Titlebook: Integer Programming and Combinatorial Optimization; 19th International C Friedrich Eisenbrand,Jochen Koenemann Conference proceedings 2017

ITCH

Integrality Gaps of Integer Knapsack Problems,We obtain optimal lower and upper bounds for the (additive) integrality gaps of integer knapsack problems. In a randomised setting, we show that the integrality gap of a “typical” knapsack problem is drastically smaller than the integrality gap that occurs in a worst case scenario.

hauteur

978-3-319-59249-7Springer International Publishing AG 2017

打折

甜瓜

https://doi.org/10.1007/978-3-319-59250-3Approximation theory; Combinatorial optimization; Computational results; Integer programming; Linear pro

Fallibility

,An Improved Integrality Gap for the C?linescu-Karloff-Rabani Relaxation for Multiway Cut,tance has an integrality ratio of ., for every constant .. For every ., this improves upon a long-standing lower bound of . by Freund and Karloff?[.]. Due to the result by Manokaran et al.?[.], our integrality gap also implies Unique Games hardness of approximating Multiway Cut of the same ratio.

Impugn

burnish

On Scheduling Coflows,-approximation and a randomized .-approximation algorithm. In this paper, we give a combinatorial algorithm that yields a deterministic 5-approximation algorithm with release times, and a deterministic 4-approximation for the case without release time.

Arteriography

MOAN

Mixed-Integer Linear Representability, Disjunctions, and Variable Elimination,vered by the Williams-Hooker scheme. Second, disjunctions of Chvátal systems can give sets that are . projections of mixed-integer linear sets; so the Williams-Hooker approach does not give an exact characterization of MILP representability.

ERUPT

Deterministic Fully Dynamic Approximate Vertex Cover and Fractional Matching in ,(1) Amortized Updaf .. Our result can be generalized to give a fully dynamic .-approximation algorithm with . amortized update time for the hypergraph vertex cover and fractional matching problems, where every hyperedge has at most . vertices.