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61.
ROI-based Watermarking Scheme for JPEG 2000   总被引:1,自引:0,他引:1  
A new region of interest (ROI)-based watermarking method for JPEG 2000 is presented. The watermark is embedded into the host image based on the characteristics of the ROI to protect rights to the images. This scheme integrates the watermarking process with JPEG 2000 compression procedures. Experimental results have demonstrated that the proposed watermark technique successfully survives JPEG 2000 compression, progressive transmission, and principal attacks.  相似文献   
62.
将3组不同纤维体积分数的整体毡采用等温CVD进行沉积热解炭增密,结合CVD沉积过程中整体毡内气体传质数学模型,研究了整体毡的纤维体积分数对CVD增密过程的影响,研究结果表明:纤维体积低的整体毡沉积时增重率高;纤维体积分数高的整体毡容易获得较高密度的C/C复合材料;纤维体积分数超过35%的整体毡经过300 h的化学气相沉积,坯体的体积密度能达到1.52 g/cm~3。  相似文献   
63.
详细介绍了电话通讯技术以及安全报警技术的应用,二者如何有效地结合起来形成综合联网报警系统。分析了HT9200A和MT8870DC的电路结构,及与AT89C51的接口电路。  相似文献   
64.
A new optimization model is discussed for the design of cellular manufacturing systems. It is based on an integer programming formulation that updates some other models by eliminating redundant machine assignment and cost coefficients dependent on cell configuration. To reduce computational burdens, a simplified integer programming model and a decomposition algorithm are proposed. Several computer solutions were performed to evaluate the performance of the new model. The computational results are discussed.  相似文献   
65.
The broadband integrated services digital networks (B-ISDN) based on asynchronous transfer mode (ATM) technology can support a wide range of applications such as voice, video, still images, and data. Compression techniques increase the effective bandwidth utilization, but the bursty and asynchronous nature of the traffic can still lead to congestion in the network, and degradation of image quality and quality of service (QOS). Some of the features to provide better coding schemes for ATM networks are layered coding, resynchronization, buffering, interleaved schemes, constrained bit rate due to buffers, encapsulation with the RTP or AAL1 for clock recovery, lapped transforms, motion compensation, and optimal bit allocation for coders based on wavelet transforms. We review various techniques forimage and video coding such as transforms, motion compensation, vector quantization, and subband coding. We outline the impact of the cell loss ratio (CLR), delay and cell delay variation (CDV) on video coding: blocking effects, loss of frame synchronization, motion vectors, and vector quantization codewords. The open problems include tuning coding parameters to the available QOS provided by the network.  相似文献   
66.
The transport of video images is likely to be a major application of high-speed networks of the future. These applications are capable of utilizing the high bandwidths that will become available with the advent of B-ISDN. In this paper, we propose a new methodology (called TES) for modeling the frame bitrate stream generated by compressed video sources. The main characteristic of this method is that it can model an arbitrary marginal distribution and approximate the autocorrelation structure of the random bitrate process generated by compressed frames. We present a modeling example utilizing this method, based on data from a video coding algorithm employing a layering technique. Using the source model, we develop a simulation model of a multiplexer of video sources. We show that this model can be used to address a number of design issues that arise in this class of problem. In particular, we show that for a layered video coding algorithm, it is possible to have a gain in the number of sources multiplexed at the cost of some loss of low priority packets.  相似文献   
67.
在分析回顾现有话音编码方案基础上提出话音编码系统的五层结构模型以及“在收端利用边信息获取激励码”的概念。  相似文献   
68.
本文介绍了多路缓变信号记录仪的系统构成,研究设计了多路缓变信号记录仪的硬件电路,较详细地介绍了该系统的工作原理及软件编程要点。  相似文献   
69.
Recent advances in experimental technique make SuperDense Teleportation (SDT) possible only now, ten years after my first proposal at an ISI Torino summer conference on Quantum Computing. The effect uses remote state preparation to send more state-specifying parameters per bit than ordinary quantum teleportation (QT) can transmit. The SDT uses a maximally entangled state to teleport the relative phases of an n-dimensional state with equal amplitudes on every standard basis vector. For n greater than or equal to 3, the SDT sends more of these state-specifying parameters than QT. In the limit of large n the ratio is 2 to 1, hence the nomenclature by analogy with Super Dense Coding. Alice’s measurements and Bob’s transformations are far simpler than their corresponding operations in QT. The roles of Charles who chooses the state and Diana who deploys it are different than in QT. My discussion includes a brief review of the progress and possibilities of realization for several different experimental approaches around the world. This paper is the write-up of my remarks at the Festschrift conference for Anton Zeilinger, for many years a close collaborator in the Hampshire College NSF grant continuing our work with Mike Horne and Danny Greenberger started under Cliff Shull at MIT in the late 20th century.  相似文献   
70.
报导了一类新型的化学功能材料———UV固化光纤色标油墨。该材料由可UV固化的有机硅环氧安息香酸丙烯酸酯(SEBA)和脂环族环氧丙烯酸酯(ACEA)两种光敏预聚物为基料,以自行合成的光敏染料———分散红氨基甲酸酯丙烯酸酯(RUA)、分散蓝氨基甲酸酯丙烯酸酯(BUA)和吖啶黄氨基甲酸酯丙烯酸酯(YUA)为着色剂,加入必要的添加剂配制而成的UV固化光纤色标油墨。该色标油墨已在光纤生产中得到应用。  相似文献   
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