Takai Yuka

Artisans and athletes have the tacit knowledge, such as skills and tips that their bodies have learnt. These skills usually require a long apprenticeship. We thought the TF-IDF could be used to visualize tendency and frequency of mistakes made by beginners and investigated whether the TF-IDF could be used from data on past Sakan work.

In the checking phase of automobile repair painting, the position from which the experts see the painted surface was clarified using three-dimensional motion analysis. The expert stood approximately 1200 mm away from the damaged area and looked at the damaged area without lowering the head.

Auto repair sheet metal work refers to the work of repairing a damaged part without replacing any of them. Repair technicians are required to have a high level of skill and to be able to work flexibly. If the work of experts can be quantified and visualized, it may be possible to transfer the skills to non-experts in a shorter time. Thus, in this study, technicians repaired a dent made on the press line of a passenger car fender using a hammer and dolly. The purpose of the research is to analyze the working time and working process during the repair. The sheet metal repairs were classified into five steps: “Hammering” (H), “Adjustment and position check of the dolly” (D), “Check by hand” (CH), “Check by eye” (CE), and “Other” (O). It was found that experts tend to spend longer than non-experts on step D.

In this research, motion analysis was carried out to formalize the practical backing technique of experts and to impart to understanding to non-experts. When mounting a hanging scroll in Japan, three types of “washi”, Japanese paper are layered. Also, to apply those papers, wheat starch is mixed with water and heated until it is gelatinized and used as an adhesive agent. Further, to increase flexibility, wheat starch paste has been stored in a cool dark place for about 10 years. We were able to conduct a new method of three-dimensional motion analysis on traditional techniques in this research, and investigated whether this leads to better education of the non-experts. We have confirmed that results of the motion analysis that visualize the postures during the operation have had a positive influence on the non-expert.

In this study, we analyze the techniques of experts and non-experts as a hairdresser and compared their skills based on eye tracking technology. The first purpose of this research is to clarify the differences between the beauty skills of experts and non-experts. The second purpose is to provide the findings to assist in the development of building educational programs for beauty skills of non-experts. In this study, the characteristics of experts were indicated based on video recording, eye tracking technology, and interview survey from experts.

In this study, the skill of automotive engineers in sheet metal repair is analyzed. Because no two damage situations are identical, every damage is reconsidered on a case-to-case basis, and flexible responses are required. This work requires considerable human technical skill and relies on experienced workers. When the skills depend on experience, human resource development is essential to impart such skills. The overall objective of this research is to propose a personnel training tool. The fender of an automobile was repaired by workers by a sheet metal working technique. The results showed that the experts initiated their strikes in the peripheral part of the dents. Thereafter, they applied several broad strike patterns in their repairs: for example, avoiding striking the peripheral part of the dent; striking the central part while avoiding the press line, followed by striking both the peripheral and central parts; and applying many strikes on the press line in the central part of the dent.

The purpose of this measurement was to separately elucidate each muscle movement made by the expert and the non-expert. Furthermore, this study also verifies the muscle fatigue of each subject by calculating the percentage of maximum voluntary contraction, %MVC. By supporting the assumption that compared to a non-expert an expert can carry out the work more efficiently through the measurement results - which showed clear differences in the subjects' muscle movements and muscle fatigue - we hope to contribute to developing technical skill acquisition guidelines for non-experts.

The objective of the present work is to fabricate Urushi-like glass fiber reinforced plastic (GFRP) by using black silk fabric. We first manufactured a GFRP molded plate consisting of various laminate layers, and compared the surface color with that of Urushi products. Subsequently, we used impression evaluation to reveal how the GFRP plate fabricated using the black silk fabric was rated. The study results confirmed that L* and a* values of the GFRP sample were similar to those of the Urushi sample. In the impression evaluation, almost half of the subjects considered the GFRP sample fabricated using the black silk fabric (with lightness similar to that of the Urushi product) as the original Urushi product. The subjects also associated more “beauty,” “sense of luxury and high quality,” and “depth of blackness” with the sample regarded as the Urushi product than with the sample not regarded as the Urushi product.

オートクレーブ成形のプリプレグ積層工における熟練技術者の特徴を明らかにすることを目的とした。プリプレグ積層工程での作業を撮影し、作業分析を行った。さらに、熟練技術者へのヒアリングを行い、各作業を行う理由を明確化した。この結果、熟練技術者はコーナー積層において、折り紙を折るようにプリプレグシートを折りたたみ、プリプレグシートに折り目を付けることで、プリプレグシートの成形型への密着性を向上させ、的確にハサミでのプリプレグシートの裁断を行っていた。さらに、ドライヤーの使用を必要最小限にすることで、プリプレグシートの熱軟化と粘着性を制御しながら賦形性を向上させ、不要なプリプレグシートの粘着を防止していた。

In the process of plastering an intermediate layer on an earth wall, the actions of the plaster craftsperson were focused on and the characteristics of this task were codified making tacit knowledge explicit. The codified data was then used to develop e-learning materials to support the acquisition of technical skills and this system’s effectiveness was subsequently evaluated. The e-learning materials were targeted at beginners with one or two years experience. Under the supervision of a currently working plaster craftsperson, the course included content on how to use the trowel, the work process, and aspects that are clarified through three-dimensional motion analysis, muscle activity analysis, and eye movement analysis. The beginner students were used to evaluate the e-learning materials. The areas evaluated were their posture when working and fatigue before and after work. The results showed a trend toward a lessening of mental fatigue through the use of the e-learning materials.

This article was retracted. See the Notification.

絵画や書跡の裏面に接着する数枚の裏打ち作業の内,2層目の和紙の接着である「増裏打ち」と呼ばれる工程に注目する。そこで用いられる材料と,それを用いて行う接着作業の熟練度についての評価を様々なサンプルによる剥離試験によって行い,材料と技術の効果を検証した。また,作業現場では打刷毛を用いた叩打によって美栖紙の表面に細かな穴があき,下層の裏打紙の繊維と絡まり合せることができる。と言われている。その状態を検証し,熟練度によって異なる接着促進の効果を確認するために,接着面の様子について走査型電子顕微鏡を用いて観察した。