13025235
Query Evaluation of Deductive Database by MGTP and its Application to Data Mining
41945159
On a Sufficient Condition for the Existence of Most Specific Hypothesis in Progol
In this paper, we give a sufficient condition for the existence of the most specific hypothesis (MSH) in Progol. Muggleton [2] showed that for any first order theory (background knowledge) B and a single clause (a positive example) E, there exists the most specific hypothesis ¬bot(B, E) which satisfies B ≈ ¬,bot(B, E) ⊨ E and for any hypothesis H satisfying B ≈ H ⊨ E, H entails bot(B, E) assuming that hypotheses are all single clauses. Yamamoto[8] gave a counter example and indicated that Muggleton's proof contains error. He also gave a sufficient condition under which the MSH exists. In this paper, we give another and more realistic sufficient condition to guarantee the existence of the MSH.
37726421
A Framework for Interactive Problem Solving Based on Interactive Query Revision
Logic programming has been widely used because of the clearness of its semantics and its extensibility. Many inference systems have been proposed using a logic programming framework. But few of these have studied logic based man-machine interaction, apart from systems based on incremental query [Emden 1985]. Incremental query allows users to enter a part of queries incrementally instead of entering the whole query at once, as in Prolog. In this paper we investigate essential concepts of interactive problem solving and generalize incremental query further. And we propose a new query model for logic programming, which we call interactive query revision. Interactive query revision allows a user to modify queries and hypotheses and to act as a part of the inference engine, in addition to entering queries incrementally. We apply interactive query revision to an interactive LSI layout system.
34444111
Modularization and abstraction in logic programming
In knowledge information processing, the structuring of knowledge and algorithms is one of the key issues. The goal of this work is to introduce the concepts and mechanisms of abstraction, modularization and parameterization into logic programming, which is one of the preliminary steps toward creating a kernel language for fifth generation computer systems.
2293804
GHC - A Language for a New Age of Parallel Programming
A parallel logic programming language GHC, proposed by Ueda (1985), is now playing a very important role in the Fifth Generation Computer Project. It is a successor of Relational Language (Clark and Gregory 1981), Concurrent Prolog (Shapiro 1983) and Parlog (Clark and Gregory 1984). Since GHC is totally based on parallelism, it provides a genuine tool for parallel programming. It encourages programmers to write parallel algorithms and therefore gives a foundation of parallel programming. We have also developed a program transformation technique for GHC programs which preserves the external behaviour of the original programs. To show the validity of the transformation technique, we have developed a formal semantics of possibly non-terminating GHC programs. The highly parallel prototype hardware of our project is now being developed to support the efficient execution of GHC programs.
46330306
OR-Parallel Optimizing Prolog System: POPS. Its Design and Implementation in Concurrent Prolog
This paper describes a computational model of an OR-Parallel Optimizing Prolog System (POPS) based on a graph-reduction mechanism and multi-processing. POPS has the following features: 1) Programs are executed in OR-Parallel. 2) The same subcomputations are shared. 3) Left recursive rules can be handled without entering an infinite loop. At present, POPS is implemented in Concurrent Prolog supporting AND-Parallel execution and process synchronization mechanisms. This implementation shows that the OR-parallel execution of a logic program can be achieved by an AND-parallel execution mechanism.
11394601
On the number of securities which constitute an efficient portfolio
The purpose of this paper is to discuss the relationship between the number of securities which constitute an efficient portfolio as defined by the standard mean-variance portfolio selection model and the number of periods used to compute the efficient portfolio. It is shown that the number of data gives the upper bound of the number of securities which constitute an efficient portfolio, when each efficient portfolio is unique for a given expected return. Empirical tests based on actual return data show that this upper bound is very tight when the number of data is small. However, when more data are used, the upper bound becomes looser. This result is incompatible with the market efficiency. These empirical tests also indicate that a very tight upper bound often causes a degenerate case ensuring zero-variance portfolios.