Abstract In order to make full use of the topographic map with DWG format and construct 3D terrain model, a new 3D terrain model generation algorithm based on conversion technology is put forward. Firstly, by processing the topographic map with DWG format, we can get the standardized data which can be stored in spatial database. Secondly, the elevation points and the elevation data note text ar...

A novel derivation is presented of T. Kohonen's topographic mapping training algorithm (Self-Organization and Associative Memory, 1984), based upon an extension of the Linde-Buzo-Gray (LBG) algorithm for vector quantizer design. Thus a vector quantizer is designed by minimizing an L(2) reconstruction distortion measure, including an additional contribution from the effect of code noise which co...

PURPOSE To investigate the effect of pterygium surgery on corneal topography and contrast sensitivity. PATIENT AND METHODS The IRB approved this prospective, nonrandomized, self-controlled study. Computerized videokeratography (Orbscan II) was performed in 36 patients with primary pterygia, both before and 1 month after pterygium excision with limbal-conjunctival autografting. The topographic...

The mapping function w = k log(z + a) is a widely accepted approximation to the topographic structure of primate V1 foveal and parafoveal regions. A better model, at the cost of an additional parameter, captures the full field topographic map in terms of the dipole map function w = k log[(z + a)/(z + b)]. However, neither model describes topographic shear since they are both explicitly complex-...

Topographic and overcomplete representations of natural images/videos are important problems in computational neuroscience. We propose a new method using both topographic and overcomplete representations of natural images, showing emergence of properties similar to those of complex cells in primary visual cortex (V1). This method can be considered as an extension of model in Hyvärinen et al. [T...

The effect of bottom topography H on the barotropic transport in a periodic zonal channel is studied. An asymptotic approximation is found for the zonal transport on anf-plane and a P-plane when all f/H isolines are blocked by the zonal walls. It is shown that to leading order, the zonal channel transport is independent of friction. In this it is similar to the Sverdrup transport in a basin. To...

This paper presents the preliminary results of an extensive parametric study on seismic response of two-dimensional semi-sine shaped hills to vertically propagating incident P- and SV-waves. Clear perspectives of the induced diffraction and amplification patterns are given by investigation of time-domain and frequency-domain responses. It is shown that site geometry, wave characteristics , and ...