利用位置和加速度反馈的矩阵二阶系统特征结构配置

考虑一类利用位置和加速度反馈二阶线性系统的特征结构配置问题．在允许闭环系统的特征值是未知的前提下,结合矩阵多项式的右互质分解提出二阶线性系统特征结构配置的参数化方法,建立反馈增益阵和特征向量矩阵的显示参数化表达式．本文涉及的参数化方法直接将二阶系统模型转化为一阶状态空间形式,从而降低了系统设计中的计算工作量,并且提出的算法简单,无“返回”步骤．最后,数值算例表明了该算法的有效性．     

基于Hessian图正则稀疏NMF的高光谱解混

基于非负矩阵分解(Nonnegative Matrix Factorization, NMF)的高光谱解混(Hyperspectral Unmixing,HU)方法引起了大家的关注,因为可以将一个非负高光谱图像(Hyperspectral Imagery, HSI)数据矩阵分解为两个非负矩阵的乘积,分别对应于端元矩阵和丰度系数矩阵。目前,图约束的NMF算法已经被证明对高光谱解混是有效的,因为它们可以捕获HSI的几何特性。为了挖掘数据在混合过程中的几何结构和稀疏性,提出了一种稀疏的Hessian图正则化NMF(SHGNMF)算法。SHGNMF算法是将丰度矩阵的L1/2正则化器和Hessian图正则化项都添加到每个NMF模型中,同时采用乘法更新规则。最后用模拟数据和真实数据进行实验,验证了所提出的SHGNMF算法相对于其他NMF算法的优越性。     

找到不可约多项式的研究与FoxPro程序实现

在扩频通信与传统的密码体制中广泛使用的伪随机序列,大部分是利用不可约多项式通过反馈位移寄存器和其他非线性逻辑来产生的。同时,多项式理论,特别是不可约多项式的性质对分析各种伪随机序列有着特殊的作用。 (1)找到非负整系数不可约多项式的原理 建立非负整系数多项式与正整数的符号对应和运算对应:设α_0,α_1,α_2,α_3,…,α_n是非负整数,2,3,5,7,…,p_n是n+1个相邻的素数。用正整数2~(α_0)3~(α_1)5~(α_2)(?)p_n~(α_n)表示非负整系数多项式α_0+α_1x+α_2x~2+…+α_nx~n。记作:{α_0+α_1x+α_2x~2+…+α_nx~n}←→2~(α_0)3~(α_1)5~(α_2)(?)p_n~(α_n)。     

一类多项式矩阵方程的洁式解法

本文实际上建议了关于两种多项式矩阵方程X(s)P(s) Y(s)R(s)=F(s)和P(s)X(s) Q(s)Y(s)=G(s)的结式阵解法,式中X(s)和Y(s)为未知多项式阵,其余为适当维数的已知多项式阵。这种解法可以形成计算机算法的基础。它可以用于补偿器的设计。     

基于Hessian正则化的多视图联合非负矩阵分解算法

非负矩阵在表征多视图数据时没有考虑数据本身的流型结构,不能有效表达数据内部信息。为此,提出一种基于Hessian正则化的非负矩阵分解算法。利用Hessian泛函的L2模,保持样本局部拓扑结构,并扩展成基于Hessian正则化的联合非负矩阵分解算法,以对多视图数据进行变换。实验结果表明,基于Hessian正则化的非负矩阵分解算法和基于Hessian正则化的联合非负矩阵分解算法的聚类精度以及互信息值都有较大提高,2种算法的数据变化性能都优于传统非负矩阵分解算法。     

SVRRPMCC:一种支持向量回归机的正则化路径近似算法

正则化路径算法是数值求解支持向量回归机(Support Vector Regression,SVR)的有效方法。根据SVR正则化路径的分段线性性质,该类算法可在相当于一次SVR求解的时间复杂度内求得正则化参数的所有可能取值及对应SVR的解。由于在解路径建立过程中需要求解线性方程组,已有的精确计算方法难以处理大规模的样本数据,因此研究了正则化路径近似算法,并提出了SVR正则化路径近似算法SVRRPMCC。首先,应用Monte Carlo方法实现线性方程组系数矩阵的随机采样,求得近似系数矩阵; 然后,应用Cholesky分解方法实现快速求解系数逆矩阵;进一步,分析了SVRRPMCC算法的近似误差和计算复杂性;最后,在标准数据集上的实验验证了SVRRPMCC算法的合理性和较高的计算效率。     

一种自适应正则化的图像超分辨率算法

提出一种自适应正则化的图像超分辨率重建算法. 首先, 利用局部残差均值自适应地计算各低分辨率图像通道的权值参数矩阵, 可有效地利用各通道对应区域间的交叉信息; 其次, 利用正则项局部误差均值自适应地计算平衡正则项和保真项的正则化参数矩阵, 能较好地保持图像边缘纹理等信息.实验结果表明本文算法不但具有较高峰值信噪比(Peak signal to noise ratio, PSNR) 和结构相似度(Structural similarity, SSIM), 而且在边缘、纹理等细节区域具有更好的重建效果.     

电容层析成像系统图像重建算法的研究

本文利用Tikhonov正则化和奇异系统理论,分析了引起电容层析成像系统逆问题不适定性的根本原因是由于敏感场矩阵小奇异值的存在。针对一般Tikhonov正则化方法将所有的奇异值都采取同一正则化参数修正带来的误差,本文将小奇异值对应的项设定正则化参数,而舍去零奇异值对应向量,既减少了误差又加快了速度。例算结果表明,用本文方法重建图像,比其它如线性反投影算法(LBP)、Landweber迭代法及一般Tikhonov正则化算法,都有一定程度的改善。     

广义动态系统的微分算子矩阵方法

本文用微分算子矩阵方法讨论了一类广义动态系统的结构性质,并且用微分算子多项式 矩阵的系数阵,给出了各类动态系统能控(观)性的直接判据.它是用微分算子矩阵方法研究 广义动态系统的开端.     

改进的正则化模型在图像恢复中的应用

目的 由拟合项与正则项组成的海森矩阵,如果不具有特殊结构,其逆矩阵计算比较困难,为克服此缺点,提出一种海森矩阵可分块对角化的牛顿投影迭代算法。方法 首先,用L₂范数描述拟合项,用自变量是有界变差函数的复合函数刻画正则项,建立能量泛函正则化模型。其次,引入势函数,将正则化模型转化为增广能量泛函。再次,构造预条件矩阵,使得海森矩阵可分块对角化。最后,为防止牛顿投影迭代算法收敛到局部最优解,采用回溯线性搜索算法和改进的Barzilai-Borwein步长更新准则使得算法全局收敛。结果 针对图像去模糊正则化模型容易使边缘平滑和产生阶梯效应“两难”问题,提出一种新的正则化模型和牛顿投影迭代算法。仿真结果表明,“两难”问题通过本文算法得到了很好的解决。结论 与其他正则化图像去模糊模型相比,本文算法明显改善图像的质量,如有效地保护图像的边缘,抑制阶梯效应,相对偏差和误差较小,较高的峰值信噪比和结构相似测度。     

Transfer matrix method for linear multibody system

A new method for linear hybrid multibody system dynamics is proposed in this paper. This method, named as transfer matrix method of linear multibody system (MSTMM), expands the advantages of the traditional transfer matrix method (TMM). The concepts of augmented eigenvector and equation of motion of linear hybrid multibody system are presented at first to find the orthogonality and to analyze the responses of the hybrid multibody system using modal method. If using this method, the global dynamics equation is not needed in the study of linear hybrid multibody system dynamics. The MSTMM has a small size of matrix and higher computational speed, and can be applied to linear multi-rigid-body system dynamics, linear multi-flexible-body system dynamics and linear hybrid multibody system dynamics. This method is simple, straightforward, practical, and provides a powerful tool for the study on linear hybrid multibody system dynamics. This method can be used in the following: (1) Solve the eigenvalue problem of linear hybrid multibody systems. (2) Obtain the orthogonality of eigenvectors of linear hybrid multibody systems. (3) Realize the accurate analysis of the dynamics response of linear hybrid multibody systems. (4) Find the connected parameters between bodies used in the computation of linear hybrid multibody systems. A practical engineering system is taken as an example of linear multi-rigid-flexible-body system, the dynamics model, the transfer equations and transfer matrices of various bodies and hinges; the overall transfer equation and overall transfer matrix of the system are developed. Numerical example shows that the results of the vibration characteristics and the response of the hybrid multibody system received by MSTMM and by experiment have good agreements. These validate the proposed method.     

离散型模糊系统的稳定线性监督控制设计

在对现有的T-S型模糊系统的稳定性结果进行 分析的基础上,研究了状态空间形式下离散型模糊系统在子空间上的线性分解,基于该线性 分解设计一线性监督控制器使模糊闭环系统稳定,从而用简单的线性系统理论完成了对复杂 非线性系统的控制．仿真结果证明了该线性监督控制器的有效性．     

Fuzzy modeling and control of an engine air inlet with exhaust gas recirculation

The purpose of this paper is to present an original fuzzy modeling method applied to a highly non- linear physical system, an engine air inlet with exhaust gas recirculation. This system is modeled with fuzzy logic rules of the Takagi–Sugeno type. The rule base switches between local linear models defined in the whole state space. The control objective is to preserve the linear behavior of the closed-loop system in all operating conditions. To reach this objective, the linear control tools are applied to each local linear model. The fuzzy model rule-base structure is then used to switch between local controllers.     

Set Invariance Conditions for Singular Linear Systems Subject to Actuator Saturation

In this note, we establish a set of conditions under which an ellipsoid is contractively invariant with respect to a singular linear system under a saturated linear feedback. These conditions can be expressed in terms of linear matrix inequalities, and the largest contractively invariant ellipsoid can be determined by solving an optimization problem with LMI constraints. With the feedback gain viewed as an additional variable, this optimization problem can be readily adapted for the design of feedback gain that results in the largest contractively invariant ellipsoid. Moreover, in the degenerate case where the singular linear system reduces to a regular system, our set invariance conditions reduce to the existing set invariance conditions for normal linear systems.     

Quadratic stabilizability of uncertain linear systems: Existence of a nonlinear stabilizing control does not imply existence of a linear stabilizing control

This note is concerned with the problem of stabilizing an uncertain linear system via state feedback control. An uncertain system which admits a stabilizing state feedback control and some associated quadratic Lyapunov function is said to be quadratically stabilizable. In a number of recent papers, conditions are given under which quadratic stabilizability via nonlinear control implies quadratic stabilizability via linear control. These papers restrict the manner in which the uncertain parameters are permitted to enter structurally into the state equation in order to establish this result. This note presents an example which shows that this implication is not true for more general uncertain linear systems. To this end, we describe an uncertain linear system which is quadratically stabilizable via nonlinear control but not quadratically stabilizable via linear control.     

有机化学结构的线型表示

本线型表示法以官能团为基本单元，根据ＩＵＰＡＣ有机化学命名原则及专家系统对表示法的要求，制定了比较简单的定序法则，本方法已应用于我所的专家系统ＥＳＣＳ中。     

Tube-based robust MPC for linear time-varying systems with bounded disturbances

In this paper, a novel synthesis approach for tube-based robust MPC is proposed. A novel feature is the fact that the proposed tube-based robust MPC algorithm can deal with both time-varying parameter and bounded disturbance. The proposed control law is the linear combination of two components. The first component steers the state of the nominal linear time-varying system to the origin. The second component keeps the state at each time step of the linear time-varying system with bounded disturbance within a tube whose center is the state of the nominal linear time-varying system. Finally, the state of the linear time-varying system with bounded disturbance is kept within a tube whose center is at the origin so robust stability is guaranteed. Satisfaction of the state and control constraints is ensured by employing tighter constraint sets for the nominal linear time-varying system. The computational burdens are the same as those in the case of the nominal linear time-varying system.     

工业CT用驻波电子直线加速器测试系统的研制

从验收直线加速器的角度出发,设计了直线加速器测试系统,详细阐述了测试系统与直线加速器的电气连接关系,以及系统的各组成模块,实现了分项系统的质量监控操作.     

Sign-Stable Solutions of Column-Vague Linear Equation Systems

It is well-known that the set of sign-stable solutions of an interval linear equation system can be described by a system of linear inequalities. In this paper, an analogue of the mentioned result for a more general type of inaccurate linear equation system is derived.     

Improving stability margins via dynamic-state feedback for systemswith constant uncertainty

It is well known that if a linear system with time-varying uncertainty in the system matrix and/or the input connection matrix is quadratically stabilizable by linear dynamic state feedback, then it is also quadratically stabilizable by linear static state feedback. In this paper, we provide an example of a system with unknown constant real uncertainty which is stabilizable by a linear, dynamic-state feedback controller but not by a static-state feedback controller