Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!asuvax!ncar!noao!arizona!rick From: rick@cs.arizona.edu (Rick Schlichting) Newsgroups: comp.research.japan Subject: Kahaner Report: Jour JIFIP V14#1 (1991) & Trans JIFIP V31#6-12 (1990) Message-ID: <4301@optima.cs.arizona.edu> Date: 15 Jun 91 02:03:14 GMT Sender: rick@cs.arizona.edu Lines: 772 Approved: rick@cs.arizona.edu [Dr. David Kahaner is a numerical analyst visiting Japan for two-years under the auspices of the Office of Naval Research-Asia (ONR/Asia). The following is the professional opinion of David Kahaner and in no way has the blessing of the US Government or any agency of it. All information is dated and of limited life time. This disclaimer should be noted on ANY attribution.] [Copies of previous reports written by Kahaner can be obtained from host cs.arizona.edu using anonymous FTP.] To: Distribution From: David K. Kahaner, ONR Asia [kahaner@xroads.cc.u-tokyo.ac.jp] Re: Jour JIFIP V14#1 (1991) & Trans JIFIP V31#6-12 (1990) 14 June 1991 This file is named "jifip14.abs" ABSTRACT. Titles and abstracts from Jour JIFIP V14#1 (1991) and titles from Trans JIFIP V31#6-12 (1990). All the papers are in English JOURNAL OF INFORMATION PROCESSING Vol. 14. No. 1, 1991 Almost Boolean Algebraic Computation of LALR (1) Look-Ahead Sets Hiroyuki Anzai (Faculty of Engineering, Kyushu Institute of Technology) In order to obtain an LALR (1) parser from a given grammar, it is necessary to construct an LR (0) automation and to compute LALR (1) Look- Ahead sets. This paper presents a new method for doing so, based on the linear algebra-like approach instead of the traditional graph theoretical one. After pointing out that the regular language generated from the empty set is isomorphic to Boolean algebra, this paper shows that the above problems can be solved by partially reducing them to problems of this simplest language, Boolean algebra, in such a manner that unknown sets are defined by simultaneous equations each of whose coefficients is a Boolean number. For a given BNF, equations of this kind defining the state transition of an LR (0) automation are given and solved. Follow sets are similarly defined and solved. Each solution is a formula for computing the desired sets, whose form is the product of the closure of a Boolean matrix and a vector of either Boolean numbers or sets of symbols. Finally, each Look-Ahead set is obtained as a union of properly selected Follow sets. Until now, this kind of computation has been done in an iterative manner of set computation on the equations until the sets obtained become unchanged. Instead, this paper gives a formula for computing them by almost Boolean matrix computation. A Nonmonotonic Temporal Logic and Its Kripke Semantics Yasushi Fujiwara, Shinichi Honiden (Systems & Software Engineering Laboratory, Toshiba Corp.) Human commonsense reasoning is at the same time nonmonotonic and temporal. This paper proposes a logic for nonmonotonic temporal reasoning. The nonmonotonic temporal logic "autoepistemic temporal logic" (ATL) is an extension of both autoepistemic logic, a kind of nonmonotonic logic, and propositional temporal logic (PTL). A spatio- temporal logic ST5, which is suitable for reasoning about multiprocess networks, is also proposed, and a close relationship is exhibited between the semantics of ATL and ST5. Stable expansions of premises of a certain type are then characterized in terms of statewise autoepistemic stable expansions. The result may also provide a general approach to constructing nonmonotonic logic with possible-world semantics. Accurate Reconstruction of a 3D Object Composed of Multiple Surfaces Kazufumi Kaneda, Yutaka Wakasu, Eihachiro Nakamae (Faculty of Engineering, Hiroshima University) Mineo Yasuda, Akinao G. Sato (School of Medicine, Hiroshima University) In order to observe in detail the internal structure of a multi- layered object consisting of various elements, it is very important to reconstruct the original object from its cross-sectional data and display the inner along with the outer appearance of the reconstructed object. This paper describes a technique for reconstructing a 3D object from complex contours on the cross-sections efficiently and faithfully. The proposed method succeeds even when the object's shape varies radically between successive cross-sections: cross-sections with radically different contours and/or radically different contour line segments are automatically supplemented. The usefulness of the proposed method is demonstrated with some semitransparent and stereoscopic displays of a reconstructed mouse embryo. A Dynamic Algorithm for Placing Rectangles without Overlapping Takeshi Tokuyama (IBM Research, Tokyo Research Laboratory) Takao Asano (Faculty of Science and Technology, Sophia University) Shuji Tsukiyama (Faculty of Science and Engineering, Chuo University) We consider the dynamic allocation problem of rectangles such that a mixed sequence of insertions and deletions of rectangles in a rectangular board is executed without any pair of rectangles overlapping each other. We present an O (n log log n) time algorithm for insertion of a rectangle if n rectangles have been already placed in the board. We solve the problem by reducing it to the contour construction problem on a special class of arrangements of rectangles. Roughly Sorting: A Generalization of Sorting Yoshihide Igarashi (Department of Computer Science, Gumma University) Derick Wood (Department of Computer Science, University of Waterloo, Canada) A sequence `=(a1, ...., an) is k-sorted if and only if for all 1