The Rise and Fall of the dot com Entrepreneurs

This paper looks at the dot com phenomenon drawing mainly on examples from the USA where the boom started and was most pronounced, but also from the UK which had a number of high profile dot coms. It starts by asking the question, ‘Who were the dot coms?’. it then goes on to consider the factors which led to the emergence of the dot coms such as the emergence of the commercial Internet, the lowering of entry barriers which followed from this and the funding available for new businesses through venture capital. The article also looks at the reasons why it was believed that the dot coms represented a threat to established businesses. The article then looks at the booming IPO market for dot coms and the opportunities this provided for exit by venture capital investors. The crash of 2000 is considered, lessons are drawn for entrepreneurs and investors and finally the article will look at future prospects for the dot com sector

Functions preserving nonnegativity of matrices

The main goal of this work is to determine which entire functions preserve nonnegativity of matrices of a fixed order $n$ -- i.e., to characterize entire functions $f$ with the property that $f(A)$ is entrywise nonnegative for every entrywise nonnegative matrix $A$ of size $n\times n$. Towards this goal, we present a complete characterization of functions preserving nonnegativity of (block) upper-triangular matrices and those preserving nonnegativity of circulant matrices. We also derive necessary conditions and sufficient conditions for entire functions that preserve nonnegativity of symmetric matrices. We also show that some of these latter conditions characterize the even or odd functions that preserve nonnegativity of symmetric matrices.Comment: 20 pages; expanded and corrected to reflect referees' remarks; to appear in SIAM J. Matrix Anal. App

Knowledge-based monitoring of the pointing control system on the Hubble space telescope

A knowledge-based system for the real time monitoring of telemetry data from the Pointing and Control System (PCS) of the Hubble Space Telescope (HST) that enables the retention of design expertise throughout the three decade project lifespan by means other than personnel and documentation is described. The system will monitor performance, vehicle status, success or failure of various maneuvers, and in some cases diagnose problems and recommend corrective actions using a knowledge base built using mission scenarios and the more than 4,500 telemetry monitors from the HST

The postcolonial moment in security studies

In this article, we critique the Eurocentric character of security studies as it has developed since World War II. The taken-for-granted historical geographies that underpin security studies systematically misrepresent the role of the global South in security relations and lead to a distorted view of Europe and the West in world politics. Understanding security relations, past and present, requires acknowledging the mutual constitution of European and non-European worlds and their joint role in making history. The politics of Eurocentric security studies, those of the powerful, prevent adequate understanding of the nature or legitimacy of the armed resistance of the weak. Through analysis of the explanatory and political problems Eurocentrism generates, this article lays the groundwork for the development of a non-Eurocentric security studies.</jats:p

A comparison of videolaryngoscopes for tracheal intubation in predicted difficult airway: a feasibility study

Videolaryngoscopy has become increasingly attractive for the routine management of the difficult airway. Glidescope® is well studied in the literature while imago V-Blade® is a recent videolaryngoscope. This is a feasibility study with 1:1 case-control sequential allocation comparing Imago V-Blade ® and Glidescope® in predicted difficult airway settings