Gait recognition software could improve security surveillanceat a distance

Biometrics is commonly associated retinal scans, iris recognition and DNA databases, but researchers in India are working on another form of biometrics that could allow law enforcement agencies and airport security to recognize suspects based on the way they were, their characteristic gait. The team reveals details of a comprehensive framework for gait recognition by computer in the inaugural issue of the Inderscience publication, the International Journal of Biometrics.

C. Nandini of the Vidya Vikas Institute of Engineering & Technology and C.N. Ravi Kumar of the S.J. College of Engineering in Mysore, India, explain that human gait typifies the motion characteristics of an individual. Viewed from the side, we each have a unique gait that makes us easily recognizable. They point out that a camera with a side view can record a set of key frames, or stances, as a person heads for the security desk at an airport, military installation or bank, for instance. Key frames over the person's complete walk cycle, can then be converted into silhouette form and statistical analysis using so-called Shannon entropy, together with height measurements and the periodicity of the gait usedto classify the person's gait. The gait of individuals checking in at an airport could then be compared with the database, perhaps even before they enter the airport concourse. Such data compared with CCTV footage might also be used to track suspect terrorists or criminals who may otherwise be disguising their features or be carrying forged documents.

The researchers emphasize that gait recognition has a significant advantage over more well-known biometrics, such as fingerprinting and iris scanning in that it is entirely unobtrusive and can be used to identify an individual potentially from a considerable distance. "The ability to identify a possible threat from a distance gives personnel a longer time frame in which to react before a possible suspect becomes a real threat," the researchers say.

They carried out initial tests on 20 people recorded walk in a straight line at normal speed and stride, back and forth in front of a video camera placed perpendicular to their path. They obtained good recognition rates using the Shannon entropy equation and the individuals' height. Recognition performance of the system was sensitive to changes in big viewing angle above ten degrees but was reasonably robust even when the individuals changed walking speed.

Insufficient sleep among adolescents may not only contribute to lower grades and a lack of motivation, but may also increase the odds of serious levels of emotional and behavioral disturbances. The study, authored by Fred Danner, PhD, of the University of Kentucky, focused on 882 high school freshmen who provided informationabout their sleep habits and school grades and also completed psychological and behavioral assessments.

According to the results, students reported sleeping, on average, 7.6 hours per school night, with 48 percent reporting less than eight hours. Hours of sleep per school night were significantly positively associated with GPA and level of motivation, and significantly negatively associated with clinically significant levels of emotional disturbance and ADHD. Each additional hour of sleep on school nights lowered the odds of scoring in the clinically significant range of emotional disturbance and ADHD by 25 percent and 34 percent, respectively.

“Since these findings are based on associations rather than direct experimental manipulation, they cannot conclusively prove that insufficient sleep causes a loss of motivation, poor grades,ADHD, and emotional disturbance during adolescence,” said Dr. Danner. “The results, however, are consistent with a growing body of research that many adolescents do not get sufficient sleep and that even mild chronic sleep deprivation has serious effects on their psychological functioning. Lack of sleep should no longer be considered a traditional adolescent rite of passage because it can have serious consequences.”

It is recommended that adolescents get nine hours of nightly sleep. The American Academy of Sleep Medicine (AASM) offers the following tips on how to get a good night’s sleep:

• Follow a consistent bedtime routine.
• Establish a relaxing setting at bedtime.
• Get a full night’s sleep every night.
• Avoid foods or drinks that contain caffeine, as well as any medicine that has a stimulant, prior to bedtime.
• Do not stay up all hours of the night to “cram” for an exam, do homework, etc. If after-school activities are proving to be too time-consuming, consider cutting back on these activities.
• Keep computers and TVs out of the bedroom.
• Do not go to bed hungry, but don’t eat a big meal before bedtime either.
• Avoid any rigorous exercise within six hours of your bedtime.
• Make your bedroom quiet, dark and a little bit cool.
• Get up at the same time every morning.

Those who suspect that they might be suffering from a sleep disorder are encouraged to consult with their primary care physicianor a sleep specialist.