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Fuzzy Support Vector Machines. IEEE Transactions on Neural Networks,2002 Authors: Chun-Fu Lin and Sheng-De Presentation by Zhuang Wang . Outline. Introduction SVMs vs Fuzzy SVMs Experiments My figures Drawbacks of the paper. Introduction. Motivation:
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Fuzzy Support Vector Machines IEEE Transactions on Neural Networks,2002 Authors: Chun-Fu Lin and Sheng-De Presentation by Zhuang Wang
Outline • Introduction • SVMs vs Fuzzy SVMs • Experiments • My figures • Drawbacks of the paper
Introduction • Motivation: In many applications (eg. evaluation of credit risk), different data points give different contribution to the decision surface. • How? Treat each point differently. (Give each point a weight or fuzzy membership .)
SVMs vs. FSVMs • Traditional SVMs: To solve the optimal hyperplane problem: (treat each point equally)
SVMs vs. FSVMs (cont.) • Fuzzy SVMs: (treat each point differently) Difference: each data point is presented like this: (Xi,Yi,si ), where si is a fuzzy membership between [0, 1], New Problem is:
SVMs vs. FSVMs (cont.) • The optimal problem is different, but the solution is very similar. (only one difference) After reformulation, the problem can be transformed into:
Experiments • Data with time property Assign fuzzy membership according to the time data arrive in the system. • Two class with different weighting Select fuzzy membership as a function of respective class. • Use Class Center to Reduce the Effects of Outliers Assign fuzzy membership according to the distance to class center.
Drawbacks of the paper • Only toy datasets, no reallife datasets are used in experimental part. • The way to assign fuzzy membership to data points need to be improved.