DOL: 一个演绎对象库语言

演绎对象数据库是对象数据模型和演绎数据库集合的产物.它集成演绎数据库的查询能力和对象数据库的强大建模能力.DOL(deductive object base language)是作者设计的一种演绎对象库语言,它支持类、类层次、继承、集合、部分集、方法及重载和否定.文章着重研究继承、重载和复杂结构化值的交互关系.定义了压缩操作子和重载操作子.基于这两个操作子,定义了与经典逻辑程序类似的直接后承操作子,并研究其不定点性质.     

演绎对象数据库中基于行为规则的继承方法

在演绎对象数据库的研究和发展过程中，仍有两个重要的问题未能很好的解决：非单调的多值结构和行为规则的继承；基于规则的行为的封装。针对前一个问题，文中提出了几种解决的方法。特别是提出了一种新的继承方法——行为继承的回退，以获得更多的信息。通过一个数据库实例以及对它的查询，进一步说明这些继承的思想。     

一个演绎对象数据库SD-DOOD的设计与实现

通过探寻面向对象数据库与知识库技术相结合的途径，研究演绎对象数据库系统实现的关键技术。以基于演绎数据库系统SD-DDBS，设计实现了一个演绎对象数据库系统原型SD-DOOD。系统支持类、类层次、对象、属性、方法、继承和封装等面向对象数据库系统的核心概念，支持演绎对象等演绎数据库的概念，提供了图形用户接口(GUI)，便于用户进行创建、查询等操作。     

利用绑定技术实现分布式继承

面向对象编程语言的继承机制实现了子类和父类间is-a的关系,子类对象成为一个有效的父类对象,具有了父类对象的功能,实现了继承和扩展父类的目的。但是继承难以在分布式环境中跨网络实现,难以实现异构的分布式对象间的继承,所以在借鉴已有绑定技术的基础上,文章将绑定应用到分布式对象之间,提出了一种新的分布式继承模型:利用分布式对象间的绑定来增强和扩展分布式对象的功能,从而达到一种分布式继承的效果。     

基于UML的数据库建模技术研究

论文主要探讨以UML对象类图作为数据库建模的方法：在UML的对象类中得到关系模式的键,把关联的多重性分配到关系模式中去,把泛化（继承）联系转换为关系模式,把行为（操作）转换为触发器和存储过程;从而将UML与关系数据库技术相结合,方便数据库的设计。     

演绎对象库语言DOL的求值技术

ＤＯＬ语言是文中设计的一个演绎对象库语言，通过引入重载操作子，处理继承与重载的关系，文中讨论ＤＯＬ语言的基于程序重写的求值技术，研究表明，由于ＤＯＬ引入对象角色概念，程序重写技术的简单性。     

基于Web的战略态势表现系统研究与实现

该文提出了一种基于Web的战略态势表现系统研究与实现思路。该思路强调三个方面：战略态势数据和表现方式的分离；访问效率高、扩展性强的态势数据库；数据读取和态势表现功能的模块化。按照这种思路，首先，分析系统基本工作原理和基本工作流程；其次，把要表现的态势元素封装成态势对象。并构造态势对象类和态势表现类；再次，采用面向对象的方法设计态势数据库；最后。以XML作为数据读取中间件。基于SVG技术和Web技术进行态势表现的设计与实现，并实现了态势表现的模块化。     

移动对象子轨迹段分割与聚类算法

将运动轨迹作为整体聚类会丢失相似子轨迹段,而相似子轨迹段在实际应用中用处很大,如天气预报、交通控制等。提出一种新方法T-CLUS进行轨迹聚类,先将长轨迹分割成许多较短的直子段,再产生子段的增广聚类顺序,最后根据可达性图识别子轨迹聚类结构,得到子轨迹运动模式。实验结果表明T-CLUS方法在从轨迹数据库中发现相似子轨迹上是可伸缩的和正确的。     

面向对象数据库中的模糊类层次建模

本文提出了一种建立面向对象数据库中模糊类层次模型的方法，利用属性与类的相关和对象与类间的语义距离与建立对象与类的关系；利用属性与类的相关和类与子类间的语义距离来建立类与子类的关系。同时，讨论了模糊类层次中多重继承的问题，这种模型扩充了现有的面向对象数据模型，并与其兼容。     

基于属性依赖关系和对象相关性的自然聚类算法

针对数据集中属性间存在依赖关系以及对象间存在相关性,定义了一种新的相似关系模型,该模型所描述的相似关系能够体现对象之间的自然相关性.在此基础上提出一种基于属性依赖关系和对象相关性的自然聚类算法,该聚类算法在不事先指定聚类数目的情况下,将所有相似性达到设定阈值的对象自然聚为一类;当调整相似性阈值时,该算法还可实现不同粒度的聚类.通过分别对数值型数据集和分类型数据集进行实验比较分析,结果表明这种自然聚类算法与其他聚类算法相比,能够真实反映数据间的相关性以及数据集的自然簇结构,同时可以发现任意形状的簇,有效地提高了聚类的精度和质量.     

事务逻辑对象库语言

对象封装了结构和行为.对象数据库为大规模复杂应用提供良好的建模方法和实现手段.对象与逻辑结合导致目前对演绎对象库的研究.然而,这些研究基本上针对对象的结构描述,而很少涉及到对象的动态行为的描述.该文重点研究对象的动态行为,分析对象特征：继承和重载对事务语义的影响,并设计了一个事务对象库语言TOL(transaction object base language).首先分析TOL中的基本更新活动的特征,然后研究其事务的模型论语义.TOL模型论语义基于通路结构.     

An Overview of the Rule-Based Object Language

This paper presents an overview of a novel strongly typed deductive object database language, called Rule-based Object Language, which is being developed at the University of Regina. Rule-based Object Language is a uniform language for defining, querying, and manipulating a database, which integrates important features of deductive databases and object databases. It supports object identity, complex objects, classes, class hierarchies, multiple inheritance with overriding and blocking, and schema definition. It also supports structured values such as functor objects and sets, treating them as first class citizens and providing powerful mechanisms for representing both partial and complete information about sets. Important integrity constraints such as domain, referential, functional dependency, multi-valued dependency, and cardinality are built-in in a uniform framework. Rule-based Object Language directly supports non-first normal form relations and is an extension of the pure valued-oriented deductive languages such as Datalog and LDL (without grouping) and subsumes them as special cases. It supports schema, object, fact and rule queries in a uniform framework. It also supports schema, fact and rule updates.     

工程数据库系统中的知识管理

本文提出了工程数据库系统中的知识管理的概念，将建立在符号对象模型基础之上的知识分为三类：工程策略的管理，存取控制和规划的管理，本文着重讨论了复杂对象推理的特点，建立了从符号对象标识符，型继承和语义关系等概念，支持集合和局部不一致数据的处理，能更好地满足工程应用的要求。     

演绎的面向对象数据库研究

文中从复杂对象逻辑语言，面向对象逻辑基础及面向对象数据库演量询语言等三个方面研究了一些典型的演绎面向对象数据库的成果，对它们进行了分析和比较，并就目前研究中一些重要的尚待解决的问题作了进一步讨论。     

An object deputy model for realization of flexible and powerful objectbases

In object-oriented databases, data and methods are combined by objects and their classes. Information redundancies are removed by the notions of class hierarchy and inheritance. This contributes the realization of high-performance systems. However, the flexibility of object structures still remains a problem due to its encapsulation feature. In this paper, we introduce an object deputy model which extends conventional object-oriented models with the concepts of deputy objects and deputy classes. A deputy object has its own identifier and may possess its own attributes and methods. It can also have attributes that are computed from values stored within its source object, and can be associated with methods generated from these of the source object. The inheritances are realized by switching operations, which make it possible to realize controllable, selective and dynamic inheritance structures. Schemata of deputy objects are defined by deputy classes which can be derived by an object deputy algebra. An object can have many deputy objects, and several objects can share a single deputy object. Thus, objects can be indirectly divided and combined through their deputy objects. We show that several difficult database problems, such as flexible views, objects with more than one role, object migration, and multiple inheritance become much easier in this model. The data-knowledge coordination model developed for the integration of distributed databases and knowledge-bases can also be realized easily by the object deputy model. Finally, we discuss several advanced database applications of this model, such as geographic databases, virtual office systems, and distant education systems.     

Copying Errors in Object-Oriented Design

This paper presents a solution to an integration problem arising when copying (reusing) software components developed for one domain into software structures in a similar domain. This particular problem has not been previously addressed in the design of object-oriented languages whose intent is to enhance software reuse and software integration. Object structures are directed graphs where edges are either inheritance or client- server associations, and nodes are abstract data types. The formal logic for abstract data types used in the formal method is first-order predicate logic, and the proof system uses natural deductive logic. This is the background formal logic system, and the semantic part of each object definition uses this logic. A solution to the copyability problem is presented using the new properties of inheritance relation in copyable and out copyable, as well as client-server fan in copyable and fan out copyable. This solution to the copyability problem is presented by means of an effective method using a framework for identifying and assessing potential errors in a given object- oriented structure. Several different kinds of formal logic errors are identified which can occur during copying of object definitions represented as abstract data types into object-oriented structures.     

在O/R Mapping时保留的Java Collection特性

根据国家“863”项目中对复杂对象的存储与建模的研究，一种Java collection O／R mappillg的实现方法被提出，该方法可以在mapping的过程中保留collection的特性，并且由于在mapping时整合了collection在Java中的继承层次关系，因此在查询时呵以有效分地进行类型转换。