[历年数学建模优秀论文]m04.pdfVIP

Unique or not ? Fingerprint says “Yes!” ∼ Team #307 Page 1 of 23 Unique or not ? Fingerprint says “Yes!” Abstract It is hard to believe that everyone’s name is unique to himself. But “are your fingerprints unique to yourself?” many people will answer “yes”. In order to prove this problem, we create models to explain it. At first we create a simple and comprehensible model to quickly and coarsely estimate this problem with fingerprints patterns. It’s easy to see that our fingerprints vary in general patterns. There are commonly 9 patterns in our fingerprints. Assume that we can distinguish c kinds of fingerprints in a certain pattern for sampled population A . With the variety of parameter c and A , we get an interesting conclusion that even we can distinguish a huge amount of fingerprints in a certain pattern (c=1000 billion) for a local city’s population (A=30 million), the probability of two or more people have the same fingerprints, or similar exactly, is nearly 100%. To obtain an available model, we create an advanced model more strictly and precisely. The ridges and furrows in fingerprint have some similar characteristics. We select 3 kinds of minutiae points including their numbers, positions and directions and develop a statistical algorithm to calculate the uniqueness of fingerprints. The answer is that fingerprints are unique, as expected! Those two models are under a primary assumption that all characteristics of a given fingerprint can be well recognized. But, if the fingerprints at hand are mostly incomplete, polluted or distorted, odds of misidentificat