Title
Asymptotic variance of random symmetric digital search trees
Abstract
Asymptotics of the variances of many cost measures in random digital search trees are often notoriously messy and involved to obtain. A new approach is proposed to facilitate such an analysis for several shape parameters on random symmetric digital search trees. Our approach starts from a more careful normalization at the level of Poisson generating functions, which then provides an asymptotically equivalent approximation to the variance in question. Several new ingredients are also introduced such as a combined use of the Laplace and Mellin transforms and a simple, mechanical technique for justifying the analytic de-Poissonization procedures involved. The methodology we develop can be easily adapted to many other problems with an underlying binomial distribution. In particular, the less expected and somewhat surprising n (logn)(2)-variance for certain notions of total path-length is also clarified.
Year
Venue
Keywords
2010
DISCRETE MATHEMATICS AND THEORETICAL COMPUTER SCIENCE
Digital search trees,Poisson generating functions,Poissonization,Laplace transform,Mellin transform,saddle-point method,Colless index,weighted path-length
Field
DocType
Volume
Mellin transform,Generating function,Discrete mathematics,Binomial distribution,Combinatorics,Normalization (statistics),Laplace transform,Algorithm,Poisson distribution,Delta method,Asymptotic analysis,Mathematics
Journal
12.0
Issue
ISSN
Citations 
2.0
1462-7264
12
PageRank 
References 
Authors
0.71
40
3
Name
Order
Citations
PageRank
Hsien-Kuei Hwang136538.02
Michael Fuchs2528.98
Vytas Zacharovas3212.42