We present a proof procedure that combines backward reasoning with logic programs and forward reasoning with integrity constraints. We illustrate the use of the proof procedure as the inference engine underlying agents. Roughly speaking, the backward reasoning component of the proof procedure is responsible for the deliberative behaviour of agents, whereas the forward reasoning component is res...

The requirements analysis of critical software components often involves a search for hazardous states and failure modes. This paper describes the integration of a forward search for consequences of reaching these forbidden modes with a backward search for contributing causes. Results are reported from two projects in which the integrated search method was used to analyze the requirements of cr...

We describe a hybrid meta-heuristic algorithm for combinatorial optimization problems with a specific reference to the travelling salesman problem (TSP). The method is a combination of a genetic algorithm (GA) and greedy randomized adaptive search procedure (GRASP). A new adaptive fuzzy a greedy search operator is developed for this hybrid method. Computational experiments using a wide range of...

The determination of the spatial distributions that atoms adopt to form condensed matter is a problem of crucial importance, since most physical properties depend on the atomic arrangement. This is especially relevant for clusters, where periodicity is nonexistent. Several optimization procedures have been implemented to tackle this problem, with ever increasing success. Here we put forward a s...

In this paper, a new hybrid metaheuristic algorithm based on the scatter search approach is developed to solve the well-known resource-constrained project scheduling problem. This algorithm combines two solutions from scatter search to build a set of precedence feasible activity lists and select some of them as children for the new population. We use the idea presented in the iN forward/backwar...