R. Scott Cost

Swoogle: a search and metadata engine for the semantic web

Swoogle is a crawler-based indexing and retrieval system for the Semantic Web. It extracts metadata for each discovered document, and computes relations between documents. Discovered documents are also indexed by an information retrieval system which can use either character N-Gram or URIrefs as keywords to find relevant documents and to compute the similarity among a set of documents. One of the interesting properties we compute is <i>ontology rank</i>, a measure of the importance of a Semantic Web document.

Information retrieval on the semantic web

We describe an approach to retrieval of documents that contain of both free text and semantically enriched markup. In particular, we present the design and implementation prototype of a framework in which both documents and queries can be marked up with statements in the DAML+OIL semantic web language. These statements provide both structured and semi-structured information about the documents and their content. We claim that indexing text and semantic markup together will significantly improve retrieval performance. Our approach allows inferencing to be done over this information at several points: when a document is indexed, when a query is processed and when query results are evaluated.

Using Colored Petri Nets for Conversation Modeling

Conversations are a useful means of structuring communicative interactions among agents. The value of a conversation-based approach is largely determined by the conversational model it uses. Finite State Machines, used heavily to date for this purpose, are not sufficient for complex agent interactions requiring a notion of concurrency. We propose the use of Colored Petri Nets as a model underlying a language for conversation specification. This carries the relative simplicity and graphical representation of the former approach, along with greater expressive power and support for concurrency. The construction of such a language, Protolingua, is currently being investigated within the framework of the Jackal agent development environment. In this paper, we explore the use of Colored Petri Nets in modeling agent communicative interaction.

Coordinating agents using agent communication languages conversations

Internet agents are expected to accomplish their tasks despite heterogeneity; agents of different designs and of varying skills and domain knowledge need to interact successfully through knowledge and information exchange and effective coordination. We identify two distinct and separate problems that Internet agents are faced in an open and dynamic environment: knowledge sharing and coordination.

Integrating Distributed Information Sources with CARROT II

We describe CARROT II (C2), an agent-based architecture for distributed information retrieval and document collection management. C2 can consist of an arbitrary number of agents, distributed across a variety of platforms and locations. C2 agents provide search services over local document collections or information sources. They advertise content-derived metadata that describes their local document store. This metadata is sent to other C2 agents which agree to act as brokers for that collection, and every agent in the system has the ability to serve as such a broker. A query can be sent to any C2 agent, which can decide to answer the query itself from its local collection, or to send the query on to other agents whose metadata indicate that they would be able to answer the query, or send the query on further. Search results from multiple agents are merged and returned to the user. C2 differs from similar systems in that metadata takes the form of an automatically generated, unstructured feature vector, and that any agent in the system can act as a broker, so there is no centralized control. We present experimental results of retrieval performance and effectiveness in a distributed environment.

Agents Making Sense of the Semantic Web

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.

TKQML: A Scripting Tool for Building Agents

Tcl/Tk is an attractive language for the design of intelligent agents because it allows the quick construction of prototypes and user interfaces; new scripts can easily be bound at runtime to respond to events; and execution state is encapsulated by the interpreter, which helps in agent migration. However, a system of intelligent agents must share a common language for communicating requests and knowledge. We have integrated KQML (Knowledge Query Manipulation Language), one such standard language, into Tcl/Tk. The resulting system, called TKQML, provides several benefits to those building intelligent agent systems. First, TKQML allows easy integration of existing tools which have Tcl/Tk interfaces with an agent system by using TO to move information between KQML and the application. Second, TKQML is an excellent language with which to build agents, allowing on-the-fly specification of message handlers and construction of graphical interfaces. This paper describes the implementation of TKQML, and discusses its use in our intelligent agent system for information retrieval.

Agent Communication in DAML World

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.

INTELLIGENT AGENTS FOR MOBILE AND EMBEDDED DEVICES

The pervasive computing environments of the near future will involve the interactions, coordination and cooperation of numerous, casually accessible, and often invisible computing devices. These devices, whether carried on our person or embedded in our homes, businesses and classrooms, will connect via wireless and wired links to one another and to the global networking infrastructure. The result will be a networking milieu with a new level of openness. The localized and dynamic nature of their interactions raises many new issues that draw on and challenge the disciplines of agents, distributed systems, and security. This paper describes recent work by the UMBC Ebiquity research group which addresses some of these issues.

Agent development with Jackal

Jackal is a Java-based tool for communicating with the KQML agent communication language. Some features that make it extremely valuable to agent development are its conversation management facilities, flexible, blackboard style interface and ease of integration. Jackal has been developed in support of an investigation of the use of agents in enterprisewide integration of planning and execution for manufacturing.