We introduce a new framework of restricted 2-matchings close to Hamilton cycles. For an undirected graph (V,E) and a family U of vertex subsets, a 2-matching F is called U-feasible if, for each U ∈ U , F contains at most |U | − 1 edges in the subgraph induced by U . Our framework includes C≤k-free 2-matchings, i.e., 2-matchings without cycles of at most k edges, and 2-factors covering prescribe...

We tackle the thief orienteering problem (ThOP), an academic multi-component that combines two classical combinatorial problems, namely Knapsack Problem and Orienteering Problem. In ThOP, a has time limit to steal items distributed in given set of cities. While traveling, collects by storing them their knapsack, which turn reduces travel speed. The as objective maximize total profit stolen item...

Models so far considered as facility location problems treat either min–max or max–min criterion, that is, the facility is either desirable or undesirable. We propose the following model considering the satisfaction degree with respect to the distance from the facility for each customer (residents) and preference of the site in an urban area. The objective is to find the site of the facility wh...

This paper considers the task of learning a binary labeling of the vertices of a graph, given only a small set of positive examples and knowledge of the desired amount of positives. A learning machine is described maximizing the precision of the prediction, a combinatorial optimization problem which can be rephrased as a S-T mincut problem. For validation, we consider the movie recommendation d...

Max-3-SAT. In this problem, the domain is {0, 1}; a collection of constraint types are disjunctions of the form {xi∨xj ∨xk, xi∨xj ∨xk, xi∨xj ∨xk, . . . , xi∨xj ∨xk, xi∨xj, . . . , xi∨ xj, xi, xi} resulting in total of 14 constraint types. Max-Cut. Here, the domain is again {0, 1}, the collection of constraint types is simply {vi 6= vj}. Intuitively, we have one such constraint for each edge in ...

in biological wastewater treatment large quantities of sludge are produced. this sludge is highly putrescible.for disposal and safe usage should be stabilized. the anaerobic digestion is a standard technique for stabilization. due to the rate imiting step of sludge hydrolysis, anaerobic degradation is a slow process with high digestion time. due to high retention time and sludge dewatering prob...

We study the resolution complexity of Tseitin formulas over arbitrary rings in terms of combinatorial properties of graphs. We give some evidence that the expansion of a graph is a good characterization of the resolution complexity of Tseitin formulas. We extend the method of Ben-Sasson and Wigderson of proving lower bound on the size of resolution proofs to the constraint satisfaction problem ...

Seymour proved that the set of odd circuits of a signed binary matroid (M; ) has the Max-Flow Min-Cut property if and only if it does not contain a minor isomorphic to (M(K4); E(K4)). We give a shorter proof of this result.