in this work, hierarchical wo3 core-shell microspheres were synthesized via a facile template-free precipitation method. gas sensing properties of the synthesized powder to acetone and some other volatile organic compounds were comparatively investigated with commercial wo3 nanoparticles. the synthesized and commercial powders were characterized by x-ray diffraction, scanning electron microscop...

This paper introduces a novel shape representation which performs shape analysis in a hierarchical fashion using Gaussian and Laplacian pyramids. A background on hierarchical shape analysis is given along with a detailed explanation of the hierarchical method, and results are shown on natural contours. A comparison is performed between the new method and our proposed approach using Point Distri...

We consider the wave equation in a boundary integral formulation. The discretization in time is done by using convolution quadrature techniques and a Galerkin boundary element method for the spatial discretization. In a previous paper, we have introduced a sparse approximation of the system matrix by cutoff, in order to reduce the storage costs. In this paper, we extend this approach by introdu...