Abstract : The UMBCTAC agent was one of the top ranked agents in the third international Trading Agent Competition (TAC'02). This paper describes and evaluates the key heuristics used by UMBCTAC. including the early bird heuristic, the balance heuristic, and the separation heuristic. We developed a simple gain- risk model to search safe and profitable allocations for hotel rooms and airline tickets. We also used a novel probabilistic approach to dynamically allocate entertainment tickets and bid in entertainment auctions. We conclude with a description of ongoing and planned work.

The semantic web suggests having data and information on the web defined and linked in a way that it is both human readable and machine understandable. Machine understandability means that data has been explicitly prepared for programs and softrware agents to reason about and reuse. However, most current software agents have not been designed to run in a web environment: the software agents and web components are working in different models. For example, most software agent frameworks and tools do not support reasoning over content expressed in a mixture of several ontologies. Web components, on the other hand, lack notions of autonomy and a rich message-oriented communication. This thesis suggests adding to a semantic web site a dedicated service agent, capable of understanding the ontologies used by the site and answering queries about the content found on the site. Semantic web tasks are accomplished by the cooperation of personal agents, service agents and semantic web servers. The semantic web language OWL is used as the agent content language for message passing and interaction. An OWL inference engine, F-OWL, has been developed to manage logical sentences explicitly stated in the web documents as well as those that can be inferred. Within this thesis, TAGA system, a Trading Agent System running in the open Agentcities platform, is used to support the hypothesis and demonstrate how the software agent and semantic web paradigms can be integrated. We see two main contributions in our work. First, this thesis presents an enhanced semantic web vision involving software agents, semantic web and web services. Both human and software agents can directly access the semantic-marked web pages through web interface. An agent communicates with other agents by exchanging messages encoded in a semantically rich agent communication language. Both web services and agent services are described in a semantically rich language to improve the interoperability. The personal agents and service agents work together to understand the semantic web content, automate web services and better serve humans. Second, the TAGA system attests this semantic web vision and provides a flexible environment for simulating agent-based trading in dynamic markets.

Understanding and using the data and knowledge encoded in semantic web documents requires an inference engine. F-OWL is an inference engine for the semantic web language OWL language based on F-logic, an approach to defining frame-based systems in logic. F-OWL is implemented using XSB and Flora-2 and takes full advantage of their features. We describe how F-OWL computes ontology entailment and compare it with other description logic based approaches. We also describe TAGA, a trading agent environment that we have used as a test bed for F-OWL and to explore how multiagent systems can use semantic web concepts and technology.

Travel Agent Game in Agentcities (TAGA) is the framework that extends and enhances the Trading Agent Competition (TAC) scenario to work in Agentcities, an open multi agent environment based on FIPA compliant pla tforms. TAGA uses the semantic web languages and tools (RDF and OWL) to specify and publish the underlying common ontologies; as a content language within the FIPA ACL messages; as the basis for agent knowledge bases via XSB-based reasoning tools; to describe and reason about services. TAGA extends the FIPA protocols to support open market auctions and enriches the Agentcities with auction services. The introducing of the semantic web languages improves the interoperability among agents. TAGA is intended as a platform for research in multi-agent systems, the semantic web and automated trading in dynamic markets as well as a self-contained application for teaching and experimentation with these technologies.

As part of the Agentcities project, we have developed a prototype of an Evening Organiser application which allows users to flexibly and dynamically schedule activities within an itinerary. The Evening Organiser and the Web-accessible restaurant and cinema services which it uses have been developed within a generic service environment and the implementation of this has been built using the April Agent Platform, the DAML+OIL ontology language, the DAML Query Language and the Java Theorem Prover. This service environment is populated with agents of different natures, such as service instances and service finders. Service instances represent individual business entities, such as restaurants and cinemas. Service finders represent aggregated views over service instances, such as Yahoo!-hosted restaurants or Citysearch-hosted cinemas. The details of the implementation of these Web Services are described through the use of a motivating scenario. General Terms Algorithms, Design, Implementation, Experimentation, Languages.

Travel Agent Game in Agentcities (TAGA) is a framework that extends and enhances the Trading Agent Competition (TAC) scenario to work in Agentcities, an open multi agent environment based on FIPA compliant platforms. TAGA uses the semantic web languages and tools (RDF and OWL) to specify and publish the underlying common ontologies; as a content language within the FIPA ACL messages; as the basis for agent knowledge bases via XSB-based reasoning tools; to describe and reason about services. TAGA extends the FIPA protocols to support open market auctions and enriches the Agentcities with auction services. The introducing of the semantic web languages improves the interoperability among agents. TAGA is intended as a platform for research in multiagent systems, the semantic web and automated trading in dynamic markets as well as a self -contained application for teaching and experimentation with these technologies.

Darpa Agent Markup Language (DAML) [7] is the newest effort for Semantic Web [5]. It can be used to create ontologies and markup information resource like web pages. The information resource can be read by human and understood by agent programs. We believed DAML could be used to markup agent communication content and promote knowledge sharing and exchanging between agents. This paper also suggested an alternative model to connect web and agent together. We defined the necessary ontologies for agent communication in DAML language and described the agent communication scenario occurred in the ITTalks Project.

Effective use of the vast quantity of available information and services on the Internet will require multi-agent systems to be tightly integrated with existing web infrastructure. This however will be impossible unless the information on the web is presented in a semantic language, such as the DARPA Agent Markup Language (DAML), which is one aim of the “Semantic Web”. As part of our exploration of Semantic Web technology, and DAML in particular, we have constructed ITTALKS, a web-based system for automatic and intelligent notification of information technology talks. In this paper, we describe the ITTALKS system, and discuss the numerous ways in which the use of Semantic Web concepts and DAML extend its ability to provide an intelligent online service to both the human community and, more interestingly, the agents assisting them.

Travel Agent Game in Agentcities (TAGA) is a framework that extends and enhances the Trading Agent Competition (TAC) system to work in Agentcities, an open multiagent systems environment of FIPA compliant systems. TAGA makes several contributions: auction services are added to enrich the Agentcities environment, the use of the semantic web languages RDF and DAML+OIL improve the interoperability among agents, and the DAML-S ontology is employed to support service registration, discovery and invocation. The FIPA and Agentcities standards for agent communication, infrastructure and services provide an important foundation in building this distributed and open market framework. TAGA is intended as a platform for research in multi-agent systems, the semantic web and/or automated trading in dynamic markets as well as a selfcontained application for teaching and experimentation with these technologies. It is running as a continuous open game at http://taga.umbc.edu/ and source code is available for research and teaching purposes.

Travel Agent Game in Agentcities (TAGA) is a framework that extends and enhances the Trading Agent Competition (TAC) scenario to work in Agentcities, an open multi-agent environment based on FIPA compliant systems. TAGA uses the semantic web languages and tools (RDF and DAML+OIL) to specify and publish the underlying common ontologies; as a content language within the FIPA ACL messages; as the basis for agent knowledge bases via XSB-based reasoning tools; to describe and reason about DAML-S based services. TAGA extends the FIPA protocols to support open market auctions and enriches the Agentcities with auction services. The introducing of the semantic web languages improves the interoperability among agents. TAGA is intended as a platform for research in multi-agent systems, the semantic web and automated trading in dynamic markets as well as a self-contained application for teaching and experimentation with these technologies.

Semantic Web markup languages will improve the automated gathering and processing of information and help integrate multiagent systems with the existing information infrastructure. The authors, describe their ITtalks system and discuss how Semantic Web concepts and DAML+OIL extend its ability to provide an intelligent online service.

We describe a research project on resolving semantic differences for multi-agent systems (MAS) in electronic commerce. The approach can be characterized as follows: (1) agents in a MAS may have their own specific ontologies defined on top of a shared base ontology; (2) concepts in these ontologies are represented as frame-like structures based on DAML+OIL language; (3) the semantic differences between agents are resolved at runtime through inter-agent communication; and (4) the resolution is viewed as an abductive inference process, and thus necessarily involves approximate reasoning.

Effective use of the vast quantity of information now available on the web will require the use of “Semantic Web” markup languages such as the DARPA Agent Markup Language (DAML). Such languages will enable the automated gathering and processing of much information that is currently available but insufficiently utilized. Effectively, such languages will facilitate the integration of multi-agent systems with the existing information infrastructure. As part of our exploration of SemanticWeb technology, and DAML in particular, we have constructed ITTALKS, a web-based system for automatic and intelligent notification of information technology talks. In this paper, we describe the ITTALKS system, and discuss the numerous ways in which the use of Semantic Web concepts and DAML extend its ability to provide an intelligent online service to both the human community and the agents assisting them.

Agent Game in Agentcities (TAGA) is designed and implemented to demonstrate agent and semantic web technology working together. It is developed on the foundation of FIPA technology and the Agentcities infrastructure, which provides the stable communication environment where messages expressed in semantic web languages can be exchanged. The agents and services use FIPA-supported languages, protocols and service interfaces to create the travel market framework. This market is the combination of auctions and varying markets including service registries, service brokerage, wholesalers, peer-to-peer transactions and bilateral negotiation. TAGA provides a test-bed for experimenting with agents, semantic web and web services as well as a rich and interesting scenario to test and challenge agent technology.

During 2002, as part of Agentcities project, we have developed three prototypes related to an Evening Organizer application, which allows users to flexibly and dynamically schedule activities within an evening plan. The Evening Organizer, and the Restaurant and Cinema services which compose it, have been developed within a generic service environment built using the April Agent Platform, the DAML+OIL ontology language, the DAML Query Language and the Java Theorem Prover. This service environment is populated with agents of different nature, such as service instance agents and service finder agents. Service instance agents represent individual business entities, such as restaurants and cinemas. Service finder agents represent aggregated views over service instances, such as Yahoo!-hosted restaurants or Citysearch-hosted cinemas. The implementation and usage of these services is described in its important details.