2016 02 01

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Politecnico di Milano Facoltà di Ingegneria dell’Informazione Data Mining and Text Mining Tecniche di Apprendimento Automatico Prof. Pier Luca Lanzi & Ing. Daniele Loiacono February 1, 2016 NAME MATRICOLA Solve the following problems and write the answer inside the problem box. Answers must be clearly written. Pencils are not allowed. The midterm consists of 3 sheets of paper. It must be returned with all the 3 sheets. No any other sheet can be added. No sheet can be removed. This is a closed-book, closed-notes exam. Only non-programmable calculators are allowed. Notes/books/mobile phones are not allowed. If you are caught using forbidden material, the exam will immediately end and an RP grade will be recorded; then, your Data Mining exam will consist of an oral examination from then on. All the answers must be adequately motivated. Grades The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. Problem 1. (7 pts). Given the binary database below, representing a set of six transactions, apply the éclat algorithm with a min support of 3 (or 50%) Prof. Pier Luca Lanzi The Eclat Algorithm • Leverages the tidsets directly for support computation. • The support of a candidate itemset can be computed by intersecting the tidsets of suitably chosen subsets. • Given t(X) and t(Y) for any two frequent itemsets X and Y, ! then t(XY)=t(X)
t(Y) • And sup(XY) = |t(XY)| 28 Problem 1. (continued) Problem 2. (7 pts). Consider the data points below. Discuss the best possible outcome of applying kmeans, density-based clustering, CURE, and BFR to such data points. Use one picture…