论文标题
基于列分区的分布式算法用于耦合凸稀疏优化:双重和精确的正则化方法
Column Partition based Distributed Algorithms for Coupled Convex Sparse Optimization: Dual and Exact Regularization Approaches
论文作者
论文摘要
本文开发了基于列分区的分布式方案,用于一类大规模凸稀疏优化问题,例如基础追求(BP),lasso,基本追求表示(BPDN)及其扩展,例如融合lasso。我们对(标量)决策变量的数量远大于(标量)测量值的数量特别感兴趣,并且每个代理的内存或计算能力有限,因此仅知道少数测量矩阵的列。考虑的这些问题密集耦合,不能使用列分区作为可分离的凸面程序进行配合。为了克服这一困难,我们认为它们的双重问题是可分离或局部耦合的。一旦达到双重溶液,就表明在适当的正则化条件下,可以从相应的正规化BP样问题的双重溶液中找到原始溶液。可以利用各种现有的分布式方案来解决获得的双重问题。这产生了基于两阶段分区的分布方案,用于类似于套索和BPDN的问题。这些方案的总体收敛是使用灵敏度分析技术建立的。数值结果说明了提出的方案的有效性。
This paper develops column partition based distributed schemes for a class of large-scale convex sparse optimization problems, e.g., basis pursuit (BP), LASSO, basis pursuit denosing (BPDN), and their extensions, e.g., fused LASSO. We are particularly interested in the cases where the number of (scalar) decision variables is much larger than the number of (scalar) measurements, and each agent has limited memory or computing capacity such that it only knows a small number of columns of a measurement matrix. These problems in consideration are densely coupled and cannot be formulated as separable convex programs using column partition. To overcome this difficulty, we consider their dual problems which are separable or locally coupled. Once a dual solution is attained, it is shown that a primal solution can be found from the dual of corresponding regularized BP-like problems under suitable exact regularization conditions. A wide range of existing distributed schemes can be exploited to solve the obtained dual problems. This yields two-stage column partition based distributed schemes for LASSO-like and BPDN-like problems; the overall convergence of these schemes is established using sensitivity analysis techniques. Numerical results illustrate the effectiveness of the proposed schemes.