Title
A Threshold Function for Harmonic Update
Abstract
Harmonic update is a randomized on-line algorithm which, given a random $m$-set of vertices $U(m)\subseteq\{-1,1\}^n$ in the $n$-dimensional cube, generates a random vertex $\bw\in\{-1,1\}^n$ as a putative solution to the system of linear inequalities: $\sum_{i=1}^n w_i u_i\geq0$ for each $\bu\in U(m)$. Using tools from large deviation multivariate normal approximation and Poisson approximation, we show that $\sqrt{n}\big/\!\sqrt{\log n}$ is a threshold function for the property that the vertex $\bw$ generated by harmonic update has positive inner product with each vertex in $U(m)$. More explicitly, let $P(n,m)$ denote the probability that $\sum_{i=1}^n w_i u_i\geq 0$ for each $\bu\in U(m)$. Then, as $n\to\infty$, $P(n,m)\to 0$ or $1$ according to whether $m=m_n$ varies with $n$ such that $m\gg\sqrt{n}\big/\!\sqrt{\log n}$ or $m\ll\sqrt{n}\big/\!\sqrt{\log n}$, respectively. The analysis also exposes the fine structure of the threshold function.
Year
DOI
Venue
1997
10.1137/S0895480195283701
SIAM J. Discrete Math.
Keywords
Field
DocType
large deviation multivariate,n w_i u_i,harmonic update,threshold function,fine structure,random vertex,poisson approximation,log n,dimensional cube,normal approximation,neural networks,randomized algorithm,polytopes,large deviations
Binary integer programming,Discrete mathematics,Combinatorics,Vertex (geometry),Combinatorial mathematics,Harmonic,Normal approximation,Polytope,Mathematics,Threshold function
Journal
Volume
Issue
ISSN
10
3
0895-4801
Citations 
PageRank 
References 
1
0.36
3
Authors
2
Name
Order
Citations
PageRank
Shao C. Fang1134.86
Santosh S. Venkatesh238171.80