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Smartphone app keeps children from getting lost

RubberBand uses a sensor network to keep track of groups of children on field trips, and warns teachers when someone wanders off
Children should be seen in the herd
Children should be seen in the herd
(Image: Seiya Kawamoto/Getty Images)

SCHOOL field trips might be fun for kids, but try being a teacher having to keep track of dozens of little charges, each with a penchant for wandering off. Now an app that alerts teachers when a child is straying from the flock could help prevent anyone getting lost.

RubberBand uses a sensor attached to each child鈥檚 backpack that broadcasts a radio signal to all the other children鈥檚 sensors once every second. The signals are collected by a smartphone running software that measures the signal strength between every pair of children in the group to determine their locations relative to each other.

If a child toddles off, or a splinter group forms, the system plays a sound to alert the teacher and displays photos of the kids involved.

鈥淭his kind of work is invaluable even if we are able to prevent just one child from going missing,鈥 says Hyukjae Jang at the Korea Advanced Institute of Science and Technology in Daejeon. He will present the system at the UbiComp conference in Pittsburgh, Pennsylvania, in September.

In two tests, teachers found RubberBand let them get on with looking after the group without having to do constant head counts. 鈥淚 didn鈥檛 feel as stressed out,鈥 said one kindergarten teacher who tried the system.