We study weakly continuously Urysohn spaces, which were introduced in [Z]. We show that every weakly continuously Urysohn w∆-space has a base of countable order, that separable weakly continuously Urysohn spaces are submetrizable, hence continuously Urysohn, that monontonically normal weakly continuously Urysohn spaces are hereditarily paracompact, and that no linear extension of any uncountabl...

Following results of Bourgain and Gorelik we show that the spaces lp, 1 < p < ∞, as well as some related spaces have the following uniqueness property: If X is a Banach space uniformly homeomorphic to one of these spaces then it is linearly isomorphic to the same space. We also prove that if a C(K) space is uniformly homeomorphic to c0, then it is isomorphic to c0. We show also that there are B...

This paper establishes the equality of the observation spaces defined by means of piecewise constant controls with those defined in terms of differentiable controls. This research was supported in part by US Air Force Grant AFOSR-88-0235. keywords: Observation space, shuffle product, input-output system, generating series.

This chapter focuses on the World Wide Web (Web) as a provider of shared information landscapes. It reviews our work to design 3D spaces for information navigation and social interaction, and suggests an approach to such design based on an experiential theory of meaning. The increasing use of virtual 3D space in information environments is noted, and Personal Spaces are contrasted with Public P...

TV White Spaces have recently been proposed as an alternative to alleviate the spectrum crunch, characterised by the need to reallocate frequency bands to accommodate the ever-growing demand for wireless communications. In this paper, we discuss the motivations and challenges for collecting spectrum measurements in developing regions and discuss a scalable system for communities to gather and p...

University campuses are busy places for wireless client traffic coming from Wi-Fi connections and other wireless devices that contend for the 2.4 GHz frequencies space that most campus Wi-Fi networks use currently. This is making the 2.4 GHz frequency unsuitable for WiFi connection due to too much interference from other devices as well as from Wi-Fi connections themselves. TV white space could...