Researchers at The Johns Hopkins University have developed a new algorithm for filtering extraneous information in digital images. The MM-MNF algorithm is based on the Maximum Noise Fraction (MNF) transform, along with a nonlinear detection technique based on mathematical morphology. Immediate applications for the MM-MNF algorithm, which was developed by John Goutsias (a professor of electrical and computer engineering in Hopkins' Whiting School of Engineering) and doctoral students Ashish Banerji and Ulisses Braga-Neto, will be in systems designed to locate land mines with a high degree of accuracy. (A 1996 UNICEF report estimated that 110 million land mines have been distributed and abandoned throughout 64 countries.) Using minefield video images supplied by the Naval Surface Warfare Center, Goutsias et al. reported a 95 percent success rate in finding devices that had been placed above ground -- results significantly better than the previously used constant false alarm rate (CFAR) algorithm. A paper describing the algorithm is available at http:// iacl.ece.jhu.edu/~goutsias.
-- Jonathan Erickson
According to market-research firm International Data Corporation (IDC), commercial shipments of Linux will grow faster than total shipments of all other IDC-covered operating systems through the year 2003. IDC estimates that Linux commercial shipments will increase at a rate of 25 percent from 1999 through 2003, compared to 10 percent for other client operating environments combined and 12 percent for other server operating environments combined.
-- Jonathan Erickson
A new type of haptic (touch) interface based on magnetic levitation has been developed by researchers at Carnegie Mellon University. The device lets computer users physically interact with simulated objects and environments on their computer screens. What's unique about the device, which lets you not only touch objects, but reach in and manipulate them in three dimensions, is that it eliminates cables and other mechanisms common in haptic interfaces. Instead, the CMU device, developed by research scientist Ralph Hollis and doctoral student Peter Berkelman, has a single, lightweight moving part which floats on magnetic fields. More specifically, the system has a bowl-shaped floating element containing six levitation coils surrounded by strong, permanent magnets. A protruding handle attached to the bowl is grasped by users, enabling interaction with solid, 3D models graphically depicted on the computer screen. For more information, see http://www.cs.cmu.edu/~msl/haptic/ haptic_desc.html.
-- Jonathan Erickson
Many of the great physicists of the 1920s, 1930s, and 1940s got their start tinkering with radios. Fixing old radios meant playing with tubes and wires and watching the occasional failures go up in smoke. Like early radios, vintage computers were also physical marvels that got hot, made loud noises, and even shook while performing complex computations. These machines were expressive, conveying information in ways that used all five of our senses.
Interestingly, some of these odd quirks were put to good use. IBM 1620 or Altair programmers may recall placing AM radios next to computers and debugging programs based on the sounds generated by the computers' badly shielded radio frequencies. And then there was the UNIX developer who sat on a disk drive and optimized his file system code based on the vibrations of the drive. Talk about debugging by the seat of your pants.
Because we can no longer rely on the physical nature of computers to provide this type of feedback, Mark Weiser and a group of Xerox PARC researchers have started recreating it in various worthwhile ways. One PARC innovation, for instance, is a fountain that adjusts water flow based on Xerox's current stock price. When the fountain is gushing, so are Xerox's happy stock-holders.
Another PARC creation is the dangling string, invented by artist Natalie Jeremijenko. An eight-foot piece of string is attached to a small motor on the ceiling, which in turn is connected to a company's LAN. When a packet passes through the device, the string twitches. Observers can determine how busy the network is based on how wildly the string is moving. Both of these devices convey information that is not normally available in a relatively unobtrusive manner, key attributes of what Weiser calls "ubiquitous computing."
It's impossible to predict what the next great user-interface innovation will be, but remembering all of our senses and giving a nod to the past may suggest where the future lies.
-- Eugene Eric Kim
Motorola and the Massachusetts Institute of Technology have joined forces to establish the Motorola DigitalDNA Laboratory at MIT's Media Lab. The new lab will focus on the development of smart consumer products (set-top boxes, PDAs, wireless networks) that communicate with each other. This might include, for instance, clothing with computerized labels that tell a washing machine which cycle to use, and dishwashers that communicate with other household appliances about noise levels and energy usage. Motorola will fund the lab with a $5 million grant.
-- Jonathan Erickson
Quantum computing may have taken a step forward with the invention of a device by a team of physicists from Stanford and the University of California at Santa Barbara. The device, called a "quantum electron pump," moves electrons without relying on voltage differences to push them around. With quantum computers, digital computer's 0 and 1 bits are replaced by "qubits," which can be 0, 1, or both 0 and 1 at the same time. The quantum electron pump, designed by Stanford assistant professor Charles M. Marcus, Stanford graduate student Michael Switkes, UCSB professor Arthur C. Gossard, and UCSB graduate student Kenneth Campman, is fabricated in the semiconductor gallium arsenide. Electrons, acting as quantum-mechanical waves, enter the central cavity through the gaps on the left side of the structure. From the point of view of the electrons, the size of the cavity is determined by the strength of the electrical fields around it. The two electrode "plungers" in the right side distort the cavity's shape. When the electrodes operate in phase, the pump does not produce a flow of electrons. When the electrodes operate out of phase, the electrons begin to flow. For more information, see http:// www.stanford.edu/group/MarcusLab/ papers/Pumping.pdf.
-- Jonathan Erickson