检索结果-内蒙古大学图书馆

Real-time Monocular 3D Pose Tracking for Non-cooperative Spacecraft in Close Range

IEEE Transactions on Instrumentation and Measurement 2025年

作者： Tang, Hao Liu, Chang Liu, Jia Zhang, Pandeng Hu, Weiduo Chinese Academy of Sciences Shenzhen Institutes of Advanced Technology Shenzhen China Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing Shenzhen China University of Chinese Academy of Sciences Beijing China Beihang University School of Astronautics Beijing China

Real-time pose tracking for noncooperative spacecraft is crucial for numerous space missions, such as debris removal and docking. Existing pose tracking methods either suffer from shadow occlusion and cluttered backgrounds in space or lack computational efficiency. This study proposes a real-time system for tracking the 6-degree-of-freedom pose of a noncooperative spacecraft for proximity operations using a single calibrated camera. The proposed method parameterizes the pose in the Lie group of SE(3) and exploits the 3D boundaries and 3D contour, which are automatically extracted from the 3D model of the spacecraft as geometric features (GFs). At each frame of the tracking process, the initial pose is predicted using an error state Kalman filter (ESKF). Using the initial pose, the tracking system searches the input image for the 2D edge points that are associated with the 3D GFs based on a conditional random field and then rapidly determines the spacecraft pose in SE(3) by minimizing the distances of the projected 3D GFs to their corresponding 2D edge points using the M-estimation and Newton’s method. The covariance of the optimized pose is estimated based on the Karush–Kuhn–Tucker condition for pose optimization. With the estimated pose covariance, the ESKF is developed based on second-order autoregression in SE(3) to produce the maximum a posteriori estimate of the pose and initialize the pose tracking at the next frame. A sufficient number of synthetic and real trials indicate that the proposed method outperforms the existing methods in terms of accuracy and efficiency. The experimental results reveal that the proposed method achieves a rotation angle error of approximately 0.5° and relative position error of approximately 0.6% and that the average runtime of the proposed method is approximately 0.02 seconds per frame. © 1963-2012 IEEE.

关键词： Computational geometry

来源：评论

学校读者我要写书评

暂无评论

QoS-Based Beamforming and Compression Design for Cooperative Cellular Networks via Lagrangian Duality

引用

IEEE Transactions on Signal Processing 2025年

作者： Fan, Xilai Liu, Ya-Feng Liu, Liang Chang, Tsung-Hui Chinese Academy of Sciences State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Beijing100190 China The Hong Kong Polytechnic University Department of Electronic and Information Engineering Hong Kong Hong Kong The Chinese University of HongKong School of Science and Engineering Shenzhen Shenzhen China Shenzhen Research Institute of Big Data China

This paper considers the quality-of-service (QoS)-based joint beamforming and compression design problem in the downlink cooperative cellular network, where multiple relay-like base stations (BSs), connected to the central processor via ratelimited fronthaul links, cooperatively transmit messages to the users. The problem of interest is formulated as the minimization of the total transmit power of the BSs, subject to all users' signal-to-interference-plus-noise ratio (SINR) constraints and all BSs' fronthaul rate constraints. In this paper, we first show that there is no duality gap between the considered joint optimization problem and its Lagrangian dual by showing the tightness of its semidefinite relaxation (SDR). Then, we propose an efficient algorithm based on the above duality result for solving the considered problem. The proposed algorithm judiciously exploits the special structure of an enhanced Karush-Kuhn-Tucker (KKT) conditions of the considered problem and approaches the solution that satisfies the enhanced KKT conditions via two fixed point iterations. Two key features of the proposed algorithm are: (1) it is able to detect whether the considered problem is feasible or not and find its globally optimal solution when it is feasible;(2) it is highly efficient because both of the fixed point iterations in the proposed algorithm are linearly convergent and function evaluations in the fixed point iterations are computationally cheap. Numerical results show the global optimality and efficiency of the proposed algorithm. © 1991-2012 IEEE.

关键词： Lagrange multipliers

来源：评论

学校读者我要写书评

暂无评论

Joint Design of Radar Receive Filter and Unimodular ISAC Waveform with Sidelobe Level Control

arXiv

引用

arXiv 2025年

作者： Zhang, Kecheng Liu, Ya-Feng Wang, Zhongbin Yuan, Weijie Keskin, Musa Furkan Wymeersch, Henk Xia, Shuqiang School of System Design and Intelligent Manufacturing The Shenzhen Key Laboratory of Robotics and Computer Vision Southern University of Science and Technology Shenzhen518055 China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Department of Electrical Engineering Chalmers University of Technology Gothenburg41296 Sweden ZTE Corporation The State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen518055 China

Integrated sensing and communication (ISAC) has been considered a key feature of next-generation wireless networks. This paper investigates the joint design of the radar receive filter and dual-functional transmit waveform for the multiple-input multiple-output (MIMO) ISAC system. While optimizing the mean square error (MSE) of the radar receive spatial response and maximizing the achievable rate at the communication receiver, besides the constraints of full-power radar receiving filter and unimodular transmit sequence, we control the maximum range sidelobe level, which is often overlooked in existing ISAC waveform design literature, for better radar imaging performance. To solve the formulated optimization problem with convex and nonconvex constraints, we propose an inexact augmented Lagrangian method (ALM) algorithm. For each subproblem in the proposed inexact ALM algorithm, we custom-design a block successive upper-bound minimization (BSUM) scheme with closed-form solutions for all blocks of variable to enhance the computational efficiency. Convergence analysis shows that the proposed algorithm is guaranteed to provide a stationary and feasible solution. Extensive simulations are performed to investigate the impact of different system parameters on communication and radar imaging performance. Comparison with the existing works shows the superiority of the proposed algorithm. © 2025, CC BY-NC-SA.

关键词： Mean square error

来源：评论

学校读者我要写书评

暂无评论

Improving Performance of Virtual Machine Covert Timing Channel Through Optimized Run-Length Encoding

引用

Journal of Computer Science & Technology 2023年第4期38卷 793-806页

作者：王翀陈荣亮古亮 Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China Sangfor Technologies Inc. Shenzhen 518055China Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing Shenzhen 518055China

With its wider acceptability,cloud can host a diverse set of data and applications ranging from entertainment to personal to *** foundation of cloud computing is based on virtual machines where boundaries among the application data are very thin,and the potential of data leakage exists all the *** instance,a virtual machine covert timing channel is an aggressive mechanism to leak confidential information through shared components or networks by violating isolation and security policies in *** performance of a covert timing channel(covert channel)is crucial to adversaries and attempts have been made to improve the performance of covert timing channels by advancing the encoding mechanism and covert information *** promising,the redundancy of the covert message is mainly *** paper applies three encoding schemes namely run-length,Huffman,and arithmetic encoding schemes for data compression of a virtual machine covert timing channel by exploiting ***,the paper studies the performance of such channels according to their ***,we show that these encoding schemes still contain redundancy in a covert channel scenario,and thereby a new encoding scheme namely optimized Runlength encoding(OptRLE)is presented that greatly enhances the performance of a covert timing *** optimizations schemes adopted by OptRLE are also discussed,and a mathematical model of the behavior of an OptRLE-based covert timing channel is *** theoretical capacity of a channel can be obtained using the proposed *** analysis reveals that OptRLE further improves the performance of a covert timing channel,in addition to the effects of the *** result shows how OptRLE affects the size of covert data and the capacity of covert timing channels,and why the performance of the covert timing channel is improved.

关键词： covert storage channel information security covert channel threat evaluation anti-detection criterion covert channel restriction

来源：评论

学校读者我要写书评

暂无评论

Model-based Visual 3D Pose Tracking of Non-cooperative Spacecraft in Close Range 74

Model-based Visual 3D Pose Tracking of Non-cooperative Space...

引用

74th International Astronautical Congress, IAC 2023

作者： Liu, Chang Tang, Hao Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Guangdong Shenzhen518055 China Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing Shenzhen China

This work proposes a new monocular algorithm to track the 3D pose of non-cooperative spacecraft for proximity operations in real time with the 3D boundaries and 3D contour of the spacecraft as features. The 3D boundary segments of the spacecraft are automatically extracted from the 3D spacecraft model a priori. At the beginning instant of tracking, the tracking system is initialized by a pose retrieval method. At the following time instant, with the initial pose and its covariance provided by the extended Kalman filter (EKF), the 3D contour segments are rapidly extracted from the 3D model. The boundary segments and contour segments are taken as 3D features. In the input image, we search the image data corresponding to the 3D features within the range decided by the initial pose and its covariance. Then, the spacecraft pose is determined in real time by minimizing the geometric distances of the 3D features to the back-projection lines of their corresponding image data. The covariance of the pose is estimated via the first-order optimal condition of the minimization. Eventually, the EKF is derived from the second-order autoregression (2nd-AR) to generate the final pose estimate, and the initial pose and its covariance for next time instant. The synthetic trials quantitatively indicate that our method can track the 3D pose of spacecraft in real time with high accuracy and has outstanding robustness to the dark occlusion, cluster background, large image distance, and image noise. The real trial qualitatively validates the effectiveness of our tracking method. Copyright © 2023 by the International Astronautical Federation (IAF). All rights reserved.

关键词： Kalman filter Pose determination Spacecraft Tracking

来源：评论

学校读者我要写书评

暂无评论

Parallel Numerical Simulation of Blood Flows in Patient-specific Aortic Dissection 6

Parallel Numerical Simulation of Blood Flows in Patient-spec...

引用

6th IEEE International Conference on Computer and Communication Systems, ICCCS 2021

作者： Tu, Jiali Qin, Shanlin Chen, Rongliang Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen China University of Chinese Academy of Sciences Beijing China Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing Shenzhen China

ISBN: (纸本)9780738126043

Aortic dissection is the separation of the inner layers of the aortic wall, which allows the blood to flow into it. The computational fluid dynamics allows a better understanding of its pathology and treatment. However, it is time-consuming due to the computationally expensive. In this work, we introduce a parallel algorithm for accurate and fast three-dimensional blood flow simulation of a patient-specific full-size aorta with dissections. Specifically, the unsteady Navier-Stokes equations are discretized by a unstructured finite element method in space and a fully implicit finite difference method in time, and the fully coupled nonlinear system at each time step is solved by a domain decomposition method based parallel scalable iterative algorithm. The numerical results are carefully analyzed and it shows that the simulated pressure, velocity, and wall shear stress are within a reasonable range. In addition, the algorithm achieves a parallel efficiency of 40% when using 3840 processor cores on the Tianhe-2A supercomputer, which shows the potential to do fast and high fidelity blood flow simulations of aortic dissection. © 2021 IEEE.

关键词： Iterative methods

来源：评论

学校读者我要写书评

暂无评论

Parallel Numerical Simulation of Human Left Ventricular Diastole Based on Fluid-structure Interaction 6

Parallel Numerical Simulation of Human Left Ventricular Dias...

引用

6th IEEE International Conference on Computer and Communication Systems, ICCCS 2021

作者： Chang, Yujia Jiang, Yi Chen, Rongliang Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen China University of Chinese Academy of Sciences Beijing China Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing Shenzhen China

ISBN: (纸本)9780738126043

In this paper, we propose a parallel fluid-structure interaction solution method for the simulation of the diastolic process of the human left ventricle. The three dimensional geometry of a patient-specific left ventricle is first segmented from a medical image, and then based on which an unstructured mesh is generated. The coupled fluid-structure interaction equations are spatially discretized by a finite element method on the unstructured mesh and a fully implicit scheme is introduced for the temporal discretization. At each timestep of the fully implicit method, a scalable parallel method is applied for solving the large scale nonlinear system. Numerical experiments show that the proposed method scales up to 1920 processor cores on the Tianhe-2A supercomputer for solving a problem with over 7.9 million unstructured tetrahedrons, which shows a potential to do high-fidelity simulation of human heart for clinical applications. © 2021 IEEE.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

Symplectic-energy-first integrators of discrete mechanico-electrical dynamical systems

引用

Chinese Physics B 2008年第11期17卷 3942-3952页

作者：傅景礼陈本永唐贻发付昊 Institute of Mathematical Physics Zhejiang Sci-Tech University Faculty of Mechanical-Engineering & Automation Zhejiang Sci-Tech University State Key Laboratory of Scientific and Engineering Computing Chinese Academy of Sciences China Jingye Engineering Corporation Limited Shenzhen Brach

A discrete total variation calculus with variable time steps is presented for mechanico-electrical systems where there exist non-potential and dissipative forces. By using this discrete variation calculus, the symplectic-energy-first integrators for mechanico-electrical systems are derived. To do this, the time step adaptation is employed. The discrete variational principle and the Euler-Lagrange equation are derived for the systems. By using this discrete algorithm it is shown that mechanico-electrical systems are not symplectic and their energies are not conserved unless they are Lagrange mechanico-electrical systems. A practical example is presented to illustrate these results.

关键词： total variation symplectic-energy-momentum integrator mechanico-electrical system

来源：评论

学校读者我要写书评

暂无评论

Lattice QCD determination of unpolarized TMDPDFs of the nucleon 10

Lattice QCD determination of unpolarized TMDPDFs of the nucl...

引用

10th International Conference on Quarks and Nuclear Physics, QNP 2024

作者： Zhang, Qi-An He, Jin-Chen Chu, Min-Huan Hua, Jun Ji, Xiangdong Schäfer, Andreas Su, Yushan Wang, Wei Yang, Yi-Bo Zhang, Jian-Hui School of Physics Beihang University Beijing102206 China Yang Yuanqing Scientific Computering Center Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai200240 China School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Department of Physics University of Maryland College ParkMD20742 United States Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China Institut für Theoretische Physik Universität Regensburg RegensburgD-93040 Germany Institute of Modern Physics Chinese Academy of Sciences Guangdong Province Huizhou516000 China CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study UCAS Hangzhou310024 China International Centre for Theoretical Physics Asia-Pacific Beijing China School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China School of Science and Engineering The Chinese University of HongKong Shenzhen518172 China Center of Advanced Quantum Studies Department of Physics Beijing Normal University Beijing100875 China

We present a first calculation of the unpolarized nucleon’s isovector transverse-momentum-dependent parton distribution functions (TMDPDFs) from lattice QCD, which are essential to predict observables of multi-scale, semi-inclusive processes in the standard model. We use a Nf = 2 + 1 + 1 MILC ensemble with valence clover fermions on a highly improved staggered quark (HISQ) sea to compute the quark momentum distributions in a large-momentum nucleon on the lattice. The state-of-the-art techniques in renormalization and extrapolation in the correlation distance on the lattice are adopted. The perturbative kernel up to next-to-next-to-leading order is taken into account, and the dependence on the pion mass and the hadron momentum is explored. Our results are qualitatively comparable with phenomenological TMDPDFs, which provide an opportunity to predict high energy scatterings from first principles. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).

关键词： Crystal lattices

来源：评论

学校读者我要写书评

暂无评论

Prediction of multi-parameters in the inverse heat conduction problems

Prediction of multi-parameters in the inverse heat conductio...

引用

2020 International Conference on Physics, Mechanics and Mathematical Science, PMMS 2020

作者： Abdelhamid, Talaat Chen, Rongliang Alam, Mahbub Shenzhen Institutes of Advanced Technology Chinese Academy of Science Shenzhen China Institute for Turbulence-Noise-Vibration Interaction and Control Shenzhen Graduate School Harbin Institute of Technology Shenzhen China Physics and Mathematical Engineering Department Faculty of Electronic Engineering Menoufiya University Menouf Egypt Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing Shenzhen China

This paper studies the prediction of the spatial-dependent-heat transfer coefficient γ(x) and- heat flux q(x), using the modified conjugate gradient method (MCGM). The mathematical formulation of the problem well defined and the existence of the minimizer is investigated. We establish the sensitivity and adjoint equations for computing the gradient with respect to γ(x) and q(x). The proposed algorithm 4.1 is derived for reconstructing γ(x) and q(x) using the MCGM. The numerical experiments are examined to show the efficiency and accuracy of the proposed method. Finally, some conclusions and remarks are given. © Published under licence by IOP Publishing Ltd.

关键词： Conjugate gradient method

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：