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We describe a language and protocol intended to support interoperability among intelligent agents in a distributed application. Examples of applications envisioned include intelligent multi-agent design systems as well as intelligent planning, scheduling and replanning agents supporting distributed transportation planning and scheduling applications. The language, KQML for Knowledge Query and Manipulation Language, is part of a larger DARPA-sponsored Knowledge Sharing effort focused on developing techniques and tools to promote the sharing on knowledge in intelligent systems. We will define the concepts which underly KQML and attempt to specify its scope and provide a model for how it will be used. Notice of DRAFT Status. This document presents the current draft of a specification under consideration by the DARPA Knowledge Sharing Effort. It is provided for information purposes, and should be treated as representing only the current status of discussions. It should not be interpreted a...

CoBase, a cooperative database, is a new type of distributed database that integrates knowledge base technology with database systems to provide cooperative (approximate and conceptual) query answering. Based on the database schema and application characteristics, data are organized into conceptual (type abstraction) hierarchies. The higher levels of the hierarchy provide a more abstract data representation than the lower levels. Generalization (moving up in the hierarchy), specialization (moving down in the hierarchy) and association (moving between hierarchies) are the three key operations in deriving cooperative query answers. Relaxation in CoBase can also be specified explicitly in the query by the user or calling program through cooperative operators. We have extended SQL to CSQL by adding cooperative primitives. We describe the CoBase software implementation, including an inter--module data protocol that provides a uniform module interface. This modular approach provides flexibil...

Two different aspects of data management are addressed by description logics (DL) and databases (DB): the semantic organization of data and powerful reasoning services (by DL) and their efficient management and access (by DB). It is recently emerging that experiences from both DL and DB should profitably cross-fertilize each other, and a great interest is rising about this topic. In the present paper our technique, that allows uniform access -- by means of a DL-based query language -- to information distributed over knowledge bases and databases, is briefly reviewed. Our extended paradigm integrates the separately existing retrieving functions of description logics management systems (DLMS) and of database management systems (DBMS) in order to allow, via a query language grounded on a DL-based schema knowledge, uniformly formulating and answering queries, so that uniform retrieval from mixed knowledge/data bases is possible. In particular, some new developments extending those presente...

Semantic data models for database systems provide powerful tools to assist database administrators in designing and maintaining schemas, but provide little or no direct support for users of the database. Some research has been done on mapping user models of a domain to the underlying database using semantic schemas. Little has been done, however, on mapping conceptually meaningful data structures to a database lacking a semantic schema, or to a multi-database system that lacks a consistent semantic schema. We argue for the appropriateness of a knowledge representation language as a language for describing the database schema, user data structures, and the mapping between them; present a problem domain in which an existing relational database without a semantic schema must be accessed by a knowledge-based application; and describe our implementation of a system that provides access to a relational database from a KL-ONEstyle knowledge representation language. 1 Introduction The integra...

We describe a language and protocol intended to support interoperability among intelligent agents in a distributed application. Examples of applications envisioned include intelligentmulti-agent design systems as well as intelligent planning, scheduling and replanning agents supporting distributed transportation planning and scheduling applications. The language, KQML for Knowledge Query and Manipulation Language, is part of a larger DARPA-sponsored Knowledge Sharing e#ort focused on developing techniques and tools to promote the sharing on knowledge in intelligent systems. e will de#ne the concepts which underly KQML and attempt to specify its scope and provide a model for how it will be used. Please send comments to Tim Finin, Computer Science, University of Maryland, Baltimore MD 21228; #nin@cs.umbc.edu; 410-455-3522 or to Don Mckay,Paramax Systems Corporation, PO Box 517, Paoli PA 19301; mckay@prc.unisys.com; 215-648-2256. This work is partly supported byDARPA and Rome La...

this paper, after briey showing the importance of an integrated view of description logics and databases, our approach to this topic is presented. Our technique allows uniform access { by means of a DL-based query language { to information distributed over knowledge bases and databases. The separately existing retrieving functions of description logics management systems and of database management systems are integrated, in our extended paradigm, in order to allow, via a query language grounded on a DL-based schema knowledge, uniformly formulating and answering queries and, thus, uniform retrieval from mixed knowledge/data bases

This chapter proposes the use of the type abstraction hierarchy (TAH) as a framework for deriving cooperative query answers (CQA). The TAH integrates abstraction with the subsumption (is-a) and composition (partof) semantics found in the type hierarchy. This framework provides a multi-level object representation that is an important aspect of cooperative query answering. Patterns, which specify one or more conditions on an object, are introduced as a small granularity structure with specific semantic information. Cooperative query answering uses the TAH and patterns to provide query relaxation, generalization and specialization. Relaxation can be explicitly controlled by the user, implicitly performed by the system, or both. An explanation system is also included to present the relaxation path as well as a nearness measure between the approximate answer and the exact answer. The operations required for CQA may be added to any conventional query language. As an example, we present CSQL...

Modern knowledge systems for design typically employ multiple problem-solving methods which in turn use different kinds of knowledge. The construction of a heterogeneous knowledge system that can support practical design thus raises two fundamental questions: how to accumulate huge volumes of design information, and how to support heterogeneous design processing? Fortunately, partial answers to both questions exist separately. Legacy databases already contain huge amounts of general-purpose design information. In addition, modern knowledge systems typically characterize the kinds of knowledge needed by specific problem-solving methods quite precisely. This leads us to hypothesize method-specific data-toknowledge compilation as a potential mechanism for integrating heterogeneous knowledge systems and legacy databases for design. In this paper, first we outline a general computational architecture called HIPED for this integration. Then, we focus on the specific issue of how to conver...

Generality and scale are important but difficult issues in knowledge engineering. At the root of the difficulty lie two challenging issues: how to accumulate huge volumes of knowledge and how to support heterogeneous knowledge and processing. One approach to the first issue is to reuse legacy knowledge systems, integrate knowledge systems with legacy databases, and enable sharing of the databases by multiple knowledge systems. We present an architecture called HIPED for realizing this approach. HIPED converts the second issue above into a new form: how to convert data accessed from a legacy database into a form appropriate to the processing method used in a legacy knowledge system. One approach to this reformed issue is to use method-specific compilation of data into knowledge. We describe an experiment in which a legacy knowledge system called Interactive Kritik is integrated with an ORACLE database. The experiment indicates the computational feasibility of method-specific data-to-knowledge compilation.