Author image not provided
 Raghunath Tewari

Authors:
Add personal information
  Affiliation history
Bibliometrics: publication history
Average citations per article2.60
Citation Count26
Publication count10
Publication years2007-2017
Available for download3
Average downloads per article226.33
Downloads (cumulative)679
Downloads (12 Months)89
Downloads (6 Weeks)3
SEARCH
ROLE
Arrow RightAuthor only


AUTHOR'S COLLEAGUES
See all colleagues of this author

SUBJECT AREAS
See all subject areas




BOOKMARK & SHARE


10 results found Export Results: bibtexendnoteacmrefcsv

Result 1 – 10 of 10
Sort by:

1 published by ACM
December 2017 ACM Transactions on Computation Theory (TOCT): Volume 9 Issue 4, January 2018
Publisher: ACM
Bibliometrics:
Citation Count: 0
Downloads (6 Weeks): 2,   Downloads (12 Months): 56,   Downloads (Overall): 56

Full text available: PDFPDF
Given a graph G and two vertices s and t in it, graph reachability is the problem of checking whether there exists a path from s to t in G . We show that reachability in directed layered planar graphs can be decided in polynomial time and O ( n ...
Keywords: Directed reachability problem, layered grid graph, layered planar graph, time-space tradeoff

2 published by ACM
March 2014 ACM SIGACT News: Volume 45 Issue 1, March 2014
Publisher: ACM
Bibliometrics:
Citation Count: 0
Downloads (6 Weeks): 0,   Downloads (12 Months): 10,   Downloads (Overall): 64

Full text available: PDFPDF

3
March 2014 Computational Complexity: Volume 23 Issue 1, March 2014
Publisher: Birkhauser Verlag
Bibliometrics:
Citation Count: 0

We show that two complexity classes introduced about two decades ago are unconditionally equal. ReachUL is the class of problems decided by nondeterministic log-space machines which on every input have at most one computation path from the start configuration to any other configuration. ReachFewL, a natural generalization of ReachUL, is ...
Keywords: 68Q05, 68Q10, unambiguous computations, 68Q15, 68Q17, Log-space complexity, graph reachability

4
June 2012 Information and Computation: Volume 215, June, 2012
Publisher: Academic Press, Inc.
Bibliometrics:
Citation Count: 2

We show a simple application of [email protected]?s theorem from multivariable calculus to the isolation problem in planar graphs. In particular, we give a log-space construction of a skew-symmetric, polynomially-bounded edge weight function for directed planar graphs, such that the weight of any simple cycle in the graph is non-zero with ...
Keywords: Green's theorem, Isolating lemma, Space complexity

5
May 2012 Journal of Computer and System Sciences: Volume 78 Issue 3, May, 2012
Publisher: Academic Press, Inc.
Bibliometrics:
Citation Count: 1

We investigate the space complexity of certain perfect matching problems over bipartite graphs embedded on surfaces of constant genus (orientable or non-orientable). We show that the problems of deciding whether such graphs have (1) a perfect matching or not and (2) a unique perfect matching or not, are in the ...
Keywords: Perfect matching, Space complexity, Topological graph theory

6
August 2011 COCOON'11: Proceedings of the 17th annual international conference on Computing and combinatorics
Publisher: Springer-Verlag
Bibliometrics:
Citation Count: 0

We show that two complexity classes introduced about two decades ago are equal. ReachUL is the class of problems decided by nondeterministic log-space machines which on every input have at most one computation path from the start configuration to any other configuration. ReachFewL, a natural generalization of ReachUL, is the ...

7
January 2011
Bibliometrics:
Citation Count: 0

Space complexity investigates the power and limitations of a computational model (e.g. a Turing machine) which has a limited amount of workspace to perform its computation. Particularly interesting is the case when the space is only logarithmic in the input size. Unambiguous computation is a natural restriction of ...

8
December 2009 ANTS'09: Proceedings of the 3rd international conference on Advanced networks and telecommunication systems
Publisher: IEEE Press
Bibliometrics:
Citation Count: 0

Protecting a network against link failures is a major challenge faced by network operators. The protection scheme has to address two important objectives - fast recovery and minimizing the amount of backup resources needed. Every protection algorithm is a tradeoff between these two objectives. In this paper, we study the ...

9 published by ACM
February 2009 ACM Transactions on Computation Theory (TOCT): Volume 1 Issue 1, February 2009
Publisher: ACM
Bibliometrics:
Citation Count: 11
Downloads (6 Weeks): 3,   Downloads (12 Months): 16,   Downloads (Overall): 484

Full text available: PDFPDF
We make progress in understanding the complexity of the graph reachability problem in the context of unambiguous logarithmic space computation; a restricted form of nondeterminism. As our main result, we show a new upper bound on the directed planar reachability problem by showing that it can be decided in the ...
Keywords: Directed graph reachability, planar graphs, unambiguous log-space

10
June 2007 CCC '07: Proceedings of the Twenty-Second Annual IEEE Conference on Computational Complexity
Publisher: IEEE Computer Society
Bibliometrics:
Citation Count: 6

We show that the st-connectivity problem for directed planar graphs can be decided in unambiguous logarithmic space.



The ACM Digital Library is published by the Association for Computing Machinery. Copyright © 2018 ACM, Inc.
Terms of Usage   Privacy Policy   Code of Ethics   Contact Us