Face recognition using elastic local reconstruction based on a single face image

In this paper, we propose a new face recognition algorithm based on a single frontal-view image for each face subject, which considers the effect of the face manifold structure. To compare two near-frontal face images, each face is considered a combination of a sequence of local image blocks. Each of the image blocks of one image can be reconstructed according to the corresponding local image block of the other face image. Then an elastic local reconstruction (ELR) method is proposed to measure the similarities between the image block pairs in order to measure the difference between the two face images. Our algorithm not only benefits from the face manifold structure, in terms of being robust to various image variations, but also is computationally simple because there is no need to build the face manifold. We evaluate the performance of our proposed face recognition algorithm with the use of different databases, which are produced under various conditions, e.g. lightings, expressions, perspectives, with/without glasses and occlusions. Consistent and promising experimental results were obtained, which show that our algorithm can greatly improve the recognition rates under all the different conditions.     

一种高动态范围图像可视化算法*

提出的自适应HDR图像可视化算法中,输入图像被分解为基本层和细节层.该算法将整体明暗效果的显示看做整体问题,对表示亮度的基本层采用基于整体统计信息的直方图调整算法处理;可视细节信息的保持作为局部问题,算法采用自适应细节增强算法处理细节层.通过定义映射图对细节增强后的图像进行最终映射,将两方面结合起来得到最终结果.实验结果表明,该算法能对HDR图像进行较高视觉质量的显示.     

以跨学科架构分析与认识城市规划设计空间

在城市设计过程中 ,需要首先对设计的对象进行形象化的分析和研究 ,从而形成关于城市环境空间设计的规定性、指导性导则 .为此 ,在城市规划设计中不同领域的人基于各自的学科领域知识及应用背景以不同的角度去审视分析城市空间 ,从而提供城市空间不同层次不同角度的参考信息 .要形成城市设计空间全面、形象、准确、具体的认识 ,以利于城市设计从整体上去把握城市空间 ,这就需要进行多种信息资料整合 ,首先面临的就是从跨学科的角度去认识和把握城市空间 ,将原有信息在跨学科的领域分析中得到更大的发挥 .通过城市可视视觉景观分析、城市光环境分析及城市风环境分析 ,对在不同层面上所提供的城市环境空间信息进行分析 ,从而探讨基于多学科的信息整合、信息再生、信息处理与分析所面临的机遇与挑战 .     

Static Output Feedback Stabilization: An ILMI Approach

In this note, the static output feedback stabilization problem is addressed using the linear matrix inequality technique. A necessary and sufficient condition for static output feedback stabilizability for linear time-invariant systems is derived in the form of a matrix inequality. The extension of the result to H_∞ control is studied. An iterative LMI (ILMI) algorithm is proposed to compute the feedback gain. Numerical examples are employed to demonstrate the effectiveness and the convergence of the algorithm.     

AN EXACT METHOD FOR ANALYSING ELASTODYNAMIC RESPONSE OF ANISOTROPIC LAMINATES TO LINE LOADS

SUMMARY

An exact matrix formulation for analysing the responses of anisotropic laminated plates subjected to line loads is presented. In this formulation, a Fourier transform with respect to the horizontal spatial co-ordinate is employed and wave modes for a layer are obtained from an eigenvalue equation. Displacements in the wavenumber domain are obtained by using boundary conditions. A complex path is used and a new adaptive quadrature scheme is proposed to evaluate the inverse Fourier integration to obtain the displacement in the frequency domain. An exponential window method is used to compute responses in the time domain. Complex paths are investigated in detail to improve the efficiency for computing the responses of the plates for both pure and viscoelastic materials in both time and frequency domains. Numerical examples are presented to illustrate the present method.     

Design of stochastic discrete time linear optimal regulators Part II. Extension and computational procedures

Using the relationship established in Part I, computational procedures are formulated for implementing stochastic optimal regulators based on the CARMA model. The state space configurations (including both the implicit delay and explicit delay models) allow the consideration of general quadratic cost functions, in particular the receding horizon N-stage cost function ; a simple example is used to illustrate various design steps required. The characteristics of the implicit delay and explicit delay models are exploited to give a computationally efficient scheme for system with large control delay     

一种基于分形码和模型约束的图像放大算法

图像放大技术在众多研究领域中有着重要的应用.本文提出一种基于分形码和模型约束的图像放大算法,分形码能够包含图像的空间信息和图像本身的自相似信息,模型约束能够有效的限制放大引入的误差.我们首先对图像采用多种值域块分割方案计算得到多组分形码,并由此得到多个放大图像,然后对放大图像进行平均,从而降低编码误差,最后采用约束模型对放大图像进行修正.实验结果表明,利用本文的方法可以大大提高放大图像的PSNR.     

面向头肩序列图像的质量可精细扩展视频编码方法

FGS编码方法具有细粒度的可扩展能力,能很好地适应网络带宽的动态变化,被认为是一种适合于网络视频传输的编码方案.但现有的MPEG-4 FGS编码标准效率低,限制了其进一步的推广应用.因此,本文面向视频应用中常见的头肩序列图像,实现了一种质量可精细扩展的视频编码方法.该方法采用H.26L对基本层进行编码,采用基于DCT变换的SPIHT方法对原始图像与基本层重建图像之间的残差进行编码得到增强层的码流.然后将复杂背景下的人脸检测与跟踪技术与选择性增强技术结合起来,对人脸区域优先编码.实验结果表明,该方法不仅编码效率高于现有的MPEG-4 FGS标准,码流具有可精细扩展的特性,还可以选择性地提高人脸区域重建图像的主观感受水平.     

圆柱振荡流中的斜向涡街

本文用数字粒子成像测速仪 (DPIV) ,对圆柱体在静水中作正弦振动而产生的振荡流场进行了实测研究。通过相位锁定技术和互相关分析法 ,分别获得了圆柱体在振动周期中 8个不同相位的流场速度矢量及涡量强度等值线分布。实测表明 ,当 KC =12 时 ,圆柱振荡尾流中将存在一个有明显周期性且较规则的斜向涡街 ,涡街主要由一股较强的二次流及其两侧的非对称的涡对构成 ,涡街与圆柱体振动方向成± 45°夹角。而当KC =6.2 8时 ,由于吸附于柱体的涡对未能脱离柱体进入其尾流 ,因而无涡街产生。文中还分析和讨论了斜向涡街产生的机理并对振荡流中柱体受力情况进行了量测。受力测量结果表明 :当斜向涡街稳定时 ,圆柱体各向受力差异不大 ;但在涡街方向转变期间 ,柱体沿斜向的受力却明显大于沿运动方向的阻曳力