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The proportional subdistribution hazards (PSH) model is popularly used to deal with competing risks data. Censored quantile regression provides an important supplement as well as variable selection methods due to large numbers of irrelevant covariates in practice. In this paper, we study variable selection procedures based on penalized weighted quantile regression for competing risks models, which is conveniently applied by researchers. Asymptotic properties of the proposed estimators, including consistency and asymptotic normality of non-penalized estimator and consistency of variable selection, are established. Monte Carlo simulation studies are conducted, showing that the proposed methods are considerably stable and efficient. Real data about bone marrow transplant (BMT) are also analyzed to illustrate the application of the proposed procedure.

2019年7月—2020年10月,通过样线法对庐山国家级自然保护区鸟类资源进行调查,共布设样线33条,记录到鸟类99种4 005只,隶属于12目37科,其中国家二级重点保护野生鸟类9种,江西省重点保护野生鸟类23种,留鸟69种,夏候鸟10种,冬候鸟19种,旅鸟1种,保护区鸟类分布新纪录9种。林地生境内鸟类多样性(3.42)和丰富度(10.74)最高,各生境均匀度相差较小。庐山国家级自然保护区鸟类丰富度与江西省其他森林生态系统类型保护区差异不显著。调查结果丰富了庐山国家级自然保护区鸟类资源基础资料,可为资源保护提供依据。