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Article type: Cover
2011 Volume 125 Pages
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Article type: Appendix
2011 Volume 125 Pages
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Article type: Appendix
2011 Volume 125 Pages
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Article type: Index
2011 Volume 125 Pages
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Article type: Index
2011 Volume 125 Pages
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Kenjiro HIKIDA, Kenji YOSHIMURA, Junji FUKUTO, Masayoshi NUMANO
Article type: Article
2011 Volume 125 Pages
1-8
Published: September 25, 2011
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A navigation support system named Visual Lookout Support System (VLSS) has been under development. The VLSS uses a Head-up display (HUD) and it supports watch operation especially for collision avoidance. Information on target ships is displayed on the HUD enabling to see both target ship silhouette and its information simultaneously. This function will help officers of the watch to recognize the target information of observing ship without disturbing their watch. A series of simulator and field experiments were performed for evaluation of workload of the watch with the VLSS and for subjective evaluation of VLSS functions under several navigation conditions. From the results, the VLSS has been proven to be effective to reduce the workload and to help the watch task effectively.
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Atsushi SUZUKI, Tadasuke FURUYA, Takafumi SAITO, Ruri SHOJI
Article type: Article
2011 Volume 125 Pages
9-15
Published: September 25, 2011
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This report shows a method for visualization of combined observation images from a ship and routing information of the ship. It enables us to browse the scene on problem area efficiently. We use hierarchical image gathering technique to gather moving objects and changes. The technique generates still images by gathering the moving parts from image sequences by fixed camera, and displays them hierarchically, so that a user can easily browse the scene by looking at the images displayed hierarchically. In order to apply the technique for images from ship, We extract sea-sky-lines and unify them of image sequences. And, we plot routing line of a ship and gathered images on map.
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Bilan ZHU, Tadasuke FURUYA, Masaki NAKAGAWA, Ruri SHOJI
Article type: Article
2011 Volume 125 Pages
17-23
Published: September 25, 2011
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This paper describes a study on ship name reading for small ships. It is very important to understand and to inspect the movements of other ships and the surrounding situations by using the AIS information, radar or watching and so on. Although AIS can provide useful informations for ships, small ships do not have the obligation to install AIS. However, identification of small ships is very important for safe sailings and traffic analyses on sea. Therefore, we aim at a constructing a system that reads ship names to identify them. To read ship names efficiently, it is extremely important to prepare a database of the ship names. Therefore, at the first step we construct a system that builds a database of the ship names by reading the text fields written on small ships and storing them. Then, based on the information we will elaborate a character string recognition system that specializes in the ship name recognition.
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Tadasuke FURUYA, Atsushi SUZUKI, Takafumi SAITO, Yudai NAGASHIMA
Article type: Article
2011 Volume 125 Pages
25-31
Published: September 25, 2011
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In this study, we propose a technique for providing stabilized images without roll and for inferring the direction of roll from photographic images, based on the technique for abstracting and creating a consistent horizon line. The chief causes for maritime accidents with boats are "Disregard for weather and marine conditions," "Not keeping sufficient lookout," "Geographical ignorance," and "Insufficient information about waterways." Given this state of affairs, we believe it is important to construct a system that will give ship and boat handlers useful information and aid them in their handling. The focus of the present study is on the "roll" of ships and vessels. In it, we first abstract the horizon line from photographic images. Next, we measure the "roll" in each frame based on positional coordinates of the horizon line in those photographic images. Using the calculated "roll," we then infer the "roll" that follows. While we cannot say based on experimental results that the figures are accurate when it comes to roll volume (the amount of lift), we can make a rough estimate on the timing of rolling. This information is then provided to ship handlers for use in handling.
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Kazuhiko HASEGAWA, Junji FUKUTO, Tadanori TAKIMOTO, Masahiro YAMAZAKI
Article type: Article
2011 Volume 125 Pages
33-41
Published: September 25, 2011
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"Marine Traffic Simulation System" has been developed by the first author and others for long years. It has three simulation modes. First mode is normal navigation mode. It reproduces realistic traffic flows according to the predefined planed route. Second mode is collision avoidance mode. It has the feature of automatic collision avoidance for all ships besides the normal navigation mode. Third mode is external data mode. It reproduces traffic flow according to the data given by such as AIS. With collision avoidance mode, more realistic traffic flow can be reproduced. However, the validation of the simulation result is not yet done, because it was difficult to get the real traffic flow data before AIS data acquisition system established. This is one of the main purposes of this paper. The system is applied for southward area from Tokyo Bay. Assuming external mode as a real traffic flow, other two modes are evaluated. Normal navigation mode overestimates the navigational risk, while collision avoidance mode reproduces it fairly well in terms of several indices to represent the risk of the area. Three indices; number of occurrence of CR≧0.9, near-miss, and collision respectively, are proposed to assess the navigational risk and discussed. The normalization of these indices, traffic density and gaming area is also proposed and verified including the simulation results of two other areas.
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Yoshihiro HIRAO, Fujio KANEKO
Article type: Article
2011 Volume 125 Pages
43-48
Published: September 25, 2011
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The marine transport of nuclear fuels in Japan's coastal waters has been safely conducted using an exclusive vessel meeting national safety standards. One of the current issues is to prepare the changes in the situation proactively since it is expected that the progress of the nuclear fuel cycle will bring an increase in volume and diversity of packages to be transported. The organizations concerned have begun to survey recent studies to know the possibility of risk management for the marine transport system. Of accidents related to marine transport, collisions between vessels are regarded as one of the risks that can reasonably manage by the reliable infomation. Here we focus attention to onboard Automatic Identification System (AIS) data to examine traffic characteristics and the applicability to the risk asessment. In this study, area traffic information is arranged according to aspects of interest by analyzing AIS data received several months at the port of Mutsu-Ogawara, place of loading packages, and the collision frequency results thereby estimated are reported. Finally, the uses of the obtained information for our purpose and their effects are considered.
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Kenji YOSHIMURA, Yasuyuki NIWA, Kenjiro HIKIDA, Junji FUKUTO
Article type: Article
2011 Volume 125 Pages
49-54
Published: September 25, 2011
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"Inadequate Look Out" is major cause of maritime accidents, and 20% of "Inadequate Look Out" is caused by low level of arousal. Low level of arousal is cause of reduce of perceptual function. To prevent maritime accident, it is effective actions to maintain watch keeper at a proper arousal level. This study was focused on bodily movement in bridge to evaluate arousal level. For this purpose, we conduct experiments using ship handling simulator. 14 subjects participate in the experiment who navigates a ship 4 hours alone. This paper proposes that the effect of arousal level and bodily movement.
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Chihiro NISHIZAKI, Hiroko ITOH, Kenji YOSHIMURA, Nobuo MITOMO
Article type: Article
2011 Volume 125 Pages
55-61
Published: September 25, 2011
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There are many marine accidents by human factors. Experiments with bridge simulator are effective for analysis of human factors. Analytical approaches with bridge simulator have already been conducted. But analytical method with bridge simulator hasn't been established yet. The purpose of marine accident analysis is identification the cause of marine accidents and consideration of accident countermeasures. In previous report, we detected an error that could have been occurred in a collision accident through the expression with simple task model like event tree. But in order to identify the cause of the accident, it is necessary to confirm the process of detected error. In this study, we propose a method to identify the process of judgment error on collision risk by modeling judgment patterns. In the result of modeling judgment patterns, it was made clear that the cause of the collision accident was the judgment errors of the targets' navigational position.
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Junji FUKUTO, Kazuhiko HASEGAWA, Fumihiko SAKAI
Article type: Article
2011 Volume 125 Pages
63-71
Published: September 25, 2011
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Based on the rapid advance in ICT, developments and introductions of new services using new technology such as AIS Application Specific Messages are underway. These services will be useful for mutual relationship between encountered ships such as a collision avoidance support system. Recently, cost benefit analysis is required to introduce such a newly developed system. When evaluating cost benefit, the utility of the system is necessary. However, it is difficult to get the utility quantitatively because there is no experience of the new system enough for measuring its utility. Then we use subjective utility which comes from expert judgment. When we get the expert judgments, suitable experiences of the new system are necessary. Simulator run is one of the best ways to get the experience. To express mutual actions between encountered ships in a simulator, a control system for traffic ships is needed. The system includes not only a function for expressing traffic ship's motion, but also functions for expressing the effect of intelligent systems. In this paper, we introduce an automatic collision avoidance system and a framework for implementing the intelligent systems to a ship handling simulator by using inter-process communication and then discussed the results of simulation runs of three-ship-collision-scenario.
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Yohei Matsumoto
Article type: Article
2011 Volume 125 Pages
73-82
Published: September 25, 2011
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For the purpose of developing the computer based automated navigational watch system, this paper tried one of the basic techniques of computer vision, color based pixel classifier, to determine whether a pixel is sea surface or not. The technique is based on Bayes rule and use RGB color histogram calculated by labeled photos. Using 128 photos for learning, our experiment showed that the Bayes classifier detects sea pixels with 80% true positive and 25% false positive. The result is sufficient to use the classifier as the one constituting the vision algorithm of our watch system.
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Masanori WATAGAWA, Katsutoshi KOZAI, Masao FURUSHO, Hiroyuki SHIMADA
Article type: Article
2011 Volume 125 Pages
83-89
Published: September 25, 2011
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Advanced Land Observing Satellite (ALOS) has been launched to make observation of global land coverage and so on. Nowadays, the number of AIS-equipped ships is increasing for maritime traffics. This study proposes a methodology of monitoring in coastal. environments by Matching AIS data to ALOS images. We collected ALOS images and AIS data in OSAKA Bay from 2006 to 2011. We evaluated the most suitable methodology to extract ship data from ALOS and AIS data. The results show that our methodology can recognize and classify various ships for navigation in OSAKA Bay. Our research suggests that our methodology might be effective for monitoring in coastal environments by using ALOS images with simultaneous acquisition of AIS data.
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Ayumi ISHIKURA, Shogo SUGIHARA, Yuji HAYASHI, Koji MURAI
Article type: Article
2011 Volume 125 Pages
91-97
Published: September 25, 2011
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When vessel's commanders receive assistance from tugboats on entering and leaving a berth, they use the agreed communication phrases, body language, hand gestures, and so on in each pilot district. In Japan, the agreed communication phrases named "The Settled Term of Maneuvering Orders for Towage Work" are defined by the Japan Harbor Tug Owners' Association. However, the results of the current state survey, which was executed by authors' group in 2010, showed that various kinds of "Non-standard" tug orders were actually used. The findings from the results also suggested that, when vessel's commanders used "Non-standard orders" including in the above-mentioned "The Settled Term," there were some gaps in perception between the vessel's commanders and the tugboat's commanders. These results reasonably lead to the conclusions that some definitely-agreed Maneuvering Orders are essential.
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Masaya YUKIHIRA, Hisaaki TAKAYAMA, Kenichi SHIMIZU, Masaji GODA
Article type: Article
2011 Volume 125 Pages
99-104
Published: September 25, 2011
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This study clarifies the superiority of on-board training as liberal arts subject. The authors conducted questionnaire surveys to 78 students who participated the on-board training implemented by the Nagasaki University during three years from 2008 to 2010. The survey was based on the free description questionnaire method where the participating students answered the questions before and after the on-board training. The answers were analyzed by using KH Coder software. As a result of analysis, it was suggested that the students learned the importance of mutual assistance, collaboration and cooperation with their colleagues through putting themselves in an unfamiliar environment such as shake, seasickness, and tight space. It was also suggested that the students could cultivate the group activity by keeping regular hours. Particularly from the result of the survey after the on-board training, it appears that the unfamiliar environment of on-board training provides an educational superiority to other trainings on land.
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Kenichiro NAGAIWA, Toshihiko MATSUO
Article type: Article
2011 Volume 125 Pages
105-112
Published: September 25, 2011
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Modal shift from truck to railway or ship is very important policy to achieve the Kyoto protocol's targets in Japan. In particular, ferry and Roll-on/Roll-off ship have been paid attention as a mean of realizing intermodalism. Therefore, a lot of researchers have shown the thesis about modal shift, though they have analyzed the mode choice factor of ferry, container ship and rail way in the restricted zone. However, they have not analyzed the factor of ferry and Roll-on/Roll-off ship. In this paper, the authors studied on the route choice model of the truck for modal shift. Firstly, the authors will show a route choice mode with multi-nominal logit model. Secondly, we will investigate the factor of route choice. Finally, we will describe the effective policy for the modal shift and the reverse modal shift from the viewpoint of policy.
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Takeshi SHINODA, Shogo KITAJIMA
Article type: Article
2011 Volume 125 Pages
113-121
Published: September 25, 2011
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Container terminal is a important base point for physical distribution to connect between land and sea transportation. The highest priority on container transportation is given to time value to satisfy the requirement of customers under the present situation. Providing higher performance at container handling to container ship is the top priority at container terminal. But, this priority occasionally causes some problems such as to deploy excessive facility for container handling cargo gear, to suspend container handling to chassis from outside, which might influence the management for container handling. The purpose of this paper is to evaluate improvements by functional design based on analysis of container handling operation. The process data of container handling operation for cargo gears are obtained to develop the datalog system for gantry crane operation, to construct the container handling data base for transfer crane operation and to study a process data by work sampling for chassis operation. Petri-network model of container handling is constructed to based on the process data. An important consideration for adequate numbers of container handling gears is carried out to apply the developed methodology, as a trial calculation.
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Yoh-ichi KAWAGOE, Susumu OTA, Hideyuki OKA
Article type: Article
2011 Volume 125 Pages
123-128
Published: September 25, 2011
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Due to concerns over CO_2 emissions, demand for seaborne trade of Compressed Natural Gas Vehicles and Hydrogen Fuel Cell Vehicles has been increasing and carriage by Pure Car Carriers (PCCs) is becoming essential. Thus, the Fire Protection Sub-Committee of the International Maritime Organization started the development of requirements for safe carriage of such vehicles and the authors are engaged in this task. One of the significant risks owned by carriage of such vehicles is accumulation of hydrogen and natural gas, which are lighter than air, under ceiling in case of leakage. Though the accumulation of gases depends on air flow, air flow in cargo spaces in PCCs has not been evaluated. The purpose of the research is to provide a basis for the research on the prevention of accumulation of gases by grasping actual air flow in such cargo spaces. We measured air flow on PCCs occupied by vehicles while berthing under some typical ventilation conditions during voyage, and almost calm positions were observed depending on ventilation condition.
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Masashi KAWAI, Hideki KADOMURA
Article type: Article
2011 Volume 125 Pages
129-135
Published: September 25, 2011
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Swells which invade Toyama Bay and cause wave disasters on the coast of Toyama Bay are called Yorimawari Waves and they are feared by the people in Toyama. The big wave disasters have been occured on the coast of Toyama Bay with a period of about 10 years. The need of more reliable wave prediction system are increasing under these circumstances. The basic matters on Yorimawari Waves and the wave prediction system were considered in this study based on the reserches on Yorimawari Waves which had been carried out in Toyama National College of Maritime Technology since 1967 and the consignment study from Japan Science and Technology Agency in 2010. They are as follows. (1) The discussion on the origin of name of Yorimawari Waves. (2) The discussion on generation mechanism of surf beat. (3) The discussion on the problems of current wave prediction system and proposal of wave prediction system based on wave observation. These results are reported in this paper.
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Masashi YOSHIDA, Hajime CHIBA, Harumasa HOJO
Article type: Article
2011 Volume 125 Pages
137-143
Published: September 25, 2011
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Seasonal and regional variances of the marine environment have been measured in Toyama Bay. The purposes of these measurements are to prevent marine pollution, provide forecasts for fisheries as well as disaster. However, various sensors, such as those for measuring salinity and temperature of salt water, are required to conduct environmental observation in the coastal areas. Furthermore, practical arbitrary real-time observation is difficult because of the limitation of power supply methods that cannot cover such a wide range of observations. Therefore, by designating the buoys as the nodes, we conducted fundamental experiments on the sensor network. Upon measuring the receiving sensitivity and rate in the actual environment, that is, in Toyama Bay, we confirmed that the data relay among the buoys functions properly and useful data are acquired for designing circuits for the system.
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Jun TANEMOTO, Teruo OHSAWA, Shigeaki SHIOTANI
Article type: Article
2011 Volume 125 Pages
145-152
Published: September 25, 2011
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This paper discusses the accuracy and characteristics of ocean wind forecasts from the Japan Meteorological Agency (JMA) Global Spectral Model (GSM) and the National Center for Environmental Prediction (NCEP) Global Forecasting System (GFS) for the Afro-Asian monsoon region. Focusing on the two high-wind areas off Somalia and around Taiwan, the accuracy of 24 to 168 hour forecasts is examined using the measurements from the scatterometer Sea Winds on the QuikSCAT satellite. The result shows that 1) NCEP-GFS provides slightly better forecasts than JMA-GSM in terms of a strong wind forecast, 2) both models have systematic tendencies of over- or under-estimation in the monsoon winds, and 3) they are partly due to the surface process over continents in the models.
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Hisaki NISHIYAMA, Ruri SHOJI, Kohei OHTSU, Brahim MEZAOUI
Article type: Article
2011 Volume 125 Pages
153-164
Published: September 25, 2011
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In recent years, ocean going vessels has become to use the weather routing (WR) under navigation. But in present situation, many ships still adopt "Ocean Passage Pilot" as a standard ocean passage route. However, that route is not always suitable for large and high-speed ship such as container ship. In previous studies, it was known that appropriate route selection is important to avoid the storm zone and reduce fuel consumption. In this study, we examine the passage time and fuel consumption in the standard routes comparing with the recent WR simulation results. Initially, we performed Minimum Time Route (MTR) and Minimum Fuel Route (MFR) simulation in North Pacific and North Atlantic Ocean using the assumed performance of the container ship. In the WR simulation we used the General Bathymetric Chart of the Oceans for judgment of the navigable area. At first, using the WR simulation results, we made 10 different routes in the North Pacific Ocean and 7 different routes in the North Atlantic Ocean. And then, we investigated the ratio of the route selected by the simulation. After that, we considered the correlation between the difference of the specified passage time in the MFR and the fuel consumption by using WR simulation results. Finally, we describe the way to visualize the simulation results.
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Yoichi SHIMADA, Shigeaki SHIOTANI, Keiko TAKAHASHI
Article type: Article
2011 Volume 125 Pages
165-173
Published: September 25, 2011
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In this paper, we examine the influence of ocean model horizontal resolution on weather routing which is the optimum navigation using weather and oceanic conditions. Higher resolution ocean model succeeds to simulating more realistic strong currents such as the Kuroshio and Kuroshio extension. Although the weather routing in this study does not significantly save the passage time of the minimum time route, higher resolution ocean model has the possibility of decreasing the passage time of the minimum time route. It has also the possibility of changing the structure of the minimum time route significantly. These suggest that detailed current structure has influence on the minimum time route.
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Mitsuhiro MASUDA, Kuniaki SHOJI, Kiyokazu MINAMI, Koichi MASUDA
Article type: Article
2011 Volume 125 Pages
175-182
Published: September 25, 2011
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The present paper describes the application of the MPS (Moving Particle Semi-implicit) method to a prediction of the chain of disaster on water-front facilities induced by floating vessels washed onto the apron by tsunami. The chain of disaster means breaking the mooring tether, grounding on a wharf, drift to continental areas and the collision with building. In this research, the 3D-MPS method is applied, and the solitary wave and the bore like wave are applied as an assumed tsunami. The grounding on a wharf of floating vessel in the tsunami is paid to attention, and it reports on the result of examining the breaking of mooring tether of floating vessel by tsunami. In addition, the building and the vehicle are arranged on a wharf, and the chain of disaster is simulated.
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Mitsuhiro NAKAMURA, Yasuo YOSHIMURA, Yusuke KOMORI
Article type: Article
2011 Volume 125 Pages
183-190
Published: September 25, 2011
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Japanese purse seiners often capsize and many crews lost their lives. Previous investigations or reports show that the cause of capsizing is surf-riding and broaching in following sea or wild operations or some mistakes of handling. In June 2008, however, the purse seiner capsized and sank when it was only drifting with sea anchor. As long as this accident, the other factors may concern the capsizing. In this paper, the authors focus this purse seiner's accident and have carried out the model experiments in waves considering actual operational situation and attempt to clarify the capsizing factors. In these experiments, opening area of free-port of vessel and existing of sea anchor as well as wave conditions are examined. As the result, it is found that the close of free-port is the major factor of capsizing. Also, the over hung stern of fishing vessel cause significant reduction of stability in following and head sea. Furthermore, sea anchor can be a factor of capsizing for such vessels. These can be factors of capsizing not only for Japanese purse seiners but also for almost every Japanese fishing vessel.
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Hidenari MAKINO, Nobukazu WAKABAYASHI, Yoshiji YANO, Shigeaki SHIOTANI
Article type: Article
2011 Volume 125 Pages
191-197
Published: September 25, 2011
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External forces of marine weather, such as waves, currents and wind flows, affect the course and speed of a ship under way. As a result, marine accidents, such as collisions or grounding, may occur, particularly in inshore areas. On coasts where earthquakes and tsunamis occur frequently, such as the Japanese coast, a tsunami that advances into a bay from the open sea is influenced by the submarine topography. It grows into a huge wave that could cause tremendous damage to ships under way and at anchorage. A massive earthquake occurred in the Tohoku and Kanto regions of Japan on 11 March 2011. In response, a tsunami alert, a tsunami warning and an advisory were issued for the entire Pacific coast region. This research investigates the evacuation behaviour of ships by AIS data in Tokyo bay and Osaka bay after the tsunami warning was issued. The unusual behaviour observed was attributed to the emergency evacuation of ships. In addition, the propagation direction of the tsunami was clarified by analysing the drift situation of each ship.
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Kenji SASA, Daisuke TERADA, Nobukazu WAKABAYASHI, Shigeaki SHIOTANI
Article type: Article
2011 Volume 125 Pages
199-207
Published: September 25, 2011
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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.
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Hironori YASUKAWA, Noritaka HIRATA, Susumu TANAKA, Satoshi ITO
Article type: Article
2011 Volume 125 Pages
209-219
Published: September 25, 2011
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Captive model tests were carried out to capture the hydrodynamic force characteristics on maneuvering for a twin propeller and twin rudder ferry with L/B=6.25, B/d=3.75 and C_b=0.53. Based on the test results, the hydrodynamic force derivatives and coefficients were determined according to the MMG model procedure including an equivalent single rudder model newly proposed. In the equivalent single rudder model, two rudders for port and starboard are treated as a single rudder arranged in centerline of the hull within restriction of the same rudder angle for port and starboard. The equivalent single rudder model can avoid complexity of the existing rudder force model for the twin rudder ship. The hydrodynamic force coefficients with respect to hull, propeller and rudder for the ferry are provided together with hull hydrodynamic force characteristics due to bow thruster operation. These data is useful for maneuvering simulation of a similar ferry.
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Yoshiji YANO, Masao FURUSHO, Yasuyuki TODA, Naoki YAMAMORI
Article type: Article
2011 Volume 125 Pages
221-226
Published: September 25, 2011
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The evaluation examination of self-polishing anti-fouling bottom paint has been carried out by training ship Fukae-maru (449G/T) of the graduate school of maritime sciences, Kobe University. For these past three years, 3 kinds of bottom paint of types low-friction coating, improved conventional paint and conventional paint have been evaluated by speed trials at Harima-Nada of the Seto Inland Sea. The frictional resistance of hull based on the viscosity of sea water accounts for 70-80% of all resistance at low speed range and accounts for 40-50% at high speed. The improvement of the frictional resistance of bottom shell plating reduces fuel consumption of a ship and leads to a reduction of the greenhouse gas emission at the same time. As a result of the speed trials, 3% or more of fuel-saving was effected with improved conventional paint and 9% or less of fuel-saving with low friction paint, compared to conventional anti-fouling bottom paint.
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Tadasuke FURUYA, Yuki ARIMURA, Koichi SHIMONO
Article type: Article
2011 Volume 125 Pages
227-232
Published: September 25, 2011
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We examined the effect of body roll on visual attention while viewing a motion picture. The picture was a scene along a water route that was videotaped from a deck of a ship whose vessel speed was about 13kt. Six observers viewed the pictures projected on a screen and were asked to detect a small target that was presented on the pictures for 1.5sec as soon as possible. The target was presented 13 times on average at a certain place in the picture and a certain period while the picture was viewed. Observer's body position was rolled by means of the motion base that was moved sinusoidally with an amplitude of 5 or 10 degree of arc and with a frequency was 0.07, 0.10, or 0.20Hz, while the observer viewing the picture. The results showed that 1) the reaction time to the target for the amplitude of 10 degree decreased as a function of the frequency whereas that for the amplitude of 5 degree was relatively constant irrespective of the amplitude, 2) the number of the trials where the observers failed to detect the target (or "response-error") was not different among conditions. These results suggest that body sway of an observer has an effect on visual attention when its amplitude is relatively large and the two indexes of visual attention (reaction time and response error) may not be mediated in the same process.
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Kimiyasu SAEKI, Shuji HISAMUNE, Yasuzumi FUJIMORI, Nobuo KIMURA
Article type: Article
2011 Volume 125 Pages
233-240
Published: September 25, 2011
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Hundreds of work accidents during handling and carrying fish in fishing ports were extracted from accident database collected by JF Zengyoren (A nationwide federation of fisheries cooperatives in Japan). Accident data belong to main six accident types were classified by type of fishery, sex and age. Number of accidents in each category was compared with census of fishery activities and categories in which accidents occur with high frequency are statistically extracted. Based on the result, it was indicated that detailed case study should be conducted for trawl, boat seine and set net fishery.
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Naoko FUKUDA, Ruri SHOJI, Kokoro KAMEYAMA, Kenji ASHIDA
Article type: Article
2011 Volume 125 Pages
241-247
Published: September 25, 2011
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Obviously seamen working on board can not seek medical attention at sea. Therefore, the primary prevention of diseases is needed for seamen, especially on board. This experiment was performed to monitor the health-related information of crew on board using VSAT (Very Small Aperture Terminal) satellite communications and internet. 5 crew of the training ship measured their blood pressure, pulse, body temperature, body weight, percent of body fat and step counts a day and inputted those data to the computer on board. The doctor interviewed them by TV conference system. The health management for seamen on board was indicated possible using the satellite communications and internet.
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Toshiro SUDO, Kohei HIRONO, Masaki FUCHI, Masao FURUSHO
Article type: Article
2011 Volume 125 Pages
249-256
Published: September 25, 2011
Released on J-STAGE: January 15, 2017
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Marine accidents caused by pleasure boats account for approximately 40% of all ship accidents in Japanese waters. Moreover, according to the results of "People's consciousness surveys concerning the sea, 2010", as carried out by the Japan Maritime Center in 2010, young groups, such as those in their teens, showed a tendency to keep away from the sea. Backed by these, in this study, we confirm the small boat's operators' license system and the change, and search the essence of marine leisure demanding basic act on ocean policy. Next, we investigate the number of successful applicant of the small boat's operators' examination, the number of the registered small boats, the number of domestic shipment of engines, the number of domestic shipment of small boats. Finally, the purpose of this study is to suggest and propose the increase measures of the small boat's operators for the popularization of the marine leisure and improvement of the small boat operators' license system.
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Article type: Appendix
2011 Volume 125 Pages
App3-
Published: September 25, 2011
Released on J-STAGE: January 15, 2017
JOURNAL
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Article type: Cover
2011 Volume 125 Pages
Cover2-
Published: September 25, 2011
Released on J-STAGE: January 15, 2017
JOURNAL
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