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1.
一种改进的小波变换信号消噪方法   总被引:5,自引:0,他引:5       下载免费PDF全文
根据小波阈值消噪方法的步骤及特点提出一种新的消噪方法——小波系数放大法,并对该方法进行仿真对比实验。该方法在运用小波变换对含噪信号进行消噪前,先对信号进行小波级数分解,对其中的低频系数和高频系数进行适当的放大,然后对信号采取阈值消噪法进行消噪,最后运用小波变换对所得到的小波系数进行适当的宿小,并将其重构。仿真实验结果表明,小波系数放大法消噪后信号的均方根误差有很大的降低,信噪比提高。该方法优于一般的消噪方法。  相似文献   

2.
从市场响应的角度进行制造企业的敏捷性研究,根据制造企业敏捷性研究的框架模型,提出了制造企业敏捷性的研究方法,应用社会统计方法中的主成分分析对数据进行分析,并应用这种方法对一制造企业进行了实证研究。  相似文献   

3.
高速公路车流量预测方法的研究   总被引:1,自引:0,他引:1  
阐述了高速公路车流量预测研究的意义,并对各种预测方法进行了详细的讨论。通过一个高速公路的实例,对这些预测方法进行了对比分析,并对这些预测方法在高速公路车流量预测问题上的适用性进行了归纳总结。  相似文献   

4.
为了对DTI图像进行正则化,采用了Gaussian-MRF模型。正则化方法根据Bayes准则对图像灰度值进行最大后验(MAP)估计,估计采用模拟退火方法进行,退火温度采用指数冷却进度表。通过对不同加权梯度下的同一层图像(一共7幅)同时进行正则化实验,结果表明该方法能够改善图像的噪声性能。把本正则化方法的结果与对张量场直接进行正则化的结果进行比较,表明采用本方法能够更加有效地减小噪声影响。通过把指数冷却进度表和对数冷却进度表的结果进行比较,表明采用指数温度能够在更短的时间内获得更好的正则化效果。  相似文献   

5.
基于GIS的空间插值方法研究   总被引:47,自引:0,他引:47  
对地理信息系统空间数据分析中的空间数据插值方法从广义的角度分为点的插值和面的插值进行了论述,讨论了点与面的各种插值方法的理论基础、算法以及应用方式,并对空间插值的应用与推广及相关的问题进行了阐述.指出在运用空间插值方法时,要得到理想的空间插值效果,必须针对不同研究区的实际情况,对实测数据样本点进行充分分析,反复试验比较,以选择最佳的方法,并在运用一般插值方法的基础上,依据自身需要及学科的特点,对插值方法进行改进,进而提出适合各学科研究的更优的空间插值方法.  相似文献   

6.
提出一种基于马尔柯夫随机场模型和多层前馈神经网络进行纹理分割的方法,利用二阶高斯MRF模型对图像纹理进行描述,采用最小平方误差方法进行参数估计,将估计参数作纹理的特征向量,并且利用改进的BP算法对特征进行分类。对纹理图像进行了实验表明,与常规距离方法相比,采用这种方法进行纹理分割能取得更好的效果。  相似文献   

7.
卫星结构蜂窝夹层板的等效计算   总被引:29,自引:1,他引:29  
在利用MSC/NASTRAN对卫星结构进行有限元计算时,必须对蜂窝夹层板进行预先的等效处理,等效处理的合理与否将直接影响到计算结果的可信度.为此,研究了3种不同的等效方法,即三明治夹心板理论、蜂窝板理论以及等效板理论,其中三明治夹心板理论方法只对蜂窝夹芯进行等效,而蜂窝板理论和等效板理论方法则是对整个蜂窝夹层板进行等效.分别采用这3种等效方法,对某铝蜂窝夹层板的2种工况进行了模态分析,并将计算结果进行了比较.结果表明,运用等效方法的计算结果非常接近于解析解,证实了等效处理方法的合理性和正确性.  相似文献   

8.
高校体育教学的改革,不仅进行体系、制度、教材、教法的改革,同样需要进行学习方法的改革。总结前人的经验,开拓现代人的思路,使学生掌握了解更多的学习方法势必对教学效果产生更大的影响。因此,对学习方法进行研究和探索,就显得分外重要和具有现实意义。  相似文献   

9.
提出一种基于马尔柯夫随机场 (MRF) 模型和多层前馈神经网络进行纹理分割的方法.利用二阶高斯MRF模型对图像纹理进行描述,采用最小平方误差方法进行参数估计,将估计参数作为纹理的特征向量,并且利用改进的BP算法对特征进行分类.对纹理图像进行的实验表明,与常规距离方法相比,采用这种方法进行纹理分割能取得更好的效果.  相似文献   

10.
低信噪比神经元锋电位信号的分类方法   总被引:1,自引:1,他引:1  
基于离散序列小波变换和主元分析,对低信噪比的神经元锋电位信号提出了新的分类方法。通过对原始信号进行尖峰检测,获得尖峰信号样本,对每个样本进行离散序列小波变换之后,再对小波变换系数进行主元分析,选取主元进行聚类,实现对原始信号的分类。将该方法应用于多电极细胞外记录的小鸡视网膜神经节细胞电活动信号分析,并据此推断出某电极附近的神经节细胞的个数。仿真结果表明,在低信噪比情况下,该方法比单纯通过小波变换进行分类的方法更有效。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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。  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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