数字水印技术在多媒体信息安全中的应用

随着多媒体技术和网络技术的广泛应用，对图像、音频、视频等多媒体内容的保护成为迫切需要解决的问题。数字水印技术作为版权保护和安全认证的有力工具，已引起人们广泛的关注。简要介绍了数字水印技术的原理及基于该技术提出的版权认证方案在WWW上的应用。     

数字水印技术在电力信息安全保障中的应用

针对电力系统中亟待解决的信息安全问题,数字水印技术的应用有助于提高信息安全保障。从数字水印系统基本模型与特点等方面讨论了数字水印技术的基本原理。根据多媒体载体形式不同,分析了不同类型的数字水印技术。基于数字水印技术在电力信息安全保障中的不同应用方面,从隐蔽通信、内容认证与版权保护等应用方面重点讨论了其实际使用情况。最后,针对数字水印技术的发展趋势进行了展望。     

数字水印技术的研究

随着多媒体技术和网络技术的飞速发展和广泛应用，对图像、音频、视频等多媒体内容的保护成为迫切需要的问题。数字水印技术作为版权保护和安全认证的有力工具，已得到了广泛的关注和发展。本文简要介绍了数字水印技术的基本原理、特征和典型算法。     

数字版权管理的关键技术

针对当前基于数字水印或者密码学的数字版权管理技术存在的缺陷,介绍了在多媒体环境下实现数字版权管理涉及到的一些关键技术,包括适合多媒体的加密认证技术、能抵抗几何攻击的数字水印技术、基于脆弱水印的图像/视频/音频认证技术和基于统计分析的被动式图像篡改分析和检测方法等,并分析了这些技术的用途及应达到的技术要求。未来的数字版权保护平台应该是综合利用这些先进技术,实现对数字媒体内容的全方位保护。     

数字水印技术分析及其在电视领域的应用

数字水印是多媒体版权保护的一种有效技术手段.介绍数字水印技术的基本原理,阐述了视频数字水印应具有的特点,讨论压缩域视频数字水印算法.在此基础上,提出数字水印在电视领域的应用方案.该技术为电视版权管理的有效实施具有一定的借鉴作用.     

数字水印技术及其在电子商务中的应用

随着互联网和电子商务的迅猛发展，诸如电子商务中的网页保护、电子票据防伪及多媒体数字产品的版权保护等信息安全问题日益突出。数字水印技术作为解决此类问题的有效办法引起越来越多的相关研究人员的兴趣。本文介绍了数字水印技术以及主要的数字水印算法，给出了一个仿真实例，并讨论了其在电子商务领域中的应用。     

关于数字图像的水印技术

随着多媒体技术和网络技术的广泛应用，对图像、音频、视频等多媒体内容的保护成为迫切需要解决的问题。数字水印技术是目前信息安全领域的一个新方向，是一种可以在开放的网络环境下保护版权和认证来源及完整性的新技术。本文在介绍了数字水印的基本要求的同时，给出了系统的框架，以及数字水印的原理和目前主要的应用领域，并探讨了数字水印的特点及其所受到的各种攻击方式，给出了典型算法，研究水印的嵌入、提取和检测并给出了模型，最后给出数字水印的研究方向。     

数字水印技术研究

作为数字多媒体产品的版权保护和数据完整性验证的技术,数字水印技术近年来已成为研究热点。介绍了数字水印技术的基本概念、特性和分类,并对数字水印系统模型和典型数字水印算法进行了深入分析,最后给出了数字水印技术的应用和总结。     

试论数字图像水印算法的研究与实现

网络时代的到来及数字多媒体技术的飞速发展与广泛应用,极大地便利了人们的日常生活。与此同时,有关数字产品版权保护的呼声也越来越高。作为一种现代化数据版权保护与认证技术,数字图像水印技术成为当前学术领域的研究焦点,具有十分重要的现实意义和应用前景。文章结合数字水印技术的特点,探讨了数字图像水印的几种重要算法,以供参考。     

无线内容自适应技术研究

介绍和分析内容自适应相关技术,重点讨论自适应策略及其分类、网络监控方法以及构架设计方面的内容.在此基础上,研究内容自适应技术在无线领域应用的问题,并以移动多媒体传输为例研究其网络局限性,并讨论适应移动多媒体内容分发的网络感知策略.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks