Koyin Chang

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To understand the impact of drinking and driving laws on drinking and driving fatality rates, this study explored the different effects these laws have on areas with varying severity rates for drinking and driving. Unlike previous studies, this study employed quantile regression analysis. Empirical results showed that policies based on local conditions must(More)
OBJECTIVES Chronic Obstructive Pulmonary Disease (COPD) is one of the fastest growing causes of death worldwide. However, few studies, if any, have been conducted that have investigated patient profiles in Asia. This paper analyzes patient willingness to pay (WTP) as a function of patient disease severity, health-related quality of life (HRQL), and smoking(More)
Segmenting lung fields in a chest radiograph is essential for automatically analyzing an image. We present an unsupervised method based on multiresolution fractal feature vector. The feature vector characterizes the lung field region effectively. A fuzzy c-means clustering algorithm is then applied to obtain a satisfactory initial contour. The final contour(More)
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