Sciweavers

SDM
2010
SIAM

Exact Passive-Aggressive Algorithm for Multiclass Classification Using Support Class

13 years 11 months ago
Exact Passive-Aggressive Algorithm for Multiclass Classification Using Support Class
The Passive Aggressive framework [1] is a principled approach to online linear classification that advocates minimal weight updates i.e., the least required so that the current training instance is correctly classified. While the PA framework allows integration with different loss functions, it is yet to be combined with a multiclass loss function that penalizes every class with a score higher than the true class. We call the method of training the classifier with this loss function the Support Class Passive Aggressive Algorithm. In order to obtain a weight update formula, we solve a quadratic optimization problem by using multiple constraints and arrive at a closed-form solution. This lets us obtain a simple but effective algorithm that updates the classifier against multiple classes for which an instance is likely to be mistaken. We call them the support classes. Experiments demonstrated that our method improves the traditional PA algorithms.
Shin Matsushima, Nobuyuki Shimizu, Kazuhiro Yoshid
Added 29 Oct 2010
Updated 29 Oct 2010
Type Conference
Year 2010
Where SDM
Authors Shin Matsushima, Nobuyuki Shimizu, Kazuhiro Yoshida, Takashi Ninomiya, Hiroshi Nakagawa
Comments (0)