We construct and analyze a new family of quadrangular (in two dimensions) or cubic (in three dimensions) mixed finite elements for the approximation of elastic wave equations. Our elements lead to explicit schemes (via mass lumping), after time discretization, including in the case of anisotropic media. Error estimates are given for these new elements.

A kind of novel pillar (used to support a windshield) has been designed to replace the conventional ones used in all sorts of vehicles. The prominent advantage of such a pillar is that it appears invisible so that the blind spots caused by A, B, C and D pillars will be diminished to a large extent or even eliminated completely. Therefore, the driver’s view is enlarged considerably. An intrinsic...

Arpylorus antiquus, erected by Calandra (1964), was isolated from Upper Silurian sedimentary rocks from the Mechiguig-1 borehole in southern Tunisia, with other palynomorphs. The folded vesicle and the quadrangular form of the aperture breaks down into plate-like fragments, resembling the tabulation of dinoflagellates. The presence of these elements, have been used to interpret A. antiquus as a...

A new species, Larinus berti sp. n. is described from Morocco and assigned to subgenus Cryphopus Petri, 1907 (Curculionidae: Lixinae; Lixini). Diagnostic characters of the new species are large size, elongate-ovate body, bisulcate sub-quadrangular rostrum, triangularly raised dorsum of rostrum, flat subgena and submentum, Y-shaped apodeme of sternite VIII of female and thin nodulus of spermatheca.

In this paper, we develop a finite volume element method with affine quadratic bases on right quadrangular prismmeshes for three-dimensional elliptic boundary value problems. The optimal H1-norm error estimate of second order accuracy is proved under certain assumptions about themeshes. Numerical results are presented to illustrate the theoretical analysis. © 2008 Elsevier B.V. All rights reser...

We introduce a new method to compute conformal parameterizations using a recent definition of discrete conformity, and establish a discrete version of the Riemann mapping theorem. Our algorithm can parameterize triangular, quadrangular and digital meshes. It can be adapted to preserve metric properties. To demonstrate the efficiency of our method, many examples are shown in the experiment section.

In this paper, we regard a space-time block of video data as a piecewise-linear 3-manifold, and we interpret video segmentation as the computation of the Morse-Smale complex for the block. In the generic case, this complex is a decomposition of space-time data into 3-dimensional cells shaped like crystals, and separated by quadrangular faces. The vertices of these are Morse critical points. In ...

In this paper, we regard a space-time block of video data as a piecewise-linear 3-manifold, and we interpret video segmentation as the computation of the Morse-Smale complex for the block. In the generic case, this complex is a decomposition of space-time data into 3-dimensional cells shaped like crystals, and separated by quadrangular faces. The vertices of these are Morse critical points. In ...