Mathematics and Computers in Simulation最新文献_第6页

Numerical study of vector solitons with the oscillatory phase backgrounds in the integrable coupled nonlinear Schrödinger equations 可积分耦合非线性薛定谔方程中具有振荡相位背景的矢量孤子的数值研究

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-20 DOI: 10.1016/j.matcom.2024.09.009

Lei Liu , Xuan-Xuan Zhou , Xi-Yang Xie , Wen-Rong Sun

{"title":"Numerical study of vector solitons with the oscillatory phase backgrounds in the integrable coupled nonlinear Schrödinger equations","authors":"Lei Liu , Xuan-Xuan Zhou , Xi-Yang Xie , Wen-Rong Sun","doi":"10.1016/j.matcom.2024.09.009","DOIUrl":"10.1016/j.matcom.2024.09.009","url":null,"abstract":"<div><div>In this paper, we numerically investigate vector solitons with oscillatory phase backgrounds in the integrable coupled nonlinear Schrödinger equations, which are widely applied to varieties of physical contexts such as the simultaneous propagation of nonlinear optical pulses and the dynamics of two-components Bose–Einstein condensates. We develop the time-splitting Chebyshev–Galerkin method based on a transformation to accurately compute the vector soliton solutions. Compared to the finite difference method, numerical experiments show that the method with spectral accuracy and high efficiency is necessary for simulating the dynamics evolution of vector solitons. Combined with modulation instability conditions, linear stability analysis and direct numerical simulation, we reveal that the bright-dark and dark-dark solitons with various combinations of parameters under perturbations have qualitative differences. Particularly, vector solitons in unstable background with different wave numbers present distinct dynamics evolutions. The results help us to understand soliton dynamics with oscillatory phase backgrounds and the superposition between nonlinear waves.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328103","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

Control of a 15MW off-shore wind turbine for black-start operation 控制 15 兆瓦离岸风力涡轮机进行黑启动运行

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-19 DOI: 10.1016/j.matcom.2024.09.013

Gala Navarro-Martínez, Jaime Martínez-Turégano, Ramon Blasco-Gimenez

{"title":"Control of a 15MW off-shore wind turbine for black-start operation","authors":"Gala Navarro-Martínez, Jaime Martínez-Turégano, Ramon Blasco-Gimenez","doi":"10.1016/j.matcom.2024.09.013","DOIUrl":"10.1016/j.matcom.2024.09.013","url":null,"abstract":"<div><div>Grid forming wind turbines are crucial for achieving a 100% renewable based grid. The mechanical control of the wind turbines is usually designed for maximum power tracking operation. This paper includes the development of a wind turbine pitch controller considering the wider operational range of a grid forming wind turbine. The proposed controller tracks the optimal generation characteristic of the wind turbine when grid connected and is designed to cater for the different power levels when the wind turbine is operated in islanded mode (or grid-connected at partial power). The proposed controller does not require wind speed estimation for its operation and shows better performance than standard pitch controllers during grid-forming operation, particularly, limiting wind turbine speed excursion during block de-loading. Moreover, the proposed controller does not increase the mechanical loads of the key wind turbine elements. The performance of the proposed control is validated in a black start procedure with a full wind farm realistic real-time simulator, including detailed electrical and aeroelastic models of the wind turbine generator, wind farm and connecting HVDC link. Time and frequency domain validation using the real-time model has shown the performance of the proposed controller during black start operation.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Kinetic description and macroscopic limit of swarming dynamics with continuous leader–follower transitions 具有连续领导者-追随者转换的蜂群动力学动力学描述和宏观极限

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-19 DOI: 10.1016/j.matcom.2024.09.006

Emiliano Cristiani , Nadia Loy , Marta Menci , Andrea Tosin

引用次数: 0

A study of stochastically perturbed epidemic model of HPV infection and cervical cancer in Indian female population 印度女性 HPV 感染与宫颈癌随机扰动流行模型研究

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-19 DOI: 10.1016/j.matcom.2024.09.008

T.A. Midhun, K. Murugesan

{"title":"A study of stochastically perturbed epidemic model of HPV infection and cervical cancer in Indian female population","authors":"T.A. Midhun, K. Murugesan","doi":"10.1016/j.matcom.2024.09.008","DOIUrl":"10.1016/j.matcom.2024.09.008","url":null,"abstract":"<div><div>This study introduces a novel stochastic SICR (susceptible, infected, cervical cancer and recovered) model to illustrate HPV (Human papillomavirus) infection dynamics and its impact on cervical cancer in the female population of India. We prove the existence of a unique positive global solution that ensures stochastic boundedness and permanence. Moreover, sufficient conditions for HPV extinction are established through the stochastic extinction parameter <span><math><msubsup><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow><mrow><mi>e</mi></mrow></msubsup></math></span>, indicating that the infection will die out if <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow><mrow><mi>e</mi></mrow></msubsup><mo><</mo><mn>1</mn></mrow></math></span>. Conversely, the persistence of HPV is established by the existence and uniqueness of an ergodic stationary distribution of the solution when the stochastic threshold <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow><mrow><mi>s</mi></mrow></msubsup><mo>></mo><mn>1</mn></mrow></math></span>, using the suitable selection of Lyapunov functions. Furthermore, data on cervical cancer cases in India from 2016 to 2020 is fitted to the model, providing parameter values suitable for the region. The theoretical findings are validated using the Positive-Preserving Truncated Euler–Maruyama method. Additionally, effective control strategies for India are suggested based on model predictions and sensitivity of key parameters.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328102","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

A space-time generalized finite difference scheme for long wave propagation based on high-order Korteweg-de Vries type equations 基于高阶 Korteweg-de Vries 型方程的长波传播时空广义有限差分方案

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-19 DOI: 10.1016/j.matcom.2024.09.012

Fan Zhang , Po-Wei Li , Yan Gu , Chia-Ming Fan

{"title":"A space-time generalized finite difference scheme for long wave propagation based on high-order Korteweg-de Vries type equations","authors":"Fan Zhang , Po-Wei Li , Yan Gu , Chia-Ming Fan","doi":"10.1016/j.matcom.2024.09.012","DOIUrl":"10.1016/j.matcom.2024.09.012","url":null,"abstract":"<div><div>In this paper, the space-time generalized finite difference scheme is applied to solve the nonlinear high-order Korteweg-de Vries equations in multiple dimensions. The proposed numerical scheme combines the space-time generalized finite difference method, the Levenberg-Marquardt algorithm, and a time-marching approach. The space-time generalized finite difference method treats the temporal axis as a spatial axis, enabling the proposed scheme to discretize all derivatives in the governing equation. This is accomplished through Taylor series expansion and the moving least squares method. Due to the expandability of the Taylor series to any order, the proposed numerical scheme excels in efficiently handling mixed and higher-order derivatives. These capabilities are distinct advantages of the proposed scheme. The resulting system of algebraic equations is sparse but overdetermined. Therefore, the Levenberg-Marquardt algorithm is directly applied to solve this nonlinear algebraic system. During the calculation process, the time-marching approach reduces computational effort and improves efficiency by dividing the space-time domain.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312014","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

Finding the minimum k-weighted dominating sets using heuristic algorithms 利用启发式算法寻找最小 k 加权支配集

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-18 DOI: 10.1016/j.matcom.2024.09.010

E. Barrena , S. Bermudo , A.G. Hernández-Díaz , A.D. López-Sánchez , J.A. Zamudio

{"title":"Finding the minimum k-weighted dominating sets using heuristic algorithms","authors":"E. Barrena , S. Bermudo , A.G. Hernández-Díaz , A.D. López-Sánchez , J.A. Zamudio","doi":"10.1016/j.matcom.2024.09.010","DOIUrl":"10.1016/j.matcom.2024.09.010","url":null,"abstract":"<div><div>In this work, we propose, analyze, and solve a generalization of the <span><math><mi>k</mi></math></span>-dominating set problem in a graph, when we consider a weighted graph. Given a graph with weights in its edges, a set of vertices is a <span><math><mi>k</mi></math></span>-weighted dominating set if for every vertex outside the set, the sum of the weights from it to its adjacent vertices in the set is bigger than or equal to <span><math><mi>k</mi></math></span>. The <span><math><mi>k</mi></math></span>-weighted domination number is the minimum cardinality among all <span><math><mi>k</mi></math></span>-weighted dominating sets. Since the problem of finding the <span><math><mi>k</mi></math></span>-weighted domination number is <span><math><mi>NP</mi></math></span>-hard, we have proposed several problem-adapted construction and reconstruction techniques and embedded them in an Iterated Greedy algorithm. The resulting sixteen variants of the Iterated Greedy algorithm have been compared with an exact algorithm. Computational results show that the proposal is able to find optimal or near-optimal solutions within a short computational time. To the best of our knowledge, the <span><math><mi>k</mi></math></span>-weighted dominating set problem has never been studied before in the literature and, therefore, there is no other state-of-the-art algorithm to solve it. We have also included a comparison with a particular case of our problem, the minimum dominating set problem and, on average, we achieve same quality results within around 50% of computation time.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

IMACS Calendar of Events IMACS 活动日历

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-17 DOI: 10.1016/S0378-4754(24)00358-6

引用次数: 0

News of IMACS IMACS 新闻

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-17 DOI: 10.1016/S0378-4754(24)00357-4

引用次数: 0

Bistability in a predator–prey model characterized by the Crowley–Martin functional response: Effects of fear, hunting cooperation, additional foods and nonlinear harvesting 以克劳利-马丁功能反应为特征的捕食者-猎物模型的双稳态性：恐惧、狩猎合作、额外食物和非线性收获的影响

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-12 DOI: 10.1016/j.matcom.2024.09.001

Subarna Roy, Pankaj Kumar Tiwari

{"title":"Bistability in a predator–prey model characterized by the Crowley–Martin functional response: Effects of fear, hunting cooperation, additional foods and nonlinear harvesting","authors":"Subarna Roy, Pankaj Kumar Tiwari","doi":"10.1016/j.matcom.2024.09.001","DOIUrl":"10.1016/j.matcom.2024.09.001","url":null,"abstract":"<div><p>This study focuses on unraveling key factors influencing predator–prey interactions with Crowley–Martin functional response. Specifically, it explores the roles of additional food sources, harvesting practices, hunting cooperation, fear and its carry-over effects. We analyze equilibrium points and their stability properties through rigorous mathematical methods. Numerical illustrations showcase a diverse range of bifurcations including Hopf, saddle–node, and transcritical, providing a comprehensive understanding of the system’s dynamics. We find that the collaboration among predators during hunting induces instability in the system, leading to the emergence of population cycles from a stable state. Further, we place emphasis on investigating the impact of seasonal forcing by introducing time-varying parameters into our model. We reveal the emergence of periodic solutions, higher periodic solutions and chaotic dynamics due to the seasonal variations of the prey’s birth rate and the degree of hunting cooperation. We also emphasize the significance of incorporating different periodicity of seasonally forced parameters, leading to a more precise understanding of predator–prey dynamics.</p></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242599","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

Solving the Laplace equation on the disc using the UAT spline 使用 UAT 花键求解圆盘上的拉普拉斯方程

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-09-12 DOI: 10.1016/j.matcom.2024.09.004

M. Naimi, M. Lamnii

{"title":"Solving the Laplace equation on the disc using the UAT spline","authors":"M. Naimi, M. Lamnii","doi":"10.1016/j.matcom.2024.09.004","DOIUrl":"10.1016/j.matcom.2024.09.004","url":null,"abstract":"<div><div>In this work, we are interested in the resolution of the Laplace equation <span><math><mrow><mo>−</mo><mi>Δ</mi><mi>u</mi><mo>=</mo><mi>f</mi></mrow></math></span> with Dirichlet boundary condition in a closed surface <span><math><mi>S</mi></math></span> in <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>, which is – topologically – equivalent to the unit disc <span><math><mrow><mi>D</mi><mo>=</mo><mrow><mo>{</mo><mfenced><mrow><mi>x</mi><mo>,</mo><mi>y</mi></mrow></mfenced><mo>|</mo><mspace></mspace><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msup><mrow><mi>y</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>⩽</mo><mn>1</mn><mo>}</mo></mrow></mrow></math></span>. It is known that for a function <span><math><mi>u</mi></math></span> represented in polar coordinates on <span><math><mi>D</mi></math></span>, certain boundary conditions must be satisfied by <span><math><mi>u</mi></math></span> so that the surface <span><math><mi>S</mi></math></span> is of class <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>0</mn></mrow></msup></math></span>. More precisely, we construct an approximant of class <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>0</mn></mrow></msup></math></span> on <span><math><mi>D</mi></math></span> as a tensor product of two quasi-interpolants, one based on UAT-splines and the other based on classical B-splines. Some numerical results are given to validate the work.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357111","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