基于EEMD-ICA-CWT的装载机室内噪声盲源分离和识别

为了分离装载机的噪声源,采用集合经验模态分解(EEMD)、独立分量分析(ICA)和连续小波变换(CWT)技术相结合的方法,对装载机司机位置处噪声信号进行了盲源分离和声源识别研究.针对单一通道噪声信号进行盲源分离,将其分解成一系列独立分量.在削弱了传统经验模态分解(EMD)算法处理噪声信号时产生的模态混叠现象的同时,克服了独立分量分析方法要求传感器数目必须大于等于分离出分量数目的限制;借助连续小波变换良好的时频定位特性,对ICA分离结果进行时频分析.结合时频分析结果和各噪声源信号的频谱结构,确定了各独立分量与装载机不同噪声源的对应关系.结果表明,这些独立分量分别对应着装载机的燃烧噪声、冷却风扇辐射噪声及排气噪声等噪声源.     

基于小波分析的盲源分离

提出一种新盲源（BSS）分离算法是在独立分量分析（ICA）算法中引入离散小波变换技术分解出有用信号．ICA是一种线性非高斯统计方法,不仅能够使研究对象相互独立或尽可能独立,而且能突出源信号的本质结构．笔者采用的新盲源算法能够将时-频ICA相结合,实现了较好的盲源分离．     

基于独立分量分析的混合声音信号分离

论文简要介绍了有关独立分量分析（ICA）的基本理论和算法;探讨了独立分量分析在混合声音信号分离中的应用。针对ICA输出结果排序的不定性以及在长时间记录声音信号的过程,ICA混合模型系数存在时变性等问题,提出了一种结合小波变换和独立分量分析的解决方法;试验结果表明,该方法能有效地提高运算效率并获得较好的分离效果。     

应用独立分量分析提取机器的状态特征

以大型轧钢机和滚动轴承试验台为研究对象，应用独立分量分析方法分离机器的声音信号，并提取其状态特征，同时指出，对信号进行自相关预处理，可以突出信号的非高斯成分，较好地满足独立分量分析的前提条件，即源信号统计独立，因此，采用基于峭度的快速独立分量分析（ICA）算法，成功地分离出了信号的一些独立成分及对应的发声零部件，研究结果表明，根据信号结构选择预处理的方法十分重要，正确的预处理可以使独立分量分析有效地提取机械信号中的特征。     

盲信号分离输出与源信号的一致性判断

针对盲信号分离需要判断分离结果与源信号是否一致的问题,基于统计独立变量函数仍然保持“统计独立”的性质,提出了独立分量分析(ICA)的输出分量与源信号的一致性判断方法.该方法通过计算混合信号及其差分值混合矩阵的相关矩阵,根据ICA各分量对应的最大相关系数来判断ICA各分量与源信号的一致性.模拟计算和实验结果表明:若差分前后混合矩阵的最大相关系数趋近于1,则ICA输出分量与对应的源信号一致;为保证分离的准确,差分前后混合矩阵的最大相关系数不应小于0.8.     

基于独立分量分析的缺陷信号除噪

独立分量分析ICA是一项新兴的阵列信号处理方法,在简要介绍ICA概念和定点算法的基础上,将ICA的定点算法应用到缺陷信号除噪中。仿真试验结果表明,ICA的定点算法除噪效果优于传统的数字滤波器,它在缺陷信号除噪中具有较大的应用潜能。     

基于改进PSO的ICA方法分析重力固体潮信号

为了从重力固体潮信号中提取地球物理信息,介绍了一种重力固体潮信号分解模型.在分解模型中,重力固体潮信号分解为赤道平面信号分量及地球自转轴信号分量.为了提取与分解模型相一致的地球物理信息,提出用独立分量分析(ICA)方法将重力固体潮信号中的赤道平面信号分量与地球自转轴信号分量分离.鉴于ICA存在收敛速度慢及局部搜索等特点,提出了一种基于惯性因子ω的改进粒子群优化算法(PSO)来解决ICA中的全局寻优问题.通过仿真实验分析可知,本文提出的改进粒子群的独立分量分析算法可以获得与分解模型相一致的信号分量,并且从各分量中可提取出与地球产生机制相一致的地球物理信息,是一种分析重力固体潮信号的有效方法.     

独立分量分析联合小波变换的多分量信号调制识别研究

对复杂电磁环境下多分量信号进行调制识别,可通过准确估计接收信号的瞬时频率来分析其脉内细微特征。本文联合独立分量分析和小波变换技术,对多分量辐射源信号进行了盲源分离和调制识别的研究。在无先验信息条件下,采用Fast ICA对混叠信号分离,将时频混叠信号分解成一系列独立分量。对分离后的单分量信号分别做小波变换处理,由小波系数的局部模极大值提取其小波脊线。针对不同调制类型雷达信号,用最小二乘法对时频小波脊线进行直线拟合,获取特征参数,通过计算特征值判决出信号的调制类型。通过仿真实验表明,该方法可以分离混叠信号并有效提取信号小波脊和瞬时频率,进而识别出信号的调制类型,并在低信噪比情况下仍有较高的识别概率。     

超定独立分量分析及其在结肠压力信号分析中的应用

针对传感器个数大于源信号个数的情况,提出了一个超定独立分量分析(ICA)方法,并将其应用到人体结肠压力信号分析中.首先对结肠压力信号运用主成分分析(PCA)估计源信号个数,并将观测信号进行降维使其维数与源信号相等,从而将超定ICA问题转化为一个完备ICA问题;最后通过快速ICA算法估计出源信号.实验采用26组人体结肠压力数据,成功提取出结肠活动中具有生理意义的动力模式信号.     

一种引入虚拟噪声分量的独立分量分析语音增强算法

简要介绍了有关独立分量分析(ICA)的基本理论和算法后,探讨了独立分量分析在语音增强中的应用。针对在加噪模型中进行ICA分离时,噪声消除比较困难这一问题通过理论分析,引入了虚拟高斯白噪声的概念,将其应用在ICA的语音增强算法中得到了解决。仿真试验结果表明,该方法能有效地消除语音信号中的白噪声。     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.