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Afrika Matematika最新文献

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A novel decision-making framework for political candidate evaluation based on picture fuzzy compact spaces 基于图像模糊紧空间的政治候选人评价决策框架
IF 0.8
Afrika Matematika Pub Date : 2026-08-20 DOI: 10.1007/s13370-026-01504-z
K. Tamilselvan, Vikorn Tanaratchat, Zhe Liu
{"title":"A novel decision-making framework for political candidate evaluation based on picture fuzzy compact spaces","authors":"K. Tamilselvan,&nbsp;Vikorn Tanaratchat,&nbsp;Zhe Liu","doi":"10.1007/s13370-026-01504-z","DOIUrl":"10.1007/s13370-026-01504-z","url":null,"abstract":"<div><p>Picture fuzzy sets as a generalization of traditional and intuitionistic fuzzy sets, offer a powerful mathematical framework for modeling uncertainty and imprecision in real-world situations. By incorporating positive, neutral, and negative membership degrees, PFSs provide a more comprehensive representation of human reasoning and decision preferences. This study introduces novel picture fuzzy topological operators for interior and closure, derived from standard picture fuzzy modal operators, and develops a compactification approach for picture fuzzy topological spaces based on picture fuzzy filters. Fundamental topological concepts such as compactness, regularity, normality, and the Hausdorff condition are analyzed within this framework. Furthermore, an efficient decision-making algorithm is proposed to extend the theoretical model to practical applications. The effectiveness of the proposed approach is illustrated through a real-world case study on the 2026 Tamil Nadu election, where picture fuzzy compact spaces are used to model voter preferences and evaluate political candidates in a transparent and unbiased manner. The results demonstrate the potential of picture fuzzy topology as a rigorous decision-support tool that models uncertainty, and promotes equitable political evaluation.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782775","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
Buzano type inequalities with applications 应用中的Buzano类型不等式
IF 0.8
Afrika Matematika Pub Date : 2026-08-19 DOI: 10.1007/s13370-026-01501-2
Fadi Alrimawi, Pintu Bhunia, Hamid Reza Moradi, Mohammad Sababheh
{"title":"Buzano type inequalities with applications","authors":"Fadi Alrimawi,&nbsp;Pintu Bhunia,&nbsp;Hamid Reza Moradi,&nbsp;Mohammad Sababheh","doi":"10.1007/s13370-026-01501-2","DOIUrl":"10.1007/s13370-026-01501-2","url":null,"abstract":"<div><p>In this paper, we present new inner product inequalities that can be viewed as Cauchy-Schwarz-type or Buzano-type inequalities. We then apply these inequalities to derive applications for the numerical radius and the Euclidean operator radius of two operators. The obtained results are compared with many existing results in the literature in a way that supports the advantage of the new findings.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782440","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
Nodal solution for a GJMS-type problem on a closed Riemannian manifold 闭黎曼流形上gjms型问题的节点解
IF 0.8
Afrika Matematika Pub Date : 2026-08-18 DOI: 10.1007/s13370-026-01508-9
Mohamed El Farouk Ounane, Kamel Tahri
{"title":"Nodal solution for a GJMS-type problem on a closed Riemannian manifold","authors":"Mohamed El Farouk Ounane,&nbsp;Kamel Tahri","doi":"10.1007/s13370-026-01508-9","DOIUrl":"10.1007/s13370-026-01508-9","url":null,"abstract":"<div><p>Given a closed Riemannian manifold (<i>M</i>, <i>g</i>) of dimension <span>(nge 3)</span>, we investigate the existence of a nodal solution to the equation </p><div><div><span>$$begin{aligned} P_{g}^{k}u=f|u|^{2^{sharp }-2}u+lambda |u|^{q-2}u, end{aligned}$$</span></div></div><p>where <span>(P_{g}^{k})</span> is a coercive polyharmonic operator, <i>f</i> is a smooth positive function on <i>M</i>, <span>(qin (1,2))</span>, <span>(lambda in (0,+infty ))</span> and <span>( 2^{sharp }:=frac{2n}{n-2k})</span> is the critical Sobolev exponent for the embedding </p><div><div><span>$$begin{aligned} H_{k}^{2}(M)hookrightarrow L^{2^{sharp }}(M). end{aligned}$$</span></div></div><p>Using variational techniques, critical points theory and by applying a very nice minimization relies on a suitable constraint. Supposing that <span>( |Isom(M,g)|ge 2)</span> and for <span>(lambda &gt;0)</span> and small, we prove the existence of a weak nodal solution in <span>(H_{k}^{2}(M))</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782394","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
Jacobson graphs whose Roman domination numbers are at most six 雅各布森图，其罗马统治数最多为6
IF 0.8
Afrika Matematika Pub Date : 2026-08-17 DOI: 10.1007/s13370-026-01510-1
Soheila Khojasteh
{"title":"Jacobson graphs whose Roman domination numbers are at most six","authors":"Soheila Khojasteh","doi":"10.1007/s13370-026-01510-1","DOIUrl":"10.1007/s13370-026-01510-1","url":null,"abstract":"<div><p>Let <i>R</i> be a commutative ring with non-zero identity. The Jacobson graph of <i>R</i> denoted by <span>(mathfrak {J}_{R})</span> is a graph with the vertex set <span>(Rsetminus J(R))</span>, and two distinct vertices <i>x</i> and <i>y</i> are adjacent if and only if <span>(1-xy notin U(R))</span>, where <i>U</i>(<i>R</i>) is the set of all unit elements of <i>R</i>. Let <span>(gamma _{mathfrak {R}}(mathfrak {J}_{R}))</span> be the Roman domination number of <span>(mathfrak {J}_{R})</span>. In this paper, we determine all Artinian commutative rings <i>R</i> with <span>(gamma _{mathfrak {R}}(mathfrak {J}_{R})le 6)</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782228","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 Ricci solitons of four-dimensional pseudo-Riemannian generalized symmetric spaces 四维伪黎曼广义对称空间的广义Ricci孤子
IF 0.8
Afrika Matematika Pub Date : 2026-08-17 DOI: 10.1007/s13370-026-01511-0
Shahroud Azami, Mehdi Jafari
{"title":"Generalized Ricci solitons of four-dimensional pseudo-Riemannian generalized symmetric spaces","authors":"Shahroud Azami,&nbsp;Mehdi Jafari","doi":"10.1007/s13370-026-01511-0","DOIUrl":"10.1007/s13370-026-01511-0","url":null,"abstract":"<div><p>In this article, we investigate generalized Ricci solitons on four-dimensional simply-connected non-symmetric pseudo-Riemannian generalized symmetric spaces and classify them up to isometry.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782203","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 novel fixed point theorem in quasi-metric spaces with applications to the Cauchy problem for nonhomogeneous equations 拟度量空间中一个新的不动点定理及其在非齐次方程Cauchy问题中的应用
IF 0.8
Afrika Matematika Pub Date : 2026-08-17 DOI: 10.1007/s13370-026-01509-8
Kistosil Fahim, Ahmad Hisbu Zakiyudin, Mahmud Yunus
{"title":"A novel fixed point theorem in quasi-metric spaces with applications to the Cauchy problem for nonhomogeneous equations","authors":"Kistosil Fahim,&nbsp;Ahmad Hisbu Zakiyudin,&nbsp;Mahmud Yunus","doi":"10.1007/s13370-026-01509-8","DOIUrl":"10.1007/s13370-026-01509-8","url":null,"abstract":"<div><p>The main objective of this paper is twofold. First, we provide a complete proof of a fixed point theorem for forward <span>(phi G)</span>-contractions in quasi-metric spaces, thereby filling a gap in the recent work of Zakiyudin et al. Second, we apply this theorem to investigate the existence and uniqueness of mild solutions to a nonhomogeneous Cauchy problem. To this end, we introduce a suitable quasi-metric structure on an appropriate function space and show that the associated solution operator satisfies the assumptions of the fixed-point theorem. Consequently, the existence and uniqueness of mild solutions are obtained as an application of the developed theory. Our results generalize previous applications of <span>(phi G)</span>-contractions to the heat equation and illustrate the effectiveness of fixed-point methods in the study of nonhomogeneous evolution equations.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782177","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
Some new estimates for the generalized Fourier transform 广义傅里叶变换的一些新估计
IF 0.8
Afrika Matematika Pub Date : 2026-08-14 DOI: 10.1007/s13370-026-01512-z
Abdessalam Chablaoui, Mohamed El Hamma
{"title":"Some new estimates for the generalized Fourier transform","authors":"Abdessalam Chablaoui,&nbsp;Mohamed El Hamma","doi":"10.1007/s13370-026-01512-z","DOIUrl":"10.1007/s13370-026-01512-z","url":null,"abstract":"<div><p>In this paper, we prove two estimates for the generalized Fourier transform in the space square integrable functions on certain classes of functions characterized by the continuity modulus.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751533","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
Equitable-partition methods for the hamming spectrum and energy of graph families 图族的hamming谱和能量的均衡划分方法
IF 0.8
Afrika Matematika Pub Date : 2026-08-13 DOI: 10.1007/s13370-026-01506-x
Bojana Borovićanin, Nenad Stojanović, Nemanja Vučićević
{"title":"Equitable-partition methods for the hamming spectrum and energy of graph families","authors":"Bojana Borovićanin,&nbsp;Nenad Stojanović,&nbsp;Nemanja Vučićević","doi":"10.1007/s13370-026-01506-x","DOIUrl":"10.1007/s13370-026-01506-x","url":null,"abstract":"<div><p>The Hamming matrix <i>H</i>(<i>G</i>) of a graph <i>G</i> encodes the Hamming distances between the binary incidence strings of its vertices and gives rise to <i>Hamming spectrum</i> and <i>Hamming energy</i> <i>HE</i>(<i>G</i>). Building on recent foundational paper that established bounds for paths and closed-form formulas for regular graphs, we develop a unified approach via equitable partitions to determine the full Hamming spectrum and energy of several graph families, such as semi-regular bipartite graphs, complete multipartite graphs, wheel graphs, windmill graphs and the Dutch windmill graphs. In each of these graph classes we partition the vertex sets into a small number of natural classes so that the corresponding quotient matrix <i>B</i> is only <span>(2times 2)</span> (or <span>(3times 3)</span> in the Dutch windmill case). Diagonalizing these low-dimensional matrices yields explicit eigenvalues for <i>H</i>(<i>G</i>) and hence closed-form expressions for <i>HE</i>(<i>G</i>). Our results significantly extend the list of graphs for which Hamming-based spectral invariants are known in closed form, and illustrate the power of equitable partitions in spectral graph theory.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751609","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
Some bounds for a generalized subclass of bounded turning functions defined by a new differential-difference operator 由一个新的微分-差分算子定义的有界翻转函数的广义子类的一些界
IF 0.8
Afrika Matematika Pub Date : 2026-08-10 DOI: 10.1007/s13370-026-01499-7
Seda Karadeniz, Hatun Özlem Güney
{"title":"Some bounds for a generalized subclass of bounded turning functions defined by a new differential-difference operator","authors":"Seda Karadeniz,&nbsp;Hatun Özlem Güney","doi":"10.1007/s13370-026-01499-7","DOIUrl":"10.1007/s13370-026-01499-7","url":null,"abstract":"<div><p>In this paper, we introduce the concept of the Gelfond-Leontiev Sălăgean-difference operator for an analytic function in the unit disc. This new operator and concept of subordination are used to define a new subclass of analytic univalent functions that consists of several known and new generalizations of bounded turning functions. Some coefficient bounds for this class are considered. Bounds of initial Taylor coefficients and logarithmic coefficients are established. Also, Fekete-Szegö functional and second Vandermonde determinants whose entries are both initial coefficient and logarithmic coefficients are proved.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751033","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
Interesting deformed q-series involving the central Lucasnomial coefficients 有趣的变形q级数涉及中心卢卡斯项系数
IF 0.8
Afrika Matematika Pub Date : 2026-08-04 DOI: 10.1007/s13370-026-01492-0
Ronald Orozco
{"title":"Interesting deformed q-series involving the central Lucasnomial coefficients","authors":"Ronald Orozco","doi":"10.1007/s13370-026-01492-0","DOIUrl":"10.1007/s13370-026-01492-0","url":null,"abstract":"<div><p>In this paper, we derive a variety of interesting <i>q</i>-series that contain central Lucasnomial coefficients. Our approach is based on manipulating deformed basic hypergeometric series. Deformed <i>q</i>-analogues of the Euler, Rogers–Ramanujan, and Exton types are obtained. Additionally, we derive some generating functions of the Lucas-analogue of Catalan numbers.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"37 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750673","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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