In this notes, we summarize numerical methods for solving Stokes equations on rectangular grid, and solve it by multigrid vcycle method with distributive Gauss-Seidel relaxation as smoothing. The numerical methods we concerned are MAC scheme, nonconforming rotate bilinear FEM and nonconforming rotate bilinear FVM. 1. PROBLEM STATEMENT We consider Stokes equation (1.1) 8 >< >: μ ~ u +rp =~ f in ...

It is shown that the number of members, NA, and the linear radius of the Abell clusters at z < 0.18 increase with redshift. The increase is caused by observational selection: the number of rich and large clusters is small in the nearby small volume of space, while poor and small clusters are not detected at high distances. Besides, the numbers of clusters with different ellipticities are about ...

A procedure is proposed that, given any rotatingdevice to support a camera, places the camera’s center of projection to within a tenth of a millimeter from the axis of the rotating device, even with wide angle lenses with severe distortion. Results are experimentally validated by checking that all the camera projection centers as computed through an off-theshelf calibration method are at the sa...

A robust method for local image region feature description based on step sector statistics is proposed in this paper. The means and the standard deviations along the radial direction of the circle image region are extracted through the sector masks, and the rearrangement of these statistics makes this image region description method rotation-robust. The proposed description method is applied in...