2020 年から田口玄一に関わる過去のエピソードを聞くというテーマをシリーズで続け，田口伸，鴨下隆志，中島建夫らの各氏，また岐阜県の研究会と併せて4 回行ってきたが，今回は田口が活動の主戦場の一つとしてきた日本規格協会における活動の一端について，1970 年代から真横で見聞きをしている中泉純氏に話を聞きたい。40 年以上も前のことなので，読者になじみのない人物も登場するが，QCの世界では伝説的人物で，また田口を支えてきたという背景もあるため，そのまま掲載を行うこととした。なお敬称については極力初出までとして割愛し，発言内の記載については一部残した。

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The authors are engaged in basic studies of nonthermal plasmas created by electrical discharges in the form of ultra high-power pulses with nanosecond pulse widths and rise times, and in applied studies of high-efficiency ozone generation systems for uses such as environmental cleanup, taking the energy efficiency of ozone generation as an index for the evaluation of results. Noting that in previous studies, this efficiency was determined by chemical ozone generation and breakdown reactions, both of which are due to collision with electrons, and also by thermal breakdown, we carried out a series of experiments in which we clarified the effects of the many factors involving injected energy, ionizer structure, and so on, and found the energy efficiency of our ionizer to exceed that of the processes currently in general use. Translating these results into a practical ionizer, however, will require still higher efficiency without backtracking; that is, the ionizer must be able to produce the theoretical results consistently. In the present study we used parameter design to optimize ozone production in a proprietary experimental device by determining the ionizing conditions that maximize the concentration of the resulting ozone, and the reproducibility of the S/N ratio.

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From May to August 2020, during the Covid-19 crisis, the authors used remote lectures to teach parameter design to 150 students taking the second-year mechanical engineering course offered by the engineering department at the Saitama Institute of Technology. To get the students to discover the effects of control factors and experimental error on their own, they were asked to carry out paper helicopter experiments at home, and were challenged to use parameter design to exceed the performance of an educational paper helicopter described by NASA. Completed reports were submitted by 124（83 ％）of the students who took the course. More than half of them said that the course had changed their view of fluid dynamics and the mechanics of materials, and expressed an interest in taking face-to-face courses in these subjects if available, or said they wanted to use these experiments in their bachelor’s or master’s theses. Here we describe the aims and specific content of the remote lectures, the students’ reactions during the course, the submitted reports, the feedback provided to them, and the results obtained.

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