As fundamental research of the operation of autonomous ships on the monitoring screen on shore, this paper focused on the differences in collision avoidance judgments based on various information sources, specifically via radar and via visual confirmation. Experiments were carried out using a ship-handling simulator with 14 seafarer trainees who had acquired the same level of maritime knowledge but had no actual experience at sea. Two experiments were carried out: a simple situation with one target ship appearing, and a complex situation where several targets appeared. The judgments in the complex situation showed that radar decision timing was quicker than visual decision timing. On the other hand, the simple situation showed no difference in course alteration and timing. Further results indicated that evaluation of the involved ships in the situation and the back ground of judgments varied depending on information sources. It is suggested that evaluation of the involved ships and the back ground of judgments may lead to differences in collision avoidance judgments. 本研究では，画面上に表示された情報による遠隔操船を考えるための基礎的研究として，操船シミュレー タを用い，目視情報のみを使用し衝突回避判断を行う実験と，計器情報(レーダー)のみを使用し衝突回避 判断を行う実験を，出現する隻数の異なる2種類の交通流で実施し，情報源の違いによる衝突回避判断に関 して検討を行った．実験参加者は，知識はあるが実航海での経験がない14名であった．衝突回避判断および 衝突回避判断に関わる事項を調査分析した．その結果，他船が一隻の状況では衝突回避判断に差がないが， 他船が複数隻存在する状況では，計器情報の方が早めに衝突回避を行うことが示された．このことは，衝突 回避判断に関わる事項( 「関心を抱く船」 ， 「衝突回避判断の背景」 )において，情報源間で差異が生じている ためと考えられた． (キーワード：情報源，衝突回避，レーダー，判断，遠隔操船)1 受付：2016年7月18日 受理：2017年10月24日

The trafflc condition in thc Strait of Istanbul has navigational diHiculties because of the geographicaI restriction and the traf 五c congestion ． The recent statistics dicate that皿 価 皿 e traff7ic has been increasing and volume of tanker tra 岱 c is anticipated becoming double in coming year and 重 riple by 2010 due to the increase of transportation of the Caspian O 且． On lhe olher hand ， 出e navigational rule in 血 e Strait of IstanbUl has been changed twice in 1982 and l994 to prove 血 e naVigational safety ． So that ， the重 erms fer 旧1ysis were divided 血to 血 ee periods ； from 1965 tO 1982 ， 丘om 1982 to 1994 and 仕 om l994 to present ． Marine accidents oceurred in tho strait were analyzed fbr three pariodS ． The inerease of 出 e marine accidentS occurred in the strait was arkable 洫 spite ofthe 血 provement ofnaVigational rule in the strait ．

It is an important step to read draughts accurately in the process of draught surveys because inaccurate one could lead to a cause of disputes between all the interested parties. The draught reading is conducted by ship's officers or professional surveyors based on their visual observation even today. Therefore, there are some difficulties in keeping an accurate measurement or observer's safety under unfavorable conditions such as bad weather, strong swell and so forth. In this paper, the authors propose a novel draught reading method using image processing for supporting reading draughts. The method comprises some processing steps, detecting draught marks, stabilizing the hull motion and recognizing draught marks by template matching, and detecting waterline due to accumulated sequential inter-frame differences. Experimental results show that the proposed method attained high precision of the measurement.

The length of experience as a navigator ， such as year or a month ， is one of irnportant factors 洫 co ｝ lision judgments ． ln addition ， eollision investigations indicate that experience with ships ofa specific type， such as specific ship ' slength or specl 丘c gross to age ， is also import 跏 t． In this study ， we 飴 cused on experience with ships ofa specific type and investig 前 ed the thne ofaction taken basgd on sea experience us 血 g a questio ahe in several navigationa 韮situations involving a risk of collision ． The results indicated the fblIowing ． N 工 工 一 Eleotronio Library