This paper presents some chain ratio-type estimators for estimating finite population variance using two auxiliary variables in two phase sampling set up. The expressions for biases and mean squared errors of the suggested classes of estimators are given. Asymptotic optimum estimators (AOE’s) in each class are identified with their approximate mean squared error formulae. The theoretical and em...

This paper considers a nonparametric varying coefficient regression model with longitudinal dependent variable and cross-sectional covariates. The relationship between the dependent variable and the covariates is assumed to be linear at a specific time point, but the coefficients are allowed to change over time. Two kernel estimators based on componentwise local least squares criteria are propo...

The main purpose of microarray studies is screening to identify differentially expressed genes as candidates for further investigation. Because of limited resources in this stage, prioritizing or ranking genes is a relevant statistical task in microarray studies. In this article, we develop 3 empirical Bayes methods for gene ranking on the basis of differential expression, using hierarchical mi...

Functional data analysis has become an important area of research due to its ability of handling high dimensional and complex data structures. However, the development is limited in the context of linear mixed effect models, and in particular, for small area estimation. The linear mixed effect models are the backbone of small area estimation. In this article, we consider area level data, and fi...

Coprime arrays enable Direction-of-Arrival (DoA) estimation of an increased number sources. To that end, the receiver estimates autocorrelation matrix a larger virtual uniform linear array (coarray), by applying selection or averaging to physical array's estimates, followed spatial-smoothing. Both and have been designed under no optimality criterion attain arbitrary (suboptimal) Mean-Squared-Er...

Estimation of the instantaneous frequency and its derivatives is considered for a harmonic signal with a time-varying phase and time-invariant amplitude. The asymptotic minimax lower bound is derived for the mean squared error of estimation provided that the phase is an arbitrary m-times piece-wise differentiable function of time. It is shown that this lower bound is different only in a constan...

The problem of scalar and vector quantization in conjunction with a noisy binary symmetric channel is considered. The issue is the assignment of the shortest possible distinct binary sequences to quantization levels or vectors so as to minimize the mean squared error caused by channel errors. By formulating the assignment as a matrix (or vector in the scalar case) and showing that the mean squa...