Shrinkage preliminary test estimation in exponential distribution under a precautionary loss function is considered. The minimum risk-unbiased estimator is derived and some shrinkage preliminary test estimators are proposed. We apply our results on censored data and records. The relative efficiencies of proposed estimators with respect to the minimum ‎risk-unbiased‎&...

It is well known that the matrix exponential function has practical applications in engineering and applied sciences. In this paper, we present some new explicit identities to the exponential functions of a special class of matrices that are known as central-symmetric $X$-form. For instance, $e^{mathbf{A}t}$, $t^{mathbf{A}}$ and $a^{mathbf{A}t}$ will be evaluated by the new formulas in this par...

Abstract Dirichlet series associated with the Poincaré attached to $$\mathrm{SL}(2,{{\mathbb {Z}}})$$ SL ( 2 , Z ) are introduced. Integral representations and transformation formulas given, which descr...

in this paper, wavelet collocation method has been used to solve nonlinear fin problem with temperature dependent thermal conductivity and heat transfer coefficient. thermal conductivity of fin materials varies any type so that we consider thermal conductivity as the general function of temperature.  here we consider three particular cases, where we assume that thermal conductivity is constant,...