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Mathematical model and optimal control analysis of coffee berry borer with temperature and rainfall variability

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International Journal of Biomathematics 2024年第5期17卷 177-204页

作者： Abdisa Shiferaw Melese department of Applied mathematics Adama Science and Technology UniversityAdamaEthiopia

This study focuses on a nonlinear deterministic mathematical model for coffee berry borer(Hypothenemus hampei)with temperature and rainfall *** the model analysis,CBB free and coexistence equilibria are *** basic reproduction numbers at a minimum and maximum temperature and rainfall are *** qualitative analysis of the model revealed the scenario for equilibria together with basic reproduction *** local stability of equilibria is established through the Jacobian matrix and the Routh-Hurwitz criteria,while the global stability of equilibria is demonstrated using an appropriate Lyapunov *** normalized sensitivity analysis has also been performed to observe the impact of different parameters on basic reproduction *** proposed model is extended into an optimal control problem by incorporating two control variables,namely,the preventive measure variable based on the separation of susceptible coffee berries from contacting the pests based on biological control and an increase in the death rate of colonizing females of CBB based on chemical *** disease control analysis is examined using Pontryagin's minimum ***,the numerical simulations are performed based on analytical results and are discussed ***,the cost-effectiveness of control strategies to determine the best approach to minimize the CBB burden was *** study is significant in providing reliable information on how one can use mathematical modeling to improve the roles of control strategies and prevention in CBB transmission in a coffee *** outcome of the study may guide public agriculture policymakers on optimal control strategies to control the *** particular,using chemical pesticides is very effective to combat pests with minimum costs.

关键词： Hypothenemus hampei climate variability optimal control cost-effective analysis numerical simulation

A NOTE ON THE GENERAL STABILIZATION OF DISCRETE FEEDBACK CONTROL FOR NON-AUTONOMOUS HYBRID NEUTRAL STOCHASTIC SYSTEMS WITH A DELAY

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Acta Mathematica Scientia 2024年第3期44卷 1145-1164页

作者：冯立超张春艳曹进德武志辉 College of science North China University of Science and TechnologyTangshan063210China School of mathematics Southeast UniversityNanjing210096China department of mathematics Harbin University of Science and TechnologyHarbin150080China

Discrete feedback control was designed to stabilize an unstable hybrid neutral stochastic differential delay system(HNSDDS) under a highly nonlinear constraint in the H_∞ and exponential ***,the existing work just adapted to autonomous cases,and the obtained results were mainly on exponential *** comparison with autonomous cases,non-autonomous systems are of great interest and represent an important ***,discrete feedback control has here been adjusted with a time factor to stabilize an unstable non-autonomous HNSDDS,in which new Lyapunov-Krasovskii functionals and some novel technologies are *** should be noted,in particular,that the stabilization can be achieved not only in the routine H_∞ and exponential forms,but also the polynomial form and even a general form.

关键词： hybrid neutral stochastic differential delay system discrete feedback control general stabilization polynomial stabilization

Context-aware reinforcement learning for cooling operation of data centers with an Aquifer Thermal Energy Storage

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Energy and AI

Energy and AI 2024年第3期17卷 233-246页

作者： Lukas Leindals Peter Grønning Dominik Franjo Dominković Rune Grønborg Junker department of Applied mathematics and computer science Technical University of DenmarkDenmark

Data centers are often equipped with multiple cooling units. Here, an aquifer thermal energy storage (ATES) system has shown to be efficient. However, the usage of hot and cold-water wells in the ATES must be balanced for legal and environmental reasons. Reinforcement Learning has been proven to be a useful tool for optimizing the cooling operation at data centers. Nonetheless, since cooling demand changes continuously, balancing the ATES usage on a yearly basis imposes an additional challenge in the form of a delayed reward. To overcome this, we formulate a return decomposition, Cool-RUDDER, which relies on simple domain knowledge and needs no training. We trained a proximal policy optimization agent to keep server temperatures steady while minimizing operational costs. Comparing the Cool-RUDDER reward signal to other ATES-associated rewards, all models kept the server temperatures steady at around 30 °C. An optimal ATES balance was defined to be 0% and a yearly imbalance of −4.9% with a confidence interval of [−6.2, −3.8]% was achieved for the Cool 2.0 reward. This outperformed a baseline ATES-associated reward of 0 at −16.3% with a confidence interval of [−17.1, −15.4]% and all other ATES-associated rewards. However, the improved ATES balance comes with a higher energy consumption cost of 12.5% when comparing the relative cost of the Cool 2.0 reward to the zero reward, resulting in a trade-off. Moreover, the method comes with limited requirements and is applicable to any long-term problem satisfying a linear state-transition system.

关键词： Data centers ATES Smart energy systems Reinforcement learning Delayed rewards

Conservation laws,Lie symmetries,self adjointness,and soliton solutions for the Selkov–Schnakenberg system

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Communications in Theoretical Physics 2024年第2期76卷 29-44页

作者： Kashif Ali Aly R Seadawy Syed T R Rizvi Noor Aziz department of mathematics COMSATS University IslamabadLahore CampusPakistan mathematics department Faculty of ScienceTaibah UniversityAl-Madinah Al-Munawarah41411Saudi Arabia

In this article,we explore the famous Selkov–Schnakenberg(SS)system of coupled nonlinear partial differential equations(PDEs)for Lie symmetry analysis,self-adjointness,and conservation ***,miscellaneous soliton solutions like dark,bright,periodic,rational,Jacobian elliptic function,Weierstrass elliptic function,and hyperbolic solutions of the SS system will be achieved by a well-known technique called sub-ordinary differential *** these results are displayed graphically by 3D,2D,and contour plots.

关键词： Selkov-Schnakenberg system Lie symmetry analysis conservation laws adjointness integrability

Radial solution of the Logarithmic Laplacian system

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Applied mathematics(A Journal of Chinese Universities) 2024年第1期39卷 114-124页

作者： ZHANG Li-hong NIE Xiao-feng WANG Guo-tao Bashir Ahmad School of mathematics and computer science Shanxi Normal UniversityLinfen 041004China Nonlinear Analysis and Applied mathematics(NAAM)Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia.

The paper generalizes the direct method of moving planes to the Logarithmic Laplacian ***,some key ingredients of the method are discussed,for example,Narrow region principle and Decay at ***,the radial symmetry of th... 详细信息

关键词： the Logarithmic Laplacian system radial symmetry the direct method of moving planes

Cauchy matrix approach to three non-isospectral nonlinear Schrödinger equations

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Communications in Theoretical Physics 2024年第5期76卷 1-15页

作者： Alemu Yilma Tefera Shangshuai Li Da-jun Zhang department of mathematics Shanghai UniversityShanghai 200444China Newtouch Center for mathematics of Shanghai University Shanghai 200444China department of Applied mathematics Faculty of Science and EngineeringWaseda UniversityTokyo 169-8555Japan

This paper aims to develop a direct approach,namely,the Cauchy matrix approach,to non-isospectral integrable *** the Cauchy matrix approach,the Sylvester equation plays a central role,which defines a dressed Cauchy matrix to provideτfunctions for the investigated *** this paper,using the Cauchy matrix approach,we derive three non-isospectral nonlinear Schrödinger equations and their explicit *** equations are generically related to the time-dependent spectral parameter in the Zakharov–Shabat–Ablowitz–Kaup–Newell–Segur spectral *** solutions are obtained from the solutions of unreduced non-isospectral nonlinear Schrödinger equations through complex *** solutions are analyzed and illustrated to show the non-isospectral effects in dynamics of solitons.

关键词： Cauchy matrix approach Sylvester equation nonlinear Schrödinger equation non-isospectral integrable system explicit solution

Patients Transportation in Surgery Scheduling Problem

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Journal of Systems science & Complexity 2024年第3期37卷 1100-1113页

作者： CHIKHI Nacira DJEHICHE Boualem department of Operations Research Faculty of MathematicsUniversity of Science and Technology USTHBBab-Ezzouar 161llAlgeria department of mathematics KTH Royal Institute of TechnologySE-10044 StockholmSweden

The scheduling problem in surgery is difficult because, in addition of the planning of the operating rooms which are the most expensive resources in hospitals, each surgery requires a combination of human and material resources. In this paper, the authors address a surgery scheduling problem which arises in operated health care facility. Moreover, the authors consider simultaneously materiel and human resources. This problem is a three-stages flow shop scheduling environment. The first stage(ward) contains a limited number of resources of the same type(beds);The second stage contains different resources with limited capacity(operating rooms, surgeons, nurses, anesthesiologists)and the third stage contains a limited number of recovery beds. There is also a limited number of transporters(porters) between the ward and the other stages. The objective of the problem is to minimize the completion time of the last patient(makespan). The authors formulate this NP-Hard problem in a mixed integer programming model and conduct computational experiments to evaluate the performance of the proposed model.

关键词： Makespan patient scheduling surgery transport

A Study on the Transmission Dynamics of the Omicron Variant of COVID-19 Using Nonlinear Mathematical Models

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computer Modeling in Engineering & sciences 2024年第6期139卷 2265-2287页

作者： S.Dickson S.Padmasekaran Pushpendra Kumar Kottakkaran Sooppy Nisar Hamidreza Marasi department of mathematics Periyar UniversitySalemTamilnadu636011India Faculty of Engineering and Natural sciences Istanbul Okan UniversityIstanbulTurkey department of mathematics College of Science and Humanities in AlkharjPrince Sattam Bin Abdulaziz UniversityAlkharj11942Saudi Arabia department of Applied mathematics Faculty of MathematicsStatistics and Computer ScienceUniversity of TabrizTabrizIran

This research examines the transmission dynamics of the Omicron variant of COVID-19 using SEIQIcRVW and SQIRV models,considering the delay in converting susceptible individuals into infected *** significant delays eventually resulted in the pandemic’s *** ensure the safety of the host population,this concept integrates quarantine and the COVID-19 *** investigate the stability of the proposed *** fundamental reproduction number influences stability *** to our findings,asymptomatic cases considerably impact the prevalence of Omicron infection in the *** real data of the Omicron variant from Chennai,Tamil Nadu,India,is used to validate the outputs.

关键词： Omicron local stability reproduction number steady states global stability

Study for obtaining the exact solutions for the propagation of pulses in optical fibers

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Communications in Theoretical Physics 2024年第10期76卷 14-25页

作者： Arzu Akbulut Waseem Razzaq Filiz Tascan department of mathematics Faculty of Arts and Science Bursa Uluda? University Math Center House no 87 Rahmanyia Colony department of mathematics and computer sciences Faculty of Arts and Science Eskisehir Osmangazi University

In this study, the exact solutions for the propagation of pulses in optical fibers are *** values are given in the model used, and two nonlinear differential equations are *** equations are reduced to ordinary differential equations with the help of wave transformations. Then, the obtained differential equations are solved by two different methods,namely the modified simplest equation and the modified Kudryashov procedures. The solutions are given by hyperbolic, trigonometric and rational functions and the results are useful for optics,engineering and other related areas. Finally three-dimensional, contour and two-dimensional shapes are given for some solutions. These figures are important for understanding the motion of the wave. The given methods are applied to the equations for the first time. To the best of the authors' knowledge, these results are new and have not been obtained in the literature. The results are useful for applied mathematics, physics and other related areas.

关键词： exact solutions the modified simplest equation procedure traveling wave transformation