Quasi-concave functions and convex convergence to infinity

Some Properties of Certain Subclasses of Close-to-Convex and Quasi-convex Functions with Respect to 2k-Symmetric Conjugate Points

Quasi-concave functions on antimatroids

In this paper we consider quasi-concave set functions defined on antimatroids. There are many equivalent axiomatizations of antimatroids, that may be separated into two categories: antimatroids defined as set systems and antimatroids defined as languages. An algorthmic characterization of antimatroids, that considers them as set systems, was given in [4]. This characterization is based on the i...

On Convergence Rate of Concave-Convex Procedure

Concave-Convex Procedure (CCCP) has been widely used to solve nonconvex d.c.(difference of convex function) programs occur in learning problems, such as sparse support vector machine (SVM), transductive SVM, sparse principal componenent analysis (PCA), etc. Although the global convergence behavior of CCCP has been well studied, the convergence rate of CCCP is still an open problem. Most of d.c....

Quasi-Concave Functions and Greedy Algorithms

Many combinatorial optimization problems can be formulated as: for a given set system over E (i.e., for a pair (E, ) where ⊆ 2E is a family of feasible subsets of finite set E), and for a given function F : →R, find an element of for which the value of the function F is minimum or maximum. In general, this optimization problem is NP-hard, but for some specific functions and set systems the prob...

Convex and concave relaxations of implicit functions