KBASE－P知识库系统的设计与实现

当前的实用知识库系统研究是将知识库查询语言嵌入到一个过程语言中．ＫＢＡＳＥ－Ｐ是一个通用的知识库程序设计语言．ＫＢＡＳＥ－Ｐ以ＫＢＡＳＥ作为查询语言，以ＦＤ－ＰＲＯＬＯＧ（我们开发的一个ＰＲＯＬＯＧ扩充）为过程性的宿主语言执行１／Ｏ和ＤＢ更新操作（用扩充的内部谓词）．由于良好的设计和实现，查询语言与宿主语言之间的阻抗不匹配问题相对较小．因而，ＫＢＡＳＥ－Ｐ是一个比较实用的知识库程序设计语言．ＫＢＡＳＥ－Ｐ系统支持逻辑程序设计语言（ＫＢＡＳＥ－Ｐ语言）的程序开发，提供了文本编辑、文件管理、谓词管理、事实操作、Ｄａｔａｌｏｇ查询、ＳＱＬ查询等功能．本文详细介绍了ＫＢＡＳＥ－Ｐ系统的设计和实现．     

DATALOG与关系代数

本文旨在通过描述DATALOG和关系代数的概念，以及DATALOG与关系代数的区别，经过从关系代数到逻辑规则和从逻辑到关系的论述，并比较DATALOG和关系代数，说明DATALOG是一种基于逻辑的数据模型，是PROLOG语言的数据库版本，关系代数是过程化的语言，关系代数表达式与安全、非递归、带有非操作的DATALOG程序的表达能力是相同的。     

具有面向对象特征的知识库系统

本文讨论了具有面向对象特征的知识库系统KBASE~ 的数据模型、语言及实现。KBASE~ 的数据模型可以方便地支持对象标识、类层次、多继承等面向对象概念。描述性查询语言KBL是DATALOG针对于非一范式关系模型的扩充。本文重构了KBL的语义理论框架,提出了通过计算相关类的下确界来解决属性继承中的冲突问题,通过在KBL程序中添加规则来实现实例继承的方案,本文说明了KBL程序可以转换成语义等价的DATALOG程序,描述了这种转换的基本思想,探索了知识库和面向对象数据库有机结合的可行途径。     

An operational formal definition of PROLOG: a specification method and its application

We present in this paper a logic programming specification language and its application to the formal specification of PROLOG dialects (Marseille-Edinburgh like dialect or parallel logic programs). In particular it is used in the standardization work of PROLOG. The specification language is based on normal clauses (definite clauses with possibly negative literals in the body) whose semantics is the set of the (generalized) proof-trees. We restrict the specification language to stratified programs and ground proof-trees such that its semantics fits with most of the usual known semantics in logic programming. The specification language is fully declarative in the sense that it is written in a pure logical stule. It is relatively easy to deduce an executable specification from a specification written in such a language. Part of the specification are the associated comments and a methodology has been developed to write these. Without the comments a formal specification cannot be understood; they are partly formal and serve only to help to understand the axioms. They are a natural language form of formal statements relative to the correctness and the completeness of the axioms with regards to some intended meaning. We show in this paper how this specification language can be used to specify dialects of PROLOG. The presented example is just a sample of PROLOG but fully developed here. The specification language has already been used for real dialects as PARLOG and standard PROLOG. This specification method is also interesting because it illustrates the power of logic programming to make specifications. It seems to us that logic programming is generally considered as “impure” executable specification. Our purpose is to show that logic programming may also be used as a perhaps low level but full specification language.     

通用PRIP程序设计语言EPPPI的设计

本文介绍了一种同时具有PASCAI和PROLOG语言特点的通用的模式识别和图象处理(PRIP)程序设计语言EPPPL,相对于PASCAL,EPPPI包含了抽象级更高的数据类型和相应的公共操作.因而该语言具有比PASCAL更强的描述能力,使在科学计算程序设计时有更高的效率.文中论证了在EPPPI中引入PROLOG机制的可行性.由于在EPPPI中包含了PROLOG的机制,使该语言适用于人工智能程序设计,并具有陈述式特点,因而使它的编程效率更进一步提高.     

知识库系统KBASE＋的数据模型,语言及实现

本文讨论具有面向对象特征的知识库系统ＫＢＡＳＥ＋的数据模型，语言及实现，ＫＢＡＳＥ＋的数据模型可以方便地支持对象标识，类层次，多继承等面向对象概念。描述性查询语言ＫＢＬ是扩充的ＤＡＴＡＬＯＧ。本文重构了ＫＢＬ语义理论框架，提出了解决属性继承和实例继承的方案，说明了ＫＢＬ程序可以转换成语义等价的ＤＡＴＡＬＯＧ程序。     

Engineering information integration using object‐oriented mediator technology

The mechanical product development process uses many different software systems to virtually simulate the behaviour of a design. The present work deals with flexible and efficient integration using object‐oriented mediator technology that provides transparent access to distributed engineering systems. The use of mediator technology is investigated for semi‐automatically integrating engineering information resident in computer aided design systems with a Common Object Request Broker Architecture based application programming interface. The purpose is to provide engineering analysis applications access to computer aided design system information and computational methods through a declarative query language. We conclude that the use of a declarative query language for developing engineering applications shows great potential in terms of flexibility, development productivity, performance, and ease of use, compared with using a procedural programming language. The work also shows new use of mediator technology, declarative queries, and active rules within engineering information integration that traditionally is accomplished using procedural programming. Copyright © 2004 John Wiley & Sons, Ltd.     

智能程序设计语言VISUAL PROLOG 编程解析

VISUAL PROLOG具有很强的逻辑推理能力,且易于编程,操作界面友好,近年来得到程序设计行业的广泛 关注。本文对VISUAL PROLOG程序设计语言的主要特征进行概述,在此基础上,对基于VISUAL PROLOG语言的程序编 程展开较为深入的探究。     

ON TEMPORAL DEDUCTIVE DATABASES

This article introduces a temporal deductive database system featuring a logic programming language and an algebraic front-end. The language, called Temporal DATALOG, is an extension of DATALOG based on a linear-time temporal logic in which the flow of time is modeled by the set of natural numbers. Programs of Temporal DATALOG are considered as temporal deductive databases, specifying temporal relationships among data and providing base relations to the algebraic front-end. The minimum model of a given Temporal DATALOG program is regarded as the temporal database the program models intensionally. The algebraic front-end, called TRA, is a point-wise extension of the relational algebra upon the set of natural numbers. When needed during the evaluation of TRA expressions, slices of temporal relations over intervals can be retrieved from a given temporal deductive database by bottom-up evaluation strategies.
A modular extension of Temporal DATALOG is also proposed, through which temporal relations created during the evaluation of TRA expressions may be fed back to the deductive part for further manipulation. Modules therefore enable the algebra to have full access to the deductive capabilities of Temporal DATALOG and to extend it with nonstandard algebraic operators. This article also shows that the temporal operators of TRA can be simulated in Temporal DATALOG by program clauses.     

Default logic as a query language

Research in nonmonotonic reasoning has focused largely on the idea of representing knowledge about the world via rules that are generally true but can be defeated. Even if relational databases are nowadays the main tool for storing very large sets of data, the approach of using nonmonotonic AI formalisms as relational database query languages has been investigated to a much smaller extent. In this work, we propose a novel application of Reiter's default logic by introducing a default query language (DQL) for finite relational databases, which is based on default rules. The main result of this paper is that DQL is as expressive as SO_∃∀ the existential-universal fragment of second-order logic. This result is not only of theoretical importance: We exhibit queries-which are useful in practice-that can be expressed with DQL and cannot with other query languages based on nonmonotonic logics such as DATALOG with negation under the stable model semantics. In particular, we show that DQL is well-suited for diagnostic reasoning     

Well-definedness and semantic type-checking for the nested relational calculus

The well-definedness problem for a programming language consists of checking, given an expression and an input type, whether the semantics of the expression is defined for all inputs adhering to the input type. A related problem is the semantic type-checking problem which consists of checking, given an expression, an input type, and an output type whether the expression always returns outputs adhering to the output type on inputs adhering to the input type. Both problems are undecidable for general-purpose programming languages. In this paper we study these problems for the Nested Relational Calculus, a specific-purpose database query language. We also investigate how these problems behave in the presence of programming language features such as singleton coercion and type tests.     

Temporal logic CTL + PROLOG

The programming language TPL that is presented in this paper is a complete combination of PROLOG with a temporal language (the CTL language or other temporal languages expressed in atomata). It can be used to serve or reason along paths in a directed graph (a Kripke structure) which consists of many rule databases. At the end of the paper, a compiler (an algorithm) for reasoning language TPL has been supplied.     

An entity-relationship programming language

The syntax for an integrated E-R programming language is presented. The problems that arise when a query language is embedded in a general-purpose programming language are discussed. Other E-R languages are also discussed. The requirements for the language and a syntax for an E-R model in which entity sets are mutually disjoint and each entity type has a unique, perhaps multiattribute, key are presented. The syntax for a more limited model restricted to binary relationships between entity types and without attributes is presented. Some implementation considerations are discussed     

The Processing and Improvement of Multi-Statement Queries in Chiql

Chiql is a novel Chinese relational database query language for Chinese users.It supports procedural query style in which users can specify a complex database request in multiple simple statements.This facility renders Chiql simple-to-use and easy-to-remember.However,direct execution of multi-statemen Chiql rueries(i.e.statement by statement)is often inefficient as potential index-based operations(e.g.join) are by-passed.Furthermore,it often incurs additional database operations,such as scan and projection.To improve this situation,the SMA(Statement Merging Algorithm)is proposed.The goal of SMA is to merge as many dependent statments within Chiql query as possible to form a more efficient Chiql query.The ability in achieving improved effciency without sacrificing the simplicity of the language is the major advantage of this algorithm.     

Discovery of frequent DATALOG patterns

Discovery of frequent patterns has been studied in a variety of data mining settings. In its simplest form, known from association rule mining, the task is to discover all frequent itemsets, i.e., all combinations of items that are found in a sufficient number of examples. The fundamental task of association rule and frequent set discovery has been extended in various directions, allowing more useful patterns to be discovered with special purpose algorithms. We present WARMR, a general purpose inductive logic programming algorithm that addresses frequent query discovery: a very general DATALOG formulation of the frequent pattern discovery problem.The motivation for this novel approach is twofold. First, exploratory data mining is well supported: WARMR offers the flexibility required to experiment with standard and in particular novel settings not supported by special purpose algorithms. Also, application prototypes based on WARMR can be used as benchmarks in the comparison and evaluation of new special purpose algorithms. Second, the unified representation gives insight to the blurred picture of the frequent pattern discovery domain. Within the DATALOG formulation a number of dimensions appear that relink diverged settings.We demonstrate the frequent query approach and its use on two applications, one in alarm analysis, and one in a chemical toxicology domain.     

An order-sorted query system for sort, predicate, and meta-predicate hierarchies

This paper presents a decidable order-sorted query system for reasoning between ontologies and rules. We describe order-sorted logic programming with sort, predicate, and meta-predicate hierarchies (OSL_3h), which derives predicate and meta-predicate assertions. Meta-level predicates (predicates of predicates) are useful for representing relationships between predicate formulas, and further, they conceptually yield a hierarchy similar to the hierarchies of sorts and predicates. By extending the order-sorted Horn-clause calculus, we develop a query-answering system in OSL_3h that can answer queries such as atoms and meta-atoms generalized by containing predicate variables. We show that the expressive query-answering system computes every generalized query in single exponential time, that is, the complexity of our query system is equal to that of DATALOG.     

What is object-oriented programming?

The meaning of the term `object oriented' is examined in the context of the general-purpose programming language C++. This choice is made partly to introduce C++ and partly because C++ is one of the few languages that supports data abstraction, object-oriented programming, and traditional programming techniques. The support of programming paradigms by languages is discussed and four paradigms are examined: procedural, data hiding, data abstraction, and object-oriented programming. The support of the latter two by C++ is discussed in some detail     

File Structures, Program Structures, and Attributed Grammars

A language for defining sequential file structures, characterized as nested sequences of records having in common certain keys and types, is presented. "Input schemata" are defined as program skeletons that contain all the necessary control structure to process a specified file. A method for obtaining an input schema from the corresponding file structure definition is given. The method is based on attributed grammars, and has been implemented in the programming language PROLOG. This constitutes a formalization of some aspects of the data-directed program design method of Jackson and Warnier. Examples of applications of this method to business data processing problems such as file updating and report generation are given.     

A PROLOG APPROACH TO IMAGE SEGMENTATION

Segmentation is a main problem in computer vision. It attempts to supply primitives for higher-level processes of interpretation. A multithreshold approach has already given acceptable results. This paper presents a PROLOG implementation of a multithreshold system. The system uses the technique of recursive partition of two-dimensional images in quadrants to form maximal blocks; the data structure generated by this partition algorithm is known as a quadtree. The algorithms implemented concern image representation, connected regions, identification, and contour detection. The improvement of algorithms in a logic language rather than in a procedural one appeared to be of particular interest. The main reasons for this are implementation facility and the natural use of logic programming in the field of knowledge-based systems. In fact, a knowledge-based approach seems a reasonable solution to problems of assisted image understanding processes.