Global illumination is an important area of computer graphics, having direct applications in architectural visualization, lighting design and entertainment. Indirect illumination effects such as soft shadows, color bleeding, caustics and glossy reflections provide essential visual information about the interaction of different regions of the environment. Global illumination is a research area t...

Convolution/superposition software has been used to produce a library of photon pencil beam dose matrices. This library of pencil beams is designed to serve as a tool for both education and investigation in the field of radiotherapy optimization. The elegance of this pencil beam model stems from its cylindrical symmetry. Because of the symmetry, the dose distribution for a pencil beam from any ...

BACKGROUND AND PURPOSE New treatment techniques in radiotherapy employ increasing dose calculation complexity in treatment planning. For an adequate check of the results coming from a modern treatment planning system, clinical tools with almost the same degree of generality and accuracy as the planning system itself are needed. To fulfil this need we propose a photon pencil kernel parameterizat...

Researchers in non-photorealistic rendering have investigated the display of three-dimensional worlds using various display models. In particular, recent work has focused on the modeling of traditional artistic media and styles such as pen-and-ink illustration and watercolor painting. By providing 3D rendering systems that use these alternative display models users can generate traditional illu...

The use of paper and pencil tests for the selection of candidates and to identify individual differences should be approached cautiously because the interpretations of the tests can be very subjective. Although personal preferences do tend to become more stable as we grow older, they may vary from one day to the next. No one is an absolute extrovert or introvert; we all have tendencies toward o...

Neuroscience has advanced our understanding of the neurological basis of reading disability (RD). Yet, no functional imaging work has been reported on the twice-exceptional dyslexic: individuals exhibiting both non-verbal-giftedness and RD. We compared groups of reading-disabled (RD), non-verbally-gifted (G), non-verbally-gifted-RD (GRD), and control (C) adults on validated word-rhyming and spa...

To continue and expand upon the foundation provided by the recent flight of the NASA Scatterometer (NSCAT), NASA is developing the SeaWinds instrument which is scheduled to fly on the Quikscat mission in November 1998, and on the Second Japanese Earth Observation Satellite (ADEOS-11) to be launched in early 2000. In a significant design departure from previous “fan-beam” scatterometer systems, ...

Absfracf-We present a study of a matrix pencil method for estimating parameters (frequencies and damping factors) of exponentially damped and/or undamped sinusoids in noise. Comparison of this method to a polynomial method (SVD-Prony method) shows that the matrix pencil method and the polynomial method are two special cases of a matrix prediction approach but the pencil method i s more efficien...

This paper studies the problem of designing a rational Bézier developable surface pencil with a common isogeodesic, and provides an algorithm for the representation of complicated geometric models in industrial applications which need to satisfy that the shape surface can be developed and a given curve is geodesic. By employing the local Frenet orthonormal frame, the explicit expression of the ...

A model for beam customization with collimators and a range-compensating filter based on the phase-space theory for beam transport is presented for dose distribution calculation in the treatment planning of radiotherapy with protons and heavier ions. Independent handling of pencil beams in conventional pencil-beam algorithms causes unphysical collimator-height dependence in the middle of large ...