電力ミックスの多様性における突発的途絶を基とした動的脆弱性に関する研究

京都大学0048新制・課程博士博士(エネルギー科学)甲第22793号エネ博第407号新制||エネ||78(附属図書館)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 宇根﨑 博信, 教授 石原 慶一, 教授 黒崎 健学位規則第4条第1項該当Doctor of Energy ScienceKyoto UniversityDFA

Hysteretic-Viscous Hybrid Damper System With Stopper Mechanism for Tall Buildings Under Earthquake Ground Motions of Extremely Large Amplitude

This paper is aimed at proposing a hysteretic-viscous hybrid (HVH) damper system for tall buildings subjected to long-period pulse-type earthquake ground motions of extremely large amplitudes. The HVH system was introduced for a single-degree-of-freedom (SDOF) system in the recent paper (Hashizume and Takewaki, 2020). The HVH system consists of a large-stroke viscous damper and a hysteretic damper with a gap mechanism as a stopper for mitigating catastrophic damage. In the present paper, the effectiveness of the HVH system is shown for tall buildings. Pulse-type earthquake ground motions of an extremely large amplitude have been recorded in the past (for example Northridge 1994 and Kumamoto 2016). These ground motions risk causing catastrophic damage to high-rise and base-isolated buildings with a long natural period. A double impulse is used here as a substitute for pulse-type ground motions of an extremely large amplitude. Time-history response analyses are performed for an amplitude-modulated critical double impulse to reveal the effectiveness of the proposed HVH system. In addition, double impulse pushover (DIP) analysis, which was proposed by Akehashi and Takewaki (2019), is conducted to reveal the critical resonant performance of elastic-plastic tall buildings together with the analysis for recorded ground motion at Kumamoto (2016). A comparison with the dual hysteretic damper (DHD) system composed of parallel-type small- and large-amplitude hysteretic dampers is also conducted to investigate the seismic performance of the proposed HVH system

Awareneness, Acceptance And Perception Of Malaysia's Vision 2020 Challenges Among University Staff Member

Two-hundred and twenty-two questionnaires were distributed to all university staff members (those in the professional and managerial groups) of Universiti Teknologi Malaysia and Universiti Utara Malaysia to examine: (i) their level of awareness and acceptance of Malaysia’s Vision 2020 Challenges and how they perceived the difficulties in overcoming the Challenges; (ii) the relationship between their awareness and acceptance of, and their perception of difficulties in meeting the Challenges; and (iii) the influence of socio-demographic features of gender, age, work site and work setting assignment on their acceptance of and their perception of difficulties in overcoming the Challenges. Staff member’s responses were measured using a fivepoint Likert-type scale. The returned questionnaires, 145 of them, were analyzed using the Pearson Correlation, t-Test and ANOVA to determine any significant relationship and differences among the 10 hypotheses at the .05 level of significance. The findings revealed that: (i) there was a positive significant relationship between staff awareness and staff acceptance of the nine Challenges of Malaysia’s Vision 2020. This indicated the staffs’ awareness of the Challenges had some degree of influence in their acceptance of the Challenges; (ii) there was a relationship between staff awareness of the Challenges and their perception of the difficulties in overcoming the Challenges, at a slight correlation or negligible relationship; and (iii) there was a significant mean difference in the staffs’ perception of the difficulties in overcoming the Challenges according to the work sites. The results indicated that there were no significant mean differences in the staffs’ acceptance of the Challenges according to their demographic features of gender, age, work site, and work setting assignment; and there were no significant mean differences in the staffs’ perception of the difficulties in overcoming the Challenges according to gender, age and work assignment. Staff are aware of the nine central strategic Challenges they must face in realizing the Vision. Among these nine, staff were most aware of Challenge 2--Creating a developed Malaysian society, while Challenge 5--Establishing a mature, liberal and tolerant society , appeared to be the most accepted Challenge. Challenge 8--Ensuring an economically just society, was perceived as the most difficult Challenge to overcome. In addition, the staff were 68 percent confident that the nine Challenges could be overcome. The findings indicated the Vision is accepted and has been well communicated. Programs and actions related to the role of the universities in assisting the nation to realise the Vision were discussed

Hysteretic–Viscous Hybrid Damper System for Long-Period Pulse-Type Earthquake Ground Motions of Large Amplitude

This paper aims to develop a hysteretic–viscous hybrid (HVH) damper system for long-period pulse-type earthquake ground motions of large amplitude. Long-period pulse-type earthquake ground motions of large amplitude have been recorded recently (Northridge, 1994; Kumamoto, 2016). It is well-known that these ground motions could cause severe damage to high-rise and base-isolated buildings with long natural period. To mitigate the damage caused by such ground motion, a new viscous–hysteretic hybrid damper system is proposed here, which consists of a viscous damper with large stroke and a hysteretic damper including a gap mechanism. A double impulse is employed as a representative of long-period pulse-type earthquake ground motions of large amplitude and a closed-form maximum response to this double impulse is derived for an elastic–plastic SDOF system including the proposed HVH system. To reveal the effectiveness of the proposed HVH system, time-history response analyses are performed for an amplitude modulated double impulse and a recorded ground motion at Kumamoto (2016). The performance comparison with the previous dual hysteretic damper (DHD) system consisting of small-amplitude and large-amplitude hysteretic dampers in parallel is also conducted to investigate the effectiveness of the proposed HVH system

Λ\Lambda-Split: A Privacy-Preserving Split Computing Framework for Cloud-Powered Generative AI

In the wake of the burgeoning expansion of generative artificial intelligence (AI) services, the computational demands inherent to these technologies frequently necessitate cloud-powered computational offloading, particularly for resource-constrained mobile devices. These services commonly employ prompts to steer the generative process, and both the prompts and the resultant content, such as text and images, may harbor privacy-sensitive or confidential information, thereby elevating security and privacy risks. To mitigate these concerns, we introduce $\Lambda$-Split, a split computing framework to facilitate computational offloading while simultaneously fortifying data privacy against risks such as eavesdropping and unauthorized access. In $\Lambda$-Split, a generative model, usually a deep neural network (DNN), is partitioned into three sub-models and distributed across the user's local device and a cloud server: the input-side and output-side sub-models are allocated to the local, while the intermediate, computationally-intensive sub-model resides on the cloud server. This architecture ensures that only the hidden layer outputs are transmitted, thereby preventing the external transmission of privacy-sensitive raw input and output data. Given the black-box nature of DNNs, estimating the original input or output from intercepted hidden layer outputs poses a significant challenge for malicious eavesdroppers. Moreover, $\Lambda$-Split is orthogonal to traditional encryption-based security mechanisms, offering enhanced security when deployed in conjunction. We empirically validate the efficacy of the $\Lambda$-Split framework using Llama 2 and Stable Diffusion XL, representative large language and diffusion models developed by Meta and Stability AI, respectively. Our $\Lambda$-Split implementation is publicly accessible at https://github.com/nishio-laboratory/lambda_split.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Eigenstate Thermalization in Long-Range Interacting Systems

Motivated by recent ion experiments on tunable long-range interacting quantum systems [B.Neyenhuis et al., Sci.Adv.3, e1700672 (2017, https://doi.org/10.1126/sciadv.1700672 )], we test the strong eigenstate thermalization hypothesis (ETH) for systems with power-law interactions $\sim 1/r^{\alpha}$. We numerically demonstrate that the strong ETH typically holds at least for systems with $\alpha\geq 0.6$, which include Coulomb, monopole-dipole, and dipole-dipole interactions. Compared with short-range interacting systems, the eigenstate expectation value of a generic local observable is shown to deviate significantly from its microcanonical ensemble average for long-range interacting systems. We find that Srednicki's ansatz breaks down for $\alpha \lesssim 1.0$ at least for relatively large system sizes.Comment: 7 pages, 4 figures, supplemental material with 22 pages and 13 figures. The readability of the manuscript (especially the setup section)is improved. Hyperlinks are embedde

Eigenstate Thermalisation Hypothesis for Translation Invariant Spin Systems

We prove the Eigenstate Thermalisation Hypothesis (ETH) for local observables in a typical translation invariant system of quantum spins with mean field interaction. This mathematically verifies the observation made in [L.Santos and M.Rigol, Phys.Rev.E 82, 031130 (2010, https://journals.aps.org/pre/abstract/10.1103/PhysRevE.82.031130)] that ETH may hold for systems with additional translation symmetries for a naturally restricted class of observables. We also present numerical support for the same phenomenon for Hamiltonians with local interactions.Comment: 23 pages, 2 figure