Skip Navigation

IEICE Transactions on Information and Systems 2008 E91-D(12):2776-2783; doi:10.1093/ietisy/e91-d.12.2776
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by UENO, K.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 2008 The Institute of Electronics, Information and Communication Engineers

Regular Section -- Papers -- Complexity Theory

Relating L versus P to Reversal versus Access and Their Combinatorial Structures

Kenya UENO1

1 The author is with the Department of Computer Science, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, 113–8656 Japan. E-mail: kenya{at}is.s.u-tokyo.ac.jp


  Abstract

Reversal complexity has been studied as a fundamental computational resource along with time and space complexity. We revisit it by contrasting with access complexity which we introduce in this study. First, we study the structure of space bounded reversal and access complexity classes. We characterize the complexity classes L, P and PSPACE in terms of space bounded reversal and access complexity classes. We also show that the difference between polynomial space bounded reversal and access complexity is related with the L versus P problem. Moreover, we introduce a theory of memory access patterns, which is an abstracted structure of the order of memory accesses during a random access computation, and extend the notion of reversal and access complexity for general random access computational models. Then, we give probabilistic analyses of reversal and access complexity for almost all memory access patterns. In particular, we prove that almost all memory access patterns have {omega}(log n) reversal complexity while all languages in L are computable within O(log n) reversal complexity.

Key Words: complexity classes, random combinatorial structures

Manuscript received July 31, 2008.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.