Deep Learning-Based Approach for Low Probability of Intercept Radar Signal Detection and Classification
JOURNAL OF COMMUNICATIONS TECHNOLOGY AND ELECTRONICS
Authors: Ghadimi, G.; Norouzi, Y.; Bayderkhani, R.; Nayebi, M. M.; Karbasi, S. M.
Abstract
Detection and classification of Low Probability of Interception (LPI) radar signals is one of the most important challenges in electronic warfare (EW), since there are limited methods for identifying these type of signals. In this paper, a radar waveform automatic identification system for detecting and classifying LPI radar is studied, and accordingly we propose a method based on deep learning networks to detect and classify LPI radar waveforms. To this end, the GoogLeNet architecture as one of the well-known convolutional neural networks (CNN) is utilized. We employ the Short Time Fourier Transform (STFT) for time-frequency analysis in order to construct the entry image for proposed method 1,2 (improved the GoogLeNet and AlexNet networks) to recognize offline training and online recognition. After the training procedure with the supervised data sets the proposed method 1,2 can detect and classify nine modulation types of LPI radar, including LFM, poly-phase (P1, P2, P3, P4) and poly-time (T1, T2, T3, T4) waveforms. The numerical results for proposed method 1, show considerable accuracies up to 98.7% at the SNR level of -15 dB, which outperforms the existing methods.
Electrophysiological evaluation of efficacy of clipping in thoracic sympathectomy: An experimental cadaveric study
TURK GOGUS KALP DAMAR CERRAHISI DERGISI-TURKISH JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
Authors: Salci, Hakan; Acar, Hilal; Taskapilioglu, Mevlut Ozgur; Melek, Huseyin; Bayram, Ahmet Sami
Abstract
Background: This study aims to examine the efficacy of clipping in thoracic sympathectomy based on electrophysiological evaluation and to investigate whether nerve conduction can be formed by collateral nerve extensions as a result of the clipping procedure to different levels of sympathetic nerve. Methods: Newly sacrificed six sheep hemithoraces were studied between August 2016 and October 2016. Thoracic sympathectomy was performed by clipping at T2, T3, T4, and T5 sympathetic chain levels and their branches. Electrophysiological studies were performed with an electromyography device and the filter range was 1 Hz with 20 mu V/D amplification. Signals were processed digitally; bipolar subdermal needle electrodes were used as stimulation and recording electrodes (emptyset 0.75 mm); and the ground electrode was placed in the intercostal muscle where the thoracic sympathectomy procedure would be performed. Results: Electrophysiological evaluations showed that clips placed on the main sympathetic chain branches and sympathetic nerve trunk prevented collateral impulse conduction and stimulated potentials were not recorded. However, sympathetic conduction continued at the same intensity after removal of the clips. Conclusion: Clipping of different regions of the sympathetic nerve provides electrophysiological blockage of the sympathetic nerve, and conduction continues after removal of the clips. However, the short- and long-term postoperative electrophysiological results after removal of the clips over the sympathetic nerve is still a question mark.