The minimal set of states that must be expanded in a front-to-end bidirectional search

Eshed Shaham; Jingwei Chen; Ariel Felner; Nathan R. Sturtevant

The minimal set of states that must be expanded in a front-to-end bidirectional search

Eshed Shaham
, Jingwei Chen
, Ariel Felner
, Nathan R. Sturtevant

Research output: Contribution to conference › Paper › peer-review

31 Scopus citations

Abstract

A* is optimal among admissible unidirectional algorithms when searching with a consistent heuristic. Recently, similar optimality bounds have been established for bidirectional search but, no practical algorithm is guaranteed to always achieve this bound. In this paper we study the nature of the number of nodes that must be expanded in any front-to-end bidirectional search. We present an efficient algorithm for computing that number and show that a theoretical parameterized generalization of MM, with the correct parameter, is the optimal front-to-end bidirectional search. We then experimentally compare various algorithms and show how far they are from optimal.

Original language	English
Pages	82-90
Number of pages	9
State	Published - 1 Jan 2017
Event	10th Annual Symposium on Combinatorial Search, SoCS 2017 - Pittsburgh, United States Duration: 16 Jun 2017 → 17 Jun 2017

Conference

Conference	10th Annual Symposium on Combinatorial Search, SoCS 2017
Country/Territory	United States
City	Pittsburgh
Period	16/06/17 → 17/06/17

ASJC Scopus subject areas

Computer Networks and Communications

Cite this

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title = "The minimal set of states that must be expanded in a front-to-end bidirectional search",

abstract = "A* is optimal among admissible unidirectional algorithms when searching with a consistent heuristic. Recently, similar optimality bounds have been established for bidirectional search but, no practical algorithm is guaranteed to always achieve this bound. In this paper we study the nature of the number of nodes that must be expanded in any front-to-end bidirectional search. We present an efficient algorithm for computing that number and show that a theoretical parameterized generalization of MM, with the correct parameter, is the optimal front-to-end bidirectional search. We then experimentally compare various algorithms and show how far they are from optimal.",

author = "Eshed Shaham and Jingwei Chen and Ariel Felner and Sturtevant, \{Nathan R.\}",

note = "Publisher Copyright: Copyright c 2017, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved.; 10th Annual Symposium on Combinatorial Search, SoCS 2017 ; Conference date: 16-06-2017 Through 17-06-2017",

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AU - Felner, Ariel

AU - Sturtevant, Nathan R.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - A* is optimal among admissible unidirectional algorithms when searching with a consistent heuristic. Recently, similar optimality bounds have been established for bidirectional search but, no practical algorithm is guaranteed to always achieve this bound. In this paper we study the nature of the number of nodes that must be expanded in any front-to-end bidirectional search. We present an efficient algorithm for computing that number and show that a theoretical parameterized generalization of MM, with the correct parameter, is the optimal front-to-end bidirectional search. We then experimentally compare various algorithms and show how far they are from optimal.

AB - A* is optimal among admissible unidirectional algorithms when searching with a consistent heuristic. Recently, similar optimality bounds have been established for bidirectional search but, no practical algorithm is guaranteed to always achieve this bound. In this paper we study the nature of the number of nodes that must be expanded in any front-to-end bidirectional search. We present an efficient algorithm for computing that number and show that a theoretical parameterized generalization of MM, with the correct parameter, is the optimal front-to-end bidirectional search. We then experimentally compare various algorithms and show how far they are from optimal.

UR - https://www.scopus.com/pages/publications/85050544330

M3 - Paper

AN - SCOPUS:85050544330

SP - 82

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T2 - 10th Annual Symposium on Combinatorial Search, SoCS 2017

Y2 - 16 June 2017 through 17 June 2017

ER -

The minimal set of states that must be expanded in a front-to-end bidirectional search

Abstract

Conference

ASJC Scopus subject areas

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