Still the life continues putting pressure on me. It says there’s need to change.
Sorry to remove my “sad fun” story. I just don’t like seeing it on the first page :(
I don’t detail on the matters.
I feel so tired… so tired. I’ll be back with a fresh mind. Be sure… just a few weeks.
German researchers have developed a random number generator that uses a computer memory element, a flip-flop, to create an extra layer of randomness. The flip-flop switches randomly between two states of either one or zero. Just before the switch, the flip-flop is in a “metastable state” where its behavior cannot be predicted. After the metastable state, the contents of the memory are completely random. A larger array produces a more random number. The University of Hagen’s Bernhard Fechner and BTC AG’s Andre Osterloh’s experiments with arrays of flip-flop units found that the extra layer produces a number that is 20 times more random than conventional methods. The researchers say their random number generator can protect systems from third-party snooping, making private and sensitive transactions on the Internet more secure.
© 2010 INFORMATION, INC. Read full article here.
University of California, Berkeley researchers have created energy-scavenging nanofibers that can be woven into clothing and textiles. The nano-sized generators have piezoelectric properties, which enables them to use mechanical stress, stretches, and twists to create electricity. “This technology could eventually lead to wearable smart clothes that can power handheld electronics through ordinary body movements,” says Berkeley professor Liwei Lin. The nanofibers are flexible and inexpensive because they are made from organic polyvinylidene fluoride. During testing, the researchers tugged and tweaked the nanofibers and generated electrical outputs ranging from five to 30 millivolts and from 0.5 to three nanoamps. The researchers demonstrated average energy conversion efficiencies of 12.5 percent, with some going as high as 21.8 percent.
© 2010 INFORMATION, INC. Read full article.
China has demonstrated the most growth in scientific research of any country in the past three decades and is on pace to overtake the United States as the world’s scientific leader by 2020, according to a recent Thomson Reuters study. The study found that China has experienced a 64-fold increase in peer-reviewed scientific papers since 1981. “China is out on its own, far ahead of the pack,” says the Royal Society of London’s James Wilsdon. Chinese researchers also have become more eager to work with international colleagues, with almost nine percent of Chinese-based papers having at least one U.S.-based co-author. Three main factors are driving China’s boom of scientific research, Wilsdon says. The government has made an enormous financial investment, new scientific breakthroughs are organized to flow from basic science to commercial applications, and Chinese researchers based in the United States and Europe are being recruited back to China.
Copyright 2010 INFORMATION, INC.
The U.S. National Institute of Standards and Technology (NIST) has completed round one of its open competition to create a new Secure Hash Algorithm (SHA). The cryptographic community narrowed the first round’s 64 submissions down to 14 semifinalists. Fifty-one of the 64 algorithms submitted in 2008 met the competition’s minimum criteria, and it took the judges a year to examine the entries for flaws and weaknesses. “We were pleased by the amount and quality of the cryptanalysis we received on the first round candidates, and more than a little amazed by the ingenuity of some of the attacks,” says NIST’s Bill Burr. Five finalists are expected to be named from the 14 remaining entries by the end of this year, and a new standard, which will be named SHA-3, should be ready in 2012. SHA-3 will replace the SHA-1 and SHA-2 algorithms currently being used by NIST. This is the third open cryptographic competition conducted by NIST, the first coming in the 1970s, and the second in the 1990s.
Happy new year!
I hope it would be a year full of achievements, health and peace for all of us.
Best wishes,
Be happy ever!
I wonder why nowhere on the net is found that mention the requirements of the complement operation on automata or precisely define this operation.
In fact complement operation is only defined on deterministic automata. Applying it to NFAs will result to strange things. For example, consider the following automata:
You might think that its complement is the following automaton:
But it isn’t. The automaton above accepts both h and the empty string.
Another important thing about DFAs before applying the complement operation is to add a halt or sink state.
Thus for the following automaton:
The complement is as follows:
You should note that the complement of an automaton that accepts h doesn’t mean an automaton that accepts everything other than h. If fact the complement of an automaton with language L and alphabet ∑ is an automaton that accepts ∑* – L. So complementing an automaton that accepts h with alphabet {h} is an automaton that accepts h* except the string containing a single h. Therefore the complement automaton accepts h* – h = {λ,hh,hhh,hhhh,…}.
I hope it was useful ;)
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