The moral objections to state-sponsored gambling were long ago swept away by courts and the apparently insatiable appetites of humans to wager on everything from horses and dogs to the whims of random-number generators
and bouncing pingpong balls.
Large-scale studies, which rely on high-speed random-number generators
and quicken the pace of volunteers' responses, seem to interfere with any psychokinetic effects, contends a group of psychokinesis researchers led by Dean Radin of the Institute of Noetic Sciences in Petaluma, Calif.
Using graph partitioning algorithms as an example, we demonstrate the often underestimated influence of these random-number generators on the result of the heuristic algorithms.
graph partitioning, heuristic algorithms, pseudo random-number generator
Monte Carlo applications are widely perceived as embarrassingly parallel.(1) The truth of this notion depends, to a large extent, on the quality of the parallel random-number generators
These random-number generators
are the algorithms of choice for applications such as encrypting credit card numbers in Internet transactions, for which unpredictability is of paramount importance.
However, defects in underlying uniform random-number generators
may result in poor quality of the nonuniform random variate.
Faulty randomness Researchers provided new mathematical insight into why certain random-number generators
give wrong results in some computational experiments and simulations (www.sciencenews.org/ 20030927/mathtrek.asp).
We tried the other LCGs mentioned above, as well as several other recommendable random-number generators
(such as those proposed by L'Ecuyer [1999a], for example), and their displays were similar to that of Figure 4, i.e., they behaved in agreement with [H.sub.0].
However, the most widely used multiplicative, congruential random-number generators
with modulus [2.sup.31] - 1 have a cycle length of about 2.1 x [10.sup.9].
Ferrenberg, a computational physicist at the University of Georgia in Athens, and his co-workers have discovered that even "high-quality" random-number generators
, which pass a battery of randomness tests, can yield incorrect results under certain circumstances.
"We've got a new situation in which conventional random-number generators
just won't do," says George Marsaglia, a computer scientist and statistician at Florida State University in Tallahassee.