发布求助
文献互助 智能选刊 最新文献

Ukrainian Mathematical Journal最新文献

筛选
英文 中文
On a Functional Equation Characterizing Some Probability Distributions 论表征某些概率分布的函数方程
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-07-30 DOI: 10.1007/s11253-024-02311-0
Justyna Jarczyk, Witold Jarczyk
{"title":"On a Functional Equation Characterizing Some Probability Distributions","authors":"Justyna Jarczyk, Witold Jarczyk","doi":"10.1007/s11253-024-02311-0","DOIUrl":"https://doi.org/10.1007/s11253-024-02311-0","url":null,"abstract":"<p>We find all nonnegative solutions <i>f</i> of the equation\u0000</p><span>$$fleft(xright)=prod_{j=1}^{n}f{left({s}_{j}xright)}^{{p}_{j}},$$</span><p>defined in a one-sided vicinity of 0 and having a prescribed asymptotic at 0<i>.</i> The main theorem extends a result obtained by J. A. Baker [<i>Proc. Amer. Math. Soc.</i>, <b>121</b>, 767 (1994)].</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Fractal Embedded Boxes of Bifurcations 分形嵌入式分岔盒
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-07-30 DOI: 10.1007/s11253-024-02309-8
Christian Mira
{"title":"Fractal Embedded Boxes of Bifurcations","authors":"Christian Mira","doi":"10.1007/s11253-024-02309-8","DOIUrl":"https://doi.org/10.1007/s11253-024-02309-8","url":null,"abstract":"<p>This descriptive text is essentially based on Sharkovsky’s and Myrberg’s publications on the ordering of periodic solutions <i>(cycles)</i> generated by a Dim 1 unimodal smooth map <i>f</i>(<i>x</i>, <i>λ</i>)<i>.</i> Taking <i>f</i>(<i>x</i>, <i>λ</i>) = <i>x</i><sup>2</sup><i>−λ</i> as an example, it was shown in a paper published in 1975 that the bifurcations are organized in the form of a sequence of <i>well-defined fractal embedded “boxes”</i> (parameter <i>λ</i> intervals) each of which is associated with a basic cycle of period <i>k</i> and a symbol <i>j</i> permitting to distinguish cycles with the same period <i>k.</i> Without using the denominations <i>Intermittency</i> (1980) and <i>Attractors in Crisis</i> (1982), this new text shows that the notion of <i>fractal embedded “boxes”</i> describes the properties of each of these two situations as the <i>limit of a sequence of well-defined boxes</i> (<i>k</i>, <i>j</i>) as <i>k</i> → ∞.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Boundary-Value Problems for Weakly Singular Integral Equations of Hammerstein Type 哈默斯坦式弱奇异积分方程的边值问题
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-07-30 DOI: 10.1007/s11253-024-02307-w
Oleksandr Boichuk, Viktor Feruk
{"title":"Boundary-Value Problems for Weakly Singular Integral Equations of Hammerstein Type","authors":"Oleksandr Boichuk, Viktor Feruk","doi":"10.1007/s11253-024-02307-w","DOIUrl":"https://doi.org/10.1007/s11253-024-02307-w","url":null,"abstract":"<p>We consider the problem of existence of the solution of a weakly nonlinear boundary-value problem for the Hammerstein-type integral equation with unbounded kernel, which turns, for <i>ε</i> = 0, into one of solutions of the generating problem. The necessary and sufficient conditions for the existence of this solution are obtained and the iterative procedure is proposed for its construction.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Application of the Second Lyapunov Method for Getting the Conditions of Stability in Systems with Quadratic Right-Hand Side 应用第二李雅普诺夫法获取具有二次右侧边的系统的稳定条件
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-30 DOI: 10.1007/s11253-024-02300-3
Denys Khusainov, Andriy Shatyrko, Bedřich Půža, Veronika Novotna
{"title":"Application of the Second Lyapunov Method for Getting the Conditions of Stability in Systems with Quadratic Right-Hand Side","authors":"Denys Khusainov, Andriy Shatyrko, Bedřich Půža, Veronika Novotna","doi":"10.1007/s11253-024-02300-3","DOIUrl":"https://doi.org/10.1007/s11253-024-02300-3","url":null,"abstract":"<p>By using the apparatus of Lyapunov’s direct method with a function from the class of quadratic forms, we establish algebraic sufficient conditions for the stability of trivial solutions to the nonlinear systems of differential equations of the second and third orders.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Dynamics of One-Dimensional Maps and Gurtin–Maccamy’s Population Model. Part I. Asymptotically Constant Solutions 一维地图动力学与古尔廷-马卡米人口模型。第一部分：渐近恒定解
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-30 DOI: 10.1007/s11253-024-02296-w
Franco Herrera, Sergei Trofimchuk
{"title":"Dynamics of One-Dimensional Maps and Gurtin–Maccamy’s Population Model. Part I. Asymptotically Constant Solutions","authors":"Franco Herrera, Sergei Trofimchuk","doi":"10.1007/s11253-024-02296-w","DOIUrl":"https://doi.org/10.1007/s11253-024-02296-w","url":null,"abstract":"<p>Motivated by the recent work by Ma and Magal [Proc. Amer. Math. Soc. (2021); https://doi.org/10.1090/proc/15629] on the global stability property of the Gurtin–MacCamy’s population model, we consider a family of scalar nonlinear convolution equations with unimodal nonlinearities. In particular, we relate the Ivanov and Sharkovsky analysis of singularly perturbed delay differential equations in [https://doi.org/10.1007/978-3-642-61243-5_5] to the asymptotic behavior of solutions of the Gurtin–MacCamy’s system. According to the classification proposed in [https://doi.org/10.1007/978-3-642-61243-5_5], we can distinguish three fundamental kinds of continuous solutions of our equations, namely, solutions of the asymptotically constant type, relaxation type, and turbulent type. We present various conditions assuring that all solutions belong to the first of these three classes. In the setting of unimodal convolution equations, these conditions suggest a generalized version of the famous Wright’s conjecture.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","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 Compartmental VSLIT Model Used to Analyze the Dynamics of Tuberculosis in Algeria and Ukraine and the Assessment of Vaccination and Treatment Effects 用于分析阿尔及利亚和乌克兰结核病动态以及评估疫苗接种和治疗效果的新型分区 VSLIT 模型
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-30 DOI: 10.1007/s11253-024-02301-2
Bouchra Chennaf, Mohammed Salah Abdelouahab, René Lozi
{"title":"A Novel Compartmental VSLIT Model Used to Analyze the Dynamics of Tuberculosis in Algeria and Ukraine and the Assessment of Vaccination and Treatment Effects","authors":"Bouchra Chennaf, Mohammed Salah Abdelouahab, René Lozi","doi":"10.1007/s11253-024-02301-2","DOIUrl":"https://doi.org/10.1007/s11253-024-02301-2","url":null,"abstract":"<p>Despite having low rates of tuberculosis (TB) mortality in many countries, like China, Europe, and the United States, some other countries, such as India continue to struggle to contain the epidemic. Our aim is to examine the effects of vaccinations and treatments on the dynamics of TB in two countries, Ukraine and Algeria, with contrasted demographic profiles. A mathematical model called the VSLIT model is considered for this purpose. The stability of both disease-free and endemic equilibrium is discussed qualitatively. For numerical simulations, the parameters are evaluated by the least-squares approach according to the TB-reported data for Algeria and Ukraine in 1990–2020.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","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 Solution Manifolds for Algebraic-Delay Systems 论代数延迟系统的求解漫域
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-30 DOI: 10.1007/s11253-024-02293-z
Hans-Otto Walther
{"title":"On the Solution Manifolds for Algebraic-Delay Systems","authors":"Hans-Otto Walther","doi":"10.1007/s11253-024-02293-z","DOIUrl":"https://doi.org/10.1007/s11253-024-02293-z","url":null,"abstract":"<p>Differential equations with state-dependent delays specify a semiflow of continuously differentiable solution operators, in general, only on an associated submanifold of the Banach space <i>C</i><sup>1</sup>([<i>−h</i>, 0],ℝ<sup><i>n</i></sup>)<i>.</i> We extend a recent result on the simplicity of these <i>solution manifolds</i> to systems in which the delay is given by the state only implicitly in an extra equation. These algebraic delay systems appear in various applications.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","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 Balanced Pantograph Equation of Mixed Type 论混合型平衡受电弓方程
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-30 DOI: 10.1007/s11253-024-02295-x
G. Derfel, B. van Brunt
{"title":"On the Balanced Pantograph Equation of Mixed Type","authors":"G. Derfel, B. van Brunt","doi":"10.1007/s11253-024-02295-x","DOIUrl":"https://doi.org/10.1007/s11253-024-02295-x","url":null,"abstract":"<p>We consider the balanced pantograph equation (BPE) <span>(y{prime}left(xright)+yleft(xright)={sum }_{k=1}^{m}{p}_{k}yleft({a}_{k}xright))</span><i>,</i> where <i>a</i><sub><i>k</i></sub><i>, p</i><sub><i>k</i></sub><i> &gt;</i> 0 and <span>({sum }_{k=1}^{m}{p}_{k}=1)</span>. It is known that if <span>(K={sum }_{k=1}^{m}{p}_{k}{text{ln}}{a}_{k}le 0)</span> then, under mild technical conditions, the BPE does not have bounded solutions that are not constant, whereas for <i>K &gt;</i> 0 these solutions exist. In the present paper, we deal with a BPE of <i>mixed type</i>, i.e., <i>a</i><sub>1</sub> <i>&lt;</i> 1 <i>&lt; a</i><sub><i>m</i></sub><i>,</i> and prove that, in this case, the BPE has a nonconstant solution <i>y</i> and that <i>y</i>(<i>x</i>) ~ <i>cx</i><sup><i>σ</i></sup> as <i>x</i> → ∞<i>,</i> where <i>c &gt;</i> 0 and <i>σ</i> is the unique positive root of the characteristic equation <span>(Pleft(sright)=1-sum_{k=1}^{m} {p}_{k}{a}_{k}^{-s}=0)</span><i>.</i> We also show that <i>y</i> is unique (up to a multiplicative constant) among the solutions of the BPE that decay to zero as <i>x</i> → ∞<i>.</i></p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Bifurcation Structure of Interval Maps with Orbits Homoclinic to a Saddle-Focus 轨道与鞍焦同轴的区间图的分岔结构
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-30 DOI: 10.1007/s11253-024-02294-y
Carter Hinsley, James Scully, Andrey L. Shilnikov
{"title":"Bifurcation Structure of Interval Maps with Orbits Homoclinic to a Saddle-Focus","authors":"Carter Hinsley, James Scully, Andrey L. Shilnikov","doi":"10.1007/s11253-024-02294-y","DOIUrl":"https://doi.org/10.1007/s11253-024-02294-y","url":null,"abstract":"<p>We study homoclinic bifurcations in an interval map associated with a saddle-focus of (2, 1)-type in ℤ<sub>2</sub>-symmetric systems. Our study of this map reveals a homoclinic structure of the saddle-focus, with bifurcation unfolding guided by the codimension-two Belyakov bifurcation. We consider three parameters of the map corresponding to the saddle quantity, splitting parameter, and the focal frequency of the smooth saddle-focus in a neighborhood of homoclinic bifurcations. We symbolically encode the dynamics of the map in order to find stability windows and locate homoclinic bifurcation sets in a computationally efficient manner. The organization and possible shapes of homoclinic bifurcation curves in the parameter space are examined, taking into account the symmetry and discontinuity of the map. Sufficient conditions for stability and local symbolic constancy of the map are presented. This study provides insights into the structure of homoclinic bifurcations of the saddle-focus map, furthering comprehension of low-dimensional chaotic systems.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
1D Piecewise Smooth Map: Exploring a Model of Investment Dynamics under Financial Frictions with Three Types of Investment Projects 1D 精确平滑地图：探索金融摩擦下三类投资项目的投资动态模型
IF 0.5 4区 数学
Ukrainian Mathematical Journal Pub Date : 2024-04-29 DOI: 10.1007/s11253-024-02299-7
Iryna Sushko, Laura Gardini, Kiminori Matsuyama
{"title":"1D Piecewise Smooth Map: Exploring a Model of Investment Dynamics under Financial Frictions with Three Types of Investment Projects","authors":"Iryna Sushko, Laura Gardini, Kiminori Matsuyama","doi":"10.1007/s11253-024-02299-7","DOIUrl":"https://doi.org/10.1007/s11253-024-02299-7","url":null,"abstract":"<p>We consider a 1D continuous piecewise smooth map, which depends on seven parameters. Depending on the values of parameters, it may have up to six branches. This map was proposed by Matsuyama [<i>Theor. Econ.</i>, <b>8</b>, 623 (2013); Sec. 5]. It describes the macroeconomic dynamics of investment and credit fluctuations in which three types of investment projects compete in the financial market. We introduce a partitioning of the parameter space according to different branch configurations of the map and illustrate this partitioning for a specific parameter setting. Then we present an example of the bifurcation structure in a parameter plane, which includes periodicity regions related to superstable cycles. Several bifurcation curves are obtained analytically; in particular, the border-collision bifurcation curves of fixed points. We show that the point of intersection of two curves of this kind is an organizing center, which serves as the origin of infinitely many other bifurcation curves.</p>","PeriodicalId":49406,"journal":{"name":"Ukrainian Mathematical Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140809755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信