模式识别

0306499工厂自动控制系统的说话人识别模块实现[刊]/雷鹏//电声技术.—2002,(10).—7～10(L)介绍了一个工厂自动控制系统中说话人识别模块的实现方法。采用实时语音端点检测算法作为语音端点检测算法,MFCC 和△MFCC 作为特征矢量,矢量量化和动态时间规整作为模式识别算法,以及系统软硬件的实现。参50306500基于 Trigger 的长距离语言模型[刊]/苏韬//计算机工程与应用.—2002,38(18).—59～61(L)     

基于MFCC0的语音端点检测方法

MFCC是语音识别中常用的特征参数，根据MFCC分量对语音端点的敏感性，提出利用平常舍去的识别特征参数分量MFCC0作为语音端点检测的参量．接着根据MFCC0的特性设计了一种新的端点检测方法，该方法简单且无需增加额外的计算量．实验结果表明，基于该方法的语音识别系统不仅可以通过端点检测大大压缩数据量，而且提高了系统的识别率．     

基于改进C_0复杂度和MFCC相似度的端点检测

为了提高语音端点检测的准确率,提出一种基于改进C0复杂度和MFCC相似度相结合的端点检测算法。首先,计算每一帧语音信号的C0复杂度以及MFCC相似度。然后,结合C0复杂度与MFCC相似度作为新的特征参数,设置阈值进行端点检测。对信噪比在-15~15 d B范围内的含噪语音进行端点检测,使用Matlab软件进行仿真实验。实验结果表明,该方法相对于单独的两种方法提高了检测率,且稳定性更强。     

基于DTW的轮椅命令字识别系统研究

采用一种双门限的端点检测算法精确地检测出了语音端点;对线性预测倒谱系数LPCC和Mel频率倒谱系数MFCC的性能进行了对比分析;以MFCC为特征参数,实现了基于动态时间归整算法DTW的轮椅命令字识别系统,识别效果达到90%以上.DTW的高效算法降低了算法的执行时间,优化了系统性能.     

基于MEFF倒谱距离与对数能量融合的语音端点检测方法

为提高低信噪比环境下语音端点检测算法性能不高的问题,提出将MFCC倒谱距离与对数能量结合进行端点检测.首先,对语音计算对数能量,然后计算改进的倒谱距离,将MFCC倒谱距离与对数能量融合,获得了一种新的语音参数,该参数能有效地提高低信噪比情况下语音与噪声的区别,对参数进行顺利滤波用于语音端点检测,采用自动更新的双阈值进行语音端判别.仿真实验表明,该算法具有较好的适用不同噪声,在低信噪比下依然能获得比较理想的端点检测效果.     

基于MFCC倒谱距离的语音端点检测方法

在一个语音信号处理系统中,端点检测是对语音预处理阶段最重要的环节,好的检测效果可提高后续语音处理的效率。文章结合语音信号特性,采用根据人耳听觉机理Mel频率倒谱系数(Mel Frequency Coefficient,MFCC)对带噪语音进行端点检测,通过仿真实验的方式证明其可行性。     

基于DSP实现语音端点检测

介绍了一种以DSP芯片为核心的语音端点检测模块，用于有线／无线自动转接设备。所采用的语音端点检测算法应用多个语音特征参量进行联合检测，达到了比较满意的端点检测效果。该模块应用于系统中能够实现通话方语音对通话过程的自动控制。     

一种基于检测元音的孤立词端点检测算法

提出了基于检测元音的端点检测算法。首先检测到语音中的元音的端点。然后利用元音的端点作为参考端点检测出语音真实的端点。将新方法应用在T146数据包在NoiseX-92的5种噪声下的端点检测和识别实验。并和基于能量的端点检测算法比较。2种不同的实验表明，提出的基于检测元音的孤立词端点检测算法可以在不同信噪比下提高端点检测的准确率，并在低信噪比的环境下能明显提高语音识别系统的识别率。     

非平稳强噪声环境中的音频信号端点检测系统

为提高音频信号端点识别能力,设计一种非平稳强噪声环境中的音频信号端点检测系统。构建音频信号端点检测硬件单元,利用预处理单元对音频信号进行预加重、分帧以及加窗处理后,端点检测单元在提取处理音频信号的MFCC倒谱距离特征、频带方差特征的基础上,依据动态阈值估计策略确定恰当阈值;通过双特征参数双门限法来实现对音频信号起止点的确定以及语音帧和非语音帧的分离;利用包络确定延时单元,防止噪声段被错误识别为语音段,避免出现拖尾太长问题。实验结果表明,所设计系统可实现非平稳强噪声环境音频信号端点检测,检测误差满足设定要求。     

SOM-LSTM递归神经网络语音端点检测系统

语音端点检测是语音信号处理的一个重要环节,传统的语音端点检测算法往往是基于短时能量以及过零率等实现,在低信噪比的环境下,检测算法的准确度较低。因此,提出了一种基于自组织映射(SOM)神经网络和长短时记忆(LSTM)递归神经网络相结合的端点检测算法。该算法通过检测语音信号在每个时间节点上的特征属性利用SOM神经网络进行聚类,并根据每个时间节点的语音状态对聚类结果进行调整,构造能够判别语音状态和噪声状态的样本作为LSTM递归神经网络的输入,利用LSTM递归神经网络实现端点检测的目的。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.