Volume 4 Issue 4 March 2006


Guest Comment: Set Theoretic Concepts in Computer Science and Engineering—A Connection between Mathematics and Computing



Dele Oluwade


College of Science & Technology, P.O. Box 20253, University of Ibadan, Ibadan, Oyo 200005 NIGERIA

A Joint Source-Channel Steganography Decoding Paradigm and It’s Implications on Capacity



Ishtiaq Saaem and Hong Man


Visual Information Environment Lab (VIEL), Department of Electrical and Computer Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030 USA


Steganography has become extremely popular lately as a means of achieving security for many multimedia applications. However, research on stego-attack mechanisms has also kept pace with this development. Robustness to such stego-attacks usually requires a compromise in stego-capacity. In this paper we propose a joint source-channel coding paradigm for attack robustness with small overhead. We test our framework using a least significant bit based embedding algorithm and random additive attacks. Our results lead us to believe that the joint source-channel coding paradigm has significant potential in this area.

Evaluating Arm Movement Imitation


Authors and Affiliations:

Alexandra Constantin
Baxter Hall, Williams College, Williamstown, Massachusetts 01267 USA
Maja J. Matarić
Computer Science Department, University of Southern California, Los Angeles, California 90089 USA


In this paper, we present a metric for assessing the quality of arm movement imitation. We develop a joint-rotational-angle-based segmentation and comparison algorithm that rates pairwise similarity of arm movement trajectories on a scale of 1-10. We describe an empirical study designed to validate the algorithm we developed, by comparing it to human evaluation of imitation. The results provide evidence that the evaluation of the automatic metric did not significantly differ from human evaluation.

Explicit Solutions of the Wave Equation on Three Dimensional Space-Times: Two Examples with Dirichlet Boundary Conditions on a Disk



Daniel Boykis and Patrick Moylan


Physics Department, The Pennsylvania State University, Abington College, Abington, Pennsylvania 19001 USA


We study solutions of the wave equation with circular Dirichlet boundary conditions on a flat two-dimensional Euclidean space, and we also study the analogous problem on a certain curved space which is a Lorentzian variant of the 3-sphere. The curved space goes over into the usual flat space-time as the radius R of the curved space goes to infinity. We show, at least in some cases, that solutions of certain Dirichlet boundary value problems are obtained much more simply in the curved space than in the flat space. Since the flat space is the limit R → ∞ of the curved space, this gives an alternative method of obtaining solutions of a corresponding problem in Euclidean space.