Empirical Performance Comparison Research Articles

Improving the efficiency of a hyperlinking-based theorem prover by incremental evaluation with network structures

Recently Lee and Plaisted proposed a theorem-proving method, the hyperlinking proof procedure, to eliminate duplication of instances of clauses during the process of inference. A theorem prover, CLIN, which implements the procedure was also constructed. In this implementation, redundant work on literal unification checking, partial unification checking, and duplicate instance checking is performed repetitively, resulting in a large overhead when many rounds of hyperlinking are needed for an input problem. We propose a technique that maintains information across rounds in shared network structures, so that the redundant work in each hyperlinking round can be avoided. Empirical performance comparison has been done between CLIN and CLIN-net, which is the theorem prover with shared network structures, and some results are shown. Problems related to memory overhead and literal ordering are discussed.

A splitting scheme for control variates

This paper details a new control-variate splitting scheme yielding an unbiased estimator of the mean response and an unbiased estimator of the variance of the first estimator. This scheme also yields an asymptotically exact confidence interval for the mean response. We present analytical and empirical performance comparisons of this scheme versus other control-variate procedures.

An empirical performance comparison of some variations of thek-d Tree andBD tree

Database applications very often require a sophisticated class of storage structures in order to answer different types of queries efficiently. This often dictates that the file should be organized on multiple keys. Several storage structures have been proposed to satisfy these needs. Most of these are a generalization of the storage structures used for managing one-dimensional data. Thek-d tree is one such example and it is a natural generalization of the standard one-dimensional binary search tree. Recently, a new storage structure, called theBD tree, was proposed to manage multidimensional data. This structure has good dynamic characteristics. Several variations are possible on the basick-d tree structure. This paper studies the performance implications of three variations. Further, it provides an empirical performance comparison of thek-d tree andBD tree in database applications.