演绎数据库中完整性约束视图表示和生成算法

在演绎数据库系统中,一般将完整性约束条件和IDB规则分别表示和存储。文章基于笔者自行设计的SD-DDBS系统的IDB规则视图表示方法,给出了一个生成算法,将完整性约束条件表示成视图形式,克服了传统方法中存储开销大,演绎查询实现复杂的缺点,有效地提高了演绎查询的执行效率。     

多媒体智能数据库系统MIDS／BUAA的总体设计

1.引言近二十年内,传统数据库(特别是RDB)技术获得了极大发展和广泛应用。但是,自八十年代以来,随着硬件造价的持续下降,人们对数据库提出了更多和更高的需(要)求,促     

数据库更新研究现状综述

一、引言一个数据库通常包括两个部分:数据资源和推导规则。数据资源是指存储在数据库中的事实。例如在一个家庭关系数据库中,Jonsson是Pater的父亲father(Jonsson,Peter),Mary是Peter的母亲mother(Mary,Peter)是数据资源。在计算机理论科学中又把数据库的这一部分称为外延数据库(EDB)。推导规则则是用户为数据演算定义的一种规则,或者也可以理解为数据之间的一种关系。例如祖父规则grandfather(X,Y)←father(X,Z),father(Z,Y),它规定若X为Z     

日新月异的数据库研究领域--数据库技术的回顾与展望

本文回顾十年来数据库技术的进展和主要成就，包括面向对象的和对象关系的数据库系统、多媒体数据的支持、并行数据库、web数据集成与检索、三级存储器技术、数据仓库、数据挖掘、数据可视化技术。本文还讨论了影响数据库研究的三个重要趋势，即Internet/Web技术、程序逻辑和数据的统一管理技术、迅速发展的计算机硬件技术。最后，本文探讨了嵌入式数据库系统、未来的联邦数据库系统、未来数据库系统的体系结构、程序逻辑和数据统一管理技术、结构化和半结构化数据的集成技术等几个主要数据库研究新方向。     

Design and implementation of a vehicle interface protocol using an IEEE 1394 network

A wide variety of in-vehicle devices such as camera sensors, navigation systems, telematics and communication equipments have been incorporated into a vehicle to realize Intelligent Transport Systems (ITS) applications. Because an efficient standardized network is required, ITS Data Bus (IDB) has been discussed to carry high-speed multimedia data for audio, video and other real-time ITS applications. For connecting devices in a standardized manner, the IDB network has architecture with a gateway called vehicle interface which is located between automaker’s proprietary network and the standardized IDB network. IEEE 1394 (also known as iLink or FireWire), which can transport multimedia data for consumer electronics, is a good candidate for IDB network. In this paper, we analyze the issues for existing AV/C protocol (application layer protocol over IEEE 1394) to comprise the IDB network. In addition, we designed and implemented the vehicle interface protocol as a higher layer of IEEE 1394 to address the AV/C protocol issues for realizing the whole IDB network architecture.     

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．     

基于SQL Server的演绎规则处理器

设计并实现了一种基于SQLServer的演绎规则处理器,其主要功能是把演绎规则转换为含有SQL语句的过程代码,利用该处理器用户可用一阶逻辑谓词定义和查询IDB关系。     

拓广的右线性递归变换算法及其正确性

本文给出拓广的右线性递归变换算法并证明其正确性.拓广的右线性递归中可以包含一个或多个IDB谓词,它是右线性递归的一般化.和右线性递归计算算法一样,本文提供的算法遵循魔集的模式:首先改写规则,然后用半扑质的自底向上算法计算新规则.算法的有效性通过减少递归谓词的元数实现.     

用K-D树实现对双模态多媒体数据库的有效查询

论文提出了一种用k-d树来查询双模态视觉听觉语音识别数据库的方法。这种方法揉合了查询地理信息系统的多维数据库和空间数据库的方法,结合双模态视觉听觉语音数据库自身的特点提出了在数据库中插入、查询和删除记录的算法。最后还对把查询多维数据的方法应用在双模态语音识别数据库领域进行了展望。     

拓广的左线性递仅变换算法及其正确性

本文给出拓广的左线性递归变换算法并证明其正确性．拓广的左线性递归中可以包含一个或多个ＩＤＢ谓词，它是左线性递归的一般化．和左线性递归计算算法一样，本文提供的算法遵循魔集的模式：首先改写规则，然后用半扑质的自底向上算法计算新规则．算法的有效性也在本文作简略讨论．     

Database design practices for inverted files

Database research literature has proposed many procedures, both manual and automated, for database design; selection of secondary indexes for inverted file type database management systems (DBMS) has been repeatedly addressed. The empirical study reported here indicates that practical inverted file design has been relatively unaffected by this research.This paper characterizes the actual database design process used at inverted file DBMS installations along such dimension as: types of secondary keys constructed, the individuals who make index design decisions, the decisions that are changed (and when) after the initial database implementation, the factors that are considered in indexing decisions, and the literature which is used in the process. The study shows that key selection (as one example of a design decision) is addressed by ad hoc procedures and well conceived procedures are not used. Further, the results indicate that database design is dominated by users and systems analysts, indexes are frequently changed and a wide range of database performance and convenience factors are influential in practice. The paper concludes with some recommendations for database design support tools.     

Use of the SQL and RDA standards in data management

This paper discusses how existing and proposed Database Language SQL and Remote Database Access (RDA) standards can fulfill critical operational requirements for data management. SQL and RDA are but two components of a family of data management standards needed to meet requirements for emerging distributed processing systems. Requirements for needed capabilities such as object-oriented database, distributed database, and database export/import are discussed.     

单一式和客户／服务器数据库系统：测试及分析

1.引言当前的数据库系统按其体系结构可分为两大类:一是单一式体系结构,如FOXBASE、FOXpRO、CLIPPER、PARAI洲〕X等。这一类系统大多实现在PC机上,其特点是整个数据系统实现为单个进程(在「X)S下可视为一个可执行文件)     

Designing deductive databases

We consider the problem of designing schemas for deductive databases. The design problem is to construct a database schema that supports, at minimal expected cost, a given set of database transactions. Our results include a formal definition of both a deductive database schema and a schema transformation. A schema transformation is used in the design process to transform one schema into another, with the goal of reducing the expected database costs. Our design methodology defines the concept of a schema transformation within the context of the clause-based deductive database model. The IDB of the schema that results from the design process includes clauses sufficient for a theorem prover to map queries stated against the original schema into queries against the (more cost effective) resulting schema. This allows users to interact exclusively with the initial schema, while the schema that results from the design process specifies the actual structure of the implemented database. In other words, the initial schema serves as the logical schema for the database, and the result of the design process serves as its physical schema.     

Modeling of closed-loop voltage-mode controlled interleaved dual boost converter

An extensive small-signal analysis of a voltage-mode controlled interleaved dual boost (IDB) converter operating in continuous current mode based on signal flow graph approach is proposed. Small-signal flow graph is developed, from which open-loop small-signal transfer functions are derived using well known Mason's gain formula. Closed-loop small-signal input-to-output, control-to-output transfer functions are also derived and frequency response characteristics are determined at different duty ratios. Voltage-mode compensator designed using K-factor approach is used for closed-loop operation of IDB converter. Load voltage regulation against supply voltage and load disturbances are demonstrated through experimental results.     

基于对象形状的图象查询技术

基于图象内容的查询是根据图象实体(或区域)的颜色、形状、纹理、空间关系等特征属性来查询图象.它把图象处理、图象识别、图象数据库3个领域的技术成果结合起来,是一个有前途的发展方向.本文所作的工作是研究和实现根据图象实体(或区域)的形状来查询图象,内容包括：(1) 人对于形状的认知过程；(2) 表征形状的特征量集合；(3) 一种快速有效的图象匹配算法；(4) 原型系统Photo Engine.     

Four reference architectures for distributed database management systems

Five requirements for a centralized database management system and five additional requirements for a distributed database management system suggest definitions of software processors and schemas. These software processors and schemas can be organized into four reference architectures for distributed database management systems which permit comparisons of their advantages and disadvantages.     

Inductive database languages: requirements and examples

Inductive databases (IDBs) represent a database perspective on Knowledge discovery in databases (KDD). In an IDB, the KDD application can express both queries capable of accessing and manipulating data, and queries capable of generating, manipulating, and applying patterns allowing to formalize the notion of mining process. The feature that makes them different from other data mining applications is exactly the idea of looking at the support for knowledge discovery as an extension of the query process. This paper draws a list of desirable properties to be taken into account in the definition of an IDB framework. They involve several dimensions, such as the expressiveness of the language in representing data and models, the closure principle, the capability to provide a support for an efficient algorithm programming. These requirements are a basis for a comparative study that highlights strengths and weaknesses of existing IDB approaches. The paper focuses on the SQL-based ATLaS language/system, on the logic-based LDL++{\mathcal{LDL}++} language/system, and on the XML-based KDDML language/system.     

基于SQL Server数据库和C++实现专家系统外壳

本文详细介绍了正向推理的基本原理及算法,在SQL Server数据库中创建知识库和全局数据库,及在Windows环境下用SQL Server数据库和C 实现专家系统外壳。只要在SQL Server数据库中建立不同的知识库便可以生成不同的专家系统。