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基于DSP的混沌语音加密解密系统 被引量:4
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作者 葛秀梅 仲伟波 +1 位作者 李忠梅 范东升 《实验室研究与探索》 CAS 北大核心 2014年第9期137-140,共4页
语音的数据安全是网络语音通信的重要问题之一,混沌序列由于具有类随机性常被用作加密密钥。为避免混沌流加密带来的安全风险,以TI 5509A DSP为核心设计并实现了一个混沌语音加、解密系统,通过Henon映射和改进的Logistic映射相结合生成... 语音的数据安全是网络语音通信的重要问题之一,混沌序列由于具有类随机性常被用作加密密钥。为避免混沌流加密带来的安全风险,以TI 5509A DSP为核心设计并实现了一个混沌语音加、解密系统,通过Henon映射和改进的Logistic映射相结合生成具有混沌特性的数据,再通过非线性置换生成用于IDEA加、解密的密钥,实现以太网上语音加密传输。实验结果表明该方案切实可行,系统运行稳定可靠,具有一定的应用价值。 展开更多
关键词 语音加、解密 混沌序列 IDEA DSP
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端到端语音加密通信的同步信号设计 被引量:6
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作者 陈瑶瑶 郝建华 张子博 《电讯技术》 北大核心 2016年第2期195-200,共6页
在语音加密通信过程中,接收方需要通过信号同步来实现精确的解密并恢复出语音信号,而现有方法精确度低且运算量大。为了解决端到端语音加密、解密过程中的同步问题,设计了一种新的基于线性调频信号的同步信号结构。该同步信号是基于带... 在语音加密通信过程中,接收方需要通过信号同步来实现精确的解密并恢复出语音信号,而现有方法精确度低且运算量大。为了解决端到端语音加密、解密过程中的同步问题,设计了一种新的基于线性调频信号的同步信号结构。该同步信号是基于带宽经过筛选的线性调频信号产生,避免了因为添加同步信号而使带宽扩展的问题。同步信号结构由两种不同长度的线性调频信号组合而成,不同的组合形式又会产生不同的同步效果。这种结构设计大大提高了同步的精确度和减少了同步运算量。理论和实验证明:该方法可以实现对接收信号帧起始位置进行精确地定位;不会展宽和影响语音信号的频谱;可以透过语音编解码器传输;具有一定的抗噪声性能;运算量比原始结构的同步信号大大减少。 展开更多
关键词 保密通信 语音加解密 同步信号结构 端到端 线性调频信号
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视觉和语音加工难度对汉语识字困难儿童形音特征捆绑的影响 被引量:3
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作者 钟姝 刘翔平 +4 位作者 李开强 齐婷婷 张晨晨 李燕 刘晓东 《中国特殊教育》 CSSCI 北大核心 2011年第7期60-63,共4页
研究选取汉语识字困难儿童与普通儿童各28名,通过三种图形和语音信息不同加工难度条件,考察不同视觉和语音加工难度对汉语识字困难儿童形音特征捆绑成绩的影响。实验结果显示:(1)在视觉-语音信息加工难度低的时候,汉语识字困难儿童形音... 研究选取汉语识字困难儿童与普通儿童各28名,通过三种图形和语音信息不同加工难度条件,考察不同视觉和语音加工难度对汉语识字困难儿童形音特征捆绑成绩的影响。实验结果显示:(1)在视觉-语音信息加工难度低的时候,汉语识字困难儿童形音特征捆绑正确率显著低于普通儿童,说明其形音特征捆绑落后于普通儿童。(2)在视觉信息加工难度增加时,汉语识字困难儿童形音特征捆绑成绩无显著变化;在语音信息加工难度增加时,汉语识字困难儿童形音特征捆绑成绩出现显著下降,说明视觉信息加工难度对其形音特征捆绑成绩无影响,语音信息加工引起其形音特征捆绑成绩的变化。 展开更多
关键词 汉语识字困难儿童 视觉 语音加 工形音特征捆绑
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基于Matlab的语音信号预处理技术研究 被引量:4
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作者 刘琦 尹国祥 《电子技术与软件工程》 2014年第1期62-63,共2页
语音信号的预处理技术是语音信号进行计算机处理的必经环节。本文主要对语音信号预处理步骤、其中的关键技术进行阐述,并用Matlab进行仿真实验。本文的研究对于语音信号处理的研究人员具有一定借鉴意义。
关键词 语音信号采集 语音信号分帧语音 信号预 语音信号
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Canadian English and its phonetic features 被引量:1
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作者 丁林棚 朱红梅 《Sino-US English Teaching》 2008年第1期50-55,共6页
British English and American English are regarded as the two major varieties of English in the world, and Canadian English is often treated as a variation of American English. The paper aims to identify the major phon... British English and American English are regarded as the two major varieties of English in the world, and Canadian English is often treated as a variation of American English. The paper aims to identify the major phonetic features of Canadian English by addressing its differences from British and American English based on a historical, demographical, and regional and dialectal analysis. Canadian English is a cultural phenomenon that has evolved on the basis of British English and under the heavy influence of American English. As a distinctive variety of English, Canadian English possesses its phonetic uniqueness. And in the context of globalization, Canadian English will remain subject to Americanization. 展开更多
关键词 Canadian English Canadian pronunciation English variety AMERICANIZATION phonetic differences
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Candidate Expansion Algorithm Based on WeightedSyllable Confusion Matrix for Mandarin LVCSR 被引量:2
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作者 常凤香 李宝祥 +1 位作者 刘刚 郭军 《China Communications》 SCIE CSCD 2013年第7期104-112,共9页
The inclusion of more potentially correct words in the candidate sets is important to improve the accuracy of Large Vocabulary Continuous Speech Recognition (LVCSR). A candidate expansion algorithm based on the Weig... The inclusion of more potentially correct words in the candidate sets is important to improve the accuracy of Large Vocabulary Continuous Speech Recognition (LVCSR). A candidate expansion algorithm based on the Weighted Syllable Confusion Matrix (WSCM) is proposed. First, WSCM is derived from a confusion network. Then, the reeognised candidates in the confusion network is used to conjeeture the most likely correct words based on WSCM, after which, the conjectured words are combined with the recognised candidates to produce an expanded candidate set. Finally, a combined model having mutual information and a trigram language model is used to rerank the candidates. The experiments on Mandarin film data show that an improvement of 9.57% in the character correction rate is obtained over the initial recognition performance on those light erroneous utterances. 展开更多
关键词 speech recognition candidate expansion confusion matrix
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STUDY ON PHASE PERCEPTION IN SPEECH 被引量:6
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作者 TongMing BianZhengzhong +2 位作者 LiXiaohui DaiQijun ChenYanpu 《Journal of Electronics(China)》 2003年第5期387-392,共6页
The perceptual effect of the phase information in speech has been studied by auditorysubjective tests. On the condition that the phase spectrum in speech is changed while amplitudespectrum is unchanged, the tests show... The perceptual effect of the phase information in speech has been studied by auditorysubjective tests. On the condition that the phase spectrum in speech is changed while amplitudespectrum is unchanged, the tests show that: (1) If the envelop of the reconstructed speech signalis unchanged, there is indistinctive auditory perception between the original speech and thereconstructed speech; (2) The auditory perception effect of the reconstructed speech mainly lieson the amplitude of the derivative of the additive phase; (3) td is the maximum relative time shiftbetween different frequency components of the reconstructed speech signal. The speech qualityis excellent while td <10ms; good while 10ms< td <20ms; common while 20ms< td <35ms, andpoor while td >35ms. 展开更多
关键词 Speech signal Auditory perception Phase spectrum Additive phase
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