Directory of Researchers

SERA Wataru
Graduate School of Maritime Sciences / Department of Maritime Sciences
Associate Professor
Mercantile Marine Science
Last Updated :2023/01/12

Researcher Profile and Settings

Affiliation

  • <Faculty / Graduate School / Others>

    Graduate School of Maritime Sciences / Department of Maritime Sciences
  • <Related Faculty / Graduate School / Others>

    Faculty of Oceanology / Department of Oceanology, Faculty of Maritime Sciences / Department of Global Transportation Sciences

Teaching

Research Activities

Published Papers

  • Akihiko Matsuda, Hirotada Hashimoto, Yuuki Taniguchi, Daisuke Terada, Jun Miyoshi, Hiroyasu Mizoguchi, Katsuo Hasegawa, Wataru Sera

    Advanced Marine Science and Technology Society, Jul. 2017, Journal of Advanced Marine Science and Technology Society, 23 (1), 47 - 51, Japanese

    [Refereed]

    Scientific journal

  • Validation of a Ship Collision Avoidance Algorithm in Congested Sea Area by Means of Model Experiment

    Yuuki Taniguchi, Akihiko Matsuda, Wataru Sera, Daisuke Terada, Hirotada Hashimoto

    The Japan Society of Naval Architects and Ocean Engineers, Nov. 2016, Conference Proceedings of The Japan Society of Naval Architects and Ocean Engineers Japan, (23), 627 - 632, Japanese

    Symposium

  • A Study of Anchor Chain Model to Evaluate Behavior of Moored Ships under Tsunami Attack

    米田 翔太, KOBAYASHI EI-ICHI, SERA Wataru, 越村 俊一, 白川 裕太

    2011 年 3 月 11 日には東北宮城沖を震源とした東北地
    方太平洋沖地震により、それに伴う巨大津波によって大
    きな被害が出た。
    船舶については東日本大震災では緊急離桟によって船
    舶が津波の被害から逃れることに成功した事例が報告さ
    れている。このように、船舶に対しても津波来襲時のマニ
    ュアルの作成が重要であると言える。ここで、沖合を航行
    中の船舶に対しては「漂泊」と「錨泊」の二つのシナリオ
    が考えられる。
    従来から、強風中の船舶の触れ回りなどの現象を解析
    するために、錨及び錨鎖に対するさまざまなモデル化 1,2)
    が行われてきた。これらの検討の前提は、風や潮流といっ
    た外力の向きに対して、錨から船舶までが一直線に並ん
    でいる状態としている。これは、風や潮流といった外力は
    その力の方向や大きさの変化が非常に遅いため、錨泊船
    舶の初期状態がどのような

    The Japan Society of Naval Archtects and Ocean Enginners, Nov. 2014, Conference Proceedings, the Japan Society of Naval Architects and Ocean Engineers, (第19号), 563 - 565, Japanese

    Scientific journal

  • Research on position keeping vessels under the new assumed tsunami attack in Osaka Bay

    KOBAYASHI EI-ICHI, 川 端 拓郎, SERA Wataru, 越村 俊一

    今後 30 年以内に 70%程度の確率で発生すると言われ
    ている南海東南海地震 1)は、これまでにも津波を発生させ
    ており、次回発生の際においても断層の真北に位置する
    大阪湾に津波が押し寄せてくることが容易に想定できる。
    2011 年に発生した東日本大震災の際には津波による船
    舶の乗り上げ、衝突、転覆などの被害が多数発生した。
    それらを防ぐための港外避難とその経路や錨泊について
    は、村山ら 2)により研究が着手されている。しかし、水深
    が深い状況や津波来襲までの時間的制約のある船につい
    ては錨を使用せずに津波をやり過ごす必要がある。操船
    者が執りうる手段として、津波に対抗しながらある範囲
    内に留まる漂泊操船を行うと考えられる。さらにその漂
    泊操船については現在ほとんど研究されていない。その
    ため、錨泊地まで比較的距離のある船舶の津波対策はこ
    れまでで

    The Japan Society of Naval Archtects and Ocean Enginners, Oct. 2014, Journal of the Japan Society of Naval Architects and Ocean Engineers, (第19号), 561 - 562, Japanese

    Scientific journal

  • 津波来襲時におけるポッド推進船の緊急離岸操船に関する研究

    KOBAYASHI EI-ICHI, SERA Wataru, 志知 翔太, 川端 拓郎

    津波による客船の被害を防ぐには,既成的事例が少なく多面的な対策が急務である.本研究では,津波来
    襲時における,ポッド推進器を搭載した大型客船の出港シミュレーションを行った.本研究のシミュレーシ
    ョン状況下では,津波による大きな影響が生まれる前に,単独で出港することができた.さらに,本研究で
    使用したシミュレーションは,船舶のデータや気象海象のパラメータを変更できるため,様々な条件下での
    シミュレーションが可能である.

    Sep. 2014, 日本航海学会講演予稿集, 2巻 (2号), 96 - 99, Japanese

    Scientific journal

  • A Study of Safety Measures for Fishing Boat at Osaka Bay

    HIGASHINO Tomoki, USUI Hideo, SAKAIDE Masatoshi, SERA Wataru

    Nov. 2013, The Proceedings of Asia Navigation Conference 2013, English

    [Refereed]

    International conference proceedings

  • Berthing assessment for cruise ship with pod propulsion system

    KOBAYASHI Ei-ichi, SERA Wataru, ASAJIMA Takashi, HOURI Jou

    Oct. 2013, The Proceedings of 21st International Maritime Lecturers Association Conference, 59 - 67, English

    International conference proceedings

  • ポッド推進船の出入港時の操船安全性評価に関する研究

    Takashi Asajima, Ei-ichi Kobayashi, SERA Wataru

    日本船舶海洋工学会, May 2013, 日本船舶海洋工学会講演会論文集, (第16号), Japanese

    Symposium

  • 山崎 慎也, 増田 憲司, SERA Wataru

    The act on Partial Revision of the Act on Port Regulations and the Maritime Traffic Safety Act was enforced on July 2010. It follows on this law, a vessel shall not overtake other vessels in the designated section of the Kurushima Traffic Route. And when current is adverse, a vessel shall navigate with a log speed of 4 knots and upwards. However, the congestion has occurred within the traffic route by no passing. This situation has given to navigation officer load, and the dangerous situation has occurred.
    How to solve this problem, the marine traffic control according to a situation is required. That is, passing of small vessel is made possible.
    Then, the questionnaire was carried out about the distance which navigation officer needs within the traffic route. From the result of the questionnaire, it was defined as Limit of Distance. And the new navigation control method was proposed.
    This research considered the safety navigation within the traffic route for a small vessel.

    日本航海学会, Mar. 2013, 日本航海学会論文集, 128 (128), 9 - 14, Japanese

    [Refereed]

    Scientific journal

  • A Study of Hanshin Port as International Container Strategy Port from the Viewpoint of Kitakyushu Area

    USUI Hideo, SERA Wataru, INADA Yuichiro

    Nov. 2012, The Proceedings of Asia Navigation Conference 2012 Kobe, 1 - 6, English

    [Refereed]

    International conference proceedings

  • ドッグマスターの現状と今後のあり方について

    USUI HIDEO, SERA Wataru, 星野 伸行

    日本航海学会, Sep. 2012, 日本航海学会論文集, (127), 117 - 123, Japanese

    [Refereed]

    Scientific journal

  • SHINOZAKI Keiji, USUI Hideo, SERA Wataru, INOUE Kinzo

    It is very important to know which ship is dangerous in congested situation for mariners. Even though the functions for avoiding ship collision on ARPA have continuously improved, marine accidents continue to occur. In this research,we developed a new system named "Predicted ES Monitor" which is based on the Enviornmental Stress Model. The monitor indicates the difficulties of ship handling in the near future and the situation around own ship. With it the mariner can decide their own ship's route according to the information. We compared the effectiveness of Predicted ES monitor with ARPA by the using a ship handling simulator. The results of our experiment showed that the group using ARPA measured 750 or more on the ES value. This is not acceptable for mariners. However, the group using the monitor did not exceed 750. Therefore the informative support given by the monitor was better, when compared with the ARPA. In conclusion, it was able to be shown that indicating the difficulties of ship handling in the near future and the situation around own ship was effective for mariner's collision avoiding action.

    日本航海学会, Mar. 2010, 日本航海学会論文集, 122 (122), 155 - 162, Japanese

    Scientific journal

  • 齊藤望, SERA Wataru

    In Japan, there are provided tug requirements in each compulsory pilot district. However, most of the requirements only show the number of required tugs but not showing how to determine the numbers. Therefore, the conflict, which is about the requirements of tug numbers, occurs between captain and pilot sometimes. The purpose of the study is to find a method of making the practical tug requirements particularly in Kobe area and Osaka area of Hanshin Port. First, we researched the tug requirements which are used in Kobe area and Osaka area to clear the present condition of the requirements. Second, we calculated the output of required tugs by using the external force calculation. Then, we compared the current requirements with the results of the external force calculation. According to the results of the comparison, we found that the current tug requirements for Kobe area and Osaka area of Hanshin Port are applied to the condition when wind blew less than 8m/sec. Finally, we made the method of making the tug requirements using the external force calculation.

    日本航海学会, Mar. 2010, 日本航海学会論文集, 122 (122), 179 - 184, Japanese

    [Refereed]

    Scientific journal

  • 酒出昌寿, SERA Wataru, 井上 欣三, 本村 紘治郎

    The bisan-seto sea area in the Inland sea of Japan is not only a marine traffic congested area but a good fishing area. Stownet fishing boats which operate fishing actively conflict with ships in the bisan-seto sea area. It is necessary that quantitative evaluation of the ship's maneuvering difficulty and also the stownet fishing boat's fishing operation difficulty for relaxation of conflict between stownet fishing boats and ships. On the basis of the above consideration, we made inquiries to stownet fishermen about minimum passing distance between stownet fishing boat and ship, and then found that can be closely resembled by regression lines through the regression analysis. As the result of the investigation, we proposed models of stownet fisherman's senses on passing distance between stownet fishing boat and ships which are resembled by regression lines through the regression analysis.

    日本航海学会, Mar. 2010, 日本航海学会論文集, 122 (122), 139 - 148, Japanese

    [Refereed]

    Scientific journal

  • New Method for Teaching Tugboat Operations Linked to a Ship-handling Simulator

    Hideo USUI, Wataru SERA

    Nov. 2009, The Proceedings of Asia Navigation Conference 2009, 348-353, English

    [Refereed]

    Scientific journal

  • Effectiveness of Estimated Environmental Stress Value Monitor

    Hideo USUI, Keiji SHINOZAKI, Wataru SERA

    Oct. 2009, The Proceedings of 13th IAIN World Congress, English

    [Refereed]

    Scientific journal

  • Traffic Control using AIS in Japan

    SERA Wataru

    Apr. 2009, Proceedings of the 9th Japan/Korea Joint Seminar, English

    Symposium

  • 酒出昌寿, SERA Wataru, 井上 欣三, 本村 紘治郎

    The bisan-seto sea area is not only an important marine transportation hub but also a good fishing ground. The stownet fishery is operated energetically in the bisan-seto sea area. Its main fishing grounds conflict with legal traffic routes. Ship's operators and fishermen have discussed this conflict problem, still they don't have sufficient solution yet. It is necessary for sufficient solution of this conflict problem to approach this problem by a new investigation method. In this study, we have researched their conflict condition. And also, we have examined evaluating the difficulty of ship-handling by avoiding stownet fishing boats and the difficulty of operating stownet fishery in the legal traffic routes through the environmental stress model. Then, we have discussed possibility of evaluating them by the environmental stress model.

    日本航海学会, Sep. 2008, 日本航海学会論文集, 119 (119), 51 - 58, Japanese

    [Refereed]

    Scientific journal

  • Xianghui XING, Kinzo INOUE, Hideo USUI, Wataru SERA

    There are many of straits and channels near the Japanese coast. Navigating at these kinds of restricted and congested water-areas, it is more difficult for mariners to handle the ship at nighttime than at daytime. This research aims at studying on the reduction of ship-handling difficulty in the channel due to nighttime. In this paper, on the base of our past study on the difference of mariner's perception of safety (when approaching to a shore and encountering with other ship) at daytime and nighttime, the nighttime version of Environmental Stress Model was made, and using this new model, the difficulty of ship handling at nighttime is evaluated quantitatively. In order to evaluate comparatively the ship-handling difficulty at daytime and nighttime in the straight channels with different width, the marine traffic simulation was carried out. About the simulation, two kinds of traffic flow were considered: one-way and two-way. Based on the result of simulation, the ship-handling difficulty at daytime and nighttime was calculated, and the measures to reduce the ship-handling difficulty at nighttime was analyzed from the aspects of 1) Slowdown, 2) Reduce the congestion of marine traffic, 3) Extend the width of channel.

    Japan Institute of Navigation, Sep. 2008, The Journal of Japan Institute of Navigation, 119,59-65, 59 - 65, Japanese

    [Refereed]

    Scientific journal

  • Experimental Study on Braking Force Characteristics of Tugboats in Shallow Water

    YANG L, Lee S.S, INOUE Kinzo, SADAKANE Hiroyuki, SERA Wataru

    Jul. 2008, The Proceedings of the Eighteenth (2008) International Offshore (Ocean) and Polar Engineering Conference, 3, 636 - 643, English

    [Refereed]

    International conference proceedings

  • 高橋 浩子, 井上 欣三, SERA Wataru

    Unsafe Ship-handling model (US-model) is known as an evaluation method, which analyzes the potential risk of marine accidents. In previous paper, this conventional model was improved for evaluating small obstacles such as the bridge pier. In this time, we aim to improve the conventional model to be able to evaluate the occurrence of unsafe situation for the collision risk against ships definitely. In ship-handling simulator, several traffic situations were set. From the experience's results, we cleared that following 2 points. - (1) In case of that one ship's size and crossing angle were changed, if the crossing angle was 135 degree and ship size became less than 80m, the gap of calculation's results between conventional model and improved model much occurred. - (2) In case of that all ship size were changed parametrically, if the ship size became less than 80m, the gap of calculation's results much occurred too. It shows it comes to application limit of conventional model, and to application area of improved model. In this experiment, this gap makes the precision difference of marine accidents ratio in 1.9×10^<-5>〜10^<-6>. But calculation time of improved model is very much than conventional one. So, it is necessary to decide an application of improved model by choosing a precision or calculation's time.

    日本航海学会, Mar. 2008, 日本航海学会論文集, 118 (118), 23 - 29, Japanese

    [Refereed]

    Scientific journal

  • Outline of the ship to shore liaison support system

    SERA Wataru

    Oct. 2007, The Proceedings of Taiwan-Japan International Seminar on Ship Utilization in Emergency Medical Activities, English

    [Invited]

    Symposium

  • Xianghui XING, Kinzo INOUE, Hideo USUI, Wataru SERA

    In recent years, navigation at nighttime is increasing by deregulation of night entry-into-port restrictions inside ports and harbors. In order to ensure the safety of navigation in those areas, the evaluation based on mariners' perception of safety is needed. In this research, a quantitative expression model of the mariners' perception of safety when approaching toward a shore is proposed to show the difference between at daytime and nighttime, by carrying out ship handling simulator oriented experiments. The data about the perception of safety at daytime and nighttime obtained through the ship handling simulator experiments were analyzed, and it became clear that the mariners' perception of safety at daytime and nighttime has a difference. Moreover, the individual difference about perception of safety of risk averse or risk acceptance was considered in the model.

    Japan Institute of Navigation, Sep. 2007, The Journal of Japan Institute of Navigation, 117,191-197, 191 - 197, Japanese

    [Refereed]

    Scientific journal

  • 高橋 浩子, 井上 欣三, SERA Wataru

    Unsafe Ship-handling model (US-model) is known as an evaluation method which analyzes the potential risk of marine accidents. In previous paper, this model was improved for evaluating small obstacles, definitely. This research aims to evaluate the influence of the pier arrangement by applying the improved US-model to the bridge design on a straight channel and a curved channel. In ship-handling simulator, a bridge with the various pier-pier distances was set on the straight channel. The potential collision risk to the pier decreases when the pier-pier distance is wide enough, such as 2000m by the experiment results. In the traffic simulation, pier-pier distances, pier arrangement types and curved angles were set on the curved channel. The potential collision risk extremely increases at the following conditions. (1) The pier-pier distance is less than 1500m. (2) The curved angle becomes severe at the pier-pier distance is 1000m. (3) The arranged pair of pier is set on the backward side from the curved corner. In conclusion, it can be said that the improved US-model could evaluate the influence of the pier arrangement on a straight and a curved channel clearly.

    日本航海学会, Sep. 2007, 日本航海学会論文集, 117 (117), 97 - 104, Japanese

    [Refereed]

    Scientific journal

  • 成 兪昶, 井上 欣三, SERA Wataru

    Recently, environmental stress in port area strengthens with traffic volume increasing. In addition, the available route-width becomes narrow because of the enlargement and the specialization of vessel relatively. Therefore, it's necessary to access the route-width in the view not only of a ship motion but also of traffic congestion. The design method on route-width focuses on the maneuvering of a maximum size ship now. But, this method is not clear on safety because a lot of various vessels exist and pass in same route. To solve this problem, we suggested in the former report how to determine the route-width in consideration of traffic volume near shore. In this research, we set the traffic volume and speed in harbour and carried out simulation in one-way and two-way route. The results showed as relation between route-width and traffic volume. And these lead us to estimate the route-width including the effect of traffic congestion.

    日本航海学会, Sep. 2007, 日本航海学会論文集, 117 (117), 91 - 96, Japanese

    [Refereed]

    Scientific journal

  • 酒出昌寿, SERA Wataru, 井上 欣三, 本村 紘治郎

    The Bisan-seto Sea Area is not only important marine transportation hub but also good fishing ground and marine recreational area. Recently, any vessels and boats compete with other vessels and boats, therefore, this situation is composed of congested traffic environment in this sea area. According to the past research, the Bisan-seto Sea Area had the most marine accidents in main 20 narrow channels of Japan. In this study, we tried to research and analyze their marine accidents based all marine accident data of Japan Coast Guard from 1996 to 2005, and we had their basic analysis results that it was necessary for promotion of safety marine traffic, safety fishing, and cooperative coexistence of competing vessels and boats.

    日本航海学会, Mar. 2007, 日本航海学会論文集, 116 (116), 83 - 90, Japanese

    [Refereed]

    Scientific journal

  • 高橋 浩子, 井上 欣三, SERA Wataru

    Unsafe Ship-handling model (US-model) is known as the evaluation tool suggests the potential risk of marine accidents. Conventional US-model such as the above, however, has error for its discrete processing when it evaluates the small obstacle such as the buoy or the bridge pier. In this paper, we aims to improve the conventional US-model that treated the judgment element as the disintegration value to be able to judge about the progress of continues time and evaluate the influence for the occurrence of unsafe situation for small obstacles such as the bridge pier or the buoy definitely. In ship-handling simulator, we set the experiment sea area that has the bridge which has various pier to pier distance and 80m pier diameter. From the data of experience result, we compared an output result by conventional US-model and by improved US- model when the size of pier diameter was changed. From the above, we cleared that if the obstacle became less than 80m, the gap of calculation results between conventional and improved model was occurred, and it comes to application limit of conventional model, and to application area of improved model. In addition, the tendency of calculation results according to various pier to pier distances and the size of pier diameter by improved model showed the utility. In conclusion, it may be said that improved model can evaluate influence for danger of collisions for a small obstacle such as the pier or the buoy, correctly.

    日本航海学会, Mar. 2007, 日本航海学会論文集, 116 (116), 17 - 23, Japanese

    [Refereed]

    Scientific journal

  • 交通量を考慮した航路幅の決定について

    成 兪昶, 井上 欣三, SERA Wataru

    日本航海学会, Mar. 2007, 日本航海学会論文集, (116), 25 - 30, Japanese

    [Refereed]

    Scientific journal

  • Kenji MASUDA, Kinzo INOUE, Kouhei HIRONO, Wataru SERA

    In recent years, the huge bridge has been built in the congested straits or channel. The Marine Traffic Safety Law set up the Traffic Route in the narrow channel. The Traffic Route fixed a marine traffic. The bridge pier is necessary for huge bridge. And that was built in strait or channel. But the bridge pier has been arranged out of the Traffic Route. As for the construction plan of a future bridge, a place without a route. In this research, we attend to difficulty of ship handling and what kind of influence arrangement of a bridge pier gives difficulty of ship handling quantitatively. And we evaluated it for a design of navigation space of a ship and examined using by Routing Model and ES model.

    Japan Institute of Navigation, Sep. 2006, The Journal of Japan Institute of Navigation, 115,39-43, 39 - 43, Japanese

    [Refereed]

    Scientific journal

  • 潜在環境負荷と残存環境負荷の関係について-Ⅲ.-輻輳交通流における数量関係に関する検討-

    Honbin XIE, Kinzo INOUE, Hideo USUI, Wataru SERA

    Mar. 2006, The Journal of Japan Institute of Navigation, 114号 pp.59-64, Japanese

    [Refereed]

    Scientific journal

  • HIRONO Kohei, SERA Wataru, FUCHI Masaki, INOUE Kinzo

    SHIN NIHON KENTEI KYOKAI (New Japan Surveyors & Sworn Measurers Association that is abbreviated as "SK") has developed the device to support to read draft that is named "KENDRAFT" and operated it in the fields. To read draft is very important for the mercantile marine trading. However, it has not been improved to advance an accuracy, and still involved risky work. This paper describes the result of experiments to clarify the principal and performance of the KENDRAFT. And its purpose is to contribute toward increasing fairness and safety at draft reading.

    日本航海学会, Mar. 2006, 日本航海学会論文集, 114 (114), 165 - 170, Japanese

    [Refereed]

    Scientific journal

  • Development of a Simple Technique to Predict Ship Response in a Seaway

    SERA Wataru, Duffy Jonathan T, SMITH Ian, XIA Jinzhu

    Feb. 2006, The Proceedings of Pacific 2006 International Maritime Conference, Sydney, 375 - 383, English

    [Refereed]

    International conference proceedings

  • A ship monitoring system using a communication satelite for maritime safety

    Kinzo INOUE, Hideo USUI, kouhei HIRONO, Wataru SERA

    Oct. 2005, Maritime Security and MET,proceeding of the 6th IAMU conference, pp205-214, English

    Scientific journal

  • 潜在環境負荷と残存環境負荷の関係について-Ⅱ-交差航路における数量関係に関する検討-

    Honbin XIE, Kinzo INOUE, Hideo USUI, Wataru SERA

    Sep. 2005, The Journal of Japan Institute of Navigation, 113号 pp.31-36, Japanese

    [Refereed]

    Scientific journal

  • 架橋下通航における操船者の行動に関する研究-Ⅱ.-操船行動モデルの汎用化-

    Kenji MASUDA, Kinzo INOUE, Hideo USUI, Kouhei HIRONO, Wataru SERA

    Sep. 2005, The Journal of Japan Institute of Navigation, 113号 pp.53-58, Japanese

    [Refereed]

    Scientific journal

  • 安全性とヒューマンファクターの関係に基盤をおいた陸上からの船舶安全管理

    井上 欣三, HIRONO KOHEI, USUI HIDEO, SERA Wataru

    日本航海学会, Dec. 2004, 日本航海学会誌 Navigation, (161), 71 - 77, Japanese

    [Refereed]

    Research society

  • Hideo USUI, Kinzo INOUE, Masanori TSUGANE, Kouhei HIRONO, Wataru SERA

    When VTS (Vessel Traffic Service) is applied in a narrow and congested water area of Japan, VTS operators are in charge of recognizing, using RADAR and ARPA, the motions of ships in the covered area and of giving safety information to officers on board. At present, they cannot actively order ships in the area how to maneuver to avoid collision or grounding. In the near future, we believe that VTS operators will be able to judge the possibility of collision or grounding, and to instruct officers on board to take concrete actions. At that time, it will be necessary to harmonize a sense of safety between ships' officers and VTS operators. In this paper, a 3-dimensional viewing system to show the situation of a ship in a water area is proposed to share the situation of awareness between ships' officers and VTS operators. The effectiveness of this system is verified by the experiment using the training ship "Fukae-maru".

    Japan Institute of Navigation, Sep. 2004, The Journal of Japan Institute of Navigation, 第111号 pp.113-118, 113 - 118, Japanese

    [Refereed]

    Scientific journal

  • 増田 憲司, 井上 欣三, USUI HIDEO, HIRONO KOHEI, SERA Wataru

    In the congested strait, Traffic route is set up by the Marine Safety Law and other regulations. As for the vessel traffic way, rectification is done by this law. But, the navigation route is restricted. In this area, very large bridge was built. And various arguments had been done about the influence of the pier in the strait by now. As a result, it was arranged outside of Traffic route. And not obstructing the navigation of the vessel is being considered with the pier. On the other hand, bridge construction is planned in the future program for land development by a strait such as Tomogashima channel, Bungo channel, too. In those area is no regulation by the route. Therefore, the existence of the pier becomes an obstacle in navigation because a very large bridge is built in the channel which a vessel navigated freely now. In this research, questionnaire investigation was done for pilots and captain. And research of the behavior consciousness about the route select by the navigation officer in the strait which a pier exists in. It is tried to modeling that how routing by officer though the analysis of the questionnaire

    日本航海学会, Sep. 2004, 日本航海学会論文集, 111 (111), 97 - 102, Japanese

    [Refereed]

    Scientific journal

  • INOUE Kinzo, MASUDA Kenji, SETA Hiroaki, KAWASE Masayuki, PARK Yong-Soo, YASUDA Masaru, HARA Daichi, USUI Hideo, HIRONO Kouhei, SERA Wataru

    Safety evaluations of ship handling are in fact dependent on subjectivity due to the imperfect objective index used for evaluating the results of experiments using a ship-handling simulator. In the present paper, a safety evaluation index that objectively determines the quantitative risks of collision and stranding when the experiment is executed using a ship-handling simulator is proposed, by noting Unsafe Ship Handling Situations. An Unsafe Ship Handling Situation is defined as a condition in which the risk becomes obvious in the near future by maintaining the present maneuvering condition unaltered in spite of an accident not having occurred. It can be determined, in each time section, in terms of whether or not the Time To Collision (TTC) exceeds the Short Stopping Time (SST) under the corresponding speed. According to the Heinrich's Law, an Unsafe Ship Handling Situation corresponds to the detection of some several thousand hidden unsafe situations behind one obvious case of an accident. The appearance ratio of the proposed Unsafe Ship Handling Situation and the accident ratio in the corresponding sea area coincide with the order of 10^<-3>. This means that, by deriving the number of Unsafe Ship Handling Situations from a series of ship handling processes, the underlying accident risk in the process of ship handling may be estimated from the relation with this ratio of 10^<-3>. The proposed safety evaluation index for Unsafe Ship Handling Situations is considered to be an objective index that is unbiased towards subjectivity, and to contribute to maintaining the universality of the results on a reasonable probabilistic basis.

    THE JAPAN SOCIETY OF NAVAL ARCHITECTS AND OCEAN ENGINEERS, 2004, Journal of the Kansai Society of Naval Architects, Japan, 2004 (241), 205 - 210, Japanese

    [Refereed]

    Scientific journal

  • A Method of Quantitatively Evaluating the Effectiveness of Safety Improvement of Navigation Condition

    INOUE Kinzo, YURTOREN Cemil, SERA Wataru, USUI Hideo, HIRONO Kohei

    Oct. 2003, The Proceedings of International Association of Institute of Navigation, World Congress-11, English

    [Refereed]

    International conference proceedings

  • 操船シュミレータ訓練における避航操船のスキル向上に関する客観的評価法

    井上 欣三, 馬 蓉, 臼井 英夫, 世良 亘

    Sep. 2003, 日本航海学会論文集, 第109号,pp.209-216, Japanese

    [Refereed]

    Scientific journal

  • 出入港操船の危険度評価と操船支援情報の効果

    瀬田 広明, 井上 欣三, 世良 亘, 広野 康平

    Sep. 2003, 日本航海学会論文集, 第109号,pp.63-68, Japanese

    [Refereed]

    Scientific journal

  • 津金 正典, 井上 欣三, HIRONO KOHEI, SERA Wataru

    In heavy traffic water, captains navigate the water paying careful attention to traffic around own ships in order to avoid collision and grounding. Especially when visibility is very poor, they should briefly judge the situation of other ships observing only ARPA display. Therefore it is a heavy burden for them to observe ARPA display. It was examined that Collision Danger Line (CDL) information was very effective for captains to navigate in heavy traffic water on ship handling simulator experiments before. Experiments on providing CDL information for ship handler of an actual ship underway were carried out and effectiveness of CDL information was confirmed, and also improvement of display of CDL triangle was performed.

    日本航海学会, Sep. 2003, 日本航海学会論文集, 109 (109), 125 - 131, Japanese

    [Refereed]

    Scientific journal

  • SERA Wataru, 井上 欣三, 本村 紘治郎, 松田 秋彦

    Controllable Pitch Propeller (CPP) is very useful for avoiding collisions in a restricted area like harbour. Because the changing time of propeller pitch is shorter than changing time of engine motion, the ship with CPP can stop in quite short distance. So, full-scale experiments have been performed to investigate how to move the ships equipped with CPP under the Reverse Stopping on turning rate. The obtained results are summarized as follows : (1) The direction of moving is decided by the initial turning rate. (2) Head reach shows the maximum value near 0 degree of rudder angle and reduces when rudder angle increases. (3) The value and distribution of side reach are various about each ship.

    日本航海学会, Mar. 2003, 日本航海学会論文集, 108 (108), 219 - 224, Japanese

    [Refereed]

    Scientific journal

  • 井上 欣三, 馬 会, HIRONO KOHEI, SERA Wataru

    The measures based on IMO-conventions bring into play by the convention ratification as a result of the consensus of each nation. Therefore, the effect of the convention can be expected if more nations ratify it earlier. One of the measures to urge all nations cooperate actively toward the goal of the convention is to become able to predict quantitatively how much the decrease of marine casualty will be expected in the future by the implementation of the convention. If the effect can be predicted and can be announced it officially, the increase of nations to adopt the convention will be expected. Recently, the importance of the prior evaluation has been recognized, and the technique called Formal Safety Assessment (FSA) has been introduced in IMO. The basic concept of this technique is to guarantee the logical necessity to realize the concrete countermeasure based on the consensus among countries of the marine society. In the present paper, paying attention to correlation between promotion of convention and the casualty decrease, we tried to approach to the strategic designing of the ratification pace which leads to the goal of safety at sea before the new convention is carried out. The achievements in the present paper, which enable the future prediction of casualty decrease by the ratification of convention, have the prior evaluation based on FSA realize.

    日本航海学会, Mar. 2003, 日本航海学会論文集, 108 (108), 11 - 20, Japanese

    [Refereed]

    Scientific journal

  • SERA Wataru, 梅田直哉

    In order to investigate capsizing in quartering and following seas, numerical simulations of the rolling motion were systematically carried out for a container ship sailing in short-crested irregular waves, e.g., directional spectrum waves. The obtained results are summarized as follows : (1) Low cycle resonance occurs for a container ship even in short-crested irregular waves. (2) The heading angle from the wave principal direction reduces danger of ship capsizing. (3) The short-crestedness of waves also reduces danger.

    日本航海学会, Mar. 2001, 日本航海学会論文集, 104 (104), 141 - 146, Japanese

    [Refereed]

    Scientific journal

  • SERA Wataru, 梅田直哉

    For model experiments of nonlinear behaviors of a ship running in realistic ocean environment, it is necessary to generate short-crested irregular waves that have a specified and stationary directional spectrum in a model basin. However, the measurements of the waves generated by the double-summation method with side-wall reflections indicated that the variance of wave elevation is not stationary in space. Therefore, the authors carried out comprehensive numerical experiments to compare the double-summation method and single-summation one both with side-wall reflections. As a result, it is concluded that single-summation method even with side-wall reflections can be regarded as practically stationary in space but the double-summation method cannot.

    日本造船学会, Dec. 2000, 日本造船学会論文集, 188 (188), 251 - 256, Japanese

    [Refereed]

    Scientific journal

  • 電子メールを用いた海難救助・油防除に関する人的シミュレーション

    YANO YOSHIJI, FURUSHO Masao, SERA Wataru, 石田 憲治

    神戸商船大学, Jul. 2000, 神戸商船大学紀要 第二類 商船・理工学篇, 48 (48), 1 - 6, Japanese

    [Refereed]

    Research institution

  • 海上交通安全評価のための技術的ガイドライン策定に関する研究-Ⅳ. -ニアミス危険の定量化と評価の総合化への指針-

    井上 欣三, 増田 憲司, SERA Wataru, USUI HIDEO

    日本航海学会, Mar. 2000, 日本航海学会論文集, (102), 203 - 209, Japanese

    [Refereed]

    Scientific journal

  • 海上交通安全評価のための技術的ガイドライン策定に関する研究-Ⅱ. -潜在的操船水域の概念に基づく操船の安全性評価-

    井上 欣三, 増田 憲司, SERA Wataru

    日本航海学会, Sep. 1998, 日本航海学会論文集, (99), 163 - 171, Japanese

    [Refereed]

    Scientific journal

  • 海上交通安全評価のための技術的ガイドライン策定に関する研究-Ⅰ. -環境負荷の概念に基づく操船の困難性評価-

    井上 欣三, 増田 憲司, SERA Wataru

    日本航海学会, Mar. 1998, 日本航海学会論文集, (98), 225 - 234, Japanese

    [Refereed]

    Scientific journal

  • Model Experiments of Ship Capsize in Astern Seas - Second Report

    HAMAMOTO Masami, ENOMOTO Takashi, SERA Wataru, PANJAITAN James P, ITO Hiroto, TAKAISHI Yoshifumi, KAN Makoto, HARAGUCHI Tomihiro, FUJIWARA Toshihumi

    the Society of Naval Architects of Japan, Jun. 1996, Journal of the Society of Naval Architects of Japan, (179), 77 - 87, English

    [Refereed]

    Scientific journal

  • Capsize of Ship in Beam and Astern Sea Conditions

    HAMAMOTO Masami, SERA Wataru, PANJAITAN James P

    Osaka University, Apr. 1996, Technology Reports of the Osaka University, 46 (2243), 97 - 106, English

    [Refereed]

    Research institution

  • Analyses on Low Cycle Resonance of Ship in Irregular Astern Seas

    HAMAMOTO Masami, SERA Wataru, PANJAITAN James P

    the Society of Naval Architects of Japan, Dec. 1995, Journal of the Society of Naval Architects of Japan, (178), 137 - 145, English

    [Refereed]

    Scientific journal

  • Transverse Stability of Ships in Irregular Astern Seas

    HAMAMOTO Masami, SERA Wataru

    Sep. 1995, The Proceedings of 6th International Symposium on Practical Design of Ships and Mobile Units (PRADS'95), 1, 467 - 478, English

    [Refereed]

    International conference proceedings

  • Model Experiments of Ship Capsize in Astern Seas

    UMEDA Naoya, HAMAMOTO Masami, TAKAISHI Yoshifumi, CHIBA Yutaka, MATSUDA Akihiko, SERA Wataru, SUZUKI Shiro, SPYROU Konstantinos, WATANABE Kenji

    the Society of Naval Architects of Japan, Jun. 1995, Journal of the Society of Naval Architects of Japan, (177), 207 - 217, English

    [Refereed]

    Scientific journal

  • Analyses on Low Cycle Resonance of Ship in Astern Seas

    HAMAMOTO Masami, UMEDA Naoya, MATSUDA Akihiko, SERA Wataru

    the Society of Naval Architects of Japan, Jun. 1995, Journal of the Society of Naval Architects of Japan, (177), 197 - 206, English

    [Refereed]

    Scientific journal

  • 制約水域における避航操船の困難度評価 -操船環境総合化モデルの実用化へのアプローチ-

    井上 欣三, 宇佐美 茂, SERA Wataru

    日本航海学会, Sep. 1994, 日本航海学会論文集, (91), 213 - 220, Japanese

    [Refereed]

    Scientific journal

  • 避航操船の困難度評価指標の開発 -操船環境総合化モデルの提案-

    井上 欣三, 宇佐美 茂, SERA Wataru

    日本航海学会, Sep. 1993, 日本航海学会論文集, (89), 187 - 195, Japanese

    [Refereed]

    Others

  • 嶋田 博行, 井上 欣三, SERA Wataru

    Ship maneuvering includes human monitoring performance which demands sustained attention, i.e., vigilance. On an ocean voyage navigators are required to respond targets with rare appearance. The present study investigated the effects of extremely low frequency of appearance of targets on visual vigilance tasks. 45 subjects were required to respond visual target signal on the CRT with one hand. A 5 (interstimulus interval : ISI) ×3 (secondary tasks) analysis of variance with repeated measures was performed on the response times. Two main effects were significant, but interactive effect nonsignificant. Secondary tasks consist of visual task or auditory task. While subjects wait for appearance of target, they were required to read letters (visual secondary task) or to shadow auditory letter (auditory secondary task). Reaction times were slower and error rates were higher when ISI of targets was longer. It suggested that long waiting-time makes vigilance decrement. In visual secondary task condition vigilance decrement was remarkable, conversely in auditory task condition it was the same level as in the control condition without secondary tasks. Auditory tasks during ship maneuvering might make no effects on sustained attention.

    日本航海学会, Sep. 1992, 日本航海学会論文集, 87 (87), 67 - 72, Japanese

    [Refereed]

    Scientific journal

Presentations

  • 狭水道におけるESI マップ作成手法と有効性の検証

    Masanori Watagawa, Masao Furusho, Wataru Sera, Hiroyuki Shimada

    日本航海学会第123回講演会, Oct. 2010, Japanese, 社団法人日本航海学会, 鳥羽市民文化会館, Domestic conference

    Oral presentation

  • 動画を用いた技能継承手法のロープワーク教育への適用

    SERA Wataru, NAGAMATSU TAKASHI, KAMAHARA JUNZO, 海江田 洋平

    日本航海学会 第120回講演会, 2009, Japanese, Domestic conference

    Oral presentation

  • Development of a Simple Technique to Predict Ship Response in a Seaway

    Wataru SERA

    Pacific 2006 International Maritime Conference, Feb. 2006, English, Sydney Convention and Exhibition Centre, Australia, International conference

    Oral presentation

Research Projects