期刊名称:CORE Discussion Papers / Center for Operations Research and Econometrics (UCL), Louvain
出版年度:2007
卷号:1
出版社:Center for Operations Research and Econometrics (UCL), Louvain
摘要:In this paper we analyze several new methods for solving optimization problems with
the objective function formed as a sum of two convex terms: one is smooth and given
by a black-box oracle, and another is general but simple and its structure is known.
Despite to the bad properties of the sum, such problems, both in convex and
nonconvex cases, can be solved with efficiency typical for the good part of the
objective. For convex problems of the above structure, we consider primal and dual
variants of the gradient method (converge as O(1/k)), and an accelerated multistep
version with convergence rate O(1/k2), where k is the iteration counter. For all
methods, we suggest some efficient "line search" procedures and show that the
additional computational work necessary for estimating the unknown problem class
parameters can only multiply the complexity of each iteration by a small constant
factor. We present also the results of preliminary computational experiments, which
confirm the superiority of the accelerated scheme.