基于三维模型的多姿态人脸识别

提出了一种利用三维人脸模型匹配二维人脸图像的分层人脸识别方法和基于模糊数学的人脸姿态角度估计算法.对多姿态二维图像进行姿态空间划分,利用主成分分析方法(PCA)形成多姿态特征脸.识别过程首先估计测试图像姿态和模糊姿态角,在估计的姿态空间内采用基于PCA的方法进行第一层识别得到候选个体,然后利用候选个体的三维模型结合模糊姿态角产生虚拟图像,利用相关进行第二层识别.实验结果表明,该方法对姿态的变化有较好的鲁棒性.     

基于Gabor小波的人脸表情识别

提出通过提取人脸表情图像的Gabor特征,结合二次降维的方法,进行人脸表情识别.针对Gabor特征提取后维数变高,冗余很大的特点,先对高维特征进行采样,再引入二维PCA算法对Gabor特征进行选择,以达到降维的目的.然后采用基于模糊积分的多分类器联合的方法对7种表情进行融合识别.在JAFFE库上进行测试的结果验证了该算法的有效性,与2DPCA算法及传统特征提取算法相比,本文算法取得了较高的识别速度和精确度.该算法能更有效的提取反映表情状态的特征.     

基于改进变分自编码器的多物理域多模态信息融合方法研究

多物理域多模态信息融合具有复杂、高维度、计算量大、鲁棒性差、异构数据处理难的特点,传统基于变分自编码器方法,由于采用单一的信息通道,缺乏对不同模态不同时频域空间信息交换,忽略了不同尺度的特征融合,造成生成结果质量较差。本文在变分自编码器的基础之上,加强了变分自编码器的信息流向,提出基于改进变分自编码器的多物理域多模态信息融合方法,使得融合结果更能反映不同物理域的观测真实性。同时对比了病态数据融合、彩色图像融合深度图像两种不同的多模态信息融合与传统算法效果,在频谱图的定性指标和PSNR/SSIM定量指标上,有明显提升。     

基于曲波系数加权融合的人脸识别

为了提高人脸识别率和缩短识别时间,研究了基于曲波变换的人脸识别技术。考虑到传统曲波变换无法将多尺度多方向的曲波特征进行最优表示且其特征维数过大的缺点,提出了一种基于自适应加权融合的曲波变换和独立分量分析(ICA)的人脸识别算法。该算法通过曲波变换提取原始人脸图像的最优尺度和方向上的曲波系数,并对这些特征系数进行多方向上的融合,根据类别可分离性的判据原则对融合后的系数进行加权,以减少特征数量,提高处理速度;通过独立分量分析降维,将这些特征投影到更具表达力的空间,以获取有效特征,减少冗余信息,便于最近邻分类器进行人脸识别。基于在奥利维帝研究实验室(ORL)人脸库、Yale B人脸库和AR人脸库对该算法进行了测试,结果表明,其识别率分别达到98%、97%和98.57%,单幅图片的识别时间分别为65.43,158.94和20.37ms,从而验证了其实用性。     

基于局部Gabor相位特征融合的人脸识别

本文提出了一种提取人脸图像的局部Gabor相位特征,结合Fisher线性判别式,通过特征融合进行人脸识别的方法.该方法首先利用Gabor滤波良好的空间位置与方向选择特性,采用四个频率六个方向的Gabor滤波器对图像进行滤波,然后根据Daugman方法采用局部XOR算子提取滤波图像的局部Gabor相位特征,组成特征图像,最后通过Fisher判别式对每个频率和方向下的特征图像进行降维,融合降维后的特征,采用最近邻分类器进行识别.该方法通过在两个数据库中的实验,证明了较主成分分析法,Fisher线性判别式方法以及Gabor幅值特征融合识别方法更好的识别性能.     

Shearlet多方向自适应加权融合的稀疏表征人脸识别

针对传统稀疏表征分类器只有在训练样本足够多时才会对特征变化不敏感的缺点,提出一种Shearlet多方向自适应加权融合的稀疏表征人脸识别算法。为了提取局部方向信息并降低特征维数,首先利用Shearlet变换对图像进行多尺度、多方向分解,获得子带系数矩阵,然后根据子带系数矩阵方差的大小对同一尺度的方向子图按主方向排序,利用子带系数矩阵的能量和均值特征对排序后的人脸子图进行加权融合,最后为了使得表征系数矢量具有更为显著的稀疏性,进一步利用融合特征构造字典。在ORL、FERET和YALE人脸库中做了多组实验,结果表明,该方法能增强对外界环境变化的鲁棒性,同时可以提高人脸的识别率。     

基于iOS的人脸局部特征检测研究

基于生物特征识别技术与智能移动设备,在苹果公司的iOS智能操作平台下研究手机人脸局部特征检测方法.在YCbCr色彩空间中,通过高斯模型对人脸肤色建模,并对人脸图像进行滤波、二值化等优化处理,根据图像像素投影判断出人脸区域.采用Canny算子对图像进行边缘检测,对变换后的图像水平积分投影,根据投影曲线的波峰标记出人脸特征位置.经实验验证,该方法具有可行性,可以运行在基于iOS平台的移动设备上.     

利用两类投影方法进行特征融合的人脸识别

提出了利用两类投影抽取特征、用并行策略融合特征进行人脸识别的新方法。先用一维的基于向量的投影抽取一组特征，再用基于二维的图像投影的方法抽取一组特征，用复向量将样本的两组特征向量组合在一起，在复向量空间分析主分量(CPCA)，抽取人脸图像的鉴别特征。在FERET人脸库上的实验结果表明，该方法的识别性能比用单个特征有10%左右的提高。     

一种改进的局部三值模式的人脸识别方法

为了更好的描述人脸特征,提出了一种基于不同尺度像素块及自适应阈值的局部三值(LTP)模式方法.该方法首先将图像分为若干个子区域,采用自适应阈值并基于不同尺度的像素块提取每个子区域的LTP纹理直方图,然后将得到的每个子区域的直方图连在一起并经过主成分分析(PCA)降维处理得到特征向量.在人脸数据库上进行的实验证明,应用该方法进行人脸特征提取并结合最近邻分类法得到了较高的识别率.     

基于局部纹理特征的三维掌纹识别研究

近年来,自动掌纹识别方法的研究吸引了越来越多的关注,已有的工作主要集中于二维掌纹识别。然而,二维掌纹图像存在着易伪造、抗噪能力差的缺陷,实际应用中会带来潜在的安全隐患。因此,三维掌纹识别被视为一种可行的解决方案来进一步提高识别的性能。基于局部纹理特征,本文提出一种有效的三维掌纹识别方法。该方法首先利用形状指数来描述三维掌纹的局部几何特征,接着提取形状指数图像的局部三值模式以及Gabor小波特征,最后在匹配分数层次上对这两种互补的局部纹理特征进行融合,随后的实验证明了融合特征较单独特征要好。在香港理工三维掌纹数据库上的实验结果表明,本文方法在识别率上要优于目前流行的其它三维掌纹识别方法,从而验证了本文方法的有效性。     

检定和校准证书的异同与应用

本文介绍了检定和校准以及证书的两点相同、五点不同之处,说明了对检定证书和校准证书的正确应用。     

Synthesis and luminescent properties of alkali-metal and ammonium fluorosulfatozirconates and fluorosulfatohafnates

We have synthesized a variety of alkali-metal and ammonium fluorosulfatometallates (titanates, zirconates, and hafnates). The alkali fluorosulfatozirconates and fluorosulfatohafnates have been shown to exhibit efficient roentgenoluminescence (RL) in the UV through visible spectral region, with a maximum at 390–440 nm. Their RL spectra depend significantly on their composition (cation, anion, and water content), coordination of KF and K₂SO₄, and relative amounts of fluorine and SO₄ groups. We have examined the effect of heat treatment on the RL of these compounds. The rubidium and cesium fluorosulfatozirconates Rb₃Zr₂F₉SO₄ · 2H₂O, Cs₂ZrF₂(SO₄)₂ · 2H₂O, Cs₈Zr₄F₂(SO₄)₁₁ · 16H₂O, and Cs₂ZrF₄SO₄ offer the most efficient RL.     

Heat and Mass Transfer and Modeling and Prediction of Environmental Catastrophes

Basic definitions and concepts of the physicomathematical theory of natural catastrophes are given. Possibilities of mathematical modeling of natural and technogenic catastrophes are discussed in the context of the theory of heat and mass transfer and the mechanics of reacting media. The importance of taking into account conjugate heat and mass exchange in modeling catastrophes is emphasized. A formula for evaluating the probability of a collisional catastrophe is given.     

Multi-ferroic and magnetoelectric materials and interfaces

The existence of multiple ferroic orders in the same material and the coupling between them have been known for decades. However, these phenomena have mostly remained the theoretical domain owing to the fact that in single-phase materials such couplings are rare and weak. This situation has changed dramatically recently for at least two reasons: first, advances in materials fabrication have made it possible to manufacture these materials in structures of lower dimensionality, such as thin films or wires, or in compound structures such as laminates and epitaxial-layered heterostructures. In these designed materials, new degrees of freedom are accessible in which the coupling between ferroic orders can be greatly enhanced. Second, the miniaturization trend in conventional electronics is approaching the limits beyond which the reduction of the electronic element is becoming more and more difficult. One way to continue the current trends in computer power and storage increase, without further size reduction, is to use multi-functional materials that would enable new device capabilities. Here, we review the field of multi-ferroic (MF) and magnetoelectric (ME) materials, putting the emphasis on electronic effects at ME interfaces and MF tunnel junctions.     

CellML and associated tools and techniques

We have, in the last few years, witnessed the development and availability of an ever increasing number of computer models that describe complex biological structures and processes. The multi-scale and multi-physics nature of these models makes their development particularly challenging, not only from a biological or biophysical viewpoint but also from a mathematical and computational perspective. In addition, the issue of sharing and reusing such models has proved to be particularly problematic, with the published models often lacking information that is required to accurately reproduce the published results. The International Union of Physiological Sciences Physiome Project was launched in 1997 with the aim of tackling the aforementioned issues by providing a framework for the modelling of the human body. As part of this initiative, the specifications of the CellML mark-up language were released in 2001. Now, more than 7 years later, the time has come to assess the situation, in particular with regard to the tools and techniques that are now available to the modelling community. Thus, after introducing CellML, we review and discuss existing editors, validators, online repository, code generators and simulation environments, as well as the CellML Application Program Interface. We also address possible future directions including the need for additional mark-up languages.     

热交换器的分类及优缺点分析

热交换器是将不同温度介质之间的热量通过热传导的形式,由高温介质传递给低温介质,使介质达到生产所需温度的工艺设备,也可作为一种节能设备使用.通过对不同热交换器的结构分析,总结不同热交换器的优缺点、适用环境,为生产工艺设计人员及设备制造单位在选择可降低能耗、提高效率的设备上提供参考.     

The shape and stability of wall-bound and wall-edge-bound drops and bubbles

The behavior of wall-bound drops and bubbles is fundamental to many natural and industrial processes. Key characteristics of such capillary systems include interface shape and stability for a variety of gravity levels and orientations. Significant solutions are in hand for axisymmetric pendent drops for a variety of uniform boundary conditions along the contact line with gravity acting normal to a planar wall. The special case of a wall-bound drop or bubble that is also pinned at an edge (i.e. a ‘wall-edge-bound’ drop) is considered here where numerical solutions are obtained for interface shape and stability as functions of drop volume, contact angle, fluid properties, and uniform gravity vector. For a semi-infinite zero-thickness planar wall (plate), a critical contact angle is identified below which wall-edge-bound drops are always stable. The critical contact angle is computed as a function of the gravity vector. The numerical procedure, which makes no account for contact angle hysteresis, predicts that such wall-edge-bound drops are unconditionally unstable for any gravity field with a component that is tangent to the wall while inwardly normal to the edge. Select experiments are conducted that support the conclusions drawn from the numerical results.