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分析滤波器；线性预测；窄带语音水印；通带激励替代；能量规范化；谱包络成形；合成滤波器 1

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航空移动通信——窄带至宽带的演进

张军

《工程（英文）》 2021年第7卷第4期页码 431-434 doi: 10.1016/j.eng.2021.02.002

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一种基于子带激励替换的窄带语音水印算法 Article

Wei LIU, Ai-qun HU

《信息与电子工程前沿（英文）》 2017年第18卷第5期页码 627-643 doi: 10.1631/FITEE.1601503

摘要：本文建议了一种新的窄带语音水印算法，该算法将部分语音信号替换为一个经过幅度调节和频谱成形的隐蔽信号。文中从理论上证明了若仅对一小部分载体语音作修改，则不但可以建立一个用于隐蔽通信的理想信道模型，而且还能确保隐藏信号的不可感知性和带水印信号的可懂度。在此基础上，文中建议了一个实际的系统模型。在嵌入器中，使用了能量规范化准则，使得通带水印信号的能量与原始通带语音激励信号的能量相等，然后使用合成滤波器来对该水印信号进行频谱成形。在提取器中，先用带通滤波器去除带外信号，然后用分析滤波器对失真进行补偿。实验结果显示，本文建议算法的数据速率可达400 bits/s，具有更佳的带宽效率，且有良好的不可感知性。此外，该算法对实际应用中的各种攻击也是顽健的。

关键词：分析滤波器；线性预测；窄带语音水印；通带激励替代；能量规范化；谱包络成形；合成滤波器

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Analytical method of capsizing probability in the time domain for ships in the random beam seas

LIU Liqin, TANG Yougang, LI Hongxia

《结构与土木工程前沿（英文）》 2007年第1卷第3期页码 361-366 doi: 10.1007/s11709-007-0048-5

摘要： The methods for constructing safe basins of ships and predicting their survival probability in random waves were studied. The nonlinear differential equation of the rolling motion of ships in random beam seas was established considering nonlinear damping, nonlinear restoring moment, and random waves. The random rolling differential equation was solved in the time domain by applying the harmonic acceleration method and by synthetically considering the instantaneous state of ships and the narrowband wave energy spectrum. The numerical simulation of random capsizing course was brought forward, the safe basins were constructed for safe navigation, and the survival probabilities of ships were calculated. As an example, the safe basins on the rolling initial value plane were constructed for a 30.27-meter-long fishing vessel according to different initial conditions and random wave parameters. The survival probabilities of the fishing vessel under different significant wave heights were predicted. Thus, the survival probabilities of ships in random seas can be predicted quantitatively by the proposed method.

关键词： different survival probability different significant nonlinear differential narrowband