We investigate the propagation of errors through geometric transformations, such as reflections, rotations, similarity transformations, and projections, and also the scalar product of vectors. This means computing tolerance zones of points which undergo such transformations, if these points and the transformations themselves are given by toleranced input data.

This paper presents a new method for surface mesh simplification. Given an initial surface mesh (denoted as reference mesh), the goal is to reduce the number of mesh elements while preserving the geometric approximation as well as the shape quality of the resulting mesh. Two tolerance areas with respect to the reference mesh have been introduced to preserve the geometry of the surface. The refe...

The purpose of this research is to investigate a computer-aided approach to tolerance analysis for assemblies and mechanisms. A CAD system which can generate NURBS surfaces is used to produce imperfect-form, variant models. A method is developed for simulating the mating of these imperfect-form components by formulating surface mating relationships as a nonlinear programming problem. Using this...

The classiication problem is fundamental in the metrology of Geometric Tolerancing: given a part B, is it within some tolerance ? The \standard method-ology" for the classiication problem comprises three steps: sampling , algorithmic step and policy decision . The issues we examine are posed around this methodology, using a simple 1-dimensional problem as case study.

The use of edge based refinement in general, and Delaunay terminal edge refinement in particular are well established for planar meshing, but largely on a heuristic basis. In this paper, we present a series of theoretical results on the geometric mesh improvement properties of these methods. The discussion is based on refining a mesh to meet a specified angle tolerance.

We present an unstructured triangular mesh generation algorithm that approximates a set of mutually non-intersecting simple trimmed rational B-spline surface patches within a user specified geometric tolerance. The proposed method uses numerically robust interval geometric representations/computations and also addresses the problem of topological consistency (homeomorphism) between the exact ge...

We present an unstructured triangular mesh generation algorithm that approximates a set of mutually non-intersecting simple trimmed rational B-spline surface patches within a user speciied geometric tolerance. The proposed method uses numerically robust interval geometric representations/computations and also addresses the problem of topological consistency (homeomorphism) between the exact geo...

The aim of this study was to evaluate serum levels of C-reactive protein (CRP), adiponectin and leptin and their relationship with categories of glucose tolerance and body mass index (BMI) in a population with high prevalence of diabetes, the Brazilian Xavante Indians. A cross-sectional study was conducted among 938 Xavante Indians aged 20 years or more, from the Sangradouro and São Marcos rese...

BACKGROUND Epidemiologic evidence suggests that serum carotenoids are potent antioxidants and may play a protective role in the development of chronic diseases including cancers, cardiovascular disease, and inflammatory diseases. The role of these antioxidants in the pathogenesis of diabetes mellitus remains unclear. OBJECTIVE This study examined data from a cross-sectional survey to investig...

Laboratories that reported isolations of Streptococcus sanguis from blood cultures to the Communicable Disease Surveillance Centre (CDSC) Colindale were requested to submit strains to Bath Public Health Laboratory to allow the prevalence of penicillin tolerance within different biotypes of this species to be studied. One hundred and fifty one Streptococcus spp were received from 78 United Kingd...