标题：Local Composite partial Likelihood Estimation for Length-Biased and Right-Censored Data
Length-biased data are commonly encountered in applications ranging from economics, engineering and epidemiological cohort studies. Such data are also often subject to right censoring due to loss of follow-up or the end of study. The structure of length-biased data is different from that of traditional survival data and because the assumption of independent censoring is often violated in the presence of biased sampling and the assumed model for the underlying population is no longer satisfied for the observed data. In this paper we consider a proportional hazard model with varying coefficients for right-censored and length-biased data which allow one to examine the interact effect nonlinearly of covariates with an exposure variable. We proposed a local composite likelihood procedure for estimating the unknown coefficient functions in the model. The asymptotic properties of the resulting estimators are established. In addition, an extensive simulation study is conducted and a data se...