非负拉格朗日松弛优化的子空间聚类算法  

Subspace clustering algorithm optimized by non-negative Lagrangian relaxation

作　　者：朱东霞 贾洪杰 黄龙霞 ZHU Dongxia;JIA Hongjie;HUANG Longxia(School of Computer Science and Communication Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学计算机科学与通信工程学院,江苏镇江212013

出　　处：《西安电子科技大学学报》2024年第1期100-113,共14页Journal of Xidian University

基　　金：国家自然科学青年基金(61906077,62102168);江苏省自然科学青年基金(BK20190838,BK20200888);中国博士后科学基金(2020T130257,2020M671376);江苏省博士后科学基金(2021K596C)。

摘　　要：传统的子空间聚类和谱聚类中普遍使用谱松弛方法聚类,需要先计算拉普拉斯矩阵的特征向量。特征向量中包含负数,根据元素的正负可以直接得到二类聚类的结果。对于多类聚类问题,需要递归地进行二划分,或在特征向量空间中使用k-means算法聚类,分配类簇标签是间接的,这种后处理的聚类方式会增加聚类结果的不稳定性。针对谱松弛的问题,提出了一种非负拉格朗日松弛优化的子空间聚类算法,在目标函数中集成了自表示学习和秩约束。通过非负拉格朗日松弛来求解相似性矩阵和隶属矩阵,并保持隶属矩阵的非负性。在这种情况下,原来的隶属矩阵就变成了类簇的后验概率,当算法收敛时,只需将数据点分配给具有最大后验概率的类簇,即可得到聚类结果。与已有的子空间聚类和谱聚类方法相比,所提出的算法设计了新的优化规则,可以实现类簇标签的直接分配,不需要额外的聚类步骤。最后,给出了算法的收敛性证明。在5个基准聚类数据集上的大量实验表明,所提算法的聚类性能优于近几年来的子空间聚类方法。Spectral relaxation is widely used in traditional subspace clustering and spectral clustering.First,the eigenvector of the Laplacian matrix is calculated.The eigenvector contains negative numbers,and the result of the 2-way clustering can be obtained directly according to the positive and negative of the elements.For multi-way clustering problems,2-way graph partition is applied recursively or the k-means is used in eigenvector space.The assignment of the cluster label is indirect.The instability of clustering results will increase by this post-processing clustering method.For the limitation of spectral relaxation,a subspace clustering algorithm optimized by non-negative Lagrangian relaxation is proposed,which integrates self-representation learning and rank constraints in the objective function.The similarity matrix and membership matrix are solved by non-negative Lagrangian relaxation and the nonnegativity of the membership matrix is maintained.In this way,the membership matrix becomes the cluster posterior probability.When the algorithm converges,the clustering results can be obtained directly by assigning the data object to the cluster with the largest posterior probability.Compared with the existing subspace clustering and spectral clustering methods,the proposed algorithm designs a new optimization rule,which can realize the direct allocation of cluster labels without additional clustering steps.Finally,the convergence of the proposed algorithm is analyzed theoretically.Generous experiments on five benchmark clustering datasets show that the clustering performance of the proposed method is better than that of the recent subspace clustering methods.

关 键 词：聚类算法 自表示 优化 非负拉格朗日松弛 子空间聚类 

分 类 号：TN96[电子电信—信号与信息处理]