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SEARCH ENGINE EXTRACTS DESIRED CONTENT FROM VIDEO DATABASES

At the present time, it's difficult and time consuming to search through video databases for specific content because video graphics involve much more data than still pictures. However, a prototype search engine developed by engineers at Mitsubishi Electric Corp. in Japan is expected to make the task much easier.

The engineers used advanced MPEG7 video compression technology to develop a search engine that enables data to be handled like graphic elements. Users can search for specific scenes by inputting a rough sketch of what they are looking for. The system then uses the input to search for scenes with similar images in a MPEG7 database on magnetic disk.

The experimental search engine has been able to locate a desired scene almost instantly, although its success to date is due partly to the fact that the system currently contains only limited data. The engineers plan to add more data through which to search, plus a function that narrows down conditions for the search and enhances the system's accuracy.

For information: Mitsubishi Electric Corp., Mitsubishi Denki Bldg., 2-3 Marunouchi, 2-chome, Chiyoda-ku, Tokyo 100, Japan, telephone: 011-81-3-3218-2111.

RELIABLE, BROADBAND, INFRARED COMMUNICATION SYSTEM

A new link design is the key to a reliable, broadband, wireless, local area network (LAN) built by engineers at Penn State's Center for Information and Communications Technology Research.

Line-of-sight or point-to-point infrared signal transmissions, which are used in TV remote controls, are very efficient at low power levels but require alignment between the transmitter and the receiver. If blocked, the signals cannot get through.

Non-line-of-sight transmission systems use a broad diffuse beam and don't require alignment for transmissions, but they suffer from low power efficiency and low broadband and error rate values.

Penn State's new link design incorporates a multi-beam transmitter with a narrow field-of-view receiver. To form an indoor LAN for a group of computers, each computer is equipped with a low power infrared source and a holographic beam splitter. The low power beam is separated into several narrow beams, which strike the ceiling and walls and form an invisible grid throughout the room. These beams are reflected at each of the strike points and used to send or receive information. The narrow field-of-view receivers filter out noise and provide continued coverage, even if some of the transmitter beams are blocked.

The system has a bit-error rate of only one error per billion bits in 99 percent of the coverage area at bit rates up to a few hundred megabits per second and uses transmitted power levels below one watt.

For information: Mohsen Kavehrad, Penn State, 0229 Electrical Engineering East, University Park, PA 16802, telephone: (814) 865-7179.