Object-oriented Knowledge-based System Research Articles

A knowledge‐based system for electric motors compliance verification in a multinational‐level company

AbstractElectric motors are highly customizable products that have to meticulously comply with the client's needs, commercial and legal requirements of each market. In this context, the configure‐to‐order (CTO) approach allows the user to define the product configuration at the time of the order and the supplier to develop a product that meets the customer's needs. This paper presents an object‐oriented knowledge‐based system (OOKBS) that integrates rule‐ and case‐based reasoning to verify the compliance of a variant‐rich and complex product—electric motors—in a multinational‐level company. The system adopts a modular structure to evaluate distinct compliance aspects, such as technical constraints and commercial requirements, and to improve the compliance assessment based on the designs of motors previously sold. The work targeted a product line with significant market share in North America, and is the result of a collaboration among the following teams: product compliance, international sales, engineering systems, and product engineering. In total, the system development involved nine experts from these areas. This study has the originality of presenting a product configuration system (PCS) that integrates rule‐based and case‐based approaches to verify the compliance of a modular product. The results indicate a reduction of 73% of internal technical queries within the prototype scope. Moreover, the system usability tests highlight the completeness of outcomes, quick access to information, and easy integration of automatic product compliance verification into the company's design flow. Furthermore, we discussed how the system was effectively implemented in a design routine based on both concurrent engineering and CTO scenarios.

Object-Oriented Knowledge-Based System for Distribution Transformer Design

The first stage in any machine design process involves a substantial heuristic exercise to select the machine best suited to a set of specifications. The second stage obtains the dimensions of a selected machine and a design that satisfies specifications. The final stage usually involves optimization and the finite-element method. We present an object-oriented knowledge-based system for distribution transformer design with the first two stages fully automated. We describe the rationale for the system, the architectural design procedure, and the approach taken in constructing the system for practical applications.

R-DEVICE

In this paper we present R-DEVICE, a deductive object-oriented knowledge base system for reasoning over RDF metadata. R-DEVICE imports RDF documents into the CLIPS production rule system by transforming RDF triples into COOL objects and uses a deductive rule language for reasoning about them. R-DEVICE is based on an OO RDF data model, different than the established triple-based model, which maps resources to objects and encapsulates properties inside resource objects, as traditional OO attributes. In this way, fewer joins are required to access the properties of a single resource resulting in better inferencing/querying performance, as it is experimentally shown in the paper. Furthermore, RDF can interoperate seamlessly with other Web data models and languages. The descriptive semantics of RDF may call for dynamic redefinitions of resource classes, which are handled by R-DEVICE effectively. Furthermore, R-DEVICE features a powerful deductive rule language for reasoning on top of RDF metadata. The rule language includes features such as normal and generalized path expressions, stratified negation, aggregate, grouping, and sorting functions. The rule language supports a second-order syntax, which is efficiently translated into sets of first-order logic rules using metadata, where variables can range over classes and properties, so that reasoning over the RDF schema can be made. Users can define views that are materialized and incrementally maintained by translating deductive rules into CLIPS production rules that preserve truth. Users can choose between an OPS5/CLIPS-like and a RuleML-like syntax. Finally, users can define and use functions through the CLIPS host language.

Representing geotechnical properties in a knowledge-based system

A knowledge-based system for the estimation of geotechnical design parameters is described. The form of representation and the way in which this has been implemented using an object-oriented knowledge-based system development environment (ProKappa) are explained. Three knowledge bases for Ground Types, Ground Parameters and `Typical' Values have been established as object hierarchies. The knowledge bases hold ranges of typical values for geotechnical parameters for a wide variety of ground types. Different qualitative properties of the ground are also represented. A user interface allows identification of the soil or rock type for which properties are to be estimated and this is matched at the appropriate level of detail within the knowledge bases. Estimation can be done both in terms of the ground type and qualitative properties such as plasticity, consistency, mineralogy, particle shape, etc. The knowledge representation scheme adopted allows combinations of qualitative properties to be considered. A knowledge acquisition facility has also been provided to allow users to add their own knowledge to the system. Users can add new parameters, extend the number of qualitative properties considered and even establish new ground types.

Object-oriented knowledge-based system for image diagnosis

In this article the design and implementation of a high-level image diagnosis system are described. A knowledge-based system, OOI, has been developed to incorporate the image processing abilities. It employs a robust control strategy in the object-oriented approach that minimizes the amount of domain-specific control knowledge. Knowledge objects are constructed that embed specialized methods or metaknowledge in image processing. They work independently of each other. The highly modular architecture allows the knowledge engineers to modify the knowledge without worrying about any unexpected side effects. Reasoning in OOI proceeds in both top-down and in bottom-up schemes. The system has been tested in medical image analysis. Cancer cell lesion classification is used as an application domain to illustrate how image diagnosis can be implemented in our system. Results attest to the efficacy of this framework in both image recognition and diagnosis.

Development of an object-oriented knowledge-based system for power electronic circuit design

A knowledge-based (expert) system (KBS) approach to power electronic circuit design is presented. The system, a power electronics and control tool, designated PECT, is written using Smalltalk-80, which integrates the artificial intelligence techniques of production rules for high-level knowledge representation. PECT embraces elements of power circuitry design and contains such features as selection of the circuit configuration, control facility, and power device best suited to a given application. It is interfaced with HSPICE, the commercial version of a general-purpose circuit simulation package, and a semiconductor power device library. Data retrieved from this library is converted into an object-oriented representation database. Analytical hierarchy process reasoning is performed on this data to aid the device selection process. System architecture as well as target design realization process are detailed. The criteria of development and the factors and requirements in building the PECT are also included. An example simulation is given representing a buck-boost converter using a gate turn-off thyristor (GTO) switch model.

Prototype Knowledge-Based System for Corrective Maintenance of Pavements

Corrective maintenance of pavements involves identifying the existing problems and selecting the most effective remedial measure to correct the deficiencies. Regular inspection and minor repairs ensure a satisfactory level of pavement performance, and it prevents the occurrence of future major problems. Due to the unbalanced proportion of too many pavements in need of repairs and too few experienced engineers to carry out the task of condition and treatment evaluation, pavement inspections and necessary repairs are irregular and are not performed as often as needed. More often than not, methods of rehabilitation are more practically available than competent engineers. The dissemination of expert knowledge about pavement inspection and treatment evaluation by means of knowledge-based systems to a wider group of engineers (such as local maintenance personnel) is needed. This paper discusses the maintenance requirements in Ontario, Canada, and presents the development of a prototype object-oriented knowledge-based system for the inspection and repair of pavements.

Knowledge-based model validation support for end-user computing environments

Encouraging individuals to use corporate data and build computer-based decision models locally, while simultaneously ensuring that the modelling activity is consistent with corporate policies and guidelines poses a challenge to many organizations. Although it is desirable to encourage user autonomy in decision making, it is equally imperative to assure appropriate quality of the decisions made. In this paper interdependencies within the organizational decision making activity are used to identify some generic categories of support required to maintain consistency and quality in end-user model construction. Five distinct cases of model building activity in an end-user computing environment are described and support for ensuring consistency in user constructed models for two of these cases is discussed. An object-oriented knowledge-based system that provides such support has been developed; the architecture of this system is described. System implementation and interaction is illustrated with the aid of a financial budgeting application.

CMS: An intelligent knowledge-based tool for organizational procedure modeling and execution

The design and implementation ofCMS (Collaboration Management System), an intelligent knowledge-based tool designed to help organization members execute organizational procedures is described. CMS is aimed at automating the relationships and roles of organization members, rather than just transactions, so that a procedure can be executed by groups of problem solvers acting autonomously, cooperatively, and collaboratively to achieve the collective goal. This collaborative process model supports the definition, execution, monitoring, and dynamic modification of organizational procedures and is implemented as an object-oriented knowledge-based system. Our primary intent is to document the implementation strategy we employed, which is based on the integration of object-oriented programming into the logic programming environment of Prolog. This integration proves to be a powerful knowledge-based application development environment that preserves the best features of each technology within the system. Thus, CMS inherits its capability of structuring and organizing problem-solving knowledge of the application from object-oriented technology and its expressive power, pattern matching, and automatic backtracking characteristics from logic programming.

An object-oriented knowledge-based system for automating the routing process in a manufacturing environment

The use of intelligent computer applications is an effective means to improve time management and to increase the competitiveness of any business. The developed application is designed to minimize the time it takes to meet both a company's and its customer's needs. The Blank and Steel Socket Routing System implements the first step in determining the cost of a manufactured part. The system automates the process for determining all the operations performed on the factory floor on a requested part. The complete list of operations includes information on the specific work-centers needed to manufacture the part, and the various times that the centers will be occupied. Knowing the utilized work-centers and the length of their use, the cost of manufacturing the part can be easily approximated and, therefore, can be quickly communicated back to the customer. The Black and Steel Socket Routing System is implemented with an object-oriented knowledge-based tool. Furthermore, this program is one of a multi-part programming system embedded in a Computer Integrated Manufacturing environment. The object-oriented knowledge-based system is developed via the Automated Reasoning Tool for Information Management (ART-IM) software. ART-IM provides an inference engine that utilizes the function of parallel processing. By using the RETE algorithm, an opportunistic parallel rule execution algoritm, ART-IM enables large expert-system programs that contain a large number of rules to be read and processed rather quickly and efficiently, as opposed to the traditional methods of programming with “If...then”-based structures. The knowledge-based system contains the information regarding the various characteristics of any given part design. With this information, the part routing program searches through the rules pertaining to the given design, which is based upon the dimensions of the part entered in a data file. This data file can be altered by the design engineer to facilitate a much quicker process of obtaining the various operations to be performed for various design patterns. The implementation of this knowledge-based routing system significantly reduces the amount of time it had taken to determine the operations needed to be performed for a given part design. Furthermore, this system lowers the frustration level experienced by the design engineers, as there was no further need to scan large databases in determining the routing operations. Before the use of this system, the probability of error was significantly high and, therefore, contributed to the inefficiency of the process. The automated program, therefore, increases the reliability of the process.

Integration of scientific data and formulae in an object-oriented knowledge-based system

An object-oriented knowledge based system has been developed to store and manipulate scientific knowledge in the form of data and formulae encountered in conventional textbooks on science and engineering. The formulae are input in the same form as they are written in, in terms of the well known symbols used by engineers and scientists. The system interprets the symbols as representing scientific quantities and links them with the underlying data and methods in the knowledge base. By linking data about scientific quantities with one or more appropriate formulae, it is shown that the knowledge base can be used for simple problem solving. The development of the system on a Sun Sparcstation was facilitated by the use of an object-oriented environment, Objectworks C++.

Selection and sequencing of hazardous waste treatment processes: A knowledge-based systems approach

A commercially available software package was used to develop a prototype object-oriented knowledge-based modeling system to aid in the determination of hazardous waste treatment process sequence. For the prototype system, 15 waste contaminants were chosen for consideration. Knowledge describing 10 treatment processes was collected and incorporated into separate program modules so only those processes required were considered by the system. The knowledge-based system was established so that the user can specify the treatment objectives that the treatment sequence is intended to satisfy. The prototype system is intended to demonstrate a potential use of knowledge-based systems in both the design and the operational management of hazardous waste treatment facilities. From a design perspective, such a system could be used to determine effective treatment sequences for expected waste types, thus helping to determine which processes should be included in a proposed facility. From an operational management perspective, such a system could be used to determine the treatment sequence required for a waste to meet treatment objective contaminant levels.

Objet-Sexi: Objects, Rules and Fuzzy Functions for Identification

The main aspects of an Object-Oriented knowledge-based system for process identification are presented. Its knowledge base relies on a mixed structure, implemented within an object-oriented representation as well as modules of production rules. Objects allow an easy implementation, updating and extension of the structured theoretical knowledge about models, transfer functions, polynomials, etc. Relatively small rule bases are attached to the slots of the objects and include the empirical knowledge about process identification. Fuzzy compatibility functions are used for the numerical-symbolic conversion of values supplied by the computations of the parameter estimation module. The search strategy for an “optimal” model structure has been implemented within a dedicated meta knowledge base.

An object-oriented knowledge-based system for manufacturability of printed wiring boards

Design for manufacturability has been proved to be a solution that avoids the problems created by design not amenable to manufacturing. The designer should be aware of the manufacturing constraints to achieve the design for manufacturability. The rapid change in printed circuit board aanufacturing with the induction of surface mounted components and robotic assembly has changed the scenario of the design. The high-density packaging capability of surface mounted technology has contributed enormously to the development of new trends in printed wiring board manufacturing. Pwbma, Printer Wiring Board Manufacturability Advisor (printed wiring board is another name for printed circuit board), a knowledge-based system, is developed to capture this new technology and its interaction with the existing through-hole mounting technology. Rules and guidelines pertaining to manufacturability of the board are formulated and incorporated into the knowledge base in building the system, which is built on an object-oriented paradigm. The importance of the object-oriented approach, the implementation of the object-oriented paradigm, object-oriented programming using Smalltalk-80, and the hierarchical rule structure paradigm are discussed. The implementation of meta-level to increase the efficiency of the system is also presented. Furthermore a rating system is introduced to rank various designs. Pwbma is capable of suggesting design modifications at the early stage of design to eliminate the manufacturing problems in the later phase of board production. The system is very easy to use with a broad user interface.

The application of knowledge-based systems to the simulation of gold extraction processes

Most unit operations and processes of gold extraction are ill-defined and cannot be simulated adequately by conventional mathematical models. This is caused mainly by the complex chemistry and mineralogy of most ore slurries. An object-oriented knowledge-based system (KBS) is proposed here for the dynamic simulation and fault-diagnosis of various sub-processes in the extraction of gold. Two approaches are used, viz.: (1) where the parameters of simple empirical expressions are related to a data base via an evolution of operating conditions, and (2) where the dynamic behaviour of a system is finger-printed by the gradient of change of a state variable. The first approach is applied to the simulation of gold leaching in batch reactors, cascades of continuous reactors, and countercurrent Kamyr towers. The depletion of cyanide and/or oxygen is also taken into account.The second approach is applied to CIP and CIL cascades. The centre (deep knowledge) of this model is a database containing concentration-time data and an accompanying generalized kinetic model. The knowledge-base is defined by various facts, objects, rules and functions, which capture both deep as well as shallow knowledge regarding the process. Furthermore, it is explained how KBS simulation can be used in fault-diagnostics and the identification and characterisation of ores, slurries and adsorbents. The proposed KBS produces realistic simulations of experimental and published data. It is evident that the accuracy of prediction is entirely dependent on the accuracy and population density of the data base. In most cases, dynamic simulation by KBS has reduced CPU time drastically in comparison with the numerical solution of more phenomenological models.

Encore: an object-oriented knowledge-based system for transformer design

Encore: an object-oriented knowledge-based system for transformer design

Encore: an object-oriented knowledge-based system for transformer design

The design of electronic power transformers is an activity that requires the application of well-established algorithms from electromagnetic theory and heuristic, judgmental techniques derived from experience in the design and manufacturing of these devices. This paper describes an object-oriented knowledge-based system, Encore, that was developed at Houston Downhole Sensors (a division of Schlumberger Well Services). Encore combines object-oriented, rule-based, and procedural programming techniques to design 60 Hz power transformers. The system uses a heuristic search strategy to generate design alternatives, and then selects the “best” design based on size and efficiency considerations The heuristics are represented and applied as rules; the electromagnetic components are modelled as frame-like objects. The object-oriented nature of this system facilitated enhancements; by specializing some of the objects comprising a power transformer, a power inductor model was quickly developed. Encore reduces design time from a couple of days to less than an hour; it is being used to design the transformers and inductors of power supplies in new Schlumberger well-logging tools. The system was implemented on a Xerox interlisp Workstation using an object-oriented environment called STROBE.