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浅析如何降低出书成本
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作者 高飞 《出版广角》 北大核心 2012年第4期66-67,共2页
降低出书成本并不是想象的那么难,不需要增加设备、提升技术、资金等"硬件"投入,只需从"软件"上稍下工夫,一切就尽在掌握之中。
关键词 出书成本 印制数量 制作工艺 纸张材料
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QIM digital watermarkingbased on LDPC code and messagepassingunder scalingattacks
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作者 崔鑫 颜斌 +1 位作者 贾霞 王亚菲 《Journal of Measurement Science and Instrumentation》 CAS 2014年第1期37-40,共4页
Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronizati... Watermarking system based on quantization index modulation (QIM) is increasingly popular in high payload applications,but it is inherently fragile against amplitude scaling attacks.In order to resist desynchronization attacks of QIM digital watermarking,a low density parity check (LDPC) code-aided QIM watermarking algorithm is proposed,and the performance of QIM watermarking system can be improved by incorporating LDPC code with message passing estimation/detection framework.Using the theory of iterative estimation and decoding,the watermark signal is decoded by the proposed algorithm through iterative estimation of amplitude scaling parameters and decoding of watermark.The performance of the proposed algorithm is closer to the dirty paper Shannon limit than that of repetition code aided algorithm when the algorithm is attacked by the additive white Gaussian noise.For constant amplitude scaling attacks,the proposed algorithm can obtain the accurate estimation of amplitude scaling parameters.The simulation result shows that the algorithm can obtain similar performance compared to the algorithm without desynchronization. 展开更多
关键词 digital watermarking quantization index modulation (QIM) message passing algorithm based on factor graph low density parity check (LDPC) code amplitude scaling attack
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第五套人民币的冠字
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作者 蒋世才 《新疆钱币》 2004年第1期39-39,41,共2页
人民币都是一票一号,互不重复(除再版的1、2、5分外)。第五套人民币的编号,由两部分组成。置于最前面的是两个汉语拼音字母,故称为冠字。冠字之后,是八位或九位阿拉伯数码,从00000001连续递增到100000000,共1亿个号,称其为顺序... 人民币都是一票一号,互不重复(除再版的1、2、5分外)。第五套人民币的编号,由两部分组成。置于最前面的是两个汉语拼音字母,故称为冠字。冠字之后,是八位或九位阿拉伯数码,从00000001连续递增到100000000,共1亿个号,称其为顺序号或流水号。 展开更多
关键词 人民币 冠字 防伪功能 印制数量
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