多媒体对象的Agent展示集成模型*

根据多媒体对象的面向对象特点,给出了一种基于“事件-条件-动作”的Agent展示集成模型.该模型集对象的内容、时序、空间关系于一体,通过消息传递与对象展示状态事件控制对象展示集成的行为,保证了对象的封装性,并对用户的交互提供有力的支持,是一种动态集成模型.“事件-条件-动作”机制是主动数据库中广泛采用的方法,已有成熟的技术支持.通过对Allen所定义的时序关系的表示,说明了模型的表达能力,并通过实例加以验证.指出了展示集成模型在多媒体数据库中的作用.

An Agent Model for Integration of Multimedia Object Presentation

In this paper, an agent model for the integration of multimedia object presentation is established by using events-conditions-actions mechanism and considering object-oriented characteristics of multimedia objects. This model is a dynamic model, which integrates contents, temporal relations and spatial relations of multimedia objects and supports user interactions. Because it controls objects by message passing, the encapsulations of objects can be maintained. Events-conditions-actions mechanism is employed in active database intensively and has mature technologies. The expressive ability of this model is described by using it to the temporal relations defined by Allen, and it is also verified with an example. Its contributions to multimedia database systems are also analyzed.