A two-level preconditioning method for the solution of (locally) refined finite element schemes using triangle meshes is introduced. In the isotropic SPD case, it is shown that the condition number of the preconditioned stiffness matrix is bounded uniformly for all sufficiently regular triangulations. This is also verified numerically for an isotropic diffusion problem with highly discontinuous...

We present a method for computing a posteriori error bounds for piecewise linear approximate solutions of elliptic equations of monotone type. The method is based on a relation between a line integral on an edge of a triangle and volume integrals in the triangle.

Recent work has demonstrated that composite finite-elements provide an effective means for physically based modeling of deformable bodies. In this paper we present a number of highly effective improvements of previous work to allow for a high-performance and high-quality simulation of boundary surfaces of deformable bodies with changing topology, for instance, due to cuts and incisions. Startin...

This paper describes a novel method for constructing triangle meshes from noisy and non-uniformly distributed 3D points. It consists of two steps. (1) Noise point removal uses clustering algorithm and epipolar constraint method to identify and remove noise points from the 3D points. (2) Constructive polygonization algorithm interpolates cleaned 3D points to construct a triangle mesh of the obje...

Simulation of soft tissue deformation is a critical part of surgical simulation. An important method for this is finite element (FE) analysis. Models for FE analysis are typically derived by extraction of triangular surface meshes from CT or MRI image data. These meshes must fulfill requirements of accuracy, smoothness, compactness, and triangle quality. In this paper we propose new techniques ...

A constrained Delaunay triangle mesh method is presented to recover the surface from the three-dimensional unstructured boundary point cloud. The surfaces of different three-dimensional object models are recovered by this triangle mesh method. The radius of the tested cylinder model can be accurately estimated from the derived maximum principle curvature. The derived minimum principle curvature...

Unique patterns present in the wings of dragonflies and damselflies can be used to determine their family, genus, and species. A method for classifying dragonflies and damselflies using a particular pattern known as the triangle was developed using scanned images of the wings. Digital image processing techniques, such as image segmentation and feature detection, are used to determine properties...

BACKGROUND The aim of this study was to analyze the inter-, intraligamentous, and side-related patterns of sensory nerve endings in ankle ligaments. METHODS A total of 140 ligaments from 10 cadaver feet were harvested. Lateral: calcaneofibular, anterior-, posterior talofibular; sinus tarsi: lateral- (IERL), intermediate-, medial-roots inferior extensor retinaculum, talocalcaneal oblique and c...

Recently, fuzzy linear programming problems have been considered by many. In the literature of fuzzy linear programming several models are offered and therefore some various methods have been suggested to solve these problems. One of the most important of these problems that recently has been considered; are Fully Fuzzy Linear Programming (FFLP), which all coefficients and variables of the prob...

In many interval computation methods, if we cannot guarantee a solution within a given interval, it often makes sense to “inflate” this interval a little bit. There exist many different “inflation” methods. The authors of PASCAL-XSC, after empirically comparing the behavior of different inflation methods, decided to implement the formula [x−, x]ε = [(1 + ε)x− − ε · x, (1 + ε)x − ε · x−]. A natu...