杏吧原创

Microsoft reveals secrets behind Kinect

A paper published on Microsoft鈥檚 website describes some of the secrets behind the company鈥檚 Kinect gaming sensor. Its body-tracking algorithm, for example, assigns each pixel in the images it captures to a particular part of a player鈥檚 body. It begins by evaluating the pixel鈥檚 rough location 鈥� near the head or the feet, for example 鈥� and then assigns it to a more precise location: a hand, say, or a leg. Using this information, the system then calculates the likely position of the joints within each limb to build a 3D skeleton.

Artificial leaf mimics real plants

Why come up with new ways to generate clean energy, when we can copy what plants have been doing for millions of years? Daniel Nocera and colleagues at the Massachusetts Institute of Technology claim to have done just that with an artificial leaf that is simpler and more effective than those developed in the past. The 鈥渓eaf鈥� is actually a cheap, playing-card-sized solar cell immersed in water. In a process analogous to the first stages of photosynthesis, it uses energy from sunlight and a cheap catalyst to split water into hydrogen and oxygen. This can be stored, ready to be fed into an attached fuel cell to generate electricity when needed. The leaf was presented at a meeting of the American Chemical Society in Anaheim last month.

Robots enter the fray at Fukushima

Japan鈥檚 Monirobo radiation-monitoring robot is being joined by robots from abroad in efforts to stabilise the Fukushima Daiichi nuclear plant. A powerful uncrewed water cannon which can spray 9000 litres of water per minute up to 150 metres has arrived from Australia. Meanwhile, iRobot of Bedford, Massachusetts, has supplied four machines that are usually used for bomb disposal: two 510 PackBots and two larger 710 Warriors. Members of Japan鈥檚 Ground Self-Defence Force are being trained to operate them, though it is not yet clear how they will cope with high levels of radioactivity.