We investigate in this paper the duality gap between quadratic knapsack problem and its Lagrangian dual or semidefinite programming relaxation. We characterize the duality gap by a distance measure from set {0, 1}<Superscript> n </Superscript> to certain polyhedral set and demonstrate that the duality gap can be reduced...</superscript>

This article describes how attractive structures are always correspond to objects of interest in human perception, thus extracting attractive structures is a fundamental problem in many image analysis tasks, which is of great practical importance. In this article, the authors propose a novel...