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Afrika Matematika最新文献

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Optimal classes of estimators for population mean using higher order moments 利用高阶矩对总体均值进行最优估计
IF 0.9
Afrika Matematika Pub Date : 2025-01-08 DOI: 10.1007/s13370-024-01232-2
Shashi Bhushan, Anoop Kumar
{"title":"Optimal classes of estimators for population mean using higher order moments","authors":"Shashi Bhushan,&nbsp;Anoop Kumar","doi":"10.1007/s13370-024-01232-2","DOIUrl":"10.1007/s13370-024-01232-2","url":null,"abstract":"<div><p>This paper considers some optimal classes of difference and ratio type estimators for the estimation of population mean using higher order moments viz variance of auxiliary variable with the aim of improvement over its entrants existing till date. The bias and mean square error of the considered estimators are derived using Taylor series method up to the first order of approximation. The theoretical results have been determined and appraised with a computational study using real and artificially generated data sets. The computational results are turned out to be rather advance providing better improvement over the contemporary estimators.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938850","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
(i–v) Pseudo-symmetric fuzzy ideal in semigroups （i-v）半群中的伪对称模糊理想
IF 0.9
Afrika Matematika Pub Date : 2025-01-07 DOI: 10.1007/s13370-024-01236-y
Paltu Sarkar, Sukhendu Kar
{"title":"(i–v) Pseudo-symmetric fuzzy ideal in semigroups","authors":"Paltu Sarkar,&nbsp;Sukhendu Kar","doi":"10.1007/s13370-024-01236-y","DOIUrl":"10.1007/s13370-024-01236-y","url":null,"abstract":"<div><p>In this paper, we discover Anjaneyulu’s pseudo-symmetricity with the help of interval-valued fuzzy membership function. In semigroups, we propose the concept of (<i>i–v</i>) pseudo-symmetric (semipseudo-symmetric, semiprimary) fuzzy ideals and cultivate their different properties. Moreover, we mention some relationships among three (<i>i–v</i>) fuzzy radicals. Lastly, we verify that the (<i>i–v</i>) fuzzy ideals, namely, (<i>i–v</i>) completely prime, (<i>i–v</i>) completely semiprime, (<i>i–v</i>) pseudo-symmetric and (<i>i–v</i>) primary fuzzy ideals are equivalent in some specific semigroups.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938945","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
Different solitons associated with 3-dimensional generalized Sasakian-space-forms 与三维广义sasaki空间形式相关的不同孤子
IF 0.9
Afrika Matematika Pub Date : 2025-01-03 DOI: 10.1007/s13370-024-01233-1
Arpan Sardar, Avijit Sarkar
{"title":"Different solitons associated with 3-dimensional generalized Sasakian-space-forms","authors":"Arpan Sardar,&nbsp;Avijit Sarkar","doi":"10.1007/s13370-024-01233-1","DOIUrl":"10.1007/s13370-024-01233-1","url":null,"abstract":"<div><p>In the present paper we characterize 3-dimensional generalized Sasakian-space-forms admitting some solitons such as Einstein solitons, <span>(eta )</span>-Einstein solitons,<span>(eta )</span>-Ricci solitons, gradient <span>(eta )</span>-Ricci solitons and <span>(eta )</span>-Yamabe solitons. First we show that an Einstein soliton on a 3-dimensional generalized Sasakian-space-form <span>(M(f_1,f_2,f_3))</span> becomes a Ricci soliton and the soliton is shrinking, steady and expanding according as <span>((f_1 - f_3) &lt; 0, = 0)</span> and <span>(&gt; 0)</span>, respectively, where <span>(f_1)</span>, <span>(f_2)</span> and <span>(f_3)</span> are smooth functions. Also, we establish that if a 3-dimensional generalized Sasakian-space-form <span>(M(f_1,f_2,f_3))</span> admits a gradient <span>(eta )</span>-Ricci soliton with potential function <i>f</i>, then <span>(f = log(frac{f_1-f_3}{k})^2,)</span> where <i>k</i> is a constant. Next, we prove that if a 3-dimensional generalized Sasakian-space-form <span>(M(f_1,f_2,f_3))</span> is an <span>(eta )</span>-Yamabe soliton, then the soliton reduces to a Yamabe soliton and the scalar curvature is constant. Finally, we construct an example which proves the existence of our results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925543","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
Inference on overlapping coefficient in two exponential populations based on adaptive type-II progressive hybrid censoring 基于自适应型渐进式混合滤波的两指数种群重叠系数推断
IF 0.9
Afrika Matematika Pub Date : 2024-12-27 DOI: 10.1007/s13370-024-01222-4
Amal Helu
{"title":"Inference on overlapping coefficient in two exponential populations based on adaptive type-II progressive hybrid censoring","authors":"Amal Helu","doi":"10.1007/s13370-024-01222-4","DOIUrl":"10.1007/s13370-024-01222-4","url":null,"abstract":"<div><p>This article considers a life test scheme called the adaptive type-II progressive hybrid censoring scheme introduced by Ng et al. (Naval Res Logist 5(8):687–698, 2009). Based on this type of censoring, we draw inferences about the three well-known measures of overlap, namely Matusita’s measure (<span>( rho )</span>), Morisita’s measure (<span>(lambda )</span>), and Weitzman’s (<span>(Delta )</span>) for two exponential populations with different means. The asymptotic bias and variance of the overlap measure estimators are derived. Monte Carlo evaluations are employed in cases with small sample sizes, where computing the precision or bias of these estimators becomes challenging due to the lack of closed-form expressions for their variances and exact sampling distributions. Confidence intervals for those measures are also constructed via the bootstrap method and Taylor expansion approximation. To emphasize the practical relevance of our proposed estimators, we illustrate their application using a real data set from head and neck cancer research.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889479","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
Generalized Drazin-Riesz invertible elements in a semi-simple Banach algebra 半简单Banach代数中的广义Drazin-Riesz可逆元
IF 0.9
Afrika Matematika Pub Date : 2024-12-27 DOI: 10.1007/s13370-024-01227-z
Othman Abad, Hassane Zguitti
{"title":"Generalized Drazin-Riesz invertible elements in a semi-simple Banach algebra","authors":"Othman Abad,&nbsp;Hassane Zguitti","doi":"10.1007/s13370-024-01227-z","DOIUrl":"10.1007/s13370-024-01227-z","url":null,"abstract":"<div><p>We extend the notion of generalized Drazin-Riesz inverse introduced for bounded linear operators in Živković-Zlatanović and Cvetković (Linear Multilinear Algebra 65(6):1171–1193, 2017) to elements in a complex unital semi-simple Banach algebra. Several characterizations and properties of generalized Drazin-Riesz invertible elements are given. In particular, we extend those of Abad and Zguitti (Ann Funct Anal 12:Article number: 55, 2021), Djordjević and Stanimirovic (Czech Math J 51(3):617–634, 2001) and Živković-Zlatanović and Cvetković (2017).</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890443","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
Alternative technique for equality constraint-based optimization problem under epistemic uncertainty 认知不确定性下基于等式约束的优化问题的替代技术
IF 0.9
Afrika Matematika Pub Date : 2024-12-26 DOI: 10.1007/s13370-024-01228-y
Diptiranjan Behera, Romane Thomas
{"title":"Alternative technique for equality constraint-based optimization problem under epistemic uncertainty","authors":"Diptiranjan Behera,&nbsp;Romane Thomas","doi":"10.1007/s13370-024-01228-y","DOIUrl":"10.1007/s13370-024-01228-y","url":null,"abstract":"<div><p>In this paper, epistemic uncertainty such as the concept of fuzzy set theory has been considered for the analysis of an optimization problem. Accordingly, a fully fuzzy linear programming problem with equality fuzzy constraints has been analysed. Here the involved parameters and variables are considered in terms of trapezoidal fuzzy numbers. In this regard, a new alternative method by converting the fuzzy problem into an equivalent crisp problem has been proposed. In the methodology, for the defuzzification process linear combination-based approach for the fuzzy objective function as well as fuzzy arithmetic are used for the constraints and the non-negative restrictions. Various numerical examples have been solved and compared with the existing results for the validation.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889737","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 normalized Rabotnov function associated with two subclasses of analytic functions with positive coefficients 与两个正系数解析函数子类相关的归一化Rabotnov函数
IF 0.9
Afrika Matematika Pub Date : 2024-12-26 DOI: 10.1007/s13370-024-01231-3
Dania Ahmad AL-Akhras, Basem Aref Frasin
{"title":"On normalized Rabotnov function associated with two subclasses of analytic functions with positive coefficients","authors":"Dania Ahmad AL-Akhras,&nbsp;Basem Aref Frasin","doi":"10.1007/s13370-024-01231-3","DOIUrl":"10.1007/s13370-024-01231-3","url":null,"abstract":"<div><p>Let <span>({mathbb {R}}_{alpha ,beta }(z)=z+{displaystyle sum limits _{n=2}^{infty }}frac{beta ^{n-1}Gamma (1+alpha )}{Gamma ((1+alpha )n)}z^{n})</span> be the normalized Rabotnov functions. The purpose of the present paper is to determine necessary and sufficient conditions and inclusion relation for the normalized Rabotnov function <span>({mathbb {R}}_{alpha ,beta }(z))</span> to be in two subclasses of analytic functions with positive coefficients. Further, we consider an integral operator related to the Rabotnov function <span>({mathbb {R}}_{alpha ,beta }(z))</span>. Several examples of the main results are also considered.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889738","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
Exponential decay in a porous-elastic system with memory and neutral delay 具有记忆和中性延迟的多孔弹性系统的指数衰减
IF 0.9
Afrika Matematika Pub Date : 2024-12-24 DOI: 10.1007/s13370-024-01229-x
Hanni Dridi, Tijani A. Apalara
{"title":"Exponential decay in a porous-elastic system with memory and neutral delay","authors":"Hanni Dridi,&nbsp;Tijani A. Apalara","doi":"10.1007/s13370-024-01229-x","DOIUrl":"10.1007/s13370-024-01229-x","url":null,"abstract":"<div><p>In this paper, we study a memory-type porous-elastic system coupled with a neutral delay on the elasticity equation. We construct some appropriate functionals together with modified energy functional and stabilize the system exponentially depending on the wave speed, the weight of the delay, and the relaxation function.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880394","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
The modified q-Genocchi numbers and polynomials with applications to q-zeta functions 修正的q- genochi数和多项式在q-zeta函数上的应用
IF 0.9
Afrika Matematika Pub Date : 2024-12-24 DOI: 10.1007/s13370-024-01225-1
Armen Bagdasaryan, Serkan Araci, Erkan Ağyüz, Mehmet Acikgoz
{"title":"The modified q-Genocchi numbers and polynomials with applications to q-zeta functions","authors":"Armen Bagdasaryan,&nbsp;Serkan Araci,&nbsp;Erkan Ağyüz,&nbsp;Mehmet Acikgoz","doi":"10.1007/s13370-024-01225-1","DOIUrl":"10.1007/s13370-024-01225-1","url":null,"abstract":"<div><p>In this paper, we introduce the modified <i>q</i>-Genocchi polynomials, investigate their properties, and give their generating function. We obtain a number of new relations and properties for <i>q</i>-Genocchi polynomials, such as addition formula, explicit formula, derivative formula, and multiplication formula. As an application, a new <i>q</i>-analogue of Genocchi zeta function is presented by applying the Mellin transform to the generating function of the modified <i>q</i>-Genocchi polynomials. Finally, we define the <i>q</i>-Genocchi zeta-type functions and then prove their interpolation by the modified <i>q</i>-Genocchi polynomials at negative integers.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880500","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
Common fixed point theorems in complete partial metric space 完全偏度量空间中的公共不动点定理
IF 0.9
Afrika Matematika Pub Date : 2024-12-23 DOI: 10.1007/s13370-024-01224-2
Reza Arab, Bipan Hazarika, Thabet Abdeljawad, Sumati P. Kumari
{"title":"Common fixed point theorems in complete partial metric space","authors":"Reza Arab,&nbsp;Bipan Hazarika,&nbsp;Thabet Abdeljawad,&nbsp;Sumati P. Kumari","doi":"10.1007/s13370-024-01224-2","DOIUrl":"10.1007/s13370-024-01224-2","url":null,"abstract":"<div><p>The objective of this article is to obtain coincidence points and common fixed point theorem in complete partial metric space. We provide some examples to support the usability of our results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875230","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
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