A Semantically-Based Task Model and Selection Mechanism in Ubiquitous Computing Environments

User centricity required by ubiquitous computing is about making services and information be prepared and delivered in the perspective of users rather than system elements. Task-oriented computing supports user centricity by representing users' goals in tasks. It bridges the gap between tasks and available services. This paper proposes a semantically-based generic model for describing tasks in ubiquitous computing environments. This model is used by a task selection algorithm that considers the context information of a user and the surrounding environment. Additionally, this paper proposes a pattern-based task reconfiguration algorithm. The algorithms are illustrated by a demo application conducted in our test bed, and by other examples of tasks selected under diverse situations. Evaluation results show a reasonable time overhead for the task selection algorithm.