Designs of cloaking devices and more general invisible objects have primarily applied the techniques of transformation optics and scattering cancellation to derive material structures that achieve the desired effects. In this Letter, we note that it is also possible to construct a broader class of invisible objects directly from the defining wave equation. The technique is demonstrated in a sca...

Simulating hand-drawn illustration can succinctly express information in a manner that is communicative and informative. We present a framework for an interactive direct stipple rendering of volume and surface-based objects. By combining the principles of artistic and scientific illustration, we explore several feature enhancement techniques to create effective, interactive visualizations of sc...

Illustrative visualization aims to effectively communicate a specific information. In traditional illustration the choice of appropriate styles and rendering techniques is guided by the intention of the artist. For illustrative volume visualizations it is difficult to specify the mapping between the 3D data and the visual representation. We introduce a layer between data and visual appearance t...

Clipping is a fast, common technique for resolving occlusions. It only requires simple interaction, is easily understandable, and thus has been very popular for volume exploration. However, a drawback of clipping is that the technique indiscriminately cuts through features. Illustrators, for example, consider the structures in the vicinity of the cut when visualizing complex spatial data and ma...

We present an illustrative visualization system for real-time and high quality rendering of clinical volumetric medical data. Our technique is inspired by a medical illustration technique for depicting contextual close-up views of selected regions of interest where internal anatomical features are rendered in high detail. Our method integrates four important components: decimation of original v...

We propose a technique based on human-performance models to evaluate the efficiency of shared workspaces, where individual and collaborative actions are intertwined. We apply the technique to an illustrative case and report that it: 1) facilitates the fine-grained analysis of workspace collaboration; 2) provides time predictions about collaborative actions; and 3) enables quantitative compariso...

The goal of our research was to compare and systematize several approaches non-parametric null hypothesis significance testing using computer-based statistical modeling. For teaching purposes, a model for simulation created. results were analyzed Fisher's angular transformation, Chi-square, Mann-Whitney, exact tests. Appropriate software created, allowing us recommend new illustrative materials...

We discuss and compare two alternative perturbation approaches for the calculation of the period of nonlinear systems based on the Lindstedt–Poincaré technique. As illustrative examples we choose one–dimensional anharmonic oscillators and the Van der Pol equation. Our results show that each approach is better for just one type of model considered here.

There have been significant developments in ultrasound technology in the last few years which have resulted in an increase in the clinical value of this technique. An illustrative case is presented of how ultrasound technology has been used in the intraoperative and postoperative period to evaluate graft patency and function in patients undergoing extracranial-intracranial bypass graft surgery.

A direct method for solving variational problems using Legendre wavelets is presented. An operational matrix of integration is first introduced and is utilized to reduce a variational problem to the solution of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of the technique. © 2000 IMACS. Published by Elsevier Science B.V. All rights reserved.