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A decision support system for satellite layout integrating multi-objective optimization and multi-attribute decision making

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Journal of Systems Engineering and Electronics 2019年第3期30卷 535-544页

作者： LIANG Yan’gang QIN Zheng College of Aerospace Science and Engineering National University of Defense Technology

A decision support system, including a multi-objective optimization framework and a multi-attribute decision making approach is proposed for satellite equipment layout. Firstly, given three objectives (to minimize the C.G. offset, the cross moments of inertia and the space debris impact risk), we develop a threedimensional layout optimization model. Unlike most of the previous works just focusing on mass characteristics of the system, a space debris impact risk index is developed. Secondly, we develop an efficient optimization framework for the integration of computer-aided design (CAD) software as well as the optimization algorithm to obtain the Pareto front of the layout optimization problem. Thirdly, after obtaining the candidate solutions, we present a multi-attribute decision making approach, which integrates the smart Pareto filter and the correlation coefficient and standard deviation (CCSD) method to select the best tradeoff solutions on the optimal Pareto fronts. Finally, the framework and the decision making approach are applied to a case study of a satellite platform.

关键词： layout optimization satellite multi-objective optimization Pareto front multi-attribute decision making

INVARIANT DENSITY, LYAPUNOV EXPONENT, AND ALMOST SURE STABILITY OF MARKOVIAN-REGIME-SWITCHING LINEAR SYSTEMS

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Journal of Systems Science & Complexity 2011年第1期24卷 79-92页

作者： Qi HE gang George YIN Department of Mathematics Wayne State University Detroit MI 48202 USA

This paper is concerned with stability of a class of randomly switched systems of ordinary differential equations. The system under consideration can be viewed as a two-component process （X（t）, α（t））, where the system is linear in X（t） and α（t） is a continuous-time Markov chain with a finite state space. Conditions for almost surely exponential stability and instability are obtained. The conditions are based on the Lyapunov exponent, which in turn, depends on the associate invaxiant density. Concentrating on the case that the continuous component is two dimensional, using transformation techniques, differential equations satisfied by the invariant density associated with the Lyapunov exponent are derived. Conditions for existence and uniqueness of solutions are derived. Then numerical solutions are developed to solve the associated differential equations.

关键词： Invariant density Lyapunov exponent randomly switching ordinary differential equation.

Carrier transportation in polycrystalline CuInSe_2 thin films with Cu-deficient grain boundaries

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Rare Metals 2015年第7期34卷 510-516页

作者： Bo Yin Chao-gang Lou School of Electronic Science and Engineering Southeast University

The interface energies and electronic structures of(112) grain boundaries of Cu In Se2 thin films were investigated by first-principle *** is found that the grain boundary with a Cu vacancy has low interface energy and exists widely in the *** Cu deficiency may cause the charge imbalance and result in an upward band bending at the grain *** also weakens the repulsion between Cu-3d orbital and Se-4p orbital and leads to the downward shift of valence band *** two mechanisms,namely the band bending from the charge imbalance and the depression of the valence band maximum, have effects on the(112) grain boundaries with different *** change of band structure forms a potential barrier to prevent electrons or holes from approaching the grain boundary and reduces their *** might be used to explain the effects of the grain boundary on carrier transportation and why polycrystalline Cu(In,Ga)Se2thin film solar cells have better performance than single-crystal cells.

关键词： First principle CuInSe2 Grain boundary Interface e

Sensor management of LEO constellation based on covariance control

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Journal of Systems Engineering and Electronics 2019年第2期30卷 393-401页

作者： QIN Zheng LIANG Yan'gang College of Aerospace Science and Engineering National University of Defense Technology

This paper studies the multi-sensor management problem for low earth orbit(LEO) infrared warning constellation used to track a midcourse missile. A covariance control approach, which selects sensor combinations or subset based on the difference between the desired covariance matrix and the actual covariance of each target, is used for sensor management, including some matrix metrics to measure the differentia between two covariance matrices. Besides, to meet the requirements of the space based warning system, the original covariance control approach is improved. Simulation results demonstrate that the covariance control approach is able to provide a better tracking performance by providing a well-designed desired covariance and balance tracking performance goals with system demands.

关键词： sensor management covariance control target tracking accuracy LEO constellation

[Evaluation of the toxicity of perfluorooctanoic acid toward human colorectal cancer cells using multi-dimensional approaches]

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Se pu = Chinese journal of chromatography 2025年第1期43卷 96-103页

作者： Rui-Jia Zhang Ying-Shi Lin Lan-Yin Tu Zi-Tong Chen Wei-Wei Zhang Tian-gang Luan Bao-Wei Chen School of Life and Health Sciences Hainan University Haikou 570228 China. School of Life Sciences Sun Yat-sen University Guangzhou 510275 China. School of Artificial Intelligence Sun Yat-sen University Zhuhai 519082 China. Guangzhou Center for Disease Control and Prevention Guangzhou 510440 China. School of Marine Sciences Sun Yat-sen University Zhuhai 519082 China.

While human exposure to perfluorooctanoic acid (PFOA) can lead to ulcerative colitis, the molecular mechanisms responsible for PFOA-induced intestinal toxicity are unclear. Herein, we examined the toxicity of PFOA toward human colorectal cancer cells (HCT116) from three dimensions: the cytotoxic phenotype, cell respiration, and transcription levels of metabolism-related genes. Formazan was used to assess how PFOA exposure affects HCT116-cell relative viability, after which the mitochondrial respiratory activities of these cells were determined by analyzing extracellular flux. The quantitative real-time polymerase chain reaction (qPCR) method was used to detect metabolism-related gene expression levels. The cytotoxicity assay revealed that the HCT116 showed significantly inhibited relative activities compared to those of the control when exposed to 300 μmol/L PFOA for 48 h (<0.01), with most cells retained at the G0/G1 stage. In contrast, the mitochondrial respiratory activities of the HCT116 were promoted by concentrations of PFOA as low as 50 μmol/L. Two genes related to cellular metabolism (dipeptidase 1 () and sphingosine kinase 1 ()) were found to be related to the PFOA-promoted formation of ulcerative colitis using our self-developed Metabolic Gene and Pathway Query software and Comparative Toxicogenomics Database (CTD). The qPCR studies revealed that and expression levels were enhanced by 8-10 times in HCT116 exposed to 300 μmol/L PFOA relative to the control, whereas this trend was not observed for HCT116 exposed to 50 μmol/L PFOA. Collectively, these results suggest that the respiratory activity of cellular mitochondria may serve as an index for determining the interference effects associated with PFOA and that metabolic pathways mediated by and may be involved in the development of PFOA-induced ulcerative colitis. Future studies should investigate the relationships between changes in metabolism-related genes ( and ) and the mitochondrial respiratory act

关键词： Metabolic Gene and Pathway Query software human colorectal enterotoxicity metabolic disorder perfluorooctanoic acid (PFOA)

Influence of Water Vapor on Silica Membrane： Adsorption Properties and Percolation Effect

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Chinese Journal of Chemical Physics 2015年第3期28卷 345-350,I0002页

作者： Chun-lin Song gang Liu Faculty of Materials and Energy Southwest University Chongqing 400715 China Inorganic Membrane Group MESA+ Institute for Nanotechnology Faculty of Science and Technology University of Twente P.O. Box 217 7500 AE Enschede the Netherlands

The influence of water vapor on silica membrane with pore size of ,-4A has been investigated in terms of adsorption properties and percolation effect at 50 and 90 ℃. Two methods are employed： spectroscopic ellipsometry for water vapor adsorption and gas permeation of binary mixture of helium and H2O The adsorption behaviors on the silica membrane comply with the first-order Langmuir isotherm. The investigation demonstrates that helium flux through the silica membrane decreases dramatically in presence of H20 molecules. The transport of gas molecules through such small pores is believed not to be continuous any more, whereas it is reasonably assumed that the gas molecules hop from one occupied site to another unoccupied one under the potential gradient. When the coverage of H20 molecules on the silica surface increases, the dramatic decrease of helium flux could be related to percolation effect, where the adsorbed H20 molecules on the silica surface block the hopping of helium molecules.

关键词： Silica membrane Percolation effect Adsorption

Power Efficient Sub-Array in Reconfigurable VLSI Meshes

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Journal of Computer Science & Technology 2005年第5期20卷 647-653页

作者： Ji-gang Wu Thambipillai Srikanthan Centre for High Performance Embedded Systems School of Computer Engineering Nanyang Technological University Singapore 639798

Given an m × n mesh-connected VLSI array with some faulty elements, the reconfiguration problem is to find a maximum-sized fault-free sub-array under the row and column rerouting scheme. This problem has already been shown to be NP-complete. In this paper, new techniques are proposed, based on heuristic strategy, to minimize the number of switches required for the power efficient sub-array. Our algorithm shows that notable improvements in the reduction of the number of long interconnects could be realized in linear time and without sacrificing on the size of the sub-array. Simulations based on several random and clustered fault scenarios clearly reveal the superiority of the proposed techniques.

关键词： degradable VLSI mesh reconfiguration heuristic algorithm fault-tolerance NP-complete

Urban stormwater disinfection, quality variability during storage and influence on the freshwater algae: Implications for reuse safety

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Journal of Environmental Sciences 2023年第2期124卷 655-666页

作者： Shanshan Fan gang Wen An Liu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China Shaanxi Key Laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Water Science and Environmental Engineering Research Center College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China

Stormwater reuse is one of the most important ways to mitigate water resource ***,urban stormwater contains many bacteria species,which threaten the reuse ***,stormwater disinfection is highly *** disinfection has been widely conducted in the drinking water and reclaimed water,it is rarely carried out for *** study collected the roof stormwater and undertook chlorination *** typical bacteria,Escherichia coli(***)and Staphylococcus aureus(***)were selected in this study to investigate the disinfection *** is found that bacteria species present in the stormwater had an important influence on disinfection efficiency while the original stormwater quality did not show an obvious ***,when the disinfected stormwater was stored,the stormwater quality was highly variable during its storage process and the variability was affected by bacteria *** *** containing stormwater showed a high variability of quality and *** significantly ***,the *** containing stormwater quality had a relatively low variability and *** did not significantly ***,it is noted that after storage,the dissolved form of stormwater was more positive to the freshwater algae’s growth while the particulate form(including bacteria and other particulate matters)was *** implies that a further treatment such as filtration is needed before the stored stormwater is recharged into receiving waters in order to remove particulate *** research outcomes can provide useful insight to effective stormwater disinfection and ensure reuse safety.

关键词： Stormwater quality Stormwater disinfection Stormwater storage Stormwater reuse Escherichia coli Staphylococcus aureus

Volatiles in the mantle transition zone and their effects on big mantle wedge systems

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National Science Review 2024年第6期11卷 15-18页

作者： Yu Wang Yi-gang Xu State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)

The mantle transition zone (MTZ), located between the upper and lower mantle, is characterized by sudden seismicvelocity discontinuities at depths of 410 and 660 km where significant change in mineralogical composition occurs. As a link between the upper and lower mantle,the MTZ is a layer of special significance in Earth’s deep structure, and a critical interface in geodynamics and material circulation.

关键词： systems effects mantle their transition volatiles wedge zone