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1.
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I/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。KBA  相似文献   

2.
施伯乐  朱扬勇 《软件学报》1996,7(A00):544-550
KBASE-P是一个知识库程序设计语言,它以KBASE作为查询语言,以FD-PROLOG为过程性的宿主语言,二者具有要同的编程风范,都是Horn子句风范,并且系统对任何磁盘访问是以“每次一个集合”的方式进行,因此在KBASE-P中,查询语言与宿主语言之间的“阻抗不匹配”问题尽可能地减小了,KBASE-P以RDBMS来管理事实(包括中间求值结果)和规则,因此能够有效地管理大容量的数据,并且数据是可菜  相似文献   

3.
知识库系统KBASE+的数据模型,语言及实现   总被引:1,自引:0,他引:1  
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。  相似文献   

4.
解大型稀疏线性代数方程组的预条件Krylov子空间方法邓健新(中国科学院计算中心)PRECONDITIONINGKRYLOVSUBSPACEMETHODSFORLARGESPARSELINEARALGEBRAICSYSTEMS¥DengJian-xi...  相似文献   

5.
一类并行多步Runge-Kutta预校算法李寿佛,甘四清(湘潭大学数学系)ACLASSOFPARALLELMULTISTEPRUNGE-KUTTAPREDICTOR-CORRECTORALGORITHMS¥LiShou-fo;GanSi-qing(D...  相似文献   

6.
具有面向对象特征和知识库系统   总被引:1,自引:0,他引:1  
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^+的数据模型可可以方便地支持对象标识,类层次,多继承等面和对象概念。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DA  相似文献   

7.
两分块K-循环Toeplitz矩阵相乘的快速算法   总被引:5,自引:0,他引:5  
两分块K-循环Toeplitz矩阵相乘的快速算法余品能(南京工程兵工程学院)AFASTALGORITHMFORCOMPUTINGTHEPRODUCTSOFBLOCKK-CIRCULANTTOEPLITZMATRICES¥YuPinneng(Insti...  相似文献   

8.
SHAPEPRESERVINGINTERPOLATIONUSINGPIECEWISECUBICFangKui;TanJianrongSMOOTHSURFACEINTERPOLATIONOVERARBITRARYTRIANGULATIONSBYSUBD...  相似文献   

9.
任伟利 《计算机学报》1994,17(2):152-156
在专用网上实现的中西文兼容Videotex终端的设计任伟利(西安交通大学信息与控制工程系西安710049)DESIGNOFCOMPATIBLECHINESE-ENGLISHVIDEOTEXTERMINALBASEDONSPECIAL-PURPOSEN...  相似文献   

10.
安装ACTIVE PERL l由于 ULTIMATE BHLLETINBOARD MM.M*u CGI撰写的讨论区程序,因此如果要在WINDOWS环境下执行,就必须安装PERL执行程序。所以首先请到这里下载免费的ACTIVEPERL程序:HTTP://WWW.ACTIVESTATE.COM/DOWN-LOAD/ACTIVEPERL/WINDOWS/5.6/ACTIVEPERL-5.6.0.623-MSWIN32-X86-MULTI—THREAD.MSI。 下载完后,请直接执行ACTIVEPERL-5.…  相似文献   

11.
Since extending DATALOG to a general-purpose programming language seems very difficult,many projects have embedded a DATALOG-based query laguage into a procedural host language,such as CORAL,Glue-Nail,etc.Although DATALOG can be consideed as function-free PROLOG,they are very different in many aspects.For instance,DATALOG is declarative while PROLOG isn‘t,DATALOG takes “a-set-at-a-time” mode of evaluation but PROLOG takes “a-tuple-at-a-time”one,DATALOG is only a query language whereas PROLOG is a general-purpose programming language.It is thought that integrating DATALOG with PROLOG may take their advantages.KBASEP is such a language.It uses KBASE as the query language and PROLOG as its procedural host language,where KBASE is a ne extemsion of DATALOG with negation and function.This paper introduces the integration techniques used in KBASE-P system.  相似文献   

12.
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。  相似文献   

13.
The implementation of POSTGRES   总被引:5,自引:0,他引:5  
The design and implementation decisions made for the three-dimensional data manager POSTGRES are discussed. Attention is restricted to the DBMS backend functions. The POSTGRES data model and query language, the rules system, the storage system, the POSTGRES implementation and the current status and performance are discussed  相似文献   

14.
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.  相似文献   

15.
This paper introduces a heterogeneous distributed database system called LSZ system,where LSZ is an abbreviation of Li Shizhen,an ancient Chinese medical scientist.LSZ system adopts cluster as distributed database node(or site).Each cluster consists of one of several microcomputers and one server.Te paper describes its basic architecture and the prototype implementation,which includes query processing and optimization,transaction manager and data language translation.The system provides a uniform retrieve and update user interface through global relational data language GRDL.  相似文献   

16.
OSCAR查询优化器的设计与实现*   总被引:1,自引:0,他引:1  
查询优化是数据库管理系统的一个重要组成部分。首先介绍了查询优化在数据库设计中的重要作用,给出了OSCAR数据库系统的查询处理器工作步骤,然后主要讨论了OSCAR数据库系统查询优化器的设计和实现。在查询优化模块,介绍了查询优化预处理技术和子查询提升技术,接着详细讨论了存取路径的选择和路径代价的估算方法。最后对测试结果进行了分析,结果表明优化后的系统查询效率比原系统有了显著提高。  相似文献   

17.
We describe the Enosys XML integration platform, focusing on the query language, algebra, and architecture of its query processor. The platform enables the development of eBusiness applications in customer relationship management, e-commerce, supply chain management, and decision support. These applications often require that data be integrated dynamically from multiple information sources. The Enosys platform allows one to build (virtual and/or materialized) integrated XML views of multiple sources, using XML queries as view definitions. During run-time, the application issues XML queries against the views. Queries and views are translated into the XCQL algebra and are combined into a single algebra expression/plan. Query plan composition and query plan decomposition challenges are faced in this process. Finally, the query processor lazily evaluates the result, using an appropriate adaptation of relational database iterator models to XML. The paper describes the platform architecture and components, the supported XML query language and the query processor architecture. It focuses on the underlying XML query algebra, which differs from the algebras that have been considered by W3C in that it is particularly tuned to semistructured data and to optimization and efficient evaluation in a system that follows the conventional architecture of database systems.  相似文献   

18.
Users of electronic medical databases request pertinent information by recasting their clinical questions into a formal database query language. Because the query language is the user's only access to the data, the query language must be powerful enough to enable users to express their data requirements. However, a competing need is for the query language to be restrictive enough so that queries can have unambiguous semantics and the query processor can generate correct answers. We describe a query language, called TQuery , that was designed specifically to formulate database queries that are dependent on temporal and contextual relationships. TQuery specifications express contextual constraints without the need to explicitly reference calendar dates. TQuery is the database query language used to retrieve patient data from an object-oriented electronic patient medical-record system called the temporal network (TNET). TNET and TQuery were developed to support the real-time temporal reasoning and representation needs of a LISP workstation-based medical expert system.  相似文献   

19.
TIGUKAT: A uniform behavioral objectbase management system   总被引:1,自引:0,他引:1  
We describe the TIGUKAT objectbase management system, which is under development at the Laboratory for Database Systems Research at the University of Alberta. TIGUKAT has a novel object model, whose identifying characteristics include a purely behavioral semantics and a uniform approach to objects. Everything in the system, including types, classes, collections, behaviors, and functions, as well as meta-information, is a first-class object with well-defined behavior. In this way, the model abstracts everything, including traditional structural notions such as instance variables, method implementation, and schema definition, into a uniform semantics of behaviors on objects. Our emphasis in this article is on the object model, its implementation, the persistence model, and the query language. We also (briefly) present other database management functions that are under development such as the query optimizer, the version control system, and the transaction manager.Bell Northem Research  相似文献   

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