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Parameters estimation for mixture of double generalized linear models
YUAN Qiao-li, WU Liu-cang, DAI Lin
Applied Mathematics A Journal of Chinese Universities, 2017, 32(3): 267-276.
In applications, there are many different statistical characteristics among diverse categories, so it is very necessary to study the heterogeneous population. This paper is based on the existence of the first order and second order moments of the distribution function, and the mixture of double generalized linear models is used to build mean and variance models in different population. After constructing the extended quasi-likelihood and pseudo-likelihood functions, the EM algorithm is used to estimate the mean parameter, dispersion parameter and mixture proportion. Finally, a Monte Carlo experiment and a real example prove that the model and the method are effective.
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Multi-atlas image segmentation for the low-resolution medical images
HE Guang-hua, ZHU Han-can, LIANG Ke-wei
Applied Mathematics A Journal of Chinese Universities, 2017, 32(3): 371-378.
Due to the high segmentation accuracy and robustness, the multi-atlas based image segmentation method is currently a hot topic. It consists of two main components which are the image registration and the label fusion. The most of current multi-atlas based image segmentation methods consider the situation that the atlas images and the target image have the same resolution. But, we will always obtain the low-resolution target images because of the restriction on the acquisition time and collecting equipment. On the other hand, the atlases are generated before the target images, and we often use high-resolution images to obtain high-resolution atlases. Since the registration from high-resolution atlases to the low-resolution target image may not obtain the exact results, the accuracy of the multi-atlas based image segmentation methods will be reduced when applied to segment the low-resolution target images. In order to solve this problem, we present an accurate and robust image segmentation method for low-resolution target images by combining the advantages of the image super-resolution method and the multi-atlas segmentation method. The experiment results show that the proposed method significantly improves the accuracy of the original multi-atlas based image segmentation method.
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13 articles
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