[mod.ai] Seminars - Deductive and Relational Knowledge Bases

SKS@XX.LCS.MIT.EDU (Sunil Sarin) (02/18/86)

From: Sunil Sarin <SKS@XX.LCS.MIT.EDU>


           [Forwarded from the MIT bboard by SASW@MIT-MC.]

CCA Colloquium Series

DATE:      February 20, 1986-- Thursday
TIME:      10:00-11:00 a.m.
PLACE:     4th floor large conference room, Four Cambridge Center

TITLE:     Deductive Databases and a Relational Knowledge Base
           A Survey of Work at ICOT, Japan

SPEAKERS:  Haruo Yokota and Masaki Murakami (Institute for New
           Generation Computer Technology (ICOT--Japan) )


CCA (Computer Corporation of America) is located at Four Cambridge
Center, which is on Broadway, behind Legal Seafood.  Tell the
security desk you are visiting CCA and they will send you up to
CCA on the 5th floor.  Tell CCA's receptionist to call Barbara
Wong who will show you where the seminar is.  (If you can't
remember that, simply say you're here for the colloquium.)

Abstracts of works to be covered:

1. Deductive Database System based on Unit Resolution
   by Haruo Yokota, Ko Sakai, Hidenori Itoh

   This paper presents a methodology for constructing a deductive
   database system consisting of an intensional processor and a 
   relational database management system.  A setting evaluation
   is introduced.  The intensional processor derives a setting
   from the intensional database and a given goal and sends the
   setting and the relationship between setting elements to the
   management system.  The management system performs a unit 
   resolution with setting using relational operations for the
   extensional databases.  An extended least fixed point operation
   is introduced to terminate all types of recursive queries.

2. A Model and an Architecture for a Relational Knowledge Base
   by Hauro Yokota, Hidenori Itoh

   A relational knowledge base model and an architecture which
   manipulates the model are presented.  An item stored in the
   relational knowledge base is a term, and it is retrieved by
   unification operation between the terms.  The relational 
   knowledge base architecture we propose consists of a number
   of unification engines, several disk systems, a control processor,
   and a multiport page-memory.  The system has a knowledge compiler
   to support a variety of knowledge representations.

3. Formal Semantics of a Relational Knowledge Base
   by Masaki Murakami, Hauro Yokota, Hidenori Itoh

   A mathematical foundations for formal semantics of term relations
   [Yokota et al. 85] is presented.  A term relation is a basic data
   structure of a relational knowledge base.  It is an enhanced version
   of relational model in a database theory.  It may include syntactically
   complex structures such as terms or literals containing variables as 
   items of relations.  The items are retrieved with operations called
   retrieval-by-unification.  We introduce as a semantic domain of
   n-ary-term relations n_T_RELATIONS and define a partial order on them.
   We characterize retrieval-by-unification as operations on n_T_RELATIONS
   with monotone functions and greatest lower bounds.