采用超音段韵律特征联合短时频谱的语音转换

传统的语音转换方法往往着重于语音的声道特征和基频的转换,而忽视了其他的超音段韵律特征,这导致转换后的语音目标倾向性不够明显,合成语音自然度不高,不能很好地反应说话人个性化特征。本文在短时谱包络转换的基础上,加入了基频、语速、停顿、重音等多种超音段韵律特征进行转换处理,以提高语音转换性能。其中,采用基频目标模型对基音频率建模,然后运用高斯混合模型（GMM）训练得到转换规则,而语速、停顿、重音则采用基于单高斯统计分析的最大似然估计方法训练得到转换规则。实验结果表明,在加入超音段韵律特征转换之后,系统非常明显地提高了转换语音的目标倾向性和自然度。      

结合韵律和音质参数的改进二次判别式在语音情感识别中的应用

提取可以表征唤醒维的韵律参数和表征效价维的音质参数综合用于语音情感识别是近年来此领域的一个研究方向.为了提高情感识别率,本文提取了18个韵律参数和59个音质参数用于识别,为避免特征矢量维度过高而造成的计算量过大和信息冗余,采用主分量分析神经网络(PCANN)进行降维,并用二次判别式进行参数有效性验证.针对二次判别式输入参数正态化这一假设,提出一种改进二次判别式用于四种情感的识别,实验结果表明,改进方法可以有效提高识别率.     

Improving the Flexibility of Dynamic Prosody Modification Using Instants of Significant Excitation

Modification of suprasegmental features such as pitch and duration of original speech by fixed scaling factors is referred to as static prosody modification. In dynamic prosody modification, the prosodic scaling factors (time-varying modification factors) are defined for all the pitch cycles present in the original speech. The present work is focused on improving the naturalness of the prosody modified speech by reducing the generation of piecewise constant segments in the modified pitch contour. The prosody modification is performed by anchoring around the accurate instants of significant excitation estimated from the original speech. The division of longer pitch intervals into many equal intervals over long speech segments introduces step-like discontinuities in the form of piecewise constant segments in the modified pitch contours. The effectiveness of proposed dynamic modification method is initially confirmed from the smooth modified pitch contour plot obtained for finer static prosody scaling factors, waveforms, spectrogram plots and comparison subjective evaluations. Also, the average \(F_0\) jitter computed from the pitch segments of each glottal activity region in the modified speech is proposed as an objective measure for the prosody modification. The naturalness of the prosody modified speech using the proposed method is objectively and subjectively compared with that of the existing zero frequency filtered signal-based dynamic prosody modification. Also, the proposed algorithm effectively preserves the dynamics of the prosodic patterns in singing voices where in the \(F_0\) parameters rapidly and continuously fluctuate within a higher \(F_0\) range.     

基于细粒度韵律建模和条件CycleGAN的非平行蒙古语语音转换方法

语音转换技术在保持语义内容不变的前提下将源说话人的语音音色转换为目标说话人。目前,蒙古语语音转换面临语料匮乏、蒙古语字词在发音上韵律变化丰富等问题。针对这些问题,本文提出一种基于细粒度韵律建模和条件CycleGAN的非平行蒙古语语音转换方法。该方法首先使用连续小波变换提取细粒度的语音韵律特征,然后向CycleGAN中加入说话人向量构建条件CycleGAN,最后使用条件CycleGAN得到源说话人和目标说话人之间稳定的韵律转换。实验结果表明,该方法与传统CycleGAN语音转换方法相比能够有效提升蒙古语语音转换效果,在语音自然度和说话人相似度的MOS评分上分别提升了0.1和0.2。      

Application of Emotion Recognition and Modification for Emotional Telugu Speech Recognition

Majority of the automatic speech recognition systems (ASR) are trained with neutral speech and the performance of these systems are affected due to the presence of emotional content in the speech. The recognition of these emotions in human speech is considered to be the crucial aspect of human-machine interaction. The combined spectral and differenced prosody features are considered for the task of the emotion recognition in the first stage. The task of emotion recognition does not serve the sole purpose of improvement in the performance of an ASR system. Based on the recognized emotions from the input speech, the corresponding adapted emotive ASR model is selected for the evaluation in the second stage. This adapted emotive ASR model is built using the existing neutral and synthetically generated emotive speech using prosody modification method. In this work, the importance of emotion recognition block at the front-end along with the emotive speech adaptation to the ASR system models were studied. The speech samples from IIIT-H Telugu speech corpus were considered for building the large vocabulary ASR systems. The emotional speech samples from IITKGP-SESC Telugu corpus were used for the evaluation. The adapted emotive speech models have yielded better performance over the existing neutral speech models.

     

Beamsteering for Non-uniform Weighted Array-Fed Reflector Antenna

In this paper, a beamsteering scheme for an array-fed paraboloid reflector antenna is proposed. In this method, a non-uniform amplitude weighting strategy is used in order to demonstrate an offset fed for the reflector antenna. Steered beam is kept in shape in terms of half power beam width (HPBW) and relative side lobe level (RSLL). To do so, an analytical derivation of beam pattern is performed for the array-fed reflector antenna. Two standard non-uniform weighting techniques, Binomial and Dolf-Tschebyscheff, are employed for this reason. Finally, a multi-object optimization method is proposed to provide the best weighting. The computer simulations are performed for different multi-object optimization scenarios. The results reveal an improvement beam shape in terms of HPBW and RSLL traditional non-uniform weighing methods.

     

非均匀分布式星载雷达栅瓣抑制技术研究

分布式星载雷达突破了单星雷达受功率孔径积的限制,具有更远的探测距离;突破了单星雷达受天线基线长度的限制,具有更窄的波束宽度,但是会产生较多的孔径干涉栅瓣.文中研究了一种分布式星载雷达的栅瓣抑制方法,该方法采用遗传算法来确定超稀疏的非均匀分布式星载雷达阵列的位置矢量,利用个体的实值编码提高了遗传算法的计算效率.＃在给定卫星阵列基线长度和卫星间最小间距约束的条件下,通过仿真实验验证了该方法抑制栅瓣的有效性.卫星个数越多,栅瓣抑制效果越好.随着小卫星技术的发展以及小卫星成本的降低,文中基于非均匀分布阵列的栅瓣抑制方法对小卫星的分布设计具有一定的参考价值.     

烧结主抽风机高压变频改造研究与应用

本文讲述烧结厂2*180㎡烧结主抽风机高压变频改造.主抽风机是整个烧结生产过程中最重要的生产设备之一,风压、风量变化直接影响烧结矿的生产质量与数量,烧结主抽风机是主要电能消耗设备,基本占到烧结厂总电能的60％以上.运用高压变频器则可以很大程度解决这一问题.经变频改造后,系统运行趋于安全稳定,节能效果显著超预期.     

语音转换中系统单位冲激响应的频谱搬移方法研究

频谱包络转换是语音转换中的一项重要内容,基于双线性转换函数进行频谱搬移的方法可以有效地进行谱包络转换,而且在基于小语料库进行训练时仍能得到稳定的转换谱包络.本文基于LPC分析,提出用反傅里叶变换的方法来求解频谱搬移后的系统单位冲激响应,以此来实现频谱包络的变换,并取得了较好的效果.     

一种非等间距线阵的DOA估计方法

针对非等间距线阵测向中的测向精度和相位模糊之间的矛盾,该文提出了一种基于四阶累积量的波达角(DOA)估计算法。该算法利用基线间的参差关系解相位模糊,以突破VESPA算法中参考阵元间距不大于半波长的限制,从而有效地提高了测向精度。依靠导向矢量、累积量矩阵特征值以及其对应的特征向量三者之间的关系,该算法实现了各基线的相位差与信号源的配对。仿真实验验证了该算法的有效性。     

非均匀采样信号的一种重建方法

本文利用Toeplitz矩阵和循环矩阵对非均匀采样信号提出了一种直接的重建方法,该方法可以直接利用离散傅立叶变换进行,不需要迭代,并且可以实时进行.仿真结果表明该算法是有效的.     

非均匀傅里叶变换频率不变波束形成方法

频率不变波束形成是宽带阵列信号处理研究的重要内容之一。本文以麦克风阵列语音处理为研究对象,针对FIB低频处波束形成一致性不理想的问题,提出了一种基于非均匀傅里叶变换的频率不变波束形成方法。该方法采用非均匀采样来增加低频处的采样点数,构建符合非均匀傅里叶逆变换的范德蒙矩阵,再用优化对称窗函数对变换结果进行截取,得到空时滤波器。该方法不仅实现了低频段与期望波束响应近似的波束图,且降低了阵元数目。计算机仿真实验结果验证了该方法的有效性。      

非合作水雷目标图像非均匀强噪声去除方法

水雷目标探测会受到水下非均匀强噪声（有机质、悬浮颗粒等）的干扰,为了解决这一问题,提出了一种新的去噪方法。首先优化局部保边缘滤波算法,提出了基于边缘感知约束的局部保边缘滤波,在模型中引入了一个空间自适应的边缘感知约束正则化项,用来更好地表征图像的边缘及细节,使得算法的保边缘平滑特性更好。其次针对强噪声的非均匀特性,采用多尺度策略,迭代地将优化后的模型运用到每个尺度的去噪结果上生成多尺度分解,并在多尺度分解的过程中,逐步增加去噪尺度,将不同尺度的噪声逐步从上一尺度的去噪结果中分离出来。实验结果表明,相较于其他经典去噪方法,提出的算法能够在更好地去除水下非均匀强噪声的同时保留水雷目标信息,对实时水雷作业有着一定的指导意义。     

An Applied Method for Designing Maximally Decimating Non-uniform Filter Banks

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Non-uniform wavelets in electromagnetic scattering analysis

Non-uniform wavelets are constructed to benefit from both adaptively refined grids for modelling edge singularities and compression of moment matrices with wavelet bases. They are applied to the analysis of electromagnetic scattering problems     

高通量微流控荧光定量PCR激发光非均匀性研究

研究高通量微流控荧光定量PCR激发光非均匀性问题对提高DNA浓度定量结果的精度具有重要意义。根据荧光定量PCR的原理,分析了激发光非均匀性对Ct值测量精度的影响,给出了激发光非均匀性引起Ct值测量偏差的表达式,确定了激发光强度标准偏差应小于11.56%的要求。根据微流控芯片结构特点及激发光均匀性要求,设计了基于光棒的匀光光路用于解决激发光照度非均匀性问题。模拟及实验所得到的激发光照度的相对标准偏差分别为3.10%、6.01%,二者均小于11.56%。所设计匀光光路能够满足高通量微流控荧光定量PCR的要求。     

一种新型无人机高分SAR 信号非均匀混合采样技术

无人机高分辨合成孔径雷达(SAR)系统具有较大的信号频率带宽,根据奈奎斯特采样定律,雷达接收机需要超高速采样的ADC芯片。由于超高速采样率的ADC芯片的采样量化位数较低、功耗较高、成本昂贵,直接采用超高速采样ADC芯片对无人机高分辨率SAR回波信号进行采样接收不是最优方法。文中提出一种新型的非均匀混合采样技术用于对无人机高分辨率SAR回波信号进行采样接收,通过优化无人机SAR系统的信号收发时序,利用325 Msps采样率的ADC芯片即可对频率带宽为2 GHz的雷达回波信号进行采样接收,保证雷达回波的相位扰动与旁瓣电平满足应用需求。仿真实验表明:2 GHz带宽的Ku-SAR系统的回波信号能被采样率为325 Msps的ADC芯片完好采样接收,成像分辨率优于0. 2 m,旁瓣电平控制在-13 dB以下。     

Dispersion Equation in Non—uniform Optical Waveguide

We study the WKB dispersion equation in non-uniform optical wave-guide.There are three methods given in this paper；(1)method of Airy function；（2）method of connection formula；and（3） method of phase shift.At last we make some re-marks.