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Afrika Matematika最新文献

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On Cayley sum signed graphs-I 关于 Cayley 和符号图-I
IF 0.9
Afrika Matematika Pub Date : 2024-07-27 DOI: 10.1007/s13370-024-01203-7
Sachin Somra, Deepakshi Sharma, Deepa Sinha
{"title":"On Cayley sum signed graphs-I","authors":"Sachin Somra,&nbsp;Deepakshi Sharma,&nbsp;Deepa Sinha","doi":"10.1007/s13370-024-01203-7","DOIUrl":"10.1007/s13370-024-01203-7","url":null,"abstract":"<div><p>The Cayley sum graph is a graph whose vertex comprises elements of an abelian group <i>G</i>, and edges are the sum of these vertices belonging to a subset of <i>G</i>, namely, <i>S</i>. We introduce the Cayley sum signed graph by giving the sign to these edges. An edge receives a positive sign if any of the incident vertices belong to <i>S</i>. Otherwise, it receives a negative sign. We discuss the properties of the Cayley sum signed graph.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797912","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
Principal right congruences on completely 0-simple semigroups 完全 0 简单半群上的主右同余
IF 0.9
Afrika Matematika Pub Date : 2024-07-26 DOI: 10.1007/s13370-024-01204-6
Mojtaba Sedaghatjoo, Roghaieh Khosravi, Mohammad Roueentan
{"title":"Principal right congruences on completely 0-simple semigroups","authors":"Mojtaba Sedaghatjoo,&nbsp;Roghaieh Khosravi,&nbsp;Mohammad Roueentan","doi":"10.1007/s13370-024-01204-6","DOIUrl":"10.1007/s13370-024-01204-6","url":null,"abstract":"<div><p>In this paper principal right congruences on completely 0-simple semigroups are identified which consequently leads to identifying principal right congruences on classes of semigroups namely, Brandt semigroups, right groups, left groups, right zero semigroups, left zero semigroups and rectangular bands. As a consequence of this characterization, we show that the class of right subdirectly irreducible completely 0-simple semigroups with more than 3 elements is that of cocyclic 0-groups. Moreover, we prove that right irreducible completely 0-simple semigroups with more than 3 elements are 0-groups for which nontrivial subgroups have nontrivial intersections.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799555","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
Asymptotic stability of porous-elasticity with microtemparature of second-sound type 具有第二音型微温的多孔弹性的渐近稳定性
IF 0.9
Afrika Matematika Pub Date : 2024-07-26 DOI: 10.1007/s13370-024-01208-2
Tijani A. Apalara, Salim A. Messaoud, Mostafa Zahri
{"title":"Asymptotic stability of porous-elasticity with microtemparature of second-sound type","authors":"Tijani A. Apalara,&nbsp;Salim A. Messaoud,&nbsp;Mostafa Zahri","doi":"10.1007/s13370-024-01208-2","DOIUrl":"10.1007/s13370-024-01208-2","url":null,"abstract":"<div><p>In this work, we establish exponential and polynomial decay results for a one-dimensional porous-elastic system with microtemperatures depending on the system’s parameters. Our results are new and improve some previous literature results where additional damping terms were required to establish the exponential decay result. We also present some numerical tests to illustrate our theoretical results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141799598","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 resolvent of impulsive dynamic singular Sturm–Liouville operators 脉冲动态奇异 Sturm-Liouville 算子的解析子
IF 0.9
Afrika Matematika Pub Date : 2024-07-26 DOI: 10.1007/s13370-024-01205-5
Bilender P. Allahverdiev, Hüseyin Tuna, Hamlet A. Isayev
{"title":"The resolvent of impulsive dynamic singular Sturm–Liouville operators","authors":"Bilender P. Allahverdiev,&nbsp;Hüseyin Tuna,&nbsp;Hamlet A. Isayev","doi":"10.1007/s13370-024-01205-5","DOIUrl":"10.1007/s13370-024-01205-5","url":null,"abstract":"<div><p>In this study, the resolvent operator of the impulsive dynamic singular Sturm–Liouville problem is considered. The spectral function was first established. The integral representation of the resolvent operator is obtained using this function.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798978","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
Existence and uniqueness results for an elliptic equation with blowing-up coefficient and lower order term 具有吹胀系数和低阶项的椭圆方程的存在性和唯一性结果
IF 0.9
Afrika Matematika Pub Date : 2024-07-25 DOI: 10.1007/s13370-024-01207-3
Amine Marah
{"title":"Existence and uniqueness results for an elliptic equation with blowing-up coefficient and lower order term","authors":"Amine Marah","doi":"10.1007/s13370-024-01207-3","DOIUrl":"10.1007/s13370-024-01207-3","url":null,"abstract":"<div><p>This paper deals with the existence and uniqueness results for a class of non-coercive Dirichlet elliptic problems whose model example is </p><div><div><span>$$begin{aligned} left{ begin{aligned}&amp;-textrm{div}Big (frac{1}{(m-u)^beta } (1+|u|)^q |nabla u|^{p-2}nabla u+c(x)|u|^{p-2}u sin (u-m)Big )+g(u)=f textrm{in} Omega , &amp;u=0 textrm{on} {partial Omega }, end{aligned} right. end{aligned}$$</span></div></div><p>where <span>(Omega )</span> is a bounded open subset of <span>({mathbb {R}}^N (Nge 2))</span>, <span>(1&lt; p &lt; N)</span>, <span>(m&gt;0)</span>, <span>(0&lt; beta &lt;1)</span>, <span>(q&gt;0)</span>, |<i>c</i>| belongs to <span>(L^{frac{N}{p-1}}(Omega ))</span> and <i>g</i> is a continuous function in <span>({mathbb {R}})</span> which satisfies the sign condition and the data <i>f</i> belongs to <span>(L^1(Omega ))</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141802340","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
Finite-time stability analysis of fractional fuzzy differential equations with time-varying delay involving the generalized Caputo fractional derivative 涉及广义卡普托分数导数的具有时变延迟的分数模糊微分方程的有限时间稳定性分析
IF 0.9
Afrika Matematika Pub Date : 2024-07-21 DOI: 10.1007/s13370-024-01201-9
Lai Van Phut
{"title":"Finite-time stability analysis of fractional fuzzy differential equations with time-varying delay involving the generalized Caputo fractional derivative","authors":"Lai Van Phut","doi":"10.1007/s13370-024-01201-9","DOIUrl":"10.1007/s13370-024-01201-9","url":null,"abstract":"<div><p>The main results of this paper are to discuss the primary results of fuzzy differential equations with time-varying delay (FDDEs) via the generalized Caputo fractional derivative. We establish the existence of a unique solution for FDDEs using the method of steps and the generalized Gronwall inequality. Sufficient conditions are proposed to ensure the finite-time stability (FTS) of FDDEs. Finally, we explore specific examples to illustrate and reinforce the results obtained.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818712","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 enumeration of hyper nearrings of order less than 4 and their automorphisms 关于阶数小于 4 的超邻域及其自动形态的枚举
IF 0.9
Afrika Matematika Pub Date : 2024-07-15 DOI: 10.1007/s13370-024-01202-8
Somayeh Borhani Nejad Rayeni, Bijan Davvaz
{"title":"On enumeration of hyper nearrings of order less than 4 and their automorphisms","authors":"Somayeh Borhani Nejad Rayeni,&nbsp;Bijan Davvaz","doi":"10.1007/s13370-024-01202-8","DOIUrl":"10.1007/s13370-024-01202-8","url":null,"abstract":"<div><p>In this paper, we partition, enumerate and classify hyper nearrings up to isomorphism of order less than 4 and then determine their automorphism groups.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141645284","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
Completeness properties of interval metric spaces 区间度量空间的完备性
IF 0.9
Afrika Matematika Pub Date : 2024-07-15 DOI: 10.1007/s13370-024-01200-w
Rukhsar Khatun, Md Sadikur Rahman, Amar Kumar Banerjee, Asoke Kumar Bhunia
{"title":"Completeness properties of interval metric spaces","authors":"Rukhsar Khatun,&nbsp;Md Sadikur Rahman,&nbsp;Amar Kumar Banerjee,&nbsp;Asoke Kumar Bhunia","doi":"10.1007/s13370-024-01200-w","DOIUrl":"10.1007/s13370-024-01200-w","url":null,"abstract":"<div><p>The purpose of this paper is to study the completeness properties of interval metric spaces. The idea of convergence and Cauchyness of sequences with respect to an interval metric are studied to introduce the notions of <i>i</i>-convergent and <i>i</i>-Cauchy sequences respectively. Several relevant results including relations between convergent and <i>i</i>-convergent sequences, Cauchy and <i>i</i>-Cauchy sequences are established. A characterization for completeness of an interval metric space is given in terms of completeness of metric spaces.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648737","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
Random forest classifier for high entropy alloys phase diagnosis 用于高熵合金相诊断的随机森林分类器
IF 0.9
Afrika Matematika Pub Date : 2024-07-08 DOI: 10.1007/s13370-024-01198-1
Masoud Yousefi, Khosrow Rahmani, Masoud Rajabi, Ali Reyhani, Mehdi Moudi
{"title":"Random forest classifier for high entropy alloys phase diagnosis","authors":"Masoud Yousefi,&nbsp;Khosrow Rahmani,&nbsp;Masoud Rajabi,&nbsp;Ali Reyhani,&nbsp;Mehdi Moudi","doi":"10.1007/s13370-024-01198-1","DOIUrl":"10.1007/s13370-024-01198-1","url":null,"abstract":"<div><p>The random forest (RF) algorithm is considered as a powerful statistical classifier that is more popular in other fields but is relatively unknown in HEA(s)’s prediction phase. In this research, Random Forest (RF) technique is used to investigate phase selection principles effectively utilizing a large experimental case study on 401 distinct HEAs, comprising 174 <span>(SS)</span>, 54 <span>(IM)</span>, and 173 <span>(SS+IM)</span> phases. The accuracy of the proposed method is almost 10% higher than SVM and KNN for classifying HEA(s). Moreover, the precision of the proposed method is similar to ANN. Experimental results indicate the validity and reliability of the RF-based diagnosis method.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141668935","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 groups associated with the affine subgroups of (Sp_{2n}(2)) 论与(Sp_{2n}(2))的仿射子群相关的群
IF 0.9
Afrika Matematika Pub Date : 2024-06-26 DOI: 10.1007/s13370-024-01197-2
D. M. Musyoka, A. L. Prins, L. N. Njuguna, L. Chikamai
{"title":"On groups associated with the affine subgroups of (Sp_{2n}(2))","authors":"D. M. Musyoka,&nbsp;A. L. Prins,&nbsp;L. N. Njuguna,&nbsp;L. Chikamai","doi":"10.1007/s13370-024-01197-2","DOIUrl":"10.1007/s13370-024-01197-2","url":null,"abstract":"<div><p>The symplectic group <span>(Sp_{2n}(2))</span> has an affine maximal subgroup of structure <span>(ASp_n=2^{2n-1}{:}Sp_{2n-2}(2))</span> which is a split extension of an elementary abelian 2-group <span>(N=2^{2n-1})</span> by <span>(G=Sp_{2n-2}(2))</span>. The vector space <span>(N=2^{2n-1})</span> and its dual <span>(N^{*})</span> are not equivalent as <span>(2n-1)</span> dimensional <i>G</i>-modules over <i>GF</i>(2). Therefore, a split extension of the form <span>(overline{G}_n=N^{*}{:}Sp_{2n-2}(2)ncong N{:}Sp_{2n-2}(2))</span> exists. In this paper, it will be shown that <span>(overline{G}_ncong text {Aut}(2^{2n-2}{:}Sp_{2n-2}(2))= left( 2^{2n-2}{:}Sp_{2n-2}(2)right) {:} 2)</span> for <span>(nge 3)</span>. Moreover, the ordinary irreducible characters of <span>(overline{G}_n)</span> are studied through the lens of Fischer-Clifford theory. As an example, the Fischer-Clifford matrix technique is used to construct the set Irr<span>((overline{G}_5))</span> of the group <span>(overline{G}_5=2^9{:}Sp_{8}(2))</span> which is associated with the affine subgroup <span>(ASp_5=2^9{:}Sp_{8}(2))</span> of <span>(Sp_{10}(2))</span>.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-024-01197-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142413884","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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