On the basis of the survey of underground noise in Jinggezhuang and Donghuantuo mines, Kailuan Group, noise radiation intensity, noise propagation properties and noise frequency-spectrum characteristics of underground...On the basis of the survey of underground noise in Jinggezhuang and Donghuantuo mines, Kailuan Group, noise radiation intensity, noise propagation properties and noise frequency-spectrum characteristics of underground equipment were studied at different work conditions. The result indicates that the noise source intensity surpasses the noise limit requirement of 85 dBA completely. Nearly 70% noise sources exceed the noise limit of 90 dBA, and some are over 100 dBA. Noise attenua- tion in semi-free field environment on the ground is significantly different from underground far-field environment of noise source in coal mines. Noise of these regions, where staffs are long and highly concentrated, exceeds 85 dBA, the basic noise limit. The noise frequency-spectrum presents the wideband characteristics. Especially in the main frequency of the language communication 500, 1 000 and 2 000 Hz, the octave band of noise performs obviously.展开更多
We propose the use of intra-palm propagation signals as biometrics. The intra-palm propagation signal is a signal that is propagated in the shallow part of the skin of a palm. In this paper, we prepare dedicated measu...We propose the use of intra-palm propagation signals as biometrics. The intra-palm propagation signal is a signal that is propagated in the shallow part of the skin of a palm. In this paper, we prepare dedicated measuring devices and measure intra-palm propagation signals from twenty-one experimental subjects. We also evaluate the verification performance based on Euclidian distance or SVM （support vector machine）. The equal error rate in the case of SVM is aovroximatelv 24%.展开更多
Transmitter identification(TxID) technique is used to diagnose the operation status of radio transmitters in DTV distributed transmission network.A new TxID method for digital video broadcasting-handheld (DVB-H) syste...Transmitter identification(TxID) technique is used to diagnose the operation status of radio transmitters in DTV distributed transmission network.A new TxID method for digital video broadcasting-handheld (DVB-H) system is proposed.Watermark is embedded in the DVB-H signal to form the composite signal.According to watermarking theory we demonstrate the required signal level for watermarking signal to achieve given bit error probability under different circumstance.By selecting the reference pattern to generate watermarking signal,peak-to-average power ratio(PAPR) of the transmitted signal can be improved.Simulation results show that even in wireless situation the receiver can distinguish the watermarking signal with low embedding strength, and distortion to the host signal can also be ignored.展开更多
基金Supported by the National Natural Science Foundation of China （50974061） the Natural Science Foundation of Hebei Province （E2009001420）
文摘On the basis of the survey of underground noise in Jinggezhuang and Donghuantuo mines, Kailuan Group, noise radiation intensity, noise propagation properties and noise frequency-spectrum characteristics of underground equipment were studied at different work conditions. The result indicates that the noise source intensity surpasses the noise limit requirement of 85 dBA completely. Nearly 70% noise sources exceed the noise limit of 90 dBA, and some are over 100 dBA. Noise attenua- tion in semi-free field environment on the ground is significantly different from underground far-field environment of noise source in coal mines. Noise of these regions, where staffs are long and highly concentrated, exceeds 85 dBA, the basic noise limit. The noise frequency-spectrum presents the wideband characteristics. Especially in the main frequency of the language communication 500, 1 000 and 2 000 Hz, the octave band of noise performs obviously.
文摘We propose the use of intra-palm propagation signals as biometrics. The intra-palm propagation signal is a signal that is propagated in the shallow part of the skin of a palm. In this paper, we prepare dedicated measuring devices and measure intra-palm propagation signals from twenty-one experimental subjects. We also evaluate the verification performance based on Euclidian distance or SVM （support vector machine）. The equal error rate in the case of SVM is aovroximatelv 24%.
文摘Transmitter identification(TxID) technique is used to diagnose the operation status of radio transmitters in DTV distributed transmission network.A new TxID method for digital video broadcasting-handheld (DVB-H) system is proposed.Watermark is embedded in the DVB-H signal to form the composite signal.According to watermarking theory we demonstrate the required signal level for watermarking signal to achieve given bit error probability under different circumstance.By selecting the reference pattern to generate watermarking signal,peak-to-average power ratio(PAPR) of the transmitted signal can be improved.Simulation results show that even in wireless situation the receiver can distinguish the watermarking signal with low embedding strength, and distortion to the host signal can also be ignored.
