一种基于混合MELP/CELP的4 kbit/s声码器

利用混合激励线性预测 (mixed excitation linear prediction,MELP)算法和码激励线性预测(code excitation linear prediction,CELP)算法的优点,提出了一种混合MELP/CELP语音编码模型.编码端对强浊音帧采用MELP编码,对弱浊音帧和清音帧进行CELP编码.MELP编码器采用相位对齐技术提取强浊音帧的相位参数,解决了合成语音与原始语音在时间上不同步的问题.对实现的4 kbit/s混合MELP/CELP声码器进行客观MOS(mean opinion score)值和主观DRT(diagnostic rhythm test)清晰度测试,结果表明,该声码器的合成语音具有较高的可懂度和清晰度.     

FS-1016 CELP语音编码的算法仿真

FS-1016 CELP是一种典型的低速语音编码标准,在保密电话等各种通信业务中有着广泛的应用前景。文章首先介绍了FS-1016 CELP语音编码的算法,然后通过录制一段男声语音,并取语音的前2帧数据为例,用MATLAB 7.0和Borland C Builder 6对CELP算法进行了仿真。仿真结果表明,该算法在较低码率下可获得较高的合成语音。     

基于Linux平台上线性预测语音编码器性能分析

线性预测编码器是一类非常重要的语音编码器。文中主要描述了几种线性预测语音编码算法的软件及实现,即码激励线性预测编码(CELP)、低延迟CELP(LD-CELP)和混合励磁线性预测(MELP),编码速率分别为4.8、16、2.4kb/s。几种语音编码器的C语言程序已在Linux平台上可编译和执行,并对结果进行了以MOS为标准的主观测试。波形分析主要使用了Praat和Adobe Audition软件。结果表明,MELP和CELP的质量相当,而LD-CELP编码器的质量则要高得多,虽然是以牺牲较高的比特率为代价。     

基于电力载波通信的低码率语音压缩编码的方法及分析

近年来,由于数字通信及其他商业应用的需求,语音压缩技术得到了迅速发展,针对目前几种具有代表性的低速率语音压缩编码算法(如:LPC声码器,CELP,MBE,PWI,小波变换等)进行分析和比较,介绍各自的基本原理,并在此基础上分析了各自的优、缺点及实际应用.     

一种基于MELP的1.2kb/s语音编码算法

混合激励线性预测MELP编码方法结合混合激励、多带激励以及原型波形内插等编码方法的优点,成为低码率语音编码的研究热点,该方法可以很好的模拟自然语言,在低速率上合成出较高质量的语音,本文以该算法作为基本模型,对参数的内插、高效的矢量量化、多帧联合几项关键技术进行了详细的分析,给出了实现1.2kbps语音编码的算法,并对算法进行了仿真,从仿真结果可以得出该算法具有可行性。     

基于增强保护帧的G.722.2丢帧补偿算法

运用基于离散Teager能量算子的浊音端点检测技术,将浊音端点及其之后的若干帧作为丢帧补偿的增强保护帧.在研究窄带语音帧间独立编码算法iLBC的基础上,对G.722.2编码标准进行改造,使之能够对宽带输入语音进行类似的帧间独立编码,以增强其抗丢帧鲁棒性.针对不同的丢帧率,对不同数目的增强保护帧进行帧间独立编码,以编码速率的略微提高增强对丢帧的鲁棒性,因此本算法既有iLBC的鲁棒性,又有一般CELP编码的速率自适应性.实验结果表明,相对于G.722.2编码标准附件Ⅰ补偿方法,本算法可以提高丢帧补偿性能,在浊音端点丢失率较高的情况下的效果更好.     

CELP编码器的实现及其在TTS系统中的应用

在对最新的MPEG4中的音频编码中码激励线性预测CELP（code excited linear predicive）编码器分析和研究的基础上,根据其窄带语音编码器的参数模式,建立和实现了一个基于CELP的语音编码实验系统,将高效的CELP编码技术应用于文语转换TTS（text-to-speech）系统中语音数据库的压缩,效果是满意的。     

多普勒信号压缩编码研究

该文在分析了多普勒信号的特性以及与语音信号的区别后 ,采用自适应离散余弦变换算法对多普勒信号进行了压缩编码 ,在中等编码速率下得到了较好的压缩编码效果。文中提出了相关 -自适应离散余弦变换 (C -ADCT)压缩编码方法 ,改进算法提高了自适应离散余弦变换算法的抗噪性能     

低延迟10kb/s语音编码算法研究

介绍了8kHz采样率下算法延迟为2.5ms的10kb/s语音编码算法。本算法使用20维的CELP,并用自适应码本搜索和代数码本搜索相级联的方法进行矢量量化。通过PC仿真实验并经PESQ测试,其合成语音质量接近16kb/s的G.728。     

4kb/s低速率语音编码的一种新算法

4kb/s低速率语音编码是近年来语音信号处理研究的重要课题,也是ITU－T下步要标准化的重点,介绍了目前4kb/s低速率语音编码的最新进展,关重分析了基音位置同步码激励线性预测编码（PPS－CELP）的原理和结构,并与G.729、G.723.1等算法进行了性能比较。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that