IF 0.9 4区数学

Acta Mathematicae Applicatae Sinica, English Series Pub Date : 2024-11-06 DOI: 10.1007/s10255-024-1054-2

Rui-lian Du, Zhi-zhong Sun

引用次数: 0

Chaotic Motions of the van der Pol-Duffing Oscillator Subjected to Periodic External and Parametric Excitations with Delayed Feedbacks 范德尔波尔-杜芬振荡器在周期性外部和参数激励下的混沌运动与延迟反馈

IF 0.9 4区数学

Acta Mathematicae Applicatae Sinica, English Series Pub Date : 2024-11-06 DOI: 10.1007/s10255-024-1038-2

Liang-qiang Zhou, Fang-qi Chen

引用次数: 0

A Test of U-type for Goodness-of-fit in Regression Models Through Martingale Difference Divergence 通过马丁格尔差分对回归模型拟合优度的 U 型检验

IF 0.9 4区数学

Acta Mathematicae Applicatae Sinica, English Series Pub Date : 2024-11-06 DOI: 10.1007/s10255-024-1132-5

Kai Xu, Yan-qin Nie, Dao-jiang He

{"title":"A Test of U-type for Goodness-of-fit in Regression Models Through Martingale Difference Divergence","authors":"Kai Xu, Yan-qin Nie, Dao-jiang He","doi":"10.1007/s10255-024-1132-5","DOIUrl":"10.1007/s10255-024-1132-5","url":null,"abstract":"<div><p>Based on the martingale difference divergence, a recently proposed metric for quantifying conditional mean dependence, we introduce a consistent test of U-type for the goodness-of-fit of linear models under conditional mean restriction. Methodologically, our test allows heteroscedastic regression models without imposing any condition on the distribution of the error, utilizes effectively important information contained in the distance of the vector of covariates, has a simple form, is easy to implement, and is free of the subjective choice of parameters. Theoretically, our mathematical analysis is of own interest since it does not take advantage of the empirical process theory and provides some insights on the asymptotic behavior of U-statistic in the framework of model diagnostics. The asymptotic null distribution of the proposed test statistic is derived and its asymptotic power behavior against fixed alternatives and local alternatives converging to the null at the parametric rate is also presented. In particular, we show that its asymptotic null distribution is very different from that obtained for the true error and their differences are interestingly related to the form expression for the estimated parameter vector embodied in regression function and a martingale difference divergence matrix. Since the asymptotic null distribution of the test statistic depends on data generating process, we propose a wild bootstrap scheme to approximate its null distribution. The consistency of the bootstrap scheme is justified. Numerical studies are undertaken to show the good performance of the new test.</p></div>","PeriodicalId":6951,"journal":{"name":"Acta Mathematicae Applicatae Sinica, English Series","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587786","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

Characterising Cancer Cell Responses to Cyclic Hypoxia Using Mathematical Modelling. 利用数学建模描述癌细胞对周期性缺氧的反应

IF 2 4区数学

Bulletin of Mathematical Biology Pub Date : 2024-11-06 DOI: 10.1007/s11538-024-01359-0

Giulia L Celora, Ruby Nixson, Joe M Pitt-Francis, Philip K Maini, Helen M Byrne

{"title":"Characterising Cancer Cell Responses to Cyclic Hypoxia Using Mathematical Modelling.","authors":"Giulia L Celora, Ruby Nixson, Joe M Pitt-Francis, Philip K Maini, Helen M Byrne","doi":"10.1007/s11538-024-01359-0","DOIUrl":"10.1007/s11538-024-01359-0","url":null,"abstract":"<p><p>In vivo observations show that oxygen levels in tumours can fluctuate on fast and slow timescales. As a result, cancer cells can be periodically exposed to pathologically low oxygen levels; a phenomenon known as cyclic hypoxia. Yet, little is known about the response and adaptation of cancer cells to cyclic, rather than, constant hypoxia. Further, existing in vitro models of cyclic hypoxia fail to capture the complex and heterogeneous oxygen dynamics of tumours growing in vivo. Mathematical models can help to overcome current experimental limitations and, in so doing, offer new insights into the biology of tumour cyclic hypoxia by predicting cell responses to a wide range of cyclic dynamics. We develop an individual-based model to investigate how cell cycle progression and cell fate determination of cancer cells are altered following exposure to cyclic hypoxia. Our model can simulate standard in vitro experiments, such as clonogenic assays and cell cycle experiments, allowing for efficient screening of cell responses under a wide range of cyclic hypoxia conditions. Simulation results show that the same cell line can exhibit markedly different responses to cyclic hypoxia depending on the dynamics of the oxygen fluctuations. We also use our model to investigate the impact of changes to cell cycle checkpoint activation and damage repair on cell responses to cyclic hypoxia. Our simulations suggest that cyclic hypoxia can promote heterogeneity in cellular damage repair activity within vascular tumours.</p>","PeriodicalId":9372,"journal":{"name":"Bulletin of Mathematical Biology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11541430/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142582360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Topology optimization design of labyrinth seal-type devices considering subsonic compressible turbulent flow conditions 考虑亚音速可压缩湍流条件的迷宫式密封装置拓扑优化设计

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-11-06 DOI: 10.1016/j.camwa.2024.10.029

Luís F.N. Sá , Felipe Silva Maffei , Lucas N.B.S. Ribeiro , Julio Romano Meneghini , Emílio Carlos Nelli Silva

{"title":"Topology optimization design of labyrinth seal-type devices considering subsonic compressible turbulent flow conditions","authors":"Luís F.N. Sá , Felipe Silva Maffei , Lucas N.B.S. Ribeiro , Julio Romano Meneghini , Emílio Carlos Nelli Silva","doi":"10.1016/j.camwa.2024.10.029","DOIUrl":"10.1016/j.camwa.2024.10.029","url":null,"abstract":"<div><div>In this work, a topology optimization model for designing devices that operate with multiple relative velocities considering turbulent compressible flows is proposed. The model consists of the Favre-averaged Navier-stokes equations in an axisymmetric domain coupled with a continuous boundary propagation model. The propagation is used to impose different solid behaviors based on which wall it is connected to, for example, solid material in contact with a rotating shaft will have a rotational velocity, while material encrusted in the support will have zero absolute velocity. The implementation is composed of a segregated solver with steps for the FANS equations, the <span><math><mi>k</mi><mo>−</mo><mi>ϵ</mi></math></span> turbulent equations, and the propagation model. The sensitivity is obtained with automatic differentiation of the adjoint method and an internal point optimizer is used to update the design variable. A study case of a labyrinth seal is defined to illustrate the methodology by using three different objective functions, maximization of radial velocity, static pressure change rate, and vorticity. The results are designs for small-scale labyrinth seals in real operation conditions.</div></div>","PeriodicalId":55218,"journal":{"name":"Computers & Mathematics with Applications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Fine profiles of positive solutions for some nonlocal dispersal equations 某些非局部分散方程正解的精细轮廓

IF 2.4 2区数学

Journal of Differential Equations Pub Date : 2024-11-06 DOI: 10.1016/j.jde.2024.10.038

Yan-Hua Xing, Jian-Wen Sun

引用次数: 0

Refining a chain theorem from matroids to internally 4-connected graphs 完善从矩阵到内部 4 连接图的链式定理

IF 1 3区数学

Advances in Applied Mathematics Pub Date : 2024-11-06 DOI: 10.1016/j.aam.2024.102802

Chanun Lewchalermvongs , Guoli Ding

引用次数: 0

Normalized solutions to HLS upper critical focusing Choquard equation with a non-autonomous nonlocal perturbation 具有非自主非局部扰动的 HLS 上临界聚焦 Choquard 方程的归一化解

IF 1.4 3区数学

Analysis and Mathematical Physics Pub Date : 2024-11-05 DOI: 10.1007/s13324-024-00979-y

Ziheng Zhang, Jianlun Liu, Hong-Rui Sun

{"title":"Normalized solutions to HLS upper critical focusing Choquard equation with a non-autonomous nonlocal perturbation","authors":"Ziheng Zhang, Jianlun Liu, Hong-Rui Sun","doi":"10.1007/s13324-024-00979-y","DOIUrl":"10.1007/s13324-024-00979-y","url":null,"abstract":"<div><p>This paper is concerned with the following HLS upper critical focusing Choquard equation with a non-autonomous nonlocal perturbation </p><div><div><span>$$begin{aligned} {left{ begin{array}{ll} -{Delta }u-mu (I_alpha *[h|u|^p])h|u|^{p-2}u-(I_alpha *|u|^{2^*_alpha })|u|^{2^*_alpha -2}u=lambda u text{ in } mathbb {R}^N, int _{mathbb {R}^N} u^2 dx = c, end{array}right. } end{aligned}$$</span></div></div><p>where <span>(mu ,c>0)</span>, <span>(N ge 3)</span>, <span>(0<alpha <N)</span>, <span>(2_alpha :=frac{N+alpha }{N}<p<2^*_alpha :=frac{N+alpha }{N-2})</span>, <span>(lambda in mathbb {R})</span> is a Lagrange multiplier, <span>(I_alpha )</span> is the Riesz potential and <span>(h:mathbb {R}^Nrightarrow (0,infty ))</span> is a continuous function. Under a class of reasonable assumptions on <i>h</i>, we prove the existence of normalized solutions to the above problem for the case <span>(frac{N+alpha +2}{N}le p<frac{N+alpha }{N-2})</span> and discuss its asymptotical behaviors as <span>(mu rightarrow 0^+)</span> and <span>(crightarrow 0^+)</span> respectively. When <span>(frac{N+alpha }{N}<p<frac{N+alpha +2}{N})</span>, we obtain the existence of one local minimizer after considering a suitable minimization problem.</p></div>","PeriodicalId":48860,"journal":{"name":"Analysis and Mathematical Physics","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587740","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 quantization of Maxwell theory in the Cauchy radiation gauge: Hodge decomposition and Hadamard states 考奇辐射规中麦克斯韦理论的量子化：霍奇分解与哈达玛态

IF 1 2区数学

Journal of the London Mathematical Society-Second Series Pub Date : 2024-11-05 DOI: 10.1112/jlms.70020

Simone Murro, Gabriel Schmid

引用次数: 0

Stefan Heinrich is the Winner of the 2024 Best Paper Award of the Journal of Complexity 斯特凡-海因里希荣获《复杂性期刊》2024 年度最佳论文奖

IF 1.8 2区数学

Journal of Complexity Pub Date : 2024-11-05 DOI: 10.1016/j.jco.2024.101905

Erich Novak, Mario Ullrich, Jan Vybíral

引用次数: 0

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