Sieb des Eratosthenes

Wir sollten die Wochen in der Uni das Sieb des Eratosthenes in Maple nachprogrammieren. Nach ein bisschen ueberlegen bin ich auf eine recht nette Loesung gestossen, die insgesamt 3 Zeilen umfasst :)

n := 100;
M := {`$`(2 .. n)};
for j in `$`(2 .. trunc(sqrt(n))) do
    M := `minus`(M, {seq(i, i ...
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Reverse Engineering a Payment System #2

i prepared two different card outputs (just excerpts) to compare them. The first card is a guestcard, which you can buy without beeing registered in the system. The part i left out, is a not encrypted and empty sector which is totaly unimportant. The card has the UID: aa257c3c which ...

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bullet time video #1

Today, Rene Krause suggested making a bullet time video from borrowed DSLRs cameras. There are several problems which have to be fixed:

  • Getting enough cameras together (24 upwards)
  • Syncronising the cameras to shoot at the exact moment
  • stitching the images into a videoclip

The first problem is kinda easy to ...

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birthday paradox modified

Not long ago, i wrote an article about the famous birthday paradox. Basically, it says: take an amount of people and calculate the possibility two of them have them same day as their birthday. The possibility is crazy high. Now the basic idea: We calculate the total amount of combination ...

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