Organizing the description of a relational data base

The design and implementation of the data structures used within a software system such as a compiler, an operating system or a data base management system are fundamental to the development of that system. Unfortunately, there are very few standard techniques for designing such data structures and for structuring the software used to support them. This paper proposes that it is possible to use data base techniques to design and implement such data structures. For this reason, it describes a methodology which is used to design large relational data bases, and then demonstrates how the methodology was modified and used to design the internal data structures of a relational data base management system. This paper concludes that this approach produces data structures which are better understood and easier to modify than those resulting from an ad-hoc approach.     

DML触发器实现数据完整性的应用研究

数据完整性是确保数据库数据安全的重要研究内容。通过DML触发器技术实现数据完整性控制,可有效防止由于对数据进行频繁的更新操作从而导致数据丢失或无效扩散。该文通过论述DML触发器的实现机制,并结合具体的开发实例,分析DML触发器在强制数据参照完整性、级联更新与删除、实现用户定义业务规则、更新不可更新视图等方面的应用基本步骤及设计技巧,反映了触发器应用在提高系统性能、简化数据库操作、维护数据完整性、有效性、增强数据库安全性、提高开发效率等方面的强大功能。     

DMX在货运代理海运数据挖掘中的应用

对数据挖掘语言（Data Mining Language,DML）和行业标准的研究,是数据挖掘领域的重要方向。在分析现有数据挖掘技术的基础上,对DMX进行讨论,提出了物流挖掘方案,并给出了在SSAS 2005中基于DMX的物流数据挖掘应用实例,很好地运用于货代海运业务中,证明是可行的。     

Foundations of a functional approach to knowledge representation

We present a new approach to knowledge representation where knowledge bases are characterized not in terms of the structures they use to represent knowledge, but functionally, in terms of what they can be asked or told about some domain. Starting with a representation system that can be asked questions and told facts in a full first-order logical language, we then define ask- and tell-operations over an extended language that can refer not only to the domain but to what the knowledge base knows about that domain. The major technical result is that the resulting knowledge, which now includes auto-epistemic aspects, can still be represented symbolically in first-order terms. We also consider extensions to the framework such as defaults and definitional facilities. The overall result is a formal foundation for knowledge representation which, in accordance with current principles of software design, cleanly separates functionality from implementation structure.     

Automatic model building and solving for optimization problems

Automatic modelling is one of the key topics in model base management in DSS. We consider the design and implementation of a system which automatically specifies an optimization model from an abstract form with a given set of data specified by a user and solves it by calling an appropriate solver. We implement our idea as a prototype in Prolog and illustrate its validity by simple examples.     

Micro MUMPS: An interactive database language for micro-computers

A simple interactive language named Micro MUMPS has been implemented on a microcomputer system. Its powerful facilities for data base manipulation and character handling make programming easy for end users who are unfamiliar with computers. Micro MUMPS is a practical subset of the language MUMPS which has been implemented on many minicomputers, and it also has some additional capabilities indispensable to micro-computer applications. A modified prefix B-tree is used in Micro MUMPS database and its organization can be changed according to the requirements of space and time efficiency. The design criteria of Micro MUMPS and micro-computer based implementation techniques are discussed in this paper.     

Object-oriented implementation issues in an experimental CAD system

This case study of object-oriented program design illustrates two limitations of object-oriented programming languages. Existing object-oriented languages do not have good facilities to support two key program design problems: the definition of composite objects, or data structures that include sets of related subobjects; and the specification and run-time management of temporary data structures required to implement efficient algorithms. Both composite objects and temporary data structures are important to the construction of a wide variety of programs. We use the design and implementation of an interactive computer-aided design system to describe how the limitations of present object-oriented languages complicate the design of composite objects and temporary data structures.     

TGMS: An object-oriented system for programming geometry

TGMS (tiered geometric modelling system) is an experimental system intended to reduce the difficulty and cost of developing new solid modelling applications while preserving investment in an existing, time-tested, solid modeller. The application developer writes programs in the TGMS language, which consists of a base language augmented by data types (classes) for geometry. The base programming language is AML/X, an object-oriented language intended for use in design and manufacturing applications. Solid modelling is done using an interface to GDP (geometric design processor), an existing, production-quality solid modelling system. TGMS shows how a system written in a non-object-oriented language can be used as a base for an object-oriented application programming environment. This paper presents the design of TGMS and discusses important aspects of its implementation. The TGMS language defines classes and methods that provide an interface to functions and data represented in a non-object-oriented language. To implement TGMS, issues related to communication, storage management and consistency were addressed. These, and other, implementation issues are discussed. The paper includes sample programs and a summary of feedback from TGMS users. It concludes that the use of object-oriented programming for geometry has many benefits, and that an object-oriented system can be built on top of a non-object-oriented system at less cost than building the equivalent object-oriented system from scratch.     

PostgreSQL数据库运行状态数据的统计收集机制分析

对象关系数据库是新一代的数据库管理系统,它将关系数据库系统与面向对象数据库系统两方面的特征相结合,不仅能很好地支持对象管理和规则管理,而且能更好地支持原有的关系数据管理.要维护一个对象关系数据库管理系统长期正常有效地运行,其中一个不可忽略的机制就是数据库的清理机制.PostgreSQL是一个面向公众的、开放源代码的对象关系数据库管理系统,受到了人们的普遍认可和欢迎.对该系统数据清理机制的一个重要组成部分--数据库运行状态的数据统计收集机制进行了全面分析,给出了统计收集信息的种类、主要函数、数据结构和实现算法,这将有助于维护和完善该数据库系统.     

A portable high-level database debugger and software performance monitor

The package DBDEBUG assits the users of CODASYL (network) database management systems in two ways. It can be used by applications programmers to debug their programs, and by the database administrator to monitor the performance of the database. The user may select the sections (or even individual statements) of his program to be traced and/or monitored. He may list the specific records and items he wishes to be investigated; he may also restrict tracing and monitoring to only certain DML verbs. The user's database schema and subschema are submitted to processors which generate a data dictionary. This data dictionary is then used by DBDEBUG in modifying the user's DML source code in order to obtain the specified tracing or performance statistics. The output is high-level in that it reflects the high-level language (DML COBOL) in which the user's source code was written. The package is designed to be portable. All but one of its components are written in standard Pascal or ANSI COBOL; assembler code is restricted to a ten-line subroutine which obtains L/O and CPU times from the operating system.     

On distributing JASMIN's optimistic multiversioning page manager

JASMIN is a functionally distributed database system running on multiple microcomputers that communicate with each other by message passing. The software modules in JASMIN can be cloned and distributed across computer boundaries. One important module is the intelligent store, a page manager that includes transaction-management facilities. It provides an optimistic, multiversioning concurrency control scheme. This scheme allows read-only transactions to run almost without conflict checking; this is important in some real-time database applications like telephone switching and routing services. The initial implementation of the intelligent store deals with centralized database only. Experiences in modifying the JASMIN intelligent store module to handle distributed databases are described. Design principles and system implementation techniques in the following areas are explored; process structure, data structures and synchronization on data structures. The process structure is aimed to provide high throughput and the data structures are designed to facilitate fast response time     

一种设施管理平台：FMS*

分析了AM/FM/GIS 系统所管理的设施对象的特征,设计了一种构建于通用GIS (Geographic Information System)基础之上的电信设施管理平台：FMS（Facilities Management System）, 对该设施管理平台的总体结构和特点作了阐述,对实现该平台的关键技术如规则库、设施对象的访问、图形接口的实现作了较为全面的说明。     

高校场馆使用数据管理系统的开发

高校场馆是学校文娱活动的重要场所,如何在数据统计管理上提炼出有价值的信息以提高场馆的使用效率和效益,达到学术与娱乐的和谐,是目前高校场馆管理者需要思考和探索的问题。运用桌面数据库管理系统Access开发的一个简单实用的高校场馆数据管理系统,实现了高效的数据查询及统计之目的。对于提高办公效率,提升管理水平有着较大的促进作用。     

基于MySQL 的可定制强制访问控制的研究与实现*

结合MySQL数据库系统,通过在其源代码中增加安全策略函数、修改原有数据字典、扩展SQL 语句以及建立安全策略统一管理平台的方法,实现了可定制强制访问控制机制.所实现的安全数据库原型系统使数据库安全管理员可以根据应用领域不同的安全需求灵活定义标签结构和访问规则,为增强安全数据库产品可用性、灵活性提供了一种新思路.     

ADOME: an advanced object modeling environment

ADOME, which stands for ADvanced Object Modeling Environment, is an approach to integrating data and knowledge management based on object oriented technology. Next generation information systems will require more flexible data modeling capabilities than those provided by current object oriented DBMSs. In particular, integration of data and knowledge management capabilities will become increasingly important. In this context, ADOME provides versatile role facilities that serve as “dynamic binders” between data objects and production rules, thereby facilitating flexible data and knowledge management integration. A prototype that implements this mechanism and the associated operators has been constructed on top of a commercial object oriented DBMS and a rule base system     

Diagnosis of feedwater heater performance degradation using fuzzy inference system

Power generation facilities cannot avoid performance degradation caused by severe operating conditions such as high temperature and high pressure, as well as the aging of facilities. Since the performance degradation of facilities can inflict economic on power generation plants, a systematic method is required to accurately diagnose the conditions of the facilities.This paper introduces the fuzzy inference system, which applies fuzzy theory in order to diagnose performance degradation in feedwater heaters among power generation facilities. The reason for selecting only feedwater heaters as the object of analysis is that it plays an important role in the performance degradation of power generation plants, which have recently been reported with failures. In addition, feedwater heaters have the advantage of using many data types that can be used in fuzzy inference because of low measurement limits compared to other facilities. Fuzzy inference systems consists of fuzzy sets and rules with linguistic variables based on expert knowledge, experience and simulation results to efficiently handle various uncertainties of the target facility. We proposed a method for establishing a more elaborate system. According to the experimental results, inference can be made with consideration on uncertainties by quantifying the target based on fuzzy theory. Based on this study, implementation of a fuzzy inference system for diagnosis of feedwater heater performance degradation is expected to contribute to the efficient management of power generation plants.     

电子CAD框架系统的长事务处理和网络版本管理

用面向对象方法管理框架系统中的工程和设计数据已成为大多数人的共识．本文对该系统中的Ｓｅｒｖｅｒ／Ｃｌｉｅｎｔ结构和并发控制、长事务管理、网络上的对象版本管理等进行了论述，提出了想法和实现．该系统已应用到电子ＣＡＤ框架系统中．     

基于XML数据源的监控软件实现

首先介绍了通信设备的监控软件,分析了其对外部数据库管理系统的依赖性,在此基础上提出了一种基于XML数据源的监控软件实现方法,并具体应用于基站拉远系统的监控软件OMT中.应用表明,软件能实现异构数据源的集成,消除了对数据库的依赖,数据处理速度高、运行稳定.详细阐述了该方法实现中的关键技术:数据源适配器和链表数据集.     

图形矢量技术在油田集输生产中应用的研究

从实现各种设备图层、设计生产进度和油气产品的处理以及为决策者及时提供第一手的数据三个方面，研究了图形矢量技术在油田集输生产管理系统中所起的重要作用．介绍了MapInfo的矢量化图形管理功能，列举了开发油田集输生产管理系统的一些经验．