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Chaotic characteristics of electromagnetic emission signals during deformation and fracture of coal 被引量:8
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作者 NIE Bai-sheng HE Xue-qiu +2 位作者 LIU Fang-bin ZHU Cheng-wei WANG Ping 《Mining Science and Technology》 EI CAS 2009年第2期189-193,共5页
Electromagnetic emission(EME) is a kind of physical phenomenon accompanying the process of deformation and fracture of loaded coal and rock and it is of importance in quantitatively analyzing its characteristics.This ... Electromagnetic emission(EME) is a kind of physical phenomenon accompanying the process of deformation and fracture of loaded coal and rock and it is of importance in quantitatively analyzing its characteristics.This will reveal the process of deformation and fracture of coal and predicting dynamic disasters in coal mines.In this study,the G-P(Grassberger and Procaccia) algorithm,calculation steps of the(if only 1 dimension) correlation dimension of time series and the identification standards of chaotic signals are introduced.Furthermore,the correlation dimensions of EME and the acoustic emission(AE) signals of time series during deformation and fracture of coal bodies are calculated and analyzed.The results show that the time series of pulses number of EME and the time series of AE count rate are chaotic and that the saturation embedding dimensions of a K3 coal sample are,respectively,5 and 6.The results can be used to provide basic parameters for predicting of EME and AE time series. 展开更多
关键词 coal and rock electromagnetic emission correlation dimension chaotic characteristics
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Chaos generation by a hybrid integrated chaotic semiconductor laser 被引量:4
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作者 Ming-Jiang Zhang Ya-Nan Niu +6 位作者 Tong Zhao Jian-Zhong Zhang Yi Liu Yu-Hang Xu Jie Meng Yun-Cai Wang An-Bang Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第5期122-130,共9页
We design a hybrid integrated chaotic semiconductor laser with short-cavity optical feedback.It can be assembled in a commercial butterfly shell with just three micro-lenses.One of them is coated by a transflective fi... We design a hybrid integrated chaotic semiconductor laser with short-cavity optical feedback.It can be assembled in a commercial butterfly shell with just three micro-lenses.One of them is coated by a transflective film to provide the optical feedback for chaos generation while insuring regular laser transmission.We prove the feasibility of the chaos generation in this compact structure and provide critical external parameters for the fabrication by theoretical simulations.Rather than the usual changeless internal parameters used in previous simulation research,we extract the real parameters of the chip by experiment.Moreover,the maps of the largest Lyapunov exponent with varying bias current and feedback intensity Kap demonstrate the dynamic characteristics under different external-cavity conditions.Each laser chip has its own optimal external cavity length(L)and feedback intensity(Kap)to generate chaos because of the different internal parameters.We have acquired two ranges of optimal parameters(L=4 mm,0.12〈Kap〈0.2 and L=5 mm,0.07〈Kap〈0.12)for two different chips. 展开更多
关键词 chaotic dynamic characteristics integrated chaotic semiconductor laser short-cavity optical feedback extraction of internal parameters
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Nonlinear chaotic characteristic in leaching process and prediction of leaching cycle period
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作者 刘超 吴爱祥 +1 位作者 尹升华 陈勋 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第11期2935-2940,共6页
A laboratory leaching experiment with samples of different grades was carried out, and an analytical method of concentration of leaching solution was put forward. For each sample, respectively, by applying phase space... A laboratory leaching experiment with samples of different grades was carried out, and an analytical method of concentration of leaching solution was put forward. For each sample, respectively, by applying phase space reconstruction for time series of monitoring data, the saturated embedding dimension and the correlation dimension were obtained, and the evolution laws between neighboring points in the reconstructed phase space were revealed. With BP neural network, a prediction model of concentration of leaching solution was set up and the maximum error of which was less than 2%. The results show that there exist chaotic characteristics in leaching system, and samples of different grades have different nonlinear dynamic features; the higher the grade of sample, the smaller the correlation dimension; furthermore, the maximum Lyapunov index, energy dissipation and chaotic extent of the leaching system increase with grade of the sample; by phase space reconstruction, the subtle change features of concentration of leaching solution can be magnified and the inherent laws can be fully demonstrated. According to the laws, a prediction model of leaching cycle period has been established to provide a theoretical foundation for solution mining. 展开更多
关键词 leaching system phase space reconstruction chaotic characteristic leaching cycle period neural network prediction
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A Text Zero-Watermarking Algorithm Based on Chinese Phonetic Alphabets 被引量:13
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作者 ZHU Ping XIANG Guangli +3 位作者 SONG Wenna LI Ankang ZHANG Yuexin TAO Ran 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2016年第4期277-282,共6页
The text watermarking is a feasible method to protect the copyright from being copied and tampered. In this paper, a text zero-watermarking algorithm is proposed based on the connection between the Chinese characters ... The text watermarking is a feasible method to protect the copyright from being copied and tampered. In this paper, a text zero-watermarking algorithm is proposed based on the connection between the Chinese characters and the Chinese phonetic alphabets. According to the predefined interval threshold, the proposed algorithm extracts the characteristics of the text content by valuing on the basis of the custom of Chinese phonetic alphabets. After being chaotic transformed, the algorithm combines the text characteristics with the embedded watermarking information in the Chinese text. The experimental results show that the watermarking's capability of preventing tampering is up to 0.1%, which demonstrates the strong robustness and resistance to aggressive behavior of the algorithm. 展开更多
关键词 text watermarking Chinese phonetic alphabets chaotic transformation text characteristic
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