Research activity information

• May 2025 Japan Society of Naval Architecture and Ocean Engineering, Award of JASNAOE, ractical Method for Evaluating Wind Influence on Autonomous Ship Operations (2nd Report)

  Maki, A., Maruyama, Y., Dostal, L., Sasa, K., Sawada, R., Wakita, K.


• Apr. 2025 Elsevier, Top Reviewer 2024, Applied Ocean Research

  Kenji Sasa


• May 2011 JAPAN INSTITUTE OF NAVIGATION, 日本航海学会賞, 港外避泊時の船体運動を再現する諸要素に関する基礎的研究、日本航海学会論文集、第123号、pp.143-151、2010

  Kenji SASA, Atilla Incecik

  2010年度の日本航海学会論文賞に選定された

  International academic award

  共同研究・競争的資金等の業績IDIRI

• Quantitative analysis of a ship anchor dragging accident in extreme weather: A rapid intensification tropical cyclone case

  Haoyu Chen, Chen Chen, Kenji Sasa, Yongtao Xi, Jing Xu

  Elsevier BV, Jul. 2025, Ocean Engineering, 333, 121392 - 121392, English

  [Refereed]

  Scientific journal


• Statistical Validation of a Global Meteorological Database to Evaluate the Condensation Probability of Containers

  Ping Chi Yuen, Kenji Sasa, Hideo Kawahara, Sang-Won Lee

  Corresponding, Mar. 2025, Transaction of Navigation, 10(1) (1), 12 - 23, English

  [Refereed]

  Scientific journal


• Study on the forecasting of two cold surge events from the viewpoint of maritime transport

  Chen Chen, Haoyu Chen, Kenji Sasa

  Mar. 2025, Meteorological Applications, 32(2) (2), 1 - 17, English

  [Refereed]

  Scientific journal


• Carbon Intensity Indicator (CII) Compliance: Applications of Ship Speed Optimization on Each Level Using Measurement Data

  Duowen Yan, Chen Chen, Weidong Gan, Kenji Sasa, Guanghua He, Hongchu Yu

  Elsevier BV, Mar. 2025, Marine Pollution Bulletin, 212, 117593 - 117593, English

  [Refereed]

  Scientific journal


• A Study on Ship Mooring Status of Training Ships in Ports and Harbors for Emergency Operations of Earthquake and Tsunami Disasters

  Shigeki SAKAKIBARA, Yasuhiro KIMURA, Kenji SASA, Yoshiji YANO, Masayoshi KUBO

  Japan Institute of Navigation, Jan. 2025, The Journal of Japan Institute of Navigation, 151, 33 - 45, Japanese

  [Refereed]

  Scientific journal


• Effects of Swell Waves Caused by Atmospheric Depression on Ships Sailing in the North Pacific Ocean

  Sang-Won Lee, Kenji Sasa, Tomoya Masagaki, Chen Chen

  Corresponding, Elsevier BV, Nov. 2024, Ocean Engineering, 312, 119121 - 119121, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Optimal maintenance support system for offshore structures based on wave prediction and motion analysis with NOWPHAS

  Kaichi Takeuchi, Kenji Sasa, Sang-Won Lee

  Corresponding, Elsevier BV, Oct. 2024, Ocean Engineering, 309, 118350 - 118350, English

  [Refereed]

  Scientific journal


• Practical method for evaluating wind influence on autonomous ship operations (2nd report)

  Atsuo Maki, Yuuki Maruyama, Leo Dostal, Kenji Sasa, Ryohei Sawada, Kouki Wakita

  Abstract Recently, a considerable number of research and development projects have focused on automatic vessels. A highly realistic simulator is needed to validate control algorithms for autonomous vessels. For instance, when considering the automatic berthing/unberthing of a vessel, the effect of wind in such low-speed operations cannot be ignored because of the low rudder performance during slow harbor maneuvers. Therefore, a simulator used to validate an automatic berthing/unberthing control algorithm should be able to reproduce the time histories of wind speed and wind direction realistically. Therefore, in our first report on this topic, to obtain the wind speed distribution, we proposed a simple algorithm to generate the time series and distribution of wind speed only from the mean wind speed. However, for wind direction, the spectral distribution could not be determined based on our literature surveys, and hence, a simple method for estimating the coefficients of the stochastic differential equation (SDE) could not be proposed. In this study, we propose a new methodology for generating the time history of wind direction based on the results of Kuwajima et al.’s work. They proposed a regression equation of the standard deviation of wind direction variation for the mean wind speed. In this study, we assumed that the wind direction distribution can be represented by a linear filter as in our previous paper, and its coefficients are derived from Kuwajima’s proposed equation. Then, as in the previous report, the time series of wind speed and wind direction can be calculated easily by analytically solving the one-dimensional SDE. The joint probability density functions of wind speed and wind direction obtained by computing them independently agree well with the measurement results.

  Springer Science and Business Media LLC, Aug. 2024, Journal of Marine Science and Technology, 29, 876 - 884, English

  [Refereed]

  Scientific journal


• A Consideration on Safe and Efficient Operation of Offshore Structures Using Ocean Wave Information Facing Open Seas

  Kaichi TAKEUCHI, Kenji SASA

  Corresponding, Japan Institute of Navigation, Jul. 2023, The Journal of Japan Institute of Navigation, 148(148) (148), 18 - 26, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Safety evaluation of lashed trailer motions in ferry operations under rough sea conditions

  Kenji Sasa, Sang-Won Lee, Ryotaro Shimada, Toru Takagaki, Daisuke Terada

  Lead, Elsevier BV, May 2023, Ocean Engineering, 275, 114114 - 114114, English

  [Refereed]

  Scientific journal


• Basic Survey on Emergency Operation for Vessels and Ports in Case of Earthquake and Tsunami

  Yasuhiro KIMURA, Kenji SASA, Daichi HARA, Masayoshi KUBO

  Japan Institute of Navigation, Jan. 2023, The Journal of Japan Institute of Navigation, 147, 1 - 8, Japanese

  [Refereed]

  Scientific journal


• Enhanced estimation method and approximation method of the PDF of roll angular acceleration and jerk in beam seas

  Atsuo Maki, Leo Dostal, Yuuki Maruyama, Kenji Sasa, Masahiro Sakai, Naoya Umeda

  Elsevier BV, Nov. 2022, Ocean Engineering, 264, 112159 - 112159, English

  [Refereed]

  Scientific journal


• Practical method for evaluating wind influence on autonomous ship operations

  Atsuo Maki, Yuuki Maruyama, Leo Dostal, Masahiro Sakai, Ryohei Sawada, Kenji Sasa, Naoya Umeda

  Springer Science and Business Media LLC, Sep. 2022, Journal of Marine Science and Technology, 27(4) (4), 1302 - 1313, English

  [Refereed]

  Scientific journal


• Comparative Study of Realistic Ship Motion Simulation for Optimal Ship Routing of a Bulk Carrier in Rough Seas

  Kurniawan T. Waskito, Kenji Sasa, Chen Chen, Yasushi Kitagawa, Sang-Won Lee

  Corresponding, Elsevier BV, Sep. 2022, Ocean Engineering, 260, 111731 - 111731, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Novel Safety Evaluation Technique for Ships in Offshore Anchorage Under Rough Seas Conditions for Optimal Ship Routing

  Sang-Won Lee, Kenji Sasa, Chen Chen, Kurniawan T. Waskito, Ik-Soon Cho

  Corresponding, Elsevier BV, Jun. 2022, Ocean Engineering, 253, 111323 - 111323, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Evaluation of ship performance for small-sized container ship with actual sea database in the Pacific Ocean along Japanese coast

  Maeda, M, Sasa, K, Terada, D, Oda, H, Tanaka, Y, Kosao, M, Asaki, K

  Corresponding, CRC Press, May 2022, Trends in Maritime Technology and Engineering, 1, 373 - 380, English

  [Refereed]

  In book


• Multiple analysis for optimal ship routing simulation of 28,000-DWT bulk carrier in the Southern Hemisphere

  Tanaka, J, Sasa, K, Maki, A, Chen, C

  Corresponding, CRC Press, May 2022, Trends in Maritime Technology and Engineering, 1, 461 - 468, English

  [Refereed]

  In book


• Theoretical estimation of joint probability density function of roll angle and angular acceleration in beam seas using PDF line integral method

  Atsuo Maki, Leo Dostal, Yuuki Maruyama, Kenji Sasa, Masahiro Sakai, Kei Sugimoto, Yusuke Fukumoto, Naoya Umeda

  Springer Science and Business Media LLC, Mar. 2022, Journal of Marine Science and Technology, 27(1) (1), 814 - 822, English

  [Refereed]

  Scientific journal


• Statistical Estimation of Container Condensation in Marine Transportation between Far East Asia and Europe

  Ping Chi Yuen, Kenji Sasa, Hideo Kawahara, Chen Chen

  Condensation inside marine containers occurs during voyages owing to weather changes. In this study, we define the condensation probability along one of the major routes for container ships between Asia and Europe. First, the inside and outside air conditions were measured on land in Japan, and a correlation analysis was conducted to derive their relationship. Second, onboard measurements were conducted for 20,000 twenty-foot equivalent unit (TEU) ships to determine the variation in outside air conditions. Complicated patterns of weather change were observed with changes in latitude, sea area, and season. Third, condensation probability was estimated based on a multi-regression analysis with land and onboard measured data. The maximum condensation probability in westbound or eastbound voyages in winter was found to be approximately 50%. The condensation probability estimation method established in this study can contribute to the quantification of cargo damage risks for the planning of marine container transportation voyages.

  Corresponding, Cambridge University Press (CUP), Jan. 2022, Journal of Navigation, 75(1) (1), 176 - 199, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Estimation of Characteristics of Waves Encountered with a Ship by Using a Set of Data Obtained from Draft Measurement System

  Daisuke TERADA, Makoto KOSAO, Hiroyuki ODA, Kenji SASA, Yoshikazu TANAKA

  Japan Institute of Navigation, Dec. 2021, The Journal of Japan Institute of Navigation, 145, 47 - 55, Japanese

  [Refereed]

  Scientific journal


• New Evaluation of Ship Mooring with Friction Effects on Mooring Rope and Cost-Benefit Estimation to Improve Port Safety

  Sang-Won Lee, Kenji Sasa, Shin-ich Aoki, Kazusei Yamamoto, Chen Chen

  Corresponding, Elsevier BV, Nov. 2021, International Journal of Naval Architecture and Ocean Engineering, 13, 306 - 320, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Statistical Analysis of Waves’ Effects on Ship Navigation Using High-Resolution Numerical Wave Simulation and Shipboard Measurements

  Chen Chen, Kenji Sasa, Jasna Prpić-Oršić, Takaaki Mizojiri

  Elsevier BV, Jun. 2021, Ocean Engineering, 229, 108757 - 108757, English

  [Refereed]

  Scientific journal


• 実船データとの比較による南半球海域を対象とした最適運航モデルについて

  田中穣一朗, 笹 健児, 陳 辰

  Corresponding, May 2021, 日本船舶海洋工学会講演会論文集, 32, 121 - 124, Japanese

  Scientific journal


• 荒天航海における大型フェリーの車両貨物挙動シミュレーション

  島田遼太郎, 笹 健児

  Corresponding, May 2021, 日本船舶海洋工学会講演会論文集, 32, 117 - 120, Japanese

  Scientific journal


• Speed Loss Analysis and Rough Wave Avoidance Algorithms for Optimal Ship Routing Simulation of 28,000-DWT Bulk Carrier

  Sasa, K., Chen, C., Fujimatsu, T., Shoji, R., Maki, A.

  Lead, Elsevier BV, May 2021, Ocean Engineering, 228, 108800 - 108800, English

  [Refereed]

  Scientific journal


• Analysis of Ship Maneuvering Difficulties under Severe Weather Based on Onboard Measurements and Realistic Simulation of Ocean Environment

  Qianfeng Jing, Kenji Sasa, Chen Chen, Yong Yin, Hironori Yasukawa, Daisuke Terada

  Corresponding, Elsevier BV, Feb. 2021, Ocean Engineering, 221, 108524 - 108524, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Effects of GPV Datasets on WRF Modelling of Ocean Surface Wind in Rough Seas

  Chen, C, Sasa, K, Ohsawa, T, Terada, D

  Nov. 2020, Developments in Maritime Technology and Engineering, 1, 11 - 18, English

  [Refereed]

  In book


• Multiple Evaluations of Speed Loss in Rough Sea Voyages for 28,000-DWT Bulk Carrier

  Sasa, K, Terada, D, Uchiyama, R, Chen, C, Prpić-Oršić , J

  Lead, CRC Press, Nov. 2020, Developments in Maritime Technology and Engineering, 1, 53 - 61, English

  [Refereed]

  In book


• Analysis of the Onboard Weather Conditions Governing Container Condensation in Voyage between Asia and Europe

  Yuen, K.Sasa, KKawahara, HChen C

  Nov. 2020, Conference proceedings, the Japan Society of Naval Architects and Ocean Engineers, 31, 315 - 320, English

  Symposium


• Comparative Assessment of NCEP and ECMWF Global Datasets and Numerical Approaches on Rough Sea Ship Navigation Based on Numerical Simulation and Shipboard Measurements

  Chen Chen, Kenji Sasa, Teruo Ohsawa, Masashi Kashiwagi, Jasna Prpić-Oršić, Takaaki Mizojiri

  Elsevier BV, Aug. 2020, Applied Ocean Research, 101, 102219 - 102219, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Uncertainties of Ship Speed Loss Evaluation Under Real Weather Conditions

  Jasna Prpić-Oršić, Kenji Sasa, Marko Valčić, Odd Magnus Faltinsen

  A correct assessment of the ship speed loss in conditions of operation is becoming increasingly important for ship owners as well as ship designers. We are witnessing increasing concern for the environment and awareness of the necessity to preserve it as much as we could. The ship speed drop in the real environmental conditions can cause increased fuel consumption as well as increased emissions of CO2 and other greenhouse gases (GHGs) from ships. Decrease in the ship speed in real conditions is a consequence of the added resistance due to the impact of weather conditions and due to aggravated propeller working conditions. Moreover, the solution estimation of this problem is very much affected by human factors. Ship master, concerning for safety, can make a judgment that under certain adverse weather loads, it is necessary to slowdown or change ship's course to moderate or bypass the worst condition. In addition, the loading condition of the ship is constantly changing, which governs the basic parameters of the ship: the mass and mass moment of inertia, draft and trim and, consequently, the ship behavior at sea. All these parameters affect the assessment of ship speed, and it is necessary to be conscious of the intensity of their impact on the final value. At the same time, they cannot be predicted with absolute certainty, so the purpose of this analysis is to estimate the impact of weather and operational uncertainties on the actual speed of the ship in real operating conditions.

  ASME International, Jun. 2020, Journal of Offshore Mechanics and Arctic Engineering, 142(3) (3), English

  [Refereed]

  Scientific journal


• Comparative Study on WRF Model Simulations from the Viewpoint of Optimum Ship Routing

  Chen, C, Sasa, K, Ohsawa, T, Prpić-Oršić, J

  Apr. 2020, Ocean Engineering, 207, 107309 - 107309, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Improving the Performance of Dynamic Ship Positioning Systems: A Review of Filtering and Estimation Techniques

  Denis Selimović, Jonatan Lerga, Jasna Prpić-Oršić, Sasa Kenji

  Various operations at sea, such as maintaining a constant ship position and direction, require a complex control system. Under such conditions, the ship needs an efficient positioning technique. Dynamic positioning (DP) systems provide such an application with a combination of the actuators mechanism, analyses of crucial ship variables, and environmental conditions. The natural forces of induced nonlinear waves acting on a ship’s hull interfere with the systems. To generate control signals for actuators accurately, sensor measurements should be filtered and processed. Furthermore, for safe and green routing, the forces and moments acting on the ship’s hull should be taken into account in terms of their prediction. Thus, the design of such systems takes into account the problem of obtaining data about the directional wave spectra (DWS). Sensor systems individually cannot provide high accuracy and reliability, so their measurements need to be combined and complemented. Techniques based on the recursive Kalman filter (KF) are used for this purpose. When some measurements are unavailable, the estimation procedure should predict them and, based on the comparison of theoretical and measured states, reduce the error variance of the analyzed signals. Different approaches for improving estimation algorithms have evolved over the years with the indication of improvement. This paper gives an overview of the state-of-the-art estimation and filtering techniques for providing optimum estimation states in DP systems.

  MDPI AG, Mar. 2020, Journal of Marine Science and Engineering, 8(4) (4), 234 - 234, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Numerical Investigation on the Scharnov Turn Maneuver for Large Vessels

  Jing, Q., Sasa, K., Chen, C., Zhang, X., and Yin, Y.

  Corresponding, Mar. 2020, Transaction of Navigation, 5(1) (1), 17 - 27, English

  [Refereed]

  Scientific journal


• Real–Time Statistical Prediction of Pitching by Using Measurement Data

  TERADA Daisuke, KOSAO Makoto, TANAKA Yoshikazu, SASA Kenji

  Nov. 2019, Conference proceedings, the Japan Society of Naval Architects and Ocean Engineers, 29, 293 - 295, Japanese

  Scientific journal


• Evaluation of speed loss in bulk carriers with actual data from rough sea voyages

  Kenji Sasa, Kaichi Takeuchi, Chen Chen, Odd Magnus Faltinsen, Jasna Prpić-Oršić, Marko Valčić, Tomislav Mrakovčić, Naoki Herai

  Sep. 2019, Ocean Engineering, 187, 106162 - 106162

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• NEW EVALUATION FOR MOORING PROBLEM FROM COST-BENEFIT EFFECT

  笹 健児, 青木 伸一, 藤田 知宏, 陳 辰

  土木学会, 2019, 土木学会論文集. B2, 海岸工学 Journal of Japan Society of Civil Engineers. 土木学会海岸工学委員会 編, 75(2) (2), I_1243 - 1248, Japanese

  [Refereed]

  Scientific journal


• On Time-Frequency Characteristics of Fluctuation for Main Engine Rotational Speed in Rough Seas

  Daisuke TERADA, Kenji SASA, Nobukazu WAKABAYASHI

  Japan Institute of Navigation, 2019, The Journal of Japan Institute of Navigation, 141, 1 - 8, Japanese

  [Refereed]

  Scientific journal


• Estimation and comparison of accuracy in various data resolutions on optimal ship routing across the North Pacific Ocean

  Kenji Sasa, Takuya Fujimatsu, Chen Chen, Ruri Shoji

  American Society of Mechanical Engineering, 2019, Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, 3, 1 - 10, English

  [Refereed]

  International conference proceedings


• CURRENT ANALYSIS OF SHIP MOORING AND EMERGENCY SAFE SYSTEM

  SASA KENJI, MITSUI MASAO, AOKI SHINICHI, TAMURA MASAHIKO

  土木学会, Nov. 2018, 土木学会論文集B2（海岸工学）, 74(2) (2), I_1399 - I_1404, Japanese

  [Refereed]

  Scientific journal


• A Comparison of Simulated Results of Weather Routing for the Difference of Data Resolution

  FUJIMATSU TAKUYA, SASA KENJI, CHEN CHEN, SHOJI RURI

  日本船舶海洋工学会, Nov. 2018, 日本船舶海洋工学会講演会論文集, 27(27) (27), 517 - 521, Japanese

  Scientific journal


• Survey and Analysis on Safety of Ship Mooring Operations in Japanese Ports Facing Open Seas

  SASA KENJI, MITSUI MASAO, TAMURA MASAHIKO

  ASME, Jun. 2018, Proceedings of the 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2018, 1 - 8, English

  [Refereed]

  International conference proceedings


• Energy Efficiency of Ship Under Real Weather Conditions

  PRPIC-ORSIC, JASNA, SASA KENJI, VALCIC, MARKO, FALTINSEN, ODD

  ASME, Jun. 2018, Proceedings of the 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2018, 1 - 7, English

  [Refereed]

  International conference proceedings


• 実海域データより見た荒天航海時の船速低下を支配する諸要因に関する基礎研究

  TAKEUCHI KAICHI, SASA KENJI, PRPIC-ORSIC, J, FALTINSEN, O.M, MIWA TAKASHI, HASHIMOTO HIROTADA

  日本船舶海洋工学会, May 2018, 日本船舶海洋工学会講演会論文集, (26) (26), 369 - 374, Japanese

  Scientific journal


• Rough wave simulation and validation using onboard ship motion data in the Southern Hemisphere to enhance ship weather routing

  Li-Feng Lu, Kenji Sasa, Wataru Sasaki, Daisuke Terada, Toshiyuki Kano, Takaaki Mizojiri

  Corresponding, Nov. 2017, OCEAN ENGINEERING, 144, 61 - 77, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• 外洋航行中の大型フェリーにおける車両貨物の安全性を支配する諸要因について-オンボード計測データを用いた一考察-

  TAKAGAKI TORU, SASA KENJI, TERADA DAISUKE

  日本船舶海洋工学会, Nov. 2017, 日本船舶海洋工学会講演会論文集, (25) (25), 559 - 564, Japanese

  Scientific journal


• ウェザールーティングにおける荒天航海時の風波再現性に関する比較検証

  TAISHI YONEMURA, SASA KENJI, LU LI-FENG, TERUO OSAWA

  日本船舶海洋工学会, Nov. 2017, 日本船舶海洋工学会講演会論文集, (25) (25), 589 - 594, Japanese

  Scientific journal


• OPTIMAL ROUTING WITH TWO-STEP PREDICTION OF MOORING CRITERIA

  SASA KENJI, TAKEUCHI KAICHI, TAMURA MASAHIKO, MITSUI MASAO

   It is inevitalble to maintain safe area inside harbor for ships. However, many ports still have operational difficulty related on moored ship motions. This study aims to contribute for the optimal ship routing from viewpoint of mooring criteria. The correlation coefficients are 0.75-0.9 between 1-hour ahead predicted and measured wave heights. Suspensions of ferry service are accurately simulated here. The two-step prediction of mooring criteria consists of these parts, and enables to estimate ship motions of moored ferry in the ports in Okinawa 1 hour ahead. The strike ratio of prediction is 85-93% for 33 days that the ferry service were canceled in 2016. It is expected to contribute as the optimal routing of short-distance ferry, and does not require big investiments of building breakwaters or new mooring facilities.

  Japan Society of Civil Engineering, Oct. 2017, Journal of Japan Society of Civil Engineers, Series B2 (Coastal Engineering), 73(2) (2), I_1459 - I_1464, Japanese

  [Refereed]

  Scientific journal


• Development and validation of speed loss for a blunt-shaped ship in two rough sea voyages in the Southern Hemisphere

  Kenji Sasa, Odd Magnus Faltinsen, Li-Feng Lu, Wataru Sasaki, Jasna Prpic-Orsic, Masashi Kashiwagi, Takuro Ikebuchi

  Sep. 2017, OCEAN ENGINEERING, 142, 577 - 596, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• comparison of ship's speed loss in waves in some numerical simulation methods

  Sasa Kenji, Faltinsen Odd M., Kashiwagi Masashi

  神戸大学大学院海事科学研究科附属国際海事研究センター, Aug. 2017, Journal of maritime researches, 7, 87 - 99, English

  Link to Kobe Univ. Repository (Kernel)


• Basic Study on the Development of Weather Routing Part I -Estimation of Encounter Waves at Rough Sea Voyages in the Southern Hemisphere-

  SASA KENJI, LU LI-FENG, SASAKI WATARU, TERADA DAISUKE, KANO TOSHIYUKI, MIZOJIRI TAKAAKI

  The importance of transportation has been recognized when a city function is destroyed by natural disasters, such as the Great East Japan Earthquake or Kumamoto Earthquakes, etc. Sea transportation accounts for more than 95 percents of logistic cargos. It is also required to operate ships more efficiently and environment-friendly. This might relates to the fact that few weather database there than in the subtropical zone or the Northern Hemisphere. This study shows three measured results of rough sea navigations of 28,000DWT class bulk carrier in the Southern Hemisphere. Waves and winds are numerically computed by different models, and the computed results are validated with measured data. Moreover, the validation on ship motions is carried out using response functions. The possibility of wave estimation in the Southern Hemisphere is shown from measured and simulated results.

  Japan Society of Naval Architechiture and Ocean Engineers, Jun. 2017, Journal of Japan Society of Naval Architechiture and Ocean Engineers, 25(25) (25), 157 - 173, Japanese

  [Refereed]

  Scientific journal


• OPTIMAL ROUTING OF SHORT-DISTANCE FERRY FROM THE EVALUATION OF MOORING CRITERIA

  Kenji Sasa

  2017, PROCEEDINGS OF THE ASME 36TH INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING, 2017, VOL 6, 1 - 8, English

  [Refereed]

  International conference proceedings


• Comparison of Ship’s Speed in Waves in Some Numerical Simulation Methods

  SASA KENJI, FLATNESS ODD M, KASHIWAGI MASASHI

  Organizer of VF2016, Mar. 2016, Proceedings of 3rd International Conference on Violent Flows 2016, 3, 1 - 7, English

  International conference proceedings


• STARTING SYSTEM FOR DARRIEUS WATER TURBINE OF TIDAL STREAM ELECTRICITY GENERATION

  Seiji Shimizu, Masayuki Fujii, Tetsuya Sumida, Kenji Sasa, Yasuhiro Kimura, Eishi Koga, Hisaya Motogi

  2016, PROCEEDINGS OF THE ASME 35TH INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING , 2016, VOL 6, 6, English

  [Refereed]

  International conference proceedings


• A BASIC STUDY ON SHIP SPEED LOSS FROM THE VIEWPOINT OF GEOGRAPHIC CONDITIONS AND SHIP PERFORMANCE

  Kenji Sasa, Li-Feng Lu, Chen Chen

  2016, PROCEEDINGS OF THE ASME 35TH INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING , 2016, VOL 6, 6, English

  [Refereed]

  International conference proceedings


• Study on a Numerical Navigation System in the East China Sea

  CHEN CHEN, SHIOTANI SHIGEAKI, SASA KENJI

  Elsevier, Dec. 2015, Applied Ocean Research, 53, 257 - 266, English

  [Refereed]

  Scientific journal


• Evaluation of Simulated Navigation System and Sea Navigation System

  RYU XINZHU, SHIOTANI SHIGEAKI, SASA KENJI

  Japan Society of Civil Engineering, Nov. 2015, Annual Journal of Civil Engineering in the Ocean, JSCE, 71(2) (2), 197 - 202, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Evaluation of Ship Performance in International Maritime Transportation using an Onboard Observation System—In Case of a Bulk Carrier for International Voyages—

  SASA KENJI, TERADA DAISUKE, SHIOTANI SHIGEAKI, WAKABAYASHI NOBUKAZU, IKEBUCHI TAKURO, CHEN CHEN, TAKAYAMA ATSUYOSHI, UCHIDA MAKOTO

  Elsevier, Jun. 2015, Ocean Engineering, 104, 294 - 309, English

  [Refereed]

  Scientific journal


• Effect of Ocean Currents on Ship Navigation in the East China Sea

  CHEN CHEN, SHIOTANI SHIGEAKI, SASA KENJI

  Elsevier, Jun. 2015, Ocean Engineering, 104, 283 - 293, English

  [Refereed]

  Scientific journal


• Evaluation of Speed Loss in Seaways Combining Seakeeping and Propulsion Theory

  SASA KENJI, FALTINSEN, ODD M

  Japan Society of Naval Architects and Ocean Engineers, May 2015, Conference Proceedings of Japan Society of Naval Architects and Ocean Engineers, (20) (20), 65 - 68, English

  International conference proceedings


• BASIC STUDY ON WAVES FAR FROM COASTAL AREA AND APPLICATION FOR SHIP OPERATION

  SASA Kenji, CHEN Chen, SHIOTANI Shigeaki, WAKABAYASHI Nobukazu, TERADA Daisuke

   There is little information of waves far from coastal zones currently, the possibility of wave information is studied here by using a wave radar analyzer and numerical simulation models, WRF and SWAN. It is assured that measured wave data is practically enough accurate to apply for ship operation. On the other hand, computed results in numerical models underestimate wave heights a little. It is necessary to accumulate wave data in many ships from now on, and it will help to correct wave height accurately. The wave information service far from coastal areas is expected to construct.

  Japan Society of Civil Engineers, 2015, Journal of Japan Society of Civil Engineers, Ser. B3 (Ocean Engineering), 71(2) (2), I_185 - I_190, Japanese

  [Refereed]

  International conference proceedings

  Link to Kobe Univ. Repository (Kernel)


• Effects of Weather and Ocean on Ship Traffic in the Eastern Seto Inland Sea

  CHEN CHEN, SHIOTANI SHIGEAKI, SASA KENJI

  Waves, currents, and winds are important factors for safe and economic ship navigation, especially in coastal areas where ship density is relatively higher and the topography is more complicated. In this research, the eastern Seto Inland Sea, also known as the Harima Nada area, was selected for conducting numerical ship navigation. Ship traffic information was given from AIS, and WRF, SWAN, and POM models were used to produce numerical simulations of wind, waves, and currents, respectively.
   The high-resolution weather and ocean information was then used to conduct numerical ship navigation. To verify their accuracy, results simulating the weather and ocean were compared with actual observation data. The findings showed that the estimation of a ship's position using the proposed numerical navigation simulation method was effective in helping a ship navigate safely and economically.

  JAPAN SOCIETY OF CIVIL ENGINEERING, Nov. 2014, Annual Journal of Civil Engineering in the Ocean, JSCE, 70(2) (2), 942 - 947, English

  [Refereed]

  Scientific journal


• Simulation of Vessel Evacuation after the Great Japan Earthquake in a Virtual Globe Environment

  RYU XINZHU, SHIOTANI SHIGEAKI, SASA KENJI

  Sep. 2014, Proceedings of International Sympojium INFORMATION ON SHIPS, 1 - 11, English

  [Refereed]

  International conference proceedings


• Effects of Weather on Container Ship Safety in a Coastal Area of Japan

  CHEN CHEN, SHIOTANI SHIGEAKI, SASA KENJI

  Sep. 2014, Proceedings of International Symposium INFORMATION ON SHIPS, 1 - 15, English

  [Refereed]

  International conference proceedings


• Study on Simulation of Ship Maneuvering in Arrival and Departure Using GIS

  RYU XINZHU, SHIOTANI SHIGEAKI, SASA KENJI

  Jun. 2014, Proceedings of the European Navigation Conference 2014, 1 - 12, English

  [Refereed]

  International conference proceedings


• Improvement of Rankine Panel Method by Theoretical Consideration of Panel Forces on Ship Hull

  SASA KENJI, KASHIWAGI MASASHI

  Mar. 2014, Proceedings of the 29th International Workshop on Water Waves and Floating Bodies, (29) (29), 177 - 180, English

  [Refereed]

  International conference proceedings


• ANNALYSIS OF SEA SHOCK ENCOUNTERED BY A SHIP IN NORTH EAST JAPAN

  Shigeaki Shiotani, Kenji Sasa

  2014, 33RD INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING, 2014, VOL 8A, English

  [Refereed]

  International conference proceedings


• EFFECTS OF WEATHER AND OCEAN ON SHIP TRAFFIC IN THE EASTERN SETO INLAND SEA

  CHEN CHEN, SHIOTANI SHIGEAKI, SASA KENJI

  Waves, currents, and winds are important factors for safe and economic ship navigation, especially in coastal areas where ship density is relatively higher and the topography is more complicated. In this research, the eastern Seto Inland Sea, also known as the Harima Nada area, was selected for conducting numerical ship navigation. Ship traffic information was given from AIS, and WRF, SWAN, and POM models were used to produce numerical simulations of wind, waves, and currents, respectively.
   The high-resolution weather and ocean information was then used to conduct numerical ship navigation. To verify their accuracy, results simulating the weather and ocean were compared with actual observation data. The findings showed that the estimation of a ship's position using the proposed numerical navigation simulation method was effective in helping a ship navigate safely and economically.

  Japan Society of Civil Engineers, 2014, 土木学会論文集 B3(海洋開発)(Web), 70(2) (2), I.942 - I.947 (J-STAGE), English

  [Refereed]

  Symposium


• NUMERICAL ANALYSIS OF FAILED FORECASTS OF WAVES UNDER LOW PRESSURES FROM VIEWPOINT OF SHIP OPERATION

  Kenji Sasa, Chen Chen, Shigeaki Shiotani, Teruo Ohsawa, Daisuke Terada

  2014, 33RD INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING, 2014, VOL 7, 7, English

  [Refereed]

  International conference proceedings


• Ship Motions of Cargo Ship in Stormy Condition at Actual Sea -Analysis and Estimation of Ship Motions and Wave Properties due to Onboard Data-

  SASA KENJI, TERADA DAISUKE, SHIOTANI SHIGEAKI, WAKABAYASHI NOBUKAZU, IKEBUCHI TAKURO

  Japan Society of Naval Architects and Ocean Engineers, Dec. 2013, Journal of the Japan Society of Naval Architects and Ocean Engineers, 18(18) (18), 167 - 175, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Sea Shock Measured by a Sailing Ship in North East Japan

  SHIOTANI SHIGEAKI, SASA KENJI

  日本沿岸域学会, Dec. 2013, Journal of Coastal Zone Studies, 26(3) (3), 117 - 127, Japanese

  [Refereed]

  Scientific journal


• Safety evaluation of the ferry carriage under large wave

  Keisuke Okada, KOBAYASHI EI-ICHI, Yuuki Taniguchi, SASA KENJI

  The Japan Sciety of Naval Archtects and Ocean Engineers, Nov. 2013, Coference proceedings, (17) (17), 195 - 198, Japanese

  Research society


• データ分析から見た船舶運航における波浪予報の現状と課題について

  SASA Kenji, SHIOTANI Shigeaki, TERADA Daisuke, WAKABAYASHI Nobukazu, OSAWA Teruo

  Numerical forecasts of weather and oceanography are in common in the field of ship operation, as the improvement of computer science these days. However, their accuracies is still unreliable in some situations. Here, nationwide questionnaire is implemented to make sure the current effectiveness of wave forecast from viewpoint of navigation safety. A couple of weather patterns are revealed as the difficulty of forecast. Moreover, two cases of failed forecast are analyzed with observed and forecasted database. These patterns are caused under the low pressure develops and moves north-easterly. Authors concludes that the backdrop has to be revealed why these weather patterns tend to misforcast in the future.

  Japan Society of Civil Engineers, Nov. 2013, 土木学会論文集B3（海洋開発）, 69(2) (2), I_61 - I_66, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Study on Navigational Simulation in Import and Outport Using GIS

  RYU XINZHU, NAKAO KENTA, HORIKAWA DAISUKE, SHIOTANI SHIGEAKI, SASA KENJI

  Most of the maritime disasters are caused by the immature technology, and insufficient knowledge of navigation. Especially, a ship encounters to many dangerous situation in importing and outporting. For the reduction of marine disaster, many appropriate navigational information are demended for a navigating officer.
   The present paper proposes the effective presentation for information of navigation using GIS and the efficiency of navigation simulation supporting safety navigation is examined for prevention of a marine disaster. In this study, authors discussed two method of supplying navigational information. The first method is by supplying the 3D model into GIS. The second one is embedding 360° panorama picture into GIS and a navigating officer can check the 360° view around before departure. It was comfimed that these proposed methods were very effective.

  JAPAN SOCIETY OF CIVIL ENGINEERING, Nov. 2013, Annual Journal of Civil Engineering in the Ocean, JSCE, 69(2) (2), I_610 - I_615, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Numerical ship navigation based on weather and ocean simulation

  Chen Chen, Shigeaki Shiotani, Kenji Sasa

  Sep. 2013, OCEAN ENGINEERING, 69(69) (69), 44 - 53, English

  [Refereed]

  Scientific journal


• 気象・海象を考慮した数値ナビゲーションシステムの基礎的研究

  SODA Taisuke, SHIOTANI Shigeaki, SASA Kenji

  It is considered that the weather and ocean such as the wind, the tidal current and the wave are the most important factors to a sailing ship. In this paper, the numerical calculation methods of the tidal current, the wind and the wave are proposed in the coastal sea area. In second, the numerical navigation system is investigated by the simulation. The purpose of this paper is to propose the numerical estimation methods of weather and ocean, and to discuss about the simulation of numerical navigation for a sailing ship under effects of numerical weather and ocean. The simulation of numerical navigation to a sailing ship is carried out under the effects of numerical weather and ocean. The proposed numerical navigation is very effective for the estimation of the ship position for a sailing ship. It was found that the numerical navigation system is possible to introduce to the weather routing system in the coastal sea region in future.

  The Japan Society of Naval Architects and Ocean Engineers, Feb. 2013, 日本船舶海洋工学会論文集, 16(16) (16), 155 - 164, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Application of Numerical Ship Navigation in a Coastal Area

  Chen Chen, Shigeaki Shiotani, Kenji Sasa

  2013, 2013 OCEANS - SAN DIEGO, English

  [Refereed]

  International conference proceedings


• Study of Tidal Stream Electricity Generation for Obatake Strait

  SHIMIZU Seiji, FUJII Masayuki, KOGA Eishi, SASA Kenji, KIMURA Yasuhiro, KITAKAZE Hiroshi

  2013, Proceedings of the 23rd International Conference of Offshore and Polar Engineering, English

  [Refereed]

  International conference proceedings


• Measurement of Sea-Shocks Response of a Sailing Ship in Japan

  SHIOTANI Shigeaki, SASA Kenji, WAKABAYASHI Nobukazu, TERADA Daisuke

  2013, Proceedings of the 23rd International Conference of Offshore and Polar Engineering, English

  [Refereed]

  International conference proceedings


• CURRENT SITUATION AND DIFFICULTY OF WAVE FORECAST FROM VIEWPOINT OF SHIP MANAGEMENT

  Kenji Sasa, Daisuke Terada, Shigeaki Shiotani, Nobukazu Wakabayashi, Teruo Ohsawa

  2013, PROCEEDINGS OF THE ASME 32ND INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING - 2013 - VOL 5, 5, English

  [Refereed]

  International conference proceedings


• On Time Series Analysis Concerning the Ship Acceleration Caused by Seaquake

  TERADA Daisuke, WAKABAYASHI Nobukazu, SASA Kenji, MATSUDA Akihiko

  Nov. 2012, Proceedings of Asia Navigational Conference 2012, 177 - 185, English

  [Refereed]

  International conference proceedings


• 荒天航海時の船体運動と海上輸送の安全・効率性の関係について

  SASA Kenji, TERADA Daisuke, SHIOTANI Shigeaki, WAKABAYASHI Nobukazu

  The balancing between safety and efficiency becomes imminent more than ever. It is caused by the global economic downturn, the steep rise of fuel oil price, etc. Shipping companies already installed the weather routing service for their controlled ships. However, it is necessary to consider the influence of ship motions more theoretically. Here, onboard measurements have been implemented for an ocean going bulk carrier to know relations between ship motions and other related parameters. Relational analysis is implemented against observed data to construct the total evaluation system of maritime transportation as "three principles of transportation."

  Japan Institute of Navigation, Sep. 2012, 日本航海学会論文集, 127(127) (127), 79 - 87, Japanese

  [Refereed]

  Scientific journal


• Fundamental Study on Tidal Currents in Obatake Seto from Viewpoint of Tidal Energy Generation

  SASA Kenji, SHIMIZU Seiji, FUJII Masayuki, KOGA Eishi

  Jun. 2012, Proceedings of the 22nd International Conference of Offshore and Polar Engineering, 680 - 687, English

  [Refereed]

  International conference proceedings


• Basic Study on Operational Evaluation of International Voyage from Viewpoint of Ship Motions and Oceanographic Database

  SASA Kenji, TERADA Daisuke, SHIOTANI Shigeaki, WAKABAYASHI Nobukazu, KOBAYASHI Eiichi, MAKINO Hidenari, SHIMADA Youichi, UCHIDA Makoto, TANEMOTO Jun

  May 2012, Proceedings of the Conference of the Japan Society of Naval Architects and Ocean Engineers, No.14, pp.107-110, Japanese

  International conference proceedings


• Numerical simulation of anchored ship motions due to wave and wind forces for enhanced safety in offshore harbor refuge

  Kenji Sasa, Atilla Incecik

  Apr. 2012, OCEAN ENGINEERING, 44, 68 - 78, English

  [Refereed]

  Scientific journal


• 航行安全および潮流発電から見た大畠瀬戸の潮流特性に関する基礎的研究

  SASA Kenji, SHIMIZU Seiji, KOGA Eishi, FUJII Masayuki

  The Obatake Seto, which locates in the Yamaguchi Pref. in western Japan, is famous for its strong tidal current. It sometimes makes ship navigation difficult. Casualties sometimes happen there because of strong tidal currents and complicated topography. Renewable and environmental friendly energy resources are inevitable to decrease the dependence with fossil fuels or nuclear energy. Authors pay attention the possibility on tidal current electric generation in the Obatake Seto. However, there is very few knowledge on spatial distribution of tidal currents around the Obtake Seto within 100 meters. In this study, properties of tidal currents are clarified through the field observation and numerical simulation from viewpoint of navigation safety and electric power generation.

  Japan Institute of Navigation, Mar. 2012, 日本航海学会論文集, 126(126) (126), 105 - 114, Japanese

  [Refereed]

  Scientific journal


• A Study of Numerical Simulations of Ship Motions While Underway Using a Coastal Wave Database

  Kenji Sasa, Daisuke Terada, Shigeaki Shiotani, Eiichi Kobayashi

  Mar. 2012, INTERNATIONAL JOURNAL OF OFFSHORE AND POLAR ENGINEERING, 22(1) (1), 38 - 45, English

  [Refereed]

  Scientific journal


• Data Analysis of Safety Evaluation of Outbound Cargo Carrier from Viewpoint of Ship Motions

  SASA Kenji, TERADA Daisuke, SHIOTANI Shigeaki, KOBAYASHI Eiichi, WAKABAYASHI Nobukazu, MAKINO Hidenari, SHIMADA Yoichi, UCHIDA Makoto

  Japan Institute of Navigation, 2012, NAVIGATION, 180, 42 - 47, Japanese


• A STUDY ON PORT PLANNING WITH BERTHING SHIP MOTIONS DUE TO STRONG TIDAL CURRENTS

  Kenji Sasa, Tadashi Hibino, Kyunghoi Kim

  Dec. 2011, COASTAL ENGINEERING JOURNAL, 53(4) (4), 319 - 342, English

  [Refereed]

  Scientific journal


• 国際海上輸送の安全性・効率性から見た貨物船の運航性能に関する研究/A Study on Operational Performance of Cargo Carrier from Viewpoint of Safety

  SASA Kenji, TERADA Daisuke, SHIOTANI Shigeaki, KOBAYASHI Eiichi, WAKABAYASHI Nobukazu, MAKINO Hidenari, SHIMADA Youichi, UCHIDA Makoto

  Nov. 2011, Proceedings of the Conference of the Japan Society of Naval Architects and Ocean Engineers, No.13, pp.303-306, Japanese

  International conference proceedings


• 動的係留力および波浪伝播を考慮した港外避泊船の安全性評価

  SASA Kenji, INCECIK Atilla

  土木学会, Nov. 2011, 土木学会論文集 B2(海岸工学), 67(2) (2), I_756 - I_760, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• 荒天時の船体運動と貨物損傷の関係について

  Kenji Sasa, Daisuke Terada, Nobukazu Wakabayashi

  The authors have studied on estimation of ship motions underway in heavy seas. Operators pay attention to avoid the cargo damage in this situation. It is necessary to know the relation between ship motions and cargo damage in this study. However, there is very little database related on cargo damage. In this study, the difficulty of cargo management is verified by interviews, wave and AIS database. Field observation is implemented on ship motions, accelerations on deck, and lashing wire tensions. Vertical accelerations of 1.5G occur on fore and aft deck, when pitch motion is around 2 degrees with the same peak frequencies. On the other hand, the peak frequency of lashing wire tensions is lower than that. These points have to be cleared in future studies.

  Japan Institute of Navigation, Sep. 2011, 日本航海学会論文集, 第125号,pp.199-207, 199 - 207, Japanese

  [Refereed]

  Scientific journal


• 沖合波浪およびAISデータを用いたフェリー海難の事故分析に関する研究

  SASA Kenji, WAKABAYASHI Nobukazu, KOBAYASHI Eiichi, TERADA Daisuke, SHIOTANI Shigeaki

  Jun. 2011, 土木学会論文集B3（海洋開発）, 67(4) (4), 1 - 6, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Numerical Navigation for a Ship in Simulation of Waves

  SHIOTANI Shigeaki, SASA Kenji, TERADA Daisuke, MAKINO Hidenari, SHIMADA Yoichi

  Jun. 2011, Proceedings of the 20th International Offshore Polar Engineering Conference, 663 - 668, English

  [Refereed]

  International conference proceedings


• 潮流が卓越する海域での港内静穏度について

  SASA Kenji, KIM Kyung Hoi

  The working ratio of ports has been discussed in detail, if the influence of waves is remarkable. On the other hand, it has not considered if they do not locate open sea areas. First, current port operation is clarified by the nationwide questionnaire. Tidal currents are the main factor that makes ferry operation difficult. The difficulty of ferry berthing is finally estimated by revised numerical simulations. The working ratio due to tidal current is newly defined to compare that due to waves. In the ferry terminal of the Seto Inland Sea, the working ratio due to tidal current is lower than the standard of harbour tranquility. Especially, new port planning is required for small sized ferry ports with strong tidal currents.

  Japan Institute of Navigation, Mar. 2011, 日本航海学会論文集, 124(124) (124), 319 - 328, Japanese

  [Refereed]

  Scientific journal


• NEW CONCEPT OF PORT PLANNING FOR SMALL FERRIES FROM THE VIEWPOINT OF BERTHING SHIP MOTIONS UNDER STRONG TIDAL CURRENTS

  Kenji Sasa, Kyunghoi Kim

  2011, OMAE2011: PROCEEDINGS OF THE ASME 30TH INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING, VOL 5, 5, 15 - +, English

  [Refereed]

  International conference proceedings


• 港外避泊時の船体運動を再現する諸要素に関する基礎的研究

  SASA Kenji, INCECIK Atilla

  It is inevitable to maintain safety when vessels cannot stay inside harbour due to stormy weathers. Authors summed up nationwide questionnaire about present offshore harbour refuge. It reveals the necessity of consideration about wave forces in anchored ship motions. Numerical simulation models are newly constructed to reproduce anchored ship motions under waves and winds. Especially, anchored ship motions have not been compared between catenary method and dynamic methods of anchor chain forces. Here, ship motions are simulated to compare differences against the casualty of 60,000DWT class grain carrier in Japan. Anchor chain forces become larger in the lumped mass method than those in the catenary method. They also become larger when we consider wave forces, so it means that proposed model of safety evaluation should be used.

  Japan Institute of Navigation, Sep. 2010, 日本航海学会論文集, 123(123) (123), 143 - 151, Japanese

  [Refereed]

  Scientific journal


• Safety Evaluation Method of Ship Berthing at Pontoon under Strong Current from Viewpoint of Ship Motions

  SASA Kenji, HIBINO Tadashi, KIM Kyung Hoi

  Jun. 2010, Proceedings of the 20th International Offshore and Polar Engineering Conference, 956 - 963, English

  [Refereed]

  International conference proceedings


• 強潮流下の港湾への着桟操船時の船体運動による安全性評価について

  SASA Kenji, HIBINO Tadashi, KIM Kyung Hoi

  The influence of ship operation due to tidal currents has not studied in detail. The first step of this study reveals that present port planning is quite insufficient for ships to berth in strong tidal currents. The field observation of sea water and tidal current around T Port makes obvious that grasp of water environment is inevitable, especially in places with complicated density flow. Furthermore, numerical simulations of berthing ship motions are fully improved to evaluate the safety of berthing in strong tidal currents and winds. Simulated results can almost reproduce observed ship motions. It also makes the definition of berthing criterion possible numerically. Finally, new evaluation method of port planning is proposed from viewpoint of berthing ship motions in strong tidal currents

  Japan Society of Civil Engineers, Nov. 2009, 海岸工学論文集, 56(2) (2), 1301 - 1305, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• 観測波を用いた沿岸航行の船体運動の再現性と欠航判断に関する研究

  SASA Kenji, TERADA Daisuke

  A safety of maritime transportation should be secured around harbours and open waters. However, the evaluation method about judge of ship cancellation has not been numerically modeled yet. It is inevitable to estimate ship motions during the coastal navigation. Here, the new concept of reproduction of ship motions is shown by using the coastal network wave database, NOWPHAS. A domestic ferry service, which navigates in the Pacific Ocean, is set as the object of this study. Firstly, field observations of ship motions were implemented when typhoons approached Japan in 2003-2004. Then, the reproduction accuracy is verified between two types of equations of motions. It shows that the impulse response method is inevitable to estimate large amplitudes pitch motions with detailed wave data as directional spectrums for the judge of cancellation.

  Japan Society of Civil Engineers, Nov. 2009, 海岸工学論文集, 56(2) (2), 856 - 860, Japanese

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• 縦運動の時系列シミュレーションの精度向上に関する研究

  SASA Kenji, TERADA Daisuke, SHIOTANI Shigeaki, KOBAYASHI Eiichi

  From viewpoint of ship safety and cargo management, in previous study we are cleared that it is very important for making a criterion of judgment of ferry cancel based on both observed ship motions when the ship encounters a typhoon and coastal wave data at that time. In this study, we attempted to improve the accuracy of numerical reproductions of ship motions based on observed coastal waves. The model considering the memory effect function is introduced. The verification of the model is carried out by using the data of ship motions were observed with 5,000GT type ferry boat, and the coastal wave data were recorded with NOWOHAS as well as our previous study. A couple of future problems with respect to the simulation model are considered.

  Japan Institute of Navigation, Sep. 2009, 日本航海学会論文集, 121(121) (121), 191 - 197, Japanese

  [Refereed]

  Scientific journal


• 船体運動と沿岸波浪に基づくフェリー欠航の判断基準に関する検討

  SASA Kenji, TERADA Daisuke, NAGAI Toshihiko, KAWAI Hiroyasu

  From viewpoint of a ship safety and a cargo management, the examination of a criterion of judge of ferry cancel is carried out, based on both observed ship motions when the ship encounters a typhoon and coastal wave data at that time. Ship motions are observed by using 5,000GT type ferry boat. And as the wave data, coastal waves that recorded with NOWOHAS instead of the encounter wave which can not be measured, are used. These data are analyzed by Spectral Analysis and the characteristics are analyzed in detail. Moreover, numerical reproductions of ship motions based on observed coastal waves are carried out, and a couple of future problems with respect to the decision of the criterion of judge of ferry cancel are considered.

  Japan Institute of Navigation, Mar. 2009, 日本航海学会論文集, 120(120) (120), 99 - 106, Japanese

  [Refereed]

  Scientific journal


• A STUDY ON JUDGMENT CRITERION FOR CANCELLATION OF FERRIES DUE TO SHIP MOTION AND COASTAL WAVE DATA

  TERADA Daisuke, SASA Kenji

  Japan Institute of Navigation, 2009, NAVIGATION, 171, 74 - 76, Japanese


• Report of the 28th of International Conference of Ocean, Offshore and Arctic Engineering (OMAE-2009)

  SASA Kenji

  Japan Institute of Navigation, 2009, NAVIGATION, 171, 70 - 71, Japanese


• NEW EVALUATION ON SHIP STRENGTH FROM THE VIEWPOINT OF STRANDED CASUALTIES IN COASTAL AREAS UNDER ROUGH WEATHER

  Kenji Sasa, Atilla Incecik

  2009, OMAE 2009, VOL 2, 2, 43 - 50, English

  [Refereed]

  International conference proceedings


• STUDY ON JUDGMENT CRITERION FOR CANCELLATION OF FERRIES DUE TO SHIP MOTION AND COASTAL WAVE DATA

  Daisuke Terada, Kenji Sasa

  2009, OMAE 2009, VOL 1, 1, 109 - 115, English

  [Refereed]

  International conference proceedings


• 瀬戸内海の離島での強潮流時の船舶運航から見た港湾計画のあり方

  SASA Kenji, HIBINO Tadashi, KIM Kyung Hoi, MIZUI Shinji

  The Seto Inland Sea is located among the main land, the Shikoku and the Kyushu. There are many isolated islands there, so it makes very complicated tidal conditions. Many of those isolated islands still depend on the maritime transportation. In this study, the difficulty of berthing due to strong currents is researched from viewpoint of port planning. At first, the influence on ferry operations due to oceanographic conditions is interviewed to the local ferry operators. Then, tidal currents and some other parameters have observed around the ferry port which the ferry berthing is difficult. The numerical simulation of ship motions is constructed to reproduce the situations under strong tidal currents. Simulated results can almost explain the difficulty of berthing caused by tidal currents. Finally, the new evaluation method of the port planning is proposed as the safety of ferry berthing in the Seto Inland Sea.

  Japan Society of Civil Engineers, Nov. 2008, 海岸工学論文集, 55(2) (2), 1356 - 1360, Japanese

  [Refereed]

  Scientific journal


• 荒天時における沿岸域での海難事故から見た船体強度に関する基礎的研究

  SASA Kenji, Atilla Incecik, NAGAI Toshihiko, MIZUI Shinji

  It is necessary to study on the safety of "the refugee of harbour" from the viewpoint of port planning, too. Recently, breakage casualties of stranded ships become very serious in the port operation and the coastal environment. However, these problems have not been discussed among the coastal engineering and shipbuilding, neither. In this study, we summarize the importance of this point by showing the statistic of casualties. Then, the strength of ship hulls is calculated with strip method and the basic dynamics of material, when ships are designed to navigate in the ocean. Since the calculated results cannot explain the breakage casualties, the possibility of the enlarged stress due to the crack is also considered as a simple example. The results can explain that the breakage of stranded ships may be caused by the enlarged stress due to cracks on the ship hull. Therefore, the safety of coastal areas outside harbour should be considered totally with anchored ship motions and fracture mechanics of ships in detail in the future.

  Japan Society of Civil Engineers, Jul. 2008, 海洋開発論文集, 24, 987 - 992, Japanese

  [Refereed]

  Scientific journal


• 荒天時の観測波を用いた港外避泊船の船体運動の再現性に関する研究

  SASA Kenji, Atilla Incecik, NAGAI Toshihiko, SHIMIZU Katsuyoshi, MIZUI Shinji

  In recent years, anchored vessels sometimes dragged their anchor and stranded incoastal zones during the evacuation at stormy weathers. It is very important to verify the accuracy of numerical simulation of anchored ship motions. In this study, some points of numerical simulations are improved to reproduce accurately the phenomenon of stranded casualties. The situation of the dragging anchor can be reproduced by solving the equation of motion at seabed. The approximated hydrodynamic forces of the anchor chain make the accuracy better. Finally, the detailedsituation can be reproduced by considering the dragging anchor, the drifting of ship and the hydrodynamic forces of mooring chain. It makes possible to simulateaccurately the safety of anchored vessels offshore harbour as the new planningscheme.

  Japan Society of Civil Engineers, Nov. 2007, 海岸工学論文集, 54(2) (2), 1321 - 1325, Japanese

  [Refereed]

  Scientific journal


• A study of the accuracy of on-air acoustic tide gauges in seas with 2398 large tidal amplitudes

  Kenji Sasa, Shinji Mizui, Toshihiko Nagai, Katsuyoshi Shimizu, Masao Mitsui

  2007, PROCEEDINGS OF THE SEVENTEENTH (2007) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 1- 4, PROCEEDINGS, 2398 - 2404, English

  [Refereed]

  International conference proceedings


• 潮位差の大きな実海域における空中発射型超音波潮位計の精度向上に関する研究

  SASA Kenji, NAGAI Toshihiko, KUWAGAKI Kazuo, HATTORI Shinichi

  The real-time observation system of water levels is required to establish along coastal areas. The on-air acoustic tide gauge is newly developed here. It does not require the installation of the well in the water, so the construction cost is expected to be lower than conventional types. However, the accuracy is not verified in detail at the sea area which has large amplitudes of tides. In this study, tide data is continuously observed at the observation point in the Seto Inland Sea after the installation. At first, the property of temperatures in the steel pipe of the tide guage is analyzed. The unevenness of temperatures is found, so we construct the algorithm of the correction of the acoustic velocity by using calibration bars. Finally, the improvement of the accuracy is confirmed by observed data.

  Japan Society of Civil Engineers, Jun. 2006, 海洋開発論文集, 22, 97 - 102, Japanese

  [Refereed]

  Scientific journal


• Basic Research on Stranding Accidents of Ships in Stormy Weathers From Viewpoint of Safety at Offshore Harbour Refuge

  SASA Kenji, NAGAI Toshihiko

  Jun. 2006, Proceedings of the 31st International Navigation Congress, 1 - 12, English

  [Refereed]

  International conference proceedings


• A Basic Study on Ship Nabigation Neer Cape

  Go KOBAYASHI, Masayoshi KUBO, Ik-soon CHO, Shiji MIZUI, Kenji SASA

  The Land, Infrastructure and Transportation Ministry of Japan has been promoted the "modal shift" as its major goal to establish the distribution system that does not rely on trucks too much. Maritime transportation is attracted attention as a suitable system for the modal shift. However, the maritime transportation has higher risk of cargo damage influenced by the weather and sea conditions than the land transportation. Some former studies showed that ship motion become large near the cape sea. Then, we researched on the problem at the time of a cape offing navigation at the Muroto cape. This study aims at understanding the issues that the ship navigation near cape. In this paper, the questionnaire carried out to the ferry companies which navigate near cape offing. Moreover, ship motions are measured by the field observation. And the observed results about the problem at the time of a cape offing navigation is analyzed in detail.

  Japan Institute of Navigation, Mar. 2006, The Journal of Japan Institute of Navigation, 第114号・pp.1-8, 1 - 7, Japanese

  [Refereed]

  Scientific journal


• A Study on Operational Troubles Due to Ship Motions in the Seto Inland Sea

  SASA Kenji, MIZUI Shinji

  It is important to maintain the regularity and the safety of maritime transportation. For example, many people who live around the Seto Inland Sea have to depend on ferry services. Although many casualties have been reported there, ship motions due to waves have not been studied previously. It is believed that oceanographic conditions are calm in the Seto Inland Sea. In this study, operational troubles of local ferries are researched in detail. First, the interview research was carried out regarding the cancellation of navigation. It is known that the local ferry service has been canceled several times in the winter season to prevent the damage of cargos due to ship motions. Second, the field observations of ship motions were carried out in this winter season. The roll motion becomes remarkable under a west wind of 9-15m/s. Observed results can verify that waves are generated under strong winds or currents, which may cause such ship motions. More research, such as the wave observation, will be necessary in the future.

  Japan Institute of Navigation, Mar. 2006, 日本航海学会論文集, 114(114) (114), 127 - 133, English

  [Refereed]

  Scientific journal


• An analytic study on weather parameters related to restricted visibility due to heavy fog at Geiyo district in Seto Inland Sea

  Kenji Sasa, Tadashi Hibino

  2006, PROCEEDINGS OF THE SIXTEENTH (2006) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, 571 - +, English

  [Refereed]

  International conference proceedings


• A study of difficulties of entering and departing harbours due to wave-induced ship motions

  K Sasa, M Kubo, T Nagai, H Yoneyama, S Shiraishi

  Jun. 2005, INTERNATIONAL JOURNAL OF OFFSHORE AND POLAR ENGINEERING, 15(2) (2), 117 - 124, English

  [Refereed]

  Scientific journal


• 備讃瀬戸航路における速力制限に関する基礎的研究

  MIZUI Shinji, IWASAKI Hiroki, TSUJI Keisuke, SASA Kenji

  In this report, we conduct a questionnaire survey in which we try to find the problems that ship's crews have regarding the speed restrictions along the Bisan Seto East Channel in Seto Inland Sea and whether the speed restrictions are necessary or not. We also conduct prototype simulation within the speed-restricted area of the Bisan Seto East Channel. The survey leads the following findings. (1) It becomes clear that the speed restrictions generate dangerous traffic congestion at the channel and more than 70% of the ship's crews require the improvement. (2) We newly propose a prototype simulation using the Collision Judgement with Fuzzy Inference. (3) This simulation shows that the values of the accumulations of Collision Judgment per day by the Collision Judgement with Fuzzy Inference do not increase when all the ships in the restricted area increase the speed by several knots. Meanwhile, when only one ship increase the speed, the accumulations of Collision Judgement the both crews that picks up the speed and of surrounding ships feel would increase. This shows a contrastive result to the case where all the ships increase the speed.

  Japan Institute of Navigation, Mar. 2005, 日本航海学会論文集, 112(112) (112), 49 - 55, Japanese

  [Refereed]

  Scientific journal


• A Basic Study on Difficulties of Ship Operation Under Restricted Visibility Due to Heavy Fog

  SASA Kenji, MIZUI Shinji, HIBINO Tadashi

  It is very important to provide daily maritime transportation services, especially, in island areas. However, navigation is sometimes cancelled because of heavy fog. Although this is well known among ship operators, the associated situations and problems are not fully understood. In this study, we focus on the difficulties of ship operations under conditions of restricted visibility. First, casualties that occur under conditions of restricted visibility are researched. Then, a nationwide questionnaire was distributed to ship operators to learn the details of the current situations and operational problems. These results were statistically analyzed to demonstrate their operational limits. Moreover, interviews were conducted with a local ferry company to obtain recent cancellation records of navigation. The weather parameters on the dates of cancellations were analyzed and compared in a few cases with the other findings from the questionnaire and the interview research.

  Japan Institute of Navigation, Mar. 2005, 日本航海学会論文集, 112(112) (112), 13 - 20, Japanese

  [Refereed]

  Scientific journal


• Basic research on operational troubles for ships and harbours due to abnormal water levels

  K Sasa, S Mizui, T Nagai, T Hibino

  2005, PROCEEDINGS OF THE FIFTEENTH (2005) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, 3, 720 - 727, English

  [Refereed]

  International conference proceedings


• 荒天時の観測波を用いた船体運動による港外避泊船の安全性評価

  SASA Kenji, NAGAI Toshihiko, SHIRAISHI Satoru, YONEYAMA Haruo, MIZUI Shinji

  台風や低気圧などの荒天を避けるため, 港外避泊していた船舶が走錨・座礁する海難が連続して発生し, 乗組員の人命や船体および貨物の損傷, 油流出による環境汚染が深刻な問題となっている. 本研究では座礁海難の状況を調査し, これまでの研究で未検討の波浪影響に注目した. この結果, 海難時には波浪も顕著な発達が見られ, アンケート調査によっても現状の港外避泊に対する検討の不十分さが様々な側面から明らかとなった. 風および波浪影響を正確に考慮できる錨泊船の船体運動に関する数値シミュレーションを構築し, 外力影響を検証した. この結果, 風と波浪が同時に作用する状況下ではじめて走錨・座礁となる様子が再現できる.

  公益社団法人 土木学会, 2005, 海岸工学論文集, 52(52) (52), 1246 - 1250, Japanese

  [Refereed]

  Scientific journal


• Basic Research on Comparison of Wave Growth between the Pacific Ocean and the Sea of Japan due to Atmospheric Depressions from the Viewpoint of Ship Operation

  SASA Kenji, MIZUI Shinji, NAGAI Toshihiko

  太平洋や日本海など外洋に面した海域に多くの港湾が運用されているが, 台風期だけでなく冬季から春季にかけても船舶の運用が低気圧の影響で困難となることがある. 特に太平洋沿岸では日本の東方海上で発達した低気圧から伝播する波浪が船舶運用に与える影響を詳細に分析した事例は少ない. 本研究では冬季荒天時におけるナウファスの波浪観測データと天気図を様々な角度から分析し, まず日本海側と太平洋側での波浪の発達傾向を比較した. さらに低気圧の進行パターン, 気圧差, 気圧傾度, 位置関係などとの変化傾向と比較を行い, これらの波浪発達との関係についていくつかの知見が得られた.

  Japan Society of Civil Engineers, Jul. 2004, 海洋開発論文集, 20, 833 - 838, English

  [Refereed]

  Scientific journal


• A study on prediction system of critical wave conditions for ship mooring against typhoons

  Kenji Sasa, Masayoshi Kubo, Satoru Shiraishi, Toshihiko Nagai

  Mar. 2004, Coastal Engineering Journal, 46(1) (1), 65 - 91, English

  [Refereed]

  Scientific journal


• 入出港時における沖合観測波形を用いた船体動揺の数値計算および着離岸作業の困難度評価

  笹 健児, 久保 雅義, 永井 紀彦, 米山 治男, 白石 悟, 水井 真治

  外洋性港湾に船舶が入出港するときの安全性について, 前報では大型フェリーが着離岸するときにRollによって作業困難となる状況を定量化した. 本研究では, 港外から港内に至る入出港の全局面で発生する船体動揺を連続的に再現できる数値解析手法の構築を行った結果, 沖合観測波形, 港湾・船型データ, 操船データをもとに着離岸局面を含めた入出港時の船体動揺を実用上十分な精度で再現できることを検証した. さらに着離岸時の作業困難度を定量的に評価できる「着離岸困難度関数」を新たに定義しその有効性を検討した. さらに海域, 港湾, 船型が異なるケースにおいても船体動揺の現地観測を実施し, 入出港の困難さを支配する諸要因について考察した.

  公益社団法人 土木学会, 2004, 海岸工学論文集, 第51巻、pp.1291-1295(51) (51), 1291 - 1295, Japanese


• 荒天運航時のフェリー貨物の安全管理に関する基礎的研究

  2004, 日本航海学会論文集, 第110号、pp.135-142


• Basic research on the safety management of a ferry cargo in rough weather

  G Kobayashi, S Mizui, K Sasa, M Kubo

  2004, PROCEEDINGS OF THE FOURTEENTH (2004) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 4, 3, 540 - 545, English

  [Refereed]

  International conference proceedings


• Basic research on the relationship between wave growth and atmospheric depressions from the viewpoint of ship operations

  K Sasa, S Mizui, T Nagai

  2004, PROCEEDINGS OF THE FOURTEENTH (2004) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, 3, 780 - 787, English

  [Refereed]

  International conference proceedings


• A Study on Numerical Simulation of Ship Motions from the Viewpoint of Evaluation of Difficulties at Entering and Departing Harbours Facing Open Seas

  SASA Kenji, KUBO Masayoshi, NAGAI Toshihiko, YONEYAMA Haruo

  Safety is very important as ships enter and depart from harbours. Ship motions were successfully observed in swells in a previous study, and difficulties were shown to occur during the berthing operation inside the harbour as well as at the harbour entrance. In this study, numerical simulations of ship motions in swells during entrance and departure are recreated for the first time. The accuracy was sufficient for modeling observed ship motions." Moreover, it will be necessary to define the evaluation parameters of the berthing operation. It is constructed and as the "Difficulty of Berthing Function" for ships. The function can be used to quantitatively evaluate the operational difficulty, which should be considered when evaluating harbour tranquility.

  Japan Institute of Navigation, 2004, The Journal of Japan Institute of Navigation, 111(0) (0), 71 - 80, English

  [Refereed]

  Scientific journal


• 外洋性港湾における入出港時の着離岸作業障害に関する研究

  SASA Kenji, KUBO Masayoshi, SHIRAISHI Satoru, NAGAI Toshihiko, CHO Ik Soon, MIZUI Shinji, KOBAYASHI Go

  外洋性港湾で船舶が入出港するときの安全性を検討することは大変重要である. しかし, 現在まで波浪時の船体動揺を考慮し港湾計画・運用で港内静穏度として検討された事例は存在しない. 本研究では大型フェリーが港湾に入出港するときの安全性を対象に船体動揺および波浪の現地観測を実施し, 着離岸するときにRollが顕著となり作業困難となる状況を定量化できた. さらに港外からの波浪伝播と港内の船体動揺の解析モデルを組み合わせた数値モデルを構築し, その精度を検証した. この結果, 実測値をある程度再現できており, 作業障害の主要因は波高0.5～0.6m, 周期10～15s程度のうねり成分が港内で存在するためであることが分かった.

  Japan Society of Civil Engineers, Nov. 2003, 海岸工学論文集, 50(2) (2), 1311 - 1315, Japanese

  [Refereed]

  Scientific journal


• 波浪下での小型船の入港安全指標の開発－入港施設の可能性からの評価－

  KUBO Masayoshi, CHO Ik Soon, SASA Kenji, MIZUI Shinji, KOBAYASHI Go

  In this paper, field experiments are carried out to measure ship motions and waves simultaneously when a small ship enters into harbour under severe weather conditions in winter. Navigator is feeling that safety is in danger on operating the ship when the fore landscape is invisible. So, we develop a new safety index at small ship entering into harbour and it is possible to evaluate visibility or invisibility of the harbour entering facility by analyzing relation between ship motions and wave effects. In the calculation of ship motions, we must convert to coordinate of viewpoint by coordinate diversion. And besides we need to divert to the sea level distribution on track of entering ship from the wave height of wave recorder. As a result, the method of new safety index is expected to reduce a sense of danger by quantitative analysis in case of entering into harbour.

  Japan Institute of Navigation, Sep. 2003, 日本航海学会論文集, 109(109) (109), 17 - 23, Japanese

  [Refereed]

  Scientific journal


• Basic Research on Safety at Entering and Departing Harbours Subjected to Wave Induced Ship Motions

  SASA Kenji, KUBO Masayoshi, SHIRAISHI Satoru, CHO Ik Soon

  Many studies related to port planning focus on the difficulty of steering ships using simulators in winds or currents. In addition, there are many studies on moored ship motions caused by long period waves. These, too, are related to harbour construction and operation. On the other hand, the safety of the entering harbour is researched on ship motions of small ships under wind waves. It is cleared that operators are challenged by ship motions as they enter harbours. However, there is no detailed research on large ships subjected to swells and waves produced by typhoon winds in the Pacific Ocean. In this study, the focus is on an operational problem of a 12, 000 DWT class ferry as it enters and departs a southern Japanese harbour facing the Pacific Ocean. Firstly, the hearing researches are carried out to captains of the ferry line. Field observations are carried out using a new method of observing ship motion. Two problems contribute to the difficulty of steering a ship in swells. A rolling motion occurs inside the harbour, which makes the berthing operation very difficult when a ship approaches the terminal. Finally, we analyze these observed data and consider the new problem of the ship operation at harbours facing to the Pacific Ocean.

  Japan Institute of Navigation, Sep. 2003, 日本航海学会論文集, 109(109) (109), 179 - 189, English

  [Refereed]

  Scientific journal


• New evaluation method of port planning and ship operation from viewpoint of ship motions using new observation system

  K Sasa, M Kubo, S Shiraishi, T Nagai

  Jun. 2003, INTERNATIONAL JOURNAL OF OFFSHORE AND POLAR ENGINEERING, 13(2) (2), 112 - 119, English

  [Refereed]

  Scientific journal


• 外洋性港湾における出入港時諸問題の現地調査 －日本海に面した港湾での波浪特性の解析－

  KUBO Masayoshi, KOBAYASHI Go, MIZUI Shinji, SASA Kenji, NAGAI Toshihiko

  In this study, it is necessary to find out some problems about the ship operation in harbours facing to open seas. At first, the hearing research is carried out for many harbours nationwide to know present operational situations and problems. Then, we research on the operation record of the maritime company in the harbour (H Port) facing to the Sea of Japan. Moreover, wave data are analyzed for one of the observation points of NOWPHAS (Nationwide Ocean Wave information network for Ports and HArbourS) near the harbour when ship operations become impossible in recent years. Some relations can be found between operational records and waves. Therefore, main conclusions are obtained as follows. (1) Operators feel so difficulties for ships on the safety of departing and entering harbours facing to open seas when sea conditions are serious. (2) It is cleared that waves are the most important factor to evaluate the safety of ship-handling in harbours facing to open seas. (3) The most dangerous situation is occurred for entering ships when they are altering course near harbours in following seas. (4) The operation becomes impossible in H Port when significant waves become more than 2.0m and 6s in winter season. (5) When the ship operation becomes difficult in H Port, wave heights grow about wave components in 5-8s at first. Then, wave heights tend to grow about wave components in 8-12s with 2-8hours of time lag in most cases. However, these wave heights grow at the same time in some cases. It is necessary to research on growth patterns of waves in detail when ships cannot operate in the future.

  Japan Institute of Navigation, Mar. 2003, 日本航海学会論文集, 108(108) (108), 21 - 29, Japanese

  [Refereed]

  Scientific journal


• Wave forecast at harbor entrance to support entering ships under rough weather

  M Shinji, K Masayoshi, S Kenji, N Satoru

  2003, PROCEEDINGS OF THE THIRTEENTH (2003) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, Vol.Ⅲ, pp.705-712, 705 - 712, English

  International conference proceedings


• 台風時における港内係留船の係留限界予測に関する研究（第二報）－予測モデルの精度向上および拡張－

  SASA Kenji, KUBO Masayoshi, SHIRAISHI Satoru, NAGAI Toshihiko

  台風時のうねりや風波の伝播による港内の係留問題に対し, 簡易予測モデルの必要性を明らかにした. 予測モデルはカルマンフィルターの理論に基づく台風の逐次予測と予測された台風で発生してから推算点まで伝播する波浪を推算する部分で構成される. また予測モデルを複数の台風が同時に存在する状況でも予測可能となるように拡張した. このモデルにより太平洋に面したA港について, 台風が接近しながら勢力を強める状況や複数の台風が同時に存在する状況にも予測可能であり, さらに他の地点に対してもほぼ十分な精度で予測可能であることが検証された. 一方, 本モデルを港湾での係留限界の予測システムとして構築できる可能性についても検討した.

  Japan Society of Civil Engineers, Nov. 2002, 海岸工学論文集, 49(2) (2), 1421 - 1425, Japanese

  [Refereed]

  Scientific journal


• The Proposition of Prediction System of Ship Mooring Criteria Using Wave and Typhoon Data at Harbours Facing to the Pacific Ocean

  SASA Kenji, KUBO Masayoshi, SHIRAISHI Satoru, NAGAI Toshihiko

  Sep. 2002, Proceedings of the 30th PIANC World Congres, 1322 - 1333, English

  [Refereed]

  International conference proceedings


• A Study on the Prediction of Mooring Criteria as the Berth Operation System

  SASA Kenji, KUBO Masayoshi, SHIRAISHI Satoru, NAGAI Toshihiko

  Mooring problems are still serious issues in port construction and operation. Although there are many studies are carried out about moored ship motions or long period waves, effective countermeasures are not accomplished in most harbours facing to open seas. On the other hand, it is known that operators require the offer of wave information near harbours in detail when sea conditions become serious. In this study, the new numerical model is constructed for the prediction of the mooring criteria. It is based on the theory of Kalman Filter, wave estimation inside typhoons and wave decay as swells. It is characteristic that the prediction model do not need huge amount of input data such as meteorological models. The accuracy is verified for "A Port" facing to the Pacific Ocean when swells or wind waves propagate from typhoons. Moreover, the prediction model applies for other points facing to the Pacific Ocean. This new model makes possible to predict the mooring criteria at 0.5-2 days before under the influence of typhoons. Finally, we propose the berth operation system to monitor the mooring criteria using this prediction model in harbours facing to open seas.

  Japan Institute of Navigation, Sep. 2002, 日本航海学会論文集, 107(107) (107), 127 - 137, English

  [Refereed]

  Scientific journal


• AN ESTIMATION OF LONG-PERIOD OSCILATIONS OF MOORED SHIP BY NUMERICAL SIMULATION

  SHIRAISHI Satoru, YONEYAMA Haruo, SATO Hirakazu, SASA Kenji

  It is important in berth planning and port operation to be accurately familiar with moored ship motions correctly in especially long period component, especially at ports facing the open sea. The phenomenon of moored ship oscillations has been studied for decades by model experiments, field observations and numerical simulations. This paper shows the comparison of numerical simulation result and field observations to discuss how we get more accurate result by the numerical simulations on ship motions. Major unknown factors for surging in the numerical simulations are the condition of mooring ropes and damping factor. Then, we discuss on the effect of the characteristics of mooring system and surge damping factor.

  Japan Society of Civil Engineers, 2002, PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN, 18(18) (18), 137 - 142, Japanese

  [Refereed]

  Scientific journal


• 台風時における港内係留船の係留限界予測に関する研究

  SASA Kenji, KUBO Masayoshi, TAKAHASHI Rinya, SHIRAISHI Satoru, NAGAI Toshihiko

  Japan Society of Civil Engineers, Nov. 2001, 海岸工学論文集, 48(2) (2), 1351 - 1355, Japanese

  [Refereed]

  Scientific journal


• 船体運動測定装置を活用した全天候型海上輸送システム構築へ向けての基礎的研究

  SASA Kenji, KUBO Masayoshi

  In harbours facing to the open sea, long breakwaters tend to be built to decrease wave heights. Also, it is cleared that the influence of moored ship motions has to be considered. On the other hand, ship motions at harbour entrances due to waves are one of the most serious problems in ship handling. However, ship motions near harbour entrances are not discussed and observed so much. Therefore, it is necessary to research on ship motions offshore and near harbour entrance. In this study, we observe ship motions during the navigation, entering to and departing from harbours. Ship motions are measured by the new type of measurement equipment consisted of GPS, optical fiber gyro and gyro compass. Observed data at the departure from the harbour shows that the rapid growth of ship motions can be recognized as the important factor, which causes the difficulty of ship handling near the harbour entrance. So, it is verified that harbours should be constructed and operated based on the numerical influence of ship motions due to waves near harbour entrances and offshore.

  Japan Society of Civil Engineers, Jun. 2001, 海洋開発論文集, 17, 235 - 240, Japanese

  [Refereed]

  Scientific journal


• Basic Research on the Relation Between Mooring Criteria and Typhoons at Harbour Facing to the Pacific Ocean

  SASA Kenji, KUBO Masayoshi, SHIRAISHI Satoru, NAGAI Toshihiko

  Mooring troubles due to moored ship motions in a harbour facing the open sea are very serious problem from the point of view of the port operation. Some studies about a wave prediction are carried out, however, the accuracy of the prediction isn't still enough exact, especially in case of a rapid wave growth at stormy weathers. In this study, we focus on a harbour facing the Pacific Ocean, and research on mooring troubles which are happened in 1997-1998. Furthermore, observed wave data by NOWPHAS system and typhoon data are analyzed. Thus, we consider the relations among mooring troubles, observed wave conditions, and typhoons from the point of view of the mooring criteria.

  Japan Institute of Navigation, Mar. 2001, 日本航海学会論文集, 104(104) (104), 197 - 206, English

  [Refereed]

  Scientific journal


• Basic research on frequency properties of long period waves at harbour facing to the Pacific Ocean

  K Sasa, M Kubo, S Shiraishi, T Nagai

  2001, PROCEEDINGS OF THE ELEVENTH (2001) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL III, Vol.Ⅲ, pp.537-544, 593 - 600, English

  International conference proceedings


• Basic Research on the Prediction of the Wave Growth at Harbours Facig to the Pacific Ocean（共著）

  2001, Proceeding of the 11th International Offshore and Polar Engineering Conference, Vol.Ⅲ, pp.593-600


• Basic research on the prediction of the wave growth at harbour facing to the Pacific Ocean

  K Sasa, M Kubo, S Shiraishi, T Nagai

  2001, PROCEEDINGS OF THE ELEVENTH (2001) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL III, 3, 537 - 544, English

  [Refereed]

  International conference proceedings


• Basic research on frequency properties of long period waves at harbour facing to the Pacific Ocean

  K Sasa, M Kubo, S Shiraishi, T Nagai

  2001, PROCEEDINGS OF THE ELEVENTH (2001) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL III, 3, 593 - 600, English

  [Refereed]

  International conference proceedings


• 信頼性手法による係留船舶の動揺評価に関する基礎的研究

  SASA Kenji, SHIRAISHI Satoru

  Nov. 2000, JCOSSAR2000論文集, 571 - 578, Japanese

  [Refereed]

  Scientific journal


• Reliability Assessment for Motions and Mooring Forces on Moored Ship in a Harbor

  SHIRAISHI Satoru, SASA Kenji

  Jul. 2000, Proceedings of the 8th ASCE Conference on Probabilistic Mechanics and Structural Reliability, English

  [Refereed]

  International conference proceedings


• 長周期船体動揺の数値計算による再現性に関する研究

  SHIRAISHI Satoru, KUBO Masayoshi, SAKAKIBARA Shigeki, SASA Kenji

  Nov. 1999, 海岸工学論文集, 46(2) (2), 861 - 865, Japanese

  [Refereed]

  Scientific journal


• 船体動揺計算における港内副振動の考慮方法と粘性減衰係数の評価

  FUJIHATA Sadao, HATA Sadakatsu, NAKAYAMA Shinichi, MORIYA Yoichi, SEKIMOTO Tsunehiro, IKENO Masaaki, SASA Kenji

  Japan Society of Civil Engineers, Nov. 1999, 海岸工学論文集, 46(2) (2), 866 - 870, Japanese

  [Refereed]

  Scientific journal


• Numerical Estimation on Low-Frequency Ship Oscillations in Harbors and its Application on Port Facility Design

  SHIRAISHI Satoru, YONEYAMA Haruo, SAKAKIBARA Shigeki, SASA Kenji

  Sep. 1999, Proceedings of the 12th International Harbour Congress, 389 - 398, English

  [Refereed]

  International conference proceedings


• 外洋性コンテナターミナルの係留設備の設計および運用に関する基礎的研究

  SHIRAISHI Satoru, SASA Kenji

  Moored ship motions due to long period waves become the serious problem, those phenomenon are happened in harbors which faces the open sea. Container terminals have been built in harbors at inside bay by now, however, some container terminals are planned and built in a harbor which faces the open sea area because of container carriers of larger sizes. Container carriers have more serious limit values of cargo handling than bulk carriers, tankers, etc. In this study, firstly, we research about the operation situation of container terminals which are working now and operational plans of new container terminals that which faces the open sea. Secondly, we examine about the design of mooring equipment of container terminals by using numerical simulations of moored ship motions considering long period waves, swells and winds. At last, we consider about the facility design of container terminals which faces open sea in the future.

  Japan Society of Civil Engineers, Jun. 1999, 海洋開発論文集, 15, 89 - 94, Japanese

  [Refereed]

  Scientific journal


• A study on numerical simulation methods to reproduce long-period ship motions

  S Shiraishi, M Kubo, S Sakakibara, K Sasa

  1999, PROCEEDINGS OF THE NINTH (1999) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL III, 1999, 3, 536 - 543, English

  [Refereed]

  International conference proceedings


• A Study on the Simplified Estimation and the Evaluation Method of Subharmonic Motions in Sway Mode

  KUBO Masayoshi, SASA Kenji

  Dec. 1998, The Journal of Japan Institute of Navigation, Commemorative Issue of 50th Anniversary, 51 - 60, English

  [Refereed]

  Scientific journal


• Basic research on primary factors that controls mooring criteria - In case of ports facing to open sea with swells and seasonal winds

  M Kubo, M Tsugane, K Sasa, S Sakakibara

  1998, PROCEEDINGS OF THE EIGHTH INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, Vol.Ⅲ, pp.603-610, 603 - 610, English

  International conference proceedings


• A Study on the Simplified Estimation and the Evalution Method of Subharmonic Motions in Sway Mode（共著）

  1998, The Journal of Japan Institute of Navigation, Commemoerative Issue of 50th Anniversary, pp.51-60


• Basic Research about an Operation at a Sea Berth in Open Sea and a Safety of Moored VLCC

  KUBO Masayoshi, TSUGANE Masanori, SASA Kenji, NARITA Toyotaka, SAKAKIBARA Shigeki

  Japan Institute of Navigation, 1998, NAVIGATION, 136, 19 - 25, Japanese


• Basic research on primary factors that controls mooring criteria - In case of ports facing to open sea with swells and seasonal winds

  M Kubo, M Tsugane, K Sasa, S Sakakibara

  1998, PROCEEDINGS OF THE EIGHTH INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, 3, 603 - 610, English

  [Refereed]

  International conference proceedings


• Basic research on advanced safety for offshore sea berth in open sea and berth operation support system

  M Kubo, M Tsugane, K Sasa, T Narita, S Sakakibara

  1998, PROCEEDINGS OF THE EIGHTH INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL 3, 3, 596 - 602, English

  [Refereed]

  International conference proceedings


• 数値計算手法が長周期波作用下における長周期船体動揺へ及ぼす影響について

  KUBO Masayoshi, SASA Kenji, SHIRAISHI Satoru, SAKAKIBARA Shigeki

  Japan Society of Civil Engineers, Nov. 1997, 海岸工学論文集, 44(1) (1), 236 - 240, Japanese

  [Refereed]

  Scientific journal


• 日本海に面した港湾での高波高の発生予測に関する基礎的研究

  KUBO Masayoshi, KOMUNE Tae, SASA Kenji

  In ports and harbors facing to the open sea, mooring ships have sometimes encountered severe wave condition in the winter, then the mooring ropes and fenders are broken. As the results, the accident of ship body damage has happened. In order to avoid such accidents, we should set the mooring criteria for the ship shifting to outside of the harbor. For the target N-port facing to the Sea of Japan, the critical offshore wave hight is known to be 5m by our previous research, so we try to forecast the wave height before 2 or 4 hours earlier. We propose several high wave forecasting methods using waves, winds and both data. If we use the 5 parameters method of wind and wave, we can forecast the critical conditions with 77% accuracy and 12 parameters method of wind, then 91% accuracy.

  Japan Institute of Navigation, Sep. 1997, 日本航海学会論文集, 97(97) (97), 73 - 83, Japanese

  [Refereed]

  Scientific journal


• 外洋性シーバース運用の安全性向上と運用支援システムに関する基礎的研究

  KUBO Masayoshi, TSUGANE Masanori, SASA Kenji, NARITA Toyotaka, SAKAKIBARA Shigeki

  Suspending of cargo handling caused by moored ship motions is serious problem at sea berths facing to open sea area. In this paper, we focus on a tanker sea berth facing to the Pacific Ocean. And we research about the berth operation of the sea berth firstly. Secondly, we measure and analyze the wind waves and swell data at the berth. We simulate mooring ship motions under these waves and winds, then we compared with the hearing result from the berth master and the simulation result. Finally, we propose a berth operation support system for a safe berth operation.

  Japan Society of Civil Engineers, Jun. 1997, 海洋開発論文集, 13, 37 - 42, Japanese

  [Refereed]

  Scientific journal


• 係留限界判断のための港湾波浪統計利用に関する基礎的研究

  KUBO Masayoshi, TSUGANE Masanori, KOMUNE Tae, SASA Kenji, SAKAKIBARA Shigeki

  Recently long period waves and sudden growing waves cause breakage of mooring ropes and over compression of fenders and damage moored ships. In this paper we study on determining the judgement of survival mooring conditions for a specific port by using the wave statistics in ports and harbors and weather data. The obtained results are summarized as follows : (1) By using the existing wave statistics, the useful characteristics for judgement of survival mooring conditions for the port is obtained. (2) The wave height is the most important for the judgement of survival conditions. So we define new parameters as a maximum wave height and a growth rate of wave height in order to clarify the relation between wave heights and atmospheric pressures. (3) Studying the correlations between above new parameters, the characteristics of wind and moving low pressures, we can obtain available informations for judgement of survival mooring conditions. (4) Since there exists the time difference between the neighboring harbors when the maximum wave heights happen, it is useful to exchange the wave height informations to judge the mooring conditions.

  Japan Institute of Navigation, Mar. 1997, 日本航海学会論文集, 96(96) (96), 303 - 311, Japanese

  [Refereed]

  Scientific journal


• 係留限界を支配する諸要因に関する基礎的研究 －うねりと季節風が卓越する海域に立地する港湾の場合－

  KUBO Masayoshi, TSUGANE Masanori, SASA Kenji, SAKAKIBARA Shigeki

  A lot of studies about mooring ship motions have done in recent decades, but they are focused on cargo handling criteria. At some ports in open sea, mooring ships move so hard and sometimes mooring lines or fenders are broken. So, when we think about mooring criteria, we have to consider a lot of parameters. In this paper, we study about these parameters and we pick up some cases of mooring accidents at the harbor face to Pacific Ocean. And we find out the results as follows : (1) We can't argue about the mooring criteria correctly if we focus only on ship motions. (2) We can clear up the relation between cargo handling criteria and the mooring criteria. (3) Mooring accidents tend to take place in winter season than other seasons in these cases. (4) In most of those accident cases, mooring ships should shift to offshore earlier stage. (5) The required time length when ships shift to offshore depends on the ship type, the cargo handling way, etc. (6) The difficulty of wave prediction makes so hard to make out mooring criteria. (7) We have to consider long period wave in case of considering the mooring criteria. (8) There are trade off relations between the safety of mooring ship and the berth efficiency. (9) It is necessary to grasp the effect of moored ship motions by wave and wind correctly, if we want to avoid mooring accidents.

  Japan Institute of Navigation, Mar. 1997, 日本航海学会論文集, 96(96) (96), 313 - 322, Japanese

  [Refereed]

  Scientific journal


• 外洋に面した海域に立地する港湾の係留問題について

  KUBO Masayoshi, TSUGANE Masanori, SASA Kenji, SAKAKIBARA Shigeki

  In some ports facing to open sea, moored ships sometimes move so hard that cargo handling or mooring becomes difficult, and the mooring lines or fenders have broken in serious case. Then we focus on the wave and wind conditions of inside and outside of a port facing to Sea of Japan where moored ships move hard in winter and find the existence of the "long period wave". One year wave data of inside and outside of other port facing to East China Sea are observed and the spectrum analysis of them is done, and we ensure the existence of long period wave exist and its energy increases inside of the port. Firstly, we simulate the phenomenon of moored 60, 000 DWT bulk ship motions using wave data included "long period wave". Secondly, we change mooring methods and simulate the ship motion at the same condition, and then compare the ship motions, mooring line tensions and fender reaction forces. As the result, we consider the effect of the better mooring methods in ports facing to open sea in case of stormy weather.

  Japan Institute of Navigation, Mar. 1997, 日本航海学会論文集, 96(96) (96), 259 - 267, Japanese

  [Refereed]

  Scientific journal


• The Ideal Image of Harbors Facing to Outside Bay(Port and Harbor)

  SASA Kenji

  Japan Institute of Navigation, 1997, NAVIGATION, 132, 32 - 41, Japanese


• 係留船のSWAYモードにおけるサブハーモニック・モーションについて

  KUBO Masayoshi, SASA Kenji

  Nov. 1994, 海岸工学論文集, 41(2) (2), 941 - 945, Japanese

  [Refereed]

  Scientific journal


• 係留船のSWAYモードにおけるサブハーモニック・モーションの評価方法に関する研究

  KUBO Masayoshi, SASA Kenji

  Sep. 1994, 日本航海学会論文集, (91) (91), 11 - 19, Japanese

  [Refereed]

  Scientific journal


• Simplified Estimation of Subharmonic Motions

  KUBO Masayoshi, SASA Kenji

  Aug. 1994, Proceedings of the International Symposium Waves—Physical and Numerical Modeling, 3, 1315 - 1323, English

  [Refereed]

  International conference proceedings


• 湾内港湾と湾外港湾の年間稼働率に関する研究

  KUBO Masayoshi, SASA Kenji

  In Japan, large main ports are located in the area where sea conditions are good and they are near the big cities. But recently it is pointed out that this area is not necessarily desirable as harbours in all aspects. The Ministry of Transport is planning to build new ports outside bay. But the outside ports have serious natural conditions than inside ones. Then we simulate one-year workabilities by using the harbour tranquility and a moored ship motion. We introduced the "ASYMMETRICAL AMPLIFICATION FUNCTION", which explains easily a phenomenon of Subharmonic Motion. The obtained results can be summarized as follows : (1) When we simulate one-year workability of harbours, we have to consider the wave height in a harbour, ship entry into port, and moored ship motions. (2) The maximum value of the amplitude of Subharmonic Motion X_ can be expressed as the sum of the maximum value of amplitude in case of free vibration X'_ and the amplitude in case of symmetrical mooring ζ_. (3) We consider the Subharmonic Motion. Then we introduce AS (T) : "ASYMMETRICAL AMPLIFICATION FUNCTION" which can explain this complicated phenomenon easily. The value of AS (T) increase rapidly from about 40 of spring constant ratio. AS (T) is 1 at harbours inside bay as the incident wave period is short, but it becomes several times as the wave period is long at harbours outside bay.

  Japan Institute of Navigation, Mar. 1994, 日本航海学会論文集, 90(90) (90), 99 - 109, Japanese

  [Refereed]

  Scientific journal


• Simplifed Estimation of Subharmonic Motions（共著）

  1994, Proceedings of the International Symposium Waves-Physical andNumerical Modeling, Vol.3, pp.1315-1323


• 交通機関別の速力逓減に関する基礎的研究

  KUBO Masayoshi, SASA Kenji, TSUJI Seiki, MUTA Yukinori

  In recent decades the pace of our life style has become faster, so, the short-time transportation is becoming inevitable. Then we focused on the slow down process of traffics. In this paper, firstly, we carried out some experiments about the slow down patterns of 3 different traffics (ship, car and train) and obtained these slow down curves. Then we compare the amount of the loss of time in the slow down process with these traffics by introducing the "DELAY FUNCTION" which is an inverse of the "velocity function" as follows : S'=∫Ddx =∫(dt/dx)dx =T where dt/dx is the DELAY FUNCTION D, x is a distance, and T is an elapsed time. Then the area under the curve, S, means the amount of time, T. Thus, we know the loss of time in the slow down process. Finally, we obtained the results as follows : (1) In the slow down curves of velocity they look same near 0.1 of d/d_0, but in the DELAY curves there are noticeable differences in this area. (2) The amount of time in the slow down process can be obtained by integrating the DELAY FUNCTION. (3) To evaluate the slow down process, it is very important to reveal the area where d/d_0 is near 0 to 0.1. (4) T also depends on the distance of the slow down process and the working speed of each traffic. (5) T of the ship is the largest of all cases. (6) The slow down curves must be raised upwards near the origin. (7) In the slow down curves, all of them show typical patterns with bench type portion near 0.5 of d/d_0.

  Japan Institute of Navigation, Mar. 1993, 日本航海学会論文集, 88(88) (88), 161 - 169, Japanese

  [Refereed]

  Scientific journal

• Optimal Ship Routing and Cargo Condensation in Container Ships

  Kenji Sasa

  Lead, Apr. 2025, 日本マリンエンジニアリング学会誌, 60(2) (2), 53 - 57, Japanese

  [Refereed][Invited]

  Introduction scientific journal


• Numerical Algorithm to Generate the Time Series of Wind and Wave Disturbances, and Its Application for Ship Maneuverability

  牧敦生, 松井貞興, 脇田康希, 澤田涼平, 笹健児, DOSTAL Leo

  2024, 日本船舶海洋工学会講演会論文集(CD-ROM), (38) (38)


• Wind Process Generation Algorithm for Examining Autonomous Operating Systems of Ships (2nd Report)

  牧敦生, 丸山湧生, DOSTAL Leo, 笹健児, 澤田涼平, 澤田涼平, 脇田康希, 酒井政宏, 梅田直哉

  2022, 日本船舶海洋工学会講演会論文集(CD-ROM), (34) (34)


• Evaluating safety at sea by comparing numerical accuracies of ship motions

  Sasa Kenji, Terada Daisuke, Shiotani Shigeaki, Wakabayashi Nobukazu

  Kobe University, Mar. 2013, Journal of maritime researches, 3(1) (1), 63 - 84, Japanese

  Link to Kobe Univ. Repository (Kernel)


• Time series analysis for ship motions caused by Tsunami

  寺田 大介, 笹 健児, 若林 伸和

  日本船舶海洋工学会, Nov. 2011, 日本船舶海洋工学会講演会論文集, (13) (13), 41 - 44, Japanese


• A Study on Operational Performance of Cargo Carrier from Viewpoint of Safety and Efficiency of International Maritime Transport

  笹 健児, 寺田 大介, 塩谷 茂明

  日本船舶海洋工学会, Nov. 2011, 日本船舶海洋工学会講演会論文集, (13) (13), 303 - 306, Japanese


• A Consideration on Casualties of Ferries in Heavy Sea Using Wave and AIS Database

  笹 健児, 若林 伸和, 小林 英一

  日本船舶海洋工学会, May 2011, 日本船舶海洋工学会講演会論文集, (12) (12), 379 - 382, Japanese


• Safety Evaluation of Cutter Training at Sea with Strong Tidal Currents and Winds

  Sasa Kenji

  When any teaching staffs have to be in charge of the subject they've never experienced,elaborate preparation will be required until the new semester starts. However,it is difficult to obtain these kinds of information in sea training under local weather conditions. In this paper,the author considers an improvement of the cutter training through his teaching experience in college.Firstly,descriptions and requirements of the training are summarized to implement lessons every week.It is famous that tidal current's speed is very fast near the training sea area.Then,weather and oceanographic database is analyzed from April to October.This reveals that wind speeds sometimes rapidly increased in spring seasons,so it is more difficult to predict.Tide levels have been observed for 3 months to simulate spatial distribution of tidal currents around the training sea.Numerical simulations of tidal currents are implemented to verify the spatial distribution of them.Finally,the information system of safety judge is considered to operate the sea training as the new education tool.

  Institute of National Colleges of Technology,Japan, Mar. 2011, Japanese colleges of technology education journal, 34, 203 - 208, Japanese


• Safety Evaluation of Coastal Waters from Viewpoint of Anchoring Ship Motions in Offshore Harbour Refugee

  笹 健児, Incecik Atilla

  日本船舶海洋工学会, Jun. 2010, 日本船舶海洋工学会講演会論文集, (10) (10), 335 - 338, Japanese


• Safety evaluation of berthing into harbours under strong currents from viewpoint of ship motions

  笹 健児, 日比野 忠史, Kim Kyunghoi

  土木学会, Oct. 2009, Journal of coastal engineering, JSCE, 56, 1301 - 1305, Japanese


• 校門指導・交通指導の導入による学生指導の取り組みについて

  2005, 高専教育, 第28号、pp.625-630


• 17. A Study on Ship Refuge from Harbor at Large Scale Tsunami

  MIZUI Shinji, SASA Kenji, KUBO Masayoshi

  At first, we research the position of Japanese ports for dangerous cargoes. After the research, first step questionnaire by fax is carried out. The time for releasing the connection of oil transporting equipment between ship and land and the time to escape from the mooring berth to the outer part of the ports are investigated. Using this basic research, precise questionnaire is carried out on mooring and cargo handling equipments for 81 berths such as crude oil refineries, electric power plants and shipping companies.

  地域安全学会事務局, 2004, 地域安全学会梗概集, (14) (14), 61 - 64, Japanese


• A Simple Mooring Criteria Prediction Method for Moored Vessels in Harbours from Wave Conditions Due to Typhoons

  白石 悟, 永井 紀彦, 笹 健児

  港湾空港技術研究所, 2003, Technical note of the Port and Airport Research Institute, No.1043, 32p.(1043) (1043), 1 - 32, English


• Effect of Sail on Anchoring of Yuge-Maru

  Takaoka Shunsuke, Toyota Toshihiko, Iwasaki Kazushi, Murata Kou, Sasa Kenji, Kubo Masayoshi

  Yuge National College of Maritime Technology, 28 Feb. 2002, 弓削商船高等専門学校紀要, 24, 17 - 22, Japanese


• The Relation Analysis Between Typhoons and Waves on the View of Ship Mooring Criteria in Harbours

  白石 悟, 永井 紀彦, 笹 健児

  港湾空港技術研究所, 2001, Technical note of the Port and Airport Research Institute, No.1011, 36p.(1011) (1011), 1 - 36, English


• An Analysis on the Properties and Spectrum Shape of Long Period Waves at a Port facing to the Pacific Ocean

  白石 悟, 永井 紀彦, 笹 健児

  港湾空港技術研究所, 2001, Technical note of the Port and Airport Research Institute, No.1012, 33p.(1012) (1012), 1 - 33, English


• A Basic Study on the Construction of Weather-Proof Maritime Transportation System（共著）

  2001, Proceedings of PACON 2001


• A Study on Estimation Methods of Spectrums of Long Period Waves（共著）

  2001, Proceedings of PACON2001


• A Study on Relations Between Typhoons, Long Waves and Mooring Criteria（共著）

  2001, Proceedings of PACON2001


• 信頼性手法による船舶の荷役および係留の安全性評価に関する基礎的検討（共著）

  2000, 港湾技研資料, No.956, 44p.


• 係留船舶の長周期動揺の各種数値計算手法による再現性に関する比較検討（共著）

  笹 健児, 白石 悟, 榊原 繁樹

  国土交通省港湾技術研究所, 1999, 港湾技研資料, No.931 80p.(931) (931), 1 - 80, Japanese


• A Study on the Simplifed Estimation and the Evalution Method of Subharmonic Motions in Sway Mode（共著）

  1998, The Journal of Japan Institute of Navigation, Commemoerative Issue of 50th Anniversary, pp.51-60


• Change of Harbour Tranquility by the Second Port Island in Kobe

  KUBO Masayoshi, SAITO Katsuhiko, SASA Kenji

  Japan Institute of Navigation, 1993, NAVIGATION, 第117号, pp.72-79, 72 - 79, Japanese

• GHG排出量ゼロに向けた船舶流体力学の現状と展望

  川北千春, 川島英幹, 新郷将司, 寺田大介, 上野道雄, 毛利隆之, 白石耕一郎, 木村校優, 松田識史, 笹 健児, 折原秀夫, 日野孝則, 大橋訓英, 一ノ瀬康雄, 金井 健, 佐藤 圭, 犬飼泰彦, 蓮池伸宏, 平田宏一, 金丸 崇, 日夏宗彦

  Joint work, 第5章（pp.69-111）, 日本船舶海洋工学会推進・運動性能研究会, Dec. 2020


• 商船学の数理 基礎と応用

  SASA KENJI, SHIMIZU SEIJI, YAMAGUCHI SHINYA, FUTAMURA AKIRA, KAMATA KOICHI, CHIBA HAJIME

  Joint work, 海文堂書店, Mar. 2014, Japanese

  Textbook


• 海上輸送の三原則

  ABE AKIHISA, UCHIDA MAKOTO, SASA KENJI, SHIOTANI SHIGEAKI, SHIMADA YOICHI, SHOJI KENICHI, SUZUKI YUSUKE, TAKAYAMA ATSUYOSHI, DAN TOMOHISA, 崔 栄珍, TERADA DAISUKE, MIMURA HARUO, YOSHIDA SHIGERU, WAKABAYASHI NOBUKAZU

  Joint work, 海文堂書店, Jul. 2013, Japanese

  Scholarly book


• 海上貨物輸送論

  KUBO MASAYOSHI, SAITO KATSUHIKO, MIZUI SHINJI, ASAKI KENJI, SASA KENJI

  Joint work, 成山堂書店, Mar. 2007, Japanese

  Scholarly book

• 実海域における機関負荷の周波数特性から見た荒天航海時の意図的減速の判断

  前田真穂, 笹健児, 寺田大介

  日本船舶海洋工学会・第27回推進・運動性能研究会, Mar. 2024, Japanese

  Oral presentation


• ランキンパネル法による transom stern を持つ低速肥大船 周りの波動場の計算について

  嶋悠馬, 笹健児, 岩下英嗣

  日本船舶海洋工学会・第29回推進・運動性能研究会, Oct. 2024, Japanese

  Oral presentation


• 20,000TEUコンテナ船の実船データおよび AIS データから見たスエズ運河の航行状況に関する考察

  宮原貫太, 笹健児

  日本船舶海洋工学会・第29回推進・運動性能研究会, Oct. 2024, Japanese

  Oral presentation


• 北太平洋における荒天航海時の船舶の安全航行およびうねりの伝搬特性に関する一考察

  正垣智也, 笹健児, LEE SANGWON

  日本船舶海洋工学会・第29回推進・運動性能研究会, Oct. 2024, Japanese

  Oral presentation


• Data Driven Studies for Real Ships in Actual Seas

  Kenji Sasa

  Joint Seminar of Ship Data Science in KMOU, Oct. 2024, English

  Invited oral presentation


• 肥大船に対する波浪中抵抗増加の差異に関する比較考察察

  嶋悠馬, 笹健児

  日本船舶海洋工学会・第27回推進・運動性能研究会, Mar. 2024, Japanese

  Oral presentation


• 太平洋での荒天航海時に遭遇した気象変化およびうねり特性に関する一考察

  正垣智也, 笹健児, Sang-Won Lee

  日本船舶海洋工学会・第26回推進・運動性能研究会, Nov. 2023, Japanese

  Oral presentation


• 実海域における主機関負荷変動の時変自己回帰モデル解析について

  前田真穂, 笹健児

  日本船舶海洋工学会・第26回推進・運動性能研究会, Nov. 2023, Japanese

  Oral presentation


• Dynamic Analysis of Lashed Trailers in Ferry under Rough Sea Voyages

  Kenji Sasa

  QiR (Quality in Research) 2023 Conference, Bali, Oct. 2023, English

  [Invited]

  Keynote oral presentation


• 実海域における荒天航海時の主機関負荷の周波数特性について

  前田真穂, 笹健児

  日本船舶海洋工学会・第25回推進・運動性能研究会, Jul. 2023, Japanese

  Oral presentation


• 細⻑船モデルごとにおける船首尾端の形状影響による流体力係数および抵抗増加の数値比較と考察

  嶋悠馬, 笹健児

  日本船舶海洋工学会・第25回推進・運動性能研究会, Jul. 2023, Japanese

  Oral presentation


• Numerical Simulation of Cargo Lashing of Trailers for Coastal Ferry under Rough Seas

  Kenji Sasa, Sang-Won Lee, Ryotaro Shimada

  日本船舶海洋工学会 第22回推進・運動性能研究会, Jul. 2022, Japanese

  Oral presentation


• 日本近海を航行する内航コンテナ船の実海域性能から見た燃費特性について

  笹健児

  日本船舶海洋工学会関西支部 KFR・KSSG共催シンポジウム 実船モニタリングの最前線, Mar. 2022, Japanese

  [Invited]

  Nominated symposium


• 車両貨物から見た荒天航海時における大型フェリーの安全性評価

  島田遼太郎, 笹健児

  日本船舶海洋工学会 第20回推進・運動性能研究会, Oct. 2021, Japanese

  Oral presentation


• Evaluation of Time Series Ship Motions in Actual Seas in Global Sea Areas

  Waskito, K.T, Sasa, K, Chen, C

  日本船舶海洋工学会 第20回推進・運動性能研究会, Oct. 2021, English

  Oral presentation


• Risk Assessment of Anchoring Ship Motions as a Part of Optimal Ship Routing Offshore Harbor under Rough Sea Conditions

  Lee, S.W, Sasa, K, Chen, C

  日本船舶海洋工学会 第20回推進・運動性能研究会, Oct. 2021, English

  Oral presentation


• 実船の遭遇風速・風向の時系列データのシミュレーション環境下での再現法についての研究

  牧敦生, 丸山湧生, Leo Dostal, 酒井政宏, 澤田涼平, 笹健児, 梅田直哉

  日本船舶海洋工学会 第20回推進・運動性能研究会, Oct. 2021, Japanese

  Oral presentation


• Development of Optimal Ship Routing and Evaluation of Maneuvering Difficulty with Onboard Measuring

  Sasa, K

  14th Baska GNSS Conference, May 2021, English

  [Invited]

  Invited oral presentation


• 実海域性能モニタリング（第5章）

  笹 健児, 折原 秀夫

  日本船舶海洋工学会推進;運動性能研究会シンポジウム, Dec. 2020, Japanese

  [Invited]

  Invited oral presentation


• Numerical Simulation and Validation of Maneuvering Difficulty in Rough Sea Voyage in the Southern Hemisphere for 28,000DWT Bulk Carrier

  景 乾峰, 笹 健児, 陳 辰, 安川宏紀

  日本船舶海洋工学会第16回推進・運動性能研究会, Jun. 2020, English

  Oral presentation


• 気象海象中における船速低下の高度化を考慮した最適運航シミュレーションの構築と実船データによる再現検証

  藤松拓也, 笹 健児, 陳 辰, 庄司るり

  日本船舶海洋工学会第16回推進・運動性能研究会, Jun. 2020, Japanese

  Oral presentation


• 実船モニタリングデータを用いた縦揺れの確率分布の予測

  寺田 大介, 小竿 誠, 田中 良和, 笹 健児

  日本船舶海洋工学会 第14回推進・運動性能研究会, Nov. 2019, Japanese, Domestic conference

  Oral presentation


• Evaluation and simulation of ship maneuvering motion in rough seas based on-board measurement system

  JING Qianfeng, SASA Kenji, CHEN Chen, YASUKAWA Hironori

  日本船舶海洋工学会 第14回推進・運動性能研究会, Oct. 2019, English, Domestic conference

  Oral presentation


• 荒天航海時における風の再現性を支配するパラメーター についての一考察

  CHEN CHEN, SASA KENJI, OHSAWA TERUO

  日本船舶海洋工学会第13回推進・運動性能研究会, Jun. 2019, English, 神戸大学海事科学研究科, Domestic conference

  Oral presentation


• Survey and data analysis on deliberate speed in rough sea conditions

  SASA KENJI, CHEN CHEN

  日本船舶海洋工学会 第77回実海域性能研究会, Mar. 2019, Japanese, 大島造船所（長崎県西海市）, Domestic conference

  Oral presentation


• Comparison of wave estimation in each global weather database and accuracy of air model

  CHEN CHEN, SASA KENJI

  日本船舶海洋工学会 第77回実海域性能研究会, Mar. 2019, English, 大島造船所（長崎県西海市）, Domestic conference

  Oral presentation


• 荒天航海時に遭遇する風波特性の再現性に関する比較検 証－大気計算の境界条件およびデータ同化が再現精度に 及ぼす影響－

  YONEMURA TAISHI, CHEN CHEN, SASA KENJI, OHSAWA TERUO

  日本船舶海洋工学会 第12回推進・運動性能研究会, Feb. 2019, Japanese, 横浜国立大学 理工学部 船舶海洋工学棟（N10-1）302 室, Domestic conference

  Oral presentation


• フェリー航海時における船体運動および係留力の動的影 響を考慮した車両貨物の安全性評価について

  TAKAGAKI TORU, SASA KENJI

  日本船舶海洋工学会・第12回推進・運動性能研究会, Feb. 2019, Japanese, 横浜国立大学 理工学部 船舶海洋工学棟（N10-1）302 室, Domestic conference

  Oral presentation


• 実海域データから見た荒天航海時の意識的減速について －アンケート調査および減速パターンの評価モデルにつ いて－

  TAKEUCHI KAICHI, SASA KENJI, CHEN CHEN

  日本船舶海洋工学会 第11 回 推進・運動性能研究会, Oct. 2018, Japanese, 長崎タクシー会館, Domestic conference

  Oral presentation


• 荒天航海時における風波の再現性を支配するパラメータ ーについての一考察‐気象データベースおよび力学モデ ルごとの再現性比較－

  CHEN CHEN, SASA KENJI, YONEMURA TAISHI, OHSAWA TERUO

  日本船舶海洋工学会 第11 回 推進・運動性能研究会, Oct. 2018, English, 長崎タクシー会館, Domestic conference

  Oral presentation


• 実海域データから見た荒天航海時の意識的減速について－加速度および主機関係のパラメーターから見た考察－

  SASA KENJI, TAKEUCHI KAICHI, CHEN CHEN, MIWA TAKASHI

  日本船舶海洋工学会第10回推進運動性能研究会, Jun. 2018, Japanese, 大阪府立大学I-siteなんば, Domestic conference

  Oral presentation


• Some Properties on Rough Sea Navigation for a Bulk Carrier —Comparison in Sea Area and Seasons—

  SASA KENJI

  The 72nd Symposium of Research Society of the Ship Performance in Actual Seas, Apr. 2016, Japanese, Tokyo University of Marine Science and Technology, Domestic conference

  Oral presentation


• Numerical Simulation of Wind Waves in Rough Seas using Different Wind Inputs -Comparison and Verification-

  LU LI-FENG, SASAKI WATARU, SASA KENJI

  The 72nd Symposium of Research Society of the Ship Performance in Actual Seas, Apr. 2016, English, Tokyo University of Marine Science and Technology, Domestic conference

  Oral presentation


• Numerical Evaluation of Speed Loss in Actual Sea in Each Simulation Method 2 (Time Series Analysis)

  SASA KENJI, FALTINSEN,ODD M, PRPIC-ORSIC, J

  日本船舶海洋工学会第 2回推進・運動性能研究会, Oct. 2015, Japanese, 九州大学応用力学研究所, 実海域における荒天時の船速低下について、前報から引き続いて不規則波中の時系列解析として評価可能なモデルとした。, Domestic conference

  Oral presentation


• Quantified Evaluation and Validation of Speed Loss at Actual Seas in Each Simulation Method

  SASA KENJI, FALTINSEN ODD M, SHIOTANI SHIGEAKI, UCHIDA MAKOTO

  日本船舶海洋工学会第 1回推進・運動性能研究会, Jun. 2015, Japanese, 大阪府立大学 I-siteなんば, Domestic conference

  Oral presentation


• A Consideration of Ship Performance in Weather Routing -Numerical Modeling of Speed Loss in Seaways-

  SASA KENJI

  Joint Symposium of Brain-Circulation and Maritime & Urban Engineering Programs, Mar. 2015, English, 大阪大学 吹田キャンパス 理工学図書館３F, International conference

  Nominated symposium


• Problems and Improvement of Actual Sea Measuring for Ships in International Voyages

  SASA KENJI, SHIOTANI SHIGEAKI, TERADA DAISUKE

  日本船舶海洋工学会 実海域性能研究会, Sep. 2013, Japanese, グランフロント大阪ナレッジキャピタル タワーC 8階会議室RoomC05, Domestic conference

  Oral presentation


• A Study on International Maritime Transportation from Three Principles of Transportation (Part 1) --Ship Performance of Bulk Carrier in Rough Seas--

  SASA KENJI, TERADA DASUKE, SHIOTANI SHIGEAKI, WAKABAYASHI NOBUKAZU

  日本船舶海洋工学会 第21回推進性能・運動性能合同研究会, Jan. 2013, Japanese, National Maritime Research Institute, Domestic conference

  Oral presentation


• Safe Operation of Large Ferries navigates the Pacific Ocean from Viewpoint of Weather Routing and Forecast

  SASA KENJI, TERADA DAISUKE, SHIOTANi SHIGEAKI, WAKABAYASHI NOBUKAZU, TERUO OHSAWA

  日本船舶海洋工学会 実海域性能研究会, Jan. 2013, Japanese, National Maritime Research Institute, Domestic conference

  Oral presentation

• International Society of Offshore and Polar Engineering


• Japan Logistics Society


• Japan Society of Civil Engineering


• Japan Institute of Navigation


• ISOPE


• 日本物流学会


• Japan Institute of Navigation


• Japan Society of Civil Engineers


• Japan Society of Naval Architect and Ocean Engineers

• 超音波式精密水位計の観測精度向上に関する研究

  2003 - 2005

• 外洋における大型コンテナ船の貨物荷崩れのメカニズム解明と海難防止

  笹 健児, 寺田 大介, 牧 敦生, 山本 茂広, 高見 朋希

  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, Apr. 2025 - Mar. 2029


• 能動学習を用いた波浪中船体横揺れ運動の極値推定法の開拓

  高見 朋希, 笹 健児, 北原 優, 宝谷 英貴, 牧 敦生

  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, Apr. 2025 - Mar. 2028


• 津波の来襲に備えた港湾内の巨大船および専用桟橋における新しい安全管理システム

  木村 安宏, 笹 健児, 榊原 繁樹

  日本学術振興会, 科学研究費助成事業, 基盤研究(C), 大島商船高等専門学校, Apr. 2024 - Mar. 2027


• 外気変動による海上輸送中の多段積みコンテナ内部の三次元熱流動と高精度な汗濡れ予測

  川原 秀夫, 笹 健児, 大澤 輝夫

  日本学術振興会, 科学研究費助成事業, 基盤研究(C), 防衛大学校(総合教育学群、人文社会科学群、応用科学群、電気情報学群及びシステム工学群), Apr. 2022 - Mar. 2025


• 二国間交流による海のビッグデータを活用したGHG排出削減および最適運航の高度化

  笹 健児

  日本学術振興会, 二国間交流事業, 二国間交流事業, 神戸大学, Apr. 2021 - Mar. 2024, Principal investigator


• OPE Optimal Routing System to Enable Risk Management of Rough Sea Voyage and Mooring Problem Due to the Uncertainty of Weather

  笹 健児, 陳 辰, 牧 敦生, 青木 伸一, 大澤 輝夫

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid, Grant-in-Aid for Scientific Research (B), Kobe University, Apr. 2020 - Mar. 2024


• グローバルデータベース構築によるアジア～豪州～欧州間の海上輸送の高精度化

  笹 健児

  学術研究助成基金助成金／国際共同研究加速基金(国際共同研究強化(B)), Oct. 2018 - Mar. 2023, Principal investigator

  Competitive research funding


• 新型浮消波堤の性能検証実験

  笹 健児;西尾 茂;竹内 海智;新里 英幸

  日立造船株式会社, 民間との共同研究, 民間との共同研究, 神戸大学, May 2021 - Mar. 2022, Principal investigator


• 安全運航・燃費削減のための効率運航操船支援システムの研究

  笹 健児, 小竿 誠, 浅木 耕介, 織田 博行, 田中 良和, 寺田 大介

  株式会社宇津木計器, 民間との共同研究, 民間との共同研究, 神戸大学, Apr. 2021 - Mar. 2022, Principal investigator


• Effects of hull inclination and human error in actual sea area on thermal damage of frozen and refrigerated container cargo

  川原 秀夫, 笹 健児

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), National Institute of Technology(KOSEN), Oshima College, Apr. 2019 - Mar. 2022

  本研究では、船の揺れや傾斜及び人為的ミスにて発生する冷凍・冷蔵コンテナでのドレン排出不良、空気の流入・流出による貨物損傷に注目し、1洋上を航行 するコンテナ船に積載される冷凍・冷蔵コンテナの熱環境変化に伴う貨物損傷の実態調査、2コンテナ周囲の環境変化とドレン排水口の開閉状態がコンテナ内の 温湿度変化に与える影響の把握、3気象条件を組み入れたコンテナ内の三次元的な熱流動の推定、4輸送中におけるコンテナからのドレン排水量、空気の流入・ 流出量と貨物の損傷予測を明らかにし、貨物損傷のメカニズムの解明及び品質管理の向上を達成する。 1年目は上記に示した「1洋上を航行するコンテナ船に積載される冷凍・冷蔵コンテナの熱環境変化に伴う貨物損傷の実態調査」を実施した。実際の輸送現場 (神戸、台湾(高雄))にて関係者を対象とした現地調査を実施し、冷凍・冷蔵コンテナの管理において現場での詳細な問題点および望まれる対策を明らかにし た。


• 安全運航・燃費削減のための効率運航操船支援システムの研究

  笹 健児, 小竿 誠, 宇津木 洋三

  株式会社宇津木計器, 民間との共同研究, 神戸大学, Apr. 2020 - Mar. 2021, Principal investigator


• 貨物の汗濡れ確率を導入した次世代の海上コンテナ輸送における最適運航モデル

  笹 健児

  学術研究助成基金助成金／挑戦的研究（萌芽）, Jun. 2018 - Mar. 2021, Principal investigator

  Competitive research funding


• 荒天時における船舶の安全性・効率性に関する評価法の研究

  笹 健児、田中 良和、織田 博行

  商船三井テクノトレード株式会社, 民間との共同研究, 神戸大学, Apr. 2019 - Mar. 2020, Principal investigator


• 地球規模に拡大する液体輸送のスロッシング影響を加味した船舶の最適運航システム

  笹 健児

  科学研究費補助金／基盤研究(B), Apr. 2016 - Mar. 2019, Principal investigator

  Competitive research funding


• 荒天時における船舶機関の運転制御および波浪影響の連携評価による新運航システム

  笹 健児

  学術研究助成基金助成金／挑戦的萌芽研究, Apr. 2015 - Mar. 2018, Principal investigator

  Competitive research funding


• Establishment of a Prediction System for Seakeeping Performance of Ships in Actual Seas with Enhanced Rankine Panel Method and Its Practical Applications

  KASHIWAGI MASASHI, HU CHANGHONG, HE GUANGHUA, SASA KENJI, KUGA SHINTARO, YASUDA EIJI, ASHIDA YUICHI, SEKI YUTA, YOSHIDA JUNKI, OHTAKI MARI, TANIGUCHI TAKUYA, HARA TAKESHI

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (A), Osaka University, Apr. 2013 - Mar. 2017

  In order to establish a Rankine panel method in the frequency domain as the core calculation method in the prediction system for seakeeping performance (including the fluid-structure coupled responses) of ships in actual seas, an intensive study was made for making the method applicable to a wide range of oscillation frequencies and forward speeds of a ship. Experiments have been also conducted to see the importance of nonlinearity in hydrodynamic forces acting on a ship and it was found that the nonlinearity in the cross-coupling hydrodynamic forces between heave and pitch plays an important role in the nonlinearity in ship-motion amplitudes around the resonant frequency. Furthermore, simultaneous measurements have been successfully made for obtaining the spatial unsteady-pressure distribution on the ship hull by use of 224 FBG-type pressure sensors, together with the measurement of wave-induced ship motions, added resistance, and unsteady wave pattern on the free surface.


• 瀬戸内海の海難ゼロを目指す海のITSを利用した航海システムの構築

  塩谷 茂明

  科学研究費補助金／基盤研究(B), Apr. 2013 - Mar. 2016

  Competitive research funding


• 国際海上輸送における安全性・経済性・海洋環境を統合した新しい最適運航システム

  笹 健児

  科学研究費補助金／基盤研究(B), Apr. 2013 - Mar. 2016, Principal investigator

  Competitive research funding


• 海象情報統合システムの統計フィルタによる低気圧浪浪の新予報技術の開発

  笹 健児

  科学研究費補助金／萌芽研究, Apr. 2012 - Mar. 2015, Principal investigator

  Competitive research funding


• Basic Study of Tidal Stream Electricity Generation for Obatake Strait

  SHIMIZU Seiji

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Oshima National College of Maritime Technology, 2011 - 2013

  Tidal stream distribution in Obatake strait was observed for electricity generation. There are 3-dimensional flows near a bridge's piers due to complicated geography of the strait and the existing piers. Depth-ward reducing of the stream isn't so much. So, the strait has 5 times higher energy than expected and a turbine can be set deep without a loss. Various Darrieus water turbines' properties were investigated. To improve their difficulty of starting revolution, assist experiment was carried out. It resulted in helping well starting revolution to harness low stream power efficiently. Expecting electricity was estimated from these results. Only flow speed of the tide in Obatake which explains the observed tide could be calculated by CFD.


• 振動応答から見た悪天航海中の船舶貨物の損傷防止を実現する最適積載システム

  笹 健児

  科学研究費補助金／基盤研究(B), 2010 - 2012, Principal investigator

  Competitive research funding


• Prevention of Marine Disaster by Numerical NavigationSystem using Marine ITS

  SHIOTANI Shigeaki, KOBAYASHI Eiichi, WAKABAYASHI Nobukazu, OHSAWA Teruo, MAKINO Hidenari, SHIMADA Youichi, SASA Kenji, TERADA Daisuke

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Kobe University, 2010 - 2012, Coinvestigator

  Existing transport, emphasized only the safety of vessels, lading, and crews used in large-scale transport from an economic perspective. As results, numerous marine accidents including collisions and sinking had been generated, and there are concerns that the increase in global vessel ownership will result in a high frequency of marine accidents for crowd of many ships. In light of these circumstances, comprehensive research that integrates safety, economic efficiency, and environmental preservation, of the three principles of transport, and improves the tangible and intangible aspects of transport technology is urgently needed. In this research project, we construct the marine intelligent transport system applied ITS of a road traffic for zero of marine accidents. This system was created by numerical navigation of marine transportation.

  Competitive research funding


• A Study on Ship Operation and Prevention of Casualty due to Abnormal Tide and Heavy Fog in the Seto Inland Sea

  MIZUI Shinzi, SASA Kenzi, HIBINO Tadashi, NAGAI Norihiko, SHIMIZU Katsuyoshi

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Hiroshima National College of Maritime Technology, 2006 - 2008, Principal investigator

  港湾計画においては構造強度や海洋環境など様々な観点から多面的に検討されるが,その中でも最も重要な指標の一つに港内静穏度,特に波浪や風による影響の検討がなされる.瀬戸内海など外洋に面していない海域の港湾の場合,波浪条件が静穏であることから外洋性港湾ほど詳細な安全性の検討がなされているとは言い難い.しかし,著者らは瀬戸内海における港湾において,強潮流時にも船舶が運用困難となる事例から潮流による運用困難な影響も詳細に検討する必要性を示した.当初は潮流による船体運動への影響評価として,静止した船舶が潮流を受けた場合に移動する距離を潮流条件ごとに比較検討した.しかし,実際には船体が桟橋に着桟する局面では舵とプロペラの力を用いて姿勢制御を行う操船方法であり,これらの影響を考慮した船体運動の数値解析法は検討できていない.潮流が卓越する中で運用せざるを得ない港湾の運用限界を定量的に評価するため,舵とプロペラによる操船制御の動作を考慮した船体運動の解析手法へ改良する必要があると考えられる.瀬戸内海の船舶運航者を対象に潮流下での運用の困難度をアンケート調査で把握し,港湾運用の現状を改めて整理した.これをもとに前報で対象とした潮流影響が顕著な離島航路のフェリー港湾まわりの潮流・水質調査を大潮日に数回実施した.さらに潮流中における着桟操船時の船体運動について,舵力,プロペラ推力,ポンツーン衝突時のエネルギー吸収などの影響を再現できる数値計算法の開発を実施し,再現精度を検証するとともに強潮流下における港湾での新たな運用限界の検討方法を提案した.この結果,実際の着桟局面での船体運動を定量的に評価することが可能となり,強潮流が卓越する港湾での運用の困難度を評価する一手法を確立することができた.


• 荒天時における港外海域の船舶座礁に関する安全性評価システムの開発

  笹 健児

  日本学術振興会, 科学研究費助成事業, 若手研究(B), 広島商船高等専門学校, 2004 - 2005, Principal investigator

  港外波浪が厳しい条件の場合、うねり・長周期波の影響で船舶の入出港や港内の荷役・係留が非常に困難となる。台風や低気圧の接近で上記作業が困難な場合、現行の運用基準では船舶は港外海域へ避泊するように定めている。港湾計画では操縦運動論により風のみによる錨泊船の船体運動を計算した結果から運用基準が検討され、解析手法も水平方向の運動のみが対象で周波数に依存した流体力で運動解析するため、長周期運動の再現精度に問題がある。うねり、長周期波、変動漂流力の波浪影響を正確に検討した事例も存在せず、現状での港外避泊の安全性の検討は極めて不十分である。近年、港外避泊した船舶が走錨・座礁する海難事故が多数発生し、人命、船舶、貨物の損傷・損失や油流出の環境汚染が改めて深刻な問題となっていることから、港外避泊の現状に関する海難事故時の波浪データの分析、避泊時の船体運動に関する新たな数値モデルの改良を行った。計算結果より風と波浪の影響について定量的に比較検討し、安全性の評価方法を考察するものである。 本年度の実施内容としては、 (1)船舶運航者を対象に港外避泊の現状に関するアンケート調査を実施し、錨泊が困難となる状況、錨泊中における船体運動の特徴を取りまとめた。 (2)2002年7月に発生したS港での6万トン級穀物船の座礁事故時における港外の観測波形をデータ解析し、座礁までの変化傾向を調査した。 (3)錨泊時の船体運動に関しては、三次元グリーン関数法による流体力・波浪強制力、摂動展開法による変動漂流力の周波数解析とインパルス応答を考慮した運動方程式の時系列解析を用いた。錨・錨鎖の係留力はカテナリー理論に基づき、錨の限界把駐力を数回超えた後に走錨すると考えた。 17年度は16年度の研究結果をもとに、いくつかの海難事例を詳細にデータ調査し、座礁海難時の外力条件を比較・分析するとともに数値シミュレーションモデルの他ケースへの精度検証を行なった。


• Development of Evaluation System of Ship Motions at Entering and Departure Harbors Facing the Open Seas.

  KUBO Masayoshi, SASA Kenji, MIZUI Shinji, YONEYAMA Haruo, NAGAI Toshihiko, SHIRAISHI Satoru

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), 2002 - 2004, Coinvestigator

  It is very important to maintain the safety when ships enter into or depart from harbors. At first, ship motions are successfully observed in swells in this study. It is shown that the difficulty is occurred during the berthing operation inside harbor as well as the harbor entrance. Observed data are analyzed to know these difficulties numerically. Numerical simulations of ship motions in swells during the entering and departing are newly constructed at first. The accuracy seems to be enough to reproduce against some cases of observed ship motions. Moreover, it is necessary to define the new evaluation parameters about the difficulty of the berthing operation. It is proposed and verified as the "Difficulty of Berthing Function." The function can evaluate the operational difficulty quantitatively, this point should be considered in the harbor tranquility.

  Competitive research funding


• 瀬戸内海における濃霧時の船舶運航および濃霧を支配する気象海象について

  海洋観測研究開発, 2004

  Competitive research funding


• 瀬戸内海における潮位観測システムの構築および潮位変化による船舶の運航障害

  沿岸環境・利用の研究開発, 2004

  Competitive research funding


• 荒天時における港外避泊船の海難防止に関する研究

  運輸分野における基礎的研究推進制度, 2003

  Competitive research funding


• 海上輸送中における貨物損傷の防止対策について

  その他の研究制度, 2002

  Competitive research funding


• Cargo Damage in Ships During Maritime Transportation

  The Other Research Programs, 2002

  Competitive research funding


• Study on the Evaluation of Safety of Ship Motions at Entering and Departing Horbours Facing Open Seas

  Grant-in-Aid for Scientific Research, 2002

  Competitive research funding


• 台風時における港内係留船の係留限界予測に関する研究

  その他の研究制度, 1999

  Competitive research funding


• A Study on the Prediction of Mooring Criteria in Harbour Facing Open Seas

  Cooperative Research, 1999

  Competitive research funding


• 波浪の数値予測について

  Competitive research funding


• 船体運動（波浪中）について

  Competitive research funding


• 荒天時の新たな港外避泊法に関する研究

  Competitive research funding


• 異常潮位，潮位変化による船舶の運航障害に関する対策検討

  Competitive research funding


• Transportation System of Water Using Vessels

  Competitive research funding


• Numerical Predictions of Wave Growth

  Competitive research funding


• Ship Motions in Waves at Various Situations

  Competitive research funding

• 波浪計測装置

  笹健児, 田中良和, 織田博行, 黄鎮川, 宇津木洋三, 小竿誠

  特願7508091, 21 Jun. 2024, 商船三井テクノトレード株式会社, 特開7508091, 21 Jun. 2024, 特許7508091, 21 Jun. 2024

  Patent right


• 航行支援装置

  笹健児, 田中良和,織田博行, 黄鎮川, 宇津木洋三, 小竿誠

  特願7483535, 07 May 2024, Mitsui O.S.K. Lines, Ltd., 特開7483535, 07 May 2024, 特許7483535, 07 May 2024

  Patent right


• 港湾における船舶運航限界の予測システム及び予測方法

  特開2003-203300, P6389

  Patent right