AI{based Trading in Open Distributed Environments

An open distributed environment can be perceived as a service market where services are freely o ered and requested. Any infrastructure which seeks to provide appropriate mechanisms for such an environment has to include mediator functionality (i.e. a trader) that matches service requests and service o ers. Commonly, the matching process is based upon some IDL{based service type de nition, and the types of the various services have to be \standardized" and distributed a priori to all potential participants. We argue that such well de ned \standards" are too in exible and even contradict the idea of an open service market. Therefore we propose a new type notation based on conceptual graphs. The trader maintains a knowledge base about service types in form of conceptual graphs. During the trader operations the service type knowledge evolves as it is continuously re ned and extended. Users of the trading service interact with the trader and formulate queries in a corresponding notation that allows for a conceptual speci cation of the desired service type. Adequate matching algorithms and protocols have been implemented.