中文摘要：

旨在从形式化抽象的角度来认识移动计算的本质特点，分析了志愿计算平台的特征，提出并分析了志愿计算中的3种角色以及志愿计算中资源和构件的概念，介绍了一种关于志愿计算的形式化模型和方法．对系统中的基本元素和交互关系进行了形式化的描述，并通过集合理论和操作规约，又以志愿计算平台XtremWeb为例，描述了构件化的志愿计算形式模型和方法，为系统地研究志愿计算形式化理论打下了基础。

英文摘要：

This paper aims at revealing the essence of volunteer computing from the point of view of formal abstraction. At first, three elements of volunteer computing are analyzed and outlined. It included some concepts of component and computing resource in volunteer computing. One formal model and method concerning volunteers are introduced. Resource roles such as the basic elements of systems are identified in the abstract model, and modeling volunteer systems by basic elements. Relationships among elements and relationship changes are also characterized, based on set theory and operational reduction rules. And take XtremWeb as an example. These elements and relationships are specified in a formal manner. All of the results can help to build a firm foundation for research of formalisms for volunteer computing.