Stability of the intersection of solution sets of semi-infinite systems
β Scribed by Miguel A. Goberna; Mercedes Larriqueta; Virginia N. Vera de Serio
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 276 KB
- Volume
- 217
- Category
- Article
- ISSN
- 0377-0427
No coin nor oath required. For personal study only.
β¦ Synopsis
Many mathematical programming models arising in practice present a block structure in their constraint systems. Consequently, the feasibility of these problems depends on whether the intersection of the solution sets of each of those blocks is empty or not. The existence theorems allow to decide when the intersection of non-empty sets in the Euclidean space, which are the solution sets of systems of (possibly infinite) inequalities, is empty or not. In those situations where the data (i.e., the constraints) can be affected by some kind of perturbations, the problem consists of determining whether the relative position of the sets is preserved by sufficiently small perturbations or not. This paper focuses on the stability of the non-empty (empty) intersection of the solutions of some given systems, which can be seen as the images of set-valued mappings. We give sufficient conditions for the stability, and necessary ones as well; in particular we consider (semi-infinite) convex systems and also linear systems. In this last case we discuss the distance to ill-posedness.
π SIMILAR VOLUMES
A family of r sets is called a 2-system if any two sets have the same intersection. Denote by F(n, r) the most number of subsets of an n-element set which do not contain a 2-system consisting of r sets. Constructive new lower bounds for F(n, r) are given which improve known probabilistic results, an
Erdos and Rado defined a A-system, as a family in which every two members have the same intersection. Here we obtain a new upper bound on the maximum cardinality q ( n , q ) of an n-uniform family not containing any A-system of cardinality q. Namely, we prove that, for any a > 1 and q , there exists