Tuning in "cognitive radios".
At 15, Haitao Zheng stood out at Chinas competitive Xian Jiaotong University for both her youth and her brilliance. Today, her work on so-called cognitive radios stands out for its potential to make a promising technology practical. Using software, cognitive radios dynamically detect and exploit unused radio frequencies; the devices could alleviate competition for the ever shrinking amount of unassigned radio spectrum. To be truly useful, though, a cognitive radio must not only detect free spectrum but also select the best frequency for a given function, all without interfering with other devices. At Microsoft Research Asia, Zheng created algorithms that allow disparate devices to “negotiate,” automatically allocating the available spectrum efficiently and fairly. Zheng is continuing her research on open spectrum systems as an assistant professor of computer science at the University of California, Santa Barbara.
Getting the most out of oil rigs.
Katrine Hilmen is helping to keep dwindling North Sea oil fields productive. The chemical engineer at ABBs research center in Norway developed innovative online monitoring and management tools for oil production platforms. Her technology monitors parameters such as heat, vibration, pressure, and flow rates, and can quickly identify a problem and its cause. The typical benefits: a 3 to 8 percent increase in oil production, a 10 to 15 percent reduction in operating expenses, and less pollution. Her innovations in process optimization, which have led to four patent filings, are widely studied by others in the field, enhancing their impact.
Inventing across disciplines.
A technological omnivore, Yael Maguire moves fearlessly among fields such as physics, engineering, biology, and software design. As a graduate student at MIT, he designed a sensor that makes the measurement of nuclear magnetic resonance between 10 and 100 times more sensitive but works on samples 1,000 to 10,000 times smaller than those required by current probes. Shuguang Zhang, associate director of MITs Center for Biomedical Engineering and Maguires thesis advisor, says the sensors will allow researchers to more easily obtain information valuable for designing new drugs. While a doctoral student at the MIT Media Laboratory, Maguire cofounded ThingMagic, where he is now co-chief technology officer, and pioneered the use of software-defined radio for the radio frequency ID chips that help track retail inventory more quickly and accurately. Maguires software allows a single reader to scan and decode hundreds of tags at once, no matter which of the many existing data protocols they use. Maguire also cofounded ThinkCycle, a nonprofit that encourages technologists to collaborate on problems in developing countries.
Taking the clocks out of computer chips.
The different functions of a computer chip are synchronized by an onboard clock, but that means the fastest operations cant pass on their data until the slowest have finished. Rajit Manohar, an associate professor of electrical and computer engineering, speeds up chips and lowers power consumption by removing the clock; his chips are 10 times more energy efficient than previous clockless chips. Instead of a separate clock network carrying a global timing signal, Manohars chips use short wires to carry signals that alert successive operations when the previous operations have finished. Last year, Manohar also built the first low-power processor for sensor networks: “You only activate the part of the chip thats doing the work you need,” he says. Such sensors could run on the same batteries for years instead of weeks.
Pulsing the way to efficient aircraft engines.
Adam Rasheed has made fundamental improvements to an aircraft propulsion system based on a pulsed-detonation engine – a technology in which a fuel-air mixture is compressed and exploded as many as 100 times per second. Pulsed detonation creates vastly higher pressures than the slower burn of a conventional engines combustion chamber, offering a theoretical 5 percent efficiency gain. Rasheed built a prototype that operates longer and without the oxygen enrichment required by other research efforts. And he was the first to use such technology in an important role: to drive the turbines that are at the heart of todays jet engines.
Unlocking digital doors.
Adam Stubblefield has become a champion at finding holes in supposedly secure systems. He proved that an early version of the wireless security protocol WEP was not secure, and helped crack the Secure Digital Music Initiatives electronic watermark. Stubblefield also helped reveal security flaws in Diebolds voting machine software – the first serious security review of the electronic-voting-machines code, according to Cindy Cohn, legal director of the Electronic Frontier Foundation. Most recently, Stubblefield reverse-engineered a radio frequency ID cipher. Yet he modestly notes hes not much of a programmer and has yet to learn to speak a foreign language. “My brain isnt very good at many things,” says Stubblefield, who received his doctorate from Johns Hopkins in the spring. But his brain is helping keep information systems from being used to encroach on civil liberties – a good thing indeed.