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Article type: Cover
1996 Volume 94 Pages
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Article type: Appendix
1996 Volume 94 Pages
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Article type: Index
1996 Volume 94 Pages
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Article type: Index
1996 Volume 94 Pages
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Article type: Index
1996 Volume 94 Pages
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Masayoshi KUBO, Shunsuke TAKAOKA
Article type: Article
1996 Volume 94 Pages
1-8
Published: March 25, 1996
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Recently energy saving and environmental conservation are becoming a world-wide problem. On the marine transport, it is gradually becoming important to utilize the natural and clean energy, for examples wind, wave and tide so on. Sail equipped vessel is one of the countermeasures answering the request. But, there are much to be desired for style of sailing-rig at reef. In order to remove this defect, we develop a new sailing-rig. This sailing-rig makes use of accordion curtains. If use this system, the wind effect at reef is smaller than that of a normal sailing-rig. By carrying out some experiments, we found some suitable points for practical application. Important results are summarized as follows : (1) New sailing rig reduce wind force effect at reef. (2) The ship's handling becomes easy as same as normal vessel. (3) Dragging anchor due to wind effect can be decreased (4) Initial and maintenance costs become cheap.
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Masayoshi KUBO, Shinji MIZUI, Kenji UEMURA
Article type: Article
1996 Volume 94 Pages
9-16
Published: March 25, 1996
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For designs of ship and marine structures, wind force is an important factor. Sea disasters sometimes happen under strong wind with rain falls, however, the wind force with rain fall has some ambiguous points. In order to decrease the sea disasters, it is very important to evaluate the wind forces with rain falls correctly. Measuring the wind velocity and wind forces simultaneously in the wind tunnel with rain falls, some interesting results are obtained. They are summarized as follows : (1) When we use the wind velocity by propeller-type wind gauge, the wind force seems to be underestimated. (2) The increment ratio of drag coefficient under rain fall attains 8% to 15% when the diameter of raindrop is 1.5mm and the rain fall is 3 to 7 mm/min. The increment ratio can not be neglected. (3) The increment ratio of drag coefficient can not be explained by the increment of air dencity with raindrops.
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Kiyoshi TACHI, Makoto ENDO
Article type: Article
1996 Volume 94 Pages
17-26
Published: March 25, 1996
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Some model tests were carried out to estimate the manoeuvrability of the new training ship Wakashio-maru IV, in which a controllable pitch propeller, bow and stern thrusters and a Schilling rudder were equipped. This paper mainly deals with experimental results of the wind tunnel test, the rudder open test and flow visualizations around the rudder. The results are as follows ; (1) Wind moment coefficients shows the difference between Wakashio-maru IV and III caused by their differences on sizes and types. (2) Wind forces of Wakashio-maru IV at 10m/s wind velocity is estimated as 2 times of III. (3) Normal force coefficients of the Schilling rudder shows better performances than the ordinary rudder at all rudder angles, which is from -70 deg. to +70 deg.. This increment of normal force coefficients is caused by end-plates effects. (4) The Schilling rudder decreases stall effects on normal force coefficients. This decrement is caused by effects based on the shape of rudder section. These results will be important information on ship handling for the navigators of the new ship.
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Akinori YUMURO, Hirosi UCHINO
Article type: Article
1996 Volume 94 Pages
27-33
Published: March 25, 1996
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This report deals with numerical simulation concerning an optimal control problem for parallel course change maneuver of a tanker-type ship having a rudder and a bow thruster as control input. The computation for the control input based on the linear optimal regulator theory is made by taking account of magnitude constraint on the control forces generated by means of state feedback. The optimization is made by minimizing the performance function made up of quadratic form including the term of terminal state. On the other hand, time-optimal control input is evaluated. And comparison is made between the former solution with saturated state and the latter solution represented by the bang-bang function. It is confirmed that the input determined from the optimal regulator theory is fairly similar to that due to the bang-bang control, when the weighting factor for the input force is sufficiently decreased.
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Kiyoshi AMAGAI, Kimihiko UENO, Akihiro YAMAGISHI, Nobuo KIMURA
Article type: Article
1996 Volume 94 Pages
35-42
Published: March 25, 1996
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Fishermen aboard small fishing boats often fall overboard without a life vest and then lost their life. The primary reason why fishermen cannot put on a life vest is that a life vest interrupt their fishing work. However fishermen must keep their life vest on in preparation for a man-overboard. Therefore the new life vest which is light and safety is developed. It's buoyancy is 6.5kgf and it became possible to do fishing work smoothly. For the advance of studing on this field, we need information about characteristics of the human body motion in waves with the new life vest to ascertain safety of it. This paper describes some parameters that have strong influence on the human body motion in waves and relations among those parameters. We studied the heaving of a man with new life vest which as buoyancy under regulations in the process of development. As a result the main points of this study are summarized as follows ; 1. Specific gravity of human body and only head are measured. 2. The relationship between a weight of the head (y) and a head measurement is given in the following equation ; y=30.4x-0.925 x : the third power of a head measurement 3. The damping coefficient and restoring coefficient of heaving of the human body with life vest are measured. 4. The heaving of a man with life vest in regular waves is simulated. 5. It become clear that a man with new life vest can float enoughly and it is naturally as well as possible to be breathed in waves.
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Michitoshi ISOZAKI, Syusaku IMO, Yuji TAMURA, Takayasu HORIYASU
Article type: Article
1996 Volume 94 Pages
43-50
Published: March 25, 1996
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Many navigation support systems are put to practical use. But when manoeuvering in port, captain oneself manoeuvers the ship. So it is important to know the physiological and mental intensity of captain in port for safty manoeuvering. The authors measured heart rate (HR) of a captain of T. S. Shioji maru manoeuvering in port for about one year. The HR was changed to relative one, represented as %HR. %HR is measured by the following equation : %HR=(HRex-HRrest)/(HRmax-HRrest)×100 given : HRex means HR during various activities. HRrest stands for the lowest HR while sleeping. HRmax indicates the predicted maximum HR due to age. The results are as follows. (1) %HR on each stand-by patterns are obtained. (2) Relation between %HR and experience in each port is partly obtained. (3) The factors that raised %HR are partly obtained. And some improvements are shown. (4) %HR shows the mental intensity of captain manoeuvering in port.
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Shigeo MITA, Kuniaki SHOJI, Shunichirou YAMATO, Kazuaki HASHIMOTO
Article type: Article
1996 Volume 94 Pages
51-57
Published: March 25, 1996
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Recently large bridges have been constructed in navigable waters congested by ships, so that ship collision with bridge piers is on the increase. To decrease the accidents various kinds of protective system are planned. The pelprene protective devices is developed for one of these protection systems. The shape of the cross section is honeycomb which is made from thermoplastic polyester elastomers named Pelprene. Usually honeycomb structure have been used for the bumper of the cars and have seldom been used for the offshore structure. In this paper the authors made a study of the wave forces acting on the protective devices by model experiments to decide how to install them around the bridge pier. The following results are obtained. The wave forces acting on the pelprene protective device model are smaller than that of the identically shaped box model. The horizontal forces : Fx have a maximum value at the region ; λ/L=3〜5. The vertical forces : Fz are smaller than horizontal forces in all the region of λ/L and have a flat distribution. In comparison with a model made from steel, Fx of the pelprene model is larger than that of steel model and Fz is smaller than that of steel model.
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Syunichirou YAMATO, Kuniaki SHOJI, Sigeo MITA, Kazuaki HASIMOTO
Article type: Article
1996 Volume 94 Pages
59-62
Published: March 25, 1996
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Owing to increase of marine traffic and bridge piers in navigable waters, ship collision accidents with bridges have been increasing. In these years, many bridges which span waterways are constructed. For example, the Honshu-Shikoku Connecting Bridges was opened and the Tokyo Bay Crossing Bridge-Tunnel is being constructed. After 1980, serious accidents do not happen but accidents do not decrease yet. The record indicates an average of ten collision accidents per year at least. To keep off these circumstances various kinds of protection system are planned. The protection system should be designed not only to protect the bridge structure but also to protect the vessel against serious damage. Pelprene protective device reported here is one of these protection systems contacted with bridge and absorbed colliding energy by elastic deformation of the protective device. Pelprene is a new material that is a kind of thermoplastic elastomer and has intermediate characteristics between rubber and plastic. In this paper authors studied the effect iveness of this protective system by model experiment. Dynamic penetration test of the ship model to the pelprene protective device was executed. Static penetration test was also executed in order to compare with dynamic test. From these experiments, the characteristics of this protective device and effectiveness for actual ship collision were considered.
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Kinzo INOUE, Hideo USUI, Shigeru IWAKIRI
Article type: Article
1996 Volume 94 Pages
63-71
Published: March 25, 1996
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Anchor is an important equipment for the mooring safety of a ship. According to the standard rule for anchor equipment, the weight of the anchor is determined based on the equipment number (EN) of the ship. Under this standard rule, heavier anchor is required to be equipped against a ship with large EN such as VLCC, in spite of its safety while the ship is moored at anchor. On the contrary, lighter anchor is required against a ship with smaller EN such as PCC, in spite of its dangerousness while anchoring. The present standard rule for anchor equipment based on the EN involves such contradiction from the view point of the mooring safety. In the present paper, an improved criteria for the anchor weight to be equipped is proposed to solve the contradiction on the rule. And where, the new index of (EN/displacement) is introduced. The value of this index is proportional to the risk index of the mooring safety.
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Masayoshi KUBO, Kazusei YAMAMOTO, Kenji ASAKI
Article type: Article
1996 Volume 94 Pages
73-79
Published: March 25, 1996
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There seems to be end of the number of breakage of mooring ropes on ship mooring. In ports facing to the open sea, they are occuring under severe weather conditions. In the past, strength of mooring ropes themselves was researched, however, the strength was not investigated under the condition where the ropes were moored on the ship. In this paper, the strength of mooring ropes was examined through a roller in order to estimate the fair leader effect. The obtained results are summarized as follows : (1) Breakage of mooring ropes occurs near a fair leader, even if the turn of the roller is smooth. (2) Through the fair leader, rope of one side pulling is easier to break than that of two sides pulling. (3) In the case of one side pulling, the rope tends to break at the part where the rope of pulling side contacts at first with the roller. In the case of two sides, the rope tends to break near the eye sprice.
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Kinzo INOUE, Shigeru USAMI
Article type: Article
1996 Volume 94 Pages
81-87
Published: March 25, 1996
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When a port reconstruction project is planned, it is necessary to investigate ships' safety and efficiency of operation which is affected by alternation of shore shape or sphere. And nowadays, marine traffic simulation is often used to evaluate a difficulty of ship operation within a planned area. Authors have been proposed the risk evaluation model of collision avoidance which can reflect an influence of geographical condition, sea condition and ship's manoeuvrability into the index value in the previous papers. And in this paper, as the application to a port reconstruction planning, we have evaluated the difficulties of ship's manoeuvring in a harbour area, carrying out the marine traffic simulation. As the result of above simulation, it is found that our evaluation model of collision avoidance can express properly the mental load of mariners, and useful when it is applied to port reconstruction planning.
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Kinzo INOUE, Maki HASEGAWA
Article type: Article
1996 Volume 94 Pages
89-96
Published: March 25, 1996
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When ships pass through the KURUSHIMA KAIKYO strait, they are forced to alter the channel in accordance with the direction of the tidal stream. Consequently, when it is time of turn of tidal stream, the encounters often occur with ships between going up ships in accordance with the present stream and coming down ships in accordance with the next stream. In the present paper, a result of the investigation into the actual condition regarding with the occurrence of such encounters is described. And authors propose a new safety policy to decrease such dangerous encounters on the basis of the statistical informations from the investigation results. The new policy is that the ships in accordance with the new tidal stream are demanded not to enter the channel for a given period of time after the time of turn of tidal stream and to wait at an appointed place. The availability of this safety measure was verified introducing the marine traffic simulation and it became clear that this new policy is very effective and practical.
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Masanobu TAHARA, Hiroshi TAKAGI, Masao KISHIMOTO
Article type: Article
1996 Volume 94 Pages
97-107
Published: March 25, 1996
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In the previous report, we designed the generating method of pseudo-views from radar signals, and confirm the availability of these pseudo-views. However, we only examined the possibility of that display method, and then there were several problems for the utilization. In this paper, we solved these problems, and turned this method to practical use. The summary results are as follows. (1) As the conditions surrounding the own ship is changing momentarily, the views must be displayed continuously to match the change of surroundings. By this continuous display we can distinguish between the fixed target and the moving target like a ship. (2) As the strengths of radar signals change by the sea conditions or the materials of the target, the adjustment for making the most proper picture must be able to operate. (3) We considered the effect of the variation of the color to generate the picture. Then, we were able to get the system that was practical use for operating ships, to display the pseudo-views from radar signals.
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Akiko MATSUBARA, Kouji MURAI, Nobuyoshi KOUGUCHI, Yuichi MIYOSHI
Article type: Article
1996 Volume 94 Pages
109-116
Published: March 25, 1996
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People get various data from the environment through five senses. So does a navigator when he navigates. Visual data are most important and indispensable among them. However it is authors' acknowledgement that a role of the visual information in the navigator's decision making process have not really recognized yet and consequently not analysed fully. And moreover when it comes to how, from what and for what a captain acquires his visual data, the research has hardly been done. This is the report on the dependency of the cues for depth perception on the visual acuity, the distance to the object and visual angle.
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Kohji YAMASHITA, Akio YASUDA
Article type: Article
1996 Volume 94 Pages
117-123
Published: March 25, 1996
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It is indispensable to know the position and the intensity of the typhoon for the safety navigation of ships. This paper presents a new method for automatically estimating the position of the typhoon center using only GMS IR images. The method is based on the fact that the center position of the typhoon is to be a focus of the ridge lines of cloud bands which curves like as a spiral. First, we assume the center position and find the most reliable focus of these ridge lines using tangent lines whose distance from that point is all the same. Next, we regard the reliable focus as assumed center positioin and repeat above operation. We get the center position of typhoon because the assumed center moves toward the true center. Experimental results using GMS IR images show that the method estimates the typhoon center with the accuracy reported in SAREP.
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Hiromune NAMIE, Akio YASUDA, Tomonori OKAMURA
Article type: Article
1996 Volume 94 Pages
125-129
Published: March 25, 1996
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Real-Time Kinematic (RTK) GPS has an ability to fix a position as the cm order by measuring the range from the GPS satellites with the accuracy of the 1/100 order of a carrier wavelength. The authors tried to evaluate the accuracy of the angle measurement of inclination by inferring the accuracy of altitude determination by RTK-GPS. A GPS antenna of user station is mounted on the edge of an oscillating table with 45cm in arm length and about 10s in oscillating period. The temporal variation of altitude agrees very well with the output of the capacitive type clinometer mounted on an oscillating center except the high frequency vibration of about 2cm standard deviation which is measured at the stable condition. The output delay of the fix position is also measured to be 135.90 ms which can be neglected in the measurement of the ship's attitude. The application of the filtering may improve the accuracy in the angle measurement.
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Feng YU, Akio YASUDA
Article type: Article
1996 Volume 94 Pages
131-135
Published: March 25, 1996
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It is pointed out in the Kinematic GPS that the jump of the position and/or deterioration of the accuracy are observed when the satellite number decreases. The authors acquired the cumulative phase numbers of the carrier waves from 7 GPS satellites at both monitor and fixed user stations every 20 seconds. Then they deduced the 2drms's of horizontal distribution of 100 positions in the case of 4 to 7 satellites respectively. The ratio of drms to HDOP value is about 1 cm, which might correspond to the range finding accuracy of the receiver, and almost constant independent of HDOP value and satellite number. It is proved that the reduction of the satellite number brings about the DOP value increase and the accuracy deterioration same as the case of stand-alone GPS and DGPS. This suggests that we need to take care of the DOP value when the satellites are blocked.
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Naoto SATO, Michiko YAMASHITA, Junzou SETO, Yasuhiro OKAMOTO
Article type: Article
1996 Volume 94 Pages
137-144
Published: March 25, 1996
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We have reported that the main towers of the huge suspension-bridge have been considered macroscopically as a couple of the vertical electric dipoles from analyzing the disturbances of the electric fields caused by Minami-Bisan Seto-Oohashi Bridge. In this paper, in order to study the effect of the reradiation from the structure of the bridge extending in the horizontal direction, the vertical electric field intensities of Decca Waves were measured near Akashi-Kaikyou Oohashi-Bridge. When two main-towers were built, the distur-bances of the field intensities appeared slightly. Secondly, as the hauling ropes were built between two main-towers, the shielding of the electric field was caused under the hauling ropes. Further, the sinusoidal-like variations of the erectric field intensities were also seen clearly on the transmitter side of the bridge. By the theoretical considerations, the static capacitance of the main-tower was about 0.003μF, and it became about 0.37μF after the hauling ropes were built. It will be concluded that the capacitance of the main-tower is increased apparently by the horizontal structure of the bridge such as hauling ropes or main cables, and consequently the main-towers radiate the strong secondary waves.
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Kakuichi SHIOMI
Article type: Article
1996 Volume 94 Pages
145-152
Published: March 25, 1996
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Airport Traffic Management System based on Object Oriented Data Base System is prototyped. The prototyped system consists of four engineering workstations connected by network. By using this system airport tower controllers can access all information necessary for airport traffic control and can exchange the information among them. As the results of the simulation carried out under the virtual reality environment of the airport control tower, all instruction of airport traffic control can be done by only using mouse in this system. And each console has been realized the compatibility of the console that will be used to access controller=pilot data link.
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Takayuki ARAI, Akio YASUDA, Isamu TANEZAWA
Article type: Article
1996 Volume 94 Pages
153-159
Published: March 25, 1996
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The authors propose a remote control system which uses the communication line to achieve an automatic operation of the ship. It is necessary to integrate the inormation which affects the ship operation. Recently, the computer system inboard, caled inboard LAN, is established to integrate the information generated inboard. However, the means to treat information integrated has not been established in the communication between land and the ship. Although the e-mail system which is one of communication methods in Internet can treat only the text data, the data of the voice, the image, and animation, etc. can be treated integrated by using the MIME expansion. It is useful for making of the communication between land and the ship to be integrated. However, because only the communication in a single direction is defined in the e-mail system, it will be impossible to use it for remote control of the ship without any improvement. Thus, the design of the remote control system which uses e-mail is examined in this paper. We take remote use of research data processing system installed in Shiojimaru of The Tokyo University of Mercantile Marine as an example of the remote control system of the ship. In this thesis, first of all, the outline of research data processing system of Shiojimaru is introduced. Next, the flow of information by the experiment onboard in the past is brought together and a necessary function for the experiment system is examined. We design the remote experiment system of Shiojimaru which used e-mail based on them.
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Osamu SUZUKI, Akio YASUDA
Article type: Article
1996 Volume 94 Pages
161-167
Published: March 25, 1996
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Teletext is a data transmission medium which uses the space of TV video signal. It transmits characters, figures and sounds with a high rate of 42 kbps. A common TV set can be used with a small apparatus as a receiver and a display. It has the vast service area including coastal area just as that of the TV broadcasting. Thus, it is very effective in transferring the navigational aids information such as NAVTEX, NAVAREA, EGC and etc. to vessels steaming on the Japanese waters. The authors measured a reception rate of the teletext on the ordinary navigational route around the Japanese archipelago. The packet reception rate is more than 90% during the TV transmission hour, presently 6:00〜23:59. The value is good enough to transmit the data, as the teletext is usally sent repeatedly every few minutes.
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Midori TAKAHASHI, Osamu AMAI, Sakae NAGAOKA
Article type: Article
1996 Volume 94 Pages
169-177
Published: March 25, 1996
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This paper describes the method and results of safety assessment for the North Pacific (NOPAC) composite separation route system. The collision risk due to loss of longitudinal separation is estimated using the observation data on traffic flow characteristics. In order to estimate model parameters of the longitudinal collision risk model, flight progress strips and flight plan data were used for analyses. The longitudinal collision risk for a route segment of the R220 (from NIPPI to NUBDA) of the NOPAC was estimated using several data sets. The estimated risk values based on each data set were compared and reviewed.
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Sakae NAGAOKA
Article type: Article
1996 Volume 94 Pages
179-186
Published: March 25, 1996
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The required navigation performance (RNP) is a statement of navigation accuracy of aircraft. The RNP type is represented by 95% containment band of errors. The meaning of the containment band differs corresponding to the dimension of errors, e.g., one-dimensional or two-dimensional. Both dimensions are used for describing RNP types in the aviation world. In this paper, the two-dimensional (circular) containment is compared with one-dimensional one assuming the Gaussian and the double exponential (DE) error distributions. Results and several problems are discussed herein.
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Nobuo ARIMURA, Kazunari YAMADA, Shinobu SUGASAWA, Kenichi YONEHARA
Article type: Article
1996 Volume 94 Pages
187-192
Published: March 25, 1996
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Aiming at improved navigation safety, this paper examines the method for evaluating the safety of collision prevention support system. Watch operation "to spot dangerous vessel and to find relief area" by the person at the steering wheel was simulated on CRT to investigate how the reliability and burden of visual information processing operation were affected by the manner in which the visual information was displayed. ARPA images were simulated on CRT and a series of wacth operations were repeated using personal computer to measure the reliability of visual information processing and the burden of the operation. Following results were obtained. ・Time duration for deciphering the visual information varies depending on how the information is displayed. ・Improved method of displaying the visual information requires less time in deciphering and reduces the burden on the personnel in charge of the operation. ・Reliability of the improved mode of information processing is increased. We were able to obtain valuable suggestions regarding the improvement of the conventional ARPA display.
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Kouji MURAI, WEI Xue, Nobuyoshi KOUGUCHI, Yuichi MIYOSHI
Article type: Article
1996 Volume 94 Pages
193-201
Published: March 25, 1996
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Automatic Radar Plotting Aids (ARPA) is one of the instruments effective for aiding safe navigation in term of collision avoidance. The ARPA informations are well utilized and highly appreciated among watch officers especially when the visibility is limited. But we should remember that the ARPA is not complete yet. It still suffers transfer of target, lost target and other information mishap from time to time. So it remains necessary to study on the accuracy of the ARPA informations. In summer of 1994, we worked on the collection of the radar echo signal data reflected from T. S. FUKAE MARU at 36 aspect angles in smooth sea condition off Marine Practice Center of our school in Awaji island. The received signals are processed by the 8bits, 120MHz A/D converter and stored in the 8 Mbytes memory to find a basic statistical characteristics of the radar echo. In this paper, we propose a Monte-Carlo analysis for the evaluation of the reliability of ARPA information in which the effect of fluctuating target positions on the estimated course is simulated and analysed based on the distribution functions of the fluctuation of the collected peak positions obtained as mentioned above.
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Hisashi MATSUMURA, Shushin SATOH
Article type: Article
1996 Volume 94 Pages
203-210
Published: March 25, 1996
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This paper presents an automatic categorization of documents of cause of collision accidents from the Report of Judgement on Marine Accident Inquiry Agency by term weighting. Term weighting is performed by term frequency and kinds of terms. WIDF (Weighted Inverse Document Frequency) is adopted as a term frequency method. Kinds of terms which are registered in a dictionary for parsing the documents are discussed from technical and general prospects. The results obtained are as follows. (1) 5 kinds of terms which parse the documents are defined. They are terms defined in law, techinical terms, semi-technical terms, complex terms and nouns. (2) Terms defined in law, techinical terms and semi-technical terms plays an important role of categorization. (3) The accuracy of a right answer is about 60% at the maximum.
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Tokuichiro HAMADA, Hisashi MATUMURA, Masaaki INAISHI, Akio M. SUGISAKI
Article type: Article
1996 Volume 94 Pages
211-218
Published: March 25, 1996
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Each user has characteristics in consulting Report of Judgement on Marine Disaster Inquiry Agency. In order to deal with users' different characteristics, the authors propose a retreival system of the Report including user models. User models play an important role in representing users' characteristics. We obtained a lawyer's user model who usually consults the Report. The results of this research are as follows, (1) The system including user models of the laywer was developed. (2) Contents of the Report and users' query sentences can be translated to intermediate language by user models. (3) Reterival can be executed through the intermedicate language.
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Susumu Kuwashima, Hideki Hagiwara, Naoto Iwasaka
Article type: Article
1996 Volume 94 Pages
219-230
Published: March 25, 1996
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A FDR (flight data recorder) of air plane is well known to be a useful instrument to review a flight especially in the case of accidents. But the ship does not have such a useful recorder. That is the reason why such recorder was not essential for ship to merely sail and moreover many sensors to measure phenomena in ocean were not developed yet. But recently an occasion of the accident of Ro-Ro passenger ship [Estonia] in Baltic Sea, the requirement of VDR (Voyage Data Recorder) is on the rise in all over the world. So, we tried to develop VDR with up-to-date sensor and computer techniques. At first we formed a clear conception of VDR with reference to FDR and other recorders. Then concerning about wish of use and desirable function of VDR, we asked intention of users who are in various field of industry including shipping Co. using the questionnaire method. And finally we proposed a modern VDR with many suitable functions for each user based on our own concept.
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Hiroyuki MATSUMOTO
Article type: Article
1996 Volume 94 Pages
231-238
Published: March 25, 1996
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Legal applications are complicate so that laws and ordinances have priority structure, special conceptional structure and unique logical structure, and legal knowledge has the classification such as laws, regulations, precedents, legal theories, legal common sense and so on. Especially maritime traffic laws and regulations were legistlated as legal norm which stipulated custom and empirical rules, and had character with judicial norm other than maneuvering norm (behavior norm). This research has interdisciplinary character as foundations in traditional jurisprudence, symbolic logic, legal logic and information science, and forms one province of jurimetrics aiming at scientific approach of law by empirical method. The idea of jurimetrics can be applied to systematization of laws and ordinances. In this research, I clarify legal knowledge structure and discuss a method theory of systematization for the maritime traffic laws and regulations through an approach of jurimetrics for legal thought.
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Minoru SOMEYA
Article type: Article
1996 Volume 94 Pages
239-247
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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A great deal of notifications are circulated to ship inspectors from the head office. Those state papers are increased year by year. It is very troublesome and timeconsuming for them to keep and refer to a pile of notifications. A database and retrieval system which holds notifications in an electronic form is considered to be effective to help ship inspectors with their routine. In an usual database system, a record is retrieved only with keywords, but approximate or imprecise information stored in our natural databases is also helpful. By fuzzy queries which use fuzzy predicates based on the theory of fuzzy, it is possible to realize more precise and user-friendly document retrieval system than the conventional one. In this paper, a fuzzy document retrieval system for ship inspectors using fuzzy queries is investigated and implemented on a portable computer to show how effective and practical.
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Yuji HAYASHI, Nobukazu WAKABAYASHI, Takafumi NANRI, Hirotsugu WAKE
Article type: Article
1996 Volume 94 Pages
249-255
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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Navigation information is necessary for safe and efficient ship handling. Ship navigators must pick up manually necessary navigation information from a vast amount of them. In this paper, we propose automatic retrieval systems for Japanese nautical charts and sailing directions using an engineering work station (EWS), and develop its prototype. These systems are composed of general purpose database, unified retrieval algorithm and user-friendly interface. The database of nautical charts retrieval system is composed nautical charts attribute data of 781 sheets of Japanese nautical charts in Japan adjacent waters. When the system operator inputs main points of departure, arrival and altering points on the general chart in the EWS's graphic display by its mouse pointer device, the system retrieves necessary charts for the inputted course line. The database for sailing direction retrieval system is composed of 'Seto Inland Sea' sailing direction. The mentioned items of sailing direction are classified to 2,000 areas and items. When the system operator selects the item of operation menus in the graphic display, the system can retrieve and show the necessary information of the sailing direction in the graphic display. When the operators use these systems, they can reduce the operation time compared with manual operation. Of course, they can get necessary navigation information from the database without omission.
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Tatehiko MIKI, Shizuo TAKEMOTO, Hiroshi NISHIMURA
Article type: Article
1996 Volume 94 Pages
257-262
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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Due to the rise in yen exchange rate, dry docking has been usually done outside Japan in order to save the docking budget. Dockyard works other than hull cleaning and paintings, cleaning sea chest and sea valves, propeller polish, etc. are carried out as voyage repairs, which achieve a considerable reduction in the docking costs. Instead, most ship-masters are requested to carry out on board maintenance (OBM) with the ship's crew. In the present paper, docking operations are scheduled in order to cope with increasing OBM jobs. The critical path method (CPM) is applied to the dry docking schedule of the training ship "TOKAI-DAIGAKU MARU II", the following results are obtained : 1. The project scheduling techniques including PERT and CPM methods can be applied successfully to reduce the duration and manpower of docking operations. 2. Spare and/or repair parts should be applied according to the OBM schedule since more and more jobs are going to be carried out on board. 3. The life-cycle cost concept has to be established in order to keep the ship cost-effective within the constraints specified by operational and maintenance requirements.
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Toshihiko MATSUO
Article type: Article
1996 Volume 94 Pages
263-271
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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The purpose of this paper is to consider the change of inland seaborne cargo flow through practical use of local port and then explain a cut of social cost. At first the author showed a state of seaborne cargo in Japan. Secondly the author showed a Huff Model for coefficient of port utilization. This model has the explanatory variables of the number of berths, frequency of call of ports and distances from shippers to ports. According to the model, the author proposed a practical use of local port effective to cut of social cost. The results are as follows ; (1) Seaborne cargo is about 12% of inland cargo in Japan. (2) Huff Model is effective to represent coefficient of port utilization. (3) If shippers make the best use of local port, we will be able to reduce the distance of truck transportation from shippers to port and we will cut the transportation and social cost.
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Nobuo KIMURA, Tsukasa HOKIMOTO, Kinzo OHKOSHI, Kiyoshi AMAGAI
Article type: Article
1996 Volume 94 Pages
273-279
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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In order to study on the safety of fishing operation on the small fishing boat for raising scallops in Funka bay in a severe winter, the authors have measured the wave height on the fishing ground at stormy weather, and the seakeeping qualities. In this paper, the safety is discussed from the stand-points of the wave height and the rolling angle of the fishing boat. We got the following results ; (1) The distribution of power spectra of the movement of the sea surface in the coastal area, whose sea condition is dangerous for fishing operation, exhibits two strong powers, because the movement is consisted of the short periodical wave generated from the periodic wind blowing from the direction of north-west and the long periodical swell transmitted from the Pacific Ocean. (2) The distribution of the wave height in the above condition can be approximated well by using the distribution function of the Beta distribution, although the fitting of distribution functions of the Rayleigh distribution and the Log-Normal distribution are not successful. (3) The results of the fitting to the estimated distribution for the rolling angle of the fishing boats, by using several distribution functions, suggested that the distribution function of the Beta distribution can estimate well the probabillity concerning the safety, although the distribution function of the Rayleigh distribution underestimate it.
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Masayoshi KUBO, Tsuyoshi OKI, Kenji ASAKI, Kazusei YAMAMOTO
Article type: Article
1996 Volume 94 Pages
281-289
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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The authors have proposed an equipment enclosing a hull with curtains for the prevention of spilt oil diffusion. In this paper, the experiments on setting a curtain on board are carried out for various types of the equipment in order to know the way which the curtain can be set as soon as possible and the setting workability is evaluated. The obtained results are summarized as follows : (1) In order to use the equipment practically, a curtain which is rolled up into the shape of a rope should be handled in the setting work and the weights to sink the lower edge of the curtain into the water should be fixed in the final stage of setting the curtain. (2) For the sake of the most practical way on the setting, the stowage of a curtain in the shape of a rope on the shell plate or the handrail around a hull is proposed. On using this stowage, the curtain can be set only by release of the lashing. Therefore, it is expected to set the curtain in a few minutes just after an accident even if weather condition is rough.
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Katsuji YAMAGUCHI, Hiroshi YAMANOUCHI
Article type: Article
1996 Volume 94 Pages
291-298
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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The amount of oil outflow from the inclined bottom damaged model tank with double hull to still water is measured. The 1/50-scale model tank simulated midship section of VLCC is used. The oil outflow is occurred due to (1) the difference between the static pressure in the tank and surrounding water at the bottom damage, and (2) the displacement of oil contained in the double hull space below the damage by water. The experimental results show that (1) the amount of oil outflow is increased with increasing the difference between draft and oil level, and (2) the amount of oil outflow from the inclined double hull tank is larger than the non-inclined double hull tank. The method to predict the amount of oil outflow proposed in the previous report for the non-inclined tank is applied to inclined tank. A comparison of prediction with experimental data shows a satisfactory agreement.
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Shigeaki SHIOTANI
Article type: Article
1996 Volume 94 Pages
299-307
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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This paper is a fundamental research exclusively on wavemaking phenomena generated by a planing flat plate of finite span. In the 6th report, the three dimensional wavemaking phenomena, obtained by the analytical calculations are compared with the experimental ones. These calculations of generated waves are carried out by using the running physical disturbance model on the free-surface. This paper deals with numerical computation by a finite differential scheme on surface waves which are generated by a running pressure disturbance. The computational surface waves are compared with ones generated by a planing flat plate of finite span.
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Katsuhiko SAITO, Masayoshi KUBO
Article type: Article
1996 Volume 94 Pages
309-314
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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The characteristics of motions of a floating body in transient waves are investigated by physical and mathematical model. Having calculated slow drift wave forces, non-linear response of a floating body in transient waves can be solved by time domain calculation method. The mathematical model is verified by comparison with physical model tests including long period oscillations. Qualitative properties of the long period motion in transient waves can be simulated by the mathematical model. The agreements of mathematical and experimental results of the maximum amplitude of short period motions are fairly well. Motions of floating body by transient waves and monochromatic waves are compared. The nondimensional maximum amplitude of short period motions divided by maximum wave height in transient waves are almost equal to the nondimensional motions in monochromatic waves at the same frequency without the resonance state. The motions in transient waves are less than the monochromatic motions near the resonance period, and the tendency is heigh when a damping of motion and a number of carrier waves in transient waves are small.
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Masayoshi KUBO, Yasuo MAEDA, Shinji MIZUI, Yutaka YUMIYAMA
Article type: Article
1996 Volume 94 Pages
315-325
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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At fishery harbors facing to open-sea, we carried out a questionnaire survey which concerns the actual condition on long-period waves. Then a numerical calculation was performed on the basis of the received answers. The obtained results are summarized as follows : (1) As wave group causes the harbor oscillation of high order modes, long-period waves are not amplified so much, and in the harbor the height of long-period waves is about 1/10 times as high as offshore waves. (2) Even at the innermost point of harbor, the energy of long-period waves is not attenuated so much. (3) At fishery harbors facing to Open-sea, a water current and a vortex caused by long-period waves are easy to occur near the harbor entrance. (4) On the area of north side of the Pacific Ocean, ship entering into harbors is hard under a strong seasonal wind and a typhoon. (5) Even if the fishery harbor is facing to Open-sea, it is easy to enter the harbor and moored ships are safe, if the harbor is surrounded by natural geographical features. (6) In the Tohoku region of the Pacific Ocean and west side of Shikoku, most harbors are natural good harbors, and are not affected by long-period waves.
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Mitsuo TADA, Satoshi SUSAMI, Chitose MATSUSHITA
Article type: Article
1996 Volume 94 Pages
327-335
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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Field observation was carried out twice (each 3 days in September, 1994 and in June, 1995) at Hamato Bay in the Yuge Island, located in the middle part of the Seto Inland Sea, to investigate flow patterns of tidal currents using a 1200KHz ADCP. Results of this survey were summerized as follows ; (1) The tidal currents were roughly found to be barotropic at the surveying lines. (2) The geographic eddies were generated around the point B of the AB surveying line owing to the headland effect. (3) At the time of the ebb, the counter currents were turned clockwise at the inside of the bay, and the off-shore currents were roughly found to be formed at the middle part of the bay. (4) In the flood, the counter current were found to flow anti-clockwise along the coast line of the bay.
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Shinsuke ARAKI, Taketoshi YAMADA
Article type: Article
1996 Volume 94 Pages
337-343
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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The transportation by automobile is very important and main mode of cargo transportation, and its modal share takes 91 percent of ton base and also 51 percent of ton-km base in Japan. The importance of automobile transportation will not change in the future. In this paper, we analyze the coordination of volume between cargo and automobile, and then we consider the deregulative counterplan to meet the situations of increasing volume capacity for cargo loading and also reducing the number of large and heavy type automobiles. The coordination of the cargo volume capacity of large and heavy type automobiles is not so good in the relation of loading the consumption goods. We conclude that the volume capacity for cargo loading will be increased and the number of large type automobiles can be reduced by the deregulative counterplan for the height of automobile taking the construction limits of the road into consideration. At the same time, this deregulative counterplan contributes largely to the road haulage of the international high cube containers.
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Article type: Appendix
1996 Volume 94 Pages
App2-
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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Article type: Appendix
1996 Volume 94 Pages
App3-
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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Article type: Appendix
1996 Volume 94 Pages
App4-
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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Article type: Appendix
1996 Volume 94 Pages
App5-
Published: March 25, 1996
Released on J-STAGE: January 15, 2017
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