Harry Chen

An ontology for context-aware pervasive computing environments

This document describes COBRA-ONT, an ontology for supporting pervasive context-aware systems. COBRA-ONT, expressed in the Web Ontology Language OWL, is a collection of ontologies for describing places, agents and events and their associated properties in an intelligent meeting-room domain. This ontology is developed as a part of the Context Broker Architecture (CoBrA), a broker-centric agent architecture that provides knowledge sharing, context reasoning and privacy protection supports for pervasive context-aware systems. We also describe an inference engine for reasoning with information expressed using the COBRA-ONT ontology and the ongoing research in using the DAML-Time ontology for context reasoning.

SOUPA: standard ontology for ubiquitous and pervasive applications

We describe a shared ontology called SOUPA - standard ontology for ubiquitous and pervasive applications. SOUPA is designed to model and support pervasive computing applications. This ontology is expressed using the Web ontology language OWL and includes modular component vocabularies to represent intelligent agents with associated beliefs, desires, and intentions, time, space, events, user profiles, actions, and policies for security and privacy. We discuss how SOUPA can be extended and used to support the applications of CoBrA, a broker-centric agent architecture for building smart meeting rooms, and MoGATU, a peer-to-peer data management for pervasive environments.

Semantic Web in the context broker architecture

This document describes a new architecture that exploits semantic Web technologies for supporting pervasive context-aware systems. This architecture called context broker architecture (CobrA) differs from other architectures in using the Web ontology language OWL for modelling ontologies of context and for supporting context reasoning. Central to our architecture is a broker agent that maintains a shared model of context for all computing entities in the space and enforces the privacy policies defined by the users when sharing their contextual information. We describe the use of CoBrA, its associated ontologies, and its privacy protection mechanism in an intelligent meeting room prototype.

Intelligent agents meet the semantic Web in smart spaces

A new smart meeting room system called EasyMeeting explores the use of multi-agent systems, Semantic Web ontologies, reasoning, and declarative policies for security and privacy. Building on an earlier pervasive computing system, EasyMeeting provides relevant services and information to meeting participants based on their situational needs. The system also exploits the context-aware support provided by the Context Broker Architecture (Cobra). Cobras intelligent broker agent maintains a shared context model for all computing entities in the space and enforces user-defined privacy policies.

The SOUPA Ontology for Pervasive Computing

This paper describes SOUPA (Standard Ontology for Ubiquitous and Pervasive Applications) and the use of this ontology in building the Context Broker Architecture (CoBrA). CoBrA is a new agent architecture for supporting pervasive context-aware systems in a smart space environment. The SOUPA ontology is expressed using the Web Ontology Language OWL and includes modular component vocabularies to represent intelligent agents with associated beliefs, desire, and intentions, time, space, events, user profiles, actions, and policies for security and privacy. Central to CoBrA is an intelligent broker agent that exploits ontologies to support knowledge sharing, context reasoning, and user privacy protection. We also describe two prototype systems that we have developed to demonstrate the feasibility and the use of CoBrA.

Dynamic Service Discovery for Mobile Computing: Intelligent Agents Meet Jini in the Aether

The emergence of ad-hoc pervasive connectivity for devices based on Bluetooth-like systems provides a new way to create applications for mobile systems. We seek to realize ubiquitous computing systems based on the cooperation of autonomous, dynamic and adaptive components (hardware as well as software) which are located in vicinity of one another. In this paper we present this vision. We also describe a prototype system we have developed that implements parts of this vision – in particular a system that combines agent oriented and service oriented approaches and provides dynamic service discovery. We point out why existing systems such as Jini are not suited for this task, and how our system improves on them.

Intelligent Agents Meet Semantic Web in a Smart Meeting Room

We describe a new smart meeting room system called EasyMeeting that explores the use of FIPA agent technologies, Semantic Web ontologies, logic reasoning, and security and privacy policies. Building on a pervasive computing system that we have developed previously, EasyMeeting can provide relevant services and information to meeting participants based on their situational needs. Our system exploits the context-aware support provided by the Context Broker Architecture (CoBrA). Central to CoBrA is an intelligent broker agent that maintains a shared model of context for all computing entities in the space and enforces the privacy policies defined by the users. We also describe the use of CoBrA ontologies, logic reasoning, and privacy protection mechanisms, and evaluate our initial user experience studies.

F-OWL: an inference engine for semantic web

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.

Creating Context-Aware Software Agents

Sharing ontologies, sensing context and reasoning are crucial to the realization of context-aware software agents. This document de- scribes our efforts in using the Resource Description Framework (RDF) and Prolog Forward Chaining (Pfc) system to provide support for ontology sharing and reasoning in the CoolAgent Recommendation System (CoolAgent RS), a context-aware multi-agent system. We also describes the implementation of the CoolAgent RS document and cuisine recommendation services that provide tailored services by exploiting users context.

Using semantic web technology in multi-agent systems: a case study in the TAGA trading agent environment

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.