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TRUST-TECH based expectation maximization for learning finite mixture models (2007)
| Content Provider | CiteSeerX |
|---|---|
| Author | Reddy, Chandan K. Chiang, Hsiao-Dong Rajaratnam, Bala |
| Abstract | The Expectation Maximization (EM) algorithm is widely used for learning finite mixture models despite its greedy nature. Most popular model-based clustering techniques might yield poor clusters if the parameters are not initialized properly. To reduce the sensitivity of initial points, a novel algorithm for learning mixture models from multivariate data is introduced in this paper. The proposed algorithm takes advantage of TRUST-TECH (TRansformation Under STability-reTaining Equilibria CHaracterization) to compute neighborhood local maxima on the likelihood surface using stability regions. Basically, our method coalesces the advantages of the traditional EM with that of the dynamic and geometric characteristics of the stability regions of the corresponding nonlinear dynamical system of the log-likelihood function. Two phases namely, the EM phase and the stability region phase, are repeated alternatively in the parameter space to achieve local maxima with improved likelihood values. The EM phase obtains the local maximum of the likelihood function and the stability region phase helps to escape out of the local maximum by moving towards the neighboring stability regions. Though applied to Gaussian mixtures in this paper, our technique can be easily generalized to any other parametric finite mixture model. The algorithm has been tested on both synthetic and real datasets and the improvements in the performance compared to other approaches are demonstrated. The robustness with respect to initialization is also illustrated experimentally. |
| File Format | |
| Journal | IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE |
| Language | English |
| Publisher Date | 2007-01-01 |
| Access Restriction | Open |
| Subject Keyword | Finite Mixture Model Expectation Maximization Local Maximum Stability Region Phase Stability Region Em Phase Corresponding Nonlinear Dynamical System Parametric Finite Mixture Model Greedy Nature Improved Likelihood Value Gaussian Mixture Real Datasets Initial Point Log-likelihood Function Neighborhood Local Maximum Likelihood Function Traditional Em Mixture Model Stability-retaining Equilibrium Characterization Poor Cluster Likelihood Surface Multivariate Data Novel Algorithm Parameter Space Neighboring Stability Region Geometric Characteristic |
| Content Type | Text |
| Resource Type | Article |
