In this paper we consider the transformation from (minimal) non-deterministic finite automata (NFAs) to deterministic finite cover automata (DFCAs). We want to compare the two equivalent accepting devices with respect to their number of states; this becomes in fact a comparison between the expressio...

Petri net modeling enables us to verify the protocol of interest formally. However, aside from formal verification, a new protocol really needs to be tested in a relatively realistic environment in which it interworks (or at least co-exists) with earlier or different versions of the same or similar ...

Many web - based information - seeking tasks are set in a social context where other people’s knowledge and advi ce improves success in finding information. However, when tightly - knit contacts (friends, family, colleagues) are not available, information seeking becomes more difficult. Inspired b...

Information seeking on the Web has become a central part of many daily activities. Even though information seeking is extremely common, there are many times when these tasks are unsuccessful, because the information found is less than ideal or the task could have been completed more efficiently. In...

Inspired by theories of how professionals enter into a reflective conversation with their work materials, the research area of interaction history seeks to make use of the accumulated actions of many people in working with digital objects. Despite compelling system designs and empirical results in l...

Collaborative tagging is a simple and effective method for organizing and sharing web resources using human created metadata. It has arisen out of the need for an efficient method of personal organization, as the number of digital resources in everyday lives increases. While tagging has become a...

One of the main approaches for creating metadata for learn- ing resources in adaptive e-learning systems has been through the use of semantic web ontologies. This approach is limiting because it doesn’t usu- ally address a requirement for the support of annotators or the require- ment for signific...

This paper outlines our experiences with applying collaborative tagging in e-learning systems to supplement more traditional metadata gathering approaches. Over the last 10 years, the learning object paradigm has emerged in e-learning and has caused standards bodies to focus on creating metadata...

Steering and driving tasks – where the user controls a vehicle or other object along a path – are common in many simulations and games. Racing video games have provided users with different views of the visual environment – e.g., overhead, first-person, and third-person views. Although researc...