We give semantic characterizations of the expressive power of navigational XPath (a.k.a. Core XPath) in terms of first order logic. XPath can be used to specify sets of nodes and sets of paths in an XML document tree. We consider both uses. For sets of nodes, XPath is equally expressive as first order logic in two variables. For paths, XPath can be defined using four simple connectives, which t...

In this paper we show how to improve the architecture of Web Information Systems (WISs) using design patterns, in particular navigational patterns. We first present a framework to reason about the process of designing and implementing these applications. Then we introduce navigational patterns and show some prototypical patterns. We next show how these patterns have been used in some successful...

In this paper, we propose a work-in-progress virtual reality system to explore how different ways of navigating emotionally-responsive artwork can change one’s phenomenal experience of the artwork in an immersive virtual reality environment. Two sets of navigational scenarios are designed from artwork generated from our parameterized NPR (non-photorealistic rendering) system ePainterly. Prelimi...

In this paper we present the autonomous and path planning functionalities of a Planetary Rover system. In order to make the Rover system completely independent of human intervention, a high level of navigational autonomy is desirable. Sun sensing and topographical properties are the two factors that are considered here as the Rover navigational aid. Autonomous hazard avoidance can be achieved u...

During the last four years we have been developing hypermedia applications (in CDROM and in the Web) using the Object-Oriented Hypermedia Design Method (OOHDM). OOHDM explicitly separates navigation from user interface design; this means that design decisions related with the navigational topology of the application are (in a broader sense) independent respect to those regarding interface issue...