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Stochastic optimal control for norovirus transmission dynamics by contaminated food and water

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Chinese Physics B 2022年第2期31卷 173-188页

作者： Anwarud din Yongjin Li Department of Mathematics Sun Yat-sen UniversityGuangzhou 510275China

Norovirus is one of the most common causes of viral gastroenteritis in the world,causing significant morbidity,deaths,and medical *** this work,we look at stochastic modelling methodologies for norovirus transmission by water,human to human transmission and *** begin,the proposed stochastic model is shown to have a single global positive ***,we demonstrate adequate criteria for the existence of a unique ergodic stationary distribution R0 s>1 by developing a Lyapunov ***,we find sufficient criteria Rsding chronic communicable diseases around the *** approach also focuses on offering a way of generating Lyapunov functions that can be utilized to investigate the stationary distribution of epidemic models with nonlinear stochastic disturbances.

关键词： stochastic norovirus model stochastic transmission stochastic perturbation stochastic stability stochastic optimal control

Exploring the electromagnetic information of metasurfaces

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National Science Review 2020年第12期7卷 1845-1846页

作者： din-Ping Tsai Department of Electronic and Information Engineering The Hong Kong Polytechnic University

Metasurfaces,a 2D counterpart of metamaterials,are made of planar subwavelength-scale meta-atoms with designed *** meta-atoms of a metasurface can be used to couple incident waves to free space with controllable amplitudes,phases and polarizations,yielding many novel photonic devices such as optical meta-lenses[1–4].In recent years,with the bloom of information technologies,

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Qualitative behavior of a discrete SIR epidemic model

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International Journal of Biomathematics 2016年第6期9卷 225-239页

作者： Qamar din Department of MathematicsThe University of Poonch Rawalakot Rawalakot 12350 Pakistan

In this paper, we study the qualitative behavior of a discrete-time epidemic model. More precisely, we investigate equilibrium points, asymptotic stability of both disease^free equilibrium and the endemic equilibrium. Furthermore, by using comparison method, we obtain the global stability of these equilibrium points under certain parametric con- ditions. Some illustrative examples are provided to support our theoretical discussion.

关键词： Discrete epidemic model steady-states local asymptotic stability globalbehavior.

ON DAMPING COEFFICIENT DUE TO PHASE TRANSFORMATION

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Acta Mechanica Sinica 2003年第3期19卷 204-207页

作者： din-YuHSIEH (DivisionofAppliedMathematicsBrownUniversity USA)(ZhouPei-YuanCenterforAppliedMathematicsTsinghuaUniversityBeijing100084China)

The damping coefficient of capillary waves due to the evaporation-condensation process at the interface of the two phases of a fluid is *** highlight the mechanism of the effect of heat and mass transfer across the interface between regions of liquid and vapor,potential flow of incompressible fluids are *** other mechanisms of damping are *** fascilitate the analysis,the method of multiple-scale is employed in the analysis,even though the problem is linear.

关键词： phase transformation damping coefficient capillary wave

The Complex Dynamics of Hepatitis B Infected Individuals with Optimal Control

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Journal of Systems Science & Complexity 2021年第4期34卷 1301-1323页

作者： din Anwarud LI Yongjin SHAH Murad Ali Department of Mathematics Sun Yat-sen UniversityGuangzhou 510275China School of Mathematical Sciences Beiing Normal UniversityBeijing 100875China

This paper proposes various stages of the hepatitis B virus(HBV)besides its transmissibility and nonlinear incidence rate to develop an epidemic *** authors plan the model,and then prove some basic results for the well-posedness in term of boundedness and ***,the authors find the threshold parameter R0,called the basic/effective reproductive number and carry out local sensitive ***,the authors examine stability and hence condition for stability in terms of *** using sensitivity analysis,the authors formulate a control problem in order to eradicate HBV from the population and proved that the control problem actually *** complete characterization of the optimum system was achieved by using the 4th-order Runge-Kutta procedure.

关键词： Hepatitis B epidemic model non-linear incidence normalized sensitivity index numerical simulation optimization theory reproduction number stability analysis

A NOVEL STOCHASTIC HEPATITIS B VIRUS EPIDEMIC MODEL WITH SECOND-ORDER MULTIPLICATIVE α-STABLE NOISE AND REAL DATA

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Acta Mathematica Scientia 2024年第2期44卷 752-788页

作者： Anwarud din Yassine SABBAR 吴鹏 Department of Mathematics Sun Yat-Sen UniversityGuangzhou510275China MAIS Laboratory MAMCS GroupFST ErrachidiaMoulay Ismail University of MeknesP.O.Box 509Errachidia52000Morocco School of Science Hangzhou Dianzi UniversityHangzhou310018China School of Data Sciences Zhejiang University of Finance and EconomicsHangzhou310018China

This work presents an advanced and detailed analysis of the mechanisms of hepatitis B virus(HBV)propagation in an environment characterized by variability and *** on some biological features of the virus and the assumptions,the corresponding deterministic model is formulated,which takes into consideration the effect of *** deterministic model is extended to a stochastic framework by considering a new form of disturbance which makes it possible to simulate strong and significant *** long-term behaviors of the virus are predicted by using stochastic differential equations with second-order multiplicative α-stable *** developing the assumptions and employing the novel theoretical tools,the threshold parameter responsible for ergodicity(persistence)and extinction is *** theoretical results of the current study are validated by numerical simulations and parameters estimation is also ***,we obtain the following new interesting findings:(a)in each class,the average time depends on the value ofα;(b)the second-order noise has an inverse effect on the spread of the virus;(c)the shapes of population densities at stationary level quickly changes at certain values of α.The last three conclusions can provide a solid research base for further investigation in the field of biological and ecological modeling.

关键词： HBV model nonlinear perturbation probabilistic bifurcation long-run forecast numerical simulation

Studies on batch adsorptive removal of cadmium and nickel from synthetic waste water using silty clay originated from Balochistan-Pakistan

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1171-1176页

作者： Abdul Samad Muhammad Imran din Mahmood Ahmed Institute of Chemistry University of the PunjabLahore 54590Pakistan Renacon Pharma Limited Lahore 54600Pakistan

The potentials of silty clay(SC),acquired from Chaman,Balochistan,were investigated as adsorbent for Ni(Ⅱ)and Cd(Ⅱ)removal from contaminated *** influence of different operating factors like dose,pH,temperature,and time of contact was explored,and optimum values were noted under batch adsorption *** study was conducted with varying concentrations of solutions on optimized conditions and different adsorption models i.e.,Langmuir,Freundlich,Temkin and Dubinin-Radushkevich(D-R)isotherm,which were employed to interpret the *** isothermal data of both Ni(Ⅱ)and Cd(Ⅱ)were well fitted to Langmuir isotherm suggesting the formation of monolayer of metal ions on silty *** values of adsorption capacity noted for Ni(Ⅱ)and Cd(Ⅱ)were 3.603 mg·g^-1 and 5.480 mg·g^-1,*** studies affirmed that pseudo second order(PSO)kinetics was being obeyed by the removal of Ni(Ⅱ)and Cd(Ⅱ).Thermodynamic variables like free energy change(ΔG°),enthalpy change(ΔH°)and entropy change(ΔS°)were *** negative value ofΔG°and the positive values ofΔH°andΔS°unfolded that the removal process of both metal ions of by SC was spontaneous,endothermic and feasible.

关键词： Adsorption Kinetics Isotherm Toxicity Silty clay Thermodynamics

Energy Cost and Mean Dwell Times for the Activity of Promoter with Complex Structure

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Journal of Systems Science & Complexity 2019年第2期32卷 510-525页

作者： LI Qingqing din Anwarud ZHOU Tianshou Guangdong Province Key Laboratory of Computational Science School of Mathematics Sun Yat-Sen University

Regulatory molecules present on the core promoter of a gene interact often in a dynamic,highly combinatorial and possibly energy-dependent manner, leading to complex promoter structure and even complex global dynamics. The authors analyze dynamics of an arbitrarily complex promoter from the view of thermodynamics combined with statistic physics. First, the authors formulize transcription factors-mediated promoter kinetics in terms of energy. Then, the authors analyze energetic cost in several representative cases of promoter structure, deriving useful analytical results. Third, the authors derive analytical expressions for mean dwell times of the promoter activity states, experimentally measurable quantities related to the energy cost of promoter dynamics. The overall framework lays a theoretical foundation for analysis of complex promoter kinetics and gene expression dynamics.

关键词： Energetic cost master equation mean dwell time promoter kinetics regulation

Analytical Approach to Space- and *** Burgers Equations

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Chinese Physics Letters 2010年第9期27卷 38-41页

作者： Ahmet Yildirim Syed Tauseef Mohyud-din Department of Mathematics Ege University 35100 Bornova-Izmir Turkey HITEC University Taxila Cantt Pakistan

A scheme is developed to study numerical solution of the space- and time-fractional Burgers equations under initial conditions by the homotopy analysis method. The fractional derivatives are considered in the Caputo sense. The solutions are given in the form of series with easily computable terms. Numerical solutions are calculated for the fractional Burgers equation to show the nature of solution as the fractional derivative parameter is changed.

关键词： Solutions Solutes Fractionation Computers