Mathematics and Computers in Simulation最新文献_第3页

An age-structured mathematical model for studying Malaria transmission dynamics: Applications to some areas of Senegal 研究疟疾传播动态的年龄结构数学模型：塞内加尔部分地区的应用

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-15 DOI: 10.1016/j.matcom.2024.10.006

Rama Seck , Diene Ngom , Benjamin Ivorra , Angel M. Ramos

{"title":"An age-structured mathematical model for studying Malaria transmission dynamics: Applications to some areas of Senegal","authors":"Rama Seck , Diene Ngom , Benjamin Ivorra , Angel M. Ramos","doi":"10.1016/j.matcom.2024.10.006","DOIUrl":"10.1016/j.matcom.2024.10.006","url":null,"abstract":"<div><div>In this work, we formulate an age-structured model for studying the transmission of Malaria for both human and vector populations. First, we perform an analytical study of this model. To do so, we analyze the positivity and boundedness of solutions and study the stability of the Disease-Free Equilibrium (using a matrix-tree theorem). Then, we focus on the study of the Endemic Equilibrium. Applying a methodology grounded in graph theory, we prove that, under certain assumptions, the Endemic Equilibrium is both unique and globally asymptotically stable. We also conjecture that this result holds true even in cases where these assumptions are not met. While this conjecture remains unproven, it is supported by illustrative numerical experiments. Secondly, we illustrate the interest of our approach by considering real data from two specific areas in Senegal affected by Malaria, namely Dielmo and Ndiop. In particular, we estimate some of the model parameters for these zones and illustrate how the proposed model may help to estimate the behavior of Malaria outbreaks.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530243","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

Analytical expressions of the dynamic magnetic power loss under alternating or rotating magnetic field 交变或旋转磁场下动态磁功率损耗的分析表达式

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-12 DOI: 10.1016/j.matcom.2024.10.009

B. Ducharne , G. Sebald

{"title":"Analytical expressions of the dynamic magnetic power loss under alternating or rotating magnetic field","authors":"B. Ducharne , G. Sebald","doi":"10.1016/j.matcom.2024.10.009","DOIUrl":"10.1016/j.matcom.2024.10.009","url":null,"abstract":"<div><div>Analytical methods are recommended for rapid predictions of the magnetic core loss as they require less computational resources and offer straightforward sensitivity analysis. This paper proposes analytical expressions of the dynamic magnetic power loss under an alternating or rotating magnetic field. The formulations rely on fractional derivative analytical expressions of trigonometric functions. The simulation method is validated on extensive experimental data obtained from state-of-the-art setups and gathered in the scientific literature. Five materials are tested for up to at least 1 kHz in both alternating and rotating conditions. The relative Euclidean distance between the simulated and experimentally measured power loss is lower than 5 % for most tested materials and always lower than 10 %. In standard characterization conditions, i.e., sinusoidal flux density, the dynamic power loss contribution under a rotating magnetic field is shown to be precisely two times higher than an alternating one. The knowledge of electrical conductivity reduces the dynamic magnetic power loss contribution to a single parameter (the fractional order). This parameter has the same value for a given material's rotational and alternating contribution. This study confirms the viscoelastic behavior of the magnetization process in ferromagnetic materials and, consequently, the relevance of the fractional derivative operators for their simulation.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446957","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 new proximal gradient method for solving mixed variational inequality problems with a novel explicit stepsize and applications 解决混合变分不等式问题的新近似梯度法及其应用

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-11 DOI: 10.1016/j.matcom.2024.10.008

Pham Thi Hoai

引用次数: 0

GPGPU-based heterogeneous parallel implementation of direct discontinuous Galerkin methods 基于 GPGPU 的直接非连续伽勒金方法的异构并行实施

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-11 DOI: 10.1016/j.matcom.2024.09.034

Jiaxin Wang , Kun Wang , Zhen-Guo Yan , Xiaofeng He , Tiegang Liu

{"title":"GPGPU-based heterogeneous parallel implementation of direct discontinuous Galerkin methods","authors":"Jiaxin Wang , Kun Wang , Zhen-Guo Yan , Xiaofeng He , Tiegang Liu","doi":"10.1016/j.matcom.2024.09.034","DOIUrl":"10.1016/j.matcom.2024.09.034","url":null,"abstract":"<div><div>This paper implements the CUDA and hybrid CUDA/MPI parallel computation based on GPGPU heterogeneous parallel strategies for the direct discontinuous method (DDG) on 3D unstructured grids. The direct discontinuous Galerkin method inherits the compactness of the discontinuous Galerkin (DG) method, making it well-suited for large-scale parallelization. Firstly, we present the full single-GPU implementation of the three-dimensional (3D) DDG method with cell-level parallelism and face-level parallelism. Herein, all the numerical operators including volume integration, face integration (numerical fluxes), conservation variables calculation, and time iteration, are implemented by designing the corresponding kernel functions. Especially, we implement several key memory access optimization strategies, which are crucial for performance improvement. Operators merging and shared memory utilizing reduces the number of global access. Such memory Coalescing and data structure reconstruction apparently enhances the efficiency of global memory access. To align with data access pattern, we employ atomic operations to eliminate data race conditions. Furthermore, we propose a full hybrid GPU/CPU heterogeneous parallel strategy to implement multi-GPU parallelization of the DDG method, where asynchronization optimization is introduced to fully overlap communication and computation and basically eliminates the communication overhead. Finally, several numerical tests are conducted on Tesla V100 Cards to show performance of the parallelization. In addition, we utilize the NVIDIA performance testing tool, <span><math><mrow><mi>n</mi><mi>v</mi><mi>p</mi><mi>r</mi><mi>o</mi><mi>f</mi></mrow></math></span>, to evaluate multiple metrics of the kernel functions and conduct a detailed analysis of the results. In the tests of parallel scalability, the weak scaling efficiency achieves 97% from 4 to 32 GPU cards, and the strong scaling efficiency is 90% from 1 to 8 GPU cards.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530242","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

Comparison of global sensitivity analysis methods for a fire spread model with a segmented characteristic 具有分段特征的火灾蔓延模型的全局敏感性分析方法比较

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-11 DOI: 10.1016/j.matcom.2024.10.012

Shi-Shun Chen, Xiao-Yang Li

引用次数: 0

Short-term electricity price forecasting through demand and renewable generation prediction 通过需求和可再生能源发电预测进行短期电价预测

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-10 DOI: 10.1016/j.matcom.2024.10.004

E. Belenguer, J. Segarra-Tamarit, E. Pérez, R. Vidal-Albalate

引用次数: 0

Three-dimensional numerical wave tank containing submerged breakwaters based on the localized method of fundamental solutions 基于局部基本解法的包含水下防波堤的三维数值波浪槽

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-10 DOI: 10.1016/j.matcom.2024.10.005

Lanlan Li , Zhuojia Fu , Ming Qin , Shuainan Liu , Weihong Zeng , Xiaoting Liu

{"title":"Three-dimensional numerical wave tank containing submerged breakwaters based on the localized method of fundamental solutions","authors":"Lanlan Li , Zhuojia Fu , Ming Qin , Shuainan Liu , Weihong Zeng , Xiaoting Liu","doi":"10.1016/j.matcom.2024.10.005","DOIUrl":"10.1016/j.matcom.2024.10.005","url":null,"abstract":"<div><div>This paper presents a meshless computational framework to simulate nonlinear water wave propagation behaviors of three-dimensional (3D) numerical wave tank containing submerged trapezoidal breakwaters. In the present computational framework, the localized method of fundamental solutions (LMFS) is used to spatial discretization, which is a localized meshless collocation method based on fundamental solutions and moving least square (MLS) technique, and fourth-order predictor-corrector scheme is used to temporal discretization. 3D numerical wave tanks containing single submerged trapezoidal breakwater and double submerged trapezoidal breakwaters are established by using LMFS. The LMFS results are compared with analytical results and experimental data through benchmarks. The effects of variations in incident wave parameters and shape parameters of the submerged trapezoidal breakwater on wave propagation are further analyzed. Additionally, the influence of double submerged trapezoidal breakwaters on the nonlinear water wave propagation behavior is investigated in comparison with the single submerged trapezoidal breakwater. Moreover, the effect of breakwater orientation on wave propagation is presented.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418191","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 dynamic analysis of a tourism-based socioecological system 以旅游业为基础的社会生态系统动态分析

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-09 DOI: 10.1016/j.matcom.2024.08.001

Andreea-Maria Ardeuan , Mihaela Neamţu , Adriana Loredana Tănasie

{"title":"A dynamic analysis of a tourism-based socioecological system","authors":"Andreea-Maria Ardeuan , Mihaela Neamţu , Adriana Loredana Tănasie","doi":"10.1016/j.matcom.2024.08.001","DOIUrl":"10.1016/j.matcom.2024.08.001","url":null,"abstract":"<div><div>The study proposes a dynamic analysis regarding interactions between the resources provided by the forest, the wildlife present inside or in the proximity of that environment and visitors revolving around the before mentioned socioecological framework. The mathematical model is described by a nonlinear system with three differential equations. The discrete time delay is introduced to illustrate the entire past impact of tourists on forest resources and wildlife. The basic assumption is that the wildlife species which inhabit the area are relying entirely on forest resources to meet their needs for food, shelter, and to attract tourists. Also, there is a positive correlation between ecotourism activities and the presence of forest resources and wildlife. The equilibrium states are determined, and they are subjected to a stability and bifurcation analysis. The study employs a Hopf bifurcation analysis in the neighborhood of the equilibrium states by choosing the time delay as the bifurcation parameter. The critical values of the time-delay that lead to oscillatory behavior are determined. Numerical simulations are carried out to show the system’s qualitative behavior in the vicinity of the equilibria.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418203","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

Type-2 fuzzy initial value problems under granular differentiability 颗粒可微分性下的第二类模糊初值问题

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-05 DOI: 10.1016/j.matcom.2024.10.002

Dhabaleswar Mohapatra , S. Chakraverty

引用次数: 0

Adaptive optimal coordination control of perturbed Bilateral Teleoperators with variable time delays using Actor–Critic Reinforcement Learning algorithm 使用演员批判强化学习算法，对具有可变时间延迟的扰动双边远程操作员进行自适应优化协调控制

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-10-05 DOI: 10.1016/j.matcom.2024.09.007

Phuong Nam Dao, Quang Phat Nguyen, Manh Hung Vu

{"title":"Adaptive optimal coordination control of perturbed Bilateral Teleoperators with variable time delays using Actor–Critic Reinforcement Learning algorithm","authors":"Phuong Nam Dao, Quang Phat Nguyen, Manh Hung Vu","doi":"10.1016/j.matcom.2024.09.007","DOIUrl":"10.1016/j.matcom.2024.09.007","url":null,"abstract":"<div><div>In this article, we study the unification of coordination control problem between two sides and optimal control effectiveness for an unknown Bilateral Teleoperators (BTs) under variable time delays in communication between two sides and external disturbance. We proposed the control frame of Actor/Critic strategy and the Robust Integral of the Sign of the Error (RISE), in which the synchronization effectiveness is discussed in two sections with different conditions. The sliding variable is given to transform a BT dynamic model into order reduction model, which can be designed more favourable. By fully analysing optimization problem in designing the training weights of Actor/Critic structure based on the property of Hamiltonian term, Reinforcement Learning (RL) control scheme in each side is proposed for a BT system. Consequently, we incorporate the RISE term into proposed control frame to mathematically prove that the tracking errors asymptotically converge to zero. Furthermore, the proposed control strategy can also guarantee the convergence of learning process. Simulation results and the comparisons demonstrate the performance of the proposed control framework.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418186","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