Authors:
Susumu Yamasaki
1
and
Mariko Sasakura
2
Affiliations:
1
Okayama University, Tsushima-Naka, Okayama, Japan
;
2
Department of Computer Science, Okayama University, Tsushima-Naka, Okayama, Japan
Keyword(s):
Knowledge Acquisition, Algebraic Approach, Distributed System.
Abstract:
This paper is concerned with prevented information common in distributed knowledge base. The distributed knowledge is a framework to reflect knowledge acquisition and retrieval in a seminar class with participants. The presented accounts are listened to, by participants such that the participants may acquire knowledge. To make the acquired knowledge formal, it is restricted to rule-type and assumed as logically causal or algebraically structural. For such formalized knowledge, the meaning of knowledge may be considered by a consistent fixed point of the mapping associated with knowledge rules. The fixed point approach has complexity if the mapping is nonmonotonic (not monotonic), because the fixed point is not always available for the mapping. In this paper, we face such complexity caused by the nonmonotonic mapping which is reasonable from interactions between positive and negative informations in acquiring knowledge. With the assumption of some consistent fixed point existence, ret
rieval derivation to the ruled knowledge is inductively designed such that it may be sound with respect to the fixed point meaning of knowledge. The derivation adopts negation by failure, making adjustments between succeeding and failing cases, inherently involved in acquired knowledge. As regards the whole system in accordance with the seminar class, distributed knowledge base is formalized by taking a direct product of knowledge regarded as acquired by each participant. To make complexity of mutually interactive communications simpler and to possibly formulate common prevention conceived in the distributed knowledge base, we present a mapping associated with distributed knowledge base containing common negatives. Then the meaning of the whole system with common prevention information may be theoretically defined by a consistent fixed point of a mapping. A consistent fixed point of the mapping does not always exist, however, if it is definable, retrieval derivation in distributed knowledge base may be designed with an oracle of assumed prevention information in such a distributed knowledge base.
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