We present an explicit sixth order compact finite difference scheme for fast high accuracy numerical solutions of the two dimensional convection diffusion equation with variable coefficients. The sixth order scheme is based on the well-known fourth order compact scheme, the Richardson extrapolation technique, and an operator interpolation scheme. For a particular implementation, we use multisca...

Recently, the gradient based iterative algorithms have been widely exploited for finding the (leastsquares) solutions of the different kinds of the (coupled) linear matrix equations. Nevertheless, so far, the convergence of the propounded gradient based algorithms has been studied under the circumstance that the mentioned (coupled) linear matrix equations have a unique (least-squares) solution....

We introduce a Modiied Richardson-Lucy Algorithm for reducing data from the Subaru AO system. This new algorithm applies Magain's correct sampling approach to the Classical Richardson-Lucy algorithm. We have evaluated its performance for astronomical usage, appearance of the object and photometric accuracy, and compared our results to those obtained with a Classical Richardson-Lucy Algorithm.