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基于导波-高斯混合模型蒙特卡罗迁移度量的结构损伤定量化诊断方法研究 被引量:2
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作者 袁慎芳 王劼 +1 位作者 徐秋慧 陈健 《航空科学技术》 2023年第3期33-39,共7页
在线准确定量诊断飞行器结构疲劳裂纹损伤对于保证结构安全、降低维护费用具有重要意义,为了提升复杂服役条件环境下结构损伤定量化诊断的可靠性,本文提出了一种导波-高斯混合模型(Gaussian mixture model,GMM)蒙特卡罗迁移度量的损伤... 在线准确定量诊断飞行器结构疲劳裂纹损伤对于保证结构安全、降低维护费用具有重要意义,为了提升复杂服役条件环境下结构损伤定量化诊断的可靠性,本文提出了一种导波-高斯混合模型(Gaussian mixture model,GMM)蒙特卡罗迁移度量的损伤定量化诊断方法。首先建立表征结构不同状态下导波特征概率分布的GMM,再通过大数据随机采样的蒙特卡罗方法计算监测状态GMM相对于基准GMM的迁移距离,该方法在避免了复杂积分计算的同时,能够更准确地计算GMM的迁移距离,实现复杂服役条件下损伤扩展的准确定量化追踪诊断。选取重要飞行器耳片连接结构进行了孔边裂纹监测,有效实现了裂纹定量化监测,结果表明,相比传统的最小匹配迁移距离计算方法,本文提出的方法使裂纹定量化精度提高了29%。 展开更多
关键词 导波结构健康监测 高斯混合模型 损伤定量化诊断 迁移距离
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核素显像在心血管影像学中的作用
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作者 刘秀杰 《中国医学影像学杂志》 CSCD 1994年第3期130-132,共3页
核素显像在心血管影像学中的作用刘秀杰近20年来,心血管影像学有突破性进展[1],主要表现为以下特点:无创伤性检查技术日新月异,定量化诊断和综合图像分析是今后发展的趋势,模拟化向数字化方向进展,多维图像将逐步取代二维图... 核素显像在心血管影像学中的作用刘秀杰近20年来,心血管影像学有突破性进展[1],主要表现为以下特点:无创伤性检查技术日新月异,定量化诊断和综合图像分析是今后发展的趋势,模拟化向数字化方向进展,多维图像将逐步取代二维图像以便获取多层次、多信息量,将解剖... 展开更多
关键词 核素显像 心血管影像学 定量化诊断 综合图像分析
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Non-invasive determination of hepatic steatosis by acoustic structure quantification from ultrasound echo amplitude 被引量:15
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作者 Hidekatsu Kuroda Keisuke Kakisaka +7 位作者 Naohisa Kamiyama Takayoshi Oikawa Mio Onodera Kei Sawara Kanta Oikawa Ryujin Endo Yasuhiro Takikawa Kazuyuki Suzuki 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第29期3889-3895,共7页
AIM:To use leptin-deficient(ob/ob) mice with demonstrated differences in steatosis levels to test a new diagnostic method using the acoustical structure quantification(ASQ) mode and the associated analytical parameter... AIM:To use leptin-deficient(ob/ob) mice with demonstrated differences in steatosis levels to test a new diagnostic method using the acoustical structure quantification(ASQ) mode and the associated analytical parameter,"focal disturbance ratio"(FD-ratio).METHODS:Nine ob/ob mice,at 5,8,and 12 wk of age(n = 3 in each age group),were used as models for hepatic steatosis.Echo signals obtained from ultrasonography in the mice were analyzed by ASQ,which uses a statistical analysis of echo amplitude to estimate inhomogeneity in the diagnostic region.FD-ratio,as calculated from this analysis,was the focus of the present study.FD-ratio and fat droplet areas and sizes were compared between age groups.RESULTS:No fibrosis or inflammation was observed in any of the groups.The fat droplet area significantly(P < 0.01) increased with age from 1.25% ± 0.28% at 5 wk to 31.07% ± 0.48% at 8 wk to 51.69% ± 3.19% at 12 wk.The median fat droplet size also significantly(P < 0.01) increased with age,from 1.33(0.55-10.52) m at 5 wk,2.82(0.61-44.13) m at 8 wk and 6.34(0.66-81.83) m at 12 wk.The mean FD-ratio was 0.42 ± 0.11 at 5 wk,0.11 ± 0.05 at 8 wk,and 0.03 ± 0.02 at 12 wk.The FD-ratio was significantly lower at 12 wk than at 5 wk and 8 wk(P < 0.01).A significant negative correlation was observed between the FD-ratio and either the fat droplet area(r =-0.7211,P = 0.0017) or fat droplet size(r =-0.9811,P = 0.0052).CONCLUSION:This tool for statistical analysis of signals from ultrasonography using the FD-ratio can be used to accurately quantify fat in vivo in an animal model of hepatic steatosis,and may serve as a quantitative biomarker of hepatic steatosis. 展开更多
关键词 Non-alcoholic fatty liver disease Quantitation of hepatic steatosis Animal model Focal disturbance ratio Acoustic structure quantification Ultrasonography
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