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Journal of Semiconductors 2013年第4期34卷 24-29页

作者： Godwin Raj Hemant Pardeshi Sudhansu Kumar Pati N Mohankumar Chandan Kumar Sarkar Nano Device Simulation Laboratory Electronics and Telecommunication Engineering DepartmentJadavpur UniversityKolkata-700 032India SKP Engineering College TiruvannamalaiTamilnadu-606 611India

We present a two-dimensional electron gas （2DEG） charge-control mobility variation based drain cur- rent model for sheet carrier density in the channel. The model was developed for the AIInGaN/A1N/GaN high- electron-mobility transistor. The sheet carrier density model used here accounts for the independence between the Fermi levels Ef and ns along with mobility for various AI and In molefractions. This physics based ns model fully depends upon the variation of El, u0, the first subband E0, the second subband El, and as. We present a physics based analytical drain current model using ns with the minimum set of parameters. The analytical resuks obtained are compared with the experimental results for four samples with various molefraction and barrier thickness. A good agreement between the results is obtained, thus validating the model.

关键词： 2DEG Fermi level AlInGaN

Backstepping sliding mode tracking control of quad-rotor under input saturation

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International Journal of Intelligent Computing and Cybernetics 2012年第4期5卷 515-532页

作者： Xun Gong Yue Bai Zhicheng Hou Changjun Zhao Yantao Tian Qiang Sun School of telecommunication Engineering Jilin UniversityChangchunChina Chang Chun Institute of Optics Fine Mechanics and Physics Chinese Academy of SciencesChangchunChina

Purpose–The quad-rotor is an under-actuation,strong coupled nonlinear system with parameters uncertainty,unmodeled disturbance and drive capability *** purpose of the paper is to design a flight control system to regulate the aircraft track the desired trajectory and keep the attitude angles stable on account of these ***/methodology/approach–Considering the dynamics of a quad-rotor,the closed-loop flight control system is divided into two nested loops:the translational outer-loop and the attitude *** the outer-loop,the translational controller,which exports the desired attitude angles to the inner-loop,is designed based on bounded control *** consideration of the influence of uncertain rotational inertia and external disturbance,the backstepping sliding mode approach with adaptive gains is used in the *** switching control strategy based on the sign functions of sliding surface is introduced into the design procedure with respect to the input ***–The validity of the proposed flight control system was verified through numerical simulation and prototype flight experiment in this ***,with relation to the flying,the motor speed is kept in the predetermined ***/value–This article introduces a new flight control system designed for a quad-rotor.

关键词： Quad-rotor Double-loops Backstepping algorithm Adaptive approximation Bounded control Prototype experiment Genetic algorithms Flight control

Region-based Multi-focus Image Fusion Using the Local Spatial Frequency

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Region-based Multi-focus Image Fusion Using the Local Spatia...

Decoupling Trajectory Tracking for Gliding Reentry Vehicles

第25届中国控制与决策会议

作者： Qingping Li Junping Du Fuzhao Song Chao Wang Honggang Liu Cheng Lu Beijing Key Lab of Intelligent telecommunication Software and Multimedia School of Computer Science Beijing University of Posts and Telecommunications

ISBN: (纸本)9781467355339

In image fusion domain, generic pixel-based image fusion methods are sensitive to imperfections of source images, and it therefore has much influence on the quality of the fusion results. Focusing on this problem, a region-based multi-focus image fusion scheme is proposed based on the local spatial frequency （LSF） in this paper. Firstly, calculate LSF for each pixel of source images, and a segmentation of the average image is introduced to segment the source images. From the segmented image, a shared region representation is obtained to label the source images. The identification of important features in shared region representation, region spatial frequency （RSF）, is used to guide the fusion process. The experimental results show that the proposed scheme works well in multi-focus image fusion, and it outperforms comparison methods in terms of visual and objective evaluations.

关键词： Multi-focus Image Fusion Local Spatial Frequency Image Segmentation

来源： cnki会议评论

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IEEE/CAA Journal of Automatica Sinica 2015年第1期2卷 115-120页

作者： Zixuan Liang Zhang Ren Xingyue Shao the Science and Technology on Aircraft control Laboratory Beihang University

A decoupling trajectory tracking method for gliding reentry vehicles is presented to improve the reliability of the guidance system. Function relations between state variables and control variables are analyzed. To reduce the coupling between control channels, the multiple-input multiple-output (MIMO) tracking system is separated into a series of two single-input single-output (SISO) subsystems. Tracking laws for both velocity and altitude are designed based on the sliding mode control (SMC). The decoupling approach is verified by the Monte Carlo simulations, and compared with the linear quadratic regulator (LQR) approach in some specific conditions. Simulation results indicate that the decoupling approach owns a fast convergence speed and a strong anti-interference ability in the trajectory tracking. © 2014 Chinese Association of Automation.

关键词： Airships Altitude control Channel estimation Hypersonic vehicles Intelligent systems MIMO systems Monte Carlo methods Sliding mode control telecommunication repeaters Trajectories Vehicles

Liveness detection of occluded face based on dual-modality convolutional neural network

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The Journal of China Universities of Posts and telecommunications 2021年第4期28卷 1-12页

作者： Ming Yue Li Wenmin Xu Siya Gao Lifang Zhang Hua Shao Sujie Yang Huifeng State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China State Grid Hebei Information and telecommunication Branch Shijiazhuang 050013China

Facial recognition has become the most common identity authentication technologies. However, problems such as uneven light and occluded faces have increased the hardness of liveness detection. Nevertheless, there are a few pieces of research on face liveness detection under occlusion conditions. This paper designs a face recognition technique suitable for different degrees of facial occlusion, which employs the facial datasets of near-infrared(NIR) images and visible(VIS) light images to examine the single-modality detection accuracy rate(experimental control group) and the corresponding high-dimensional features through the residual network(ResNet). Based on the idea of data fusion, we propose two feature fusion methods. The two methods extract and fuse the data of one and two convolutional layers from two single-modality detectors respectively. The fusion of high-dimensional features apply a new ResNet to get the dual-modality detection accuracy. And then, a new ResNet is applied to test the accuracy of dual-modality detection. The experimental results show that the dual-modality face liveness detection model improves face live detection accuracy and robustness compared with the single-modality. The fusion of two-layer features from the single-modality detector can also improve face detection accuracy by utilizing the above-mentioned dual-modality detector, and it doesn’t increase the algorithm’s complexity.

关键词： face deception face occlusion near-infrared image residual network feature fusion

Robust H_∞ guaranteed cost satisfactory fault-tolerant control for discrete-time systems with quadratic D stabilizability

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Journal of Systems Engineering and Electronics 2010年第3期21卷 496-502页

作者： Xiaodong Han Jiangong Liu Dexiao Xie Dengfeng Zhang Zhiquan Wang Institute of telecommunication Satellite China Academy of Space Technology Beijing 100094 P. R. China School of Automation Nanjing University of Science and Technology Nanjing 210094 E R. China

The problem of robust H∞ guaranteed cost satisfactory fault-tolerant control with quadratic D stabilizability against actuator failures is investigated for a class of discrete-time systems with value-bounded uncertainties existing in both the state and control input *** on a more practical and general model of actuator continuous gain failures,taking the transient property,robust behaviour on H∞ performance and quadratic cost performance requirements into consideration,sufficient conditions for the existence of satisfactory fault-tolerant controller are given and the effective design steps with constraints of multiple performance indices are ***,the consistency of the regional pole index,H∞ norm-bound constraint and cost performance indices is set up for fault-tolerant control.A simulation example shows the effectiveness of the proposed method.

关键词： fault-tolerant control actuator failures consistency theory quadratic D stabilizability.

Survivability model of LEO satellite constellation based on GERT with limited backup resources

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Journal of Systems Engineering and Electronics 2024年第4期35卷 976-986页

作者： NIE Yuanyuan FANG Zhigeng LIU Sifeng GAO Su College of Economics and Management Nanjing University of Aeronautics and AstronauticsNanjing 211106China Institute of telecommunication Satellite China Academy of Space TechnologyBeijing 100094China

Survivability is used to evaluate the ability of the satellite to complete the mission after failure,while the duration of maintaining performance is often *** effective backup strategy can restore the constellation performance timely,and maintain good network communication performance in case of satellite *** the perspective of network utility,the low Earth orbit(LEO)satellite constellation survivable graphical eva-luation and review technology(GERT)network with backup satel-lites is constructed.A network utility transfer function algorithm based on moment generating function and Mason formula is proposed,the network survivability evaluation models of on-orbit backup strategy and ground backup strategy are *** survivable GERT model can deduce the expected mainte-nance time of LEO satellite constellation under different fault states and the network utility generated during the state mainte-nance *** case analysis shows that the proposed surviv-able GERT model can consider the satellite failure rate,backup satellite replacement rate,maneuver control replacement ability and life requirement,and effectively determine the optimal sur-vivable backup strategy for LEO satellite constellation with limi-ted resources according to the expected network utility.

关键词： survivability low Earth orbit(LEO)satellite constella-tion graphical evaluation and review technology(GERT) backup strategy

Automatic estimation and removal of noise on digital image

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Journal of Measurement Science and Instrumentation 2013年第3期4卷 256-262页

作者： Tuananh Nguyen Beomsu Kim Mincheol Hong School of Information and telecommunication Soongsil University

An spatially adaptive noise detection and removal algorithm is *** the assumption that an observed image and its additive noise have Gaussian distribution,the noise parameters are estimated with local statistics from an observed degraded image,and the parameters are used to define the constraints on the noise detection *** addition,an adaptive low-pass filter having a variable filter window defined by the constraints on noise detection is used to control the degree of smoothness of the reconstructed *** results demonstrate the capability of the proposed algorithm.

关键词： noise estimation denoising noise parameters local statistics adaptive filterCLC number:TN911.73 Document code:AArticle ID:1674-8042(2013)03-0256-07

High-efficiency and large light-receiving area superconducting nanowire single-photon detector integrated with high-contrast grating

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Photonics Research 2021年第11期9卷 2253-2260页

作者： CHEN WEI WENCONG WANG DONGMEI LIU MIN GU XIANQIU WU School of Physics and telecommunication Engineering South China Normal UniversityGuangzhou 510006China

By using a high-contrast grating(HCG,high transmittance>90%)to control the phase shift of incident light,we theoretically designed a novel-structured HCG-integrated superconducting nanowire single-photon detector(HCG-SNSPD)with a high-efficiency and large light-receiving *** enlarging the typical single-pixel SNSPD nanowire area(10μm×10μm),the effective detection area is expanded to 115μm,while the absorption efficiency of the nanowire reaches 84.9% at a wavelength of 1550 *** effective detection area of HCGSNSPD is increased by 11.5 times compared to that of conventional single-pixel ***,the absorption efficiencies of HCG-SNSPD exceed 70% at wavelengths ranging from 1460 nm to 1650 nm,indicating high-efficiency broadband *** study promotes new possibilities for the application of SNSPDs.

关键词： SNSPD high light

Sparse Target Localization in RF Sensor Networks using Compressed Sensing

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Sparse Target Localization in RF Sensor Networks using Compr...