Journal of Computational Science最新文献_第5页

Negative results on density determination with one-dimensional cellular automata with block-sequential asynchronous updates 用分块序列异步更新的一维蜂窝自动机确定密度的负面结果

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-09-02 DOI: 10.1016/j.jocs.2024.102430

Eurico Ruivo , Kévin Perrot , Pedro Paulo Balbi , Pacôme Perrotin

{"title":"Negative results on density determination with one-dimensional cellular automata with block-sequential asynchronous updates","authors":"Eurico Ruivo , Kévin Perrot , Pedro Paulo Balbi , Pacôme Perrotin","doi":"10.1016/j.jocs.2024.102430","DOIUrl":"10.1016/j.jocs.2024.102430","url":null,"abstract":"<div><p>A large number of research efforts have been made in trying to solve global decision problems with cellular automata by means of their cells reaching a distributed consensus via their local action. Among them, the determination of the most frequent state in configurations with arbitrary size, i.e., the density classification task, has been the most widely approached benchmark problem. The literature abounds with cases demonstrating that, depending on how it is formulated, a solution can be shown to exist or not. Here we address the problem in terms of deterministic, block-sequential asynchronous updates, over cyclic configurations, by which the possibility of a solution remains open. Our main results are negative in terms of the possibility of solving the problem with such formulation, encompassing the cases of any cellular automaton with any sequential update, and any elementary cellular automaton with any block-sequential update; furthermore, we uncover some properties that any potential solution with block-sequential update should have in order for it to be a candidate to solving the problem. Incidentally, we also give a new, very simple proof of the impossibility of solving the problem with any synchronous rule.</p></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"82 ","pages":"Article 102430"},"PeriodicalIF":3.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142136621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advanced sampling discovers apparently similar ankle models with distinct internal load states under minimal parameter modification 高级采样发现了表面上相似的脚踝模型，在参数修改最小的情况下，其内部负载状态却截然不同

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-30 DOI: 10.1016/j.jocs.2024.102425

Miroslav Vořechovský , Adam Ciszkiewicz

{"title":"Advanced sampling discovers apparently similar ankle models with distinct internal load states under minimal parameter modification","authors":"Miroslav Vořechovský , Adam Ciszkiewicz","doi":"10.1016/j.jocs.2024.102425","DOIUrl":"10.1016/j.jocs.2024.102425","url":null,"abstract":"<div><p>Creating valid and trustworthy models is a key issue in biomedical engineering that affects the quality of life of both patients and healthy individuals in various scientific and industrial domains. This however is a difficult task due to the complex nature of biomechanical joints. In this study, a sampling strategy combining Genetic Algorithm and clustering is proposed to investigate biomechanical joints. A computational model of a human ankle joint with 43 input parameters serves as an illustrative case for the procedure. The Genetic Algorithm is used to efficiently search for distinct variants of the model with similar output, while clustering helps to quantify the obtained results. The search is performed in a close vicinity to the original model, mimicking subjective decisions in parameter acquisition. The method reveals twelve distinct clusters in the model parameter set, all resulting in the same angular displacements. These clusters correspond to three unique internal load states for the model, confirming the complex nature of the ankle. The proposed approach is general and could be applied to study other models in mechanical engineering and robotics.</p></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"82 ","pages":"Article 102425"},"PeriodicalIF":3.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Finite Element Method on locally refined composite meshes for Dirichlet fractional Laplacian 针对 Dirichlet 分数拉普拉斯的局部细化复合网格有限元法

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-30 DOI: 10.1016/j.jocs.2024.102433

Jun Zhou, Hongbin Chen

引用次数: 0

Highly efficient NURBS-based isogeometric analysis for coupled nonlinear diffusion–reaction equations with and without advection 基于 NURBS 的高效等距分析，适用于有平流和无平流的耦合非线性扩散-反应方程

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-30 DOI: 10.1016/j.jocs.2024.102434

Ilham Asmouh, Alexander Ostermann

{"title":"Highly efficient NURBS-based isogeometric analysis for coupled nonlinear diffusion–reaction equations with and without advection","authors":"Ilham Asmouh, Alexander Ostermann","doi":"10.1016/j.jocs.2024.102434","DOIUrl":"10.1016/j.jocs.2024.102434","url":null,"abstract":"<div><p>Nonlinear diffusion–reaction systems model a multitude of physical phenomena. A common situation is biological development modeling where such systems have been widely used to study spatiotemporal phenomena in cell biology. Systems of coupled diffusion–reaction equations are usually subject to some complicated features directly related to their multiphysics nature. Moreover, the presence of advection is source of numerical instabilities, in general, and adds another challenge to these systems. In this study, we propose a NURBS-based isogeometric analysis (IgA) combined with a second-order Strang operator splitting to deal with the multiphysics nature of the problem. The advection part is treated in a semi-Lagrangian framework and the resulting diffusion–reaction equations are then solved using an efficient time-stepping algorithm based on operator splitting. The accuracy of the method is studied by means of a advection–diffusion–reaction system with analytical solution. To further examine the performance of the new method on geometries more general than rectangles (e.g., L-shaped domains and parts of annuli), the well-known Schnakenberg–Turing problem is considered with and without advection. Finally, a Gray–Scott system on a circular domain is also presented. The results obtained demonstrate the efficiency of our new algorithm to accurately reproduce the solution in the presence of complex patterns on more complicated geometries. Moreover, the new method clarifies the effect of geometry on Turing patterns.</p></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102434"},"PeriodicalIF":3.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1877750324002278/pdfft?md5=08cba31da5697d13b5d5ac89f8b16f40&pid=1-s2.0-S1877750324002278-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamics of Fourier's and Fick's laws on the convectively heated oscillatory sheet under Arrhenius kinetics: The finite-difference technique 阿伦尼乌斯动力学条件下对流加热振荡片上的傅里叶定律和菲克定律的动力学：有限差分技术

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-30 DOI: 10.1016/j.jocs.2024.102428

Pudhari Srilatha , K. Karthik , Koushik V. Prasad , Amal Abdulrahman , R.S. Varun Kumar , R.J. Punith Gowda , R. Naveen Kumar

{"title":"Dynamics of Fourier's and Fick's laws on the convectively heated oscillatory sheet under Arrhenius kinetics: The finite-difference technique","authors":"Pudhari Srilatha , K. Karthik , Koushik V. Prasad , Amal Abdulrahman , R.S. Varun Kumar , R.J. Punith Gowda , R. Naveen Kumar","doi":"10.1016/j.jocs.2024.102428","DOIUrl":"10.1016/j.jocs.2024.102428","url":null,"abstract":"<div><p>The significance of chemical reaction with activation energy and convective boundary conditions on the fluid flow via an oscillatory stretchy surface in the presence of permeable media and radiation is analyzed in this study. This inspection presents Fourier and Fick's laws-based equations for heat, mass transport, and liquid flow through an oscillating stretchy sheet. Understanding these dynamics aids in the optimisation of catalytic reaction settings, where gradients greatly influence reaction rates in concentration and temperature. The governing differential equations of the current study are modelled and changed into their non-dimensional form by employing suitable similarity variables. The finite difference method (FDM) is also used to numerically solve the obtained dimensionless equations. The influence of many factors on the several profiles is portrayed with graphical representations. The outcome of the unsteadiness and porosity parameters on the velocity profile with time coordinate is depicted. The increase in the radiation parameter and Biot number upsurges the thermal profile. The temperature reduces as the unsteadiness parameter and temperature relaxation time parameter grow. The upsurge in the activation energy parameter intensifies the mass transport. The rise in concentration relaxation time parameter diminishes the concentration profile.</p></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"82 ","pages":"Article 102428"},"PeriodicalIF":3.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142129572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Toward Jordan decompositions for tensors 实现张量的乔丹分解

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-30 DOI: 10.1016/j.jocs.2024.102431

Frédéric Holweck , Luke Oeding

引用次数: 0

Compatible multi-model output fusion for complex systems modeling via set operation-based focus data identification 通过基于集合操作的焦点数据识别，为复杂系统建模实现兼容的多模型输出融合

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-21 DOI: 10.1016/j.jocs.2024.102423

Chenhao Yu , Leilei Chang , Xiaobin Xu , You Cao , Zhenjie Zhang

{"title":"Compatible multi-model output fusion for complex systems modeling via set operation-based focus data identification","authors":"Chenhao Yu , Leilei Chang , Xiaobin Xu , You Cao , Zhenjie Zhang","doi":"10.1016/j.jocs.2024.102423","DOIUrl":"10.1016/j.jocs.2024.102423","url":null,"abstract":"<div><p>Is an inferior model completely useless in complex systems modeling? This study proposes a novel multi-model output fusion approach that makes the best of the outputs from multi-models, i.e., using the limited superior results from inferior models to compensate for certain inferior results from even superior models. For fusing the outputs from multi-models, the weight assigned to each output is calculated based on two factors, namely the accuracy of each model and the similarity between the testing input and the focus data used for constructing the respective model. Specifically for similarity calculation, the focus data list is identified based on set operations. There are three theoretical contributions of this study, namely accuracy-and-similarity-based weight calculation, the set-operation-based similarity calculation which is an addition to traditional distance-based calculation, and the high compatibility of the proposed approach which is independent from any baseline approach. A practical case of overall reconnaissance capability evaluation of the Unmanned Aerial Vehicle (UAV) swarm is studied for validation. Primary results indicate that the proposed approach can outperform two single models: the backpropagation neural network (BPNN) and the Radial Basis Function (RBF) neural network. Further validations demonstrate that the proposed approach also outperforms multi-model output fusion with equal weights, without model accuracy, with varied focus data percentages ranging from 0.1 to 0.9. More importantly, the proposed approach remains effective in four different conditions of multi-model outputs fusion with improvements from 9.58 % to 38.03 %.</p></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"82 ","pages":"Article 102423"},"PeriodicalIF":3.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142049120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quasi-linear time heuristic to solve the Euclidean traveling salesman problem with low gap 解决低间隙欧几里得旅行推销员问题的准线性时间启发式

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-17 DOI: 10.1016/j.jocs.2024.102424

Arno Formella

引用次数: 0

Reinforcement Twinning: From digital twins to model-based reinforcement learning 强化孪生：从数字孪生到基于模型的强化学习

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-14 DOI: 10.1016/j.jocs.2024.102421

Lorenzo Schena , Pedro A. Marques , Romain Poletti , Samuel Ahizi , Jan Van den Berghe , Miguel A. Mendez

{"title":"Reinforcement Twinning: From digital twins to model-based reinforcement learning","authors":"Lorenzo Schena , Pedro A. Marques , Romain Poletti , Samuel Ahizi , Jan Van den Berghe , Miguel A. Mendez","doi":"10.1016/j.jocs.2024.102421","DOIUrl":"10.1016/j.jocs.2024.102421","url":null,"abstract":"<div><p>The concept of digital twins promises to revolutionize engineering by offering new avenues for optimization, control, and predictive maintenance. We propose a novel framework for simultaneously training the digital twin of an engineering system and an associated control agent. The training of the twin combines methods from adjoint-based data assimilation and system identification, while the training of the control agent combines model-based optimal control and model-free reinforcement learning. The training of the control agent is achieved by letting it evolve independently along two paths: one driven by a model-based optimal control and another driven by reinforcement learning. The virtual environment offered by the digital twin is used as a playground for confrontation and indirect interaction. This interaction occurs as an “expert demonstrator”, where the best policy is selected for the interaction with the real environment and “cloned” to the other if the independent training stagnates. We refer to this framework as Reinforcement Twinning (RT). The framework is tested on three vastly different engineering systems and control tasks, namely (1) the control of a wind turbine subject to time-varying wind speed, (2) the trajectory control of flapping-wing micro air vehicles (FWMAVs) subject to wind gusts, and (3) the mitigation of thermal loads in the management of cryogenic storage tanks. The test cases are implemented using simplified models for which the ground truth on the closure law is available. The results show that the adjoint-based training of the digital twin is remarkably sample-efficient and completed within a few iterations. Concerning the control agent training, the results show that the model-based and the model-free control training benefit from the learning experience and the complementary learning approach of each other. The encouraging results open the path towards implementing the RT framework on real systems.</p></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"82 ","pages":"Article 102421"},"PeriodicalIF":3.1,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142012973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An open science grid implementation of the steady state genetic algorithm for crystal structure prediction 用于晶体结构预测的稳态遗传算法的开放科学网格实施方案

IF 3.1 3区计算机科学

Journal of Computational Science Pub Date : 2024-08-14 DOI: 10.1016/j.jocs.2024.102415

Kristal N. Varela , Gabriel I. Pagola , Albert M. Lund , Marta B. Ferraro , Anita M. Orendt , Julio C. Facelli

引用次数: 0