Quantitative Analyses and Development of aq-Incrementation Algorithm for FCM with Tsallis Entropy Maximization
Tsallis entropy is aq-parameter extension of Shannon entropy. By extremizing the Tsallis entropy within the framework of fuzzyc-means clustering (FCM), a membership function similar to the statistical mechanical distribution function is obtained. The Tsallis entropy-based DA-FCM algorithm was developed by combining it with the deterministic annealing (DA) method. One of the challenges of this method is to determine an appropriate initial annealing temperature and aqvalue, according to the data distribution. This is complex, because the membership function changes its shape by decreasing the temperature or by increasingq. Quantitative relationships between the temperature andqare examined, and the results show that, in order to changeuikqequally, inverse changes must be made to the temperature andq. Accordingly, in this paper, we propose and investigate two kinds of combinatorial methods forq-incrementation and the reduction of temperature for use in the Tsallis entropy-based FCM. In the proposed methods,qis defined as a function of the temperature. Experiments are performed using Fisher’s iris dataset, and the proposed methods are confirmed to determine an appropriateqvalue in many cases.