基于BP神经网络的人脸识别系统研究

本文设计了一种基于BP神经网络的人脸识别系统,并对其进行了性能分析.该系统首先利用离散小波变换获取包含人脸图像大部分原始信息的低频分量,对图像数据进行降维;再由PCA算法对人脸图像进行主成分特征提取,进一步降低图像数据的处理量;最后使用经过训练后的BP神经网络对待测人脸进行分类识别.详细介绍了离散小波变换、PCA特征提取以及BP神经网络分类设计.通过系统仿真实验与分析发现:人脸特征的提取是该系统的关键;同时,由于人脸灰度信息的统计特征与有监督训练BP神经网络分类器,使该系统只在固定类别,并且光照均匀的人脸识别应用场景中具有较高的识别准确率.因此,很难在复杂环境中应用.     

基于网络摄像头的活体人脸识别系统设计

针对当前监控系统平台体积大、功能单一、造价高等问题,文中基于海思3518E平台设计了一套在线活体人脸识别系统。该系统包含图像预处理、图像获取、人脸检测、人脸活体检测、人脸识别共5个部分,并针对传统算法在嵌入式平台的不足进行了改进与优化。系统通过摄像头采集的人脸图像对图像做预处理,为后续图像特征提取提供保障,利用扩展Haar特征训练分类器,并使用Adaboost算法级联分类器进行人脸检测,将检测到的人脸利用HSV和Ycbcr多色彩空间下提取的COALBP和LPQ融合特征训练SVM模型,并进行活体人脸检测。最后,对人脸图像分块提取LBP特征进行人脸识别,将识别结果通过微信小程序显示。实验结果表明,基于海思网络摄像头人脸识别系统的可行性,具有一定的实用价值。     

基于离散余弦变换的人脸识别方法

人脸图像的庞大信息量使其不适合于直接识别。提出用离散余弦变换处理人脸原始图像,得到降维的特征矢量,并结合前馈神经网络对人脸进行分类识别。通过对ORL人脸库多幅人脸图像的仿真实验表明,系统的识别率较高,且训练时间大大降低,是一种高效的识别方法。     

基于EHMM结合DWT与DCT的人脸识别

人脸识别系统可分为人脸检测,图像特征提取,人脸训练和人脸识别等部分,其中图像特征提取与人脸训练为主要组成部分,决定着系统的识别速度与准确性。人脸训练可为给定某人建立嵌入式隐马尔可夫模型来作为进行人脸图像识别的分类标准。人脸图像特征提取则运用离散小波分析来减少图像数据量,然后计算DCT变换系数矩阵,从而取得模型训练和识别中所需的图像特征。     

考虑光照鲁棒性的超分辨率人脸识别系统设计

为保障不同光照下低分辨率人脸的超分辨率识别精度与效率,设计了考虑光照鲁棒性的超分辨率人脸识别系统。通过包含DSP单元与ARM单元的控制器模块,驱动人脸视频采集模块。采集不同复杂光照的人脸视频信息并解析成视频帧后,预估视频帧序列的位移情况,恢复视频帧序列的超分辨率,融合超分辨率视频帧构成人脸图像样本。利用人脸特征提取模块补偿全部人脸图像样本复杂光照,并提取其LBP特征构成人脸库。通过人脸识别模块匹配人脸图像的LBP特征与人脸库,识别出超分辨率人脸图像。结果表明,该系统的光照鲁棒性人脸图像采集与人脸图像LBP特征提取两部分的实现效果均较好。可有效识别出背光、强光及弱光下的超分辨率人脸,识别效率较高,识别成功率能够达到96.7%,为光照鲁棒性人脸识别提供保障。     

基于小波分析与神经网络的人脸检测方法

本文设计了一种结合小波分析与神经网络优点的人脸检测方法.该方法主要包括两个阶段.在训练阶段首先借鉴图形学中的背景生成方法对AR人脸数据库中的人脸样本进行背景叠加;然后对经过预处理的训练样本进行小波分解,并将得到的小波系数输入精心设计的神经网络进行训练.在人脸检测阶段,通过将缩放后的图像的各个区域输入神经网络,由神经网络判断输入区域中是否包含人脸:在得到检测结果后,本文通过基于规则的方法以及基于SUSAN的方法进行人脸区域验证取舍与合并;最后通过实验结果的分析比较可以发现本文的方法不仅可以实现人脸区域的快速检测,而且不受光照变化以及噪声的影响.     

表情识别技术在铁路售票窗口中的应用

针对铁路窗口售票服务质量的问题,提出一种售票窗口服务质量的表情识别监测系统.该系统通过售票窗口外侧的摄像头检测到人脸图像时,表情监测系统每隔一定的时间就会通过安装在售票窗口内的摄像头获取监控范围内的帧图像信息,由表情识别监测系统对图像进行处理和识别,将识别后的结果进行数据统计.基于表情识别技术的监测系统在铁路售票窗口的应用,不仅能够提高售票员的服务质量,也能够让旅客在购票的过程中体验到舒适感.     

基于ICA与BP神经网络相结合的人脸识别研究

提出了独立成分分析和BP神经网络相结合的人脸识别方法。首先对人脸图像进行小渡分解。提取人脸图像的低频子带图像，然后用被立成分分析方法对低频子带图像进行特征提取，并用改进的BP神经网络时所提取的人脸特征进行分类识别。在AR人脸图像库中进行的实验表明，此方法取得了较高的识别率。     

彩色序列图像的人脸检测和识别系统

文中实现了彩色序列图像的人脸检测和识别的系统.所用到的关键性技术是肤色运动分析、主成分分析(PCA)和支撑向量机(SVM).首先根据彩色序列图像中人脸的色度特性、运动特性、几何特性和灰度分布特性完成人脸的检测工作;其次通过人脸模式之间的相关性进行主成分分析,提取并且选择特征,将所选择的特征训练SVM,最后用已经训练好的SVM完成对人脸的识别任务.系统算法结构遵循以下原则:先使用运算量少的简单方法尽可能减少搜索空间,然后在已经大大减少的空间中再用复杂方法处理,可以在保持高的检测和识别率的同时,提高系统响应速度.     

一种基于神经网络识别人脸进行内容审核的技术

介绍一种基于神经网络识别人脸并进行内容审核的技术.该技术通过构造神经网络实现人脸识别(或其他特征识别),并将识别后的特定人脸编码(特征码)存放在审核数据库中.将视频转化为单帧的图像(可以抽样稀释),输入神经网络获得编码,对比判断数据库里是否存在这个编码.如果存在此编码,将面孔用名字标识出来,从而实现由AI来审核是否有已知人脸(或其他特征)的视频内容.该种AI内容审核技术可以全面自动检查视频,不错过每个角落和细节,自动揪出乱象,打造健康的广告环境、影视环境.该技术的实施和应用,可以大大提升内容审核的工作效率.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.