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20 results on '"Zhang, Jingshi"'

3. Joint Cyber Risk Assessment of Network Systems with Heterogeneous Components

Author

Da, Gaofeng, Xu, Maochao, Zhang, Jingshi, and Zhao, Peng

Subjects
Computer Science - Social and Information Networks, Mathematics - Probability
Abstract

Cyber risks are the most common risks encountered by a modern network system. However, it is significantly difficult to assess the joint cyber risk owing to the network topology, risk propagation, and heterogeneities of components. In this paper, we propose a novel backward elimination approach for computing the joint cyber risk encountered by different types of components in a network system; moreover, explicit formulas are also presented. Certain specific network topologies including complete, star, and complete bi-partite topologies are studied. The effects of propagation depth and compromise probabilities on the joint cyber risk are analyzed using stochastic comparisons. The variances and correlations of cyber risks are examined by a simulation experiment. It was discovered that both variances and correlations change rapidly when the propagation depth increases from its initial value. Further, numerical examples are also presented.

Published
2020

16. The high-level expression of nm23(NDP) gene in NPC

Author

Lu Lili, Xie Zuo-fu, Zhang Jingshi, Zheng Tian-rong, and Lin Xian-dong

Subjects
Cancer Research, medicine.medical_specialty, biology, Cell, medicine.disease, Molecular biology, medicine.anatomical_structure, Endocrinology, Oncology, Nasopharyngeal carcinoma, Internal medicine, Medicine public health, medicine, biology.protein, Carcinoma, Stage (cooking), Antibody, High level expression, Gene
Abstract

We have studied the expression of nm23(NDP) in 50 cases nasopharyngeal biopsies with anti-nm23(NDP) antibodies. As a result, the NDP positive rate in nasopbaryngeal carcinoma (NPC) (95.54%) markedly increased (P

Published
1996

18. Study of Formation and Development of Lubricant Bridge in Head–Disk Interface Using Molecular Dynamic Method.

Author

Dai, Xiangyu, Zhang, Jingshi, Shen, Shengnan, Li, Hui, Zhai, Tianqi, Wu, Shijin, Liu, Sheng, and Du, Hejun

Subjects
*MOLECULAR interactions, *HARD disks, *DENSITY functional theory, *MOLECULAR physics, *SYNTHETIC lubricants
Abstract

The lubricant bridge connecting the slider and the disk will significantly deteriorate the read–write stability of the hard disk drive. This paper builds a model of disk-lubricant-slider system. The coarse-grained bead-spring model is used to represent perfluoropolyethers molecules. And the molecular dynamic method is used to study the formation time and the molecule number of the lubricant bridge under different disk rotation speeds and slider flying heights. Furthermore, the influence of lubricant bridge on the pressure acting on the slider pad is also studied. [ABSTRACT FROM AUTHOR]

Published
2017
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19. Effects of Arm Swing on Particle Trajectories in HDD Using the CFD Dynamic Mesh Method.

Author

Zhang, Guoqing, Zhai, Tianqi, Li, Hui, Shen, Shengnan, Wu, Shijing, Zhang, Jingshi, and Liu, Sheng

Subjects
PARTICLE tracks (Nuclear physics), HARD disks, ACTUATORS, COMPUTATIONAL fluid dynamics, GIMBALS (Mechanical devices), SPHERICAL motion
Abstract

Previous works investigated particle trajectories in hard disk drives (HDDs) with the actuator arm and the head gimbals assembly at a fixed position. Actually, internal fluid field characteristics of HDDs can be greatly changed by the arm swing during track-seeking operations, which can affect particle trajectories and trapping status. In this paper, using the dynamic mesh method in a 2.5 in HDD for the first time considers the arm swing in the computational fluid dynamics (CFD) simulation. Al2O3 particle trajectories in this HDD are studied by the CFD solver FLUENT with user-defined functions. The trapping criterion for Al2O3 particles is used as a boundary condition for colliding surfaces. Simulation results reveal that the particle undergoes a larger number of collisions with the disk surface for the average seek time of 12 ms than for the average seek time of 6 ms. In addition, the faster the arm swings, the larger the number of particles that gather near the arm, and the shorter time it will take for particles to be trapped. Moreover, particle-surface collisions can successively take place many times in the helium flow. Furthermore, the particles are trapped slower in the helium-filled drive than in the air-filled drive. [ABSTRACT FROM AUTHOR]

Published
2017
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20. Differences in the structure and magnetic properties of Sr1− x RE x Fe12O19 (RE: Pr and Dy) ferrites by microwave-assisted synthesis method.

Author

Zhou, Zhipeng, Wang, Zhanyong, Wang, Xiuting, Wang, Xiaorui, Zhang, Jingshi, Dou, Fengkai, Jin, Minglin, and Xu, Jiayue

Subjects
*IRON oxides, *MICROWAVE spectroscopy, *SOLUBILITY, *METAL microstructure, *MAGNETIC properties of metals
Abstract

Highlights: [•] The highest coercivity is achieved for excellent exchange coupling interaction. [•] Great differences between RE are contributed to their saturated solubility. [ABSTRACT FROM AUTHOR]

Published
2014
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