面向对象的专家系统及其在柔性制造系统调度决策中的应用

本文把面向对象的方法用于专家系统的设计。文中结合柔性制造系统调度决策系统的设计，讨论了面向对象的知识获取、面向对象的知识表示及面向对象的推理的实现。文中介绍了面向对象的专家系统的实现软件。给出了实验结果。     

模糊面向对象数据模型的描述逻辑表示与推理

通过分析描述逻辑与面向对象数据模型之间的关系,研究了基于描述逻辑的模糊面向对象数据(fuzzy object-oriented data,简称FOOD)模型的表示与推理.首先,进一步研究了FOOD模型,提出了FOOD模型的形式化定义和语义定义,以便更好地在FOOD模型与模糊描述逻辑之间建立对应关系;然后,针对FOOD模型的特点和推理需求,介绍了模糊描述逻辑f-ALCIQ.在此基础上,研究了基于f-ALCIQ的FOOD模型的表示与推理,包括:实现了从FOOD模型到f-ALCIQ知识库在结构层和实例层上的转化,即实现了从FOOD模型到f-ALCIQ TBox的转化,以及从FOOD模型相应的数据库实例到f-ALCIQ ABox的转化;进而,基于转化得到的f-ALCIQ知识库,研究了如何利用f-ALCIQ的推理机制对FOOD模型的推理问题(一致性、包含性和冗余性等)进行推理;最后,设计并实现了基于f-ALCIQ的模糊描述逻辑推理机(FRsQ推理机),实现了对FOOD模型和f-ALCIQ模糊概念知识的自动推理.     

A Model-Based Approach to Object-Oriented Software Metrics

The need to improve software productivity and software quality has put forward the research on software metrics technology and the development of software metrics tool to support related activities.To support object-oriented software metrics practice efectively,a model-absed approach to object-oriented software metrics is proposed in this paper.This approach guides the metrics users to adopt the quality metrics model to measure the object-oriented software products .The development of the model can be achieved by using a top-down approach.This approach explicitly proposes the conception of absolute normalization computation and relative normalization computation for a metrics model.Moreover,a generic software metrics tool-Jade Bird Object-Oriented Metrics Tool(JBOOMT)is designed to implement this approach.The parser-based approach adopted by the tool makes the information of the source program accurate and complete for measurement.It supports various customizable hierarchical metrics models and provides a flexible user interface for users to manipulate the models.It also supports absolute and relative normalization mechanisms in different situations.     

浅谈面向对象分析的基础教学

针对一个业务应用实例进行介绍,从而引入软件工程、面向对象分析的基本概念、优点和表示方法,并向读者展现如何在程序设计课程中开展面向对象分析与设计的基础教学。     

Building knowledge base management systems

Advanced applications in fields such as CAD, software engineering, real-time process control, corporate repositories and digital libraries require the construction, efficient access and management of large, shared knowledge bases. Such knowledge bases cannot be built using existing tools such as expert system shells, because these do not scale up, nor can they be built in terms of existing database technology, because such technology does not support the rich representational structure and inference mechanisms required for knowledge-based systems. This paper proposes a generic architecture for a knowledge base management system intended for such applications. The architecture assumes an object-oriented knowledge representation language with an assertional sublanguage used to express constraints and rules. It also provides for general-purpose deductive inference and special-purpose temporal reasoning. Results reported in the paper address several knowledge base management issues. For storage management, a new method is proposed for generating a logical schema for a given knowledge base. Query processing algorithms are offered for semantic and physical query optimization, along with an enhanced cost model for query cost estimation. On concurrency control, the paper describes a novel concurrency control policy which takes advantage of knowledge base structure and is shown to outperform two-phase locking for highly structured knowledge bases and update-intensive transactions. Finally, algorithms for compilation and efficient processing of constraints and rules during knowledge base operations are described. The paper describes original results, including novel data structures and algorithms, as well as preliminary performance evaluation data. Based on these results, we conclude that knowledge base management systems which can accommodate large knowledge bases are feasible. Edited by Gunter Schlageter and H.-J. Schek. Received May 19, 1994 / Revised May 26, 1995 / Accepted September 18, 1995     

Automated functional design of engineering systems

This paper presents a prototype intelligent system, the knowledge-based functional design automation system (KBFDA) for automating the functional design process of engineering products/systems. An integrated knowledge representation scheme combines rule-based and object-oriented representation methods to represent functions and function related design characteristics in an intelligent design environment. A knowledge-based functional reasoning strategy uses this representation to automatically generate physical behaviors from desired functions or behaviors. The required behaviors are then combined in different configurations to develop a set of potential concept variants that meet the functional requirements and functional constraints given in a design specification. Finally, the variants are ranked according to the degree to which they meet non-functional constraints. The variant with the lowest rank (score) is selected as the best solution. A case study design of a terminal insertion unit is presented to demonstrate the practicality of the proposed approach.     

An Object-Logic model for the representation and processing of design standards

There are two distinct categories of knowledge in a design standard: (1) knowledge of the organization of design objects and (2) knowledge of the methods used in reasoning about the design objects. The object-oriented paradigm lends itself naturally to representing the organizational aspect of the design standard. The logic programming paradigm, on the other hand, is well suited to implementing the reasoning mechanisms for design and conformance checking. The object-oriented and logic programming paradigms are combined to provide a unified Object-Logic model for the representation of design codes and the processing of design standards. By storing the design provisions in a knowledge base, the model is capable of performing conformance checking and component design. To evaluate the feasibility and practicality of this model, a prototype system, HyperLRFD++, has been implemented for parts of the American Institute of Steel Construction (AISC) Load and Resistance Factor Design (LRFD) specification and tested on sample problems.     

Knowledge acquisition and knowledge representation with class: the object-oriented paradigm

Knowledge acquisition and knowledge representation are the fundamental building blocks of knowledge-based systems (KBSs). How to efficiently elicit knowledge from experts and transform this elicited knowledge into a machine usable format is a significant and time consuming problem for KBS developers. Object-orientation provides several solutions to persistent knowledge acquisition and knowledge representation problems including transportability, knowledge reuse, and knowledge growth. An automated graphical knowledge acquisition tool is presented, based upon object-oriented principles. The object-oriented graphical interface provides a modeling platform that is easily understood by experts and knowledge engineers. The object-oriented base for the automated KA tool provides a representation independent methodology that can easily be mapped into any other object-oriented expert system or other object-oriented intelligent tools.     

Knowledge representation-oriented nets for discrete event systemapplications

This paper presents knowledge representation-oriented nets (KRON), a knowledge representation schema for discrete event systems (DES). KRON enables the representation and use of a variety of knowledge about a DES static structure and its dynamic states and behavior. It is based on the integration of high-level Petri nets with frame-based representation techniques and follows the object-oriented paradigm. The main objective considered in its definition is to obtain a comprehensive and powerful representation model for data and control of DES. The use of the DES behavioral knowledge is governed by a control mechanism stored in a separate inference engine. KRON provides an efficient execution mechanism to make the models evolve. This is an adaptation of the RETE matching algorithm in order to deal with the features provided by high-level Petri nets and it takes advantage of its integration with a frame/object-oriented representation schema, Moreover, KRON facilitates dealing with decision points in the execution of nondeterministic models. A prototype of a simulation tool with graphical display and animation facilities has been implemented for KRON and it has been used in several case studies in the manufacturing systems domain     

ICAD中概念设计的物元系统与或网模型及相关可拓推理

基于物元动态系统理论提出利于计算机表示产品概念设计的物元系统与或网模型和相关可拓推理。论述了产品概念没计的物元系统与或网模型除具有面向对象的知识表示方法的表示能力之外，还具有较强的概念设计、创新设计过程的表示能力。预计基于这些模型开发的ICAD系统，能支持产品概念设计。     

EFDEX: A Knowledge-Based Expert System for Functional Design of Engineering Systems

This paper presents a knowledge-based system, ‘EFDEX’, the Engineering Functional Design Expert, which was developed using an expert system shell, CLIPS 6.1, to perform intelligent functional design of engineering systems. On the basis of a flexible, causal and hierarchical functional modeling framework, we propose a knowledge-based functional reasoning methodology. By using this intelligent functional reasoning strategy, physical behavior can be reasoned out from a desired function or desired behavior, and inter-connection of these behaviors is possible when there is compatibility between the functional output of one and the corresponding functional requirement (e.g. driving input) of the next one. In addition, a complicated, desired function which cannot be matched with the functional output of any behavior after searching the object-oriented behavior base, will be automatically decomposed into less complex sub-functions by means of relevant function decomposition rules. An intelligent system for the functional design of an automatic assembly system provides an application of this intelligent design environment, and a demonstration of its methodology. In this paper, a knowledge-based functional representation scheme which integrates two popular AI representation techniques (object-oriented representation and rule-based representation) is also proposed as a prelude to a knowledge-based functional design system     

Developing maintainable expert systems using case-based reasoning

Abstract: Maintainability problems associated with traditional software systems are exacerbated in rule-based systems. The very nature of that approach — separation of control knowledge and data-driven execution — hampers maintenance. While there are widely accepted techniques for maintaining conventional software, the same is not true for rule-based systems. In most situations, both a knowledge engineer and a domain expert are necessary to update the rules of a rule-based system. This paper presents, first, an overview of the software engineering techniques and object-oriented methods used in maintaining rule-based systems. It then discusses alternate paradigms for expert system development. The benefits of using case-based reasoning (from the maintenance point of view) are illustrated through the implementation of a case-based scheduler. The main value of the scheduler is that its knowledge base can be modified by the expert without the assistance of a knowledge engineer. Since changes in application requirements can be given directly to the system by the expert, the effort of maintaining the knowledge base is greatly reduced.     

面向对象编程与定理证明相结合实现问题自动求解

本文针对一类智能决策支持系统中,基于模型行为仿真以实现解题过程自动化的需要,提出对模型对象行为的一阶谓词演算型表达和面向对象型模型处理过程的形式化体系。将问题自动求解过程转化为逻辑运算过程,通过归结反演求取问题的解。文中给出一个应用实例。     

Automating the product derivation process of multi-agent systems product lines

Agent-oriented software engineering and software product lines are two promising software engineering techniques. Recent research work has been exploring their integration, namely multi-agent systems product lines (MAS-PLs), to promote reuse and variability management in the context of complex software systems. However, current product derivation approaches do not provide specific mechanisms to deal with MAS-PLs. This is essential because they typically encompass several concerns (e.g., trust, coordination, transaction, state persistence) that are constructed on the basis of heterogeneous technologies (e.g., object-oriented frameworks and platforms). In this paper, we propose the use of multi-level models to support the configuration knowledge specification and automatic product derivation of MAS-PLs. Our approach provides an agent-specific architecture model that uses abstractions and instantiation rules that are relevant to this application domain. In order to evaluate the feasibility and effectiveness of the proposed approach, we have implemented it as an extension of an existing product derivation tool, called GenArch. The approach has also been evaluated through the automatic instantiation of two MAS-PLs, demonstrating its potential and benefits to product derivation and configuration knowledge specification.     

一种面向对象的专家系统设计方法

近年来,已经有不少面向对象技术运用于专家系统的研究。本文提出一种新的面向对象专家系统的设计方法。首先介绍系统总体结构,给出知识表示模型和推理机制,并且引入RMG的概念,进一步提出运用RMG完成推理过程的算法。最后把提出的方法应用于中西医结合糖尿病诊疗专家系统的开发。实践证明此方法是有效的。     

Object-oriented programming for engineering software development

The representation of engineering systems in a manner suitable for computer processing is an important aspect of software development for computer aided engineering. The process of abstraction is a well-known technique for developing data representations. Objects are a mechanism for representing data using abstraction, and object-oriented languages are languages for writing programs to manipulate objects. The paper shows through examples the advantages of object-oriented programming for developing engineering software. Mathematical graphs are used as an abstraction for two problems: (1) sorting activities in a schedule and (2) ordering nodes and elements in a finite element mesh. Classes of objects are developed for generic graphs, activity procedence graphs, and graphs of elements meshes. Object-oriented program development leads to modular programs and a substantial reuse of code for the two problems.     

Application of knowledge-based approaches in software architecture: A systematic mapping study

ContextKnowledge management technologies have been employed across software engineering activities for more than two decades. Knowledge-based approaches can be used to facilitate software architecting activities (e.g., architectural evaluation). However, there is no comprehensive understanding on how various knowledge-based approaches (e.g., knowledge reuse) are employed in software architecture.ObjectiveThis work aims to collect studies on the application of knowledge-based approaches in software architecture and make a classification and thematic analysis on these studies, in order to identify the gaps in the existing application of knowledge-based approaches to various architecting activities, and promising research directions.MethodA systematic mapping study is conducted for identifying and analyzing the application of knowledge-based approaches in software architecture, covering the papers from major databases, journals, conferences, and workshops, published between January 2000 and March 2011.ResultsFifty-five studies were selected and classified according to the architecting activities they contribute to and the knowledge-based approaches employed. Knowledge capture and representation (e.g., using an ontology to describe architectural elements and their relationships) is the most popular approach employed in architecting activities. Knowledge recovery (e.g., documenting past architectural design decisions) is an ignored approach that is seldom used in software architecture. Knowledge-based approaches are mostly used in architectural evaluation, while receive the least attention in architecture impact analysis and architectural implementation.ConclusionsThe study results show an increased interest in the application of knowledge-based approaches in software architecture in recent years. A number of knowledge-based approaches, including knowledge capture and representation, reuse, sharing, recovery, and reasoning, have been employed in a spectrum of architecting activities. Knowledge-based approaches have been applied to a wide range of application domains, among which “Embedded software” has received the most attention.     

Functional Knowledge Representation Based on Problem Reduction

This paper proposes an approach for functional knowledge representation based on problem reuction,which represents the organization of problem-solving activities in two levels:reduction and reasoning.The former makes the functional plans for problem-solving while the latter constructs functional units, called handlers,for executing subproblems designated by these plans.This approach emphasizes that the representation of domain knowledge should be closely combined with(rather than separated from)its use,therefore provides a set of reasoning-level primitives to construct handlers and formulate the control strategies for executing them,As reduction-level primitives,handlers are used to construct handler-associative networks,which become the executable representation of problem-reduction graphs,in order to realize the problem-solving methods suited to domain features.Besides,handlers and their control slots can be used to focus the attention of knowledge acquisition and reasoning control.