由於網際網路的興盛，網路服務的發展越來越重要。除了簡單的網路
服務之外，複合服務的需求開始升高，然而目前的複合服務技術大多
是靜態的，無法因應網路環境的改變而改變，同時執行服務的行為都
一樣，不會因為使用者需求不同而有不同的複合服務行為。除了網路
服務之外，代理人服務也開始受到重視，然而目前的複合服務技術大
多針對某一種特定種類的服務，而不能同時使用多種不同種類服務來
合成複合服務。本論文將會提出一個基於PPN(Probabilistic Petri-Net)
整合SOA(Service Oriented Architecture)的MAS(Multi-Agent Systems)
系統的複合服務代理人架構，這個架構利用我們擴充的Contract Net
Protocol 來與會使用到的服務簽訂合約，等到複合服務代理人實際被
使用者呼叫時，就會利用PPN 找出適合服務組合來執行複合服務。
我們也擴充了BPEL4WS 為BPEL4WS/AS，使之能夠同時使用網路
服務與代理人服務來組成複合服務。

Due to the raise of the Internet, the development of web services has
become essential. Except for simple web services, the need of composite
services starts to increase. The composing methods used in existing
composite service technologies are mostly static, so it can not change
while the network environment changes. Current composite service
technologies always perform the same action to complete the composite
service regardless of the user needs. In addition to web services, agent
services have also attracted an increasing attention, but present composite
service technologies usually focus on a single kind of service and can not
compose different kinds of services. In this paper, we proposed a
framework for composite service agents under PPN(Probabilistic
Petri-Net)-based MAS(Multi-Agent Systems) which integrates
SOA(Service Oriented Architecture). We extend the Contract Net
Protocol to make contracts with services. When a user sends a request to
the composite service agent, it will query PPN-based middle agent to find
matched services for composing services. We also extends BPEL4WS
engine to BPEL4WS/AS engine that can be used to compose both web
services and agent services.

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