Monday, September 27, 2010

NEW SUPERCOMPUTER SEES WELL ENOUGH TO DRIVE A CAR SOMEDAY

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Navigating our way down the street is something most of us take for granted; we seem to recognize cars, other people, trees and lampposts instantaneously and without much thought. In fact, visually interpreting our environment as quickly as we do is an astonishing feat requiring an enormous number of computations—which is just one reason that coming up with a computer-driven system that can mimic the human brain in visually recognizing objects has proven so difficult.

Now Eugenio Culurciello of Yale’s School of Engineering & Applied Science has developed a supercomputer based on the human visual system that operates much more quickly and efficiently than ever before. Dubbed NeuFlow, the system takes its inspiration from the mammalian visual system, mimicking its neural network to quickly interpret the world around it. Culurciello presented the results Sept. 15 at the High Performance Embedded Computing (HPEC) workshop in Boston, Mass.

The system uses complex vision algorithms developed by Yann LeCun at New York University to run large neural networks for synthetic vision applications. One idea—the one Culurciello and LeCun are focusing on, is a system that would allow cars to drive themselves. In order to be able to recognize the various objects encountered on the road—such as other cars, people, stoplights, sidewalks, not to mention the road itself—NeuFlow processes tens of megapixel images in real time.

The system is also extremely efficient, simultaneously running more than 100 billion operations per second using only a few watts (that’s less than the power a cell phone uses) to accomplish what it takes bench-top computers with multiple graphic processors more than 300 watts to achieve.

“One of our first prototypes of this system is already capable of outperforming graphic processors on vision tasks,” Culurciello said.

Culurciello embedded the supercomputer on a single chip, making the system much smaller, yet more powerful and efficient, than full-scale computers. “The complete system is going to be no bigger than a wallet, so it could easily be embedded in cars and other places,” Culurciello said.

Beyond the autonomous car navigation, the system could be used to improve robot navigation into dangerous or difficult-to-reach locations, to provide 360-degree synthetic vision for soldiers in combat situations, or in assisted living situations where it could be used to monitor motion and call for help should an elderly person fall, for example.

Yale University

RESEARCH SHOWS RADIOMETRIC DATING STILL RELIABLE (AGAIN)

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Recent puzzling observations of tiny variations in nuclear decay rates have led some to question the science of using decay rates to determine the relative ages of rocks and organic materials. Scientists from the National Institute of Standards and Technology (NIST), working with researchers from Purdue University, the University of Tennessee, Oak Ridge National Laboratory and Wabash College, tested the hypothesis that solar radiation might affect the rate at which radioactive elements decay and found no detectable effect.

Atoms of radioactive isotopes are unstable and decay over time by shooting off particles at a fixed rate, transmuting the material into a more stable substance. For instance, half the mass of carbon-14, an unstable isotope of carbon, will decay into nitrogen-14 over a period of 5,730 years. The unswerving regularity of this decay allows scientists to determine the age of extremely old organic materials—such as remains of Paleolithic campfires—with a fair degree of precision. The decay of uranium-238, which has a half-life of nearly 4.5 billion years, enabled geologists to determine the age of the Earth.

Many scientists, including Marie and Pierre Curie, Ernest Rutherford and George de Hevesy, have attempted to influence the rate of radioactive decay by radically changing the pressure, temperature, magnetic field, acceleration, or radiation environment of the source. No experiment to date has detected any change in rates of decay.

Recently, however, researchers at Purdue University observed a small (a fraction of a percent), transitory deviation in radioactive decay at the time of a huge solar flare. Data from laboratories in New York and Germany also have shown similarly tiny deviations over the course of a year. This has led some to suggest that Earth's distance from the sun, which varies during the year and affects the planet's exposure to solar neutrinos, might be related to these anomalies.

Researchers from NIST and Purdue tested this by comparing radioactive gold-198 in two shapes, spheres and thin foils, with the same mass and activity. Gold-198 releases neutrinos as it decays. The team reasoned that if neutrinos are affecting the decay rate, the atoms in the spheres should decay more slowly than the atoms in the foil because the neutrinos emitted by the atoms in the spheres would have a greater chance of interacting with their neighboring atoms. The maximum neutrino flux in the sample in their experiments was several times greater than the flux of neutrinos from the sun. The researchers followed the gamma-ray emission rate of each source for several weeks and found no difference between the decay rate of the spheres and the corresponding foils.

According to NIST scientist emeritus Richard Lindstrom, the variations observed in other experiments may have been due to environmental conditions interfering with the instruments themselves.

"There are always more unknowns in your measurements than you can think of," Lindstrom says.

(Photo: ©Zoltan Pataki/courtesy Shutterstock)

National Institute of Standards and Technology (NIST)

AEROBIC EXERCISE RELIEVES INSOMNIA

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The millions of middle-aged and older adults who suffer from insomnia have a new drug-free prescription for a more restful night’s sleep. Regular aerobic exercise improves the quality of sleep, mood and vitality, according to a small but significant new study from Northwestern Medicine.

The study is the first to examine the effect of aerobic exercise on middle-aged and older adults with a diagnosis of insomnia. About 50 percent of people in these age groups complain of chronic insomnia symptoms.

The aerobic exercise trial resulted in the most dramatic improvement in patients’ reported quality of sleep, including sleep duration, compared to any other non-pharmacological intervention.

“This is relevant to a huge portion of the population,” said Phyllis Zee, M.D., director of the Sleep Disorders Center at Northwestern Medicine and senior author of a paper to be published in the October issue of Sleep Medicine. The lead author is Kathryn Reid, research assistant professor at Feinberg.

“Insomnia increases with age,” Zee said. “Around middle age, sleep begins to change dramatically. It is essential that we identify behavioral ways to improve sleep. Now we have promising results showing aerobic exercise is a simple strategy to help people sleep better and feel more vigorous.”

The drug-free strategy also is desirable, because it eliminates the potential of a sleeping medication interacting with other drugs a person may be taking, Reid said.

Sleep is an essential part of a healthy lifestyle, like nutrition and exercise, noted Zee, a professor of neurology, neurobiology, and physiology at Northwestern University Feinberg School of Medicine and a physician at Northwestern Memorial Hospital.

“By improving a person’s sleep, you can improve their physical and mental health,” Zee said. “Sleep is a barometer of health, like someone’s temperature. It should be the fifth vital sign. If a person says he or she isn’t sleeping well, we know they are more likely to be in poor health with problems managing their hypertension or diabetes.”

The study included 23 sedentary adults, primarily women, 55 and older who had difficulty falling sleep and/or staying asleep and impaired daytime functioning. Women have the highest prevalence of insomnia. After a conditioning period, the aerobic physical activity group exercised for two 20-minute sessions four times per week or one 30-to-40-minute session four times per week, both for 16 weeks. Participants worked at 75 percent of their maximum heart rate on at least two activities including walking or using a stationary bicycle or treadmill.

Participants in the non-physical activity group participated in recreational or educational activities, such as a cooking class or a museum lecture, which met for about 45 minutes three to five times per week for 16 weeks.

Both groups received education about good sleep hygiene, which includes sleeping in a cool, dark and quiet room, going to bed the same time every night and not staying in bed too long, if you can’t fall asleep.

Exercise improved the participants’ self-reported sleep quality, elevating them from a diagnosis of poor sleeper to good sleeper. They also reported fewer depressive symptoms, more vitality and less daytime sleepiness.

“Better sleep gave them pep, that magical ingredient that makes you want to get up and get out into the world to do things,” Reid said.

The participants’ scores on the Pittsburgh Sleep Quality Index dropped an average of 4.8 points. (A higher score indicates worse sleep.) In a prior study using t’ai chi as a sleep intervention, for example, participants’ average scores dropped 1.8 points.
“Exercise is good for metabolism, weight management and cardiovascular health and now it’s good for sleep,” Zee said.

The research was funded by the National Institute on Aging.

Northwestern University

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