UML动态模型在关系数据库操作中的应用

UML作为一种面向对象的标准建模语言,在关系数据库系统的建模领域也得到了广泛的应用.用UML为关系数据库模式建立的模型比ER模型表达力更强,但目前的UML数据库建模技术主要强调静态模型.概述了如何使用UML动态建模方法为关系数据库操作建模.在建立的框架的基础上可为原子数据库操作建模,进而为更复杂的数据库操作建模.这种方法将为用户和开发者提供对整个系统的一个统一视角,将UML的强大功能扩展到数据库领域.     

触发器在管理信息系统中的应用

本文对触发器的概念和功能作了详细的介绍,并针对 ＯＲＡＣＬＥ数据库,举例说明如何在信息 管理系统中应用触发器。     

基于Web2．0的数字音乐图书馆

针对现有数字音乐图书馆系统在音乐展现方面的不足,设计一个基于Web2．0技术的数字音乐图书馆体系结构,能有效支持音乐内容数据和特征数据的交互式学习。实现一个基于上述体系结构的数字音乐图书馆原型系统Music Spirit,通过应用Ajax和web2．0技术基于内容地展现音乐数据。实验结果表明该系统能有效提高数字音乐素质教育的效率。     

GKD-Base中DML触发器的设计

GKD-Base中的DML触发器,其PL/SQL引擎由前端编译器和后端解释执行器组成.前者含语言预处理、SQL语句和过程语句分析,及中间代码生成等.后者则对前端编译器生成的中间代码进行解释执行,且系统运行时DML触发器扩展为六元组,即ECA模型.该触发器的设计包括数据字典、编译与储存、激发与执行等.     

External relationships of objects

External relationships of objects represent semantic dependencies between objects that enable inter-object communication and augment the services the objects provide with role-specific behaviors. Most of the object-oriented design methodologies support the notion of external relationships at the conceptual level, but OO programming languages have no language construct to directly implement the external relationships, which are implemented as containment relationships with embedded pointers resulting in the semantics of the relationships being buried in code. Moreover, object-oriented programming languages lack a mechanism to allow a dynamic classification of objects according to the roles they play in external relationships. This paper describes a technique to treat an external relationship as a conceptually useful abstraction at the specification stage and a separately identifiable structure at the implementation stage, by providing a declarative specification and an implementation in C++ with special focus on the implementation of object roles. © 1998 John Wiley & Sons, Ltd.     

Degradation kinetics of monacolin K in red yeast rice powder using multiresponse modeling approach

The effects of storage temperature (4, 20, 30, 40, 50 °C) and atmospheric conditions in packages (vacuum, atmospheric) on degradation kinetics of monacolin K, an antihypercholesterolemic agent, in red yeast rice powder were investigated using multiresponse modeling approach. Storage of red yeast rice powder at 4 °C under vacuum package was found to enhance retention of monacolin K. Multiresponse modeling revealed degradation path of monacolin K acid form into their dehydromonacolin K and unknown product under vacuum package, while oxidized product was also formed under atmospheric package. Monacolin K lactone form and precursor were degraded into dehydromonacolin K lactone form, while degradation of dehydromonacolin K lactone form to unknown was more pronounced at temperature higher than 30 °C. Oxidized product was also generated from monacolin K lactone form in atmospheric package. High activation energy of monacolin K degradation in acid form indicated that degradation of monacolin K to their dehydromonacolin K was more susceptible to temperature change as compared to lactone form.