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natural weight 容積重。

natural-born

Compared with straight ray tracing , inversion of bending ray tracing is better when data of test are accurate . on the other hand , natural weight is introduced and numerical simulations and experiments of wlm on inversion of velocity and attenuation are also made , which show that wlm , with resistance of noises and convergence of iteration , may get good re - construction images 本文引入了物理意義明確的自然權,對基于自然權的加權阻尼最小二乘反演算法( wlm )在速度反演、衰減反演中進行了數值模擬和試驗研究,結果表明wlm均能獲得良好的重建圖像,迭代收斂,抗噪能力強。

Different algorithms were compared in the numerical simulation and model experiment of concrete velocity inversion the results showed that , compared with the least - square solutions and the damped least - square solutions , the damped and natural weighted least - square solutions reflected the inner defections of the tested object more reliably and exactly due to the usage of correct priori information , which benefited the suppression of noises and made the iterations of inverse stable and convergent 結果表明,相對于最小二乘法和阻尼最小二乘法,基于自然權的加權阻尼最小二乘算法,由于利用了正確的先驗信息,不但使反演過程收斂,而且具有數值穩定、抗噪能力強的優點,其成像結果能真實有效地反映對象內部缺陷,因此更適用于混凝土的超聲波速度反演。

Considering the nonuniqueness and instability of ultrasonic computerized tomography for structural concrete as well as the ultrasonic transmission characteristics in concrete , a natural weight matrix with dear physical meaning was introduced in the inverse algorithm 摘要針對混凝土超聲波層析成像結果不唯一和穩定性差的問題,首先依據超聲波在混凝土中的傳播特點,在反演算法中引入物理意義明確的自然權矩陣,對走時較小的射線和射線較密的成像單元加以重權。