This paper investigates the problem of local surface reconstruction and best fitting for planar surfaces from unorganized 3D point cloud data. Least Squares (LS), its equivalent Principal Component Analysis (PCA) and RANSAC are the three most popular techniques for fitting planar surfaces to 3D data. LS and PCA are sensitive to outliers and do not give reliable and robust parameter estimation. ...

since 3d medical images such as spect and mri are taken under different patients positioning and imaging parameters, interpretation of them, as reconstructed originally, does not provide an easy and accurate understanding of similarities and differences between them. the problem becomes more crucial where a clinician would like to map accurately region of interest from one study to the other, b...

This paper takes a systematic look at several techniques for calculating curvature of a surface that is represented by a triangular mesh. Both discrete curvature approximation techniques and surface fitting methods are considered. We develop new methods based on a surface fit using a natural surface parameterization, and by fitting a general equation for a conic as an implicit function. Another...

Co-channel interference is a major factor in limiting the capacity and link quality in cellular communications. As the co-channel interference is modeled by lognormal distribution, sum of the co-channel interferences of neighboring cells is represented by the sum of lognormal Random Variables (RVs) which has no closed-form expression. Assuming independent, identically distributed (iid) RVs, the...

Fitting a Gaussian curve to real settlement data is of practical use because the parameters that describe the curve, namely volume loss, maximum settlement and trough width, are conceptually easy to understand and can be compared at different locations and for different tunnel sizes, depths and construction methods. Where the magnitude of surface settlements is small, it can be difficult to obt...

Polarimetric target decomposition enables the interpretation of radar images more easily, mostly based on physical assumptions, i.e., fitting physically-based scattering models to the polarimetric SAR observations. However, the model-fitting result cannot be always successful. Particularly, the performance of model-fitting in sloping forests is still an open question. In this study, the effect ...

In this research, we proposed a new method to model complex range data using a parametric model. We first compute local surface curvatures by quadratic fitting of local surfaces, and then extract the curved surfaces and plane regions from the range data by examining the probability distribution of local surface curvatures. After extracting these regions, one shape may be divided into multiple r...