavity submerged in the membrane. In addition to this core domain, many rhomboids also possess aqueous domains of varying sizes at the N- and/or C-terminus, the sequences of which tend to be rhomboid-type specific. The functional role of these extramembranous domains is generally not well understood, although it is thought that they may be involved in regulation of rhomboid activity and specificity. While extramembranous domains may be important for rhomboid activity, they are absent in all x-ray crystal structures available. For this reason, we have focused on uncovering the structural and functional relationship between the rhomboid cytoplasmic domain and its catalytic transmembrane core. To investigate the structure and function of the bacterial rhomboid cytoplasmic domain, full-length rhomboids from Escherichia coli and Pseudomonas aeruginosa were studied using solution nuclear magnetic resonance (NMR) spectroscopy, mutation and activity assays. The P. aeruginosa rhomboid was purified in a range of membrane-mimetic media, evaluated for its functional status in vitro and investigated for its NMR spectroscopic properties. Results from this study suggested that an activity-modulating interaction might occur between the catalytic core transmembrane domain and the cytoplasmic domain. Further investigation of this hypothesis with the E. coli rhomboid revealed that protease activity relies on a short but critical sequence N-terminal to the first transmembrane segment. This sequence was found to have a direct impact on the rhomboid active site, and should be included in future structural studies of this catalytic domain. The structure of the cytoplasmic domain from the E. coli rhomboid was also determined by solution NMR. We found that it forms slowly-exchanging dimers through an exchange of secondary structure elements between subunits, commonly known as three-dimensional domain swapping. Beyond this rare example of domain swapping in a membrane protein extramembranous domain, we found that the rate of exchange between monomeric and dimeric states could be accelerated by transient interactions with large detergent micelles with a phosphocholine headgroup, but not by exposure to other weakly denaturing conditions. This novel example of micelle-catalyzed domain swapping interactions raises the possibility that domain swapping interactions might be induced by similar interactions in vivo. Overall, the results of this thesis have identified detergent conditions that preserve the highest level of activity for bacterial rhomboids, defined the minimal functional unit beyond what had been identified in available x-ray crystal structures, and characterized a novel micelle-catalyzed domain-swapping interaction by the cytoplasmic domain.

As the CMOS technology continues to scale into the deep sub-micron regime, the demand for higher frequencies and higher levels of integration poses a significant challenge for the clock generation and distribution design of microprocessors. Hence, skew optimization schemes are necessary to limit clock inaccuracies to a small fraction of the clock period. In this thesis, a crude deskew buffer (CDB) is designed to facilitate an adaptive deskewing scheme that reduces the clock skew in an ASIC clock network under manufacturing process, supply voltage, and temperature (PVT)variations. The crude deskew buffer adopts a DLL structure and functions on a 1GHz nominal clock frequency with an operating frequency range of 800MHz to 1.2GHz. An approximate 91.6ps phase resolution is achieved for all simulation conditions including various process corners and temperature variation. When the crude deskew buffer is applied to seven ASIC clock networks with each under various PVT variations, a maximum of 67.1% reduction in absolute maximum clock skew has been achieved. Furthermore, the maximum phase difference between all the clock signals in the seven networks have been reduced from 957.1ps to 311.9ps, a reduction of 67.4%. Overall, the CDB serves two important purposes in the proposed deskewing methodology: reducing the absolute maximum clock skew and synchronizes all the clock signals to a certain limit for the fine deskewing scheme. By generating various clock phases, the CDB can also be potentially useful in high speed debugging and testing where the clock duty cycle can be adjusted accordingly. Various positive and negative duty cycle values can be generated based on the phase resolution and the number of clock phases being “hot swapped”. For a 500ps duty cycle, the following values can be achieved for both the positive and negative duty cycle: 224ps, 316ps, 408ps, 592ps, 684ps, and 776ps.

As the CMOS technology continues to scale into the deep sub-micron regime, the demand for higher frequencies and higher levels of integration poses a significant challenge for the clock generation and distribution design of microprocessors. Hence, skew optimization schemes are necessary to limit clock inaccuracies to a small fraction of the clock period. In this thesis, a crude deskew buffer (CDB) is designed to facilitate an adaptive deskewing scheme that reduces the clock skew in an ASIC clock network under manufacturing process, supply voltage, and temperature (PVT)variations. The crude deskew buffer adopts a DLL structure and functions on a 1GHz nominal clock frequency with an operating frequency range of 800MHz to 1.2GHz. An approximate 91.6ps phase resolution is achieved for all simulation conditions including various process corners and temperature variation. When the crude deskew buffer is applied to seven ASIC clock networks with each under various PVT variations, a maximum of 67.1% reduction in absolute maximum clock skew has been achieved. Furthermore, the maximum phase difference between all the clock signals in the seven networks have been reduced from 957.1ps to 311.9ps, a reduction of 67.4%. Overall, the CDB serves two important purposes in the proposed deskewing methodology: reducing the absolute maximum clock skew and synchronizes all the clock signals to a certain limit for the fine deskewing scheme. By generating various clock phases, the CDB can also be potentially useful in high speed debugging and testing where the clock duty cycle can be adjusted accordingly. Various positive and negative duty cycle values can be generated based on the phase resolution and the number of clock phases being “hot swapped”. For a 500ps duty cycle, the following values can be achieved for both the positive and negative duty cycle: 224ps, 316ps, 408ps, 592ps, 684ps, and 776ps.

In this thesis, we studied a component-based software design for componentizing Linux kernel. Our goal is to componentize kernel modules and explicitly define the dependency relation of components in the kernel. Componentization can greatly improve composability, evolvability, extensibility and testability of a software system, and can thus increase the productivity of software development and reduce the cost of maintenance. On top of the componentized kernel, we developed a suite of tools to facilitate the operations on kernel components. In the component-based design, the basic software unit is a component. We envision any subsystem in kernel as a composition of components. To realize the concept, we explicitly create the output ports by augmenting the symbol table of a kernel module to record the relocation information, i.e., the locations where the module invokes the functions exported by other modules. We developed tools to discover the data passing among components such that the dependency relation among components can be clearly disclosed. With componentization in place, we are able to implement the hot-swapping technique which allows the system structure to be dynamically changed at run time. The technique makes it possible to test, swap or re-compose components when part of the system cannot be terminated or removed. The proposed system is implemented on Linux kernel 2.6.17.1. While our componentization does not introduce any time overhead when modules are in action, we evaluated our approach in terms of module loading time, memory consumption and hot-swapping time. We found that the module loading time and memory consumption of a componentized module are both proportional to the number of relocations in the module. The hot-swapping time is related to the position of the symbol to be swapped in the symbol table. All these suggest that we still have room to improve the way we realized the componentization in Linux kernel.