The analysis of spatially correlated binary data observed on lattices is an interesting topic that catches the attention of many scholars of different scientific fields like epidemiology, medicine, agriculture, biolog...The analysis of spatially correlated binary data observed on lattices is an interesting topic that catches the attention of many scholars of different scientific fields like epidemiology, medicine, agriculture, biology, geology and geography. To overcome the encountered difficulties upon fitting the autologistic regression model to analyze such data via Bayesian and/or Markov chain Monte Carlo (MCMC) techniques, the Gaussian latent variable model has been enrolled in the methodology. Assuming a normal distribution for the latent random variable may not be realistic and wrong, normal assumptions might cause bias in parameter estimates and affect the accuracy of results and inferences. Thus, it entails more flexible prior distributions for the latent variable in the spatial models. A review of the recent literature in spatial statistics shows that there is an increasing tendency in presenting models that are involving skew distributions, especially skew-normal ones. In this study, a skew-normal latent variable modeling was developed in Bayesian analysis of the spatially correlated binary data that were acquired on uncorrelated lattices. The proposed methodology was applied in inspecting spatial dependency and related factors of tooth caries occurrences in a sample of students of Yasuj University of Medical Sciences, Yasuj, Iran. The results indicated that the skew-normal latent variable model had validity and it made a decent criterion that fitted caries data.展开更多
针对超像素分割算法中普遍存在的过分割问题,结合Mean Shift算法和非参数贝叶斯聚类模型,提出了一种新的图像分割算法MS-BRM(Mean Shift based Bayesian Region Merging)。首先,利用Mean Shift算法对图像进行超像素分割,然后根据非参数...针对超像素分割算法中普遍存在的过分割问题,结合Mean Shift算法和非参数贝叶斯聚类模型,提出了一种新的图像分割算法MS-BRM(Mean Shift based Bayesian Region Merging)。首先,利用Mean Shift算法对图像进行超像素分割,然后根据非参数贝叶斯聚类模型,融合超像素的空间信息,提出一种区域合并策略对超像素进行合并,得到了最终的分割结果。实验结果表明,MS-BRM算法改善了超像素的过分割问题,对图像进行分割的结果保留了图像的边界信息,更加符合人类视觉的判断结果。展开更多
文摘The analysis of spatially correlated binary data observed on lattices is an interesting topic that catches the attention of many scholars of different scientific fields like epidemiology, medicine, agriculture, biology, geology and geography. To overcome the encountered difficulties upon fitting the autologistic regression model to analyze such data via Bayesian and/or Markov chain Monte Carlo (MCMC) techniques, the Gaussian latent variable model has been enrolled in the methodology. Assuming a normal distribution for the latent random variable may not be realistic and wrong, normal assumptions might cause bias in parameter estimates and affect the accuracy of results and inferences. Thus, it entails more flexible prior distributions for the latent variable in the spatial models. A review of the recent literature in spatial statistics shows that there is an increasing tendency in presenting models that are involving skew distributions, especially skew-normal ones. In this study, a skew-normal latent variable modeling was developed in Bayesian analysis of the spatially correlated binary data that were acquired on uncorrelated lattices. The proposed methodology was applied in inspecting spatial dependency and related factors of tooth caries occurrences in a sample of students of Yasuj University of Medical Sciences, Yasuj, Iran. The results indicated that the skew-normal latent variable model had validity and it made a decent criterion that fitted caries data.
文摘针对超像素分割算法中普遍存在的过分割问题,结合Mean Shift算法和非参数贝叶斯聚类模型,提出了一种新的图像分割算法MS-BRM(Mean Shift based Bayesian Region Merging)。首先,利用Mean Shift算法对图像进行超像素分割,然后根据非参数贝叶斯聚类模型,融合超像素的空间信息,提出一种区域合并策略对超像素进行合并,得到了最终的分割结果。实验结果表明,MS-BRM算法改善了超像素的过分割问题,对图像进行分割的结果保留了图像的边界信息,更加符合人类视觉的判断结果。
