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Afrika Matematika最新文献

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Well-posedness and stability of coupled system of wave and strongly damped Petrovsky equations with internal fractional damping 具有内分数阶阻尼的波动与强阻尼Petrovsky方程耦合系统的适定性与稳定性
IF 0.9
Afrika Matematika Pub Date : 2025-01-18 DOI: 10.1007/s13370-025-01238-4
Sara Zouatnia, Salah Boulaaras, Nour Eddine Amroun, Mohammed Said Souid
{"title":"Well-posedness and stability of coupled system of wave and strongly damped Petrovsky equations with internal fractional damping","authors":"Sara Zouatnia,&nbsp;Salah Boulaaras,&nbsp;Nour Eddine Amroun,&nbsp;Mohammed Said Souid","doi":"10.1007/s13370-025-01238-4","DOIUrl":"10.1007/s13370-025-01238-4","url":null,"abstract":"<div><p>We study a coupled system of waves and strongly damped Petrovsky equations with internal fractional damping in a bounded domain. After demonstrating that the system is well-posed using the semigroup theory of linear operators and a conclusion established by Borichev and Tomilov, we analyze the systems stability.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On star statistically compactness 关于星的统计紧致性
IF 0.9
Afrika Matematika Pub Date : 2025-01-17 DOI: 10.1007/s13370-025-01270-4
Prasenjit Bal, Debjani Rakshit, Susmita Sarkar
{"title":"On star statistically compactness","authors":"Prasenjit Bal,&nbsp;Debjani Rakshit,&nbsp;Susmita Sarkar","doi":"10.1007/s13370-025-01270-4","DOIUrl":"10.1007/s13370-025-01270-4","url":null,"abstract":"<div><p>In a space <i>X</i>, if for every countable open cover <span>(mathcal {U} ={U_n:n in textbf{N}})</span> of <i>X</i>, we can find a subcover <span>({mathcal {V}} = {U_{m_k}:k in textbf{N}})</span> such that <span>(delta ({m_k: U_{m_k} in {mathcal {V}} })=0)</span> then the space is called a statistically compact space. Extending the recent works of Sarkar, Bal, and Rakshit on statistically compactness, we investigate statistically compactness of a topological space in the star-operator’s background. The concept of star statistically compactness is contrasted to other topological features. This study explains the attributes of star statistically compactness and its subspaces under diverse circumstances, especially under open continuous surjection.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Population oscillations in a three-species food chain model and their possible control: a Z-type control approach 三种食物链模型中的种群振荡及其可能的控制：z型控制方法
IF 0.9
Afrika Matematika Pub Date : 2025-01-16 DOI: 10.1007/s13370-025-01268-y
Kaushik Kayal, Sudip Samanta, Joydev Chattopadhyay
{"title":"Population oscillations in a three-species food chain model and their possible control: a Z-type control approach","authors":"Kaushik Kayal,&nbsp;Sudip Samanta,&nbsp;Joydev Chattopadhyay","doi":"10.1007/s13370-025-01268-y","DOIUrl":"10.1007/s13370-025-01268-y","url":null,"abstract":"<div><p>In our experiment, we investigate a model of a three-species food chain that includes the predation-driven Allee effect. Within this framework, we propose and analyze an application of a Z-type control mechanism. Our findings reveal that the predation pressure exerted by the intermediate predator on the prey population induces chaos through period-doubling bifurcation. To confirm the presence of chaos, we compute the Lyapunov exponents. Subsequently, we introduce an indirect Z-control mechanism across different trophic levels of the food chain model. Specifically, we apply the Z-control method to the top predator to regulate the population fluctuations of the intermediate predator. Furthermore, we employ the Z-type controller on the intermediate predator population to govern the oscillations in the prey population, leading to the eradication of chaos from the system. Additionally, we observe that gestation delay in the top predator can trigger population oscillations within the system. We also find that implementing the indirect Z-controller to the top predator population can suppress population oscillations in the delayed system. Our research establishes the fundamental concept that the Z-type control method serves as the most efficient controller across various dynamical regimes of the uncontrolled system. It facilitates the regulation of all kinds of oscillations within the system and can replace population oscillation with a predefined stable steady-state, which is vital for promoting ecosystem stability. Our experiment emphasizes the importance of control mechanisms in managing population fluctuations and highlights the potential of Z-type control mechanisms in predator–prey interaction strategies.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Aggregated multi-stability for a class of (mathfrak {J})-Hilfer fractional differential equations via Mittag-Leffler and hypergeometric type functions 基于Mittag-Leffler和超几何型函数的(mathfrak {J}) -Hilfer分数阶微分方程的聚类多稳定性
IF 0.9
Afrika Matematika Pub Date : 2025-01-16 DOI: 10.1007/s13370-025-01245-5
Safoura Rezaei Aderyani, Luís P. Castro, Reza Saadati, Choonkil Park
{"title":"Aggregated multi-stability for a class of (mathfrak {J})-Hilfer fractional differential equations via Mittag-Leffler and hypergeometric type functions","authors":"Safoura Rezaei Aderyani,&nbsp;Luís P. Castro,&nbsp;Reza Saadati,&nbsp;Choonkil Park","doi":"10.1007/s13370-025-01245-5","DOIUrl":"10.1007/s13370-025-01245-5","url":null,"abstract":"<div><p>We propose a new concept of stability, called here as “aggregated multi-stability”, which is based on multiple aggregation functions and also uses Mittag-Leffler and hypergeometric functions. This is inspired by the general framework of the Ulam, Hyers and Rassias types of stability, but differs in essence both in the multi-dependency of various aggregation functions and in choosing special functions to play the role of controllers. This notion is applied here to a class of <span>(mathfrak {J})</span>-Hilfer fractional differential equations for which we identify sufficient conditions to guarantee its aggregated multi-stability.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On the Kato-Rellich theorem and applications for multi-subordinate perturbations 多隶属摄动的Kato-Rellich定理及其应用
IF 0.9
Afrika Matematika Pub Date : 2025-01-14 DOI: 10.1007/s13370-025-01244-6
Abdessattar Lafi
{"title":"On the Kato-Rellich theorem and applications for multi-subordinate perturbations","authors":"Abdessattar Lafi","doi":"10.1007/s13370-025-01244-6","DOIUrl":"10.1007/s13370-025-01244-6","url":null,"abstract":"<div><p>In this paper, we study the so called Kato-Rellich theorem. We prove a similar result for multi-subordinate perturbation. Moreover, we apply this result to study a perturbed operator of Nagy and <span>(n times n)</span> block matrices of linear operators. The obtained results are of importance to be applicated to study the Schrödinger operators. Finally, we give an application to a Gribov operator in Bargmann space.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Tighter underestimator for bivariate global optimization 二元全局优化的更紧低估器
IF 0.9
Afrika Matematika Pub Date : 2025-01-13 DOI: 10.1007/s13370-024-01235-z
Mohand Ouanes
{"title":"Tighter underestimator for bivariate global optimization","authors":"Mohand Ouanes","doi":"10.1007/s13370-024-01235-z","DOIUrl":"10.1007/s13370-024-01235-z","url":null,"abstract":"<div><p>We propose in this paper a tighter underestimator for <span>(C^{2})</span>-nonconvex bivariate functions. We show that it is tighter than the classical <span>(alpha -)</span>BB underestimator. A branch and bound algorithm with this tighter underestimator is developed to solve bivariate global optimzation problems. The triangulation is used as an exhaustive subdivision, and a convex/concave test is added to accelerate the convergence of our branch and bound algorithm.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A model for the dynamics of COVID-19 infection transmission in human with latent delay 具有潜伏延迟的COVID-19人感染传播动力学模型
IF 0.9
Afrika Matematika Pub Date : 2025-01-11 DOI: 10.1007/s13370-024-01226-0
Amar N. Chatterjee, Teklebirhan Abraha, Fahad Al Basir, Delfim F. M. Torres
{"title":"A model for the dynamics of COVID-19 infection transmission in human with latent delay","authors":"Amar N. Chatterjee,&nbsp;Teklebirhan Abraha,&nbsp;Fahad Al Basir,&nbsp;Delfim F. M. Torres","doi":"10.1007/s13370-024-01226-0","DOIUrl":"10.1007/s13370-024-01226-0","url":null,"abstract":"<div><p>In this research, we have derived a mathematical model for within human dynamics of COVID-19 infection using delay differential equations. The new model considers a ’latent period’ and ’the time for immune response’ as delay parameters, allowing us to study the effects of time delays in human COVID-19 infection. We have determined the equilibrium points and analyzed their stability. The disease-free equilibrium is stable when the basic reproduction number, <span>(R_0)</span>, is below unity. Stability switch of the endemic equilibrium occurs through Hopf-bifurcation. This study shows that the effect of latent delay is stabilizing whereas immune response delay has a destabilizing nature.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Periodicity and positivity of solutions for first-order nonlinear neutral differential equations with iterative terms and impulsive effects 具有迭代项和脉冲效应的一阶非线性中立型微分方程解的周期性和正性
IF 0.9
Afrika Matematika Pub Date : 2025-01-11 DOI: 10.1007/s13370-025-01237-5
Mimia Benhadri, Tomás Caraballo
{"title":"Periodicity and positivity of solutions for first-order nonlinear neutral differential equations with iterative terms and impulsive effects","authors":"Mimia Benhadri,&nbsp;Tomás Caraballo","doi":"10.1007/s13370-025-01237-5","DOIUrl":"10.1007/s13370-025-01237-5","url":null,"abstract":"<div><p>In the present paper, sufficient conditions for the existence of bounded positive periodic solutions are established for a class of nonlinear neutral differential equations with iterative source term and nonlinear impulses. The form including an impulsive term of the equations in this paper is rather general and incorporates as special cases various problems which have been studied extensively in the literature. Transforming the considered equation to an equivalent integral equation, we prove the existence of positive periodic solutions using a Krasnoselskii fixed point theorem for the sum of a contraction and a compact mapping. Finally, we present an example to illustrate the effectiveness of our results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142962989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An efficient estimation of finite population mean through difference estimator in systematic sampling 用系统抽样差分估计器估计有限总体均值的一种有效方法
IF 0.9
Afrika Matematika Pub Date : 2025-01-10 DOI: 10.1007/s13370-024-01234-0
Surya K. Pal, Sagir A. Mahmud, Housila P. Singh
{"title":"An efficient estimation of finite population mean through difference estimator in systematic sampling","authors":"Surya K. Pal,&nbsp;Sagir A. Mahmud,&nbsp;Housila P. Singh","doi":"10.1007/s13370-024-01234-0","DOIUrl":"10.1007/s13370-024-01234-0","url":null,"abstract":"<div><p>This paper addresses the problem of estimating the finite population mean <span>(overline{Y})</span> of the study variable <span>(y)</span> using two auxiliary variables in systematic sampling. We have suggested a difference-type estimator and its improved version, and then their properties have been studied. It has been shown that the proposed class of estimators is more efficient than the recently proposed estimators due to Tailor et al. (Stat Transit 14: 391–398, 2013) and Khan and Singh (J Prob Stat https://doi.org/10.1155/2015/248374, 2015). An empirical study has been undertaken to evaluate the performance of the suggested estimator over other existing estimators.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An accelerated Tseng type method for solving zero point problems and certain optimization problems 求解零点问题及若干优化问题的加速Tseng型方法
IF 0.9
Afrika Matematika Pub Date : 2025-01-09 DOI: 10.1007/s13370-024-01217-1
A. A. Mebawondu, H. A. Abass, O. K. Oyewole
{"title":"An accelerated Tseng type method for solving zero point problems and certain optimization problems","authors":"A. A. Mebawondu,&nbsp;H. A. Abass,&nbsp;O. K. Oyewole","doi":"10.1007/s13370-024-01217-1","DOIUrl":"10.1007/s13370-024-01217-1","url":null,"abstract":"<div><p>In this paper, we proposed a modified Tseng’s splitting iterative algorithm for approximating a solution of split feasibility problem for zero and fixed point problems. By incorporating an inertial extrapolation method and Halpern iterative technique, we established a strong convergence result for approximating a solution of split fixed point problem for a nonexpansive and quasinonexpansive mapping which is also a zero point of sum of two monotone operators in the framework of real Hilbert spaces. Furthermore, we present a numerical example to support our main result. The results obtained in this paper improve, extend and unify some related results in the literature.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-024-01217-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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