A new electrical resistance tomography (ERT) system, based on the bi-directional current pulse technique, is de- veloped. Polarization effects at the electrodes are eliminated. During each half cycle of the excitation...A new electrical resistance tomography (ERT) system, based on the bi-directional current pulse technique, is de- veloped. Polarization effects at the electrodes are eliminated. During each half cycle of the excitation process, direct current (DC) is used as the excitation source and filtering is not needed. Moreover, using optimized data collection protocol, the number of current injections for a 16-electrode system is reduced to 14 for 104 independent readings of an image. Experimental results showed that the system is effective using the sensitivity coefficient algorithm for image reconstruction.展开更多
Impulse systems do not undergo the multi-path destructive interference that manifests itself as Rayleigh fading prevalent in continuous wave systems, but rather show up as delayed replications of the direct impulse. I...Impulse systems do not undergo the multi-path destructive interference that manifests itself as Rayleigh fading prevalent in continuous wave systems, but rather show up as delayed replications of the direct impulse. In this paper, the model for impulse signals propagation over a plane earth is proposed. The condition for direct pulse and its replication overlapping each other was investigated. The model described here also takes into account the polarization of the transmission signals and the reflection coefficient of the plane, which was always neglected by previous approaches. The simulation result shows that the path loss can be characterized as 3 zones with different path loss exponents as the distance between transmitter and receiver (T-R) increasing.展开更多
The issue of impulsive synchronization of the coupled chaotic laser plasma system is investigated. A new framework for impulsive synchronization of such chaotic systems is presented, which makcs the synchronization er...The issue of impulsive synchronization of the coupled chaotic laser plasma system is investigated. A new framework for impulsive synchronization of such chaotic systems is presented, which makcs the synchronization error system a linear impulsive control system. We derive some suffcient conditions for the synchronization of a laser plasma system via impulsive control with the varying impulsive intervals, which allows us to derive the impulsive synchronization law easily. To illustrate the effectiveness of the proposed results, two numerical examples are given.展开更多
基金Project (No. 2001BA701A46) supported by the Hi-Tech Researchand Development Program (863) of China
文摘A new electrical resistance tomography (ERT) system, based on the bi-directional current pulse technique, is de- veloped. Polarization effects at the electrodes are eliminated. During each half cycle of the excitation process, direct current (DC) is used as the excitation source and filtering is not needed. Moreover, using optimized data collection protocol, the number of current injections for a 16-electrode system is reduced to 14 for 104 independent readings of an image. Experimental results showed that the system is effective using the sensitivity coefficient algorithm for image reconstruction.
基金Sponsored by the Key Program of National Natural Science Foundation of China(Grant No60432040)
文摘Impulse systems do not undergo the multi-path destructive interference that manifests itself as Rayleigh fading prevalent in continuous wave systems, but rather show up as delayed replications of the direct impulse. In this paper, the model for impulse signals propagation over a plane earth is proposed. The condition for direct pulse and its replication overlapping each other was investigated. The model described here also takes into account the polarization of the transmission signals and the reflection coefficient of the plane, which was always neglected by previous approaches. The simulation result shows that the path loss can be characterized as 3 zones with different path loss exponents as the distance between transmitter and receiver (T-R) increasing.
基金The project supported by National Natural Science Foundation of China under Grant No. 60271019 and the Natural Science Foundation of Chongqing under Grant No. 8509
文摘The issue of impulsive synchronization of the coupled chaotic laser plasma system is investigated. A new framework for impulsive synchronization of such chaotic systems is presented, which makcs the synchronization error system a linear impulsive control system. We derive some suffcient conditions for the synchronization of a laser plasma system via impulsive control with the varying impulsive intervals, which allows us to derive the impulsive synchronization law easily. To illustrate the effectiveness of the proposed results, two numerical examples are given.
