Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery either in real-time or ...

Protecting signals is one of the main tasks in information transmission. A large number of different methods have been employed since many centuries ago. Most of them have been based on the use of certain signal added to the original one. When the composed signal is received, if the added signal is known, the initial information may be obtained. The main problem is the type of masking signal em...

Due to their potential applications for optical communications, data storage, and electrooptical signal processing, molecules with nonlinear optical (NLO) properties have been extensively investigated.’ As part of our interest in porphyrins and metalloporphyrins as photoresponsive2 and field-responsive material^,^ we have synthesized a series of “push-pull” porphyrins containing both donor and ...

The electric birefringence technique was used to investigate the steady-state birefringence, the orientational relaxation time, and the orientation mechanism of pig heart mitochondrial F1 adenosine-5'-triphosphatase (F1-ATPase). The electrooptical properties of this enzyme in solution were studied as functions of pH, protein concentration, and applied electric field. The F1-ATPase exhibits a su...

A new bent-core mesogen combining a 4-cyanoresorcinol unit with two terephthalate based rod-like wings and terminated by two long alkyl chains, was synthesized and investigated by DSC, XRD, optical, electrooptical and dielectric methods. A series of liquid crystalline phases in the unique sequence SmA-SmA(P)-SmCPR-(M1/SmCPα)-SmCsPA-SmCPA-SmCaPA, mainly distinguished by the degree and mode of co...

This thesis presents a comprehensive study of the role of the fiber replicator in electrooptical systems. In the all fiber optical diagnostic system for the National Ignition Facility‟s DANTE data acquisition system running at 1550nm, the 8× fiber replicator was used to increase the SNR (Signal to Noise Ratio) of single-shot, electrical pulse measurements. In the system, Mach-Zehnder modulators...

this study sought to investigate the impact of teaching speech acts and role relations through authentic audio-taped and video-taped materials on the level of iranian efl learners’ pragmatic competence. to this end, 55 intermediate learners were ed and randomly assigned to two experimental groups: the audio-taped group and the video-taped group. during the treatment, the audio-taped group recei...