Abstract: An interactive system for the exchange of knowledge over a network, including, a server that is accessible by user client stations via a communication network, an interactive knowledge exchange application for running on the server, wherein the application is adapted to enable a user to log on to use the application as an instructor or a student. Wherein a user logged on as an instructor can provide an online course for teaching students, and a user logged on as a student can select to participate online in courses offered by instructors.

Abstract: A flat, ultra wideband, unidirectional antenna is disclosed, the antenna may comprise a pair of active elements having the shape of substantially half-circles or half-ellipsoids made of thin conductive material and a ground element made of thin conductive material placed parallel and against to the active electrodes and spaced from them, the antenna having a nominal gain of at least 6 dbi and variations of gain in that range of +/?1.5 dbi at its bore sight.