Abstract. In this paper, the experiments with local search heuristic algorithms for the traveling salesman problem (TSP) are described. Since the ordinary local search heuristics very seldom yield solutions of high quality, we investigate the enhanced local search algorithms using the extended neighbourhood structures. We also examine the performance of the local search heuristics in an iterate...

Ordered Binary Decision Diagrams (OBDDs) are the state-of-the-art data structure in CAD for ICs. OBDDs are very sensitive to the chosen variable ordering, i.e. the size may vary from linear to exponential. In this paper we present an Evolutionary Algorithm (EA) that learns good heuristics for OBDD minimization starting from a given set of basic operations. The diierence to other previous approa...

This paper studies the practical impact of the branching heuristics used in Propositional Satisfiability (SAT) algorithms, when applied to solving real-world instances of SAT. In addition, different SAT algorithms are experimentally evaluated. The main conclusion of this study is that even though branching heuristics are crucial for solving SAT, other aspects of the organization of SAT algorith...

This study presents shape optimization of a gravity dam imposing stability and principal stress constraints. A gravity dam is a large scale hydraulic structure consisting of huge amount of concrete material. Hence, an optimum design gives a cost-benefit structure due to the fact that small changes in shape of dam cross-section leads to large saving of concrete volume. T...

Hyper-heuristics are (meta-)heuristics that operate at a high level to choose or generate a set of low-level (meta-)heuristics to solve difficult search and optimisation problems. Evolutionary algorithms are well-known natureinspired meta-heuristics that simulate Darwinian evolution. In this article, we introduce an evolutionary-based hyper-heuristic in which a set of low-level heuristics compe...

Nowadays, cross-docking is one of the main concepts in supply chain management in which products received to a distribution center by inbound trucks which are directly to lead into outbound trucks with a minimum handling and storage costs as the main cost of a cross-docking system. According to the literature, several metaheuristics and heuristics are attempted to solve this optimization model....

We study the existence of time hierarchies for heuristic algorithms. We prove that a time hierarchy exists for heuristics algorithms in such syntactic classes as NP and coNP, and also in semantic classes AM and MA. Earlier, Fortnow and Santhanam (FOCS’04) proved the existence of a time hierarchy for heuristics algorithms in BPP. We present an alternative approach and give a simpler proof.

Many planning tasks of autonomous robots can be modeled as partially observable Markov decision process (POMDP) problems. Point-based algorithms are well-known algorithms for solving large-scale POMDP problems. Several leading point-based algorithms eschew some flawed but very useful heuristics to find an -optimal policy. This paper aims at exploiting these avoided heuristics by a simple framew...