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Defence Technology（防务技术） 2024年第4期34卷 328-338页

作者： yangtian Liu xiaopeng yan Qiang Liu Tai An Jian Dai Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference ***,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio *** solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is ***,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)***,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for *** DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical *** trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.

关键词： Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze

Underdetermined direction of arrival estimation with nonuniform linear motion sampling based on a small unmanned aerial vehicle platform

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Defence Technology（防务技术） 2024年第3期33卷 352-363页

作者： Xinwei Wang xiaopeng yan Tai An Qile Chen Dingkun Huang Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DOA)estimation performance suffers from significant performance degradation owing to the limited number of physical *** improve the underdetermined DOA estimation performance of a ULA radar mounted on a small UAV platform,we propose a nonuniform linear motion sampling underdetermined DOA estimation *** the motion of the UAV platform,the echo signal is sampled at different ***,according to the concept of difference co-array,a virtual ULA with multiple array elements and a large aperture is synthesized to increase the degrees of freedom(DOFs).Through position analysis of the original and motion arrays,we propose a nonuniform linear motion sampling method based on ULA for determining the optimal *** the condition of no increase in the aperture of the physical array,the proposed method obtains a high DOF with fewer sampling runs and greatly improves the underdetermined DOA estimation performance of *** results of numerical simulations conducted herein verify the superior performance of the proposed method.

关键词： Unmanned aerial vehicle(UAV) Uniform linear array(ULA) Direction of arrival(DOA) Difference co-array Nonuniform linear motion sampling method

Cognitive interference decision method for air defense missile fuze based on reinforcement learning

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Defence Technology（防务技术） 2024年第2期32卷 393-404页

作者： Dingkun Huang xiaopeng yan Jian Dai Xinwei Wang yangtian Liu Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

To solve the problem of the low interference success rate of air defense missile radio fuzes due to the unified interference form of the traditional fuze interference system,an interference decision method based Q-learning algorithm is ***,dividing the distance between the missile and the target into multiple states to increase the quantity of state ***,a multidimensional motion space is utilized,and the search range of which changes with the distance of the projectile,to select parameters and minimize the amount of ineffective interference *** interference effect is determined by detecting whether the fuze signal ***,a weighted reward function is used to determine the reward value based on the range state,output power,and parameter quantity information of the interference *** effectiveness of the proposed method in selecting the range of motion space parameters and designing the discrimination degree of the reward function has been verified through offline experiments involving full-range missile *** optimal interference form for each distance state has been *** with the single-interference decision method,the proposed decision method can effectively improve the success rate of interference.

关键词： Cognitive radio Interference decision Radio fuze Reinforcement learning Interference strategy optimization

Restrictive versus liberal fluid therapy for major abdominal surgery: is the evidence strong?

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Hepatobiliary Surgery and Nutrition 2018年第3期7卷 225-226页

作者： Yudong Qiu xiaopeng yan Department of Hepatobiliary and Pancreas Surgery Drum Tower HospitalMedical School of Nanjing UniversityNanjing 210008China

We have read with great interest the original study by Myles et al. (1), in which the authors claimed a restrictive fluid regimen during and up to 24 hours after major abdominal surgery was associated with higher rate of acute kidney injury. This international, randomized, assessor-blinded trail compared the following outcomes between restrictive and liberal intravenous-fluid regimen: disability-free survival at 1 year, acute kidney injury at 30 days, renal-replacement therapy at 90 days, septic complications, surgical-site infection, and death. The perioperative fluid management is of great clinical significance, the results demonstrated by Myles et al. provide high-level evidence with dedicate design and adequate case volume, serving as potential reference to guidelines of surgical patient care. Shortly after its online publication, the article has drawn tremendous attention and caused extensive discussion among surgeons world-wide.

关键词： fluid acute trail

Synchronously scrambled diffuse image encryption method based on a new cosine chaotic map

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Chinese Physics B 2022年第8期31卷 296-309页

作者： xiaopeng yan Xingyuan Wang Yongjin Xian School of Information Science and Technology Dalian Maritime UniversityDalian 116026China Guangxi Key Laboratory of Multi-source Information Mining&Security Guangxi Normal UniversityGuilin 541004China

We present a new cosine chaotic mapping proved by chaos theory test and analysis such that the system has good cryptography properties, wide chaos range, simple structure, and good sensitivity to initial value, and the mapping can meet the needs of chaotic image encryption. Based on the cosine chaotic system, we propose a new encryption method. First,according to the cyclic characteristics of the mapping, the cyclic information wave is simulated. Second, the quasi-Doppler effect is used to synchronously scramble and diffuse the image to obfuscate the original pixel. Finally, the XOR diffusion of image pixels is carried out by information wave to further enhance the encryption effect. Simulation experiment and security analysis show that the algorithm has good security, can resist the common attack mode, and has good efficiency.

关键词： chaos mapping cosine mapping cyclic information wave doppler effect image encryption

Automatic modulation recognition of radiation source signals based on two-dimensional data matrix and improved residual neural network

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Defence Technology（防务技术） 2024年第3期33卷 364-373页

作者： Guanghua Yi Xinhong Hao xiaopeng yan Jian Dai yangtian Liu yanwen Han Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China BIT Tangshan Research Institute Beijing 100081China

Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive ***,the AMR of radiation source signals at low SNRs still faces a great ***,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this ***,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing ***,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR ***,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation *** analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR *** recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.

关键词： Automatic modulation recognition Radiation source signals Two-dimensional data matrix Residual neural network Depthwise convolution

Blind parameter estimation of pseudo-random binary code-linear frequency modulation signal based on Duffing oscillator at low SNR

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Chinese Physics B 2021年第5期30卷 312-319页

作者： Ke Wang xiaopeng yan† Ze Li Xinhong Hao Honghai Yu Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

Conventional parameter estimation methods for pseudo-random binary code-linear frequency modulation(PRBC-LFM)signals require prior knowledge,are computationally complex,and exhibit poor performance at low signal-to-noise ratios(SNRs).To overcome these problems,a blind parameter estimation method based on a Duffing oscillator array is proposed.A new relationship formula among the state of the Duffing oscillator,the pseudo-random sequence of the PRBC-LFM signal,and the frequency difference between the PRBC-LFM signal and the periodic driving force signal of the Duffing oscillator is derived,providing the theoretical basis for blind parameter *** based on amplitude method,short-time Fourier transform method,and power spectrum entropy method are used to binarize the output of the Duffing oscillator array,and their performance is *** pseudo-random sequence is estimated using Duffing oscillator array synchronization,and the carrier frequency parameters are obtained by the relational expressions and characteristics of the difference *** results show that this blind estimation method overcomes limitations in prior knowledge and maintains good parameter estimation performance up to an SNR of-35 dB.

关键词： Duffing oscillator pseudo-random binary code-linear frequency modulation(PRBC-LFM)signal blind parameter estimation low signal-to-noise ratio(SNR)

Experimental study on the controlling factors of frictional coefficient for lost circulation control and formation damage prevention in deep fractured tight reservoir

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Petroleum 2022年第3期8卷 352-362页

作者： Chengyuan Xu Honglin Zhang Mingming Zhu Yili Kang xiaopeng yan Jingyi Zhang Yingrui Bai State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengduChina School of Petroleum Engineering China University of Petroleum(East China)QingdaoChina Changqing Drilling Branch CNPC Chuanqing Drilling Engineering Co.Ltd.Xi'an 710000China

Working fluids loss is a major contributor to low productivity during production process of fractured tight *** circulation control effect directly related to the tribological behavior between fracture surface and lost circulation materials(LCMs).In this study,the friction coefficient(FC)was investigated using typical clastic rocks and LCMs by considering multiple effect factors divided into external condition and internal *** results show that normal load had a relatively high effect on sliding model.A positive correlation was observed between FC and asperities *** decreased induced by particle size degradation of rigid *** LCMs manifested higher FC compared with rigid *** the lubrication condition by working fluid,FC of rigid LCMs was mainly controlled by their surface *** of organic LCMs is more sensitive to high temperature aging than inorganic *** plugging experiments show that LCMs optimized based on the research results can effectively improve the efficiency and strength of fracture plugging.

关键词： Fractured tight reservoirs Lost circulation control Friction coefficient Lost circulation materials

Construction of an intrahepatic portosystemic shunt using the magnetic compression technique: preliminary experiments in a canine model

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Hepatobiliary Surgery and Nutrition 2022年第4期11卷 611-615页

作者： Miaomiao Zhang Jia Ma Yingfeng An Yi Lyu xiaopeng yan Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anChina National Local Joint Engineering Research Center of Precision Surgery&Regenerative Medicine The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’anChina Department of Surgical Oncology Shaanxi Provincial People’s HospitalXi’anChina Drug Non-Clinical Evaluation Center of Guangzhou Institute of Pharmaceutical Industry Guangzhou General Pharmaceutical Research Institute Co.Ltd.GuangzhouChina

Portal hypertension caused by liver cirrhosis due to hepatitis is a common clinical condition that can cause bleeding from esophageal and gastric varices in severe *** 1969,Rösch et *** described a successful transjugular intrahepatic portosystemic shunt(TIPS)in animal experiments(1).In 1989,Richter et *** used this technology in clinical practice(2).

关键词： al. shunt clinical

A Real-time Lithological Identification Method based on SMOTE-Tomek and ICSA Optimization

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 518-530页

作者： DENG Song PAN Haoyu LI Chaowei yan xiaopeng WANG Jiangshuai SHI Lin PEI Chunyu CAI Meng College of Petroleum Engineering Changzhou UniversityChangzhouJiangsu 213000China

In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on machine learning and mud logging data is studied in this *** method can effectively utilize downhole parameters collected in real-time during drilling,to identify lithology in real-time and provide a reference for optimization of drilling *** the imbalance of lithology samples,the synthetic minority over-sampling technique(SMOTE)and Tomek link were used to balance the sample number of five ***,this paper introduces Tent map,random opposition-based learning and dynamic perceived probability to the original crow search algorithm(CSA),and establishes an improved crow search algorithm(ICSA).In this paper,ICSA is used to optimize the hyperparameter combination of random forest(RF),extremely random trees(ET),extreme gradient boosting(XGB),and light gradient boosting machine(LGBM)*** addition,this study combines the recognition advantages of the four *** accuracy of lithology identification by the weighted average probability model reaches *** study of this paper realizes high-precision real-time lithology identification method,which can provide lithology reference for the drilling process.

关键词： mud logging data real-time lithological identification improved crow search algorithm petroleum geological exploration SMOTE-Tomek