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The Analytical Equation of the Three-point Correlation Function of Galaxies:to the Third Order of Density Perturbation

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Research in Astronomy and Astrophysics 2022年第12期22卷 123-129页

作者： Shu-guang wu Yang Zhang Department of Astronomy Key Laboratory for Researches in Galaxies and CosmologyUniversity of Science and Technology of ChinaHefei 230026China

Applying functional differentiation to the density field with Newtonian gravity,we obtain the static,nonlinear equation of the three-point correlation functionζof galaxies to the third order density *** make the equation closed and perform renormalization of the mass and the Jeans *** the boundary condition inferred from observations,we obtain the third order solutionζ(r,u,θ)at fixed u=2,which is positive,exhibits a Ushape along the angleθ,and decreases monotonously along the radial r up to the range r≤30 h^(-1)Mpc in our *** corresponding reduced Q(r,u,θ)deviates from 1 of the Gaussian case,has a deeper U-shape alongθ,and varies non-monotonously along *** third order solution agrees with the SDSS data of galaxies,quite close to the previous second order solution,especially at large *** indicates that the equations of correlation functions with increasing orders of density perturbation provide a stable description of the nonlinear galaxy system.

关键词： (cosmology:)large-scale structure of universe hydrodynamics gravitation

The Nonlinear Field Equation of the Three-point Correlation Function of Galaxies:to the Second Order of Density Perturbation

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Research in Astronomy and Astrophysics 2022年第4期22卷 160-168页

作者： Shu-guang wu Yang Zhang Department of Astronomy Key Laboratory for Researches in Galaxies and CosmologyUniversity of Science and Technology of ChinaHefei 230026China

Based on the field theory of density fiuctuation under Newtonian gravity,we obtain analytically the nonlinear equation of 3-pt correlation functionζof galaxies in a homogeneous,isotropic,static *** density fiuctuation has been kept up to second *** the Fry-Peebles ansatz and the Groth-Peebles ansatz,the equation ofζbecomes closed and differs from the Gaussian approximate *** the boundary condition inferred from the data of SDSS,we obtain the solutionζ(r,u,θ)at fixed u=2,which exhibits a shallow U-shape along the angleθand,nevertheless,decreases monotonously along the radial *** show its difference with the Gaussian *** a direct criterion of non-Gaussianity,the reduced Q(r,u,θ)deviates from the Gaussianity plane Q=1,exhibits a deeper U-shape alongθand varies weakly along r,agreeing with the observed data.

关键词： gravitation hydrodynamics cosmology:large-scale structure of universe

Resilient observer-based event-triggered control for cyber-physical systems under asynchronous denial-of-service attacks

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Science China(Information Sciences) 2022年第4期65卷 182-196页

作者： Yifang ZHANG Zheng-guang wu Zongze wu Deyuan MENG State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang University School of Automation Guangdong University of Technology Seventh Research Division Beihang University (BUAA) School of Automation Science and Electrical Engineering Beihang University (BUAA)

We develop the resilient observer-based event-triggered control update strategy in this *** is utilized to achieve the input-to-state stability(ISS) of cyber-physical systems(CPSs) when there is an asynchronous denial-of-service(DoS) attack, which is launched by malicious adversaries both on measurement channel and control channel in a random attack strategy. To estimate the unmeasurable states while saving the limited networked bandwidth, an H∞observer-based event-triggered control scheme is first designed to guarantee the ISS of CPSs with economic communication. Moreover, the occurrence of Zeno behavior can be eliminated by providing the existence of a lower positive bound of any two inter-event times. Then, a recursive model of asynchronous DoS attacks is introduced. A resilient control update strategy is proposed and further analyzed to derive the stability criterion of CPSs. At last, a numerical simulation example is given to demonstrate the effectiveness of the introduced control update policy.

关键词： cyber-physical systems input-to-state stability asynchronous DoS attacks H ∞ observer event-triggered control

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Mean square stability for Markov jump Boolean networks

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Science China(Information Sciences) 2020年第1期63卷 190-199页

作者： Liqing WANG Mei FANG Zheng-guang wu State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang University College of Automation Harbin Engineering University

In this paper, one of the stability definitions of Markov jump Boolean networks(MJBNs), called mean square stability(MSS), is investigated. Some necessary and sufficient conditions are presented to guarantee the MSS of such MJBNs. Moreover, one of the necessary and sufficient conditions for MSS is obtained in terms of linear programming, which implies that MSS is equivalent to global stability with probability 1 for MJBNs. Furthermore, the construction of Lyapunov function is given and also another theorem based on the Lyapunov function is derived to ensure the MSS of MJBNs. Finally, a numerical example is provided to illustrate the profits of our results.

关键词： mean square stability MSS Boolean network BN stochastic stability Markovian jump parameters semi-tensor product STP Lyapunov function

Global Smooth Solution to the Incompressible Navier-Stokes-Landau-Lifshitz Equations

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Acta Mathematicae Applicatae Sinica 2023年第1期39卷 135-178页

作者： guang-wu WANG You-de WANG School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006China Hua Loo-Keng Key Laboratory of Mathematics Institute of MathematicsAMSS and School of Mathematical ScienceUCASBeijing 100190China

In this paper, we will investigate the incompressible Navier-Stokes-Landau-Lifshitz equations, which is a system of the incompressible Navier-Stokes equations coupled with the Landau-Lifshitz-Gilbert equations. We will prove global existence of the smooth solution to the incompressible Navier-Stokes-Landau-Lifshitz equation with small initial data in T2or R2and R3.

关键词： incompressible Navier-Stokes-Landau-Lifshitz equations global smooth solution small initial data

Quick identification of guidance law for an incoming missile using multiple-model mechanism

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Chinese Journal of Aeronautics 2022年第9期35卷 282-292页

作者： Yinhan WANG Shipeng FAN Jiang WANG guang wu School of Aerospace Engineers Beijing Institute of TechnologyBeijing 10081China Beijing Aerospace Automatic Institute Beijing 100854China

A guidance law parameter identification model based on Gated Recurrent Unit(GRU)neural network is established. The scenario of the model is that an incoming missile(called missile)attacks a target aircraft(called aircraft) using Proportional Navigation(PN) guidance law. The parameter identification is viewed as a regression problem in this paper rather than a classification problem, which means the assumption that the parameter is in a finite set of possible results is discarded. To increase the training speed of the neural network and obtain the nonlinear mapping relationship between kinematic information and the guidance law parameter of the incoming missile, an output processing method called Multiple-Model Mechanism(MMM) is proposed. Compared with a conventional GRU neural network, the model established in this paper can deal with data of any length through an encoding layer in front of the input layer. The effectiveness of the proposed Multiple-Model Mechanism and the performance of the guidance law parameter identification model are demonstrated using numerical simulation.

关键词： Gated recurrent unit Multiple-model mechanism Neural networks Parameter identification Regression models

Innovation Analysis Approach to Design Parameters of High Speed Train Carriage and Their Intrinsic Complexity Relationships

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Chinese Journal of Mechanical Engineering 2017年第5期30卷 1091-1100页

作者： Shou-Ne Xiao Ming-Meng Wang guang-Zhong Hu guang-wu Yang State Key Laboratory of Traction Power Southwest Jiaotong University School of Mechanical Engineering Sichuan University of Science & Engineering

In view of the problem that it＇s difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out- in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary condi- tions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the appli- cation of forward design method to high-speed trains.

关键词： Train carriage body parameters Complexnetwork Width influence Depth influence Parametercontrol strength

Influence of processing parameters and heat treatment on phase composition and microstructure of plasma sprayed hydroxyapatite coatings

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Transactions of Nonferrous Metals Society of China 2009年第S02期19卷 463-469页

作者： ZHAO Guo-liang WEN guang-wu wu Kun School of Materials Science and Engineering Harbin Institute of Technology(Weihai)Weihai 264209China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Air plasma spraying process was employed to fabricate various hydroxyapatite(HA)coatings on titanium *** influence of processing parameters on the phase composition and the microstructure of the obtained coatings was *** effect of heat treatment on as-sprayed coating in terms of the crystallinity and microstructure was also *** phase composition of coatings was analyzed by X-ray diffraction(XRD)and *** surface and cross-section morphologies and microstructure of coatings as well as the morphology of feedstock were evaluated using scanning electron microscope(SEM).The crystallization temperature of amorphous HA phase in as-sprayed coating was examined by using differential thermal analysis(DTA). The results suggest that phase composition and microstructure of as-sprayed HA coatings strongly depend on the spraying parameters,and heat treatment at 760 ℃for 2 h is one of effective means for increasing the crystallinity and improvement in microstructure of as-sprayed HA coatings.

关键词： hydroxyapatite coatings plasma spraying processing parameters heat treatment

Recovery of the Solitons Using a Lattice Boltzmann Model

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Chinese Physics Letters 1999年第2期16卷 109-110页

作者： YAN guang-wu SONG Min Laboratory for Nonlinear Mechanics of Continuous Media Institute of MechanicsChinese Academy of SciencesBeijing 100080 Department of Mathematics Jilin UniversityChangchun 130023 Division of Foundation Jilin Province Architect CollegeChangchun 130053

We formulate a lattice Boltzmann model which simulates Korteweg-de Vries equation by using a method of higher moments of lattice Boltzmann *** a series of lattice Boltzmann equations in different time scales and the conservation law in time scale t0,we obtain equilibrium distribution *** numerical examples show that the method can be used to simulate soliton.

关键词： equation. function. lattice