Given simple polygons P and Q, their separation, denoted by (P;Q), is de ned to be the minimum distance between their boundaries. We present a parallel algorithm for nding a closest pair among all pairs (p; q), p 2 P and q 2 Q. The algorithm runs in O(logn) time using O(n) processors on a CREW PRAM, where n = jP j + jQj. This algorithm is time-optimal and improves by a factor of O(logn) on the ...

In this article, we discuss an efficient algorithm for tree mapping problem in XML databases. Given a target tree T and a pattern tree Q, the algorithm can find all the embeddings of Q in T in O(|T||Q|) time while the existing approaches need exponential time in the worst case.

Abs t rac t . Given simple polygons P and Q, their separagion, denoted by a(P, Q), is defined to be the minimum distance between their boundaries. We present an optimal O(N) algorithm for determining the separation of two simple polygons P and Q, where [P[ § [Q[ = [N[. The best previous algorithm for this problem is due to Kirkpatrick and has complexity O(N log N). In addition, a parallel versi...

Since the extensible markup language XML emerged as a new standard for information representation and exchange on the Internet, the problem of storing, indexing, and querying XML documents has been among the major issues of database research. In this paper, we study the twig pattern matching and discuss a new algorithm for processing ordered twig pattern queries. The time complexity of the algo...

We present Object Focused Q-learning (OF-Q), a novel reinforcement learning algorithm that can offer exponential speed-ups over classic Q-learning on domains composed of independent objects. An OF-Q agent treats the state space as a collection of objects organized into different object classes. Our key contribution is a control policy that uses non-optimal Q-functions to estimate the risk of ig...

This research merges the hierarchical reinforcement learning (HRL) domain and the ant colony optimization (ACO) domain. The merger produces a HRL ACO algorithm capable of generating solutions for both domains. This research also provides two specific implementations of the new algorithm: the first a modification to Dietterich’s MAXQ-Q HRL algorithm, the second a hierarchical ACO algorithm. Thes...

Given any fixed integer q ≥ 2, a q-monomial is of the format x1 i1 x s2 i2 · · · x st it such that 1 ≤ sj ≤ q − 1, 1 ≤ j ≤ t. q-monomials are natural generalizations of multilinear monomials. Recent research on testing multilinear monomials and q-monomials for prime q in multivariate polynomials relies on the property that Zq is a field when q ≥ 2 is prime. When q > 2 is not prime, it remains o...

We describe a new paradigm for implementing inference in belief networks, which consists of two steps: (1) compiling a belief network into an arithmetic expression called a Query DAG (Q-DAG); and (2) answering queries using a simple evaluation algorithm. Each node of a Q-DAG represents a numeric operation, a number, or a symbol for evidence. Each leaf node of a Q-DAG represents the answer to a ...

We study the approximability of the Max k-CSP problem over non-boolean domains, more specifically over {0, 1, . . . , q−1} for some integer q. We extend the techniques of Samorodnitsky and Trevisan [18] to obtain a UGC hardness result when q is a prime. More precisely, assuming the Unique Games Conjecture, we show that it is NP-hard to approximate the problem to a ratio greater than qk/q. Indep...