AIMS Mathematics最新文献

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Characterizations of modules definable in o-minimal structures 0 -极小结构中可定义模块的刻画
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023660
Jaruwat Rodbanjong, Athipat Thamrongthanyalak
{"title":"Characterizations of modules definable in o-minimal structures","authors":"Jaruwat Rodbanjong, Athipat Thamrongthanyalak","doi":"10.3934/math.2023660","DOIUrl":"https://doi.org/10.3934/math.2023660","url":null,"abstract":"Let $ mathfrak M $ be an o-minimal expansion of a densely linearly ordered set and $ (S, +, cdot, 0_S, 1_S) $ be a ring definable in $ mathfrak M $. In this article, we develop two techniques for the study of characterizations of $ S $-modules definable in $ mathfrak M $. The first technique is an algebraic technique. More precisely, we show that every $ S $-module definable in $ mathfrak M $ is finitely generated. For the other technique, we prove that every $ S $-module definable in $ mathfrak M $ admits a unique definable $ S $-module manifold topology. As consequences, we obtain the following: (1) if $ S $ is finite, then a module $ A $ is isomorphic to an $ S $-module definable in $ mathfrak M $ if and only if $ A $ is finite; (2) if $ S $ is an infinite ring without zero divisors, then a module $ A $ is isomorphic to an $ S $-module definable in $ mathfrak M $ if and only if $ A $ is a finite dimensional free module over $ S $; and (3) if $ mathfrak M $ is an expansion of an ordered divisible abelian group and $ S $ is an infinite ring without zero divisors, then every $ S $-module definable in $ mathfrak M $ is definably connected with respect to the unique definable $ S $-module manifold topology.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70196799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 1
Generalized first-order second-moment method for uncertain random structures 不确定随机结构的广义一阶二阶矩法
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023682
Yubing Chen, M. Wen, Qingyuan Zhang, Yu Zhou, Rui Kang
{"title":"Generalized first-order second-moment method for uncertain random structures","authors":"Yubing Chen, M. Wen, Qingyuan Zhang, Yu Zhou, Rui Kang","doi":"10.3934/math.2023682","DOIUrl":"https://doi.org/10.3934/math.2023682","url":null,"abstract":"In this paper, a new reliability assessing method for structures influenced by both aleatory and epistemic uncertainty simultaneously is developed. To handle hybrid types of uncertainties, chance theory is introduced to define a new hybrid reliability index. By mathematical derivation and theorems proofs, the new index is showed to be effective and compatible with hybrid types of uncertainties. Correspondingly, a generalized first-order second-moment (GFOSM) algorithm is established for practical reliability assessment of structures with hybrid uncertainties. Based on the first two moments of basic variables, the GFOSM method can perform fast and effective reliability assessment without large-scale integration operations and can be considered as an extension and expansion of the traditional FOSM method. Two numerical cases further illustrate the effectiveness and practicability of the proposed method from different perspectives.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70197813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Two discrete Mittag-Leffler extensions of the Cayley-exponential function cayley指数函数的两个离散Mittag-Leffler扩展
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023687
T. Abdeljawad
{"title":"Two discrete Mittag-Leffler extensions of the Cayley-exponential function","authors":"T. Abdeljawad","doi":"10.3934/math.2023687","DOIUrl":"https://doi.org/10.3934/math.2023687","url":null,"abstract":"Nabla discrete fractional Mittag-Leffler (ML) functions are the key of discrete fractional calculus within nabla analysis since they extend nabla discrete exponential functions. In this article, we define two new nabla discrete ML functions depending on the Cayley-exponential function on time scales. While, the nabla discrete ML function $ E_{overline{gamma}} (lambda, t) $ converges for $ |lambda| < 1 $, both of the defined discrete functions converge for more relaxed $ lambda $. The nabla discrete Laplace transforms of the newly defined functions are calculated and confirmed as well. Some illustrative graphs for the two extensions are provided.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70198163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 new fourth-order grouping iterative method for the time fractional sub-diffusion equation having a weak singularity at initial time 一种新的四阶分组迭代法求解具有弱初始奇异性的时间分数次扩散方程
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023697
Muhammad Asim Khan, N. Alias, Umair Ali
{"title":"A new fourth-order grouping iterative method for the time fractional sub-diffusion equation having a weak singularity at initial time","authors":"Muhammad Asim Khan, N. Alias, Umair Ali","doi":"10.3934/math.2023697","DOIUrl":"https://doi.org/10.3934/math.2023697","url":null,"abstract":"A new fourth-order explicit grouping iterative method is constructed for the numerical solution of the fractional sub-diffusion equation. The discretization of the equation is based on fourth-order finite difference method. Captive fractional discretization having functions with a weak singularity at $ t = 0 $ is used for time and similarly, the space derivative is approximated with the help of fourth-order approximation. Furthermore, the convergence and stability of the scheme are analyzed. Finally, the accuracy and validity are investigated by some numerical examples.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70198231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 3
Adaptive estimation for spatially varying coefficient models 空间变系数模型的自适应估计
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023713
Heng Liu, Xia Cui
{"title":"Adaptive estimation for spatially varying coefficient models","authors":"Heng Liu, Xia Cui","doi":"10.3934/math.2023713","DOIUrl":"https://doi.org/10.3934/math.2023713","url":null,"abstract":"In this paper, a new adaptive estimation approach is proposed for the spatially varying coefficient models with unknown error distribution, unlike geographically weighted regression (GWR) and local linear geographically weighted regression (LL), this method can adapt to different error distributions. A generalized Modal EM algorithm is presented to implement the estimation, and the asymptotic property of the estimator is established. Simulation and real data results show that the gain of the new adaptive method over the GWR and LL estimation is considerable for the error of non-Gaussian distributions.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70198878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Modeling the role of public health intervention measures in halting the transmission of monkeypox virus 模拟公共卫生干预措施在阻止猴痘病毒传播方面的作用
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023723
R. T. Alqahtani, S. Musa, M. Inc.
{"title":"Modeling the role of public health intervention measures in halting the transmission of monkeypox virus","authors":"R. T. Alqahtani, S. Musa, M. Inc.","doi":"10.3934/math.2023723","DOIUrl":"https://doi.org/10.3934/math.2023723","url":null,"abstract":"Monkeypox (mpox), a zoonotic viral disease caused by the monkeypox virus (mpoxv), is endemic in many countries in West Africa and is sometimes exported to other parts of the world. The recent outbreak of mpoxv in humans, in endemic and non-endemic countries, has created substantial public health concern worldwide. This research uses a mechanistic model to study the transmission dynamics of mpoxv epidemics in the USA. Our model describes the interaction between different categories of individuals represent various infection phases and hospitalization processes. The model also takes into account the extent of compliance with non-pharmaceutical intervention strategies (NPIs), such as using condoms during sexual contact, quarantine and avoiding large gatherings. The model's equilibria are analyzed, and results on asymptotic stability are obtained. Moreover, the basic reproductive number and other threshold quantities are used to establish the conditions for a forward or backward bifurcation. Our model accurately captures the incidence curves from mpox surveillance data for the USA, indicating that it can be used to explain mpoxv transmission and suggest some effective ways to enhance control efforts. In addition, numerical simulations are carried out to examine the influence of some parameters on the overall dynamics of the model. A partial rank correlation coefficient is adopted for the sensitivity analysis to determine the model most important parameters, which require close attention for effective mpoxv prevention and control. We conclude that it is especially important to ensure that NPIs are properly followed to mitigate mpoxv outbreaks effectively.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70199225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Threshold dynamics of a nonlocal diffusion West Nile virus model with spatial heterogeneity 具有空间异质性的西尼罗病毒非局部扩散模型的阈值动力学
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023729
Kangkang Chang, Zhenyu Zhang, Guizhen Liang
{"title":"Threshold dynamics of a nonlocal diffusion West Nile virus model with spatial heterogeneity","authors":"Kangkang Chang, Zhenyu Zhang, Guizhen Liang","doi":"10.3934/math.2023729","DOIUrl":"https://doi.org/10.3934/math.2023729","url":null,"abstract":"In this study, we investigated the threshold dynamics of a spatially heterogeneous nonlocal diffusion West Nile virus model. By employing semigroup theory and continuous Fréchet-differentiable, we established the well-posedness of the solution. The expression for the basic reproduction number derived using the next-generation matrix method. The authors demonstrated the threshold dynamics of the system by constructing a Lyapunov function and applying the comparison principle. Finally, numerical simulations were used to validate the theorem results. It can be suggested that to control disease development rapidly, measures should be taken to reduce the spread of mosquitoes and birds.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70199310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 1
A strategy for hepatitis diagnosis by using spherical $ q $-linear Diophantine fuzzy Dombi aggregation information and the VIKOR method 基于球面q -线性丢番图模糊Dombi聚集信息和VIKOR方法的肝炎诊断策略
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023735
Huzaira Razzaque, Shahzaib Ashraf, Wajdi Kallel, Muhammad Naeem, Muhammad Sohail
{"title":"A strategy for hepatitis diagnosis by using spherical $ q $-linear Diophantine fuzzy Dombi aggregation information and the VIKOR method","authors":"Huzaira Razzaque, Shahzaib Ashraf, Wajdi Kallel, Muhammad Naeem, Muhammad Sohail","doi":"10.3934/math.2023735","DOIUrl":"https://doi.org/10.3934/math.2023735","url":null,"abstract":"Hepatitis is an infectious disease typified by inflammation in internal organ tissues, and it is caused by infection or inflammation of the liver. Hepatitis is often feared as a fatal illness, especially in developing countries, mostly due to contaminated water, poor sanitation, and risky blood transfusion practices. Although viruses are typically blamed, other potential causes of this kind of liver infection include autoimmune disorders, toxins, medicines, opioids, and alcohol. Viral hepatitis may be diagnosed using a variety of methods, including a physical exam, liver surgery (biopsy), imaging investigations like an ultrasound or CT scan, blood tests, a viral serology panel, a DNA test, and viral antibody testing. Our study proposes a new decision-support system for hepatitis diagnosis based on spherical q-linear Diophantine fuzzy sets (Sq-LDFS). Sq-LDFS form the generalized structure of all existing notions of fuzzy sets. Furthermore, a list of novel Einstein aggregation operators is developed under Sq-LDF information. Also, an improved VIKOR method is presented to address the uncertainty in analyzing the viral hepatitis categories demonstration. Interesting and useful properties of the proposed operators are given. The core of this research is the proposed algorithm based on the proposed Einstein aggregation operators and improved VIKOR approach to address uncertain information in decision support problems. Finally, a hepatitis diagnosis case study is examined to show how the suggested approach works in practice. Additionally, a comparison is provided to demonstrate the superiority and efficacy of the suggested decision technique.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70199862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 4
A cascade dead-zone extended state observer for a class of systems with measurement noise 一类具有测量噪声系统的级联死区扩展状态观测器
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023732
Shihua Zhang, Xiaohui Qi, Sen Yang
{"title":"A cascade dead-zone extended state observer for a class of systems with measurement noise","authors":"Shihua Zhang, Xiaohui Qi, Sen Yang","doi":"10.3934/math.2023732","DOIUrl":"https://doi.org/10.3934/math.2023732","url":null,"abstract":"For high frequency noise, a new $ 2n $-th order cascade extended state observer with dynamic dead-zone structure is proposed in this paper. Dead zone dynamic consists of two parts. One is to \"trim\" the effect of noise by cutting off the part that falls in the dead zone. The other part pushes the dead zone amplitude to converge to 0 as soon as possible to ensure the convergence of the estimation error. Moreover, in the cascade structure, the high-gain parameter grows only to a second power, thus avoiding excessive amplification of the measurement noise and solving numerical implementation problems. The design procedure ensures that the extended state observer is input-to-state stable. Numerical simulations show the improvement in terms of total disturbance estimation and noise attenuation. The frequency-domain analysis of the proposed ESO using the describing function method investigates the effect of the dead zone nonlinear parameter on the performance of a closed-loop system.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70199900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
The connection between ordinary and soft $ sigma $-algebras with applications to information structures 普通代数与软代数之间的联系及其在信息结构中的应用
IF 2.2 3区 数学
AIMS Mathematics Pub Date : 2023-01-01 DOI: 10.3934/math.2023759
T. Al-shami, Z. Ameen, A. Mhemdi
{"title":"The connection between ordinary and soft $ sigma $-algebras with applications to information structures","authors":"T. Al-shami, Z. Ameen, A. Mhemdi","doi":"10.3934/math.2023759","DOIUrl":"https://doi.org/10.3934/math.2023759","url":null,"abstract":"The paper presents a novel analysis of interrelations between ordinary (crisp) $ sigma $-algebras and soft $ sigma $-algebras. It is known that each soft $ sigma $-algebra produces a system of crisp (parameterized) $ sigma $-algebras. The other way round is also possible. That is to say, one can generate a soft $ sigma $-algebra from a system of crisp $ sigma $-algebras. Different methods of producing soft $ sigma $-algebras are discussed by implementing two formulas. It is demonstrated how these formulas can be used in practice with the aid of some examples. Furthermore, we study the fundamental properties of soft $ sigma $-algebras. Lastly, we show that elements of a soft $ sigma $-algebra contain information about a specific event.","PeriodicalId":48562,"journal":{"name":"AIMS Mathematics","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70200931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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: 3
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