Mathematics and Computers in Simulation最新文献_第2页

Algorithmic modelling of a complex redundant multi-state system subject to multiple events, preventive maintenance, loss of units and a multiple vacation policy through a MMAP 通过 MMAP 建立受多重事件、预防性维护、单元损失和多重休假政策影响的复杂冗余多状态系统的算法模型

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-16 DOI: 10.1016/j.matcom.2024.11.005

Juan Eloy Ruiz-Castro , Hugo Alaín Zapata-Ceballos

{"title":"Algorithmic modelling of a complex redundant multi-state system subject to multiple events, preventive maintenance, loss of units and a multiple vacation policy through a MMAP","authors":"Juan Eloy Ruiz-Castro , Hugo Alaín Zapata-Ceballos","doi":"10.1016/j.matcom.2024.11.005","DOIUrl":"10.1016/j.matcom.2024.11.005","url":null,"abstract":"<div><div>A complex multi-state redundant system undergoing preventive maintenance and experiencing multiple events is being considered in a continuous time frame. The online unit is susceptible to various types of failures, both internal and external in nature, with multiple degradation levels present, both internally and externally. Random inspections are continuously monitoring these degradation levels, and if they reach a critical state, the unit is directed to a repair facility for preventive maintenance. The maintenance place is managed by a repairperson, who follows a multiple vacation policy dependent on the operational status of the units. The repairperson is responsible for two primary tasks: corrective repair and preventive maintenance. The time durations within the system follow phase-type distributions, and the model is constructed utilizing Markovian Arrival Processes with marked arrivals. A variety of performance measures, including transient and stationary distributions, are calculated using matrix-analytic methods. This methodology allows for the representation of significant outcomes and the general behavior of the system in a matrix-algorithmic structure. To enhance the model's efficiency, both costs and rewards are incorporated into the analysis. A numerical example is presented to showcase the model's flexibility and effectiveness in real-world applications.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"230 ","pages":"Pages 165-192"},"PeriodicalIF":4.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700824","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

On numerical resolution of shape optimization bi-Laplacian eigenvalue problems 关于形状优化双拉普拉卡特征值问题的数值求解

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-16 DOI: 10.1016/j.matcom.2024.11.007

Abdelkrim Chakib , Ibrahim Khalil , Azeddine Sadik

引用次数: 0

Finite-time synchronization analysis for the generalized Caputo fractional spatio-temporal neural networks 广义卡普托分数时空神经网络的有限时间同步分析

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-13 DOI: 10.1016/j.matcom.2024.11.006

Xianghu Liu, Yanfang Li, Guangjun Xu

引用次数: 0

A perception-guided CNN for grape bunch detection 用于葡萄串检测的感知引导型 CNN

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-12 DOI: 10.1016/j.matcom.2024.11.004

Vittoria Bruni , Giulia Dominijanni , Domenico Vitulano , Giuliana Ramella

{"title":"A perception-guided CNN for grape bunch detection","authors":"Vittoria Bruni , Giulia Dominijanni , Domenico Vitulano , Giuliana Ramella","doi":"10.1016/j.matcom.2024.11.004","DOIUrl":"10.1016/j.matcom.2024.11.004","url":null,"abstract":"<div><div>Precision Viticulture (PV) is becoming an active and interdisciplinary research field since it requires solving interesting research issues to concretely answer the demands of specific use cases. A challenging problem in this context is the development of automatic methods for yield estimation. Computer vision methods can contribute to the accomplishment of this task, especially those that can replicate what winemakers do manually. In this paper, an automatic artificial intelligence method for grape bunch detection from RGB images is presented. A customized Convolutional Neural Network (CNN) is employed for pointwise classification of image pixels and the dependence of classification results on the type of input color channels and grapes color properties are studied. The advantage of using additional perception-based input features, such as luminance and visual contrast, is also evaluated, as well as the dependence of the method on the choice of the training set in terms of the amount of labeled data. The latter point has a significant impact on the practical use of the method on-site, its usability by non-expert users, and its adaptability to individual vineyards. Experimental results show that a properly trained CNN can discriminate and detect grape bunches even under uncontrolled acquisition conditions and with limited computational load, making the proposed method implementable on smart devices and suitable for on-site and real-time applications.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"230 ","pages":"Pages 111-130"},"PeriodicalIF":4.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700823","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

An innovative fractional grey system model and its application 创新的分数灰色系统模型及其应用

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-10 DOI: 10.1016/j.matcom.2024.11.003

Wen-Ze Wu , Jie Xu , Wanli Xie , Tao Zhang

引用次数: 0

Large time solution for collisional breakage model: Laplace transformation based accelerated homotopy perturbation method 碰撞破裂模型的大时间求解：基于拉普拉斯变换的加速同调扰动法

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-09 DOI: 10.1016/j.matcom.2024.11.001

Shweta , Gourav Arora , Rajesh Kumar

{"title":"Large time solution for collisional breakage model: Laplace transformation based accelerated homotopy perturbation method","authors":"Shweta , Gourav Arora , Rajesh Kumar","doi":"10.1016/j.matcom.2024.11.001","DOIUrl":"10.1016/j.matcom.2024.11.001","url":null,"abstract":"<div><div>The behavior of several particulate processes, such as cell interaction, blood clotting, bubble formation, grain breakage, and cheese formation from milk, have been studied using coagulation and fragmentation models (Fogelson and Guy, 2008 <span><span>[1]</span></span>; Pazmiño et al., 2022 <span><span>[2]</span></span>; Chen et al., <span><span>[3]</span></span>). Various studies utilize the linear fragmentation model to simplify the underlying physics. However, in real-life scenarios, particles form due to the collision of two particles, leading to a non-linear collisional breakage model. Unfortunately, the collisional breakage model is less explored due to its complex behavior. While analytical solutions are difficult to compute and are still missing in the literature, this article proposes an approximate solution for the model using the Laplace-based accelerated homotopy perturbation method. Further, coupling with Padé approximant, the accuracy of the solution is extended for the longer time. Considering various physically relevant kernels, the approximate series solutions are compared with the well known finite-volume solutions to measure the accuracy in terms of qualitative and quantitative errors. The article also encompasses theoretical convergence analysis and error estimations to enhance comprehension of the proposed formulation.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"230 ","pages":"Pages 39-52"},"PeriodicalIF":4.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659322","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

Efficient second-order accurate exponential time differencing for time-fractional advection–diffusion–reaction equations with variable coefficients 具有可变系数的时间分数平流-扩散-反应方程的高效二阶精确指数时差法

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-09 DOI: 10.1016/j.matcom.2024.11.002

Ibrahim O. Sarumi , Khaled M. Furati , Abdul Q.M. Khaliq

{"title":"Efficient second-order accurate exponential time differencing for time-fractional advection–diffusion–reaction equations with variable coefficients","authors":"Ibrahim O. Sarumi , Khaled M. Furati , Abdul Q.M. Khaliq","doi":"10.1016/j.matcom.2024.11.002","DOIUrl":"10.1016/j.matcom.2024.11.002","url":null,"abstract":"<div><div>Time-fractional advection–diffusion–reaction type equations are useful for characterizing anomalous transport processes. In this paper, linearly implicit as well as explicit generalized exponential time differencing (GETD) schemes are proposed for solving a class of such equations having time–space dependent coefficients. The implicit scheme, being unconditionally stable, is robust in handling the numerical instabilities in problems where the advection term is dominant. Regarding the error analysis, uniformly optimal second-order convergence rates are derived using time-graded meshes to counter the effect of the inherent singularity of the continuous solution. Implementation of generalized exponential integrators requires computing the action of Mittag-Leffler function of matrices on a vector, or on a matrix in the case of the implicit scheme. For cost-effective implementation, using global Padé approximants these computation tasks get reduced to solving linear systems. A new approach based on Sylvester equation formulation of the resulting linear systems is developed in this paper. This technique leads to significantly faster algorithms for implementing the GETD schemes. Numerical experiments are provided to illustrate the theoretical findings and to assert the efficiency of the Sylvester equation based approach. Application of this approach to an existing GETD scheme for solving a nonlinear subdiffusion problem is also discussed.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"230 ","pages":"Pages 20-38"},"PeriodicalIF":4.4,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659492","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

Multi-objective optimization of the appendages of a sailing yacht using the Normal Boundary Intersection method 使用法线边界交叉法对帆船的附属装置进行多目标优化

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-07 DOI: 10.1016/j.matcom.2024.10.041

Daniele Peri

引用次数: 0

Unified algorithms for distributed regularized linear regression model 分布式正则化线性回归模型的统一算法

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-07 DOI: 10.1016/j.matcom.2024.10.018

Bingzhen Chen , Wenjuan Zhai

{"title":"Unified algorithms for distributed regularized linear regression model","authors":"Bingzhen Chen , Wenjuan Zhai","doi":"10.1016/j.matcom.2024.10.018","DOIUrl":"10.1016/j.matcom.2024.10.018","url":null,"abstract":"<div><div>In recent years, distributed statistical models have received increasing attention for large-scale data analysis. On the one hand, data sets come from multiple data sources, and are stored in different locations due to limited bandwidth and storage, or privacy protocols, directly centralizing all data together is impossible. On the other hand, the size of data is so large that it is difficult or inefficient to analyze data together. There are two main research aspects to using distributed statistical models to analyze large-scale data. The first one is to study the statistical convergence rate under some mild assumptions. The second one is to establish fast and efficient optimization algorithms considering the property of the loss function. There is a lot of research on the first aspect, but relatively little research on the second one. Motivated by this, we consider the construction of unified algorithms for distributed linear regression with different losses and regularizers. As a result, we designed two type methods, proximal alternating direction method of multipliers (pADMM) and distributed accelerated proximal gradient method with line-search (DAPGL). In order to demonstrate the efficiency of the proposed algorithms, we perform numerical experiments on the distributed Huber-Lasso model and Huber-Group-Lasso model. In view of the numerical results, we can observe that these two algorithms are more competitive than some of state-of-art algorithms. In particular, DAPGL algorithm performs better than pADMM in most cases.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"229 ","pages":"Pages 867-884"},"PeriodicalIF":4.4,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659627","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

Dynamic analysis and data-driven inference of a fractional-order SEIHDR epidemic model with variable parameters 参数可变的分数阶 SEIHDR 流行病模型的动态分析和数据驱动推断

IF 4.4 2区数学

Mathematics and Computers in Simulation Pub Date : 2024-11-07 DOI: 10.1016/j.matcom.2024.10.042

Ruqi Li , Yurong Song , Min Li , Hongbo Qu , Guo-Ping Jiang

{"title":"Dynamic analysis and data-driven inference of a fractional-order SEIHDR epidemic model with variable parameters","authors":"Ruqi Li , Yurong Song , Min Li , Hongbo Qu , Guo-Ping Jiang","doi":"10.1016/j.matcom.2024.10.042","DOIUrl":"10.1016/j.matcom.2024.10.042","url":null,"abstract":"<div><div>To analyze and predict the evolution of contagion dynamics, fractional derivative modeling has emerged as an important technique. However, inferring the dynamical structure of fractional-order models with high degrees of freedom poses a challenge. In this paper, to elucidate the spreading mechanism and non-local properties of disease evolution, we propose a novel fractional-order SEIHDR epidemiological model with variable parameters, incorporating fractional derivatives in the Caputo sense. We compute the basic reproduction number by the next-generation matrix and establish local and global stability conditions based on this reproduction number. By using the fractional Adams–Bashforth method, we validate dynamical behaviors at different equilibrium points in both autonomous and non-autonomous scenarios, while qualitatively analyze the effects of fractional order on the dynamics. To effectively address the inverse problem of the proposed fractional SEIHDR model, we construct a fractional Physics-Informed Neural Network framework to simultaneously infer time-dependent parameters, fractional orders, and state components. Graphical results based on the COVID-19 pandemic data from Canada demonstrate the effectiveness of the proposed framework.</div></div>","PeriodicalId":49856,"journal":{"name":"Mathematics and Computers in Simulation","volume":"230 ","pages":"Pages 1-19"},"PeriodicalIF":4.4,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659321","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