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Strong invariance principle for a counterbalanced random walk

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 370-380页

作者： TAN Hui-qun HU Zhi-shui DONG Liang International Institute of Finance School of ManagementUniversity of Science and Technology of ChinaHefei 230026China center for Basic Teaching and experiment Nanjing University of Science and TechnologyJiangyin 214443China

We study a counterbalanced random walkS_(n)=X_(1)+…+X_(n),which is a discrete time non-Markovian process andX_(n) are given recursively as follows.For n≥2,X_(n) is a new independent sample from some fixed law̸=0 with a fixed probability p,andX_(n)=−X_(v(n))with probability 1−p,where v(n)is a uniform random variable on{1;…;n−1}.We apply martingale method to obtain a strong invariance principle forS_(n).

关键词： random walk martingale invariance principle

Predictive sliding-mode control of networked high-order fully actuated systems under random deception attacks

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science China(Information sciences) 2023年第9期66卷 50-63页

作者： Da-Wei ZHANG Guo-Ping LIU center for Control Theory and Guidance technology Harbin Institute of Technology center for Control science and technology Southern University of Science and Technology

This research addresses the output tracking of networked high-order fully actuated(NHOFA)systems under random deception attacks in the sensor to networked controller(SNC) and networked controller to actuator(NCA) communication channels, where a Bernoulli process represents the launching success rate of random deception attacks. A successful attack involves the output and control signals being tampered with by the injection of false data. Herein, a predictive sliding-mode control scheme is proposed to achieve the security tracking. In this scheme, a sliding-mode variable is introduced to defend the random deception attacks by enhancing the robustness of closed-loop systems. An incremental HOFA(IHOFA) prediction model is developed using a Diophantine equation as an alternative to the traditional reduced-order prediction model. Through this IHOFA prediction model, the multistep ahead predictions of the sliding-mode variable are constructed to optimize the tracking performance and defense of random deception attacks. By utilizing the Lyapunov function and linear matrix inequality(LMI) approach, a sufficient and necessary condition is proposed to ensure stability and high tracking performance of closed-loop NHOFA systems. Herein, an experiment on the tracking control of an air-bearing spacecraft(ABS) simulator is performed to demonstrate the effectiveness and practicability of the predictive sliding-mode control scheme.

关键词： NHOFA systems random deception attacks predictive sliding-mode control stability and tracking performance tracking control of ABS simulator

The Application of Permanent Magnet Synchronous Motor with Small Electrical Time Constant in Fiber Positioner

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Research in Astronomy and Astrophysics 2024年第1期24卷 212-222页

作者： Shaoxiong Guo Yan Yang Yanbin Yin Yihu Tang Yang Tian Chao Zhai Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China School of Biomedical Engineering Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230026China experiment center of Engineering and Material science University of Science and Technology of ChinaHefei 230026China

With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a suitable replacement for Faulhaber Precistep stepper motors.However,the small electrical time constant of such coreless motors poses a challenge,as the problem of severe commutation torque ripple in a fiber positioner running a position loop has been tricky.To overcome this challenge,it is advised to increase the Pulse Width Modulation(PWM)frequency as much as possible to mitigate the effects of the current fluctuation.This must be done while ensuring adequate resolution of the PWM generator.By employing a voltage open-loop field-oriented control based on a modulation frequency of 1 MHz,the drive current only costs 25 m A under a 3.3 V power supply.The sine degree of phase current is immaculate,and the repeat positioning accuracy can reach 2μm.Moreover,it is possible to further shrink the bill of devices and the layout area of the Printed Circuit Board,especially in sizesensitive applications.This device has been developed under the new generation of The Large Sky Area MultiObject Fiber Spectroscopic Telescope.

关键词： instrumentation:adaptive optics instrumentation:spectrographs proper motions reference systems

Demonstration of a fully differential VGA chip with small THD for ECG acquisition system

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Journal of Semiconductors 2015年第10期36卷 117-122页

作者：肖功利覃玉良徐卫林韦保林段吉海韦雪明 School of Information and Communication Guilin University of Electronic Technology Guangxi experiment center of Information science

We present both a theoretical and experimental demonstration of a fully differential variable gain am- plifier （VGA） with small total harmonic distortion （THD） for an electrocardiogram （ECG） acquisition system. Capacitive feedback technology is adopted to reduce the nonlinearity of VGA. The fully differential VGA has been fabricated in SMIC 0.18-μm CMOS process, and it only occupies 0.11 mm2. The measurements are in good agreement with simulation results. experimental results show that the gain of VGA changes from 6.17 to 43.75 dB with a gain step of 3 dB. The high-pass comer frequency and low-pass comer frequency are around 0.22 Hz and 7.9 kHz, respectively. For each gain configuration, a maximal THD of 0.13% is obtained. The fully differential VGA has a low THD and its key performance parameters are well satisfied with the demands of ECG acquisition system application in the UWB wireless body area network.

关键词： fully differential VGA total harmonic distortion ECG acquisition system capacitive feedback

Mechanically robust bamboo node and its hierarchically fibrous structural design

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National science Review 2023年第2期10卷 199-211页

作者： Si-Ming Chen Si-Chao Zhang Huai-Ling Gao Quan Wang LiChuan Zhou Hao-Yu Zhao Xin-Yu Li Ming Gong Xiao-Feng Pan Chen Cui Ze-Yu Wang YongLiang Zhang HengAn Wu Shu-Hong Yu Department of Chemistry Institute of Biomimetic Materials & Chemistry Anhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials & Chemistry Hefei National Research Center for Physical Sciences at the Microscale Institute of Energy Hefei Comprehensive National Science Center University of Science and Technology of China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsEngineering and Materials Science Experiment CenterUniversity of Science and Technology of China Institute of Innovative Materials (I2M) Department of Materials Science and EngineeringDepartment of Chemistry Southern University of Science and Technology

Although short bamboo nodes function in mechanical support and fluid exchange for bamboo survival,their structures are not fully understood compared to unidirectional fibrous internodes.Here,we identify the spatial heterostructure of the bamboo node via multiscale imaging strategies and investigate its me chanical properties by multimodal mechanical tests.We find three kinds of hierarchical fiber reinforcement schemes that originate from the bamboo node,including spatially tightened interlocking,triaxial interconnected scaffolding and isotropic intertwining.These reinforcement schemes,built on porous vascular bundles,microfibers and more-refined twist-aligned nanofibers,govern the structural stability of the bamboo via hierarchical toughening.In addition,the spatial liquid transport associated with these multiscale fibers within the bamboo node is experimentally verified,which gives perceptible evidence for life-indispensable multidirectional fluid exchange.The functional integration of mechanical reinforcement and liquid transport reflects the fact that the bamboo node has opted for elaborate structural optimization rather than ingredient richness.This study will advance our understanding of biological materials and provide insight into the design of fiber-reinforced structures and biomass utilization.

关键词： biological materials bamboo node hierarchical fiber structural reinforcement functional integration

Transcriptome profile and its partly verification of human hepatocellular carcinoma cells exposed to Yuzhizi(Fructus Akebiae Quinatae) seed extract

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Journal of Traditional Chinese Medicine 2022年第6期42卷 922-931页

作者： FAN Xiaoyan LI Mingzhe CHEN Long LIANG Chao LU Wenli PAN Zhiqiang JIA Dongwei PENG Peike FANG Zhaoqin LIU Xiaomei Department of experimental Traditional Chinese Medicine School of Basic Medical ScienceShanghai University of Traditional Chinese MedicineShanghai 201203China experiment center of science and technology Shanghai University of Traditional Chinese MedicineShanghai 201203China

OBJECTIVE: To investigate the efficacy of Yuzhizi(Fructus Akebiae Quinatae) seed extract(FAQSE) on inhibiting the proliferation of hepatocellular carcinoma(HCC) cells in vitro and to explore the anti-HCC action mechanism of FAQSE. METHODS: Human HCC Hep G2 and Huh7 cells were used to investigate the anti-HCC effect of FAQSE in vitro. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide(MTT) method was used to measure cell viability. Affymetrix microarray was adopted to detect the expression of transcriptome. The differentially expressed genes(DEGs) of each cell line were identified. For coDEGs of both cell lines, the gene ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway were enriched using the Database for Annotation, Visualization and Integrated Discovery(DAVID), and the network analysis of protein-protein interaction(PPI) was mapped using the Retrieval of Interacting Genes/Proteins(STRING) and Cytoscape software. Some important genes in the PPI network of coDEGs were selected to verify by quantitative real-time reverse transcription-polymerase chain reaction, Western blot and enzyme-linked immunosorbent assay. RESULTS: FAQSE decreased the viability of Hep G2 and Huh7 cells. There were 211 co-upregulated and 86 codownregualted genes in both cell lines after FAQSE treatment. The enriched GO terms of co-upregulated DEGs were primarily involved cell-cell adhesion, viral process, transcription initiation from RNA polymerase II promoter, positive regulation of transcription from RNA polymerase II promoter and actin cytoskeleton organization. The GO terms of co-downregulated DEGs were mainly enriched in the processes of SRP-dependent cotranslational protein targeting to membrane, viral transcription, nuclear-transcribed m RNA catabolic process, nonsense-mediated decay, translational initiation and r RNA processing. Main KEGG pathways of co-upregulated DEGs were endocytosis, glutathione metabolism, protein processing in endoplasmic reticulum, synaptic vesicle cycle and lysosome. The maj

关键词： carcinoma hepatocellular transcriptome alpha-fetoprotein Yuzhizi(Fructus Akebiae Quinatae)seed extract

Iridium-Doped 10H-Phase Perovskite BaCo_(0.8)Fe_(0.15)Ir_(0.05)O_(3-δ)as an Efficient Oxygen Evolution Reaction Catalyst

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Chinese Journal of Chemistry 2022年第19期40卷 2276-2284页

作者： Huimin Liu Qinxin Luo Jiaping Hu Lianwei Wei Wanqun Zhang Hui Zheng Shusheng Wu Kaibin Tang Hefei National Research center for Physical sciences at the Microscale University of Science and Technology of ChinaHefeiAnhui230026 China Department of Chemistry University of Science and Technology of ChinaHefeiAnhui230026 China Department of Chemistry City University of Hong KongHong KongChina Chemistry experiment Teaching center University of Science and Technology of ChinaHefeiAnhui230026 China

Designing low-cost and high-performance catalysts of electrocatalytic oxygen evolution reaction(OER)has always been one of the hot topics in current research.Hexagonal perovskite materials show great application potential in this field.Here,we synthesized 5%Iridium(Ir)-doped hexagonal phase perovskite BaCo_(0.8)Fe_(0.15)Ir_(0.05)O_(3–δ)(BCFI).Using the Rietveld method to refine the structure,combining with the spherical aberration corrected high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)atomic imaging,we found that BCFI is a ten-layer hexagonal(10H)structure,which belongs to the Purn:x-wiley:1001604X:media:cjoc202200200:cjoc202200200-math-0001m2 space group.In addition,BCFI shows excellent OER catalytic effect and good stability in 1 mol/L KOH solution,and the overpotential reaches 294 mV at a current density of 10 mA cm^(–2).The reduction of Cobalt(Co)valence state induced by Ir doping significantly enhances the OER activity of BCFI.Meanwhile,density functional theory(DFT)calculations show that the 2p-band center of oxygen(O)in BCFI is closer to the Fermi level than that in undoped BaCo_(0.8)Fe_(0.15)Ir_(0.05)O_(3–δ)(BCF),which is beneficial to the OER.This work reveals a novel 10H-BCFI material with excellent OER performance,and provides a basis for the design of hexagonal perovskite materials in OER and other energy conversion fields.

关键词： Electrochemistry Perovskite phases Oxygen evolution reaction Cobalt Iridium

Novel 700 V high-voltage SOI LDMOS structure with folded drift region

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Journal of Semiconductors 2015年第2期36卷 87-91页

作者：李琦李海鸥翟江辉唐宁 Guangxi experiment center of Information science Guilin University of Electronic Technology State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China

A new high-voltage LDMOS with folded drift region （FDR LDMOS） is proposed. The drift region is folded by introducing the interdigital oxide layer in the： Si active layer, the result of which is that the effective length of the drift region is increased significantly. The breakdown characteristic has been improved by the shielding effect of the electric field from the holes accumulated in the surface of the device and the buried oxide layer. The numerical results indicate that the breakdown voltage of 700 V is obtained in the proposed device in comparison to 300 V of conventional LDMOS, while maintaining low on-resistance.

关键词： folded drift region breakdown voltage interdigital oxide layer electric field modulation

A Method for Crude Oil Selection and Blending Optimization Based on Improved Cuckoo Search Algorithm

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China Petroleum Processing & Petrochemical technology 2014年第4期16卷 70-78页

作者： Yang Huihua Ma Wei Zhang Xiaofeng Li Hu Tian Songbai Guangxi experiment center of Information science Guilin University of Electronic Technology Research Institute of Petroleum Processing SINOPEC

Refineries often need to find similar crude oil to replace the scarce crude oil for stabilizing the feedstock property. We introduced the method for calculation of crude blended properties firstly, and then created a crude oil selection and blending optimization model based on the data of crude oil property. The model is a mixed-integer nonlinear programming(MINLP) with constraints, and the target is to maximize the similarity between the blended crude oil and the objective crude oil. Furthermore, the model takes into account the selection of crude oils and their blending ratios simultaneously, and transforms the problem of looking for similar crude oil into the crude oil selection and blending optimization problem. We applied the Improved Cuckoo Search(ICS) algorithm to solving the model. Through the simulations, ICS was compared with the genetic algorithm, the particle swarm optimization algorithm and the CPLEX solver. The results show that ICS has very good optimization efficiency. The blending solution can provide a reference for refineries to find the similar crude oil. And the method proposed can also give some references to selection and blending optimization of other materials.

关键词： crude oil similarity crude oil selection blending optimization mixed-integer nonlinear programming CuckooSearch algorithm