Modeling collaborations among objects that change their roles dynamically and its modularization mechanism

For the representation of the collaborative operations among objects (computational entities), many of the techniques proposed at present treat the collaborative operations only as the concept in analysis and design stages; moreover, the roles carried by the respective objects have the problem of being fixed from the beginning to the end. Based on the environment-adaptive computation model "ε computation" proposed by the authors, in this paper we will study from the language side a description method for the case of collaborative operations in which the group of objects changes their roles dynamically along with the progress of computation. Furthermore, we will present a method for defining the collaborative operations among objects as general collaboration protocol components and reuse them again. ε computation is a model in which the field where the group of objects operates collaboratively is considered as an environment for the individual objects; the object can change its roles and collaboration forms with other objects dynamically by entering the environment or leaving the environment.