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A Novel Consecutive Artificial Noise Secrecy Enhancing Scheme for RIS Aided MIMO System With Imperfect CSI

IEEE Transactions on Vehicular technology 2025年

作者： Shang, Pingping Tao, Zhuofan Xie, Zhonghui Huang, Min Sui, He Li, Jun Hai, Han Hubei University of Technology School of Electrical and Electronic Engineering Wuhan430068 China Hubei University of Technology Hubei Key Laboratory for High-efficiency Utilization of Solar Energy and Operation Control of Energy Storage System Wuhan430068 China Civil Aviation University of China College of Aeronautical Engineering Tianjin300399 China Guangzhou University School of Electronics and Communication Engineering Guangzhou510006 China Donghua University College of Information Science and Technology Shanghai201620 China

Reconfigurable intelligent surface (RIS) is a technology with great promise, which is widely used in wireless networks to improve the coverage and enhance the performance. However, security concerns pose a major challenge for wireless networks, especially given inevitable errors in channel estimation. This paper proposes a high spectrum efficiency security scheme using generalized spatial modulation (GSM) and space-time block coding (STBC) for scenarios with imperfect channel state information (CSI). In this scheme, GSM uses RIS block indices as unique identifiers, ideal for secure scenarios. It operates by activating different RIS blocks over two time slots to reflect unmodulated carrier signals, while STBC is designed based on the phase shifts of the RIS. To ensure secure communication, a low-complexity continuous artificial noise (CAN) is transmitted with STBC signals to interfere with eavesdroppers and prevent them from decoding the signals. The ergodic secrecy rate is deduced, and the bit error rate (BER) is validated through experiments. The simulation results indicate that the proposed solution can remarkably improves the security performance of the RIS-assisted wireless communication systems. © 1967-2012 IEEE.

关键词： Space-time block coding (STBC)

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Fault-tolerant Model Predictive control for Hypersonic Vehicle Based on Sum of Squares

Fault-tolerant Model Predictive Control for Hypersonic Vehic...

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第40届中国控制会议

作者： Xiaohe Yang Weijie Lv Chaofang Hu Yongtai Hu School of Electrical and Information Engineering Tianjin University Aviation Key Laboratory of Science and Technology on Aircraft Control Facri

In this paper, a robust model predictive controller based on sum of squares（SOS-RMPC） is proposed to realize the trajectory tracking control of hypersonic vehicle with actuator fault. Firstly, the polytopic feedback linearization error model of hypersonic vehicle with actuator fault is derived. The integration of altitude and velocity are introduced to eliminate the steady state error. The lose efficiency fault of actuator is separated from control input and the additional bounded disturbance term is formed. Secondly, the real input constraint is converted to virtual state-dependent input constraint in polynomial. Finally,a composite control law with and without virtual state-dependent constraint is proposed, and the SOS-RMPC fault-tolerant controller is designed. By SOS technology, the virtual state-dependent input constraint in polynomial is transformed into convex optimization problem of linear matrix inequality（LMI）. The norm-bounded theory is applied to suppress the disturbance. The simulations show that the designed controller can realize trajectory tracking control of hypersonic vehicle with actuator fault.

关键词： Hypersonic vehicle Fault-tolerant control Feedback linearization Robust model predictive control Sum of Squares

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Neural Rendering and Flow-assisted Unsupervised Multi-view Stereo for Real-time Monocular Tracking and Scene Perception

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IEEE Transactions on Automation science and Engineering 2025年

作者： Tong, Kevin W. Cai, Yandong Jie, Yu-Wen Duan, Ya Hou, Yuhong Wu, Edmond Q. Nanjing University of Posts and Telecommunications College of Automation College of Artificial Intelligence Nanjing210023 China Ministry of Education Key Laboratory of Social Computing and Cognitive Intelligence Dalian University of Technology Dalian116024 China Shanxi University School of Automation and Software Engineering Shanxi 237016 China Flight Test Technology and Engineering Center of the Chinese Flight Test Establishment Xian710089 China China Civil Aviation Shanghai Aircraft Airworthiness Certification Center Shanghai200335 China Shanghai Jiao Tong University Department of Computer Science and Engineering Shanghai200240 China

The existing camera tracking and perception methods mainly rely on sparse SLAM, which limits the dense perception ability of the scene and affects the reliability of auxiliary decision-making. Different from this, this work proposes a real-time tracking and unsupervised dense sensing framework. Firstly, the dense depth value of the scene is predicted by unsupervised multi-view stereo to remove the dependence on labeled data. Then, the quality of synthetic pseudo-reference image is quantified according to the predicted depth map and used as a weighted guidance to train the unsupervised model, thus reducing the ambiguity of feature matching in areas such as specular reflection. Moreover, the sparse optical flow of the keyframes is solved by real-time and robust ORB feature matching operator, which assists the high-precision training of unsupervised depth inference model. To increase the prediction accuracy of occluded area, a novel rendering consistency loss via neural radiance fields is designed to constrain the geometric characteristics of object surface. Finally, dense direct image alignment is performed from a global model to improve the tracking robustness, which is incrementally constructed from dense depth prediction. Extensive experiments on synthetic datasets and real datasets validate the effectiveness and practicability of the proposed work, which is an effective supplement to the existing SLAM work. © 2025 IEEE.

关键词： Stereo image processing

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Sensitivity Analysis and Optimization of Geometric Parameters of a New Fluid Bag Buffer Mechanism on Buffering Performance

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Transactions of Nanjing University of Aeronautics and Astronautics 2022年第5期39卷 569-583页

作者： WANG Hongxian HOU Yu ZHANG Ming NIE Hong Key Laboratory of Advanced Technology of Small and Medium-Sized UAV Ministry of Industry and Information Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China School of Aeronautic Engineering Nanjing Vocational University of Industry TechnologyNanjing 210023P.R.China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

A new fluid bag buffer mechanism,which can provide large axial stiffness under the small displacement,is *** dynamic change laws of the mechanism stiffness and the internal pressure of the fluid bag are studied when it is subjected to impact *** to the protection performance for the flexible joint and the pressure change in the fluid bag during the impact process,the sensitivity of the geometric parameters of the fluid bag to the axial stiffness is analyzed by using the orthogonal experimental method,and the optimal parameter combination of the geometric parameters of the fluid bag under impact is obtained,leading to the displacement of the inner shell reduce by 41.4%.The results show that the internal pressure of the fluid bag is a rising process of oscillation and *** sensitivity of the geometric parameters of the fluid bag to the displacement of the inner shell from high to low is as follows:Height H,radius r,wall thickness t,chamfer *** correlation between the geometric parameters of the fluid bag and its internal pressure is:H is negatively correlated with the internal pressure,while the r,t,and A are positively correlated with the internal pressure.

关键词： fluid bag buffer mechanism flexible joint axial stiffness characteristics orthogonal experiment method internal pressure of fluid bag

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Development and global validation of a 1-week-old piglet head finite element model for impact simulations

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Chinese Journal of Traumatology 2023年第3期26卷 147-154页

作者： Zhong-Qing Su Da-Peng Li Rui Li Guang-Liang Wang Lang Liu Ya-Feng Wang Ya-Zhou Guo Zhi-Gang Li School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBejing100044China D epartment of NeurosurgeryBejing Children's Hospital CapitalMedical University.National CenterforChildren'sHealthBeijing 100045China Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics China Aircraft Strength Research InstituteXi'an70065China

Purpose:Child head injury under impact scenarios(***,vehicle crashes,etc.)is an important topic in the field of injury *** head of piglet was commonly used as the surrogate to investigate the biomechanical response and mechanisms of pediatric head injuries because of the similar cellular structures and material ***,up to date,piglet head models with accurate geometry and material properties,which have been validated by impact experiments,are *** aim to develop such a model for future ***:In this study,first,the detailed anatomical structures of the piglet head,including the skull,suture,brain,pia mater,dura mater,cerebrospinal fluid,scalp and soft tissue,were constructed based on CT ***,a structured butterfly method was adopted to mesh the complex geometries of the piglet head to generate high-quality elements and each component was assigned corresponding constitutive material ***,the guided drop tower tests were conducted and the force-time histories were ectracted to validate the piglet head finite element ***:Simulations were conducted on the developed finite element model under impact conditions and the simulation results were compared with the experimental data from the guided drop tower tests and the published *** average peak force and duration of the guide drop tower test were similar to that of the simulation,with an error below 10%.The inaccuracy was below 20%.The average peak force and duration reported in the literature were comparable to those of the simulation,with the exception of the duration for an impact energy of 11 *** results showed that the model was capable to capture the response of the pig ***:This study can provide an effective tool for investigating child head injury mechanisms and protection strategies under impact loading conditions.

关键词： Piglet head Finite element model Dynamic response Validation Drop tower tests

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Flexible Antenna Arrays for Wireless Communications: Modeling and Performance Evaluation

arXiv

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arXiv 2024年

作者： Yang, Songjie An, Jiancheng Xiu, Yue Lyu, Wanting Ning, Boyu Zhang, Zhongpei Debbah, Mérouane Yuen, Chau The National Key Laboratory of Wireless Communications University of Electronic Science and Technology of China Chengdu611731 China College of Air Traffic Management Civil Aviation Flight University of China Sichuan 618311 China KU 6G Research Center Khalifa University of Science and Technology P O Box 127788 Abu Dhabi United Arab Emirates The School of Electrical and Electronics Engineering Nanyang Technological University 639798 Singapore

Flexible antenna arrays (FAAs), distinguished by their rotatable, bendable, and foldable properties, are extensively employed in flexible radio systems to achieve customized radiation patterns. This paper aims to illustrate that FAAs, capable of dynamically adjusting surface shapes, can enhance communication performances with both omni-directional and directional antenna patterns, in terms of multi-path channel power and channel angle Cramér-Rao bounds. To this end, we develop a mathematical model that elucidates the impacts of the variations in antenna positions and orientations as the array transitions from a flat to a rotated, bent, and folded state, all contingent on the flexible degree-of-freedom. Moreover, since the array shape adjustment operates across the entire beamspace, especially with directional patterns, we discuss the sum-rate in the multi-sector base station that covers the 360◦ communication area. Particularly, to thoroughly explore the multi-sector sum-rate, we propose separate flexible precoding (SFP), joint flexible precoding (JFP), and semi-joint flexible precoding (SJFP), respectively. In our numerical analysis comparing the optimized FAA to the fixed uniform planar array, we find that the bendable FAA achieves a remarkable 156% sum-rate improvement compared to the fixed planar array in the case of JFP with the directional pattern. Furthermore, the rotatable FAA exhibits notably superior performance in SFP and SJFP cases with omni-directional patterns, with respective 35% and 281%. Copyright © 2024, The Authors. All rights reserved.

关键词： Base stations

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Hamiltonian Dynamics and Targeted Energy Transfer of a Grounded Bistable Nonlinear Energy Sink

SSRN

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SSRN 2022年

作者： Li, Shuangbao Zhou, Xinxing Chen, Jianen Research Institute of Science and Technology Civil Aviation University of China Tianjin300300 China College of Science Civil Aviation University of China Tianjin300300 China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China

A two-degree-of-freedom nonlinear mechanical system describing a damped linear oscillator weakly coupled to a lightweight grounded bistable nonlinear energy sink is proposed to investigate the targeted energy transfer (TET) under asymmetric local nonlinear potentials. The Bogdanov-Takens bifurcations of equilibria are discussed to reflect the bistable and asymmetric characteristics of the system. Through projections of isoenergetic manifolds, the topological features of the Hamiltonian dynamics under $1:1$ internal resonance have been investigated, which induces conditions for energy localization and exchange. In the general case, the topological features of the Hamiltonian dynamics related to the nonlinear normal modes (NNMs) are classified by the Poincare map, the relations between the NNMs and the Hamiltonian dynamics have been interpreted through the frequency energy plots. The results show that introducing the asymmetric characteristics may enhance the TET and realize the complete TET. © 2022, The Authors. All rights reserved.

关键词： Degrees of freedom (mechanics)

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A Generalized Non-local Quasicontinuum Approach for Efficient Modeling of Architected Truss-based Lattice Structures

arXiv

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arXiv 2025年

作者： Li, Zi Yang, Fan Yang, Qingcheng Shanghai Key Laboratory of Mechanics in Energy Engineering School of Mechanics and Engineering Science Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China School of Aerospace Engineering and Applied Mechanics Tongji University Shanghai China Key Laboratory of AI-Aided Airworthiness of Civil Aircraft Structures Civil Aviation Administration of China Tongji University Shanghai China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Dalian University of Technology Dalian China Shanghai Institute of Aircraft Mechanics and Control Shanghai China

To mitigate the substantial computational costs associated with modeling the mechanical behavior of large-scale architected lattice structures, this work introduces a concurrent multiscale approach: the Generalized Non-local Quasicontinuum (GNQC) method. GNQC generalizes the classical nonlocal Quasicontinuum framework by eliminating the assumption of affine or high-order deformation patterns for accurate energy sampling in coarse-grained regions and by ensuring consistency with general finite element shape functions used for coarse-graining. The introduced GNQC method offers three key features: (1) a constitutive-model-consistent framework that employs the same lattice constitutive relationship in both the locally full-resolution region and the coarse-grained domain, similar to existing nonlocal QC approaches;(2) a shape-function consistent energy sampling mechanism that aligns with the interpolation order of the generally employed shape functions, differing significantly from existing Quasicontinuum works and substantially reducing computational costs;and (3) consistent interfacial compatibility, which enables seamless energy and force transfer across interfaces between regions of different resolutions without cumbersome interfacial treatments. The performance of GNQC is validated through a series of numerical test cases—including tension, clamped bending, three-point bending, and crack propagation problems—that demonstrate good accuracy. Additionally, the error analysis and convergence behavior of GNQC are investigated. Copyright © 2025, The Authors. All rights reserved.

关键词： Constitutive models

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Research on Cart Decision Tree Fire Image Recognition Algorithm Considering Optimal Combination of Color Features

SSRN

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SSRN 2022年

作者： Li, Hai Sun, Peng Xiong, Sheng-Hua Civil Aircraft Fire Science and Safety Engineering Key Laboratory of Sichuan Province Civil Aviation Flight University of China Guanghan Sichuan 618307 China College of Civil Aviation Safety Engineering Civil Aviation Flight University of China Guanghan Sichuan 618307 China School of Information Science and Engineering Shenyang University of Technology Shenyang110870 China Department of Criminal Science and Technique Criminal Investigation Police University of China Shenyang110854 China

Aiming at the problem of multi-dimensional feature fusion and color feature combination optimization in the process of fire image recognition, a fire image recognition method based on CART decision tree considering the optimal combination of color features was proposed. First, in Lab, RGB and HSV color modes, eigenvalues of fire images are extracted based on image color features. Secondly, the optimal combination of color features is extracted based on fine decision tree. Finally, the extracted optimal feature combination eigenvalues of fire images are used as input of CART decision tree to classify the sample data. Experimental results show that this method has high accuracy in fire image recognition. Its classification effect is obviously better than other decision tree and ensemble tree methods. © 2022, The Authors. All rights reserved.

关键词： Decision trees

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Research on Cart Decision Tree Fire Image Recognition Algorithm Considering Optimal Combination of Color Features

SSRN

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SSRN 2022年

关键词： Decision trees

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