Teknowledge Corporation

Cimflex Teknowledge Corporation

Jay S Lark

James S Bennett

Lee D Erman

William J Clancey

Frederick Hayes-Roth

A Carlisle Scott

Michael Fehling

Philip E London

A Multi-Level Architecture for developing intelligent computer systems composes computational modules uniformly across diverse developmental framework. The modules interact via message passing and are assembled to form application-specific systems. A first level of the Multi-Level Architecture includes a cooperative operating system which provides support for message passing and resource allocation and is preferably based on a module-oriented programming (MOP) model. The first level, for example, defines a virtual machine which is mapped onto an underlying hardware and operating system environment. A second level of the Multi-Level Architecture supports a plurality of application-independent problem-solving frameworks (PSF's) or programming environments for building modules and combining modules of different frameworks into complex systems. A third level of Multi-Level Architecture includes a plurality of knowledge processing modules ranging from specialized modules to skeletal systems which provide nearly complete solutions to application problems. For building an application-specific system, domain-specific knowledge is added on top of the third level and typically a selected skeletal system is customized. Extension or refinement of the application-specific system is accomplished by replacing existing modules with more complex modules or by using additional modules. The Multi-Level Architecture is particularly useful for building a plan monitoring and replanning system which monitors whether an initially valid design remains valid prior to its implementation, incrementally modifies the design to insure validity despite changing conditions, applies control knowledge to control sequencing among the monitoring and replanning functions, and also applies knowledge to explain the nature of design failures.

Architecture for composing computational modules uniformly across

A tool is used for knowledge engineers for building and interpreting a knowledge base having separate portions encoding control knowledge, factual knowledge, and judgmental rules. The tool has an inference engine applying the judgmental rules according to a built-in control procedure defining discrete states or control steps during a consultation with a user. The control knowledge is encoded in an applicative and imperative language defining control actions to be executed during interruption of the built-in control procedure at specified control steps. Since the control knowledge is explicit and results in the modification of data only in a precisely defined fashion, the tool can be used to build knowledge systems that can always explain their conclusions and reasoning, and that are intelligible and modifiable. To provide transparent representation of control knowledge as well as factual knowledge, the knowledge base is preferably organized into distinct frames which include the rules; control blocks separately encoding the control knowledge; and classes which become instantiated, attributes which take on values describing the class instances, class types, legal value hierarchies, and user-defined functions, which all encode factual knowledge. The knowledge engineer may provide control blocks to be executed at the start of the consultation, after the instantiation of specified classes, when a value for a specified attribute is to be determined, after a specified attribute is determined, and upon explicit invocation by another control block. The tool can also implicitly determine subsumed attributes.

Knowledge engineering tool

A knowledge system has a hierarchical knowledge base comprising a functional decomposition of a set of elements into subsets over a plurality of hierarchical levels, a plurality of predefined functions or conditions of the elements within the subsets of a plurality of the hierarchical levels, and a predefined set of operations to perform on a user-defined set of elements responsive to the functional knowledge base. Preferably, the knowledge base is defined declaratively by assigning parent sets to offspring subsets to define the hierarchy, by indicating the conditions of the subsets which satisfy the predefined functions and by writing task blocks in an imperative language defining the sequence of operations to perform on the user-defined set of elements. Preferably the operations include matching, configuring and expanding the user-defined set of elements into the defined subsets of individual elements and evaluating the predefined functions, and the operations are executed recursively. In a specific embodiment the elements are available components for a system or item of manufacture, and the subsets of elements are sub-assemblies or functionally related components. The predefined functions define condition-action constraints to insure that the sub-assemblies have compatible components. Such a knowledge system has general applicability, is easy to maintain and incrementally modify, has transparent representation of the functional decomposition and the configuration operations, and provides explanation for an assessment of the configuration.

Hierarchical knowledge system

Growing community of inventors

Palo Alto, CA, United States of America

Jay S Lark