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Upcoming Seminars
Department of Mathematics & Computer Science
Title: "Algorithm for Learning From a Random Walk Oracle"
Speaker: Xiaolin Yang
Date: Thursday, July 23
Time: 2:00 pm - 3:00 pm
Place: 351 College Hall
Abstract: Learning Disjunctive Normal Form (DNF) and Threshold of
Parity (TOP) functions are well-studied problems in computational
learning theory. Under different learning models we can achieve
different time complexities with respect to the size of the
input. The best results to date have been obtained in an active
learning model based on membership oracle queries, where
algorithms exist that nearly exponentially outperform the best
current TOP algorithms for the passive learning model based on
uniform random instances provided by an example oracle. In this
thesis, I consider using an oracle whose power lies in between
membership and example oracles, the random walk oracle. I first
study a topic which is closely related to certain learning
algorithms, specifically, a heuristic algorithm for estimating
the sum of squares of Fourier coefficients. Then I propose a new
algorithm for learning under a random walk oracle and compare the
performance of this algorithm with an algorithm previously
proposed by Jackson and Wimmer. The performance of these two
algorithms is evaluated empirically based on experiments on
linear threshold functions, a special case of TOP. Finally, I
prove a theorem showing how to efficiently generate a richer
subclass of TOP functions from linear threshold functions, which
could allow for broader testing of these algorithms.
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