Reliability Theory of Structures with Strength Degradation in Load History

The theory of structural reliability is developed for repeated loads with due consideration for strength degradation dependent on the load intensity. The probability distribution of the residual strength of the structure is treated as such that modified by successive application of loads in the sense of both the non-failure effect and the strength-degradation effect. The numerical results of this study show some essential and interesting aspects as to the change in the structural strength and the reliability function through applications of repeated loads

Hysteresis Model of Structural Materials under Repeated Elasto-Plastic Deformation

This study has been attempted in order to simulate a plastic fatigue failure process and transition of hysteresis loops under a cyclic elasto-plastic deformation. The hysteresis model proposed herein consists of continuously distributed parallel elements. It can display the fatigue failure process of material which hardens in its initial stage, and deteriorates in the second stage unitil complete failure occurs. The numerical results based on the model are compared with the experimental results of a plastic bending fatigue test on SS 41 H-section steel beams

Random Fatigue Analysis of Structural Steel Bars Subjected to Plastic Bending

Low-cycle fatigue life of structural steel bars subjected to random plastic flexural deformation is analyzed. Fatigue tests are performed on 100×100 SS41 H bars under constant-amplitude and randomly varying repeated loads. Fatigue life for random loads is estimated by using the linear cumulative damage law. Damage per unit time (or cycle) is predicted by (1) the equivalent amplitude factor and (2) peak-trough and plastic deformation criteria. Estimated results are compared with test results

Purification and Crystallization of Oxygen-Evolving Photosystem II Core Complex from Thermophilic Cyanobacteria

This chapter describes the purification and crystallization of oxygen-evolving photosystem II core dimer complex from a thermophilic cyanobacterium Thermosynechococcus vulcanus. Procedures used for purification of photosystem II from the cyanobacterium involves cultivation of cells, isolation of thylakoid membranes, purification of crude and pure photosystem II core complexes by detergent solubilization, followed by differential centrifugation and column chromatography. The purified core dimer particles were successfully used for crystallization, and the methods and conditions used for crystallization are presented. These purification and crystallization procedures can be applied for another thermophilic cyanobacterium T. elongatus

Physiological characterization of a glacier living cyanobacterium, Phormidesmis priestleyi culture strain

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Correlation, Breit and Quantum Electrodynamics effects on energy level and transition properties of W54+^{54+} ion

The electron correlation effects and Breit interaction as well as Quantum Electro-Dynamics (QED) effects were expected to have important contribution to the energy level and transition properties of heavy highly charged ions. The ground states [Ne]$3s^{2}3p^{6}3d^{2}$ and first excited states [Ne]3s$^{2}3p^{5}3d^{3}$ of W$^{54+}$ ion have been studied by using Multi-Configuration Dirac-Fock method with the implementation of Grasp2K package. A restricted active space was employed to investigate the correlation contribution from different models. The Breit interaction and QED effects were taken into account in the relativistic configuration interaction calculation with the converged wavefunction. It is found that the correlation contribution from 3s and 3p orbital have important contribution to the energy level, transition wavelength and probability of the ground and the first excited state of W$^{54+}$ ion

SLOPT: Bandit Optimization Framework for Mutation-Based Fuzzing

Mutation-based fuzzing has become one of the most common vulnerability discovery solutions over the last decade. Fuzzing can be optimized when targeting specific programs, and given that, some studies have employed online optimization methods to do it automatically, i.e., tuning fuzzers for any given program in a program-agnostic manner. However, previous studies have neither fully explored mutation schemes suitable for online optimization methods, nor online optimization methods suitable for mutation schemes. In this study, we propose an optimization framework called SLOPT that encompasses both a bandit-friendly mutation scheme and mutation-scheme-friendly bandit algorithms. The advantage of SLOPT is that it can generally be incorporated into existing fuzzers, such as AFL and Honggfuzz. As a proof of concept, we implemented SLOPT-AFL++ by integrating SLOPT into AFL++ and showed that the program-agnostic optimization delivered by SLOPT enabled SLOPT-AFL++ to achieve higher code coverage than AFL++ in all of ten real-world FuzzBench programs. Moreover, we ran SLOPT-AFL++ against several real-world programs from OSS-Fuzz and successfully identified three previously unknown vulnerabilities, even though these programs have been fuzzed by AFL++ for a considerable number of CPU days on OSS-Fuzz.Comment: To appear in Proceedings of the 2022 Annual Computer Security Applications Conference (ACSAC '22