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On the Trinajstic Descriptor of some graphs 关于若干图的三角描述符
IF 0.9
Afrika Matematika Pub Date : 2025-04-18 DOI: 10.1007/s13370-025-01314-9
Hafiz M. Fraz, Kashif Ali, Farhana Yasmeen, Muhammad Aamer Rashid, Muhammad Farhan Hanif
{"title":"On the Trinajstic Descriptor of some graphs","authors":"Hafiz M. Fraz,&nbsp;Kashif Ali,&nbsp;Farhana Yasmeen,&nbsp;Muhammad Aamer Rashid,&nbsp;Muhammad Farhan Hanif","doi":"10.1007/s13370-025-01314-9","DOIUrl":"10.1007/s13370-025-01314-9","url":null,"abstract":"<div><p>Topological descriptors play a crucial role in various scientific fields, particularly in analyzing the physico-chemical and thermodynamic properties of chemical compounds. Recently, a new topological descriptor, known as the Trinajstić descriptor, has been introduced. For a simple connected graph <span>( G )</span>, the Trinajstić descriptor is defined as </p><div><div><span>$$begin{aligned} NT(G)= sum (n(x)-n(y))^2 forall x,y in V(G) end{aligned}$$</span></div></div><p>Where <span>( n(x) )</span> is the number of vertices whose distance is lesser to <span>( x )</span> than <span>( y )</span> and <span>( n(y) )</span> is the number of vertices whose distance is lesser to <span>( y )</span> than <span>( x )</span>. In this article, we calculate the Trinajstić descriptor for the Kite graph, Fan graph, and Helm graph, expanding its applicability to these graph structures.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845619","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
Analogues of composition operators in the setting of non-commutative symmetric spaces 非交换对称空间中复合算子的类似物
IF 0.9
Afrika Matematika Pub Date : 2025-04-18 DOI: 10.1007/s13370-025-01315-8
Pierre de Jager
{"title":"Analogues of composition operators in the setting of non-commutative symmetric spaces","authors":"Pierre de Jager","doi":"10.1007/s13370-025-01315-8","DOIUrl":"10.1007/s13370-025-01315-8","url":null,"abstract":"<div><p>Symmetric operator spaces are generalizations of symmetric function spaces such as the classical (commutative) <span>(L^p)</span>-spaces, Orlicz spaces, Lorentz spaces and Banach function spaces. In this setting of (potentially) non-commutative symmetric operator spaces we investigate analogues of composition operators, which are also called quantum composition operators. In particular, we provide sufficient conditions under which a Jordan <span>(*)</span>-homomorphism induces a quantum composition operator between non-commutative symmetric spaces and we characterize those bounded operators between non-commutative symmetric spaces that are quantum composition operators. Furthermore, compactness conditions of quantum composition operators are investigated.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01315-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845645","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
A generalized metric-type structure with some applications 广义度量型结构及其应用
IF 0.9
Afrika Matematika Pub Date : 2025-04-18 DOI: 10.1007/s13370-025-01302-z
Hallowed O. Olaoluwa, Aminat O. Ige, Johnson O. Olaleru, Mujahid Abbas
{"title":"A generalized metric-type structure with some applications","authors":"Hallowed O. Olaoluwa,&nbsp;Aminat O. Ige,&nbsp;Johnson O. Olaleru,&nbsp;Mujahid Abbas","doi":"10.1007/s13370-025-01302-z","DOIUrl":"10.1007/s13370-025-01302-z","url":null,"abstract":"<div><p>The aim of this paper is to introduce a new class of metric-type spaces called O-metric spaces as a generalization of several metric-type spaces in literature, by constructing a triangle-type inequality that accommodates many binary operations including multiplication and division. Possible metric-type spaces are classified into upward and downward O-metric spaces as O-metrics between identical points are not necessarily minimal. Conditions for passage between upward and downward O-metrics are specified, giving rise to various reverse triangle inequalities. Topologies arising from O-metrics are listed, and properties such as O-convergence, sequential continuity, first countability and T<span>(_2)</span> separation are investigated. It is shown that the topology of an O-metric space can be generated by an upward O-metric on the space hence the focus will be on upward O-metric spaces. With the use of polygon inequalities, a theorem on the existence and uniqueness of fixed points of some contractive-like maps is established in the setting of O-metric spaces, and well known results are obtained as corollaries. Applications to the estimation of distances, polygon inequalities, and optimization of entries in some infinite symmetric matrices are also given.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845648","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
Novel common fixed point results for multivalued mappings and a new faster iterative scheme 一种新的多值映射的公共不动点结果和更快的迭代算法
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01301-0
Youssef Touail, Amine Jaid, Driss El Moutawakil
{"title":"Novel common fixed point results for multivalued mappings and a new faster iterative scheme","authors":"Youssef Touail,&nbsp;Amine Jaid,&nbsp;Driss El Moutawakil","doi":"10.1007/s13370-025-01301-0","DOIUrl":"10.1007/s13370-025-01301-0","url":null,"abstract":"<div><p>In the present work, we prove some common fixed point theorems for a pair of multivalued mappings via an auxiliary function, denoted as <span>(beta )</span>. Our results are proved without employing neither the uniform convexity nor the compactness of the space. At the end of the paper, we study the convergence of an iterative process involving multivalued mappings. Under different conditions, our scheme converges faster than existing ones in the literature, which is always preferred in practice.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01301-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793061","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
General stability result of a thermoelastic laminated beam with Coleman-Gurtin law for the heat flux 热通量采用科尔曼-古尔丁定律的热弹性层叠梁的一般稳定性结果
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01304-x
Adel M. Al-Mahdi
{"title":"General stability result of a thermoelastic laminated beam with Coleman-Gurtin law for the heat flux","authors":"Adel M. Al-Mahdi","doi":"10.1007/s13370-025-01304-x","DOIUrl":"10.1007/s13370-025-01304-x","url":null,"abstract":"<div><p>We consider a thermoelastic laminated beam where the heat flux is given by the Coleman-Gurtin’s law. That is </p><div><div><span>$$begin{aligned} tau q(t)+(1-alpha )theta _{x}+alpha int _{0}^{infty } Psi (s)theta _{x}(x, t-s)ds=0,qquad alpha in (0, 1), end{aligned}$$</span></div></div><p>where <span>(theta )</span> is the temperature supposed to be known for negative times. <span>(Psi )</span> is the convolution thermal kernel, nonnegative bounded, and convex summable function on <span>([0, infty ))</span> and belongs to a wide class of relaxation function satisfies the unitary total mass and some additional properties that will be specified in the paper. By using the well-known Dafermos history framework and constructing a suitable Lyapunov functional, we establish general decay results for which the exponential and polynomial decay rates are special cases, depending on some assumptions on the relaxation function and the wave speeds of the system. The result obtained is new and substantially improves earlier results in the literature.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793198","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
Maps of (*)-derivation-type on sums of triple products on (*)-algebras (*) -代数上三重积和上的(*) -导型映射
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01299-5
João Carlos da Motta Ferreira, Maria das Graças Bruno Marietto
{"title":"Maps of (*)-derivation-type on sums of triple products on (*)-algebras","authors":"João Carlos da Motta Ferreira,&nbsp;Maria das Graças Bruno Marietto","doi":"10.1007/s13370-025-01299-5","DOIUrl":"10.1007/s13370-025-01299-5","url":null,"abstract":"<div><p>Let <span>(mathcal {M})</span> be a unital prime complex <span>(*)</span>-algebra having a non-trivial projection. In this paper, we proved that every <span>(*)</span>-derivation-type map <span>(Phi :mathcal {M}rightarrow mathcal {M})</span> on sum of triple products <span>(alpha _{1} abc+alpha _{2} a^{*}cb^{*}+alpha _{3} bac +alpha _{4} ca^{*}b^{*}+alpha _{5} bca+alpha _{6} cb^{*}a^{*},)</span> where the scalars <span>({alpha _{k}}_{k=1}^{6})</span> are rational numbers satisfying some conditions, is an additive <span>(*)</span>-derivation. An application of the main result is also presented.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793060","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
Assessing loan eligibility through correlation matrix approximation for credit estimation 通过信用估计的相关矩阵近似来评估贷款资格
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01303-y
Hajar A. Alshaikh, Suliman S. Al-Homidan
{"title":"Assessing loan eligibility through correlation matrix approximation for credit estimation","authors":"Hajar A. Alshaikh,&nbsp;Suliman S. Al-Homidan","doi":"10.1007/s13370-025-01303-y","DOIUrl":"10.1007/s13370-025-01303-y","url":null,"abstract":"<div><p>The correlation problem is a central focus in statistical analysis and data science, as it aims to quantify the relationships between variables. This paper explores efficient methods for approximating correlation matrices to assess loan eligibility for bank customers. We propose a novel algorithm that utilizes advanced optimization techniques to minimize the difference between actual noisy matrices and approximated correlation matrices. The algorithm is designed for large-scale correlation matrices, such as those with thousands of variables, and employs the interior point primal-dual path-following method. We provide a comprehensive comparative analysis of our methods and the commonly used modified alternating projection method, evaluating their efficacy and computational efficiency based on numerical results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793062","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 (mathbf {RBV_{(p,alpha )}^{0}([a,b])}) variation space as the dual space of (mathbf {L_{(p,alpha )}([a,b])}) 在 (mathbf {RBV_{(p,alpha )}^{0}([a,b])}) 变化空间作为 (mathbf {L_{(p,alpha )}([a,b])}) 的对偶空间上
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01280-2
René Erlin Castillo, Eduard Trousselot
{"title":"On the (mathbf {RBV_{(p,alpha )}^{0}([a,b])}) variation space as the dual space of (mathbf {L_{(p,alpha )}([a,b])})","authors":"René Erlin Castillo,&nbsp;Eduard Trousselot","doi":"10.1007/s13370-025-01280-2","DOIUrl":"10.1007/s13370-025-01280-2","url":null,"abstract":"<div><p>In this paper we study some properties of the space <span>(RBV_{(p,alpha )}^{0}([a,b]))</span>. Among other, we proved that the dual space of <span>(L_{(p,alpha )}([a,b]))</span> may be identified with the space <span>(RBV_{(p,alpha )}^{0}([a,b]))</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01280-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793199","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
Lie group analysis and conservation laws for the time-fractional 3D Bateman–Burgers equation 时间分数阶三维Bateman-Burgers方程的李群分析和守恒律
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01295-9
Nida Zinat, Akhtar Hussain, A. H. Kara, F. D. Zaman
{"title":"Lie group analysis and conservation laws for the time-fractional 3D Bateman–Burgers equation","authors":"Nida Zinat,&nbsp;Akhtar Hussain,&nbsp;A. H. Kara,&nbsp;F. D. Zaman","doi":"10.1007/s13370-025-01295-9","DOIUrl":"10.1007/s13370-025-01295-9","url":null,"abstract":"<div><p>This research delves into analyzing the invariant properties and conservation laws (CLs) governing the (3+1)-dimensional (3D) time-fractional Bateman–Burgers (BB) equation, employing the Riemann Liouville (RL) fractional derivative. The fractional Lie symmetry method is employed to ascertain the symmetry attributes of this equation. Consequently, the equation is transformed into a fractional ordinary differential equation (FODE) using the Erdélyi–Kober (EK) fractional differential operator. Additionally, the paper derives new conserved vectors for the 3D time-fractional BB equation using the formal Lagrangian and a detailed derivation based on the new conservation theorem. The explicit solutions and their stability are also examined and analyzed.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793065","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
LRDP: an R package implementing a new class of decompositions for orthogonal matrices LRDP：一个R包，实现了正交矩阵的一类新的分解
IF 0.9
Afrika Matematika Pub Date : 2025-04-07 DOI: 10.1007/s13370-025-01283-z
Luca Bagnato, Antonio Punzo
{"title":"LRDP: an R package implementing a new class of decompositions for orthogonal matrices","authors":"Luca Bagnato,&nbsp;Antonio Punzo","doi":"10.1007/s13370-025-01283-z","DOIUrl":"10.1007/s13370-025-01283-z","url":null,"abstract":"<div><p>Decompositions of an orthogonal matrix <span>(varvec{Q})</span> are valuable on their own and play a crucial role in statistics by simplifying the often challenging estimation of <span>(varvec{Q})</span> when it is part of a model or method. It’s important to note that, in some cases, any orthogonal matrix generated by permuting and/or flipping the signs of the columns of <span>(varvec{Q})</span> is sufficient; principal component analysis (PCA) is one such example. With this in mind, we propose a decomposition of <span>(varvec{Q})</span>, called LRDP, which allows control over the order and the sign of the columns. Due to its structure, our proposal enables the definition of simplified decompositions that can reproduce <span>(varvec{Q})</span> up to a permutation of the columns (LRD decomposition), up to a sign flip of the columns (LRP decomposition), or up to both (LR decomposition). Additionally, we introduce <b>LRDP</b>, an <span>R</span> package provided as supplementary material, specifically designed to implement our decomposition. We illustrate its functionality using a benchmark dataset from the PCA literature.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01283-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793067","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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