(Panel) Smooth Transition Regressions substantially gained in popularity due to their flexibility in modeling regression coefficients as homogeneous or heterogeneous functions of transition variables. In the estimation process, however, researchers typically face a trade-off in the sense that a...

(Panel) Smooth Transition Regressions substantially gained in popularity due to their flexibility in modeling regression coefficients as homogeneous or heterogeneous functions of transition variables. In the estimation process, however, researchers typically face a trade-off in the sense that a...

One of the basic questions of solar research is the nature of the Sun. We show here how the plasma nature of the Sun leads to the self-generation of solar activity. The release of magnetic, rotational, gravitational, nuclear energies and that of the gravity mode oscillations deviate from...

In sparse regression modeling via regularization such as the lasso, it is important to select appropriate values of tuning parameters including regularization parameters. The choice of tuning parameters can be viewed as a model selection and evaluation problem. Mallows’ Cp type criteria may be...

A new method of quantitative evaluation of teaching processes is elaborated. On the base of scores data, the method permits to evaluate efficiency of teaching within one group of students and comparative teaching efficiency in two or more groups. As basic characteristics of teaching efficiency...

This article on survey methodology addresses the problem of estimating degrees of freedom values from stratified multistage designs when a small number of primary sampling units (PSUs) are selected per stratum. Due to the small number of PSUs selected, the traditional Satterthwaite-based degrees...

For ridge regression the degrees of freedom are commonly calculated by the trace of the matrix that transforms the vector of observations on the dependent variable into the ridge regression estimate of its expected value. For a fixed ridge parameter this is unobjectionable. When the ridge...