In this paper, we are interested in the Maximum Satisfiability Problem (MAX-SAT) which is an optimization variant of the Boolean satisfiability problem (SAT). SAT is of a central importance in various areas of computer science, including theoretical computer science, algorithmic, artificial intelligence, hardware design and verification. Formally, given a set of m clauses C = {C1;C2 . . . Cm} i...

In this paper we propose a hybrid approach for solving vehicle routing problems. The main idea is to combine an Ant System (AS) with a problem specific constructive heuristic, namely the well known Savings algorithm. This differs from previous approaches, where the subordinate heuristic was the Nearest Neighbor algorithm initially proposed for the TSP. We compare our approach with some other cl...

In this paper, we consider joint scheduling of jobs and preventive maintenance operations on a single machine with an objective to minimize the total earliness and tardiness of jobs about a common due date. The properties of an optimal schedule are identified and utilized to develop a constructive heuristic and a lower bound estimate. The properties are also utilized to hybridize Tabu search a...

The transmission expansion planning problem in modern power systems is a large-scale, mixed-integer, non-linear and non-convex problem. This paper presents a novel mathematical model to solve security constraints transmission system expansion planning problem via a constructive heuristic algorithm (CHA). The basic idea comes from Garver’s work applied to the transportation model; nevertheless t...

The Coors warehouse scheduling problem involves nding a permutation of customer orders that minimizes the average time that customers' orders spend at the loading docks while at the same time minimizing the running average inventory. Search based solutions require fast objective functions. Thus, a fast low-resolution simulation is used as an objective function. A slower high-resolution simulati...

Optimization in sports is a field of increasing interest. A novel problem in sports management is the Referee Assignment Problem, in which a limited number of referees with different qualifications and availabilities should be assigned to a set of games already scheduled. We extend and improve a previous three-phase approach for this problem, based on a constructive heuristic, a repair heuristi...

Dynamic lotsizing and scheduling on multiple lines to meet the customer due dates is significant in multi-line production environments. Therefore, this study investigates dynamic problems flexible machining considering mixed products. In addition, uncertainty demand machine failure considered. A mathematical model proposed for considered problem with an aim maximize probability of completion pr...

In this paper, we propose an iterated greedy algorithm for solving the blocking flow shop scheduling problem with total flow time minimization objective. The steps of this algorithm are designed very efficient. For generating an initial solution, we develop an efficient constructive heuristic by modifying the best known NEH algorithm. Effectiveness of the proposed iterated greedy algorithm is t...

This article concerns a problem still seldom studied, the two-echelon or two-level vehicle routing problem (LRP-2E). It is raised by distribution or collection networks involving two sets of vehicle trips: first-level trips serve from a main depot a set of satellite depots, which must be located, while second-level trips visit customers from these satellites. After a literature review on the LR...