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基于D-H矩阵的柔性坐标测量机多测量模型研究 被引量:5
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作者 吴霞 郑大腾 《电子测量与仪器学报》 CSCD 北大核心 2015年第5期760-765,共6页
柔性坐标测量机使用灵活且携带方便等诸多优点,深受业界人士好评,但因其成本昂贵且精度不高而受到限制。在不增加柔性坐标测量机硬件成本的基础上,为了提高测量精度,提出了多测量模型方法。分析了单个测量模型的不足,研究了多测量模型... 柔性坐标测量机使用灵活且携带方便等诸多优点,深受业界人士好评,但因其成本昂贵且精度不高而受到限制。在不增加柔性坐标测量机硬件成本的基础上,为了提高测量精度,提出了多测量模型方法。分析了单个测量模型的不足,研究了多测量模型的优越性。为了验证多测量模型的有效性,在实验中选取了标准量,给出了采样策略,进行了标定运算。结果表明,在同一采样区间,只带一个测量模型的柔性坐标测量机的测量误差为0.076 3 mm,而带多测量模型的柔性坐标测量机的测量误差为0.041 6 mm;在不同采样区间,只带一个测量模型的柔性坐标测量机的测量误差为0.128 4 mm,而带多测量模型的柔性坐标测量机的测量误差为0.052 3 mm。显然,多测量模型优于单个测量模型,这对于促进柔性坐标测量机的普及应用具有较大的理论价值和实际应用意义。 展开更多
关键词 柔性坐标测量 多测量模型 采样区间 测量精度
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超声全矩阵数据联合稀疏重构的多测量向量模型应用
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作者 严凡 林莉 金士杰 《应用声学》 CSCD 北大核心 2023年第3期523-528,共6页
针对单测量向量模型等传统压缩感知方法处理超声全矩阵捕捉数据时,存在重构精度低和重构耗时长等问题,该文研究了多测量向量模型应用的可行性。针对铝合金试块中不同深度的Ф2mm横通孔,分别使用多测量向量模型中的多测量稀疏贝叶斯算法... 针对单测量向量模型等传统压缩感知方法处理超声全矩阵捕捉数据时,存在重构精度低和重构耗时长等问题,该文研究了多测量向量模型应用的可行性。针对铝合金试块中不同深度的Ф2mm横通孔,分别使用多测量向量模型中的多测量稀疏贝叶斯算法和单测量向量模型中的稀疏贝叶斯算法进行超声全矩阵数据重构,并实施全聚焦成像。随后,引入归一化均方误差和阵列性能因子评价图像和信号的重构效果。实验结果表明,稀疏贝叶斯算法在25%采样率时的归一化均方误差为1.9%,而多测量稀疏贝叶斯算法仅需15%采样率即可达到相似效果且耗时更少。 展开更多
关键词 压缩感知 测量向量模型 多测量向量模型 全聚焦方法 全矩阵捕捉
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多测量向量模型下的修正MUSIC算法 被引量:2
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作者 林云 胡强 《电子与信息学报》 EI CSCD 北大核心 2018年第11期2584-2589,共6页
压缩感知多测量向量(MMV)模型用于解决具有相同稀疏结构的多快拍问题,在传统阵列信号处理应用中多重信号分类(MUSIC)方法是一种常见的方法,但当快拍数不足(低于稀疏度)时其性能将急剧恶化。Kim等人(2012)推导出一种修正的MUSIC谱,并将... 压缩感知多测量向量(MMV)模型用于解决具有相同稀疏结构的多快拍问题,在传统阵列信号处理应用中多重信号分类(MUSIC)方法是一种常见的方法,但当快拍数不足(低于稀疏度)时其性能将急剧恶化。Kim等人(2012)推导出一种修正的MUSIC谱,并将压缩重构方法和MUSIC算法结合提出压缩感知MUSIC算法(CS-MUSIC),能够有效克服快拍数不足的问题。该文将Kim等人的结论扩展到一般情形,并基于传统的MUSIC谱和CSMUSIC谱提出一种修正的MUSIC算法(MMUSIC)。仿真结果表明所提算法能够有效克服快拍数不足的问题,并且具有比CS-MUSIC算法和压缩感知贪婪算法更高的重构概率。 展开更多
关键词 压缩感知 多测量向量模型 联合稀疏 多重信号分类
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Fingerprint singular points extraction based on orientation tensor field and Laurent series 被引量:3
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作者 刘琴 彭可 +4 位作者 刘巍 谢琴 李仲阳 兰浩 金耀 《Journal of Central South University》 SCIE EI CAS 2014年第5期1927-1934,共8页
Singular point(SP)extraction is a key component in automatic fingerprint identification system(AFIS).A new method was proposed for fingerprint singular points extraction,based on orientation tensor field and Laurent s... Singular point(SP)extraction is a key component in automatic fingerprint identification system(AFIS).A new method was proposed for fingerprint singular points extraction,based on orientation tensor field and Laurent series.First,fingerprint orientation flow field was obtained,using the gradient of fingerprint image.With these gradients,fingerprint orientation tensor field was calculated.Then,candidate SPs were detected by the cross-correlation energy in multi-scale Gaussian space.The energy was calculated between fingerprint orientation tensor field and Laurent polynomial model.As a global descriptor,the Laurent polynomial coefficients were allowed for rotational invariance.Furthermore,a support vector machine(SVM)classifier was trained to remove spurious SPs,using cross-correlation coefficient as a feature vector.Finally,experiments were performed on Singular Point Detection Competition 2010(SPD2010)database.Compared to the winner algorithm of SPD2010 which has best accuracy of 31.90%,the accuracy of proposed algorithm is 45.34%.The results show that the proposed method outperforms the state-of-the-art detection algorithms by large margin,and the detection is invariant to rotational transformations. 展开更多
关键词 fingerprint extraction singular point fingerprint orientation tensor field Laurent series rotational invariance supportvector machine (SVM)
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Analysis of external noise spectrum of high-speed railway 被引量:13
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作者 邓永权 肖新标 +1 位作者 何宾 金学松 《Journal of Central South University》 SCIE EI CAS 2014年第12期4753-4761,共9页
A schematic to make the spectra of the exterior noise of high speed railway was put forward. The exterior noise spectrum was defined based on the characteristics of the high-speed train exterior noise. Its characteris... A schematic to make the spectra of the exterior noise of high speed railway was put forward. The exterior noise spectrum was defined based on the characteristics of the high-speed train exterior noise. Its characteristics considered here include identifying the exterior main sources and their locations, their frequency components including the Doppler effect due to the noise sources moving at high speed, the sound field intensity around the train in high-speed operation, the sound radiation path out of the train, and the pressure level and frequency components of the noise at the measuring points specified by the International Organization for Standardization(ISO). The characteristics of the high-speed train exterior noise of the high speed railways in operation were introduced. The advanced measuring systems and their principles for clearly indentifying the exterior noise sources were discussed in detail. Based on the concerned noise results measured at sites, a prediction model was developed to calculate the sound level and the characteristics of the exterior noise at any point where it is difficult to measure and to help to make the exterior noise spectrums. This model was also verified with the test results. The verification shows that there is a good agreement between the theoretical and experimental results. 展开更多
关键词 high-speed train noise sound source identification noise control noise spectrum
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