A method of ray tracing for free-form optical surfaces has been developed. The ray tracing through such surfaces is based on Delaunay triangulation of the discrete data of the surface and is related to finite-element modeling. Some numerical examples of applications to analytical, noisy, and experimental free-form surfaces (in particular, a corneal topography map) are presented. Ray-tracing res...

We present an extension of the fast beam-tracing method presented in the work of Antonacci et al. (2008) for the simulation of acoustic propagation in reverberant environments that accounts for diffraction and diffusion. More specifically, we show how visibility maps are suitable for modeling propagation phenomena more complex than specular reflections. We also show how the beam-tree lookup for...

The goal of ray tracing is to create images that are as accurate to real life as possible. Unfortunately, attaining this goal typically requires an extremely large amount of processing time. In this paper I propose a method for creating accurate soft shadows using graphics hardware to accelerate the process.

This paper presents a fast ray tracing procedure based on triangular division of the propagation environments. Unlike some accelerating methods based on pre-establishment of visibility, this method does not need the position information of base station and/or receiving antennas and is thus more general. Although the triangulation is in a two-dimensional plane, this method is suitable for three-...

Introduction Weapons tracing is a set of methods used to identify weapons and ammunition and track their origins. It has an established role in criminal investigations, where it is typically used not only to prove a firearm-related offence, but also to uncover the source of illicit supplies to criminals. By contrast, weapons tracing in conflict and post-conflict situations—for example, by peace...

Monitoring and troubleshooting distributed systems is notoriously di›cult; potential problems are complex, varied, and unpredictable. e de-factomonitoring and diagnosis tools at our disposal today – logs, counters, and metrics – have two important limitations: what gets recorded is dened a priori, and the information is recorded in a componentor machine-centric way, making it extremely hard to...

A traitor tracing scheme is a multi-receiver encryption scheme where malicious receiver coalitions aiming at building pirate decryption devices are deterred by the existence of a tracing algorithm: Using the pirate decryption device, the tracing algorithm can recover at least one member of the malicious coalition. All existing traitor tracing schemes rely either on rather inefficient generic co...

Two experiments were conducted to compare variation between 2 tracing methods in measuring cross-sectional lumen area of the caudal artery in 5 beef heifers on 3 different dates (Exp. 1) and to compare tracing methods in detecting changes in artery lumen area after 5 heifers were switched from a diet containing nonendophyte-infected tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] seed t...

Cell lineage tracing is a fundamental digital image processing tool for developmental biologists to probe the roles of cell differentiation, cell adhesion, and cell movement among other biophysical principles, in developmental programs. In this project I create an extension of cell lineage tracingtissue fate mapping or tissue lineage tracing. Tissue lineage tracing is useful for observing bioph...

Monte Carlo ray tracing programs are now being used to solve many optical analysis problems in which the entire optomechanical system must be considered. In many analyses, it is desired to consider the effects of diffraction by mechanical edges. Smoothly melding the effects of diffraction, a wave phenomenon, into a ray-tracing program is a significant technical challenge. This paper discusses t...