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Mode-dependent H∞ Filtering for Time-varying Delays Neutral Jump Systems Based on FWM Technique
Guowei Zhao,Guangming Zhuang,Jianwei Xia,Wei Sun,Junsheng Zhao,Minsong Zhang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.6
This paper is concerned with the problem of mode dependent H∞ filter for uncertainty Markovian jump system with neutral delay and retarded time-varying delay. By using free weight matrix (FWM) technique, the stability conditions of delay dependent are obtained under the framework of Lyapunov stability theory. Based on those result, the delay dependent conditions for full order and mode dependent Markovian jump linear filters are gained, which are expressed by Linear matrix inequalities (LMIs). Finally, a numerical example and a PEEC practical example are employed to prove the validity of the results.
Zhao Linjie,Yang Mao,Xiao Chengjian,Gong Yu,Ran Guangming,Chen Xiaojun,Li Jiamao,Yue Lei,Chen Chao,Hou Jingwei,Wang Heyi,Long Xinggui,Peng Shuming 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1
Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li4SiO4 pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li4SiO4 made by melt spraying method at 467 ◦C is approximately 23.34 h. High-density Li4SiO4 pebbles exhibit tritium release at relatively low temperatures (<600 ◦C) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ◦C and 550 ◦C is 1.19 × 10 11 cm2/s and 5.34 × 10 11 cm2/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.
Failure Mechanisms of Graded Ceramic Tool in Ultra High Speed Dry Milling of Inconel 718
Guangming Zheng,Jun Zhao,Anhai Li,Xiaobin Cui,Yonghui Zhou 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.
A graded ceramic tool material was fabricated by hot-pressing. Its cutting performance and failure mechanisms were investigated in dry face milling of Inconel 718 using round inserts at ultra high speeds ranging from 500 to 1600 m/min. The results showed that the microscopic chip shape was serrated type and the minimal cutting force was obtained at 900 m/min under this ultra high speed cutting conditions. Due to the enhanced mechanical properties and higher fracture resistance, the graded tool showed a selfsharpening characteristic. And the notch wear resistance of the graded tool was higher than that of the common reference tool under the same cutting condition. The failure mechanisms involved chipping, flaking, abrasive wear and adhesive wear. The mechanisms responsible for the higher cutting performance of the graded tool were determined to be the higher mechanical properties. The understanding of the failure mechanisms in ultra high speed milling processes can provide the guidance for the proper application of the tools, furthermore the guidance for tool materials design.
Stiffness effects on repeatability of positioning of linear axes
Guangming Sun,Yimiao Wang,Wenjin Wang,Jinjun Liu,Ming Yu,Jian Zhao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9
This paper studies the effect of stiffness (including slider stiffness and bearing stiffness) on the repeatability of the positioning of linear axes. First, a mathematical model between stiffness and the repeatability of the positioning of linear axes is established. The effects of the stiffness of the slider and bearing on the repeatability of positioning are analysed. The theoretical results show that the repeatability of the positioning decreases as the slider component stiffness and bearing stiffness increases. Second, a finite element analysis is implemented to calculate the effect of slider stiffness on the repeatability of positioning, the simulation results are found to be consistent with the theoretical results. Finally, the effect of bearing stiffness on the repeatability of positioning is experimentally investigated. The experimental and theoretical analysis results have been observed to coincide. Thus, the accuracy of the theoretical analysis is verified by both simulation and experimental results. The derived results afford designers and engineers a scientific basis for the stiffness design theory.
Zhao Liang,Hao Ding,Guangming Wang,Xiaohui Zhang 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.2
In order to explore the optimal spraying effect of diff erent electrostatic spraying parameters on droplet deposition on the back of target, the application height, angle, charging voltage, and nozzle water pressure had been applied as spraying variables for the test designed to investigate on droplet density, deposition and coverage in diff erent depth areas of the target. The results of the study showed that the height and angle of the spatial parameters of the application had a significant effect on the application effect. The droplet deposition effect decreased by 94.71%, 89.09% and 94.17% at diff erent depths on the back of the target as the height increased from 20 to 50 cm. The deposition effects of droplets at diff erent depths on the back of the target at 60° tilt angle are 5.91%, 9.81% and 51.97% of them at 0° tilt angle respectively. The results of orthogonal experiment showed that the optimal parameters of diff erent depth areas on the back of different targets were inconsistent. The height and angle of application are the main influencing factors, when the target is warped up. The depth range of the target (5–7.5 cm) is greatly affected by the nozzle water pressure. In the actual spraying pesticides application, the appropriate operating parameters can be selected according to the size and attitude of the leaf surface to improve the spraying effect.
Yuqian Lin,Guangming Zhuang,Jianwei Xia,Wei Sun,Junsheng Zhao 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.3
In this paper, the problem of asynchronous robust H∞ dynamic output feedback control for Markovian jump neural networks with norm-bounded parameter uncertainties and mode-dependent time-varying delays is investigated. The improved delay-dependent stochastic stability conditions and bounded real lemma are obtained by introducing the relaxation variables, which reduces the conservatism caused by boundary technology and model transformation. An improved Lyapunov-Krasovskii functional is constructed using linear matrix inequalities. On this basis, the solution of robust H∞ dynamic output feedback problem and sufficient conditions for solving the problem of asynchronous dynamic output feedback controller are given respectively. Asynchronous dynamic output feedback controller is constructed to ensure that the closed-loop mode-dependent time-varying delays Markovian jump neural networks achieve different convergence speeds. The given H∞ performance index is satisfied for the delays not bigger than a given upper bound. Numerical examples are employed to show the effectiveness and correctness of the method presented in this paper.
Stress Distribution and Failure Characteristics for Workface Floor of a Tilted Coal Seam
Jian Sun,Lianguo Wang,Guangming Zhao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.9
A mechanical model for the tilted workface floor along the tilted direction of coal seam was proposed. Stress expressions of an arbitrary point inside the tilted workface floor were deduced. Calculation formula for the maximum failure depth of the lateral floor strata of the tilted workface was also deduced. Based on the Mohr-Coulomb yield criterion, the tilted workfacefloor’s stress distribution, and failure depth and shape were simulated by using FLAC3D software for different coal seam’s dip angles, buried depths, and workface widths. Results show that the concentration coefficient, the peak value and the distance between the peak position of the lateral abutment pressure and the roadway on both sides of the tilted workface decreases with the increases in coal seam’s dip angle. The vertical stress isoclines present a “spoon-shaped” distribution along the tilteddirection of workface. Both sides of the workface form “bubble-shaped” distribution shear stress and its peak value increases first and then decreases with the increases in coal seam’s dip angle and reaches maximum at 30°–35°. The tilted workface floor’s plastic failure zone presents a “spoon-shaped” distribution along the tilted direction of workface, which is large on the lower side and small on the upper side. The plastic zone’s failure depth increases first and then decreases with the increases in the dip angle of coal seam and reaches maximum at 30°.
Differences in the starvation-induced autophagy response in MDA-MB-231 and MCF-7 breast cancer cells
Wanyun Zhu,Hong-Jiang Wei,Hong-Ye Zhao,Hao Qu,Kaixiang Xu,Baoyu Jia,Haifeng Li,Yimin Du,Guangming Liu 한국통합생물학회 2017 Animal cells and systems Vol.21 No.3
Breast cancer is a heterogeneous disease with distinct subtypes that have made targeted therapy of breast cancer challenging. Previous studies have demonstrated that an altered autophagy capacity can influence the development of breast cancer. However, the molecular differences in starvationinduced autophagic responses in MDA-MB-231 and MCF-7 cells have not been fully elucidated. In this study, we found that an increase of LC3B-II protein expression level and a decrease of the p62 protein expression level in both cells treated by Earle’s balanced salt solution. Meanwhile, we observed an increase of autophagosome using transmission electron microscopy and an enhancement in the green fluorescence intensity of LC3B protein by confocal microscopy. Furthermore, we detected the expression of 13 autophagy-related (ATG) genes and 11 autophagy signaling pathway-related genes using qPCR. Among 13 ATG genes, we found that 6 genes were up-regulated in treated MDA-MB-231 cells, while 4 genes were up-regulated and 1 gene was down-regulated in treated MCF-7 cells. In addition, among 11 autophagy signaling pathway-related genes, 7 genes were up-regulated in treated MDA-MB-231 cells, while 5 genes were up-regulated and 1 gene was down-regulated in treated MCF-7 cells. These findings suggest that the autophagic response to starvation was different in the two treated cell lines, which will contribute to further study on the molecular mechanism of starvation-induced autophagy and improve the targeted therapy of breast cancer.