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Research And Implementation On Mobile Agent For Network Computing

Posted on:2001-07-30Degree:DoctorType:Dissertation
Country:ChinaCandidate:G WuFull Text:PDF
GTID:1118360092498886Subject:Computer Science and Technology
Abstract/Summary:PDF Full Text Request
With the research and development of computer science, the age of network is coming. Network Computing has. become the mainstream technology and an important computing paradigm. As a branch of it, mobile computing also receives much attention now. There are two kinds of computing models concerning the mobile character-Mobile Computing and Mobile Computation. The former studies the computing on the mobile devices, such as notebook and PDA, based on wireless network, while the later focuses on the mobile programs within the network. Mobile Agent (MA) technology studied in this paper is a kind of Mobile Computation.As the evolution of applications and the expansion of network scale, the traditional pattern of the exploitation and maintenance of the system becomes more and more difficult to meet the needs of network computing. Thus, the research on distributed computing have been outspreaded from different aspects to obtain a network computing environment that is open, extensible, customizible and high-usable. In this background Mobile Agent appears, which quickly becomes the hotspot in many fields such as computer software engineering, computer parallel theory, distributed object technology and network computing environment etc.This paper fully studies the different aspects of Mobile Agent by answering the five questions as follows:· What is Mobile Agent and Mobile Agent System?In this part the essential characters of Mobile Agent are analyzed, and the key attributes and active models of it are understood through formal method, and its computing paradigm and lifecycle model is presented as well. Furthermore, we clarify the basic architecture of Mobile Agent System. This set provides a good base for further study.· Why do we want Mobile Agent?This question is about the value of MA, which is one of the hotspots in this field. After thoroughly studying, we think that MA is the valuable complementarity and conclusion of current network computing model, but not a firenew or succedaneous model. The benefit of it is to provide a general computing framework which makes the information-based distributed systems be easily and effectively modeled and implemented. It also brings some new traits like the flexibility of system configuration and the improvement of performance to thedistributed applications. At the same time, a performance model of distributed applications is presented to show the value of MA quantificationally.· How to formalize and describe Mobile Agent?Theoretic guidance is necessary for the reliability and usability of the distributed systems, as well as the relevant formal developing methods and tools do. With the parallel theory, an asynchronous and high-order π calculus (AH π) is given by varying and extending Polyadic π calculus. AH π can directly describe the communication, mobility, interaction and other characters of MA when used as a formal tool. Then we present a type system of AH π , which make it possible to formally deduce the limitation of resource access in MA systems. An outstanding part of the type system lies in the introduction of recursive type.· How to produce the running environment for Mobile Agent?Both of the base architecture of MA system and the implementation of Aglets, one of the most popular MA system developed with Java language, are given in this section. Then, after discussing the selection standard of MA programming languages, we analyze the benefits and drawbacks of Java language as an example. The standardizing process between the mainstream MA systems is also presented based on CORBA. Moreover, we study the problem of reliable communication caused by the autonomous migration of MA, and present a novel algorithm on location management and reliable communication for Mobile Agents. In virtue of the algorithm, the messages for remote mobile agents can be trustworthily accepted even if the migration of MA can not be known in advance. And the exactly-once semantics of message delivery is guaranteed as well.· How to u...
Keywords/Search Tags:Mobile Agent, Mobile Agent System, Formal Model, Type System, Reliable Communication, Integrated Framework
PDF Full Text Request
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