Afrika MatematikaPub Date : 2025-04-18DOI: 10.1007/s13370-025-01307-8
G. Murugusundaramoorthy, H. Ö. Güney
{"title":"Universally prestarlike functions associated with generalized telephone numbers","authors":"G. Murugusundaramoorthy, H. Ö. Güney","doi":"10.1007/s13370-025-01307-8","DOIUrl":"10.1007/s13370-025-01307-8","url":null,"abstract":"<div><p>In this paper, we acquaint universally prestarlike generalized functions of order <span>(vartheta )</span> with <span>(vartheta le 1)</span> associated with generalized telephone numbers and we get coefficient bounds for <span>( fin mathscr {R} _{vartheta }^{u}(Psi ))</span> and also for <span>( f^{-1} in mathscr {R} _{vartheta }^{u}(Psi ))</span> which has not been discussed earlier. Further we obtain the Fekete-Szegö functional for the class of universally prestarlike functions and applications to certain probability distribution based on convolution product for such functions.</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":"143845646","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}
Afrika MatematikaPub Date : 2025-04-18DOI: 10.1007/s13370-025-01292-y
Schalk William Human, Jean-Claude Malela-Majika, Pierre Kritzinger
{"title":"Improved runs-rules precedence charts for monitoring the process location parameter","authors":"Schalk William Human, Jean-Claude Malela-Majika, Pierre Kritzinger","doi":"10.1007/s13370-025-01292-y","DOIUrl":"10.1007/s13370-025-01292-y","url":null,"abstract":"<div><p>Runs-rules are typically incorporated into control charts to increase their sensitivity to detect small process shifts. However, a drawback of this approach is that the resulting charts are unable to detect large shifts quickly. In this paper, improved runs-rules are introduced to the nonparametric precedence chart to address this limitation by maintaining the sensitivity to small process shifts, while improving the ability to detect large shifts in the process. Performance comparisons between the proposed precedence charts and the precedence charts with standard runs-rules are made in terms of their respective run-length characteristics. The results reveal that the precedence charts with improved runs-rules are superior to the competing charts in detecting large shifts in the process, while maintaining the same sensitivity in the detection of small shifts. A real-life example from the engineering field is given to demonstrate the application and implementation of the new charts.</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/s13370-025-01292-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845618","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}
Afrika MatematikaPub Date : 2025-04-18DOI: 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, Kashif Ali, Farhana Yasmeen, Muhammad Aamer Rashid, 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}
Afrika MatematikaPub Date : 2025-04-18DOI: 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}
Afrika MatematikaPub Date : 2025-04-18DOI: 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, Aminat O. Ige, Johnson O. Olaleru, 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}
Afrika MatematikaPub Date : 2025-04-07DOI: 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, Amine Jaid, 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}
Afrika MatematikaPub Date : 2025-04-07DOI: 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}
Afrika MatematikaPub Date : 2025-04-07DOI: 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, 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}
Afrika MatematikaPub Date : 2025-04-07DOI: 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, 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}
Afrika MatematikaPub Date : 2025-04-07DOI: 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, 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}