This note confirms a conjecture of (Bramoullé in Games Econ Behav 58:30–49, 2007). The problem, which we name the maximum independent cut problem, is a restricted version of the MAX-CUT problem, requiring one side of the cut to be an independent set. We show that the maximum independent cut problem does not admit any polynomial time algorithm with approximation ratio better than n1− , where n i...

Generalizing the cost in the standard min-cut problem to a submodular cost function immediately makes the problem harder. Not only do we prove NP hardness even for nonnegative submodular costs, but also show a lower bound of Ω(|V |) on the approximation factor for the (s, t) cut version of the problem. On the positive side, we propose and compare three approximation algorithms with an overall a...

This paper describes certain facet classes for the planar subgraph polytope. These facets are extensions of Kuratowski facets and are of the form 2x(U)+x(E(G)\U) ≤ 2|U |+|E(G)\U | −2 where the edge set U varies and can be empty. Two of the new types of facets complete the class of extended subdivision facets, explored by Jünger and Mutzel. In addition, the other types of facets consist of a new...

A subset S of V (G) is an independent dominating set of G if S is independent and each vertex of G is either in S or adjacent to some vertex of S. Let i(G) denote the minimum cardinality of an independent dominating set of G. A graph G is k-i-critical if i(G) = k, but i(G+uv) < k for any pair of non-adjacent vertices u and v of G. In this paper, we establish that if G is a connected 3-i-critica...

The aim of this paper is to develop an effective method for solving matrix games with payoffs of triangular fuzzy numbers (TFNs) which are arbitrary. In this method, it always assures that players’ gain-floor and loss-ceiling have a common TFN-type fuzzy value and hereby any matrix game with payoffs of TFNs has a TFN-type fuzzy value. Based on duality theorem of linear programming (LP) and the ...

We consider the application of mixed-integer linear programming (MILP) solvers to the minimization of submodular functions. We evaluate common large-scale linear-programming (LP) techniques (e.g., column generation, row generation, dual stabilization) for solving a LP reformulation of the submodular minimization (SM) problem. We present heuristics based on the LP framework and a MILP solver. We...

This paper describes an image based clothes detection method. Our method enables daily assistive robots to find clothes which are readily placed on real environments. No prior knowledge related to shape model or color information is needed because wrinkles on a cloth are extracted as image feature. The feature is constructed through SVM learning by using training data which is the result of Gab...

In the double TSP with multiple stacks, a vehicle with several stacks performs a Hamiltonian circuit to pick up some items and stores them in its stacks. It then delivers every item by performing another Hamiltonian circuit while satisfying the last-in-first-out policy of its stacks. The consistency requirement ensuring that the pickup and delivery circuits can be performed by the vehicle is th...

Let (L;⊓,⊔) be a finite lattice and let n be a positive integer. A function f : L → R is said to be submodular if f(a ⊓ b) + f(a ⊔ b) ≤ f(a)+f(b) for all a, b ∈ L. In this paper we study submodular functions when L is a diamond. Given oracle access to f we are interested in finding x ∈ L such that f(x) = miny∈Ln f(y) as efficiently as possible. We establish • a min–max theorem, which states tha...

Symmetri Generalized Travelling Salesman Problem Matteo Fis hetti Juan Jos e Salazar Gonz alezy Paolo Tothz January 1994; Revised May 1995 Abstra t We onsider a variant of the lassi al symmetri Travelling Salesman Problem in whi h the nodes are partitioned into lusters and the salesman has to visit at least one node for ea h luster. This NP-hard problem is known in the literature as the symmetr...