一种混合优化的匹配追踪生态声音识别方法

针对生态自然环境中噪声对声音识别产生干扰的问题,提出利用混合优化的匹配追踪(MP)进行生态声音识别的方法.首先,使用萤火虫算法(GSO)和粒子群算法(PSO)对匹配追踪算法进行混合优化,加快匹配追踪有限次稀疏分解的速度并重构声音信号,保留高相关成分,滤除低相关噪声;其次,根据所选最优原子的时频信息结合MFCCs提取复合抗噪特征;最后,结合支持向量机(SVM)对40种生态声音在不同背景噪声与信噪比的情境下进行分类与识别.实验表明,优化后的匹配追踪算法去噪性能优于谱减法和小波去噪法.与常用的MFCCs方法相比,本方法对生态声音在不同信噪比下的识别性能有不同程度的改善,并且具有较好抗噪性.     

鲸类声信号的分类系统设计

针对传统的水声信号分类技术处理方法复杂、特征提取时间长以及特征量多等问题,提出了一种基于稀疏表示的分类系统,先利用正交匹配追踪法(OMP)算法提取与水声信号最为匹配的少数原子作为目标特征,再采用支持向量机(SVM)进行分类.对鲸类声信号进行仿真实验,实验结果表明,不仅提高了压缩效率和运算速度,而且识别率高,在水声信号的实时处理中具有较高的实用价值.     

基于匹配追踪时频LBP谱图的内燃机气门故障诊断方法

为直接对内燃机振动时频图像进行诊断识别,引入图像纹理特征提取技术,提出一种基于振动信号匹配追踪时频局部二值模式谱图的内燃机气门故障诊断新方法。首先,为清晰刻画内燃机时频图像中的各分量信息,利用匹配追踪算法(MP)获取无交叉项干扰项且时频聚集性良好的信号时频表示;然后引入局部二值模式(LBP)生成MP时频表示的LBP谱图,并将LBP谱图的灰度直方序列作为特征参数,利用支持向量机(SVM)对故障状态进行模式识别。在内燃机4种不同气门状态的诊断识别实验中,该方法最高识别率可达99.17%,表明基于MP时频LBP谱图识别的故障诊断方法具有较强的故障特征描述能力,能够准确诊断内燃机气门故障。     

基于Takenaka-Malmquist系的语音信号压缩与降噪方法

语音信号的稀疏表示是语音压缩与降噪等语音处理的关键技术之一.在匹配追踪(matching pursuit, MP)、正交匹配追踪(orthogonal matching pursuit, OMP)等算法的基础上,提出了一种基于Takenaka-Malmquist系的贪婪权值算法(a greedy weight algorithm based on the Takenaka-Malmquist system, TMGW).采用TMGW对语音信号进行重构时只需要较少的分解项数,从而达到语音压缩的目的.同时,根据稀疏分解后信号与噪声在时频面上能量分布不同的特点,该算法可实现对含噪语音的降噪.实验结果表明, TMGW比基于自适应Gabor子字典的匹配追踪算法(matching pursuit algorithm based on the adaptive Gabor sub-dictionary, GMP)更适用于语音信号的稀疏表示.     

融合GMM及SVM的特定音频事件高精度识别方法

针对特定音频事件识别中持续时间特别短的音频事件漏检概率高、识别速度较慢的问题,提出一种融合高斯混合模型（GMM）及支持向量机（SVM）的特定音频事件识别算法. 该方法利用GMM的统计分布描述能力和SVM的推广泛化能力,将GMM和SVM分别识别的结果进行融合处理,以手枪、步枪、机关枪等10类以上枪声为实验数据,无需针对每种枪声生成相应的识别模板,仅需训练生成2个识别模板. 实验结果表明,识别准确率达到92.71%. 该方法模板数量少,不需要多次训练,算法复杂度较低,不仅便于应用而且可大幅提升识别效率.      

基于稀疏表达分类的人脸识别及算法对比研究

基于稀疏表达分类算法(SRC)实现了人脸识别,并与紧邻算法(NN)、支持向量机(SVM)、BP神经网络等传统识别算法进行了比较,SRC的识别率高于这些传统的识别方法.在主成分分析(PCA)等特征提取算法下,比较了稀疏表达中用于重构信号的基追踪算法和贪婪算法的识别率和识别时间.结果表明,l1_ls的识别精度较高,但识别速度慢;在对识别速度要求较高时,可通过同伦算法(Homotopy)求解.针对有遮挡人脸的识别实验表明,利用梯度投影稀疏重建算法(GPSR)可对遮挡人脸进行有效识别.     

一种改进的分段广义正交匹配追踪算法

压缩感知理论是根据信号本身具有的稀疏性提出的新型信号采样理论.为提升正交匹配追踪算法采样信号的准确性和实时性,研究该算法的信号重构算法.分段广义正交匹配追踪算法就是以通过改变原始正交匹配追踪算法筛选原子为依据,达到对正交匹配追踪算法改进的目的.改进算法将原子筛选过程分为2个阶段,不需要已知信号的稀疏度且优化了算法的运行时间,有更准确地恢复初始信号的能力.仿真结果表明,该改进算法的运行时间和对信号的恢复效果均优于正交匹配追踪算法的.     

用于AIS实时信号稀疏表示的追踪算法研究

为解决非周期船舶自动识别系统(AIS)信号的载波跟踪问题,利用信号稀疏表示方法对AIS实时信号进行重构,以获得AIS信号的信道信息,从而为实现定位信息的测量打下基础.从AIS信号特点和AIS实时信号处理的要求出发,对基于K-SVD算法所构造的自适应冗余字典,从信号处理时间、稀疏表示精度、误码率和受噪声的影响几方面对比了基追踪(BP)和正交匹配追踪(OMP)两种不同的追踪算法.实验结果表明,两种算法都能有效精确地重构AIS信号,BP算法相比OMP算法具有更好的稀疏表示精度和误码率,但是信号处理时间会更长.由于AIS对实时性的高要求,OMP算法更适合用于AIS自主定位系统.     

基于匹配追踪的MB-OFDM时域信道估计

针对超宽带信道的稀疏特性,基于MB-OFDM系统提出一种基于匹配追踪的时域信道估计算法(MP-TD).首先利用OFDM数据块的循环卷积特性建立一种时域模型,然后采用匹配追踪(MP)算法探测出非零抽头的位置,最后利用非零抽头位置信息降低了估计维数并通过时域方法估计出信道.仿真证实了算法的有效性.     

基于GA和过完备原子库划分的MP信号稀疏分解算法

信号稀疏分解计算量大是阻碍其实时应用的主要因素.研究基于匹配追踪(Matching Pursuit)方法实现的信号稀疏分解算法,提出了基于过完备原子库集合划分的、分两阶段搜索的、遗传算法快速寻找MP过程中每一步分解的最佳原子,在稀疏分解重建信号质量不变的条件下,提高了稀疏分解的速度.算法的有效性为实验结果所证实.     

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