Kaiyu Wan

An architecture for developing context-aware systems

This paper proposes a component-based architecture and development methodology for context-aware systems. A context is formally defined from relational point of view. The architecture of a context-aware system is conceived as a composition of the two components context constructor and context adapter. To process dynamically changing contextual information, we introduce context calculus as the formal basis of context manipulation. The information and its sources are abstracted within this formal definition. As an illustration of the principles involved in developing a context-aware system, we discuss the Anti-lock Braking System problem.

Intensional programming for agent communication

This article investigates the intensional programming paradigm for agent communication by introducing context as a first class object in the intensional programming language Lucid. For the language thus extended, a calculus of contexts and a logic of contexts are provided. The paper gives definitions, syntax, and operators for context, and introduces an operational semantics for evaluating expressions in extended Lucid. It is shown that the extended Lucid language, called Agent Intensional Programming Language(AIPL), has the generality and the expressiveness for being an Agent Communication Language(ACL).

Real time reactive programming in lucid enriched with contexts

We present a synchronous approach to real-time reactive programming in Lucid enriched with contexts as first class objects. The declarative intensional approach allows real-time reactive programs to manipulate both events and state-based representations of complex systems. We show the formal specification of the Train-Gate-Controller problem, a standard case study in real-time systems community, and formally verify the safety property.

Security Contexts in Autonomic Systems

Autonomic computing systems (ACS) are expected to achieve the same level of self-regulation and pervasiveness as human autonomic systems. Because of the features of ACS, the traditional security model can not be applied to ACS any more. The goal of our research is to develop a context-based security model and architecture for ACS. Our focus is on self-protection feature of ACS. The self-protection feature is enforced through security contexts that we define. By taking security contexts into account, security policies can dynamic change in order to cope with new environment

An intensional programming approach to multi-agent coordination in a distributed network of agents

We explore the suitability of Intensional Programming Paradigm for providing a programming model for coordinated problem solving in a multi-agent system. We extend our previous work on Lucx, an Intensional Programming Language extended with context as first class object, to support coordination activities in a distributed network of agents. We study coordination constructs which can be applied to sequential programs and distributed transactions. We give formal syntax and semantics for coordination constructs. The semantics for transaction expressions is given on top of the existing operational semantics in Lucx. The extended Lucx can be used for Internet-based agent applications.

Trustable Ad Hoc Networks of Agent Societies

Ad-hoc agent networks are self-organizing societies of agents. Each society of agents is composed of autonomous agents forming an ad-hoc network having no infrastructure. A network community has an interface agent that serves as the certified access point for that network. Communication between two agents within a society requires the cooperation of other agents in the society who will act as intermediaries. This paper proposes an incentive-based mechanism to promote trusted collaboration among agents within a society. Based on this mechanism and through the certified interface agents an agent in one society can securely interact with one or more agents in another society.

Context-Aware Mobile Tour Guide

This paper discusses the requirements for a context-aware mobile tour guide (MTG) and proposes a design for constructing it. With increasing wireless and network connectivity available in the world today, a MTG device is a powerful hand-held device for adaptive information gathering, query processing, and collaborative work among ad hoc groups of people. By mapping the requirements onto layered functional units and including the user as part of the system design the system complexity is reduced while enhancing the system usability