A* Search with Inconsistent Heuristics
نویسندگان
چکیده
Early research in heuristic search discovered that using inconsistent heuristics with A* could result in an exponential increase in the number of node expansions. As a result, the use of inconsistent heuristics has largely disappeared from practice. Recently, inconsistent heuristics have been shown to be effective in IDA*, especially when applying the bidirectional pathmax (BPMX) enhancement. This paper presents new worst-case complexity analysis of A*’s behavior with inconsistent heuristics, discusses how BPMX can be used with A*, and gives experimental results justifying the use of inconsistent heuristics in A* searches.
منابع مشابه
Using Inconsistent Heuristics on A∗ Search
Early research in heuristic search discovered that using inconsistent heuristics in an A∗ search could result in an exponential blow-up in the number of nodes expanded. As a result, the use of inconsistent heuristics has largely disappeared from practice. However, recent research has shown that they can yield dramatic performance improvements to an IDA∗ search using the BPMX enhancement. This p...
متن کاملInconsistent heuristics in theory and practice
In the field of heuristic search it is usually assumed that admissible heuristics are consistent, implying that consistency is a desirable attribute. The term “inconsistent heuristic” has, at times, been portrayed negatively, as something to be avoided. Part of this is historical: early research discovered that inconsistency can lead to poor performance for A* (nodes might be re-expanded many t...
متن کاملInconsistency and Accuracy of Heuristics with A* Search
Many studies in heuristic search suggest that the accuracy of the heuristic used has a positive impact on improving the performance of the search. In another direction, historical research perceives that the performance of heuristic search algorithms, such as A* and IDA*, can be improved by requiring the heuristics to be consistent – a property satisfied by any perfect heuristic. However, a few...
متن کاملA discrete particle swarm optimization algorithm with local search for a production-based two-echelon single-vendor multiple-buyer supply chain
This paper formulates a two-echelon single-producer multi-buyer supply chain model, while a single product is produced and transported to the buyers by the producer. The producer and the buyers apply vendor-managed inventory mode of operation. It is assumed that the producer applies economic production quantity policy, which implies a constant production rate at the producer. The operational pa...
متن کاملInconsistent Heuristics
In the field of heuristic search it is well-known that improving the quality of an admissible heuristic can significantly decrease the search effort required to find an optimal solution. Existing literature often assumes that admissible heuristics are consistent, implying that consistency is a desirable attribute. To the contrary, this paper shows that an inconsistent heuristic can be preferabl...
متن کامل