Formant coding of speech using dynamic programming

An algorithm is proposed which will obtain, from an input speech signal, formant parameter data to control a parallel formant speech synthesiser. By allowing some delay and employing variable-frame-rate techniques, the parameter data can be obtained at a low frame rate (typically 20 frames per second) suitable for transmission or storage.     

A Low-Rate Digital Formant Vocoder

A complete algorithm of a 1200-bits/s digital formant vocoder system is described. This vocoder algorithm draws heavily on the results of recent research in linear predictive coding. The transmitting parameters are frequencies and amplitudes of the first three formants, the pitch period, voiced/unvoiced decision, and the gain. Formant bandwidths are estimated at the synthesizer by using the amplitude information. The synthesizer structure is in the parallel form. The synthetic speech quality at 1200 bits/s is reasonably good; most of the speech is intelligible and speaker-recognizable.     

一种新的语音信号共振峰提取的算法

本文提出了一种新的语音信号共振峰的提取方法。在LPC幅度谱上搜寻最大的极大值点所对应的频率,并将它作为构成声道参数的某一谐振腔所对应的共轭复根的角度,再通过LPC系数的相—频特性的一次导数和三次导数相结合的方法求出这对共轭复根的幅度,从而确定了该谐振腔,也就得到了该谐振腔的共振峰。然后,用LPC的多项式对该谐振腔所对应的多项式做多项式除法,得到新的LPC系数,接着重复前面的步骤,可以较好地求出在LPC谱中对应幅度最大的两个共振峰。     

基于跟踪共振峰的语音增强算法

该文通过实验方法研究和分析了汉字语音共振峰的特点,发现可跟踪并找到各个共振峰,结合汉字发音所具有的一般规律,提出了一种基于跟踪共振峰的语音增强算法。该算法能够有效地识别出带噪语音中的语音帧和非语音帧,简单且有效地去除非语音帧的全部噪声,明显抑制语音帧内的噪声。算法计算复杂度低并具有噪声环境可移植性。     

利用频谱搬移控制语音转换中的共振峰

在研究频谱搬移方法和分析语音共振峰性质及变化规律的基础上,提出了利用频谱搬移调整共振峰的算法,能有效控制共振峰轨迹合成声道模型。讨论了语音转换的实现流程,并将合成的声源模型应用于男、女声之间的转换,实验结果和分析表明,该方法可实现对共振峰的灵活控制,使语音转换具有更高的融合度。     

LPC方法提防语音信号共振峰的分析

通过对ＬＰＣ（线性预测编码）方法提取语音信号共振峰进行的研究表明,采用相一频特性与对数幅－频特性同样能提取语音信号共振峰。与对数据－频特性的二次导数相比,相－频特性的三导数有更高的频率分辨率,能更有效地解决共振峰合并的问题,撮更精确的共振峰参数。     

一种基于共振峰提取的多通道响度补偿算法

共振峰是语音信号的一个重要特征,对提高耳聋患者的语言识别率具有重要意义。然而,目前数字助听器领域常用的响度补偿算法（多通道响度补偿和宽动态压缩）均对共振峰结构具有一定的破坏性,对患者听懂语音十分不利。本文结合共振峰检测,提出一种基于共振峰提取的多通道响度补偿算法,在原有多通道响度补偿的基础上,通过对滤波器组的重新设计并加入共振峰提取模块对共振峰予以保护。仿真结果证明,该算法对4类常见患耳均能达到满意的补偿效果,同时,与多通道响度补偿和宽动态压缩两种方法比较,该算法在保护共振峰结构完整性方面性能更优。      

Image label transfer: Short video labelling by using frame auto-encoder

The number of short videos on the Internet is huge, but most of them are unlabeled. In this paper, a rough labelling method of short video based on the neural network of image classification is proposed. Convolutional auto-encoder is applied to train and learn unlabeled video frames, in order to obtain the feature in certain level of the network. Using these features, we extract key-frames of the video by our method of feature clustering. We put these key-frames which represent the video content into the image classification network, so that we can get the labels for every video clip. We also compare the different architectures of convolutional auto-encoder, while optimizing and selecting the better performance architecture through our experiment result. In addition, the video frame feature from the convolutional auto-encoder is compared with those features from other extraction methods. On the whole, this paper propose a method of image labels transferring for the realization of short video rough labelling, which can be applied to the video classes with few labeled samples.     

倒谱在语音的基音和共振峰提取中的应用

同态系统解卷积实现了将卷积关系变换为求和关系的分离处理过程,将语音信号进行同态分析后得到其倒谱参数。它对于分析基音频率和共振峰频率有非常好的效果。该文给出了用倒谱分析基音频率和共振峰频率的实例以及使用倒谱分析两种频率应注意的地方。     

基于语音频谱的共振峰声码器实现

共振峰声码器因其在理论上具有最低码率而一直是参数语音编码算法研究的重点。共振峰编码器的关键算法是基频和共振峰等语音参数的提取。在高分辨率语谱图基础上,利用语音信号的频域特性设计了一种简单有效的基频和共振峰提取算法。通过评价重建语音信号的音质,证明了参数提取算法的准确性。根据语音实验确定编码参数包含基频和前4个共振峰,并在保证语音质量的前提下制定各参数的量化指标。应用实际语音信号对算法的性能进行测试,试验结果证明算法在码率为1 400 b/s时具有良好的语音质量。     

维吾尔语四音节元音和谐词的共振峰模式研究

维吾尔语属阿尔泰语系突厥语族,其共振峰频率参数是语音识别和语音合成的重要依据。首次运用实验语音学的基本理论和方法,在“维吾尔语语音声学参数数据库”的办公环境语料条件下,对维吾尔语四音节元音和谐词进行了统计分析,给出了维吾尔语元音共振峰频率参数和分布规律,并通过四音节元音和谐词实验结果,用实验数据验证了其共振峰频率分布的口耳之学规律。为参数式或波形拼接式语音合成系统中调整合成前的元音和谐问题提供了重要的参考依据。     

Region-growing approach to colour segmentation using 3D clustering and relaxation labelling

The paper presents a new segmentation algorithm for colour images based on a series of region growing and merging processes. This algorithm starts with the region growing process, which groups pixels into homogeneous regions by combining 3D clustering and relaxation labelling techniques. Each resulting small region is then merged to the region which is the nearest to it in terms of colour similarity and spatial proximity. One problem with region growing is its inherent dependency on the selection of the seed region, which can be avoided by using the relaxation labelling technique. Experimental results are presented to demonstrate the performance of the new method in terms of better segmentation and less sensitivity to noise, and in terms of computational efficiency. The segmentation results using the fuzzy c-means technique, the competitive learning neural network and a region growing and merging algorithm are also presented for comparison purposes.     

SAR-ocean wave inversion using image cross spectra

Image cross-spectra obtained by combining pairs of single look SAR images are utilized in an inversion scheme for extracting the underlying ocean wave spectrum. The reasons for proposing the use of image cross-spectra instead of standard multilook spectra are twofold. First, the image cross-spectra are shown to significantly reduce the speckle noise level while preserving the spectral shape. Second, the image cross-spectra provide information about the wave propagation direction. A closed form expression of the ocean-to-SAR spectral transform and its inversion is formulated for the cross-spectral case. The inversion method is based on computing the full derivative of the nonlinear ocean-to-SAR image cross-spectral transform. The SAR image cross-spectra are shown to yield a SNR typically 16-25 dB higher than the corresponding standard 3 look image spectra. The noise level is typically reduced with a factor of 20 compared to the 3 look spectra and a factor of 60 compared to the single look spectra. The inherent information about the wave propagation direction is utilized in the inversion scheme to resolve the 180-degree ambiguity without using any external information. The method is demonstrated on airborne C-band SAR data     

剧院建筑声学设计中"歌手共振峰"问题研究

通过对"歌手共振峰"的分析以及对杭州2006世界休闲博览会主会场3200座水世界大剧院的实例应用,对剧院建筑声学设计中"歌手共振峰"问题进行了研究。结果表明:在现代剧院及多功能厅堂建筑声学设计过程中,建筑声学设计师在考虑了混响时间等参数指标的前提下,如果还能兼顾考虑"歌手共振峰"等音乐的某些特征,那么,剧院最后达到的声学效果远超出了有关厅堂的声学设计指标的意义。     

Pitfalls in the double labelling immunoelectron microscopy using one face of the grid.

We compared two procedures in the double labelling immunoelectron microscopic method of hormone-storing cells: one-faced and two-faced procedures. With the two-faced procedure we got convincing results consistent with morphological finding, while we often got false results with the one-faced procedure. By the misleading one-faced procedure, the cell storing any one hormone will be misinterpreted as a multihormone storing cell. Therefore, it is concluded that the two-faced method is safer for the double labelling immunoelectron microscopic study.     

Temperature dependence of Si-GaAs energy gap using photoconductivity spectra

In the present work, we study the Energy gap (E_g) of the Si-GaAs at various temperatures in the range from 250 up to 350 K, using the photoconductivity method, in order to find the relation between the E_g and the temperature. We have measured the photocurrent as a function of photon energy from 1.36 up to 1.55 eV for each temperature. From the analysis of the spectra for each temperature we have found three peaks corresponding to inter-band transitions and we plotted the energy that corresponds to the peaks as a function of temperature.     

Fault detection of plasma etchers using optical emission spectra

The objective of this paper is to investigate the suitability of using optical emission spectroscopy (OES) for the fault detection and classification of plasma etchers. The OES sensor system used in this study can collect spectra at up to 512 different wavelengths. Multiple scans of the spectra are taken from a wafer, and the spectra data are available for multiple wafers. As a result, the amount of the OES data is typically large. This poses a difficulty in extracting relevant information for fault detection and classification. In this paper, we propose the use of multiway principal component analysis (PCA) to analyze the sensitivity of the multiple scans within a wafer with respect to typical faults such as etch stop, which is a fault that occurs when the polymer deposition rate is larger than the etch rate. Several PCA-based schemes are tested for the purpose of fault detection and wavelength selection. A sphere criterion is proposed for wavelength selection and compared with an existing method in the literature. To construct the final monitoring model, the OES data of selected wavelengths are properly scaled to calculate fault detection indices. Reduction in the number of wavelengths implies reduced cost for implementing the fault detection system. All experiments are conducted on an Applied Materials 5300 oxide etcher at Advanced Micro Devices (AMD) in Austin, TX     

Regularized estimation of mixed spectra using a circularGibbs-Markov model

Formulated as a linear inverse problem, spectral estimation is particularly underdetermined when only short data sets are available. Regularization by penalization is an appealing nonparametric approach to solve such ill-posed problems. Following Sacchi et al. (see ibid., vol.46, no.1, p.32-38, 1998), we first address line spectra recovering in this framework. Then, we extend the methodology to situations of increasing difficulty: the case of smooth spectra and the case of mixed spectra, i.e., peaks embedded in smooth spectral contributions. The practical stake of the latter case is very high since it encompasses many problems of target detection and localization from remote sensing. The stress is put on adequate choices of penalty functions: following Sacchi et al., separable functions are retained to retrieve peaks, whereas Gibbs-Markov potential functions are introduced to encode spectral smoothness. Finally, mixed spectra are obtained from the conjunction of contributions, each one bringing its own penalty function. Spectral estimates are defined as minimizers of strictly convex criteria. In the cases of smooth and mixed spectra, we obtain nondifferentable criteria. We adopt a graduated nondifferentiability approach to compute an estimate. The performance of the proposed techniques is tested on the well-known Kay and Marple (1982) example     

Estimation of ocean wave spectra using two-antenna SAR systems

Data from synthetic aperture radar, (SAR) systems can be used to estimate ocean wave directional spectra, but the method is limited by nonlinearities associated with the velocity bunching mechanism and the azimuth falloff effect, which reduces the range of azimuth wavelengths that can be observed. A theoretical analysis which suggests that the use of two or more receive antennas, spaced in the along-track direction, may reduce these limitations is presented. Specifically, the band of usable azimuth wavenumbers is shifted by an amount proportional to the antenna spacing, so that a broader range of wavenumbers can be covered by combining the spectrum obtained from the two-antenna signals with the conventional image spectrum     

激光辐照GaAs膜的光透射谱实验研究

GaAs薄膜材料生长技术的迅速发展和成熟及其广泛应用,该材料性质及其在外部电磁场等条件下的变化的广泛研究,促使以GaAs多层膜为结构的光电子元器件和集成光学元件以及相关的集成光电子技术和光计算技术等高科技研究和实用化的飞速进展,其中GaAs膜材料的光学性质,尤其是激光与GaAs膜的相互作用,影响其光学性质的研究是极其有用的。本文报道He-Ne激光辐照金属有机氧化物气相外延(MOVPE)技术生长的不掺杂GaAs膜,其光透射性质发生变化的实验研究结果。