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Probability density estimation via an infinite Gaussian mixture model: application to statistical process monitoring
Author(s) -
Chen Tao,
Morris Julian,
Martin Elaine
Publication year - 2006
Publication title -
journal of the royal statistical society: series c (applied statistics)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.205
H-Index - 72
eISSN - 1467-9876
pISSN - 0035-9254
DOI - 10.1111/j.1467-9876.2006.00560.x
Subject(s) - mixture model , gaussian process , basis (linear algebra) , probability density function , mathematics , gaussian , process (computing) , limit (mathematics) , computer science , mixture distribution , density estimation , multivariate normal distribution , dirichlet process , statistics , algorithm , multivariate statistics , mathematical analysis , bayesian probability , physics , geometry , quantum mechanics , operating system , estimator
Summary. The primary goal of multivariate statistical process performance monitoring is to identify deviations from normal operation within a manufacturing process. The basis of the monitoring schemes is historical data that have been collected when the process is running under normal operating conditions. These data are then used to establish confidence bounds to detect the onset of process deviations. In contrast with the traditional approaches that are based on the Gaussian assumption, this paper proposes the application of the infinite Gaussian mixture model (GMM) for the calculation of the confidence bounds, thereby relaxing the previous restrictive assumption. The infinite GMM is a special case of Dirichlet process mixtures and is introduced as the limit of the finite GMM, i.e. when the number of mixtures tends to ∞. On the basis of the estimation of the probability density function, via the infinite GMM, the confidence bounds are calculated by using the bootstrap algorithm. The methodology proposed is demonstrated through its application to a simulated continuous chemical process, and a batch semiconductor manufacturing process.