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基于2^(n)-1长m序列的FHT运算及FPGA实现
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作者 张庆业 王力男 周微 《无线互联科技》 2024年第4期27-29,共3页
在地面4G/5G移动通信中辅同步信号(Secondary Synchronization Signal,SSS)都由长为31和127的小m序列组成,在求最大相关值运算中通常都采用快速哈达码变换(Fast Hadamard Transform,FHT)来减少计算量、降低运算资源的使用,但是对于任意... 在地面4G/5G移动通信中辅同步信号(Secondary Synchronization Signal,SSS)都由长为31和127的小m序列组成,在求最大相关值运算中通常都采用快速哈达码变换(Fast Hadamard Transform,FHT)来减少计算量、降低运算资源的使用,但是对于任意长序列的FHT推导没有扩展描述。文章针对基于2^(n)-1任意长度的小m序列到FHT运算的行列变换过程给出了完整的矩阵推导,并利用长为3的小m序列进行仿真验证结论的正确性,最后以5G标准中长度为127的SSS序列完成FHT的FPGA实现。 展开更多
关键词 辅同步信号 快速哈达码变换 M序列 FPGA
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基于CEEMDAN-HT的永磁同步电机匝间短路振动信号故障特征提取研究
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作者 夏焰坤 李欣洋 +1 位作者 任俊杰 寇坚强 《振动与冲击》 EI CSCD 北大核心 2024年第5期72-81,共10页
由于长时间处于高负荷运行状态,永磁同步电机(permanent magnet synchronous motor, PMSM)定子绕组线圈匝与匝之间的绝缘性能容易降低,导致出现匝间短路,此时电机的振动强度会发生改变。针对此现象,提出将自适应噪声完备经验模态分解(co... 由于长时间处于高负荷运行状态,永磁同步电机(permanent magnet synchronous motor, PMSM)定子绕组线圈匝与匝之间的绝缘性能容易降低,导致出现匝间短路,此时电机的振动强度会发生改变。针对此现象,提出将自适应噪声完备经验模态分解(complete ensemble empirical mode decomposition with adaptive noise, CEEMDAN)与希尔伯特变换(Hilbert transform, HT)结合,构成一种CEEMDAN-HT非线性信号分析方法,并将其应用于提取振动信号故障特征。首先,利用CEEMDAN算法分解振动信号,得到一系列本征模态函数(intrinsic mode function, IMF),并将主元分析中的方差贡献率用于识别包含故障特征信息的IMF。其次,使用HT对方差贡献率较高的IMF进行分析,并以三维联合时频图呈现时间、瞬时频率与幅值,得到了主要故障特征。最后,使用ANSYS有限元软件建立了电机短路故障模型,并搭建了短路故障试验平台,通过对比有限元仿真结果与试验结果,对提出的方法进行了有效性和准确性验证。 展开更多
关键词 永磁同步电机(permanent magnet synchronous motor PMSM) 振动信号 自适应噪声完备经验模态分解(complete ensemble empirical mode decomposition with adaptive noise CEEMDAN) 特征提取 希尔伯特变换(Hilbert transform ht)
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基于MEEMD与HT的谐波检测方法 被引量:3
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作者 周军 李永祥 任佳鹏 《电力系统及其自动化学报》 CSCD 北大核心 2023年第6期73-82,共10页
为解决采用希尔伯特-黄变换进行谐波分析对信号进行分解时出现的模态混叠、端点效应、抗噪能力弱及虚假分量等问题,提出一种基于改进型总体平均经验模态分解和改进的自适应波形匹配延拓结合希尔伯特变换的谐波检测新方法。首先,采用改... 为解决采用希尔伯特-黄变换进行谐波分析对信号进行分解时出现的模态混叠、端点效应、抗噪能力弱及虚假分量等问题,提出一种基于改进型总体平均经验模态分解和改进的自适应波形匹配延拓结合希尔伯特变换的谐波检测新方法。首先,采用改进型总体平均经验模态分解算法和改进的自适应波形匹配延拓方法对谐波信号进行分解,获得一系列固有模态函数,再对各个固有模态函数进行希尔伯特变换,从而得到各次谐波的瞬时幅值和瞬时频率。采用经验模态分解、总体平均经验模态分解、完全经验模态分解算法和文中所提方法分别与希尔伯特变换结合进行谐波分析,仿真结果表明,所提方法能有效抑制模态混叠和端点效应,其受参数影响较小,自适应性较强,产生较少的虚假分量,且在强噪声下仍然具有很高的谐波检测精度。 展开更多
关键词 谐波检测 模态混叠 端点效应 去噪 希尔伯特变换
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A novel image encryption scheme based on Keplers third law and random Hadamard transform 被引量:3
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作者 罗玉玲 周戎龙 +2 位作者 刘俊秀 丘森辉 曹弋 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期146-159,共14页
In this paper, a novel image encryption scheme based on Keplers third law and random Hadamard transform is proposed to ensure the security of a digital image. First, a set of Kepler periodic sequences is generated to ... In this paper, a novel image encryption scheme based on Keplers third law and random Hadamard transform is proposed to ensure the security of a digital image. First, a set of Kepler periodic sequences is generated to permutate image data, which is characteristic of the plain-image and the Keplers third law. Then, a random Hadamard matrix is constructed by combining the standard Hadamard matrix with the hyper-Chen chaotic system, which is used to further scramble the image coefficients when the image is transformed through random Hadamard transform. In the end, the permuted image presents interweaving diffusion based on two special matrices, which are constructed by Kepler periodic sequence and chaos system. The experimental results and performance analysis show that the proposed encrypted scheme is highly sensitive to the plain-image and external keys, and has a high security and speed, which are very suitable for secure real-time communication of image data. 展开更多
关键词 Kepler&#39s third law random hadamard transform interweaving diffusion security
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Blind reconstruction of convolutional code based on segmented Walsh-Hadamard transform 被引量:8
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作者 Fenghua Wang Hui Xie Zhitao Huang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第5期748-754,共7页
Walsh-Hadamard transform (WriT) can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enorm... Walsh-Hadamard transform (WriT) can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enormous computer memory which limits the application of WriT. In order to solve this problem, a method based on segmented WriT is proposed in this paper. The coefficient vector of high dimension is reshaped and two vectors of lower dimension are obtained. Then the WriT is operated and the requirement for computer memory is much reduced. The code rate and the constraint length of convolutional code are detected from the Walsh spectrum. And the check vector is recovered from the peak position. The validity of the method is verified by the simulation result, and the performance is proved to be optimal. 展开更多
关键词 convolutional code blind reconstruction Walsh-hadamard transform (WriT) tinear error equation.
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Walsh Hadamard Transform Based Transceiver Design for SC-FDMA with Discrete Wavelet Transform 被引量:2
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作者 Arsla Khan Amna Arif +1 位作者 Tabassum Nawaz Sobia Baig 《China Communications》 SCIE CSCD 2017年第5期193-206,共14页
This article proposes a new transceiver design for Single carrier frequency division multiple access(SCFDMA)system based on discrete wavelet transform(DWT). SCFDMA offers almost same structure as Orthogonal frequency ... This article proposes a new transceiver design for Single carrier frequency division multiple access(SCFDMA)system based on discrete wavelet transform(DWT). SCFDMA offers almost same structure as Orthogonal frequency division multiple access(OFDMA)with extra advantage of low Peak to Average Power Ratio(PAPR). Moreover,this article also suggests the application of Walsh Hadamard transform(WHT)for linear precoding(LP)to improve the PAPR performance of the system. Supremacy of the proposed transceiver over conventional Fast Fourier transform(FFT)based SCFDMA is shown through simulated results in terms of PAPR,spectral efficiency(SE)and bit error rate(BER). 展开更多
关键词 离散小波变换 收发器 哈达玛变换 正交频分多址接入 设计 hadamard变换 沃尔什 快速傅里叶变换
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Implementing Classical Hadamard Transform Algorithm by Continuous Variable Cluster State 被引量:1
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作者 王宇 苏琦 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期19-23,共5页
Measurement-based one-way quantum computation, which uses cluster states as resources, provides an efficient model to perforrn computation. However, few of the continuous variable (CV) quantum algorithms and classic... Measurement-based one-way quantum computation, which uses cluster states as resources, provides an efficient model to perforrn computation. However, few of the continuous variable (CV) quantum algorithms and classical algorithms based on one-way quantum computation were proposed. In this work, we propose a method to implement the classical Hadamard transform algorithm utilizing the CV cluster state. Compared with classical computation, only half operations are required when it is operated in the one-way CV quantum computer. As an example, we present a concrete scheme of four-mode classical Hadamard transform algorithm with a four-partite CV cluster state. This method connects the quantum computer and the classical algorithms, which shows the feasibility of running classical algorithms in a quantum computer efficiently. 展开更多
关键词 Implementing Classical hadamard transform Algorithm by Continuous Variable Cluster State
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A generalized Hadamard transformation from new entangled state
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作者 徐兴磊 徐世民 +2 位作者 张运海 李洪奇 王继锁 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期105-109,共5页
A new entangled state |η 0) is proposed by the technique of integral within an ordered product. A generalized Hadamaxd transformation is derived by virtue of η; θ), which plays a role of Hadamard transformation ... A new entangled state |η 0) is proposed by the technique of integral within an ordered product. A generalized Hadamaxd transformation is derived by virtue of η; θ), which plays a role of Hadamard transformation for (a1 sinθ - a2 cosθ) and (a1 cosθ + a2 sin θ). 展开更多
关键词 generalized hadamard transformation entangled state technique of integral within an ordered product
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Studies on Hadamard Transform Fluorimetry
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作者 Chen Guanquan, Yang Xiaohong, Li Jianjun and Hu Jiming (Department of Analysis-Measurement Science, Wuhan University, Wuhan) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1992年第1期27-28,共2页
Hadamard transform spectroscopy has been investigated since the later 1960’s and early 1970’s. It was demonstrated that the application of Hadamard transform technique to spectroscopy can facilitate multichannel det... Hadamard transform spectroscopy has been investigated since the later 1960’s and early 1970’s. It was demonstrated that the application of Hadamard transform technique to spectroscopy can facilitate multichannel detection of weak signal. It can be appplied not only to component analysis, but to image analysis. Now, it has been widely used in infrared spectrometry, Raman spectrometry and photothermal deflection analysis. But its application to molecular fluorimetry has not been reported up to now. 展开更多
关键词 hadamard transform New Fluorophotometer
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A Watermarking Algorithm Based on Wavelet and Hadamard Transform for Color Image
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作者 Hongshou Yan Weimin Yang 《Journal of Software Engineering and Applications》 2013年第3期58-61,共4页
Digital image watermarking is a useful solution to the problem of information security, copyright and network security. In this paper, we propose a watermarking algorithm for color image based HT and DWT. A binary ima... Digital image watermarking is a useful solution to the problem of information security, copyright and network security. In this paper, we propose a watermarking algorithm for color image based HT and DWT. A binary image as watermark is embedded into green component or blue component of color image. The algorithm can satisfy the transparence and robustness of the watermarking system very well. The experiment based on this algorithm demonstrates that the watermarking is robust to the common signal processing techniques including JPEG compressing, adding noise, low pass filter, and mosaic. 展开更多
关键词 Digital Watermarking hadamard transform(ht) Discrete WAVELET transform(DWT) Color Image COPYRIGht Protection
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Joint Non-Orthogonal Multiple Access (NOMA) & Walsh-Hadamard Transform: Enhancing the Receiver Performance 被引量:2
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作者 Muhammad Rehan Usman Arsla Khan +1 位作者 Muhammad Arslan Usman Soo young Shin 《China Communications》 SCIE CSCD 2018年第9期160-177,共18页
Non-orthogonal multiple access(NOMA) is a new access method to achieve high performance gains in terms of capacity and throughput, so it is currently under consideration as one of the candidates for fifth generation(5... Non-orthogonal multiple access(NOMA) is a new access method to achieve high performance gains in terms of capacity and throughput, so it is currently under consideration as one of the candidates for fifth generation(5 G) technologies. NOMA utilizes power domain in order to superimpose signals of multiple users in a single transmitted signal. This creates a lot of interference at the receive side. Although the use of successive interference cancellation(SIC) technique reduces the interference, but to further improve the receiver performance, in this paper, we have proposed a joint Walsh-Hadamard transform(WHT) and NOMA approach for achieving better performance gains than the conventional NOMA. WHT is a well-known code used in communication systems and is used as an orthogonal variable spreading factor(OVSF) in communication systems. Application of WHT to NOMA results in low bit error rate(BER) and high throughput performance for both low and high channel gain users. Further, it also reduces peak to average power ratio(PAPR) of the user signal. The results are discussed in terms of comparison between the conventionalNOMA and the proposed technique, which shows that it offers high performance gains in terms of low BER at different SNR levels, reduced PAPR, high user throughput performance and better spectral efficiency. 展开更多
关键词 存取方法 接收装置 多重 直角 表演 连接 产量性能 通讯系统
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Determination of Instantaneous Frequencies of Low Plasma Waves in the Magnetosheath Using Empirical Mode Decomposition (EMD) and Hilbert Transform (HT)
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作者 Ekong Ufot Nathaniel Nyakno Jimmy George Sunday Edet Etuk 《Atmospheric and Climate Sciences》 2013年第4期576-580,共5页
The observations of in-situ spacecraft mission in the magnetosheath and a region of thermalized subsonic plasma behind the bow shock reveal a non-linear behaviour of plasma waves. The study of waves and optics in Phys... The observations of in-situ spacecraft mission in the magnetosheath and a region of thermalized subsonic plasma behind the bow shock reveal a non-linear behaviour of plasma waves. The study of waves and optics in Physics has given the understanding of the effect of many waves coming together to form a wave field or wave packet. The common aspect of such study shows that two or more waves can superimpose constructively or destructively. The sudden high magnetic field data in the magnetosheath displays such possibility of superposition of waves. In this paper, we use the empirical mode decomposition (EMD) and Hilbert transform (HT) techniques to determine the instantaneous frequencies of low frequency plasma waves in the magnetosheath. Our analysis has shown that the turbulent behavior of magnetic field in the magnetosheath within the selected period is due to superposition of waves. 展开更多
关键词 Plasma WAVES Instantaneous Frequency Empirical Mode Decomposition (EMD) HILBERT transform (ht)
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Development of HTS Transformers and a 10 kVA HTS Transformer Prototype Design
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作者 Xiao-Yuan Chen Jian-Xun Jin 《Journal of Electronic Science and Technology of China》 2008年第2期130-136,共7页
With the improvement of high temperature superconductor (HTS) practical performance, research and development concerning the applications of HTS transformers have been progressed actively worldwide. This paper provi... With the improvement of high temperature superconductor (HTS) practical performance, research and development concerning the applications of HTS transformers have been progressed actively worldwide. This paper provides a comprehensive summary on various HTS transformers, and studies the design of a single-phase 10 kVA (220V/24V) HTS transformer prototype to verify HTS for practical transformer applications. 展开更多
关键词 htS htS power transformer htS traction transformer htS windings.
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基于VMD的广义三次互相关管道泄漏定位检测
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作者 王冬梅 童影力 +1 位作者 何壮 路敬祎 《压力容器》 北大核心 2024年第2期72-80,共9页
针对天然气管道泄漏检测声波定位技术中,二次互相关时延估计算法存在较大误差的问题,提出了一种基于变分模态分解(VMD)结合广义三次互相关的时延估计算法。该方法首先利用VMD算法对两路信号进行分解并重构信号;其次,在二次互相关的基础... 针对天然气管道泄漏检测声波定位技术中,二次互相关时延估计算法存在较大误差的问题,提出了一种基于变分模态分解(VMD)结合广义三次互相关的时延估计算法。该方法首先利用VMD算法对两路信号进行分解并重构信号;其次,在二次互相关的基础上再进行一次相关,并在互相关算法的峰值检测阶段引入希尔伯特变换(HT),对峰值进行尖锐化处理,成为一种新型的广义三次互相关时延估计算法。通过对平台搭建的油气管道泄漏检测系统采集数据进行模拟试验,分析了各算法的精度。试验表明,相较于二次互相关,改进广义三次互相关时延估计算法定位平均精度有明显的提升,有着更高的精度和更好的抗噪性能,在天然气管道泄漏定位方面有着更广泛的应用前景。 展开更多
关键词 管道泄漏检测 变分模态分解 广义三次互相关 希尔伯特变换(ht)
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基于Hadamard变换和LU分解的盲水印算法 被引量:3
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作者 吴捷 马小虎 《计算机技术与发展》 2016年第2期82-86,共5页
为提高传统数字图像水印算法的安全性,解决数字水印对信号处理和几何失真比较敏感的问题,提出一种基于Hadamard变换和LU分解的盲水印嵌入算法。不同于常见的变换域数字水印技术,该方案对原始图像进行二维Hadamard变换(HT),将得到的变换... 为提高传统数字图像水印算法的安全性,解决数字水印对信号处理和几何失真比较敏感的问题,提出一种基于Hadamard变换和LU分解的盲水印嵌入算法。不同于常见的变换域数字水印技术,该方案对原始图像进行二维Hadamard变换(HT),将得到的变换图像进行8×8分块,然后对每个分块进行LU及SVD分解,从得到的对角矩阵中选择一个关键位嵌入水印。通过计算所有关键位的平均值,并比较每个关键位和平均值的大小关系,计算得到密钥,利用密钥实现了水印的盲检测。实验结果表明,提出的盲水印算法不但具有较好的保真度,对于各种攻击也具有较强的鲁棒性。 展开更多
关键词 数字水印 hadamard变换 LU分解 鲁棒性
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一种基于HT系数预测的遥感图像多分辨融合方法 被引量:2
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作者 陆立明 王润生 《遥感技术与应用》 CSCD 2001年第2期116-120,共5页
信息融合的概念自 70年代形成后 ,由于其强调应用对象结果的信息优化 ,在许多方面比传统的信息处理方法有更大的优势 ,在遥感领域得到了广泛的应用。本文在分析前人算法的基础上 ,揭示了高斯拉普拉斯金字塔 ( GLP)结构融合方法与传统的... 信息融合的概念自 70年代形成后 ,由于其强调应用对象结果的信息优化 ,在许多方面比传统的信息处理方法有更大的优势 ,在遥感领域得到了广泛的应用。本文在分析前人算法的基础上 ,揭示了高斯拉普拉斯金字塔 ( GLP)结构融合方法与传统的哈达玛变换 ( HT)之间的内在联系 ,提出了一种基于 HT系数预测的多分辨融合方法。通过实验表明 ,这一算法对于光谱差异较大的遥感图像的融合 ,在几何分辨率改善的同时可获得较好的光谱保真度。 展开更多
关键词 多分辨分析 ht变换 图像融合 高斯拉普拉斯金字塔结构 遥感图像
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基于Walsh-Hadamard变换的单像素遥感成像 被引量:15
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作者 李明飞 莫小范 +4 位作者 赵连洁 霍娟 杨然 李凯 张安宁 《物理学报》 SCIE EI CAS CSCD 北大核心 2016年第6期110-116,共7页
本文提出了基于Walsh-Hadamard变换的单像素成像方案,并从理论分析、模拟仿真和实验验证三方面分别验证了该方案的可行性.实验上实现了350—900 nm波段对距离500 m和5000 m自然目标的128×128像素成像,成像速度0.5帧/秒.研究并讨论... 本文提出了基于Walsh-Hadamard变换的单像素成像方案,并从理论分析、模拟仿真和实验验证三方面分别验证了该方案的可行性.实验上实现了350—900 nm波段对距离500 m和5000 m自然目标的128×128像素成像,成像速度0.5帧/秒.研究并讨论了单像素相机方案与计算量子成像方案的差异与共性,在此基础上分析了基于Walsh-Hadamard变换的单像素成像方案的优势与局限性.研究表明本方案同时适用于单像素相机和计算量子成像.由于单像素成像适用于应用在如红外热成像、微波成像等波段,因此在阵列探测器灵敏度或工艺达不到要求时存在优势.本文所提出的方案使得单像素成像技术向实际应用迈进了一步. 展开更多
关键词 Walsh-hadamard变换 单像素相机 计算量子成像
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用快速哈达玛变换(FHT)实现高速线性卷积 被引量:10
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作者 乔志伟 魏学业 韩焱 《电子测量与仪器学报》 CSCD 2010年第3期263-267,共5页
为了加速实现长序列的线性卷积,提出了用快速哈达玛变换(FHT)实现线性卷积的快速算法。分析了哈达玛变换的特点和快速算法的时间复杂度,设计了用FHT计算线性卷积的矩阵表达式,并推导出了哈达玛域滤波器的增益矩阵的求解公式,分析了该方... 为了加速实现长序列的线性卷积,提出了用快速哈达玛变换(FHT)实现线性卷积的快速算法。分析了哈达玛变换的特点和快速算法的时间复杂度,设计了用FHT计算线性卷积的矩阵表达式,并推导出了哈达玛域滤波器的增益矩阵的求解公式,分析了该方法的加速原理及其适用条件。理论分析和实验表明,该方法比FFT线性卷积法快了近一倍。 展开更多
关键词 线性卷积 圆周卷积 加速 哈达玛变换 沃尔什变换
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DFSMN-T:结合强语言模型Transformer的中文语音识别 被引量:9
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作者 胡章芳 蹇芳 +2 位作者 唐珊珊 明子平 姜博文 《计算机工程与应用》 CSCD 北大核心 2022年第9期187-194,共8页
自动语音识别系统由声学模型和语言模型两部分构成,但传统语言模型N-gram存在忽略词条语义相似性、参数过大等问题,限制了语音识别字符错误率的进一步降低。针对上述问题,提出一种新型的语音识别系统,以中文音节(拼音)作为中间字符,以... 自动语音识别系统由声学模型和语言模型两部分构成,但传统语言模型N-gram存在忽略词条语义相似性、参数过大等问题,限制了语音识别字符错误率的进一步降低。针对上述问题,提出一种新型的语音识别系统,以中文音节(拼音)作为中间字符,以深度前馈序列记忆神经网络DFSMN作为声学模型,执行语音转中文音节任务,进而将拼音转汉字理解成翻译任务,引入Transformer作为语言模型;同时提出一种减少Transformer计算复杂度的简易方法,在计算注意力权值时引入Hadamard矩阵进行滤波,对低于阈值的参数进行丢弃,使得模型解码速度更快。在Aishell-1、Thchs30等数据集上的实验表明,相较于DFSMN结合3-gram模型,基于DFSMN和改进Transformer的语音识别系统在最优模型上的字符错误率相对下降了3.2%,达到了11.8%的字符错误率;相较于BLSTM模型语音识别系统,其字符错误率相对下降了7.1%。 展开更多
关键词 语音识别 深度前馈序列记忆神经网络(DFSMN) transformER 中文音节 hadamard矩阵
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基于EMD和HT的旋转机械振动信号时频分析 被引量:48
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作者 胡劲松 杨世锡 +1 位作者 吴昭同 严拱标 《振动.测试与诊断》 EI CSCD 2004年第2期106-110,共5页
把一列时间序列数据通过经验模态分解 (Em pirical Mode Decomposition,简称 EMD)成本征模函数组(Intrinsic Mode Function,简称 IMF) ,然后经希尔伯特变换 (Hilbert Transform ation,简称 HT)获得频谱的信号时频分析新方法引入到旋转... 把一列时间序列数据通过经验模态分解 (Em pirical Mode Decomposition,简称 EMD)成本征模函数组(Intrinsic Mode Function,简称 IMF) ,然后经希尔伯特变换 (Hilbert Transform ation,简称 HT)获得频谱的信号时频分析新方法引入到旋转机械振动信号处理领域。介绍了该方法的理论和算法。首先 ,采用调频调幅仿真信号对该方法进行仿真验证 ;其次 ,把一实测的旋转机械油膜涡动故障振动信号进行了基于 EMD和 HT的时频分析。仿真和实测信号的分析结果说明 ,用基于 EMD和 展开更多
关键词 旋转机械 振动信号 经验模态分解 希尔伯特变换 时频分析
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