オープンキャンパス初日、朝6時に息子にたたき起こされ、ラジオ体操第１＆第２につき合わされた後メールを確認すると、うれしい知らせが届いていました。昨年度参加したISEM2025のFull PaperのInternational Journal of Applied Electromagnetics and Mechanics誌1への掲載決定通知です。こちらの内容自体は2023年度2に修士修了した池田君の修士論文をベースにしたものでした。いい内容なのに論文としてまとめず終わらせてしまうのは惜しい、ということでISEMでの発表→今回の論文、となりました。時間はかかりましたが、池田君の修士研究がこのような形で残せたのは嬉しいことです。
概要は以下。
Title: Evaluating the effect of error in thickness evaluation on the reliability of pipe remaining life prediction
Abstract: Background: Accurately estimating the remaining life of pipes affected by wall thinning relies on ultrasonic testing (UT). However, unpredictable measurement errors can complicate these estimations, and assuming normally-distributed errors may not always be justified. Purpose: This study examines the impact of unpredicted UT measurement errors on pipe life estimation and explores suitable predictive models under realistic error assumptions. Methods: Thirty artificially corroded plate samples were tested using conventional UT with a 5 MHz transducer, conducted by an unqualified operator. The distribution of measurement errors was assessed. Simulations modeled annual UT measurements for a virtual pipe over ten years, predicting thickness in the 10th year using either linear regression or Bayesian inference. Results: The analysis showed that the UT measurement errors did not follow a normal distribution, indicating limitations in using traditional statistical models. Simulations demonstrated that Bayesian inference consistently produced more reliable predictions of pipe thickness across different error models, outperforming conventional linear regression. Conclusion: Assuming normality in UT error distribution is not appropriate in all cases. Bayesian inference offers a more robust and reliable approach for predicting the remaining life of pipes under uncertain error conditions compared to conventional methods.