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Biometric Identification Francesc Serratosa Exercises of Part 1: Biometrics for Human Identification Week 1 1. Take the Bertillon measures from two people and fill the first table (in centimetres). Then, fill the second table with the Euclidean distances and decide which is the maximum threshold such that the four people are considered as different subjects. After that, suppose that Will West and William West were actually the same person as was thought at first. What are the minimum and maximum threshold values? Trait Will West William West Person 1 Person 2 1) Height (fig. 1) 178.5 177.5 2) Arm with (fig. 2) 187.0 188.0 3) Height seated (fig. 3) 91.2 91.3 4) Head width (fig. 4) 19.7 19.8 5) Head length (fig. 5) 15.8 15.9 6) Cheek width (fig. 6) 14.8 14.8 7) Right ear length (fig. 6) 6.6 6.5 8) Left foot length (fig. 7) 28.2 27.5 9) Third left finger length (fig. 8) 12.3 12.2 10) Small left finger length (fig. 8) 9.7 9.6 11) Left forearm length (fig. 9) 50.2 50.3 Distance Will West William West Person 1 Person 2 Will West 0 William West 0 Person 1 0 Person 2 0 2. Which is the percentage of revenues of the fingerprint trait with respect to the whole biometric features? And what is the second biometric characteristic with the highest revenues? 3. Revenues of biometric systems from 2007 to 2015 with respect to time can be easily modelled as a linear function. What is the equation of the line? If predictions hold, which value is estimated in 2020? Week 2 4. Explain the differences between the verification and recognition systems. When is the first used and when is the second used? The algorithms to compare biometric traits can be very expensive temporarily. For this reason, it is usual to use algorithms that deduce sub-optimal distances very fast but can fail to get the exact distance. In which cases is important to use a sub-optimal algorithm? 5. Explain in what consists the enrolment to a biometric system. Typically, in the enrolment systems, there is a responsible for verifying the data in a whole process of capturing biometric features. Why it is so important to verify that this process is done correctly? 6. What are the six processes related on the verification, identification and registration systems? 7. Describe a real application that uses an off-line system and another that uses an online system. 8. Explain the difference between the two possible types of queries: Positives and negatives. Describe a pair of real applications that are of two types