Friday, April 12, 2013

Giant Dinosaurs Were Fastest Growing Animals Ever

That repertoire turns out to be more intriguing than Thompson could
have imagined. Although the configuration program specified tasks for
all 100 cells, it transpired that only 32 were essential to the
circuit's operation. Thompson could bypass the other cells without
affecting it. A further five cells appeared to serve no logical
purpose at all--there was no route of connections by which they could
influence the output. And yet if he disconnected them, the circuit
stopped working.

It appears that evolution made use of some physical property of these
cells--possibly a capacitive effect or electromagnetic inductance--to
influence a signal passing nearby. Somehow, it seized on this subtle
effect and incorporated it into the solution.

-------------

Another challenge is to make the circuit work over a wide temperature
range. On this score, the human digital scheme proves its
worth. Conventional microprocessors typically work between -20 0C and
80 0C. Human designers set the clock so that chip components have
enough time to settle into a digital value. As many computer hackers
know, they can turn up the clock speed if they keep the temperature of
the microprocessor low because the transistors settle into their on or
off states more quickly when cold.

Thompson's evolved circuit only works over a 10 0C range--the
temperature range in the laboratory during the experiment. This is
probably because the temperature changes the capacitance, resistance
or some other property of the circuit's components. Whatever the
cause, this is a serious drawback. If the circuit needs a temperature
controller to enable it to operate, then it is no longer a cheap,
low-power device. But evolution could come to the rescue here as well.
In a future genetic algorithm, Thompson plans to score circuits not
only on how well they perform an electronic task, but also on how well
they cope with temperature variation. Evolution might, for example,
create a design that includes a set of subcircuits each of which
operates over a different temperature range. If this fails to solve
the problem, Thompson will try giving the FPGA a clock. But he won't
tell the circuit what to do with it. "It will be a resource--we'll see
what use evolution makes of it," he says.

Source: http://rss.slashdot.org/~r/Slashdot/slashdotScience/~3/EpAdP9E97uE/story01.htm

aziz ansari aziz ansari katherine jenkins peyton manning broncos mexico city earthquake stand your ground law dancing with the stars season 14

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.