日期：2020年12月18日（周五）

时间：15：00（下午三点）

地点：理科楼B311

汇报人：18级王珊珊

论文题目：

《An ECG Signal De-Noising Approach Based on Wavelet Energy and Sub-Band Smoothing Filter》

论文简介：

Electrocardiographic (ECG) signal is essential to diagnose and analyse cardiac disease. However, ECG signals are susceptible to be contaminated with various noises, which affect the application value of ECG signals. In this paper, we propose an ECG signal de-noising method using wavelet energy and a sub-band smoothing filter. Unlike the traditional wavelet threshold de-noising method, which carries out threshold processing for all wavelet coefficients, the wavelet coefficients that require threshold de-noising are selected according to the wavelet energy and other wavelet coefficients remain unchanged in the proposed method. Moreover, The sub-band smoothing filter is adopted to further de-noise the ECG signal and improve the ECG signal quality. The ECG signals of the standard MIT-BIH database are adopted to verify the proposed method using MATLAB software. The performance of the proposed approach is assessed using Signal-To-Noise ratio (SNR), Mean Square Error (MSE) and percent root mean square difference (PRD). The experimental results illustrate that the proposed method can effectively remove noise from the noisy ECG signals in comparison to the existing methods.

录用期刊：Applied Sciences

论文题目：

《An efficient ECG denoising method based on empirical mode decomposition, sample entropy and improved threshold function》

论文简介：

Since the ECG signal can easily be affected by various types of noises while being recorded, which decreases the accuracy of subsequent diagnosis. Therefore, the efficient denoising of ECG signals has become an important research topic. This method can better remove the noise of ECG signal and provide better diagnosis service for computer-based automatic medical system. The proposed work includes three stages of analysis: (1) EMD is used to decompose the signal，and according to the sample entropy of each order IMF following EMD decomposition, the order of IMFs denoised is determined; (2) after which the new threshold function is adopted to denoise these IMFs; (3) Finally, the signal is reconstructed and smoothed. The proposed method solves the shortcoming of discarding the first-order IMF directly in traditional EMD denoising, and improves the traditional soft and hard threshold function, and proposes a new threshold denoising function. We further conduct simulation experiments of ECG signals from the MIT-BIH database, in which three types of noise are simulated: Gaussian white noise, electromyogram (EMG) and power line interference. It is thereby proven that the proposed method is robust to a variety of noise types. In addition, we analyze the effectiveness of the proposed method under different input SNR with reference to improving SNR () and mean square error (MSE), then compare the denoising algorithm proposed in this paper with previous ECG signal denoising techniques. The results showed that the denoising method proposed in this paper had a higher  and a lower MSE. Qualitative and quantitative studies demonstrate that the proposed algorithm is a good ECG signal denoising method.

录用期刊：Wireless Communications and Mobile Computing

汇报人：18级乾帅

论文题目：

《A New 4D Four-Wing Memristive Hyperchaotic System: Dynamical Analysis, Electronic Circuit Design, Shape Synchronization and Secure Communication》

论文简介：

In this paper, a simple four-wing chaotic attractor is first proposed by replacing the constant parameters of the Chen system with a periodic piecewise function. Then, a new 4D four-wing memristive hyperchaotic system is presented by adding a flux-controlled memristor with linear memductance into the proposed four-wing Chen system. The memristor mathematical structure model is simple and easy to implement. Dynamical analysis and numerical simulation of the memristive hyperchaotic system are carried out. Then, the electronic circuit of the hyperchaotic system is designed and implemented. The results of numerical simulation are in good agreement with the electronic circuit experiment. In addition, shape synchronization control for the 4D four-wing memristive hyperchaotic system is realized, and a communication system is designed by using the shape synchronization method. Finally, secure signal masking application is implemented on Matlab platform. In the developed secure communication scheme, the information signal overlaps with the chaotic masking signal, which improves the security of the system.

录用期刊：International Journal of Bifurcation and Chaos

论文题目：

《Pseudorandom Number Generator Based on Three Kinds of Four-Wing Memristive Hyperchaotic System and Its Application in Image Encryption》

论文简介：

In this paper, we propose a method to design pseudorandom number generator (PRNG) using three kinds of four-wing memristive hyperchaotic systems (FWMHSs) with different dimensions as multi-entropy sources. The principle of this method is to obtain pseudorandom numbers with good randomness by coupling XOR operation on the three kinds of FWMHSs with different dimensions. In order to prove its potential application in secure communication, the security of PRNG based on this scheme is analyzed from the perspective of cryptography. In addition, PRNG has passed the NIST 800.22 and ENT test, which shows that PRNG has good statistical characteristics. Finally, an image encryption algorithm based on PRNG is adopted. In the encryption algorithm, the optimized Arnold matrix scrambling method and the diffusion processing based on XOR are used to obtain the final encrypted image. Through the evaluation of encryption performance, it is concluded that there is no direct relationship between pristine image and encrypted image. The results show that the proposed image encryption scheme has good statistical output characteristics and security performance in line with cryptography.

录用期刊：COMPLEXITY