There are a lot of human errors causing casualties at sea. We conducted ergonomic analysis of the casualty of Touya Maru, which is the worst fatal maritime casualty in Japan in 1945, the casualty of Yamato Maru in 1977, and two other cases. The accidents factor 4M (Man, Machine, Media, Management) was applied to analyze the accidents in the same methods as aircraft accidents investigation. We tried to extract some human factors by using "The human accidents investigation manual" of Japan Ergonomic society. From the result of this analysis, the Touya Maru accident occurred due to the captain's misjudgments, the delay of weather information and other factors, and the Yamato Maru case occurred due to the ambiguous operation rule in the typhoons, adding to the same factors of the Touya Maru case. If one of the accidents factors can be removed, the accidents might have been able to be prevented.

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1987 年から2013 年までの27 年間に渡り、東京都町田市、神奈川県横浜市青葉区、および川崎市麻生区にまたがる多摩丘陵南端の人工建築物で集団繁殖したチョウゲンボウのヒナについて、ヒナが巣立つ様子を調べた。さらに、人間に保護されたヒナをどのようにして放鳥すべきかについても調査した。結果は以下のように要約される。 1　巣立ちに適するヒナの大きさは、親鳥とほぼ同じ大きさである。 2　人工建築物に営巣した場合、人工建築物のパイプから外に出てくることが即ち、巣立ちであるとみなすことができた。 3　巣立ちの時期は、27 年間平均で6 月24 日前後で、時間帯は午前中の8:30 から10:00 に集中し、午後には認められなかった。 4　27 年間を通して、巣立ち日の約7 日前になると、親鳥はヒナに対して給餌行動をやめた。 5　人工建築物のパイプから出たヒナは30 分程度で飛翔して上空を舞う個体と、降下して一旦、木々の茂みに身を隠す個体があった。 6　巣立ったものの、飛翔力にやや欠けるヒナは、降下して植木の間に身を隠し最低3 日間は親鳥から給餌を受けた。 7　「やむを得ない事情」により、人間に保護されたヒナは、軍手やゴム手袋を着用し、段ボール箱の上蓋を閉めて落ち着かせてから、保護された地点に持って行って放鳥するのが望ましい。 8　チョウゲンボウのヒナが巣立つ条件として、営巣場所の前面が開けていることが必要である。このことはチョウゲンボウの繁殖場所を決める要因になると推察される。

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The story of Japanese tennis great Zenzo Shimizu's commendable behavior on the tennis court at the 1921 Davis Cup has been handed down to generations of Japanese school children. During a close championship match against an American team featuring tennis star Bill Tilden, Shimizu made a soft return of one of Tilden's shots because Tilden had slipped after making the shot. From this incident, Shimizu has been praised highly for his sportsmanship. The story was told in Japanese middle school textbooks before World War II and was adopted after the war for elementary school textbooks until the 1950's. However, an author began to doubt the truthfulness of the episode involving the two tennis legends, and there suddenly arose debate over whether or not the incident really happened. This study considers the authenticity of the event, focusing on Kaneji Yajima, who was the author that wrote the original account. The conclusion is summarized as follows: 1) Many of the accounts included in school textbooks had deviated from the writer's intension as they were handed down from textbook to textbook. Various adaptations were published by authors and editors who lost focus of the facts in relaying the moving events of the story. 2) In the post-war adaptations of the episode, the event occurred at the 1920 Wimbledon Tennis Championships rather than at the 1921 Davis Cup. In fact, a book was found which shows that Tilden slipped while playing against Shimizu during their 1920 match at Wimbledon. 3) Kaneji Yajima wrote his story in order to emphasize the instructive potential that sports has to offer. This study considers that Yajima created the inspirational story knowing full well that Tilden never slipped during the Davis Cup match. Yajima wanted to express an educational viewpoint that it is not good to stick to the extreme principle of competition and victory. The international event and Shimizu's fabled behavior embodied Yajima's ideal of athleticism and sportsmanship. A few historical facts about the incident have been successfully probed for accuracy, but there remains much conjecture and interpretation in this study. The matter calls for further investigation.

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　隣家の様々な騒音,近所の飲食店で発生する夜間の営業音,道路上等での作業の振動等都市住宅地で住民が感じる生活上の迷惑・被害は多様である。また近年の住宅地の過密化,人口集中が人間関係を複雑にし,迷惑・被害に対する自主的解決,行政による処置を困難にしていると考えられる。　本論文の目的はこうした都市生活型公害の実態を総合的に調査し,迷惑・被害の内容の構造を客観的なデータ解析を通して明らかにすることである。具体的な調査対象としては東京都の住宅地である世田谷区の公害対策課(当時)に申し立てられた公害苦情を扱う。調査の方法は区役所に苦情申し立てを行った住民に対して改めて調査票を郵送し,受けている迷惑・被害を詳細に記述してもらう方法を採用した。こうして得られた自由記述文に対するデータ解析では,文章に現れる頻度の高い単語に着目して2元クラスター分析を行う。この解析法では回答者の単語の記述パターンから単語同士,回答者同士の関連性を定める類似度を定義し,単語,回答者のそれぞれの集合のクラスター分析を行う。　単語の記述頻度を調べた結果,「音」,「騒音」の頻度が他の語に比べて非常に高く音に関連する苦情が特に多いことがわかった。2元クラスター分析結果の考察のために記述密度の概念を導入した。そして回答者全体を共通の認識を持つと考えられるグループに分類し,それらの特徴を明らかにした。具体的には営業音,作業音,悪臭をそれぞれ共通して訴えているグループが存在した。また迷惑・被害に対する対応に関して共通の認識を持っているグループも得られた。行政指導を特に訴えているグループ,地域の問題として捉えているグループが代表的である。　迷惑・被害の構造を客観的なデータ解析をとおして把握しておくことは,問題の解決や改善策を考える上で有効な指針になるものと考えられる。

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In this study, the meteorological knowledge necessary for deciding the operation of a ship was examined from the marine accident survey and the previous studies. By the comparison with the mariner examination, we considered the meteorological education that mariners should newly acquire to prevent marine accidents. In the marine accidents, some were caused by phenomena on the mesoscale γ to β and some were caused by mariners’ misinterpretation of meteorological information. On the other hand, in the mariner examination, most of the questions were on the synoptic scale, and also there were no questions about the latest weather forecasting technology such as satellite images and numerical weather prediction. Based on the above results, it was concluded that maritime officer needs the knowledge of the latest meteorological observation and forecasting technology as well as the uncertainty of meteorological information based on numerical weather prediction models.

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The purpose of this paper is to examine the impact of technical innovation on marketing channels and the Yamaha Music School under the mature Japanese piano market since the 1980s. The dilemma of the piano industry (e.g., the low diffusion rate, about 25%) drastically changed due to digital technology. In this new competitive environment, Yamaha carried out the three strategic changes: releasing low cost digital instruments, recasting sales channels, and reconsidering the Yamaha Music School's management policy.
In the early 1980s, newcomer Casio began producing and selling the Casiotone, a low cost digital instrument. Although Yamaha did not want to release cheap keyboard instruments which might decrease the demand for their leading products (the piano and electronic organ), in the late 1980s they launched Portasound (a Yamaha-made cheap keyboard) to compete against the Casio product. Moreover, Yamaha distributed this new product through the same mass retailers which dealt in Casiotones. Recasting their sales channel this way caused the old channel, the traditional exclusive distributor system, to struggle. However, it was important for Yamaha to maintain the traditional system, because exclusive distributors were skillful at selling expensive goods (pianos etc.) through consulting sales. Therefore, Yamaha reinforced the exclusive distributors by changing their form of profit-earning music schools from one in which the schools supported Yamaha through sales, to one in which Yamaha supported the schools through licensing. These schools became an important source of income in the face of reduced piano demand from 1980.
Yamaha maintained their position as market leader through these three strategic changes in spite of the technological paradigm shift in which they lost the first mover advantage. Although the double structure of their sales channel (comprising exclusive distributors and mass retailers) resulted in lower sales capacity for their exclusive distributors, the exclusive distributors were able to change their primary focus to the music education business. Yamaha's unique sales channel, with educational facilities, continues to transform while developing new keyboard instrument businesses.

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