We address the delicate problem of offsetting polygonal meshes. Offsetting is important for stereolithography, NC machining, rounding corners, collision avoidance, and Hausdorff error calculation. We introduce a new fast, and very simple method for offsetting (growing and shrinking) a solid model by arbitrary distance r. Our approach is based on a hybrid data structure combining point samples, ...

The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system's behavior in simple geometries and in configurations encountered in clinical practice. The first series of t...

last year, hard-nosed scientists and art historians had a joint study day. The Wellcome Trust, the world's largest medical research charity, has recently been using some of its money to encourage collaboration of scientists and artists, through the Sci~Art competition. It's a laudable aim but the cynical, including this runner-up, suspect some winning entries have more to do with artists repres...

We give canonical forms for a general singular matrix pencil from which several observer design problems are easily solved. The geometrical basis of these forms is emphasized. Algorithms for the robust computation of the needed subspaces are given.

We provide a system that will serve as a high quality pencil media line reproduction agent for creating aesthetically pleasing lines that mimic human-drawn lines. The method avoids computationally expensive techniques and large storage space. The system is not intended to replace artists or illustration, but to provide a tool for users with no training to produce traditional images using a penc...

An automatic structure for the mapping class group of a surface of finite type was described in [M]. This document is intended as a practical guide to computations using a variant of this automatic structure, in the special case of a once-punctured, oriented surface S. As such, we shall try to be more descriptive and less theoretical than in [M], leaving the reader to consult [M] for detailed p...

Tapered nanopillar structures of different cross-sectional geometries including cone-, pencil-like, and stepwise are prepared from anodized aluminum oxide templates. The shape effect on the adhesion strength is investigated in experiments and simulation. Cone-shaped nanopillars are highly bendable under load and can recover after unloading, thus, warranting high adhesion strength, 34 N cm(-2) ....

We propose a numerically reliable approach for computing solutions of least McMillan order of linear equations with rational matrix coefficients. The main computational ingredients are the orthogonal reduction of the associated system matrix pencil to a certain Kronecker-like staircase form and the solution of a minimal dynamic cover design problem. For these computations we discuss numerically...