We have developed an improved recombination calculation of H, He i, and He ii in the early universe that involves a line-by-line treatment of each atomic level. We find two major differences compared with previous calculations. First, the ionization fraction xe is approximately 10% smaller for redshifts &800 because of nonequilibrium processes in the excited states of H. Second, He i recombinat...

a frequency-wavenumber-domain formulation is presented in this paper for calculation of the green's functions and wave propagation modes in a stratified fluid body underlain by a layered viscoelastic soil medium. the green's functions define the solid and fluid displacements and fluid pressures due to uniform disk loads acting in either the soil or fluid media. the solution is in the frequency ...

We introduce an open-source MATLAB software package, named Crazyseismic, for passive seismic data preprocessing. Built-in core functions such as seismic phase travel-time calculation and multichannel cross correlation significantly improve the efficiency of data processing. Compared with conventional command-line-style toolboxes, all functions in Crazyseismic are embedded in one single graphic ...

This paper proposes a method of polarimetric synthetic aperture radar (PolSAR) image classification using improved superpixel segmentation and manifold learning. Firstly, a 27-dimension polarimetric feature space is extracted by simple arithmetic operations of polarimetric parameters and polarimetric target decomposition. Secondly, Laplacian Eigenmap (LE) algorithm is used to reduce the dimensi...

this paper is a slightly revised version of an introduction into singularity theory corresponding to a series of lectures given at the ``advanced school and conference on homological and geometrical methods in representation theory'' at the international centre for theoretical physics (ictp), miramare - trieste, italy, 11-29 january 2010. we show how to associate to a triple of positive integer...