Researchers at the Georgia Institute of Technology have developed a system that encodes information onto chaos, transmits it, and then decodes the information away from the chaos. Rajarshi Roy, one of the researchers and chair of Georgia Tech's School of Physics, explains how it works. "In an ordinary digital signal, the message can immediately be seen," Roy reports. "But in our system, digital information is encoded in the chaos, so the message would not be obvious to a person who may intercept it." In the experimental system, a stable semiconductor diode laser produces a square wave "message" signal. That signal, amplified by an erbium-doped fiber amplifier (EDFA), is introduced into a chaotic signal produced by an erbium-doped fiber ring laser like that used in today's communications industry. The resulting combined signal, containing a mix of the message and chaotic carrier, moves through an optical fiber to a second EDFA nearly identical to the first. Upon encountering the combined signal, the receiving EDFA begins generating chaotic fluctuations synchronized with those produced by the transmitting laser. The chaotic portion of the signal, measured by a digital oscilloscope, is subtracted from the combined signal and low-pass filter to recover the original "coded" message. E-mail email@example.com.
Some of our culture's most enduring robots appeared in the 80s. The Aliens series produced another evil android, and we saw light robot fare in the form of Short Circuit. Two of the great robots of all time also showed up: The Terminator and RoboCop.
Major global metropolitan areas are implementing a vast number of technology, energy, transportation, and Internet projects to make the metropolis a friendlier, greener, safer, and more sustainable place to be.
Here’s a look at robots depicted in movies and on TV during the 1950s and 1960s. We tried to collect the classics here, omitting the scores of forgettable B movies such as Santa Claus Conquers the Martians and Dr. Goldfoot and the Bikini Machine. Stay tuned for slideshows of robot stars from later decades.
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