Without measurement errors in predictors, discontinuity of a nonparametric regression function at unknown locations could be estimated using a number of existing approaches. However, it becomes a challenging problem when the predictors contain measurement errors. In this paper, an error-in-variables jump point estimator is suggested for a nonparametric generalized error-in-variables regression model. A major feature of our method is that it does not impose any parametric distribution on the measurement error. Its performance is evaluated by both numerical studies and theoretical justifications. The method is applied to studying the impact of Medicare Levy Surcharge on the private health insurance take-up rate in Australia.

We consider the problem of detecting jump location curves of regression surfaces when they are spatially blurred and contaminated pointwise by random noise. This problem is common in various applications, including equi-temperature surface estimation in meteorology and oceanography and edge detection in image processing. In the literature, most existing jump-detection methods are developed under the assumption that there is no blurring involved, or that the blurring mechanism described by a point spread function (psf) is completely specified. In this article, we propose four possible jump detectors, without imposing restrictive assumptions on either the psf or the true regression surface. Their theoretical and numerical properties are studied and compared. We also propose a new quantitative metric for measuring the performance of a jump detector. A data-driven bandwidth selection procedure via the bootstrap is suggested as well. This article has supplementary material online.

In a period starting around 2007, the Hand, Foot, and Mouth Disease (HFMD) became wide-spreading in China, and the Chinese public health was seriously threatened. To prevent the outbreak of infectious diseases like HFMD, effective disease surveillance systems would be especially helpful to give signals of disease outbreaks as early as possible. Statistical process control (SPC) charts provide a major statistical tool in industrial quality control for detecting product defectives in a timely manner. In recent years, SPC charts have been used for disease surveillance. However, disease surveillance data often have much more complicated structures, compared to the data collected from industrial production lines. Major challenges, including lack of in-control data, complex seasonal effects, and spatio-temporal correlations, make the surveillance data difficult to handle. In this article, we propose a three-step procedure for analyzing disease surveillance data, and our procedure is demonstrated using the HFMD data collected during 2008-2009 in China. Our method uses nonparametric longitudinal data and time series analysis methods to eliminate the possible impact of seasonality and temporal correlation before the disease incidence data are sequentially monitored by a SPC chart. At both national and provincial levels, our proposed method can effectively detect the increasing trend of disease incidence rate before the disease becomes wide-spreading.

This supplementary file contains a description of the roof/valley edge detection procedure, proofs of the theoretical results presented in Section 3 of the paper, and some simulation results about the proposed method.

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