Let Q be the set of all primitive words over a finite alphabet having at least two letters. In this paper, we study the language D(1) of all non-overlapping (d-primitive) words, which is a proper subset of Q. We show that D(1) is a contextsensitive langauage but not a deterministic context-free language. Further it is shown that [D(1)]n is not regular for n ≥ 1. key words: primitive word, non-o...

— There are no general context-aware architectures to be useful which could be applied to full life cycle in ubiquitous VR, even though many context-aware architectures or middleware are proposed. In this paper, we propose a general approach of a context-aware architecture for ubiquitous virtual reality. We would discuss how to improve the intelligence ability in a context-aware architecture.

In this paper, we review different context classification systems that have been used to define elements of context. Although existing classification systems cover various types of context, in the development of context aware applications, only a few types of context have been used. In this work, we aim to build a context classification model based on Activity Theory that provides a basis both ...