Algorithm study of digital HPA predistortion using one novel memory type BP neural network by Chun-hui HUANG, Yong-jie WEN

“…Based on the characteristic analysis of the high power amplifier (HPA) in wide-band CMMB repeater stations,a novel neural network was proposed which can respectively process the memory effect and the nonlinear of power amplifier.The novel model based on real-valued time-delay neural networks(RVTDNN) uses the Levenberg-Marquardt (LM) optimization to iteratively update the coefficients of the neural network.Due to the new parameters w⁰in the novel NN model,the modified formulas of LM algorithm were provided.Next，in order to eliminate the over-fitting of LM algorithm,the Bayesian regularization algorithm was applied to the predistortion system.Additionally,the predistorter of CMMB repeater stations based on the indirect learning method was constructed to simulate the nonlinearity and memory effect of HPA.Simulation results show that both the NN models can improve system performance and reduce ACEPR (adjacent channel error power ratio ) by about 30 dB.Moreover,with the mean square error less than 10⁻⁶,the coefficient of network for FIR-NLNNN is about half of that for RVTDNN.Similarly,the times of multiplication and addition in the iterative process of FIR-NLNNN are about 25% of that for RVTDNN.…”
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A Structural Pounding Formulation Using Systematic Modal Truncation by Jianye Shi, Franz Bamer, Bernd Markert

“…Therefore, in this paper, a systematically controlled modal truncation strategy adapted to the seismic pounding formulation under consideration of high nonlinearity and nonsmoothness of contact problems is introduced. …”
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Distributed Power Trading System Based on Blockchain Technology by Shuguo Chen, Weibin Ding, Zhongzheng Xiang, Yuanyuan Liu

“…The power trading system has the characteristics of nonlinearity, dynamics, and complexity. Part of the business data in the trading system needs to be exposed to numerous external business systems. …”
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An EMG Keyboard for Forearm Amputees by Wenwei Yu, Ryu Kato, Fukuda Fabio, Hiroshi Yokoi, Yukinori Kakazu

“…To overcome the difficulties in analysing EMG and realising high DOF from biosignals, the following were integrated: (1) an online learning method to cope with nonlinearity and the individual difference of EMG signals; (2) a smoothing algorithm to deal with noisy recognition results and transition states; and (3) a modified Huffman coding algorithm to generate the optimal code, taking expected error and input efficiency into consideration. …”
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Model Modification of the Mill Transmission System Based on the PSO-BP Neural Network by Tao Zheng, Bao Xianle, Guo Qintao, Zhou Tianyang

“…Aiming at the complexity of the mill transmission system structure, the uncertainty of the constraint conditions among the components and the nonlinearity, a finite element model correction method based on the PSO-BP neural network is proposed in this study. …”
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MONOLITHIC PURE CENTER PIEZOELECTRIC ROTARY PLATFORM WITHOUT ACTUATOR REDUNDANCY by WU YuXi, YANG YiLing, WU GaoHua, DU HuiLin, WEI YanDing

“…In order to achieve high⁃precision and pure⁃center rotation motion in micro/nanomanipulation tasks,a monolithic pure⁃center rotation platform was designed using two⁃stage compliant amplification mechanisms and a single piezoelectric actuator.Compared with other platforms,the designed rotation platform exhibited the merits of no actuator redundancy,high natural frequency,large rotation angle,and compact structure.The static and dynamic models were established by combining the pseudo⁃rigid body and finite element methods.Also,the output angle,input stiffness,output stiffness,and natural frequency of the rotation platform were simulated by Ansys software.Finally,an experimental test system was built,and the performance of the platform was tested through several experiments.Also,the feedforward control was used to compensate for the piezoelectric hysteresis.The experimental results show that the rotation angle is 16.8 mrad,the natural frequency is 527.3 Hz,and the resolution is 0.3μrad.Meanwhile,the hysteresis nonlinearity is compensated effectively using feedforward control.Thus,the platform is capable the high precision center rotation operation.…”
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Dynamics Response Analysis of Subway Gear Transmission System with the Excitation of Time Variable Speed and Damping by Wu Huijie, Yang Jianwei, Wang Fumin

“…In order to research the influence of the excitation of variable speed and damping on subway gear transmission system,the subway helical gears model of the bend- torsion- axes is built,and the model considered the time- varying meshing stiffness,gear meshing error,backlash nonlinearity and torque of outside parameters during the subway working. …”
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Effect of Ground Motion Orientation on Seismic Responses of an Asymmetric Stress Ribbon Pedestrian Bridge by Yi Zhang, Wuchuan Pu, Qishuo Zhang, Kaiwen Liu, Hua Dong

“…The stress ribbon bridge uses ribbon in high tension to transfer loads and exhibits geometric nonlinearity under dynamic earthquake excitations. A typical double-span asymmetric stress ribbon pedestrian bridge was introduced as a prototype, and nonlinear time history analysis was performed to investigate the effect of ground motion orientation on the structural responses. …”
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Improved 2D Discrete Hyperchaos Mapping with Complex Behaviour and Algebraic Structure for Strong S-Boxes Generation by Musheer Ahmad, Eesa Al-Solami

“…The standard set of performance parameters such as nonlinearity, strict avalanche criterion, bits independent criterion, differential uniformity, and linear approximation probability is quantified to assess the security and robustness of proposed S-box. …”
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On Modelling and Comparative Study of LMS and RLS Algorithms for Synthesis of MSA by Ahmad Kamal Hassan, Adnan Affandi

“…We initially provide a tutorial-like exposition for the design aspects of MSA and for the analytical framework of the two algorithms while our second aim is to take advantage of high nonlinearity of MSA to compare the effectiveness of LMS and that of RLS algorithms. …”
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Application of Gap Metric to LADRC Design in Multilinear Model of SDR by Hongfu Wang, Qinghua Zeng, An Wang, Zongyu Zhang

“…However, the SDR also has strong nonlinearity, which brings a great challenge to the application of the LADRC in the gas flow regulation of the SDR. …”
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Flow Field and Pressure Loss Characteristics at Rotary Drillstring Joints by Minghu Nie, Yuchen Ye, Zheng Wang, Dandan Yuan, Xingyi Wang, Kai Wei

“…Considering the geometric nonlinearity of drillstring joints and the unsteady flow of annular fluid caused by pipe rotation, based on the turbulence model k−ε, the flow field characteristics demonstrate the annulus pressure losses at the drillstring joint are studied by numerical simulation. …”
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Fault Diagnosis of Crane Gearbox based on Variational Mode Decomposition and PSO-SVM by Wubang Yang, Bingpeng Gao, Fei Chen, Xinghe Zhang, Weidong Ma

“…The vibration signal of crane gearbox has the characteristics of low signal-to-noise ratio and nonlinearity，so it needs some professional knowledge and experience to realize fault diagnosis. …”
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Damage evolution in the AlMg6 alloy during high and very high cycle fatigue by Mikhail Bannikov, Dmitry Bilalov, Vladimir Oborin, Oleg Naimark

“…Paper presents the �in situ� method for determining of irreversible fatigue damage accumulation, based on the analysis of nonlinear manifestations of the feedback signal in a closed system of an ultrasonic fatigue system. …”
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Design formation of a transmedia project by A. М. Arakelyan, Yu. V. Vorontsova

“…The article studies such a phenomenon of the media sphere as transmedia, which is characterized by the nonlinearity and hybridity of audiovisual forms. It is a new key feature of the media sphere and makes significant changes to screen art. …”
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Chaotic Behaviour Investigation of a Front Opposed-Hemispherical Spiral-Grooved Air Bearing System by Cheng-Chi Wang

“…Studies show that some of the design problems encountered are dynamic and include critical speed, nonlinearity, gas film pressure, unbalanced rotors, and even poor design, all of which can result in the generation of chaotic aperiodic motion and instability under certain conditions. …”
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A Novel SHLNN Based Robust Control and Tracking Method for Hypersonic Vehicle under Parameter Uncertainty by Chuanfeng Li, Hao Wu, Zhile Yang, Yongji Wang, Zeyu Sun

“…Hypersonic vehicle is a typical parameter uncertain system with significant characteristics of strong coupling, nonlinearity, and external disturbance. In this paper, a combined system modeling approach is proposed to approximate the actual vehicle system. …”
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Bus Voltage Stabilization Control of Photovoltaic DC Microgrid Based on Fuzzy-PI Dual-Mode Controller by Yu Zhang, Shuhao Wei, Jin Wang, Lieping Zhang

“…The photovoltaic DC microgrid has strong nonlinearity and time variation. Therefore, traditional dual closed-loop control strategy of voltage and current based on PI controller cannot effectively restrain the fluctuation and impact of DC bus voltage when the dynamic response of the system is improved. …”
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Hysteresis Modeling of Magnetic Shape Memory Alloy Actuator Based on Krasnosel'skii-Pokrovskii Model by Miaolei Zhou, Shoubin Wang, Wei Gao

“…Compared with traditional actuators, MSMA actuator has the advantages as fast response and large deformation; however, the hysteresis nonlinearity of the MSMA actuator restricts its further improving of control precision. …”
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Comprehensive Interpretation of a Three-Point Gauss Quadrature with Variable Sampling Points and Its Application to Integration for Discrete Data by Young-Doo Kwon, Soon-Bum Kwon, Bo-Kyung Shim, Hyun-Wook Kwon

“…By applying the quadratically extrapolated integrals and nonlinearity index, the accuracy of the integration could be increased significantly for evenly acquired data, which is popular with modern sophisticated digital data acquisition systems, without using higher-order extrapolation polynomials.…”
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