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An efficient and globally optimal solution to perspective-n-line problem

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Chinese Journal of Aeronautics 2022年第3期35卷 400-407页

作者： Qida YU Guili XU zhengsheng wang Zhenhua LI College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China

This research develops an accurate and efficient method for the Perspective-n-Line(Pn L)problem. The developed method addresses and solves Pn L via exploiting the problem’s geometry in a non-linear least squares fashion. Specifically, by representing the rotation matrix with a novel quaternion parameterization, the Pn L problem is first decomposed into four independent subproblems. Then, each subproblem is reformulated as an unconstrained minimization problem, in which the Kronecker product is adopted to write the cost function in a more compact form. Finally, the Groobner basis technique is used to solve the polynomial system derived from the first-order optimality conditions of the cost function. Moreover, a novel strategy is presented to improve the efficiency of the algorithm. It is improved by exploiting structure information embedded in the rotation parameterization to accelerate the computing of coefficient matrix of a cost function. Experiments on synthetic data and real images show that the developed method is comparable to or better than state-of-the-art methods in accuracy, but with reduced computational requirements.

关键词： Camera pose estimation Grobner basis Machine vision Perspective-n-Line(PnL)problem Quaternion parameterization

Arnoldi Projection Fractional Tikhonov for Large Scale Ill-Posed Problems

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第3期35卷 395-402页

作者： wang zhengsheng Mu Liming Liu Rongrong Xu Guili College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016P.N.China 2.Institute of AutomationNanjing University of Aeronautics and AstronauticsNanjing 210016P.N.China

It is well known that Tikhonov regularization in standard form may determine approximate solutions that are too smooth for ill-posed problems,so fractional Tikhonov methods have been introduced to remedy this *** Tikhonov regularization for large-scale linear ill-posed problems is commonly implemented by determining apartial Arnoldi decomposition of the given *** this paper,we propose a new method to compute an approximate solution of large scale linear discrete ill-posed problems which applies projection fractional Tikhonov regularization in Krylov subspace via Arnoldi *** projection fractional Tikhonov regularization combines the fractional matrices and orthogonal projection operators.A suitable value of the regularization parameter is determined by the discrepancy *** examples with application to image restoration are carried out to examine that the performance of the method.

关键词： ill-posed problems fractional matrix Tikhonov regularization orthogonal projection operator image restoration

A novel method for extracting and optimizing the complex permittivity of paper-based composites based on an artificial neural network model

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Science China Technological Sciences 2024年第10期67卷 3190-3204页

作者： XIA ChenBin SHEN JunYi LIAO ShaoWei wang Yi HUANG zhengsheng XUE Quan TANG Min LONG Jin HU Jian School of Light Industry and Engineering South China University of Technology School of Electronic and Information Engineering South China University of Technology

Measuring the complex permittivity of ultrathin, flexible materials with a high loss tangent poses a substantial challenge with precision using conventional methods, and verifying the accuracy of test results remains difficult. In this study, we introduce a methodology based on a back-propagation artificial neural network(ANN) to extract the complex permittivity of paper-based composites(PBCs). PBCs are ultrathin and flexible materials exhibiting considerable complex permittivity and dielectric loss tangent. Given the absence of mature measurement methods for PBCs and a lack of sufficient data for ANN training, a mapping relationship is initially established between the complex permittivity of honeycomb-structured microwave-absorbing materials(HMAMs, composed of PBCs) and that of PBCs using simulated data. Leveraging the ANN model, the complex permittivity of PBCs can be extracted from that of HMAMs obtained using standard measurement. Subsequently, two published methods are cited to illustrate the accuracy and advancement of the results obtained using the proposed approach. Additionally, specific error analysis is conducted, attributing discrepancies to the conductivity of PBCs, the homogenization of HMAMs, and differences between the simulation model and actual objects. Finally, the proposed method is applied to optimize the cell length parameters of HMAMs for enhanced absorption performance. The conclusion discusses further improvements and areas for extended research.

关键词： paper-based composite honeycomb complex permittivity artificial neural networks inverse modeling

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特征值反问题的结构探伤方法

振动．测试与诊断 2010年第4期30卷 446-450页

作者：王正盛南京航空航天大学理学院南京210016

基于特征值反问题的思想,研究了杆和梁模型结构探伤的方法,包括确定损伤的位置和损伤程度。基于几何参数,建立了有限元或有限差分离散模型,可以由系统的一个特征对重构,这种重构可以推导出振动系统结构探伤的一类特征值反问题方法,并提... 详细信息

基于特征值反问题的思想,研究了杆和梁模型结构探伤的方法,包括确定损伤的位置和损伤程度。基于几何参数,建立了有限元或有限差分离散模型,可以由系统的一个特征对重构,这种重构可以推导出振动系统结构探伤的一类特征值反问题方法,并提出了由一个特征对进行结构探伤的方法。给出了固定-固定杆、固定-自由杆和悬臂梁系统的由一个特征对进行结构探伤的方法,并给出了数值算法和算例,证明了该方法的有效性。

关键词：结构探伤特征值反问题固定-固定杆固定-自由杆悬臂梁

A Regularized Randomized Kaczmarz Algorithm for Large Discrete Ill-Posed Problems

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Transactions of Nanjing University of Aeronautics and Astronautics 2020年第5期37卷 787-795页

作者： LIU Fengming wang zhengsheng YANG Siyu XU Guili College of Science Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China

Tikhonov regularization is a powerful tool for solving linear discrete ill-posed ***,effective methods for dealing with large-scale ill-posed problems are still *** Kaczmarz method is an effective iterative projection algorithm for solving large linear equations due to its *** propose a regularized randomized extended Kaczmarz(RREK)algorithm for solving large discrete ill-posed problems via combining the Tikhonov regularization and the randomized Kaczmarz *** convergence of the algorithm is *** experiments illustrate that the proposed algorithm has higher accuracy and better image restoration quality compared with the existing randomized extended Kaczmarz(REK)method.

关键词： ill-posed problem Tikhonov regularization randomized extended Kaczmarz(REK)algorithm image restoration

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中国聋人学生英语教学研究述评

中国特殊教育 2014年第3期 17-23页

作者：王正胜天津理工大学外国语学院天津300384

特殊教育工作者们开拓了中国聋人学生英语教学的领域,并在该新领域的研究和实践上取得了一定的成果,如设置了聋人英语课程;探索了聋人英语的教学方法和聋人的英语学习特点等。在以后的教学实践与研究中,需要:加强课程体系建设的研究;重... 详细信息

特殊教育工作者们开拓了中国聋人学生英语教学的领域,并在该新领域的研究和实践上取得了一定的成果,如设置了聋人英语课程;探索了聋人英语的教学方法和聋人的英语学习特点等。在以后的教学实践与研究中,需要:加强课程体系建设的研究;重视对学习者的研究;进一步丰富教学方法;将现代信息技术与聋生英语教学相结合。

关键词：中国聋人学生英语教学法课程设置

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阻尼弹簧-质点系统中的逆二次特征值问题

高等学校计算数学学报 2005年第3期27卷 29-36页

作者：王正盛南京航空航天大学理学院南京 210016

由于二次特征值问题(QEP-QuadraticEigenvalueProblem)在结构动力学、电子振荡、陀螺仪系统、流体力学以及信号处理等领域中的广泛应用,已经或正在吸引着数学研究者和工程技术人员越来越多的关注与研究.所谓QEP就是寻求标量λ和非零向量... 详细信息

由于二次特征值问题(QEP-QuadraticEigenvalueProblem)在结构动力学、电子振荡、陀螺仪系统、流体力学以及信号处理等领域中的广泛应用,已经或正在吸引着数学研究者和工程技术人员越来越多的关注与研究.所谓QEP就是寻求标量λ和非零向量x满足:Q(λ)x=(λ2M+λC+K)x=0(1)其中M,C和K是n阶复矩阵,x是属于特征值λ的特征向量.

关键词： quadratic eigenvalue problem inverse quadratic eigenvalue problem damped mass-spring systems.

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刑罚个别化问题再研究

政治与法律 2007年第2期 110-115页

作者：王振生安阳师范学院河南安阳455002

刑罚个别化是一种与保安处分相区别,以刑罚一般化为前提,以犯罪人的人身危险性为核心的刑罚理念,其理论根基在于“报应与刑罚个别化相统一”的刑罚目的说,我国法律应在统一说的基础上对其实事求是的进行评价。

关键词：刑罚个别化保安处分人身危险陛刑罚目的

A Preconditioned Fractional Tikhonov Regularization Method for Large Discrete Ill-posed Problems

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Transactions of Nanjing University of Aeronautics and Astronautics 2022年第S1期39卷 106-112页

作者： YANG Siyu wang zhengsheng LI Wei College of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles of Ministry of Industry and Information Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China

The generalized Tikhonov regularization method is one of the most classical methods for the solution of linear systems of equations that arise from the discretization of linear ill-posed ***,the approximate solution obtained by the Tikhonov regularization method in general form may lack many details of the exact *** the fractional Tikhonov method with the preconditioned technique,and using the discrepancy principle for determining the regularization parameter,we present a preconditioned projected fractional Tikhonov regularization method for solving discrete ill-posed *** experiments illustrate that the proposed algorithm has higher accuracy compared with the existing classical regularization methods.

关键词： fractional regularization least-squares problem regularization parameter