This paper introduces two new techniques for solving the Quadratic Assignment Problem. The first is a heuristic technique, defined in accordance to the Ant System metaphor, and includes as a distinctive feature the use of a new lower bound at each constructive step. The second is a branch and bound exact approach, containing some elements introduced in the Ant algorithm. Computational results p...

We investigate the stochastic flow shop problem with m machines and general distributions for processing times. No analytic method exists for solving this problem, so we looked instead at heuristic methods. We devised three constructive procedures with modest computational requirements, each based on approaches that have been successful at solving the deterministic counterpart. We compared the ...

The blocking flow-shop scheduling problem, which is an NP-hard has wide applications in industry. Many studies have focused primarily on single-objective optimization, such as minimizing the makespan or total flow time, insufficient for practical problems. In this study, a problem with bicriteria of and machine utilization considered. A simple constructive heuristic, NEHCG, proposed by developi...

The literature review shows software development projects often neither meet time deadlines, nor run within the allocated budgets. One common reason can be the inaccurate cost estimation process, although several approaches have been proposed in this field. Recent research studies suggest that in order to increase the accuracy of this process, estimation models have to be revised. The Construct...

Pixel advertising represents the placement of multiple pixel blocks on a banner for the purpose of advertising companies and their products. In this paper, we investigate how one can avoid product conflicts in the placement of pixel advertisements on a Web banner, while maximizing the overall banner revenue. Our solution for this problem is based on a product ontology that defines products and ...

This paper presents an algorithm for inducing recursive rst order Horn clause programs from examples without background knowledge. This algorithm invents new predicates and their de nitions exhaustively until the instances of a new predicate become the same as examples except for the name of the predicate. Our system CIRP switches into constructive induction mode using a new heuristic taking ad...

This paper proposes an efficient heuristic algorithm for solving a complex batching and scheduling problem in a diffusion area of a semiconductor plant. Diffusion is frequently bottleneck in the plant and also one of the most complex areas in terms of number of machines, constraints to satisfy and the large number of lots to manage. The purpose of this study is to investigate an approach to gro...

This work presents a new constructive heuristic for graph coloring based on Genetic Algorithms. The Constructive Genetic Algorithm (CGA) begins with an initial population formed only of schemas (partial colorings), and iterates (re)combining two schemas. The new schemas present more colored nodes. At each iteration, is performed an elimination of schemas from the population and the process fini...

This paper discusses the problem of placing weighted items in a circular container in two-dimensional space. This problem is of great practical significance in various mechanical engineering domains, such as the design of communication satellites. Two constructive heuristics are proposed, one for packing circular items and the other for packing rectangular items. These work by first optimizing ...

The majority of the scheduling studies carry a common assumption that machines are available all the time. However, machines may not always be available in the scheduling period due to breakdown or preventive maintenance. Taking preventive maintenance activity into consideration, we dealt with the twomachine flowshop scheduling problem with makespan objective. The preventive maintenance policy ...