{"title":"DP-PINN+: A Dual-Phase PINN learning with automated phase division","authors":"Da Yan, Ligang He","doi":"10.1016/j.jocs.2025.102637","DOIUrl":"10.1016/j.jocs.2025.102637","url":null,"abstract":"<div><div>Physics-Informed Neural Networks (PINNs) are a promising application of deep neural networks for the numerical solution of nonlinear partial differential equations (PDEs). However, it has been observed that standard PINNs may not be able to accurately fit all types of PDEs, leading to poor predictions for specific regions in the domain. A common solution is to partition the domain by time and train each time interval separately. However, this approach leads to the prediction errors being accumulated over time, which is especially the case when solving “stiff” PDEs. To address these issues, we propose a new PINN training scheme, called DP-PINN+ (Dual-Phase PINN+). DP-PINN+ divides the training into two phases based on a carefully chosen time point <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span>. The phase-1 training aims to generate the accurate solution at <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span>, which will serve as the additional intermediate condition for the phase-2 training. The method for determining the optimized value of <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>s</mi></mrow></msub></math></span> is proposed in this paper. Further,new sampling strategies are proposed to enhance the training process. These design considerations improve the prediction accuracy significantly. We have conducted the experiments to evaluate DP-PINN+ with both “stiff” and non-stiff PDEs, including 1D Burger’s Equation, 1D Allen–Cahn Equation, 2D and 3D Navier–Stokes Equations (i.e., 2D cylinder wake and 3D unsteady Beltrami flow). We compared DP-PINN+ with the state-of-the-art PINNs in literature, including Time Adaptive PINN, SA-PINN, bc-PINN and NSFNets.The results show that the solutions predicted by DP-PINN+ exhibit significantly higher accuracy. This paper is extended from our conference paper published in ICCS2024 Yan and He (2024) <span><span>[1]</span></span>.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102637"},"PeriodicalIF":3.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322595","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}
{"title":"Unconditionally stable method for the high-order Allen–Cahn equation","authors":"Seungyoon Kang, Youngjin Hwang, Junseok Kim","doi":"10.1016/j.jocs.2025.102636","DOIUrl":"10.1016/j.jocs.2025.102636","url":null,"abstract":"<div><div>We propose an unconditionally stable algorithm for the Allen–Cahn (AC) equation that incorporates a high-order free energy. The high-order AC equation improves the preservation of interfacial dynamics and suppresses noise. The proposed method guarantees unconditional stability, which is essential for precise phase transition modeling and preserving detailed characteristics. To effectively solve the governing equation, it is divided into two subproblems, each of which is solved separately. The nonlinear operator is handled using a frozen coefficient method, followed by a closed-form solution. The linear operator is solved by applying the discrete cosine transform. To verify the effectiveness of the proposed algorithm, we carried out various computational simulations in two- and three-dimensional space. The proposed method ensures unconditional stability, and therefore allows stable solutions even with relatively large time steps. Moreover, we investigate the notable characteristics of the high-order AC equation, particularly its enhanced capability to effectively handle phase separation phenomena in the presence of significant noise and complex phase interfaces.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102636"},"PeriodicalIF":3.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241866","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}
Zhiming Li , Shuangshuang Wu , Wenbai Chen , Fuchun Sun
{"title":"Physics-informed neural networks for compliant robotic manipulators dynamic modeling","authors":"Zhiming Li , Shuangshuang Wu , Wenbai Chen , Fuchun Sun","doi":"10.1016/j.jocs.2025.102633","DOIUrl":"10.1016/j.jocs.2025.102633","url":null,"abstract":"<div><div>Deep learning is widely used in robotics, yet often overlooks key physical principles in dynamic modeling, leading to a lack of interpretability and generalization. To address this issue, recent innovations have introduced physics-informed neural networks (PINNs), which integrate fundamental physics into deep learning and offer significant advantages in modeling rigid-body dynamics. This study focuses on the application of PINNs to model compliant robotic manipulators. This requires extending PINNs to handle complex compliant dynamics. We propose an augmented PINN model capable of comprehensively learning manipulator dynamics, including compliant components. The model is tested on dynamic modeling of two physical compliant manipulators and a simulated manipulator. The results highlight its exceptional precision and generalization across a wide range of robotic systems, from purely rigid to compliant structures.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102633"},"PeriodicalIF":3.1,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261851","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}
Murside Degirmenci , Murat Surucu , Matjaž Perc , Yalcin Isler
{"title":"Convolutional neural networks can diagnose schizophrenia","authors":"Murside Degirmenci , Murat Surucu , Matjaž Perc , Yalcin Isler","doi":"10.1016/j.jocs.2025.102634","DOIUrl":"10.1016/j.jocs.2025.102634","url":null,"abstract":"<div><div>Schizophrenia is a severe mental disorder that affects how individuals think, perceive, and behave, often making accurate and timely diagnosis a significant challenge for clinicians. Traditional diagnostic approaches, such as interviews and psychological tests, have limitations in capturing the complex neurological underpinnings of the condition. In recent years, machine learning and deep learning techniques have shown promise in improving diagnostic accuracy across a variety of medical domains. However, relatively few studies have applied these methods to schizophrenia diagnosis, despite their potential. In this study, we investigate whether convolutional neural networks can effectively diagnose schizophrenia using publicly available EEG data. We achieved classification accuracies of 98.26% in subject-independent settings and 91.21% in subject-dependent settings on the test data, using a fully connected layer based on a Multi-Layer Perceptron classifier. These results appear promising when compared to the current state of the art.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102634"},"PeriodicalIF":3.1,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221841","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}
{"title":"A MATLAB code for finding the kernel of a simple polygon","authors":"Annamaria Mazzia","doi":"10.1016/j.jocs.2025.102616","DOIUrl":"10.1016/j.jocs.2025.102616","url":null,"abstract":"<div><div>This paper presents an algorithm for determining the kernel of a simple polygon. Traditional algorithms typically define the kernel by intersecting carefully chosen half-planes. In contrast, we explore a less-used approach as described in Zhao and Wang, (2010) , that handles concave vertices of the polygon as part of the kernel computation. This approach leverages two key techniques. First, it intersects the polygon’s interior with lines passing through edges adjacent to concave vertices. Second, it analyzes the orientations of two specific triangles identified by the sequence of vertices defining the line segment’s endpoints. This method for ray-line segment intersection plays a crucial role in efficiently determining the kernel. While the original approach effectively determines the kernel for a subset of simple polygons, it has limitations in handling all possible cases. This paper addresses these limitations by presenting a refined algorithm that expands the applicability of the method. The enhanced algorithm is implemented in MATLAB and validated through extensive testing to ensure its accuracy and efficiency.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102616"},"PeriodicalIF":3.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205426","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}
{"title":"Enhanced metabolite-disease associations prediction via Neighborhood Aggregation Graph Transformer with Kolmogorov–Arnold Networks","authors":"Pengli Lu , Jian Zhang , Wenzhi Liu , Fentang Gao","doi":"10.1016/j.jocs.2025.102629","DOIUrl":"10.1016/j.jocs.2025.102629","url":null,"abstract":"<div><div>Metabolites are essential products of cellular chemical reactions, critical for sustaining life and reproduction. Research shows that metabolite concentrations in patients differ from those in healthy individuals, making metabolite-based disease prediction crucial for diagnosis and treatment. To address the limitations of current computational methods in accuracy and interpretability, we propose a novel Neighborhood Aggregation Graph Transformer method (AGKphormer). This method enhances link relationships by optimizing the minimum nuclear norm using the Alternating Direction Method of Multipliers (ADMM) and incorporates Fast Kolmogorov–Arnold Networks (FastKAN) to improve both accuracy and interpretability. We first construct a heterogeneous network based on the correlation and similarity between metabolites and diseases. Then, we utilize the ADMM algorithm to enhance link relationships by solving the minimum nuclear norm, reducing sparse relationships between nodes and providing richer features for neural network learning. For the features learned by the graph convolutional network (GCN), we employ a Graph Transformer augmented with FastKAN to learn long-range dependencies. This approach enables global feature embedding and addresses GCN’s smoothness issue while enhancing interpretability. Through five-fold cross-validation, AGKphormer achieved average AUC and AUPR values of 97.32% and 97.34%, respectively, outperforming most methods and demonstrating its effectiveness in predicting disease-related metabolites. Additionally, case studies further confirm that AGKphormer is a reliable tool for discovering potential metabolites.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102629"},"PeriodicalIF":3.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241865","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}
{"title":"Deep Ritz method with Fourier feature mapping: A deep learning approach for solving variational models of microstructure","authors":"Ensela Mema , Ting Wang , Jaroslaw Knap","doi":"10.1016/j.jocs.2025.102631","DOIUrl":"10.1016/j.jocs.2025.102631","url":null,"abstract":"<div><div>This paper presents a novel approach that combines the Deep Ritz Method (DRM) with Fourier feature mapping to solve minimization problems comprised of multi-well, non-convex energy potentials. These problems present computational challenges as they lack a global minimum. Through an investigation of three benchmark problems in both 1D and 2D, we observe that DRM suffers from spectral bias pathology, limiting its ability to learn solutions with high frequencies. To overcome this limitation, we modify the method by introducing Fourier feature mapping. This modification involves applying a Fourier mapping to the input layer before it passes through the hidden and output layers. Our results demonstrate that Fourier feature mapping enables DRM to generate high-frequency, multiscale solutions for the benchmark problems in both 1D and 2D, offering a promising advancement in tackling complex non-convex energy minimization problems.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"91 ","pages":"Article 102631"},"PeriodicalIF":3.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579930","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}
César Magno Leite de Oliveira Júnior , Antonio Mauro Saraiva , Alexandre Cláudio Botazzo Delbem , Haroldo Fraga de Campos Velho , Gerônimo Gallarreta Zubiaurre Lemos , Fabrício Pereira Härter
{"title":"Data assimilation by cellular neural network applied to Lorenz-63 system","authors":"César Magno Leite de Oliveira Júnior , Antonio Mauro Saraiva , Alexandre Cláudio Botazzo Delbem , Haroldo Fraga de Campos Velho , Gerônimo Gallarreta Zubiaurre Lemos , Fabrício Pereira Härter","doi":"10.1016/j.jocs.2025.102587","DOIUrl":"10.1016/j.jocs.2025.102587","url":null,"abstract":"<div><div>Data assimilation is an important process to compute the best initial condition for a computational prediction system, combining a previous prediction (<em>background</em>) with observation. The result from this procedure is the computed <em>analysis</em>. A cellular neural network (Cell-NN) is applied as a data assimilation (DA) method. The Cell-NN is also employed to integrate dynamic systems in time. Different Cell-NN configurations are developed for the DA process and as an integration scheme. The Lorenz system under a chaotic dynamical regime is used for testing with Cell-NN. Data assimilation with the 3D variational (3D-Var) method is also implemented for comparison. Cell-NN belongs to the class of unsupervised neural networks. The performance for computing the analysis by Cell-NN presented a similar error magnitude to the 3D-Var technique.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102587"},"PeriodicalIF":3.1,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241864","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}
Jie Wu , Xiaoyi Zhang , Xisheng Zhan , Tao Han , Huaicheng Yan
{"title":"Adaptive time-varying output formation tracking control for multi-agent system with dynamic event-triggered strategies","authors":"Jie Wu , Xiaoyi Zhang , Xisheng Zhan , Tao Han , Huaicheng Yan","doi":"10.1016/j.jocs.2025.102630","DOIUrl":"10.1016/j.jocs.2025.102630","url":null,"abstract":"<div><div>This paper investigates the output feedback time-varying formation(OFTVF) tracking issue for general linear multi-agent systems(MASs). To address this issue, novel dynamic event-triggered(DET) strategies are proposed to manage the inter-agent communication effectively. It removes the assumption that constant interaction is required between agents, and therefore communication cost is reduced significantly. Then under the proposed DET strategies, an adaptive OFTVF tracking control algorithms is designed for general linear MASs. Using Lyapunov stability theory, it is demonstrated that under proper conditions the proposed protocol is implementable. Furthermore, for the constructed DET scheme, no agent exhibit the Zeno behavior. Simulation example is presented at the end of the paper to demonstrate the effectiveness of designed DET control mechanism.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102630"},"PeriodicalIF":3.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205425","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}
Yan Zhao , Xin He , Junliang Shang , Daohui Ge , Jin-Xing Liu
{"title":"AGDFCDA: Adaptive graph convolutional network and dual feature for circRNA-disease association prediction","authors":"Yan Zhao , Xin He , Junliang Shang , Daohui Ge , Jin-Xing Liu","doi":"10.1016/j.jocs.2025.102615","DOIUrl":"10.1016/j.jocs.2025.102615","url":null,"abstract":"<div><div>Circular RNA (circRNA) is a special type of RNA molecule whose structure presents as a closed loop. Numerous studies have demonstrated that abnormal expression of circRNA is closely associated with the development of diverse diseases. Accurately predicting the association between the circRNA and disease is important for understanding the pathogenesis of disease and discovering potential biomarkers. However, the high cost and complexity of traditional biological experiments limit the development of research. By constructing computational models and performing bioinformatics analysis, it is possible to identify disease-related circRNA more efficiently and reveal its potential mechanism. This paper presents AGDFCDA, a computational model for circRNA-disease association prediction, featuring a dual feature extraction strategy. On the one hand, the strategy applies the fully connected neural network to reduce the redundant information in the initial features, while the hidden information of circRNA and disease is preliminarily extracted. On the other hand, the strategy introduces adaptive graph convolutional network to learn more comprehensive representation of circRNA and disease to realize further extraction of features. AGDFCDA is assessed using five-fold cross-validation, and the results indicate that it outperforms the comparison methods in predicting circRNA-disease associations. In addition, the results of case studies can provide reliable candidate circRNA for wet experiments to be carried out with effective cost savings.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"90 ","pages":"Article 102615"},"PeriodicalIF":3.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144213482","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}