{"title":"R-FAST: Robust Fully-Asynchronous Stochastic Gradient Tracking Over General Topology","authors":"Zehan Zhu;Ye Tian;Yan Huang;Jinming Xu;Shibo He","doi":"10.1109/TSIPN.2024.3444484","DOIUrl":"https://doi.org/10.1109/TSIPN.2024.3444484","url":null,"abstract":"We propose a Robust Fully-Asynchronous Stochastic Gradient Tracking method (R-FAST) for distributed machine learning problems over a network of nodes, where each node performs local computation and communication at its own pace without any form of synchronization. Different from existing asynchronous distributed algorithms, R-FAST can eliminate the impact of data heterogeneity across nodes on convergence performance and allow for packet losses by employing a robust gradient tracking strategy that relies on properly designed auxiliary variables for tracking and buffering the overall gradient vector. Moreover, the proposed method utilizes two spanning-tree graphs for communication so long as both share at least one common root, enabling flexible designs in communication topologies. We show that R-FAST converges in expectation to a neighborhood of the optimum with a geometric rate for smooth and strongly convex objectives; and to a stationary point with a sublinear rate for general non-convex problems. Extensive experiments demonstrate that R-FAST runs 1.5-2 times faster than synchronous benchmark algorithms, such as Ring-AllReduce and D-PSGD, while still achieving comparable accuracy, and outperforms the existing well-known asynchronous algorithms, such as AD-PSGD and OSGP, especially in the presence of stragglers.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"665-678"},"PeriodicalIF":3.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173995","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":"Distributed Nash Equilibrium Seeking for Nonlinear Players With Input Delay","authors":"Zhaoming Sheng;Qian Ma","doi":"10.1109/TSIPN.2024.3451979","DOIUrl":"https://doi.org/10.1109/TSIPN.2024.3451979","url":null,"abstract":"This paper studies the distributed Nash equilibrium seeking problem for players subject to unknown nonlinear dynamics and input delay. By designing a distributed estimator for each player to estimate other players' decisions and embedding an auxiliary variable to compensate for the influence of unknown nonlinearities, the distributed Nash equilibrium seeking algorithms are obtained for first-, second-, and high-order nonlinear players, respectively. With the help of the Lyapunov stability theory and Lyapunov-Krasovskii functional approach, the maximum allowable input delay is determined and the global asymptotic convergence of players' decisions to the Nash equilibrium is proved. Finally, simulation examples are provided to demonstrate the effectiveness of the proposed methods.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"679-689"},"PeriodicalIF":3.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174011","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":"Stable Outlier-Robust Signal Recovery Over Networks: A Convex Analytic Approach Using Minimax Concave Loss","authors":"Maximilian H. V. Tillmann;Masahiro Yukawa","doi":"10.1109/TSIPN.2024.3451992","DOIUrl":"10.1109/TSIPN.2024.3451992","url":null,"abstract":"This paper presents a mathematically rigorous framework of remarkably-robust signal recovery over networks. The proposed framework is based on the \u0000<italic>minimax concave (MC)</i>\u0000 loss, which is a weakly convex function so that it attains i) remarkable outlier-robustness and ii) guarantee of convergence to a solution of the posed problem. We present a novel problem formulation which involves an auxiliary vector so that the formulation accommodates statistical properties of signal, noise, and outliers. We show the conditions to guarantee convexity of the local and global objectives. Via reformulation, the distributed triangularly preconditioned primal-dual algorithm is applied to the posed problem. The numerical examples show that our proposed formulation exhibits remarkable robustness under devastating outliers as well as outperforming the existing methods. Comparisons between the local and global convexity conditions are also presented.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"690-705"},"PeriodicalIF":3.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142182551","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":"Barycentric Coordinate-Based Distributed Localization Over 3-D Underwater Wireless Sensor Networks","authors":"Lei Shi;Shaojie Yao;Nianwen Ning;Yi Zhou","doi":"10.1109/TSIPN.2024.3440644","DOIUrl":"10.1109/TSIPN.2024.3440644","url":null,"abstract":"Accurate localization of underwater wireless sensor networks (UWSNs) are essential for their seamless integration and operational efficacy in marine environments, yet it poses a considerable technical challenge due to the distinctive limitations of underwater communications. This paper addresses the intricate 3-D localization problem for UWSNs by proposing an innovative method based on barycentric coordinates and relative distance measurements. In order to adapt to the influence of underwater communication constraints, a barycentric coordinate-based distributed iterative localization method combining with the processing of underwater background noise is proposed. It is proved theoretically that the proposed method can almost guarantee the convergence to the exact location of each underwater sensor node. Finally, the effectiveness of the proposed localization method is verified by numerical simulations. The proposed localization scheme requires only small number of anchor nodes, thus facilitating the development of broader and more cost-effective underwater localization systems.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"640-649"},"PeriodicalIF":3.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945156","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":"Causal Learning and Knowledge Fusion Mechanism for Brain Functional Network Classification","authors":"Junzhong Ji;Feipeng Wang;Lu Han;Jinduo Liu","doi":"10.1109/TSIPN.2024.3430474","DOIUrl":"10.1109/TSIPN.2024.3430474","url":null,"abstract":"Current studies have shown that the classification of human brain functional networks (BFN) is a reliable way to diagnose and predict brain diseases. However, a great challenge for current traditional machine learning methods and deep learning methods is their poor performance or lack of interpretability. To alleviate this problem, we propose a novel causal learning and knowledge fusion mechanism for brain functional network classification, named CLKF. The proposed mechanism first extracts causal relationships among brain regions from functional magnetic resonance imaging (fMRI) data using partial correlation and conditional mutual information, and obtains the relationships between BFN and labels by Gaussian kernel density estimation. Then, it fuses these two types of relationships as knowledge to aid in the classification of brain functional networks. The experimental results on the simulated resting-state fMRI dataset show that the proposed mechanism can effectively learn the causal relationships among brain regions. The results on the real resting-state fMRI dataset demonstrate that our mechanism can not only improve the classification performance of both traditional machine learning and deep learning methods but also provide an interpretation of the results obtained by deep learning methods. These findings suggest that the proposed mechanism has good potential in practical medical applications.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"650-664"},"PeriodicalIF":3.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745272","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":"Distributed Constrained Optimization Algorithm for Higher-Order Multi-Agent Systems","authors":"Xiasheng Shi;Lingfei Su;Qing Wang","doi":"10.1109/TSIPN.2024.3430492","DOIUrl":"10.1109/TSIPN.2024.3430492","url":null,"abstract":"The distributed nonsmooth constrained optimization problems over higher-order systems are investigated in this study. The challenges lies in the fact that the output of the agent is directly controlled by the state variable rather than the control input. Compared to existing works, the local objective function is merely assumed to be nonsmooth. Firstly, an initialization-free fully distributed derivative feedback control scheme is developed for the known objective function over double-integrator systems. The local generic constraint is addressed by an adaptive nonnegative penalty factor. Secondly, an initialization-free fully distributed state feedback control scheme is proposed for the unknown objective function over double-integrator systems. Addressing the local box constraint involves incorporating an adaptive penalty factor. Thirdly, the above two algorithms are extended to the general higher-order systems using the tracking control method. In addition, the above-developed methods are proved to be asymptotically convergent under certain conditions. Eventually, the efficiency of the above-produced methods is shown via four simulation cases.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"626-639"},"PeriodicalIF":3.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745314","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":"Distributed Convex Optimization “Over-the-Air” in Dynamic Environments","authors":"Navneet Agrawal;Renato Luís Garrido Cavalcante;Masahiro Yukawa;Sławomir Stańczak","doi":"10.1109/TSIPN.2024.3423668","DOIUrl":"10.1109/TSIPN.2024.3423668","url":null,"abstract":"This paper presents a decentralized algorithm for solving distributed convex optimization problems in dynamic networks with time-varying objectives. The unique feature of the algorithm lies in its ability to accommodate a wide range of communication systems, including previously unsupported ones, by abstractly modeling the information exchange in the network. Specifically, it supports a novel communication protocol based on the “over-the-air” function computation (OTA-C) technology, that is designed for an efficient and truly decentralized implementation of the consensus step of the algorithm. Unlike existing OTA-C protocols, the proposed protocol does not require the knowledge of network graph structure or channel state information, making it particularly suitable for decentralized implementation over ultra-dense wireless networks with time-varying topologies and fading channels. Furthermore, the proposed algorithm synergizes with the “superiorization” methodology, allowing the development of new distributed algorithms with enhanced performance for the intended applications. The theoretical analysis establishes sufficient conditions for almost sure convergence of the algorithm to a common time-invariant solution for all agents, assuming such a solution exists. Our algorithm is applied to a real-world distributed random field estimation problem, showcasing its efficacy in terms of convergence speed, scalability, and spectral efficiency. Furthermore, we present a superiorized version of our algorithm that achieves faster convergence with significantly reduced energy consumption compared to the unsuperiorized algorithm.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"610-625"},"PeriodicalIF":3.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141577659","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":"Memory-Based Accelerated Consensus for Second-Order Multi-Agent Systems With Delay","authors":"Mengya Huang;Jing-Wen Yi;Li Chai","doi":"10.1109/TSIPN.2024.3417225","DOIUrl":"https://doi.org/10.1109/TSIPN.2024.3417225","url":null,"abstract":"Time delay, which is particularly common in reality, generally has a negative impact on system performance. In order to improve the convergence rate, memory term is adopt to design the fast consensus protocol for second-order multi-agent systems(MASs) with time delay. Through the graph Fourier transform, the consensus problem is transformed to a simultaneous stability problem, and the necessary and sufficient condition to reach consensus is given. Then, a fast consensus algorithm based on gradient descent is proposed to optimize the convergence rate. For MASs with small delay, the explicit formulas of the optimal control gains and the fastest convergence rate are obtained for memory-based and memoryless protocols respectively. Finally, numerical examples are given to illustrate the validity of the theoretical results.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"574-583"},"PeriodicalIF":3.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543991","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":"Distributed Control in Uncertain Nonlinear Multiagent Systems Under Event-Triggered Communication and General Directed Graphs","authors":"Gang Wang;Zongyu Zuo;Peng Li","doi":"10.1109/TSIPN.2024.3422878","DOIUrl":"10.1109/TSIPN.2024.3422878","url":null,"abstract":"Designing a consensus algorithm for multiagent systems within an event-triggered communication setting is challenging due to the discontinuous and inaccurate interaction information caused by event-triggering mechanisms. Currently, most related results require an undirected or balanced directed graph. To avoid such restrictive requirements and consider general directed graphs with a spanning tree, we first investigate the perturbed consensus problem of first-order dynamics. Then, we extend our findings to address the consensus problem of the uncertain nonlinear multiagent systems described in Lagrangian dynamics, Brunovsky dynamics, and strict-feedback dynamics under event-triggered communication. We develop three distributed consensus protocols that consider the unique characteristics of these systems and assign different reference signals accordingly. Our proposed schemes ensure that consensus errors either converge to zero or to a small adjustable neighborhood around zero without Zeno behavior while preserving signal boundedness in the closed-loop system. Finally, we conduct extensive simulations to further illustrate the efficiency of our theoretical results.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"599-609"},"PeriodicalIF":3.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547847","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":"Fully Distributed Model-Free Flocking of Multiple Euler-Lagrange Systems","authors":"Mingkang Long;Yin Chen;Housheng Su","doi":"10.1109/TSIPN.2024.3419437","DOIUrl":"https://doi.org/10.1109/TSIPN.2024.3419437","url":null,"abstract":"In this paper, we investigate the leader-follower flocking issue of multiple Euler-Lagrange systems (MELSs) with time-varying input disturbances and completely unknown model parameter information under a proximity graph. Particularly, each follower can only access information from other agents that the relative distance between them is not greater than communication distance. Firstly, based on adaptive control theory, we propose a model-free leader-follower flocking algorithm with constant coupling gains, that is the controller design does not require any dynamic parameter information. Then, for fully distributed design (i.e. no requirement for any global information of the communication graph), edge-based adaptive coupling gains are applied for the above algorithm. The leader-follower flocking of MELSs can be achieved by all proposed algorithms under a connected and no-collision initial proximity graph. Finally, we show some simulation results to illustrate the effectiveness of all proposed flocking algorithms.","PeriodicalId":56268,"journal":{"name":"IEEE Transactions on Signal and Information Processing over Networks","volume":"10 ","pages":"565-573"},"PeriodicalIF":3.0,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141495268","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}