A dog called Hachi-kou...
Since I expect loyalty only from man, though...Power of Randomness
One of basic digital circuits in electronics is called a multiplexer.
When you want to select one from four different input lines, you need two selector lines, namely A and B in the above case.
As an electronic device today works following binary calculation inside, four pairs of values of A and B are possible: (0, 0), (0, 1), (1, 0) and (1, 1).
These two-digit expressions correspond to decimal values 0, 1, 2, and 3, respectively.
Nowadays this sort of function is embedded in a tiny IC chip as one of one million functions.
However, sometimes you have to control rocket engines of an unmanned space craft travelling 6 billion kilometers over seven years like Hayabusa of Japan, using this method.
http://en.wikipedia.org/wiki/Hayabusa
If you equip a space probe with four ion engines, you might have to choose only one for activation at one time. Or, when one engine depletes its fuel, another must be selected and fired.
But, if one of the selecting lines A or B got in trouble and you could use only one line B or A, you can use only two input engines, that is, "0" and "1," or "2" and "3" to select one of four (if a troubled line does not enter a high-impedeance state).
Then, how can you make this space probe fly, say, 6 billion kilometers over seven years like Hayabusa of Japan?
Anyway, this way of choosing input lines through use of gate signals, such as A and B, is applied in digital circuits embedded in electronic equipment of today.
In addition, to choose one from eight input lines, you need three selecting lines A, B, and C, since (100) = "4" and (101) = "5."
Now, I will install a random switching gate before the multiplexer, in case of malfunction of the gate lines of A and B.
By sending a signal X from the earth to the space craft, this switcher can be activated so that, for example, Input 0 would be changed to Input 3, Input 1 to 2, and so on, randomly or easily.
Accordingly, our space probe becomes more robust than Hayabusa against ion engine troubles.
Of course, when I was young, I tried to invent a new type of functional circuits, though I had to be engaged in studying other subjects, such as life of ordinary people working in a factory.
Interesting?
So, this is a patent-free Christmas story of tonight.
Bonne nuit, et de garder à l'esprit Hayabusa.
http://www.fukuchan.ac/music/j-senzen/getsugetsukasui.html