The Journal of Japan Institute of Navigation
Online ISSN : 2187-3275
Print ISSN : 0388-7405
ISSN-L : 0388-7405
Volume 47
Displaying 1-18 of 18 articles from this issue
  • Article type: Cover
    1972 Volume 47 Pages Cover1-
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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  • Article type: Cover
    1972 Volume 47 Pages Cover2-
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
    JOURNAL FREE ACCESS
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  • Article type: Appendix
    1972 Volume 47 Pages App1-
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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  • Y. Matsuno, T. Genga
    Article type: Article
    1972 Volume 47 Pages 1-11
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    The time differences of Loran-A rates (2S6, 2S7, 2H6, 2H7) were measured at the fixed points of Hiraiwa, Sumiyoshi, Toi and Kadokura on the southern Kyushu. The following results were obtained upon the investigation of the velocity of propagation as the Loran-A Ground Waves passed over the sea-surface ; 1) It was confirned that the velocity of propagation of Loran-A Ground Waves over the sea-surface are faster than that of the standard waves used on the computed Loran-A Ground Wave table. 2) When the fronts which extend from a well developed extratropical cyclone exist on these particular routs of propagation, there are common phenomena of noise or fading and accurate measurment may be hard or impossible. 3) It is surmised that the velocity of propagation of the Loran-A Ground Wave is faster in proportion to the sea-surface when the temperature rises. In the southern waters of Kyusyu, it is suggested that the value of ground wave correction may be stated with the empirical equation Y=-0.000233X. (Y...deviation in micro second, X...sea-surface temperature coeficient). 4) When a Loran-A ground wave passes over the area of Kuroshio, it is surmised that the Loran-A signal will be somewhat delayed. It is supposed that the delay-rate is 3.2 micro seconds per 100miles over the area of Kuroshio.
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  • K. Taguchi, H. Kawahira, K. Nishimoto, S. Nakane, Y. Nakajima, H. Sato ...
    Article type: Article
    1972 Volume 47 Pages 13-21
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    In fall of 1971, the evaluation test of the Kita-Kyushu Decca chain was simultaneously conducted at four site in the western parts of the Seto Naikai which is similiar to that of 1970. Moreover field strengths of the master station (85kHz) were measured at two points of the fours with continuous recordings. The principal conclusions obtained during two years can be summarized as follows ; 1) The phase deviations of all patterns varied from year to year and from site to site. 2) The big deviation (about 1 lane or more) was obtained at the site (Nada) where, closed to the bush hill. 3) To the contrary, the fluctuation of the phase difference at each site changed at constant rate, this suggesting the annual rateexist. 4) The field strengths observed were associated markedly with the theoretical value of day and night respectively, in addition, the close agreement was also shown between the phase fluctuation of the Purple pattern calculated and the strength at Nagahama observed. 5) Since the sudden change on the field strength at pre-sunrise effect was continued to 78° of solar zenith angle, all the nocturnal phase difference variations did not set the steady state of the groundwave condition. In order to reduce the effect of the nocturnal phase variations the method like the differential OMEGA was applied. The accuracy of the LOP will be able to improved 30% or so.
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  • S. Matsuo, K. Taguchi, H. Yoshimura
    Article type: Article
    1972 Volume 47 Pages 23-33
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    OMEGA trans-Pacific experiments were made by the two ships separetly during fall of 1970 (Fig 1). Using two receivers over the voyage on each ship, the one was for 10.2kHz and the other 13.6kHz respectively, these examinations were carried out. The difference between 10.2kHz and 13.6kHz on the fluctutation range of phase/phase difference could not find clearly, because the micro change of phase in accordance with the moving ship was not obtained easily. The accuracy of the each OMEGA hyperbolic line in the Bering Sea and the Alaska Bay, would be improved within 1nmi without any relation either night or day under normal condition. The fluctuation range of A-C pair in nighttime was more stable than that of daytime. The reason why might be due to the propagation path of Aldra acrossing the Arctic Zone was stable. According to the field strength pattern of Haiku, the following result was obtained that the difference of propagation path such as east or west, and the difference of the attenuation rate in day-and-night pattern was markedly. The transit time of day/night in the waters of the meridian of Haiku was synchronized completely with the diurnal field strength. It was found that the best way to detect SPA under ship moving is to use the record of field strength. The propagation disturbances were observed 55 times during the voyage via Bering Sea, and these continuous time was 2-51 mininutes. These phenomena could be classfied into SID (SPA) and VLF sferics. Some disturbances caused by SPA, in the case of OMEGA System, suggested that the phase lag in phase difference neverthless the phase advances in phase. Most of VLF sferics were occured in the Area 09, especially near Attu Island and Kamchatka Penn. Nearly all of the field strength of Aldra during VLF sferics were observed suddenly change, on the contrary that of Haiku were disturbed sometimes. The relations between magnetic indicies Kp and the sferics did not found. The disturbances excluded the solar flare were presumably to be weak VLF emission and the strong polar atmospherics with the record of the spectrum obtained by a VLF wide band receiver.
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  • A. Nishino, K. Kimura
    Article type: Article
    1972 Volume 47 Pages 35-44
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    The 138, 000 DWT tanker "SEIKO-MARU" is the first computerized vessel in Japan. The automatic position fixing system of this vessel consists of a NNSS (Navy Navigation Satellite System) receiver and a Dead Reckoning Position Calculator (DRPC), and these two equipments are connected to the same central computer, TOSBAC 3000S. Authors obtained the records from this system at sea, and evaluated the following items ;- (a) frequency of the position determination by NNSS, (b) difference of the dead reckoning position by DRPC from the NNSS position, (c) state of scattering of the NNSS position from a straight course line, (d) state of spreading with time of the dead reckoning position by DRPC.
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  • Y. Matsuno, M. Tsurudome, T. Genga
    Article type: Article
    1972 Volume 47 Pages 45-52
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    The local attraction in Singapore strait and Malacca strait was investigated on board the Keiten Maru, Kagoshima University in 1970 and 1971. The following results were obtained ; 1) The existence of local attraction was confirmed in Singapore strait and Malacca strait. It has been deduced that there are no grave dangers, because the maximum value of local attraction is about 3゜ and the average value is about 0゜.7. 2) The local attraction is distributed as next stated ; It is Easterly in the region between 98゜-30'E and 102゜E, and westerly to the west of 97゜E and to the east of 104゜E, and there are both values in the regions between 102゜E and 104゜E and between 97゜E and 98゜-30'E. 3) It is believed that the east side of Sumatra and Pulau Penang are magnetized in Red, and the west side of Malay Peninsula and the Northern extremity of Sumatra are magnetized in Blue. 4) It is surmised that the variation in local attraction is affected by sea bottom topography.
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  • H. Kikutani, A. Iwai
    Article type: Article
    1972 Volume 47 Pages 53-62
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    We had reported in the previous paper on the statical conditions (in case of strong wind). This paper is the report of experiments on the dynamical conditions. Equipments of experiments, model ship, ship's mooring arrangements (A and B type), water depth are as same as in the previous paper. Cases of experiments on wind and waves are as follows: Wind velocity 35m/sec in actual ship [table] Some results of this experiment are as follows: 1) Periods of fluctuation of tensions of mooring ropes and loads on dolphins mostly equivalent to periods of waves. 2) Ships motion, tensions of ropes and loads on dolphin are mainly effected by wave length and they become larger as length of wave grows longer. When the length of wave is the same, they become larger as height of wave grows higher. 3) We can not moored ships safely when the length of wave is more than one third of ship's length. 4) When a berth is affected by waves, it is necessary that the ship is moored parallel to the direction of wave. 5) Mooring in waves, we can not say certainly that it is better to keep deep draft. When the ship is moored broadside to waves, loads on dolphin are larger when draft of ship is deeper. 6) When length of wave is smaller than one third of ship's length, B-type method of mooring is better than A-type. But length of wave is larger, A-type is better.
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  • K. Onari, A. Iwai
    Article type: Article
    1972 Volume 47 Pages 63-71
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    This paper relates to some experiments with respect to the drifting speed of inflatable type life raft under the wind. Tests were carried out for model in the wind-tunnel with water tank and for actual raft at sea. Raft is used and that principal dimension and experimental conditions are shown in table 1. Hydrodynamic and and aerodynamic forces are measured in model test and the drifting speeds are observed in model and actual experiments. The tests results are as follows ; 1) The aerodynamic force increases with the square of wind speed linearly and the coefficients of the forces are shown in fig.1. 2) The hydrodynamic force increases with the square of drifting speed and the coefficients of the forces are shown in fig.2. 3) The drifting speed caluculated with the balancing of the aero and hydrodynamic forces is good agreement with the speed obtained by the drifting experiments of actual raft at sea. 4) The effect of sea anchor against the drifting of raft is not so expectable in practise as shown in fig.4.
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  • G. Fujisaku
    Article type: Article
    1972 Volume 47 Pages 73-78
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    The main considerations of this paper are as follows : (1) The defects of Rules 25 (c) and 26 in Collision Regulations when putting these Rules into practice. (2) A positive measure in realizing the principle implicit in Rule 25 (c) and its theoretical construction. (3) The dangers in applying Rule 26 to vessels not in sight of one another.
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  • A. Kandori
    Article type: Article
    1972 Volume 47 Pages 79-91
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    The recent abrupt increase in the sea accidents was due to the increasing marine traffic congestion for the purpose of supporting our rapidly developed economic activities. It is of urgent necessity to establish a countermove for the accidents, especially for the collision. The causality, of the accidents is complicated and differs case by case. Respective cases of accidents were examined in detail with much effort and time. But there lacks a consideration in broad aspects. And this report dealt, statistically, with the influence of the meteorological conditions on the frequencies of the collisions occurred in the Kanmon Strait during the period from 1962 to 1969. And the results obtained were summarized as follows: 1. The collision inclined to occur under the wind from SE or from NW, and that of weaker than 1.6m/s (especially, for the ships smaller than 3,000G.T. in the eastern half) or stronger than 10.8m/s (especially, in winter and spring, in the central area, for the ships smaller than 1,000G.T.) 2. More than 70% of the collisions occurred under the good visibility (better than 4km). When the different time length according to the visibility was taken into account, the poorer visibility than 4km inclined to induce the collisions (especially, in winter and spring, in the Hayatomo Seto, the western and the eastern areas, for the ships of the 100 to 1,000G.T. class). 3. The number of collisions per unit time under the poor visibility (poorer than 2km) was about 8 times as large as that under the good visibility (better than 2km). 4. The ships of the 100 to 1,000G.T. class were concerned with about 80% of the the collisions under the poor visibility; and about 55% of the collision under the poor visibility were those by the pair of the ships of this class. 5. The collision rate per ship passed (P_<PV>) under the poor visibility increased in accordance with the size of ship (x in gross tons) keeping the following relation: P_<PV>=0.10x^<0.79>×10^<-4> 6. The size of the ship had a clear relation to the influence of the visibility. Namely, the value of P_<PV> was 2.17x^<0.20> times as high as that under the good visibility.
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  • K. Hara, K. Honda, S. Matsuki, T. Hashimoto
    Article type: Article
    1972 Volume 47 Pages 93-102
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    Based on the queing theory, authors have constructed the mathematical model which describes the marine traffic system where pairs of ship's routes with opposite directions and apart by arbitrary distances cross each other. At each crossing point the effective traffic intensity (the ratio of an arrival rate of ships to an effective passable rate) and probabilities of collision avoidance have been analytically derived from the model. They are numerically simulated by means of a computer, changing such parameters as the traffic intensity and the number of ships between two crossing points. Numerical analyses indicate the critical traffic intensities at which ships jam up on every route. The computed probability of the collision avoiding compares favorably with the actual rate of avoiding collision maneuvers which were observed on board at the congested water in Japan.
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  • R. Oshima, Y. Fujii
    Article type: Article
    1972 Volume 47 Pages 103-108
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    The evasion diameter for vessels going either in the same direction or in the opposite direction has been well studied. Here, one year long survey was performed on marine traffic in the Bisan Seto to obtain the evasion diameter for crossing vessels which is very important for the estimation of the traffic capacity of crossing area. The result of observation from the bridge of Daisan Ukomaru, a ferry navigating in North-South route, yielded (1) the density of vessels either east bound or west bound to be about 2.4 per square miles, and (2) average number of evasive motions per one crossing to be 1.15. The evasion diameter for crossing was calcualted using above values and the average speed and it is about 12L where L is the average length of vessels. More detailed analysis gave (11.5±1.5) L for the diameter.
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  • T. Inoue, H. Wake, T. Yamada
    Article type: Article
    1972 Volume 47 Pages 109-115
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    In the North Pacific, one of the worst sea condition is occurred in a typhoon as well known. But the knowledge of wave distribution of typhoon has been insufficient mainly due to the lack of observed data. There are, of course, many methods and models to obtain the wave distribution. This paper presents the numerical results computed by the new spectral method, Inoue's model, and describes the differences occurred among Unoki's model, Ijima's method, and ours. Although a symmetrical wind field is used, the computed wave height distributions show no contradiction with the empirical pattern, and following conclusions are obtained, 1) generally, high wave height is seen in the right hand aft quadrant, 2) the faster a typhoon center moves, the more aft high wave height area exists, 3) as the center moves fast, wave heights decrease in all quadrants, 4) in the left hand fore quadrant, the effect of 3) is dominant, and in the right hand aft quadrant, less effect of 3) is seen, that is, wave height decreasing is not big.
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  • Article type: Appendix
    1972 Volume 47 Pages App2-
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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  • Article type: Cover
    1972 Volume 47 Pages Cover3-
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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    Download PDF (51K)
  • Article type: Cover
    1972 Volume 47 Pages Cover4-
    Published: August 30, 1972
    Released on J-STAGE: January 15, 2017
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