Variational Methods have been frequently used for surface reconstruction and contour extraction (snakes). We present a surface reconstruction method where we assume the surface composed of two regions of di erent types of smoothness. One region of the surface models a \lake" (constant height region with uphill borders). It is surrounded by the other background region which is reconstructed usin...

In this paper a local problem of isometric embedding is studied. Here a sufficiant regular curve the initial curve is complemented to a surface of a prescribed line element an isometric embedding. While the local problem of isometric embedding is already in the focus of scientific research, solutions with a prescribed initial curve have not been considered by any other author this far. Therefor...

This paper tackles the problem of the computation of a planar polygonal curve from a digital planar curve, such that the digital data can be exactly retrieved from the polygonal curve. The proposed transformation also provides an analytical modelling of a digital plane segment as a discrete polygon composed of a face, edges and vertices. A dual space representation of lines and planes is used t...

A projective algebraic surface which is homeomorphic to a ruled surface over a curve of genus g ≥ 1 is itself a ruled surface over a curve of genus g. In this note, we prove the analogous result for projective algebraic manifolds of dimension 4 in case g ≥ 2.

The receiver operating characteristic (ROC) curve is an important tool to gauge the performance of classifiers. In certain situations of high-throughput data analysis, the data is heavily class-skewed, i.e. most features tested belong to the true negative class. In such cases, only a small portion of the ROC curve is relevant in practical terms, rendering the ROC curve and its area under the cu...

We analyze seismic data using multi-channel analysis of surface waves (MASW) to invert multi-mode surface-wave dispersion curves into 1D vertical shear-wave velocity profiles. The dispersion-curve patterns of the Rayleigh wave are imaged using conventional methods and the high-resolution linear radon transform (HRLRT). Comparison of these imaging techniques shows that the HRLRT provides higher ...

The normalform h= 0 of a curve (surface) is a generalization of the Hesse normalform of a line in R2 (plane in R3). It was introduced and applied to curve and surface design in recent papers. For determining the curvature of a curve (surface) defined via normalforms it is necessary to have formulas for the second derivatives of the normalform function h depending on the unit normal and the norm...

introduction: nowadays,  considerable developments  in  the field  of  radiotherapy have  been  achieved.  they  include  the  advances  made  in  the  equipments  and  treatment  planning  techniques  which  require  highly complex calculations. such achievements have made it possible to treat cancer patients not only  with  higher  radiation  dose  but  also  with  higher  precision  and  con...

During the process of designing smoothly curved forms, it is important to have methods available for the assessment of shape quality. The advent of computer graphics has made it possible to perform curve and surface interrogation without the construction of a physical model. Methods have relied on renderings, starting with wireframe representations, and increasing in sophistication to today’s h...