METU-EMar: An agentbased electronic marketplace on the web

Abstract. In this paper, we describe a scenario for a distributed marketplace on the Web where resource discovery agents find out about resources that may want to join the marketplace and electronic commerce is realized through buying agents representing the customers and the selling agents representing the resources like electronic catalogs. We propose a possible architecture which is based on the emerging technologies and standards. In this architecture, the resources expose their metadata using Resource Description Framework (RDF) to be accessed by the resource discovery agents and their content through Extensible Markup Language (XML) to be accessed by the selling agents by using Document Object Model (DOM). The marketplace contains Document Type Definitions (DTDs) and a dictionary of synonyms to be used by the buying agents to help the customer to specify the item s/he wishes to purchase. Distribution infrastructure is CORBA and Web on which the buying and selling agents find out about each other using Trading Object Services. The modifications necessary to the proposed architecture considering only the available technology are also discussed.

Design and implementation of a distributed workflow enactment service

Workflows are activities involving the coordinated execution of multiple tasks performed by different processing entities, mostly in distributed heterogeneous environments which are very common in enterprises of even moderate complexity. In current commercial workflow systems, the workflow scheduler is a single centralized component. A distributed workflow enactment service on the other hand should contain several schedulers on different nodes of a network each executing parts of process instances. Such an architecture would fit naturally to the distributed heterogeneous environments. Further advantages of distributed enactment service are failure resiliency and increased performance since a centralized scheduler is a potential bottleneck. In this paper we present the design and implementation of a distributed workflow enactment service based on the work given in [12]. Yet by starting with a block structured workflow specification language we avoid the very general set of dependencies and their related problems. In this way it is possible to present a simple algorithm for distributed scheduling of process instances. Further benefits of the approach are the ease in testing and debugging the system and execution efficiency through reduced number of messages.

ABSTRACT TASK HANDLING IN WORKFLOW MANAGEMENT SYSTEMS

Work ow management systems aim to automate the execution of business processes. One of the objectives of the work ow systems is to include the already existing applications such as legacy applications as well as new applications, which are termed as tasks, into the system and provide synchronized execution among them. To achieve this, amechanism is necessary to support the communication between the tasks and the system. The communication mechanism should handle the transfer of data necessary for the execution of the tasks and for the scheduling of the tasks. Another point tobenoted is the necessity of the handling user tasks that have to be performed by the users of the work ow system. Since the trend is toward distributed execution to avoid the bottlenecks due to the nature of central systems

A Workflow Specification Language and its Scheduler

This paper describes a workflow specification language, namely MFDL, and the implementation of its scheduler in a distributed environment. Distributed nature of the scheduling provides failure resilience and increased performance. Since workflow scheduling and management is highly affected from the way the workflow is specified, a workflow specification language should be efficient to prevent the problems of complexity in workflow specification and difficulties in debugging/testing the further steps of the workflow management system development. MFDL, being a block-structured procedural workflow specification language, is capable of defining a workflow in an easy, comprehensible and clear way so that implementation of the scheduler is simplified. The paper also presents task handling in the system through a CORBA compliant ORB. 1 Introduction Workflow management systems (WFMSs) automate the execution of business processes. WFMSs achieve considerable improvements in critical, ..