This paper presents a formal system based on the notion of objects and asynchronous communication. Built on Milner's work on ß-calculus, the communication primitive of the formal system is purely asynchronous, which makes it unique among various concurrency formalisms. Computationally this results in a consistent reduction of Milner's calculus, while retaining the same expressive power. Seen semantically asynchronous communication induces a surprisingly different framework where bisimulation is strictly more general than its synchronous counterpart. This paper shows basic construction of the formal system along with several illustrative examples. 1 Introduction The formal system introduced in this paper is intended to accomplish two purposes. First, it provides a simple and rigorous formalism which encapsulates essential features of concurrent object-orientation [26, 25]. Being successful as a programming methodology for dynamic concurrent computing, its theoretical contents are far f...

In this paper, we discuss the principle of synthetic pheromones, which we view as a high level coordination mechanism suitable for highly scalable, open and self-organized systems, of which peer to peer systems are an example. We present a stable abstraction for the application of synthetic pheromones, building on an existing coordination mechanism, objectspaces. The coordination principle is evaluated on the problem of search in a file-sharing P2P system.

A computing environment in the next decade will be widely distributed, open-ended, and ever-changing. We are developing a few computational models/paradigms in order to give possible foundations for computation in such an environment. The Computational Field Model is proposed to provide the fundamental framework based on the notion of concurrent objects. Cooperative computing and distributed constraint satisfaction are then proposed to serve as computational paradigms in the computational eld. The Muse operating system is being developed to provide users with a exible and self-advancing distributed computational environment through the proposed models/paradigms. The Muse operating system is equipped with a reective architecture and class system, and supports object migration and portable/mobile computers. 1 Introduction We foresee that computing environments in the next decade will be very widely distributed, ubiquitous, open-ended, and ever-changing. All the computers in the world wi...