Deconvolution of target signature for a scene with bistatic impulse radiating antennas and a sphere
A model for an impulse radiating antenna (IRA) has been developed in WIPL-D. A scene using a bistatic pair of these IRAs is modeled with a sphere target and is simulated in the frequency domain. The input to the antenna is a Gaussian pulse, and the current on the receive antenna is plotted vs. frequency. This receiver response is proportional to the scattered field from the sphere. The frequency domain data are processed to give the time domain response. The objective of this work is to deconvolve the signature of the scatterer from the receiver transient response. Additional separate simulations for each scene component and electromagnetic interaction were needed and were performed using WIPL-D. The process is successful for this scene, which does not include a ground plane. The analysis of the simulated data and deconvolution of the target signature are done in Matlab.
Optimization of the TEM feed structure for four-arm reflector impulse radiating antennas
This paper considers the optimization of the feed arm geometry of four-arm crossed-coplanar plate impulse radiating antennas (IRAs) when the angular position and extent of the arms are taken as free parameters. Previously, optimization of this class of antenna considered only the symmetric case where the two pairs of crossed feed arms were perpendicular to each other. Comparison is made using the prompt aperture efficiency, and the results indicate that the efficiency of four-arm IRAs can be increased from /spl sim/25% for the perpendicularly crossed arms to /spl sim/35% for the optimum configuration. In addition to the optimization, the feed impedance of coplanar feeds is presented for general values of feed arm angle and plate width, and the optimum feed impedance is computed for each feed arm angle. The results can be used to design the optimal four-arm IRA with an arbitrary specified input impedance.
The Bastille: A History of a Symbol of Despotism and Freedom
This book is both an analysis of the Bastille as cultural paradigm and a case study on the history of French political culture. It examines in particular the storming and subsequent fall of the Bastille in Paris on July 14, 1789 and how it came to represent the cornerstone of the French Revolution, becoming a symbol of the repression of the Old Regime. Lusebrink and Reichardt use this semiotic reading of the Bastille to reveal how historical symbols are generated; what these symbols’ functions are in the collective memory of societies; and how they are used by social, political, and ideological groups.

To facilitate the symbolic nature of the investigation, this analysis of the evolving signification of the Bastille moves from the French Revolution to the nineteenth century to contemporary history. The narrative also shifts from France to other cultural arenas, like the modern European colonial sphere, where the overthrow of the Bastille acquired radical new signification in the decolonization period of the 1940s and 1950s. The Bastille demonstrates the potency of the interdisciplinary historical research that has characterized the end of this century, combining quantitative and qualitative approaches, and taking its methodological tools from history, sociology, linguistics, and cultural and literary studies.