摘要:

An expert system for passive network synthesis and filter design, developed in an object-oriented environment, is presented. It has been implemented using a shell written in the language SMALL2ALK/V and is highly interactive. It has been conceived and developed mainly for educational purposes, and its implementation has demonstrated the suitability of the object-oriented approach and of the SMALLTALK environment for this kind of problem.

ISSN:0883-9514    

DOI:10.1080/08839519008927943

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper argues that existing adaptive control algorithms are limited in many practical applications because they lack the inclusion of human intelligence, knowledge, reasoning skills, and human-machine interaction. To solve these problems, an Intelligent Tuning Control (ITC) technique is presented. The TTC technique combines expert system technology and adaptive control techniques and integrates numeric computation with symbolic reasoning. Since most physical systems have uncertainties to some extent, an inexact reasoning method is proposed in the knowledge-based component. The TTC system is implemented using a Lisp-based expert system shell on an IBM PC. The utility of the TTC technique has been positively confirmed by simulation results.

ISSN:0883-9514    

DOI:10.1080/08839519008927944

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

In this paper a structured knowledge-based approach to the representation and scheduling of flexible manufactoring systems (FMSs) is described. Our approach is based on a structured conceptual representation (a KL-ONE-like Si-net representation formalism), extended with an instant-based temporal reasoning formalism. Furthermore, the approach integrates a particular extension to high-level Petri nets (PNs), structured timed colored Petri nets (STCPNs), for the modeling and simulation of the FMS. Such a representation scheme allows us to use SI-nets' good properties related to inference (classification and inheritance), which are lacking in PNs, and at the same time provides an extension toward an explicit representation for time. The integration of Si-nets with PNs is necessary because simulation and low-level coordination of FMSs require a procedural approach that is not within the aims of Si-nets. Therefore, procedural and symbolic levels, corresponding to the different hierarchical levels of the representation and control system of the FMS, coexist in the system. Using a qualitative terminology, we may also call them analog and symbolic knowledge. We assume that such a hybrid representation system may be useful, since a procedural representation, integrated within a logic formalism, can increase the expressive power without complicating the notation or the representation itself. The paper describes both the representational aspects and the modeling of the control system of the FMS, focusing on the interaction mechanisms among the different levels of representation. In particular, we show how an STCPN-based model can be automatically derived starting from the symbolic component of the system. A particular FMS case study, regarding a class of problems of resource-constrained multiproject scheduling (where projects are sets of tasks temporally related), is discussed.

ISSN:0883-9514    

DOI:10.1080/08839519008927945

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper describes the Nickel-Cadmium Battery Expert System-2, developed under MSFC/ NASA grant NAG8-I05. NICBES is intended to help in evaluation of the performance of the Hubble Telescope spacecraft battery power system. It provides a reasoning system supported by appropriate battery domain knowledge. NICBES-2 is an online, integrated, multitasking diagnostic expert system for nickel-cadmium battery management integrated with a Hubble Space Telescope telemetry data acquisition system. It is currently employed at the Marshall Space Flight Center on a Hubble Space Telescope battery test bed. NICBES diagnoses the performance of the Hubble Space Telescope spacecraft battery power system and alerts personnel to Us possible malfunctions. To achieve this, NICBES provides a reasoning system supported by appropriate battery domain knowledge. The reasoning system is integrated with a telemetry gathering system. The two subsystems cooperate in execution of their tasks and run within a Unix multitasking environment.

ISSN:0883-9514    

DOI:10.1080/08839519008927946

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor