Page 151 - Concise Encyclopedia of Robotics

Handshaking
certain drugs. Hallucinations can be, and often are, combined with delu-
sions, or misinterpretations of reality. An example is the person who
thinks that spies are after him or her, and who sees sinister figures lurking
behind trees or in dark alleyways.
Sophisticated computers can appear to have hallucinations and delu-
sions. The likelihood of such malfunctions, taking place in bizarre and
often inexplicable ways, increases as systems become more complex. This
is because, as computers become smarter, the number of components,
pathways, and nodes increases in exponential proportion, and the prob-
ability of a component failure or stray signal thus “blows up.” Computer
components are, in general, exceptionally reliable; however, given great
enough numbers of them, strange things can happen, and have happened.
Experienced personal computer users and technicians know this.
Some researchers in artificial intelligence (AI) believe that electronic
hallucinations or delusions might someday result from improper design
and care of machines. These researchers suspect that machines, as they
evolve and become more intelligent, can develop “hangups,”just as people
do.At present, malicious human operators cause more problems directly,
by means of such schemes as hacking and the writing of computer viruses,
than “computers gone mad.” In a few decades, however, autonomous
robots might become able to program and maintain themselves to a large
extent, and the situation might change. See AUTONOMOUS ROBOT.
HAND
See ROBOT GRIPPER.
HANDSHAKING
In a digital communications system, accuracy can be optimized by having
the receiver verify that it has received the data correctly. This is done
periodically—say, every three characters—by means of a process called
handshaking.
The process goes as follows, as illustrated in the figure. First, the trans-
mitter sends three characters of data. Then it pauses, and awaits a signal
from the receiver that says either of the following:
•(a) All three characters have familiar formats.
•(b) One or more characters has an unfamiliar format.
If the return signal is (a), the transmitter sends the next three charac-
ters. If the return signal is (b), the transmitter repeats the three characters.
In computer systems, the term handshaking refers to a method of con-
trolling,or synchronizing,the flow of serial data between or among devices.
The synchronization is accomplished by means of a control wire in

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