一种基于小波域图像纹理特征的数字水印技术

提出一种基于小波域图像纹理特征的彩色图像盲水印算法。该算法根据。图像小波变换后小波系数的特点选择视觉重要系数，量化嵌入二值水印序列。利用人类视觉系统的纹理掩蔽特性和照度掩蔽特性自适应调整量化间距，以保证水印的透明性。算法实现了水印的盲检测。仿真实验的结果表明，算法对各种常用的水印攻击方法具有较好的鲁棒性。     

基于小波域的水印最佳嵌入位置的研究

本文通过分析小波变换的系数分布特点,结合人眼视觉特性和带载图像抗攻击能力,论证了小波变换第二层的代表水平细节的HL2和代表垂直细节的LH2N水印嵌入的相对最佳嵌入位置。实验结果表明,在此位置嵌入水印,可以保证水印的隐蔽性和稳健性。     

自适应的混合域音频水印新算法

本文结合小波包变换和离散余弦变换，提出了一种基于听觉模型的混合域自适应音频盲水印算法，在不引入听觉失真的前提下，实现了自适应的水印嵌入。算法首先对音频信号进行小波包分解，使得分解后的子带更接近人耳临界频带。其次对每个子带的小波包系数进行离散余弦变换，计算出子带掩蔽阈值。根据子带掩蔽阈值自适应的选取噪声敏感度小的音频段作为水印嵌入段，选取功率值低于掩蔽阈值的频域系数作为水印嵌入位置，同时采用噪声掩蔽比调整水印嵌入强度。二值水印图像通过量化索引调制的方法嵌入到音频信号的中低频系数中，提取水印时不需要原始音频载体。本算法在水印容量、不可感知性和鲁棒性之间达到了很好的平衡，水印容量在576.7bps到689.5bps之间，算法对添加噪声、重新量化、重新采样、低通滤波和MP3压缩均具有很好的鲁棒性。      

基于HVS的小波域图像易损水印

基于小波变换,结合量化调制过程,论文提出了一种易损水印算法。该算法具有构造分层水印,便于实现水印的多分辨率嵌入;结合视觉特性量化调制,尽可能减小视觉失真;结合图像融合技术的多分辨率检测,使检测结果更准确;以技抵抗一定程度的JPEG有损压缩等特点。实验表明,嵌入的水印在易损性和鲁棒性上达到了较好的统一,能够抵抗一定程度的压缩而不影响篡改检测的精确性。     

用于音乐作品版权保护的数字音频水印算法

提出了一种用于音乐作品版权保护的数字音频水印嵌入算法，该算法首先将视觉可辨的二值水印图像降维成一维水印序列并进行随机置乱，再从原始数字音频信号中随机选取采样数据并进行快速傅立叶变换(FFT)，最后结合人类听觉系统(HAS)掩蔽特性选取绝对值较大的FFT系数嵌入水印信息。仿真实验表明：该数字音频水印嵌入算法不仅具有较好的透明性，而且对诸如叠加噪声、有损压缩、低通滤波、重新采样、重新量化等攻击均具有较好的鲁棒性。     

基于图像小波变换低频系数的数字水印算法

提出一种基于小波变换且具有图像自适应性的数字水印算法.通过小波变换将图像分解成不同空间与频率的系数,这些系数之间存在一种树结构关系,利用树结构关系对最低频系数进行分类,对不同类采用不同的嵌入对策,将水印信号嵌入在最低层逼近系数中,而现有基于小波变换的算法将水印嵌入在各个方向的中频或高频系数中.实验结果表明,该算法具有不可见性,对于通常的图像失真具有较好的鲁棒性,说明最低频成分并不是水印的禁区.     

基于多规则小波变换的视频水印加密算法研究

通过对视频嵌入水印的安全性和鲁棒性的分析,采用了一种基于多规则小波变换的视频水印嵌入与提取算法.该算法首先对水印图像进行置乱加密增强其安全性,其次对视频帧和水印图像分别进行多层小波变换,最后根据不同的小波系数进行多规则水印嵌入.算法不仅充分利用了小波变换的多分辨特性,而且兼顾了水印的不可感知性和视频帧的鲁棒性.实验结果表明,该算法对高斯噪声、几何失真和压缩等具有良好的安全性和鲁棒性.     

一种基于HVS的DCT域稳健视频水印算法

结合人类视觉系统特性及离散余弦变换理论,提出了一种基于原始视频的稳健性盲水印算法。该算法将置乱后的二值图像水印嵌入到原始视频帧绿色分量的离散余弦变换低频系数中,根据视频内容自适应地选择嵌入深度,较好地实现了水印在宿主视频中的嵌入及盲提取。实验结果表明,该视频水印算法在保证不可知性的同时对诸如Gaussian、帧剪切、Salt等攻击均具有良好的稳健性,即使在攻击强度较大的情况下仍然能够提取出较清晰的水印信号。     

一种基于图像处理的信息隐蔽算法

图像处理中的数字水印技术是通过特定算法将标志信息嵌入到多媒体载体中，可用于隐蔽通信及信息对抗等领域。提出了一种基于小波变换的数字水印算法，该算法结合人类视觉系统（HVS）特性。根据不同子带噪声容量上限选取适当的子带，对所选系数做一定筛选，将水印嵌入到第三阶小波变换子带系数的部分高频系数上，同时保证水印的不可见性和鲁棒性，并通过实验证明，利用该算法嵌入的水印对于锐化、剪切及JPEG／JPEG2000压缩等攻击都有较强的鲁棒性。     

基于离散小波变换和混沌加密的图像水印算法

文中提出了一种基于离散小波变换和混沌加密的数字水印新算法,采用二维混沌变换对水印图像加密;对载体图像进行多分辨离散小波变换,应用小波系数判断载体图像的纹理复创杂程度后,依据人眼的视觉系统（HVS）特性,将水印信号嵌入到图像的低频部分,对图像的不同分解层分别选取不同的纹理阈值和水印嵌入强度,将数字水印嵌入到相同分辨层的原始图像中,提高了水印算法的鲁棒性.在检测和提取水印时,通过水印相似度（NC）和峰值信噪比（PNSR）评价水印质量,实验结果表明提出的算法可以抵抗剪裁、JPEG压缩、滤波等几何攻击,算法简单,计算复杂度小,兼顾了水印的不可见性和鲁棒性.     

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.