Abstract: A document categorization system, including a clusterer for generating clusters of related electronic documents based on features extracted from the documents, and a filter module for generating a filter on the basis of the clusters to categorize further documents received by the system. The system may include an editor for manually browsing and modifying the clusters. The categorization of the documents is based on n-grams, which are used to determine significant features of the documents. The system includes a trend analyzer for determining trends of changing document categories over time, and for identifying novel clusters. The system may be implemented as a plug-in module for a spreadsheet application for permitting one-off or ongoing analysis of text entries in a worksheet.

Abstract: A device (10) for detecting the presence of an airborne, electrically conductive particle, the device including spaced conductors (24,26) and a circuit (12) for detecting when the electrically conductive particle forms a conducting path between the spaced conductors (24,26). The conductors (24,26) are provided in a grid (14) of alternate elongate conductors, and the circuit (12) applies a voltage to one set (24) of conductors sufficient to detect and destroy the particle when it creates a conductive path to the alternate set (26) of conductors.

Abstract: A symbol for establishing a telephone call, has the following characteristics: (a) the symbol appears on a computer display; (b) a user can select and activate the symbol, which causes computer software associated with they symbol to activate telecommunications equipment which establishes the telephone call; (c) the symbol is “portable”, in that a user can cause it to be moved from any one of the following locations: (i) an Internet web page, (ii) an email message, (iii) a window associated with a computer program, (iv) a file directory folder, (v) and electronic form, (vi) a computer data storage medium, (vii) the user's operating system “desktop”, (viii) a personal digital assistant, Wireless Application Protocol phone or other mobile computing device; to one of the following locations: (I) the user's operating “desktop”, (II) an email message, (III) a window associated with a computer program, (IV) a file directory folder, (V) an electronic form, (VI) a computer data sto