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采用改进投影梯度非负矩阵分解和非采样Contourlet变换的图像融合方法 被引量:20
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作者 杨粤涛 朱明 +1 位作者 贺柏根 高文 《光学精密工程》 EI CAS CSCD 北大核心 2011年第5期1143-1150,共8页
针对非负矩阵分解(NMF)算法时间复杂度较高,而投影梯度(PG)优化方法可以大幅降低NMF约束优化迭代问题的时间复杂度,提出一种基于改进的投影梯度NMF(IPGNMF)和非采样Contourlet变换(NSCT)相结合的图像融合方法。采用NSCT对已配准的源图... 针对非负矩阵分解(NMF)算法时间复杂度较高,而投影梯度(PG)优化方法可以大幅降低NMF约束优化迭代问题的时间复杂度,提出一种基于改进的投影梯度NMF(IPGNMF)和非采样Contourlet变换(NSCT)相结合的图像融合方法。采用NSCT对已配准的源图像进行多尺度、多方向的分解,将分解后的低频部分作为原始数据,利用IPGNMF得到包含特征基的低通子带系数;高频部分应用了一种基于邻域一致性测度(NHM)的局部自适应融合规则得到各带通方向子带系数。经过NSCT逆变换得到融合图像。实验结果表明,融合结果在主观和客观评价上均优于NSWT方法、IPGNMF方法和NSCT方法。与NSCT法相比,实验所采用的两组图像的信息熵、清晰度和Q指标分别提高了0.0627%、0.901%、3.120 1%和2.769%、2.203%、1.049%。 展开更多
关键词 图像融合 非负矩阵分解 投影梯度 非采样CONTOURLET变换
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基于投影梯度的非负矩阵分解盲信号分离算法 被引量:7
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作者 李煜 何世钧 《计算机工程》 CAS CSCD 北大核心 2016年第2期104-107,112,共5页
在盲信号分离过程中,基于乘性迭代的非负矩阵分解(NMF)存在运算量大、收敛速度慢等问题。为此,在投影梯度法的基础上提出一种新的NMF盲信号分离算法。通过增加行列式约束、稀疏度约束和相关性约束条件,将最优化问题转化为交替的最小二... 在盲信号分离过程中,基于乘性迭代的非负矩阵分解(NMF)存在运算量大、收敛速度慢等问题。为此,在投影梯度法的基础上提出一种新的NMF盲信号分离算法。通过增加行列式约束、稀疏度约束和相关性约束条件,将最优化问题转化为交替的最小二乘问题,将投影梯度法应用于基于约束的NMF盲信号分离过程。仿真结果表明,该算法能减小重构误差,在维持源分离信号稀疏性的基础上实现混合信号的唯一分解。与经典NMF算法和NMFDSC算法相比,其收敛和分解速度更快,重构信号的信噪比更高。 展开更多
关键词 盲信号分离 非负矩阵分解 乘性迭代 交替最小二乘法 投影梯度
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Distributed Nash Equilibrium Seeking Strategies Under Quantized Communication 被引量:2
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作者 Maojiao Ye Qing-Long Han +2 位作者 Lei Ding Shengyuan Xu Guobiao Jia 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期103-112,共10页
This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achi... This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achieve the optimization o players' objective functions while restricting their actions within required non-empty, convex and compact domains. In addition, a leader-following consensus protocol, in which quantized informa tion flows are utilized, is employed for information sharing among players. More specifically, logarithmic quantizers and uniform quantizers are investigated under both undirected and connected communication graphs and strongly connected digraphs, respec tively. Through Lyapunov stability analysis, it is shown that play ers' actions can be steered to a neighborhood of the Nash equilib rium with logarithmic and uniform quantizers, and the quanti fied convergence error depends on the parameter of the quan tizer for both undirected and directed cases. A numerical exam ple is given to verify the theoretical results. 展开更多
关键词 CONSENSUS distributed Nash equilibrium seeking projected gradient play quantized communication
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求解界约束优化问题的有效集算法综述 被引量:5
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作者 闫秀娟 王永丽 贺国平 《数学的实践与认识》 CSCD 北大核心 2012年第3期100-107,共8页
主要介绍了求解界约束优化问题的有效集方法,包括投影共轭梯度法和有效集识别函数法,讨论了各自的优点和不足.最后,指出了有效集法的研究趋势及应用前景.
关键词 界约束优化问题 有效集 投影梯度 共轭梯度 识别函数
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ANonmonotone Projected Gradient Method for Multiobjective Problems on Convex Sets
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作者 Gabrie Anibal Carrizo Nadia Soledad Fazzio Maria Laura Schuverdt 《Journal of the Operations Research Society of China》 EI CSCD 2024年第2期410-427,共18页
In this work we consider an extension of the classical scalar-valued projected gradient method for multiobjective problems on convex sets.As in Fazzio et al.(Optim Lett 13:1365-1379,2019)a parameter which controls the... In this work we consider an extension of the classical scalar-valued projected gradient method for multiobjective problems on convex sets.As in Fazzio et al.(Optim Lett 13:1365-1379,2019)a parameter which controls the step length is considered and an updating rule based on the spectral gradient method from the scalar case is proposed.In the present paper,we consider an extension of the traditional nonmonotone approach of Grippo et al.(SIAM J Numer Anal 23:707-716,1986)based on the maximum of some previous function values as suggested in Mita et al.(J Glob Optim 75:539-559,2019)for unconstrained multiobjective optimization problems.We prove the accumulation points of sequences generated by the proposed algorithm,if they exist,are stationary points of the original problem.Numerical experiments are reported. 展开更多
关键词 Multiobjective optimization projected gradient methods Nonmonotone line search Global convergence
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Distributed Nash Equilibrium Seeking on Compact Action Sets over Jointly Strongly Connected Switching Networks
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作者 HE Xiongnan HUANG Jie 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2024年第1期63-81,共19页
This paper studies the distributed Nash equilibrium seeking(DNES)problem for games whose action sets are compact and whose network graph is switching satisfying the jointly strongly connected condition.To keep the act... This paper studies the distributed Nash equilibrium seeking(DNES)problem for games whose action sets are compact and whose network graph is switching satisfying the jointly strongly connected condition.To keep the actions of all players in their action sets all the time,one has to resort to the projected gradient-based method.Under the assumption that the unique Nash equilibrium is the unique equilibrium of the pseudogradient system,an algorithm is proposed that is able to exponentially find the Nash equilibrium.Further,the authors also consider the distributed Nash equilibrium seeking problem for games whose actions are governed by high-order integrator dynamics and belong to some compact sets.Two examples are used to illustrate the proposed approach. 展开更多
关键词 Compact action sets jointly strongly connected switching graphs Nash equilibrium seeking projected gradient-based algorithm.
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基于快速非负矩阵分解和RBF网络的高光谱图像分类算法 被引量:3
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作者 狄文羽 何明一 梅少辉 《遥感技术与应用》 CSCD 北大核心 2009年第3期385-390,共6页
提出一种处理AVIRIS高光谱图像数据的计算机分类算法。首先采用投影梯度(ProjectedGradient)改进的非负矩阵分解(NMF)方法对高光谱数据进行特征提取,大大降低了分解过程中两个子迭代问题的时间复杂度,而后利用径向基函数神经网络(RBFNN... 提出一种处理AVIRIS高光谱图像数据的计算机分类算法。首先采用投影梯度(ProjectedGradient)改进的非负矩阵分解(NMF)方法对高光谱数据进行特征提取,大大降低了分解过程中两个子迭代问题的时间复杂度,而后利用径向基函数神经网络(RBFNN)分类器对提取结果进行分类。结果表明,与传统NMF和主成分分析相比,PGNMF-RBF算法消耗时间最少,分类精度最高,6类地物的分类精度达到83.34%。该算法在保留非负矩阵分解明确物理意义的基础上,获得了更快的分解速度和更高的分类精度,在高光谱图像分类领域具有较大的应用潜力。 展开更多
关键词 投影梯度 非负矩阵分解 RBF神经网络 图像分类
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CONVERGENCE PROPERTIES OF PROJECTED GRADIENT METHODS WITH NONMONOTONIC BACK TRACKING TECHNIQUE FOR CONVEX CONSTRAINED OPTIMIZATION 被引量:2
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作者 ZHU Detong (Department of Mathematics, Shanghai Normal University, Shanghai 200234, China) 《Systems Science and Mathematical Sciences》 SCIE EI CSCD 2000年第4期407-424,共18页
This paper proposes projected gradient algorithms in association with using both trust region and line search techniques for convex constrained optimization problems. The mixed strategy is adopted which switches to ba... This paper proposes projected gradient algorithms in association with using both trust region and line search techniques for convex constrained optimization problems. The mixed strategy is adopted which switches to back tracking steps when a trial projected gradient step produced by the trust region subproblem is unacceptable. A nonmonotone criterion is used to speed up the convergence progress in some curves with large curvature. A theoretical analysis is given which proves that the proposed algorithms are globally convergent and have local superlinear convergence rate under some reasonable conditions. The results of numerical experiments are reported to show the effectiveness of the proposed algorithms. 展开更多
关键词 Line search TRUST region projected gradient NONMONOTONE TECHNIQUE CONVEX constrained optimization.
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基于投影梯度及下逼近方法的非负矩阵分解 被引量:3
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作者 叶军 《计算机工程》 CAS CSCD 2012年第3期200-202,共3页
在非负矩阵分解算法中,为提升基矩阵的稀疏表达能力,在不事先设定稀疏度的情形下,提出一种基于投影梯度及下逼近方法的非负矩阵分解算法——PGNMU。通过引入上界的约束条件,利用基于投影梯度的交替迭代方法提取基矩阵的重要特征并加以... 在非负矩阵分解算法中,为提升基矩阵的稀疏表达能力,在不事先设定稀疏度的情形下,提出一种基于投影梯度及下逼近方法的非负矩阵分解算法——PGNMU。通过引入上界的约束条件,利用基于投影梯度的交替迭代方法提取基矩阵的重要特征并加以应用。在人脸数据库CBCL和ORL上的实验结果表明,该方法能改进基矩阵的稀疏描述能力,且其识别率也优于已有方法。 展开更多
关键词 非负矩阵分解 投影梯度 下逼近 松弛法 稀疏度 基矩阵
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梯度投影算子的广义陡度引理及其应用 被引量:1
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作者 王长钰 夏尊铨 王宜举 《数学学报(中文版)》 SCIE CSCD 北大核心 2003年第2期251-260,共10页
在一般闭凸集上建立了梯度投影算子的广义陡度引理,利用它证明了几种松 弛搜索下梯度投影算法的全局收敛性、强收敛性以及若干良好的收敛性质.
关键词 梯度投影算子 投影梯度 陡度引理 松弛搜索 收敛性 约束最优化问题
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A projected gradient method with nonmonotonic backtracking technique for solving convex constrained monotone variational inequality problem
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作者 WANG Yun-juan ZHU De-tong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2008年第4期463-474,共12页
Based on a differentiable merit function proposed by Taji, et al in “Mathematical Programming, 1993, 58: 369-383”, a projected gradient trust region method for the monotone variational inequality problem with conve... Based on a differentiable merit function proposed by Taji, et al in “Mathematical Programming, 1993, 58: 369-383”, a projected gradient trust region method for the monotone variational inequality problem with convex constraints is presented. Theoretical analysis is given which proves that the proposed algorithm is globally convergent and has a local quadratic convergence rate under some reasonable conditions. The results of numerical experiments are reported to show the effectiveness of the proposed algorithm. 展开更多
关键词 trust region line search projected gradient variational inequality
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Adaptive projected gradient thresholding methods for constrained l0problems 被引量:2
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作者 ZHAO ZhiHua XU FengMin LI XiangYang 《Science China Mathematics》 SCIE CSCD 2015年第10期2205-2224,共20页
In this paper, we propose and analyze adaptive projected gradient thresholding(APGT) methods for finding sparse solutions of the underdetermined linear systems with equality and box constraints. The general convergenc... In this paper, we propose and analyze adaptive projected gradient thresholding(APGT) methods for finding sparse solutions of the underdetermined linear systems with equality and box constraints. The general convergence will be demonstrated, and in addition, the bound of the number of iterations is established in some special cases. Under suitable assumptions, it is proved that any accumulation point of the sequence generated by the APGT methods is a local minimizer of the underdetermined linear system. Moreover, the APGT methods, under certain conditions, can find all s-sparse solutions for accurate measurement cases and guarantee the stability and robustness for flawed measurement cases. Numerical examples are presented to show the accordance with theoretical results in compressed sensing and verify high out-of-sample performance in index tracking. 展开更多
关键词 projected gradient l0 constraints compressed sensing index tracking hard thresholding
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Convergence analysis of projected gradient descent for Schatten-p nonconvex matrix recovery 被引量:2
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作者 CAI Yun LI Song 《Science China Mathematics》 SCIE CSCD 2015年第4期845-858,共14页
The matrix rank minimization problem arises in many engineering applications. As this problem is NP-hard, a nonconvex relaxation of matrix rank minimization, called the Schatten-p quasi-norm minimization(0 < p <... The matrix rank minimization problem arises in many engineering applications. As this problem is NP-hard, a nonconvex relaxation of matrix rank minimization, called the Schatten-p quasi-norm minimization(0 < p < 1), has been developed to approximate the rank function closely. We study the performance of projected gradient descent algorithm for solving the Schatten-p quasi-norm minimization(0 < p < 1) problem.Based on the matrix restricted isometry property(M-RIP), we give the convergence guarantee and error bound for this algorithm and show that the algorithm is robust to noise with an exponential convergence rate. 展开更多
关键词 low rank matrix recovery nonconvex matrix recovery projected gradient descent restricted isometry property
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Minimum distance constrained nonnegative matrix factorization for hyperspectral data unmixing 被引量:2
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作者 于钺 SunWeidong 《High Technology Letters》 EI CAS 2012年第4期333-342,共10页
This paper considers a problem of unsupervised spectral unmixing of hyperspectral data. Based on the Linear Mixing Model ( LMM), a new method under the framework of nonnegative matrix fac- torization (NMF) is prop... This paper considers a problem of unsupervised spectral unmixing of hyperspectral data. Based on the Linear Mixing Model ( LMM), a new method under the framework of nonnegative matrix fac- torization (NMF) is proposed, namely minimum distance constrained nonnegative matrix factoriza- tion (MDC-NMF). In this paper, firstly, a new regularization term, called endmember distance (ED) is considered, which is defined as the sum of the squared Euclidean distances from each end- member to their geometric center. Compared with the simplex volume, ED has better optimization properties and is conceptually intuitive. Secondly, a projected gradient (PG) scheme is adopted, and by the virtue of ED, in this scheme the optimal step size along the feasible descent direction can be calculated easily at each iteration. Thirdly, a finite step ( no more than the number of endmem- bers) terminated algorithm is used to project a point on the canonical simplex, by which the abun- dance nonnegative constraint and abundance sum-to-one constraint can be accurately satisfied in a light amount of computation. The experimental results, based on a set of synthetic data and real da- ta, demonstrate that, in the same running time, MDC-NMF outperforms several other similar meth- ods proposed recently. 展开更多
关键词 hyperspectral data nonnegative matrix factorization (NMF) spectral unmixing convex function projected gradient (PG)
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A Framework of Convergence Analysis of Mini-batch Stochastic Projected Gradient Methods 被引量:1
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作者 Jian Gu Xian-Tao Xiao 《Journal of the Operations Research Society of China》 EI CSCD 2023年第2期347-369,共23页
In this paper,we establish a unified framework to study the almost sure global convergence and the expected convergencerates of a class ofmini-batch stochastic(projected)gradient(SG)methods,including two popular types... In this paper,we establish a unified framework to study the almost sure global convergence and the expected convergencerates of a class ofmini-batch stochastic(projected)gradient(SG)methods,including two popular types of SG:stepsize diminished SG and batch size increased SG.We also show that the standard variance uniformly bounded assumption,which is frequently used in the literature to investigate the convergence of SG,is actually not required when the gradient of the objective function is Lipschitz continuous.Finally,we show that our framework can also be used for analyzing the convergence of a mini-batch stochastic extragradient method for stochastic variational inequality. 展开更多
关键词 Stochastic projected gradient method Variance uniformly bounded Convergence analysis
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Projected gradient trust-region method for solving nonlinear systems with convex constraints
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作者 JIA Chun-xia ZHU De-tong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第1期57-69,共13页
In this paper, a projected gradient trust region algorithm for solving nonlinear equality systems with convex constraints is considered. The global convergence results are developed in a very general setting of comput... In this paper, a projected gradient trust region algorithm for solving nonlinear equality systems with convex constraints is considered. The global convergence results are developed in a very general setting of computing trial directions by this method combining with the line search technique. Close to the solution set this method is locally Q-superlinearly convergent under an error bound assumption which is much weaker than the standard nonsingularity condition. 展开更多
关键词 Nonlinear equation trust region method projected gradient local error bound.
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PROJECTED GRADIENT DESCENT BASED ON SOFT THRESHOLDING IN MATRIX COMPLETION 被引量:1
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作者 Zhao Yujuan Zheng Baoyu Chen Shouning 《Journal of Electronics(China)》 2013年第6期517-524,共8页
Matrix completion is the extension of compressed sensing.In compressed sensing,we solve the underdetermined equations using sparsity prior of the unknown signals.However,in matrix completion,we solve the underdetermin... Matrix completion is the extension of compressed sensing.In compressed sensing,we solve the underdetermined equations using sparsity prior of the unknown signals.However,in matrix completion,we solve the underdetermined equations based on sparsity prior in singular values set of the unknown matrix,which also calls low-rank prior of the unknown matrix.This paper firstly introduces basic concept of matrix completion,analyses the matrix suitably used in matrix completion,and shows that such matrix should satisfy two conditions:low rank and incoherence property.Then the paper provides three reconstruction algorithms commonly used in matrix completion:singular value thresholding algorithm,singular value projection,and atomic decomposition for minimum rank approximation,puts forward their shortcoming to know the rank of original matrix.The Projected Gradient Descent based on Soft Thresholding(STPGD),proposed in this paper predicts the rank of unknown matrix using soft thresholding,and iteratives based on projected gradient descent,thus it could estimate the rank of unknown matrix exactly with low computational complexity,this is verified by numerical experiments.We also analyze the convergence and computational complexity of the STPGD algorithm,point out this algorithm is guaranteed to converge,and analyse the number of iterations needed to reach reconstruction error.Compared the computational complexity of the STPGD algorithm to other algorithms,we draw the conclusion that the STPGD algorithm not only reduces the computational complexity,but also improves the precision of the reconstruction solution. 展开更多
关键词 Matrix Completion (MC) Compressed Sensing (CS) Iterative thresholding algorithm projected gradient Descent based on Soft Thresholding (STPGD)
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Application of a Derivative-Free Method with Projection Skill to Solve an Optimization Problem 被引量:1
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作者 PENG Fei SUN Guo-Dong 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第6期499-504,共6页
Improving numerical forecasting skill in the atmospheric and oceanic sciences by solving optimization problems is an important issue. One such method is to compute the conditional nonlinear optimal perturbation(CNOP),... Improving numerical forecasting skill in the atmospheric and oceanic sciences by solving optimization problems is an important issue. One such method is to compute the conditional nonlinear optimal perturbation(CNOP), which has been applied widely in predictability studies. In this study, the Differential Evolution(DE) algorithm, which is a derivative-free algorithm and has been applied to obtain CNOPs for exploring the uncertainty of terrestrial ecosystem processes, was employed to obtain the CNOPs for finite-dimensional optimization problems with ball constraint conditions using Burgers' equation. The aim was first to test if the CNOP calculated by the DE algorithm is similar to that computed by traditional optimization algorithms, such as the Spectral Projected Gradient(SPG2) algorithm. The second motive was to supply a possible route through which the CNOP approach can be applied in predictability studies in the atmospheric and oceanic sciences without obtaining a model adjoint system, or for optimization problems with non-differentiable cost functions. A projection skill was first explanted to the DE algorithm to calculate the CNOPs. To validate the algorithm, the SPG2 algorithm was also applied to obtain the CNOPs for the same optimization problems. The results showed that the CNOPs obtained by the DE algorithm were nearly the same as those obtained by the SPG2 algorithm in terms of their spatial distributions and nonlinear evolutions. The implication is that the DE algorithm could be employed to calculate the optimal values of optimization problems, especially for non-differentiable and nonlinear optimization problems associated with the atmospheric and oceanic sciences. 展开更多
关键词 differential evolution algorithm spectral projected gradient algorithm CNOP Burgers' equation optimization problem
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Exponentially convergent distributed Nash equilibrium seeking for constrained aggregative games 被引量:1
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作者 Shu Liang Peng Yi +1 位作者 Yiguang Hong Kaixiang Peng 《Autonomous Intelligent Systems》 2022年第1期71-78,共8页
Distributed Nash equilibrium seeking of aggregative games is investigated and a continuous-time algorithm is proposed.The algorithm is designed by virtue of projected gradient play dynamics and aggregation tracking dy... Distributed Nash equilibrium seeking of aggregative games is investigated and a continuous-time algorithm is proposed.The algorithm is designed by virtue of projected gradient play dynamics and aggregation tracking dynamics,and is applicable to games with constrained strategy sets and weight-balanced communication graphs.The key feature of our method is that the proposed projected dynamics achieves exponential convergence,whereas such convergence results are only obtained for non-projected dynamics in existing works on distributed optimization and equilibrium seeking.Numerical examples illustrate the effectiveness of our methods. 展开更多
关键词 Distributed algorithms Aggregative games projected gradient play Weight-balanced graph Exponential convergence
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A projected gradient based game theoretic approach for multi-user power control in cognitive radio network 被引量:1
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作者 Yun-zheng TAO Chun-yan WU +1 位作者 Yu-zhen HUANG Ping ZHANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2018年第3期367-378,共12页
The fifth generation (5G) networks have been envisioned to support the explosive growth of data demand caused by the increasing traditional high-rate mobile users and the expected rise of interconnections between hu... The fifth generation (5G) networks have been envisioned to support the explosive growth of data demand caused by the increasing traditional high-rate mobile users and the expected rise of interconnections between human and things. To accommodate the ever-growing data traffic with scarce spectrum resources, cognitive radio (CR) is considered a promising technology to improve spectrum utilization. We study the power control problem for secondary users in an underlay CR network. Unlike most existing studies which simplify the problem by considering only a single primary user or channel, we investigate a more realistic scenario where multiple primary users share multiple channels with secondary users. We formulate the power control problem as a non-cooperative game with coupled constraints, where the Pareto optimality and achievable total throughput can be obtained by a Nash equilibrium (NE) solution. To achieve NE of the game, we first propose a projected gradient based dynamic model whose equilibrium points are equivalent to the NE of the original game, and then derive a centralized algorithm to solve the problem. Simulation results show that the convergence and effectiveness of our proposed solution, emphasizing the proposed algorithm, are competitive. Moreover, we demonstrate the robustness of our proposed solution as the network size increases. 展开更多
关键词 Cognitive radio networks Multi-user power control Non-cooperative game Nash equilibrium projected gradient
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