SIAM Journal on Applied Mathematics最新文献_第9页

Nonlinear Monotone Energy Stability of Plane Shear Flows: Joseph or Orr Critical Thresholds? 平面剪切流的非线性单调能量稳定性：约瑟夫临界阈值还是奥尔临界阈值？

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2024-01-18 DOI: 10.1137/22m1535826

Giuseppe Mulone

{"title":"Nonlinear Monotone Energy Stability of Plane Shear Flows: Joseph or Orr Critical Thresholds?","authors":"Giuseppe Mulone","doi":"10.1137/22m1535826","DOIUrl":"https://doi.org/10.1137/22m1535826","url":null,"abstract":"SIAM Journal on Applied Mathematics, Volume 84, Issue 1, Page 60-74, February 2024. <br/> Abstract. Critical Reynolds numbers for the monotone exponential energy stability of Couette and Poiseuille plane flows were obtained by Orr in 1907 [Proc. Roy. Irish Acad. A, 27 (1907), pp. 9–68, 69–138] in a famous paper, and by Joseph in 1966 [J. Fluid Mech., 33 (1966), pp. 617–621], Joseph and Carmi in 1969 [Quart. Appl. Math., 26 (1969), pp. 575–579], and Busse in 1972 [Arch. Ration. Mech. Anal., 47 (1972), pp. 28–35]. All these authors obtained their results applying variational methods to compute the maximum of a functional ratio derived from the Reynolds–Orr energy identity. Orr and Joseph obtained different results; for instance, in the Couette case Orr computed the critical Reynolds value of 44.3 (on spanwise perturbations) and Joseph 20.65 (on streamwise perturbations). Recently in [P. Falsaperla, G. Mulone, and C. Perrone, Eur. J. Mech. B Fluids, 93 (2022), pp. 93–100], the authors conjectured that the search of the maximum should be restricted to a subspace of the space of kinematically admissible perturbations. With this conjecture, the critical nonlinear energy Reynolds number was found among spanwise perturbations (a Squire theorem for nonlinear systems). With a direct proof and an appropriate and original decomposition of the dissipation terms in the Reynolds–Orr identity we show the validity of this conjecture in the space of three-dimensional perturbations.","PeriodicalId":51149,"journal":{"name":"SIAM Journal on Applied Mathematics","volume":"39 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139499964","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

Multiplicity of Neutrally Stable Periodic Orbits with Coexistence in the Chemostat Subject to Periodic Removal Rate 恒温器中并存的中性稳定周期轨道的多重性（受周期性移除率的影响

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2024-01-16 DOI: 10.1137/23m1552450

Thomas Guilmeau, Alain Rapaport

引用次数: 0

One-Dimensional Short-Range Nearest-Neighbor Interaction and Its Nonlinear Diffusion Limit 一维短程近邻相互作用及其非线性扩散极限

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2024-01-12 DOI: 10.1137/23m155520x

Michael Fischer, Laura Kanzler, Christian Schmeiser

引用次数: 0

Combined Field-Only Boundary Integral Equations for PEC Electromagnetic Scattering Problem in Spherical Geometries 球形几何中 PEC 电磁散射问题的组合纯场边界积分方程

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2024-01-12 DOI: 10.1137/23m1561865

Luiz Maltez-Faria, Carlos Pérez-Arancibia, Catalin Turc

{"title":"Combined Field-Only Boundary Integral Equations for PEC Electromagnetic Scattering Problem in Spherical Geometries","authors":"Luiz Maltez-Faria, Carlos Pérez-Arancibia, Catalin Turc","doi":"10.1137/23m1561865","DOIUrl":"https://doi.org/10.1137/23m1561865","url":null,"abstract":"SIAM Journal on Applied Mathematics, Volume 84, Issue 1, Page 19-38, February 2024. <br/> Abstract. We analyze the well-posedness of certain field-only boundary integral equations (BIEs) for frequency domain electromagnetic scattering from perfectly conducting spheres. Starting from the observations that (1) the three components of the scattered electric field [math] and (2) scalar quantity [math] are radiative solutions of the Helmholtz equation, we see that novel boundary integral equation formulations of electromagnetic scattering from perfectly conducting obstacles can be derived using Green’s identities applied to the aforementioned quantities and the boundary conditions on the surface of the scatterer. The unknowns of these formulations are the normal derivatives of the three components of the scattered electric field and the normal component of the scattered electric field on the surface of the scatterer, and thus these formulations are referred to as field-only BIEs. In this paper we use the combined field methodology of Burton and Miller within the field-only BIE approach, and we derive new boundary integral formulations that feature only Helmholtz boundary integral operators, which we subsequently show to be well posed for all positive frequencies in the case of spherical scatterers. Relying on the spectral properties of Helmholtz boundary integral operators in spherical geometries, we show that the combined field-only boundary integral operators are diagonalizable in the case of spherical geometries and their eigenvalues are nonzero for all frequencies. Furthermore, we show that for spherical geometries one of the field-only integral formulations considered in this paper exhibits eigenvalues clustering at one—a property similar to second-kind integral equations.","PeriodicalId":51149,"journal":{"name":"SIAM Journal on Applied Mathematics","volume":"54 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459580","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

THE DIFFUSIVE ULTRASOUND MODULATED BIOLUMINESCENCE TOMOGRAPHY WITH PARTIAL DATA AND UNCERTAIN OPTICAL PARAMETERS. 具有部分数据和不确定光学参数的扩散超声调制生物发光层析成像。

IF 2 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2024-01-01 DOI: 10.1137/24m1657791

Tianyu Yang, Yang Yang

引用次数: 0

Analysis on a Spatial SIS Epidemic Model with Saturated Incidence Function in Advective Environments: I. Conserved Total Population 具有饱和发病函数的平流环境空间 SIS 流行病模型分析：I. 保持不变的总人口

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2023-12-08 DOI: 10.1137/22m1534699

Xiaodan Chen, Renhao Cui

引用次数: 0

Modeling Acoustic Space-Coiled Metacrystals 声学空间卷曲元晶体建模

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2023-12-06 DOI: 10.1137/22m1527131

Joar Zhou Hagström, Kim Pham, Agnés Maurel

引用次数: 0

Neuronal Resilience and Calcium Signaling Pathways in the Context of Synapse Loss and Calcium Leaks: A Computational MODELING Study and Implications for Alzheimer’s Disease 突触丢失和钙泄漏背景下的神经元弹性和钙信号通路:阿尔茨海默病的计算模型研究和意义

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2023-12-05 DOI: 10.1137/23m1557842

Piyush R. Borole, James M. Rosado, MeiRose Neal, Gillian Queisser

{"title":"Neuronal Resilience and Calcium Signaling Pathways in the Context of Synapse Loss and Calcium Leaks: A Computational MODELING Study and Implications for Alzheimer’s Disease","authors":"Piyush R. Borole, James M. Rosado, MeiRose Neal, Gillian Queisser","doi":"10.1137/23m1557842","DOIUrl":"https://doi.org/10.1137/23m1557842","url":null,"abstract":"SIAM Journal on Applied Mathematics, Volume 83, Issue 6, Page 2418-2442, December 2023. <br/> Abstract. In this paper, a coupled electro-calcium model was developed and implemented to computationally explore the effects of neuronal synapse loss, in particular in the context of Alzheimer’s disease. Established parameters affected by Alzheimer’s disease, such as synapse loss, calcium leaks at deteriorating synaptic contacts, and downregulation of the calcium buffer calbindin, are subject to this study. Reconstructed neurons are used to define the computational domain for a system of PDEs and ODEs, discretized by finite differences and solved with a semi-implicit second-order time integrator. The results show neuronal resilience during synapse loss. When incorporating calcium leaks at affected synapses, neurons lose their ability to produce synapse-to-nucleus calcium signals, necessary for learning, plasticity, and neuronal survival. Downregulation of calbindin concentrations partially recovers the signaling pathway to the cell nucleus. These results could define future research pathways toward stabilizing the calcium signaling pathways during Alzheimer’s disease. The coupled electro-calcium model was implemented and solved using MATLAB https://github.com/NeuroBox3D/CalcSim.","PeriodicalId":51149,"journal":{"name":"SIAM Journal on Applied Mathematics","volume":"3 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138528033","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

Design of Defected Non-hermitian Chains of Resonator Dimers for Spatial and Spatio-temporal Localizations 用于空间和时空定位的谐振器二聚体的缺陷非厄米链设计

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2023-12-05 DOI: 10.1137/23m1573896

Habib Ammari, Erik Orvehed Hiltunen, Thea Kosche

{"title":"Design of Defected Non-hermitian Chains of Resonator Dimers for Spatial and Spatio-temporal Localizations","authors":"Habib Ammari, Erik Orvehed Hiltunen, Thea Kosche","doi":"10.1137/23m1573896","DOIUrl":"https://doi.org/10.1137/23m1573896","url":null,"abstract":"SIAM Journal on Applied Mathematics, Volume 83, Issue 6, Page 2443-2468, December 2023. <br/> Abstract. The aim of this article is to advance the field of metamaterials by proposing formulas for the design of high-contrast metamaterials with prescribed subwavelength defect mode eigenfrequencies. This is achieved in two settings: (i) design of non-Hermitian static materials and (ii) design of instantly changing non-Hermitian time-dependent materials. The design of static materials is achieved via characterizing equations for the defect mode eigenfrequencies in the setting of a defected dimer material. These characterizing equations are the basis for obtaining formulas for the material parameters of the defect which admit given defect mode eigenfrequencies. Explicit formulas are provided in the setting of one and two given defect mode eigenfrequencies in the setting of a defected chain of dimers. In the time-dependent case, we first analyze the influence of time boundaries on the subwavelength solutions. We find that subwavelength solutions are preserved if and only if the material parameters satisfy a temporal Snell’s law across the time boundary. The same result also identifies the change of the time frequencies uniquely. Combining this result with those on the design of static materials, we obtain an explicit formula for the material design of instantly changing defected dimer materials which admit subwavelength modes with prescribed time-dependent defect mode eigenfrequency. Finally, we use this formula to create materials which admit spatio-temporally localized defect modes.","PeriodicalId":51149,"journal":{"name":"SIAM Journal on Applied Mathematics","volume":"71 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138527994","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

Spectral Patterns of Elastic Transmission Eigenfunctions: Boundary Localization, Surface Resonance, and Stress Concentration 弹性传输特征函数的谱图:边界局部化、表面共振和应力集中

IF 1.9 4区数学

SIAM Journal on Applied Mathematics Pub Date : 2023-12-05 DOI: 10.1137/22m1538417

Yan Jiang, Hongyu Liu, Jiachuan Zhang, Kai Zhang

引用次数: 1