L1-norm method for multi-baseline InSAR phase unwrapping

Multi-baseline phase unwrapping is a critical processing procedure of multi-baseline synthetic aperture radar interferometry (InSAR). However, it has a disadvantage that it is not robust to noise. In order to solve this problem, in this paper, an L¹-norm based single-baseline phase unwrapping method is proposed. By using the L¹-norm optimization model, the relation among interferograms obtained by multi-baseline InSAR is combined in the conventional signle-baseline L¹-norm phase unwrapping optimization model with this algorithm. Finally, simulated experiments demonstrate that this method has a better accuracy on phase unwrapping results and that it can be applied to measuring the complex terrain.     

Method for inpainting blind images using the game and L0 constraint

Image inpainting is the process of restoring the original image from the observed image with missing pixels using the prior information on the original image.Most image inpainting models assume that the missing areas of the image are known.However,inpractical applications,the information on these missing areas is difficult to obtain directly.In order to solve this problem,a new image inpainting model is established by using the sparse priori of L₀ norm and game theory.The new model is suitable for the two cases of known and unknown image missing areas.According to the structure of the objective function,an effective proximal alternating direction method of multipliers and a game-based alternating framework are proposed to solve the corresponding minimization problem,and the convergence of the model under certain conditions is analyzed.Compared with the existing inpainting models,numerical experiments show that the models and algorithms proposed can lead to better results and robustness insubjective and objective quality evaluation than the image inpainting methods available.     

Robust L1 model reduction for stochastic time-delay systems

This paper investigates the problem of robust L1 model reduction for continuous-time uneertain stochastie time-delay systems. For a given mean-square stable system, our purpose is to construct reduced-order systems, such that the error system between these two models is mean-square asymptotically stable and has a guaranteed L1(also called peak-to-peak) performance. The peak-to-peak gain criterion is first established for stochastic time-delay systems, and the corresponding model reduction problem is solved by using projection lemma. Sufficient eonditions are obtained for the existence of admissible reduced-order models in terms of linear matrix inequalities (LMIs) phls matrix inverse eonstraints. Since these obtained conditions are not expressed as strict LMls, the cone complementarity linearization (CCL) method is exploited to cast them into nonlinear minimization problems subject to LMI constraints, which can be readily solved by standard numerical software. In addition, the development of reduced-order models with special structures, such as the delay-free model, is also presented. The efficiency of the proposed methods is demonstrated via a numerieal example.     

圆形区域极点约束下的δ算子时滞系统鲁棒L2-L∞控制

研究了δ算子线性参数不确定时滞系统具有圆形区域极点约束的鲁棒L2-L∞控制问题。根据矩阵理论,以矩阵不等式形式给出δ算子时滞系统极点位于圆形区域内的一个充分条件。针对受扰的δ算子线性参数不确定时滞系统,利用Lyapunov稳定性理论,提出满足圆形区域极点约束的最优鲁棒L2-L∞状态反馈控制器的设计方法,控制器可以确保对于所有的容许不确定性,δ算子闭环时滞系统的极点都位于稳定域内的指定圆形区域中,并使系统的鲁棒L2-L∞性能指标尽可能小。数值算例验证了设计方法的可行性和有效性。     

一种基于L1稀疏正则化和非负矩阵分解的盲源信号分离新算法

针对线性混合模型下的盲源分离这一反问题,提出了一种结合迭代正则化和非负矩阵分解的交替最小化算法．首先把该问题转化为有界约束的二次规划,然后采用了一种自适应BB(Barzilai-Borwein)步长的投影梯度算法来求解．该方法不仅可减少存储量,提高算法速度,而且还很好地刻画了信号的稀疏性和独立性．理论分析和数值试验都验证了该方法的有效性,对混合的二维图像能提高分离的信干比．     

Robust simultaneous tracking and stabilization of wheeled mobile robots not satisfying nonholonomic constraint

A robust unified controller was proposed for wheeled mobile robots that do not satisfy the ideal rolling without slipping constraint.Practical trajectory tracking and posture stabilization were achieved in a unified framework.The design procedure was based on the transverse function method and Lyapunov redesign technique.The Lie group was also introduced in the design.The left-invariance property of the nominal model was firstly explored with respect to the standard group operation of the Lie group SE(2).Then,a bounded transverse function was constructed,by which a corresponding smooth embedded submanifold was defined.With the aid of the group operation,a smooth control law was designed,which fulfills practical tracking/stabilization of the nominal system.An additional component was finally constructed to robustify the nominal control law with respect to the slipping disturbance by using the Lyapunov redesign technique.The design procedure can be easily extended to the robot system suffered from general unknown but bounded disturbances.Simulations were provided to demonstrate the effectiveness of the robust unified controller.     

简化球谐近似与拉普拉斯正则化的FMT成像方法

荧光分子断层成像作为一种先进的光学分子影像,可以有效重建小动物体内荧光团的浓度和三维空间分布信息,实现肿瘤的早期检测.为了提高重建的图像性能,针对扩散模型只适合高散射低吸介质的局限性,采用基于辐射传输方程的简化球谐近似模型进行前向模拟,同时为克服重建过程的病态性,应用一种融合结构信息的拉普拉斯正则化方法进行图像重建.数值仿真实验结果表明,该方法能够获得较高质量的重建图像,尤其对于小荧光团和多荧光团成像.     

基于PSO-DE和LMI的鲁棒静态输出反馈控制

在多目标控制框架下,针对连续多面体不确定系统,提出了一种混合算法来解决鲁棒静态输出反馈控制问题。为了计算静态输出反馈增益,通过把粒子群优化(PSO)和差分进化(DE)的混合算法与线性矩阵不等式(LMI)方法相结合,求解具有双线性矩阵不等式(BMI)约束的优化问题。PSO-DE混合算法用来得到控制器的样本,LMI方法用来最优化系统的性能指标。以混合H2/H∞控制问题为例,给出了一种鲁棒多目标静态输出反馈控制求解的算法。仿真结果表明,与以往的迭代法和DE-LMI算法相比,提出的PSO-DE/LMI混合算法提高了收敛速度和精度。     

烟囱和逆温高度对污染物扩散的作用

采用高烟囱扩散稀释的方法。可以使大气污染物向更高、更广的范围扩散。姚电公司坑口发电厂把100m的矮烟囱改为240m高的烟囱，地面SO2浓度的年平均值减少为原来的1／5．2到1／7．5。减轻了局部地区的空气污染。     

应用动态逆和三时标分离的飞航导弹过载控制离散化设计

目的是选用普通舵系统来设计一种低成本高性能飞航导弹过载数字控制系统。这种情况下舵系统的动态特性将不能忽略。假设舵系统具有一阶动态特性,导弹的单通道(例如纵向通道)成为一个三阶的被控对象。应用三时标分离的方法将导弹动力学(含舵系统)分离为3个一阶的动力学子系统,这3个子系统分别对应于过载层(慢速子系统)、角速度层(中速子系统)和角加速度层(快速子系统),对这3个子系统分别采用Adams-Bashforth数值方法进行离散化、并进行离散化动态逆控制设计,应用李雅普诺夫综合法,分别设计出期望的慢、中、快离散动力学子系统。给出了各子系统带宽参数的选择方法。仿真结果验证了本文方法的正确性和有效性。     

在L1[0,1]中有关向量值函数强囿变与可导性的一个注记

用简单的例子说明了L     

地-月系L_1和L_2点间转移轨道设计

以Richardson三阶近似解作为初值,采用微分修正的方法,设计了Halo轨道。然后基于不变流形理论和庞加莱截面方法,设计了不同拉格朗日点间转移轨道。仿真结果表明,提出的方法可以得到耗能较低的转移轨道。     

T C-1-HPV16 L1细胞模型与动物模型的建立与评价

为了解决人乳头瘤病毒16型L1蛋白(HPV16L1)为主要靶点的疫苗缺乏肿瘤模型细胞来验证疫苗的免疫效果的问题,构建了一个细胞模型并可以利用此细胞在实验动物体内形成肿瘤,用于以HPV16L1为主要靶点疫苗的验证实验。利用这个模型细胞或肿瘤模型可以在体内外检测疫苗的免疫学性质和保护功效。首先,利用聚合酶链式反应(polymerase chain reaction,PCR)的方法获得目标基因HPV16L1的基因序列并连接到载体质粒中,将质粒转染到细胞TC-1后在杀稻瘟菌素抗性压力筛选下获得稳定表达HPV16L1的细胞株。对TC-1和TC-1-HPV16L1两种细胞的生长增殖和成瘤特性进行比较发现,外源基因的加入对细胞特性没有影响。通过体外杀伤实验证实细胞TC-1-HPV16L1能够被HPV16L1靶点疫苗免疫过的小鼠脾淋巴细胞杀伤。实验动物被疫苗免疫后,进行攻瘤实验发现疫苗只对TC-1-HPV16L1组具有保护作用。综上,在本研究中成功地构建了可以检测HPV16L1疫苗的抑瘤效果的模型细胞TC-1-HPV16L1,为HPV疫苗的研究提供了一个模型细胞。     

采用相关函数的OFDM雷达通信共享信号处理算法

针对脉冲体制下正交频分复用雷达-通信共享信号处理问题,提出一种基于相关函数的共享信号处理算法．首先对回波信号补偿脉间多普勒频移;然后与发射信号取相关并进行积累;最后对相关函数取模值平方,得到目标函数在距离多普勒域的二维输出．研究了通信调制对算法的影响,推导了算法的主瓣均值与旁瓣均值,并分析了多普勒对主瓣峰值均值以及旁瓣均值的影响．仿真实验验证了文中算法的正确性,并确定了算法的应用范围．     

基于L1范数和最小软阈值均方的目标跟踪算法

基于传统稀疏表示的目标跟踪算法无法解决跟踪过程出现的遮挡及运动模糊等问题,提出一种基于L₁范数和最小软阈值均方的目标跟踪算法。首先用主成分分析(principal component analysis, PCA)基向量建模跟踪目标的表观变化,同时对表示系数进行L₁范数约束;其次对误差项采用最小软阈值方法进行显示求解,同时对观测模型的更新上考虑跟踪目标的遮挡因素;最后在贝叶斯框架下搭建目标跟踪算法。在14个具有挑战性的跟踪视频上的试验结果表明:与其他算法相比,本研究能够克服跟踪过程中遮挡、角度变化、尺度变化、光照变化等影响跟踪性能的因素,具有较高的平均覆盖率和较低的平均中心点误差。     

利用EXEC功能加载并执行程序模块的实现方法

提出利用ＤＯＳ系统提供的ＥＸＥＣ功能，在一个应用程序中直接装入并执行若干个可执行程序模块的实现方法．用该方法可将大型软件系统中若干子模块集合起来，任意调用执行，使系统结构严谨、功能清晰、操作方便．文中给出了实用源程序．     

An evaluation of deep thin coal seams and water-beating/resisting layers in the quaternary system using seismic inversion

Non-liner wave equation inversion, wavelet analysis and artificial neural networks were used to obtain stratum parame-ters and the distribution of thin coal seams. The lithology of the water-bearing/resisting layer in the Quaternary system was also predicted. The implementation process included calculating the well log parameters, stratum contrasting the seismic data and the well logs, and extracting, studying and predicting seismic attributes. Seismic inversion parameters, including the layer velocity and wave impedance, were calculated and effectively used for prediction and analysis. Prior knowledge and seismic interpretation were used to remedy a dearth of seismic data during the inversion procedure. This enhanced the stability of the inversion method. Non-linear seismic inversion and artificial neural networks were used to interpret coal seismic lithology and to study the wa-ter-bearing/resisting layer in the Quaternary system. Interpretation of the 1-2 m thin coal seams, and also of the wa-ter-bearing/resisting layer in the Quaternary system, is provided. The upper mining limit can be lifted from 60 m to 45 m. The pre-dictions show that this method can provide reliable data useful for thin coal seam exploitation and for lifting the upper mining limit, which is one of the principles of green mining.     

基于C形弹性管的光纤光栅压力位移传感测量

设计了一种基于C形弹性管的光纤布喇格光栅传感结构．用管内过剩压力使弹性管的自由端产生位移和管表面产生的应力对光纤布喇格光栅反射波长进行调谐．得到了光纤布喇格光栅反射波长变化对应于压力和自由端位移的线性关系．在0～6MPa的压力范围内,光纤布喇格光栅反射波长随压力和位移均呈线性变化且压力和位移的传感灵敏度分别达到0.0305nm/MPa和0.0359nm/mm,线性调谐范围分别为0.183nm和0.215nm,波长分辨率分别为3.05pm和0.718pm．     

最小L1范数实现周期非均匀采样与重构研究

根据周期非均匀采样需要多个采样通道的特点,利用联合子空间理论将采样与重构转换为矩阵向量运算。结合最小L1范数算法,提出了一种针对稀疏信号的周期非均匀采样与重构方法,分析了最小L1范数算法在周期非均匀采样系统中的完整重构条件。最后,以多带正弦信号为例,分别从可完整重构概率和系统整体验证两个方面证明了该方法能够实现稀疏信号的采样与重构。     

标记理论与母语迁移关系的研究

从语言标记性的角度研究标记理论与母语正负向迁移的关系,论述该研究成果对第二语言课堂教学的几点启示,最后指出该研究领域今后尚待深入探讨的一些问题.