检索结果-内蒙古大学图书馆

On well-posedness of integro-differential equations in weighted L²-Spaces

Differential and Integral Equations 1995年第3期8卷 627-646页

作者： Burns, John A. Ito, Kazufumi Kappel, Franz Interdisciplinary Center for Applied Mathematics Department of Mathematics Virginia Polytechnic Institute and State University Blacksburg VA 24061 United States Center for Research in Scientific Computing Department of Mathematics North Carolina State University Raleigh NC 27695 United States

In this paper we consider the problem of constructing a well-posed state space model for a class of singular integro-differential equations of neutral type. The work is motivated by the need to develop a framework for the analysis of numerical methods for designing control laws for aeroelastic systems. Semigroup theory is used to establish existence and well-posedness results for initial data in weighted L²spaces. It is shown that these spaces lead naturally to the dissipativeness of the basic dynamic operator. The dissipativeness of the solution generator combined with the Hilbert space structure of these weighted spaces make this choice of a state space more suitable for use in the design of computational methods for control than previously used product spaces. © 1995, Khayyam Publishing.

关键词： 34K40 45K05 47N20

来源：评论

学校读者我要写书评

暂无评论

Spatial segregation in stage-structured populations with an application to Tribolium

引用

Journal of Biological Dynamics 2011年第5期5卷 398-409页

作者： Robertson, Suzanne L. Cushing, J.M. Interdisciplinary Program in Applied Mathematics University of Arizona Tucson AZ 85721 United States Department of Mathematics University of Arizona Tucson AZ 85721 United States Mathematical Biosciences Institute The Ohio State University Columbus OH 43210 United States

Spatial segregation among life-cycle stages has been observed in many stage-structured species, including species of the flour beetle Tribolium. We investigate density-dependent dispersal of life-cycle stages as a possible mechanism responsible for this separation. We explore this hypothesis using stage-structured, integrodifference equation (IDE) models that incorporate density-dependent dispersal kernels. We first investigate mechanisms that can lead to spatial patterns in juvenile-adult IDE models. We show, via numerical simulation, that density-dependent dispersal can lead to the spatial segregation of life-cycle stages in the sense that each stage peaks in a different spatial location. We then construct a three-stage spatial model to describe the population dynamics of Tribolium castaneum and Tribolium confusum and assess density-dependent dispersal mechanisms that are able to explain spatial patterns that have been experimentally observed in these species. © 2011 Taylor & Francis.

关键词： Density-dependent dispersal Integrodifference equations Population dynamics Segregation of life-cycle stages Spatial patterns

来源：评论

学校读者我要写书评

暂无评论

Ultradense Sphere Packings Derived From Disordered Stealthy Hyperuniform Ground States

arXiv

引用

arXiv 2025年

作者： Kim, Jaeuk Torquato, Salvatore Princeton Materials Institute Department of Physics Department of Chemistry Princeton University PrincetonNJ08544 United States Department of Chemistry Department of Physics Princeton Materials Institute Program in Applied and Computational Mathematics Princeton University PrincetonNJ08544 United States

Disordered stealthy hyperuniform (SHU) packings are an emerging class of exotic amorphous two-phase materials endowed with novel optical, transport, and mechanical properties. Such packings of identical spheres have been created from SHU ground-state point patterns via a modified collective-coordinate optimization scheme that includes a soft-core repulsion, besides the standard "stealthy" pair potential. To explore maximal ranges of the packing fraction , we investigate the distributions of minimum pair distances as well as nearest-neighbor distances of ensembles of SHU point patterns without and with soft-core repulsions in the first three space dimensions as a function of the stealthiness parameter χ and number of particles N within a hypercubic simulation box under periodic boundary conditions. Within the disordered regime (χ max(χ, d), decrease to zero on average as N increases if there are no soft-core repulsions. By contrast, the inclusion of soft-core repulsions results in very large max(χ, d) independent of N, reaching up to max(χ, d) = 1.0, 0.86, 0.63 in the zero-χ limit and decreasing to max(χ, d) = 1.0, 0.67, 0.47 at χ = 0.45 for d = 1, 2, 3, respectively. We obtain explicit formulas for max(χ, d) as functions of χ and N for a given value of d in both cases with and without soft-core repulsions. In two and three dimensions, our soft-core SHU ground-state packings for small χ become configurationally very close to the corresponding jammed hard-particle packings created by fast compression algorithms, as measured by their pair statistics. As χ increases beyond 0.20, the packings form fewer contacts and linear polymer-like chains as χ tends to 1/2. The resulting structure factors S(k) and pair correlation functions g2(r) reveal that soft-core repulsions significantly alter the short- and intermediate-range correlations in the SHU ground states. We show that the degree of large-scale order of the soft-core SHU ground states increases as χ increases from 0 to

关键词： Digital arithmetic

来源：评论

学校读者我要写书评

暂无评论

Distributing pairs of vertices on Hamiltonian cycles

引用

Science China mathematics 2018年第5期61卷 955-972页

作者： Weihua He Hao Li Qiang Sun Department of Applied Mathematics Guangdong University of Technology Laboratoire de Recherche en Informatique CNRS-Université Paris-Sud Institute for Interdisciplinary Research Jianghan University School of Mathematical Science Yangzhou University

Let G be a graph of order n with minimum degree δ(G)≥n/2+1. Faudree and Li(2012) conjectured that for any pair of vertices x and y in G and any integer 2≤k≤n/2, there exists a Hamiltonian cycle C such that the distance between x and y on C is k. In this paper, we prove that this conjecture is true for graphs of sufficiently large order. The main tools of our proof are the regularity lemma of Szemer′edi and the blow-up lemma of Koml′os et al.(1997).

关键词： Hamiltonian cycle Faudree-Li conjecture regularity lemma blow-up lemma

来源：评论

学校读者我要写书评

暂无评论

The split common fixed point problem for infinite families of demicontractive mappings

引用

Fixed Point Theory and Applications 2018年第1期2018卷 1-21页

作者： Hanjing, Adisak Suantai, Suthep Ph.D. Degree Program in Mathematics Faculty of Science Chiang Mai University Chiang Mai Thailand Center of Excellence in Mathematics and Applied Mathematics Department of Mathematics Faculty of Science Chiang Mai University Chiang Mai Thailand Center of Excellence in Mathematics CHE Bangkok Thailand

In this paper, we propose a new algorithm for solving the split common fixed point problem for infinite families of demicontractive mappings. Strong convergence of the proposed method is established under suitable control conditions. We apply our main results to study the split common null point problem, the split variational inequality problem, and the split equilibrium problem in the framework of a real Hilbert space. A numerical example supporting our main result is also given. © 2018, The Author(s).

关键词： Demicontractive mappings Equilibrium problem Fixed point problem Null point problem Variational inequality problem

来源：评论

学校读者我要写书评

暂无评论

Innovation and utilization of coffee skin waste (Coffea robusta L) as a superior compost for the growth of pepper cuttings (Piper nigrum L.)

引用

AIP Conference Proceedings 2025年第1期3186卷

作者： Awalul Fatiqin Dewi Lestari R. A. Hoetary Tirta Amalia Riri Novita Sunarti Ike Apriani Anita Restu Puji Raharjeng Rr Mini Sari Wulan Thathit Suprayogi Yahya Febrianto Sudarman Rahman Shesanthi Citrariana Rokiy Alfanaar Mu’afa Purwa Arsana Yithro Serang Wansadaj Jaroenram Biology Study Program Faculty of Mathematics and Natural Sciences Palangka Raya University Palangka Raya Central Kalimantan Indonesia Biology Study Program Faculty of Science and Technology Universitas Islam Negeri Raden Fatah Palembang Palembang South Sumatra Indonesia Education Biology Study Program Faculty of Teacher Training and Education Universitas Islam Negeri Raden Fatah Palembang Palembang South Sumatra Indonesia Physics Study Program Faculty of Mathematics and Natural Sciences Palangka Raya University Palangka Raya Central Kalimantan Indonesia Pharmacy Study Program Faculty of Mathematics and Natural Sciences Palangka Raya University Palangka Raya Central Kalimantan Indonesia Chemistry Study Program Faculty of Mathematics and Natural Sciences Palangka Raya University Palangka Raya Central Kalimantan Indonesia Mathematics Study Program Faculty of Mathematics and Natural Sciences Palangka Raya University Palangka Raya Central Kalimantan Indonesia Department of applied chemistry Chaoyang University of Technology Taichung City Taiwan National center for genetic engineering and biotechnology (BIOTEC) Pathum Thani Thailand

This study aimed to determine the potential of coffee skin waste (Coffea robusta L) as a superior compost innovation for the growth of pepper-cutting seedlings (Piper nigrum L). This study used an experimental method with a completely randomized design using five treatments and five repeats, variations in the dose of coffee skin waste used P0 (control), P1 (90 g), P2 (135 g), P3 (180 g), and P4 (225 g). The shoot height, number of leaves, number of roots, and length of roots were measured. The results showed that coffee skin waste compost significantly affected shoot height, especially at P1 (90 g), resulting in an average growth height of 7.24 cm. In addition, the highest number of leaves was found at a concentration of P1 (90 g), with an average of two leaves. Although there was no significant effect on the number of roots, the concentration of P1 (90 g) yielded the best results, with an average of 33 root blades, and the best root length was obtained at the concentration of P1 (90 g), with an average of 44.6 cm. Therefore, coffee skin waste significantly influenced shoot height and the number of leaves on pepper-cut seedlings (Piper nigrum L.) in the P1 treatment (90 g).

关键词：

来源：评论

学校读者我要写书评

暂无评论

THE EVOLUTION OF DISTURBANCES IN AN EKMAN BOUNDARY-LAYER

引用

JOURNAL OF FLUID MECHANICS 1982年第FEB期115卷 327-346页

作者： SPOONER, GF CRIMINALE, WO Department of Oceanography University of Washington Seattle Washington 98195 U.S.A. Also at Applied Mathematics Group Geophysics Program University of Washington Seattle.

A linear model of a wave packet in a laminar Ekman boundary layer is proposed for tracing the development of an initially localized pulsed perturbation at the boundary. The model disturbance was built up from a linear combination of growing modes summed numerically over all wavenumbers and frequencies. The input spectrum was assumed to be flat so that there was no biasing at any wavenumber or frequency and the evolution was calculated on the basis of linear-stability theory. The wave packet generated by the summation of modes developed uniformly downstream of the disturbance source location and, depending upon the choice of the Reynolds number, vividly displayed results representative of the different kinds of instabilities that are present in the Ekman layer. Outputs in the form of perspective plots are given in order to explain the evolution of the packet into either a single wave patch or a sum of individual wave patches.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Differentiable Simulator For Dynamic & Stochastic Optimal Gas & Power Flows 63

Differentiable Simulator For Dynamic & Stochastic Optimal Ga...

引用

63rd IEEE Conference on Decision and Control, CDC 2024

作者： Hyett, Criston Pagnier, Laurent Alisse, Jean Goldshtein, Igal Saban, Lilah Ferrando, Robert Chertkov, Michael University of Arizona Program in Applied Mathematics & Department of Mathematics TucsonAZ United States Noga the Israel Independent System Operator Haifa Israel

ISBN: (纸本)9798350316339

In many power systems, particularly those isolated from larger intercontinental grids, reliance on natural gas is crucial. This dependence becomes particularly critical during periods of volatility or scarcity in renewable energy sources, further complicated by unpredictable consumption trends. To ensure the uninterrupted operation of these isolated gas-grid systems, innovative and efficient management strategies are essential. This paper investigates the complexities of achieving synchronized, dynamic, and stochastic optimization for autonomous transmission-level gas-grid infrastructures. We introduce a novel methodology grounded in differentiable programming, which synergizes symbolic programming, a conservative numerical method for solving gas-flow partial differential equations, and automated sensitivity analysis powered by SciML/Julia. Our methodology refines the co-optimization landscape for gas-grid systems by grounding gas dynamics in physics-adherent simulation. We demonstrate efficiency and precision of the methodology by solving a stochastic optimal gas flow problem, phrased on an open source model of Israel's gas grid model. © 2024 IEEE.

关键词： Sensitivity analysis

来源：评论

学校读者我要写书评

暂无评论

Novel Scheme for Robust Confusion Component Selection Based on Pythagorean Fuzzy Set

引用

Computers, Materials & Continua 2023年第3期74卷 6523-6534页

作者： Nabilah Abughazalah Mohsin Iqbal Majid Khan Iqtadar Hussain Department of Mathematical Sciences College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Mathematics&Statistics Riphah International UniversityIslamabadPakistan Department of Applied Mathematics&Statistics Institute of Space TechnologyIslamabadPakistan Mathematics Program Department of MathematicsStatistics and PhysicsCollege of Arts and SciencesQatar University2713DohaQatar Statistical Consulting Unit College of Arts and ScienceQatar UniversityDohaQatar

The substitution box,often known as an S-box,is a nonlinear component that is a part of several block *** purpose is to protect cryptographic algorithms from a variety of cryptanalytic assaults.A Multi-Criteria Decision Making(MCDM)problem has a complex selection procedure because of having many options and criteria to choose *** of this,statistical methods are necessary to assess the performance score of each S-box and decide which option is the best one available based on this *** the Pythagorean Fuzzy-based Technique for Order of Preference by Similarity to Ideal Solution(TOPSIS)method,the major objective of this investigation is to select the optimal S-box to be implemented from a pool of twelve key *** the help of the Pythagorean fuzzy set(PFS),the purpose of this article is to evaluate whether this nonlinear component is suitable for use in a variety of encryption *** this article,we have considered various characteristics of S-boxes,including nonlinearity,algebraic degree,strict avalanche criterion(SAC),absolute indicator,bit independent criterion(BIC),sum of square indicator,algebraic immunity,transparency order,robustness to differential cryptanalysis,composite algebraic immunity,signal to noise ratio-differential power attack(SNR-DPA),and confusion coefficient variance on some standard S-boxes that are Advanced Encryption Following this,the findings of the investigation are changed into Pythagorean fuzzy numbers in the shape of a *** matrix is then subjected to an analysis using the TOPSIS method,which is dependent on the Pythagorean fuzzy set,to rank the most suitable S-box for use in encryption applications.

关键词： Decision making substitution box TOPSIS multi-criterion decision making fuzzy set Pythagorean fuzzy set

来源：评论

学校读者我要写书评

暂无评论

Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields 1

引用

丛书名： applied Mathematical Sciences

1983年

作者： John Guckenheimer Philip Holmes

ISBN: (数字)9781461211402

ISBN: (纸本)9780387908199;9781461270201

"This book is concerned with the application of methods from dynamical systems and bifurcation theories to the study of nonlinear oscillations. Chapter 1 provides a review of basic results in the theory of dynamical systems, covering both ordinary differential equations and discrete mappings. Chapter 2 presents 4 examples from nonlinear oscillations. Chapter 3 contains a discussion of the methods of local bifurcation theory for flows and maps, including center manifolds and normal forms. Chapter 4 develops analytical methods of averaging and perturbation theory. Close analysis of geometrically defined two-dimensional maps with complicated invariant sets is discussed in chapter 5. Chapter 6 covers global homoclinic and heteroclinic bifurcations. The final chapter shows how the global bifurcations reappear in degenerate local bifurcations and ends with several more models of physical problems which display these behaviors." #;#1 "An attempt to make research tools concerning `strange attractors' developed in the last 20 years available to applied scientists and to make clear to research mathematicians the needs in applied works. Emphasis on geometric and topological solutions of differential equations. Applications mainly drawn from nonlinear oscillations." #;#2

关键词： Analysis

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：