-
Article type: Cover
1990 Volume 82 Pages
Cover1-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Cover
1990 Volume 82 Pages
Cover2-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Kazunari YAMADA, Nobuo ARIMURA
Article type: Article
1990 Volume 82 Pages
1-12
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
Study on the man-machine system is important for automation of vessel operation. This requires a wide study on the influence of the man-machine effect in ship operation where there are large difference in size, versatile operators and various environment. The objectives of the study is to estimate the man-machine effect through statistical data in vessel traffic flows placing emphasis on the "pass time", T', through a waterway employing two kinds of traffic simulation. The pass time is represented as the specific pass time, T'/T_<0-1>, where T_0 is the pass time without evasive action. Factors which give influence to resulting distributions, such as conditions, for evasive actions are also investigated. The man-machine system is embedded in the dynamic simulation with a computer as: (1) information on the movements of vessels is obtained as a birds-eye view where a "man" is fixed to the earth (absolute coordinate). (2) information on the movements of vessels is obtained as a birds-eye view where a "man" is fixed to a vessel (relative coordinate). The result indicates considerable differences in the specific pass times for two man-machine systems as follows, where the data are averaged values of about 100 vessels. [table] Though the pass times distribute comparatively widely, differences in two coordinate systems are clearly observed and indicate the influence of the man-machine effect.
View full abstract
-
Masanori ISHIZUKA, Hidekazu TAKENOUCHI, Kohei OHTSU
Article type: Article
1990 Volume 82 Pages
13-24
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In 1974 Prof. Mamdani attempted to control a steam engine plant by Fuzzy Control theory and the successful results were obtained. After then, the possibility to apply the fuzzy control theory to wide and more complicate systems has risen rapidly. In Fuzzy Control, the qualitative experience and knowledge that an operator has aquired are described with Fuzzy Control Rule (a form of IF……THEN〜). Therefore, it is possible to design a sophisticated controller which is similar with an operator. In this paper, the authors designed a Fuzzy Controlled Auto Pilot System and carried out an actual trial. The result of the test were statistically analyzed in comparison with the conventional and the human steering. The developed system shown a prudent steering as the able helmsman steered.
View full abstract
-
Shinya NAKAMURA, Yoshitaka FUKUO, Kiyoshi HARA
Article type: Article
1990 Volume 82 Pages
25-31
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
Recently ship maneuvering simulator technique is used to evaluate human factor in order to design usefully berth or harbor establishments. One of important items there is to find such parameters as to express the difficulty of berthing maneuver of captain under given berth arrangement and external forces. Authors proposed a way to find the parameters to evaluate the difficulty of berthing maneuver applying fuzzy regression analysis based on results of simulator experiments. The fuzziness of human judgement was reflected on fuzziness of parameters by fuzzy regression analysis. The results indicated most difficulty of berthing maneuver for captains much depended on the indices of ship motion rather than operational indices.
View full abstract
-
Kuniji KOSE, Hiroki IWASAKI, Shihei NOMURA
Article type: Article
1990 Volume 82 Pages
33-41
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In the previous report, the authors have proposed to introduce the concept of elemental manoeuvres in harbors and studied on manual course-keeping manoeuvres from the viewpoint of evaluating the allowable limit of directional instability of ships. In the present report, an attempt is done to analyze manual course-changing manoeuvres of directionally unstable ships with a special emphasis on the allowable limit of ship manoeuvrability. Carrying out manual course-keeping simulations, two kinds of manual course-changing patterns, bang-bang control and bang-bang control with zero are picked up. In these controls, it seems very important for successful course-keeping manoeuvres to choose a good timing of executing a counter rudder. An error in the timing causes a large error in final heading angle in significantly unstable ships. Then the ratio of the error in final heading to the error in counter rudder executing, or the overshoot angle after executing counter rudder to reaching final heading are employed as parameters to indicate the difficulty in manual course-keeping. The difficulties in course-changing were assessed by helmsmen and the results of course-changing simulations were examined. Both seem to correspond well each other. It is pointed out from the simulation results that the rudder angle becomes significantly large with the increase in directional instability of ships. The maximum rudder angle is frequently applied for ships with large instability. This means ships are deprived of some margin in control power and there is a kind of allowable limit in the sense of safety. The difficulties in course-changing increase remarkably in decelerating conditions because of the decreased effectiveness of counter rudder by reduced propeller revolution. It seems difficult to evaluate clearly the allowable limit of directional instability of ships and further comprehensive investigations are required for making it clear. It can be pointed out that the increase in directional instability deprive a ship of the margin in her control power.
View full abstract
-
Kinzo INOUE
Article type: Article
1990 Volume 82 Pages
43-52
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In order to attain the safer berthing operation in which a large sized ship comes alongside a jetty in lateral motion with tug assistance, it is necessary to investigate how the berthing velocity should be reduced as the ship approaches the jetty. The present paper proposes three types of standardized deceleration patterns of berthing velocity, namely, the "risk averse type", the "risk preferable type" and the "neutral type", which reflect navigators' psychological attitude to the risk. These criteria were derived in the following manner. (1) On the basis of the past records of actual berthing operations of 60 VLCCs, distributions of berthing velocity at each remaining distance to the jetty were identified. (2) Cumulative distributions were divided into three parts of the cumulative percentage of 33.3% and 66.6%. (3) Under the assumption that the berthing velocities within the range of the lower third of the distribution were used by the navigators who were risk averse, the standardized deceleration pattern for the risk averse type was approximated by the curve fitting to the median line of the lower third velocity range. (4) Other deceleration patterns of the "risk preferable type" and the "neutral type" were derived in the same manner by noting the velocity range of the upper third of the distribution and the middle range of the distribution, respectively. The safety of these criteria was ascertained by the assessment model proposed by the author. The most desirable deceleration pattern is chosen by the navigator based on his own sense of safety and thus the safer berthing operation can be achieved.
View full abstract
-
Sakae NAGAOKA, Osamu AMAI
Article type: Article
1990 Volume 82 Pages
53-59
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In the previous paper, we examined the feasibility of 5 NM radar separation minimum in an air traffic control environment where a newly developed Long Range Secondary Surveillance Radar (LSSR) is used. The close approach probability (CAP) was used as an idex of collision risk. Point estimates of CAPs based on two data sets (on the conventional radar and the LSSR) were compared and a positive conclusion was derived. In this paper, we try to validate the conclusion using the data sets from the viewpoint of statistical confidence intervals. We describe methods and results of studies conducted for estimating the distribution of the estimated CAPs by Bootstrap methods. The results made certain that 5 NM separation minimum would be safely implemented compared with the current safety level.
View full abstract
-
Osamu AMAI, Sakae NAGAOKA
Article type: Article
1990 Volume 82 Pages
61-68
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
ICAO has studied the possibility of reducing the vertical separation minimum above flight level 290 from 2,000ft to 1,000ft on the basis of a collision risk model. This paper describes results of calculation on the passing frequency, which is a key parameter of the collision risk model, for a Japanese domestic airway. We estimate the passing frequency by three methods, and compare the characteristics of each method. Finally we evaluate the safety of reducing the vertical separation minimum using the collision risk model. The results show that 1) no remarkable difference is observed among passing frequency values estimated by three methods. The passing frequencies are approximately 3 for opposite direction traffic. 2) an estimated collision risk based on the value is 5×10^<-7> [accidents/flying hours].
View full abstract
-
Kiyoshi HARA
Article type: Article
1990 Volume 82 Pages
69-75
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
The demand of high speed transportation at sea is rapidly increasing to cope with social and economical situation. Author studied the effect of ship speed on safety of collision avoidance maneuver under high speed navigation using a ship handling simulator. Two types of scenarios were designed. One was to study the effect of ship speed on simple encounters with combing such factors as three ship speeds of a craft up to 45 knots, encounter angle and relative velocity to a target vessel. The other was to get a subjective evaluation of operators on high speed navigation in congested waters. The results indicated the safety of the maneuver under high speed navigation increased due to a shorter time of maneuver. The operators paid much attention on the encounter with other high speed crafts in congested waters. This means we have to have concrete measures such as traffic rule or operational manual in order to decrease encounters with other high speed crafts.
View full abstract
-
Hayama IMAZU, Takeo KOYAMA
Article type: Article
1990 Volume 82 Pages
77-84
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
It is very important and necessary to know the critical range (the range at which collision is unavoidable) for collision avoidance by course changing maneuver. In order to obtain the critical range by course changing, it has been found necessary to develop a mathematical model of collision avoidance and occurrence. We have used a new analytical technique, using an area of collision target's position. And different versions of the critical range by course changing are obtained under assumptions such as a) one ship evades, while the other stand on. b) one ship evades while being pursued by the other. The study shows that the critical range by course changing depends strongly on the two ship's speed difference, and on the permissible maneuver.
View full abstract
-
Hajime KUROKAWA, Hayama IMAZU
Article type: Article
1990 Volume 82 Pages
85-91
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In case of collision avoidance, information about targets is obtained from a radar system or through the sense of vision and hearing. Especially, the information through the sense of vision is very wealthy. However, the study of machine perception concerned with the sense of vision is delayed, it is the present condition that the practical collection of visual information is leaved entirely to persons under the actual navigation system. In this paper, first, we classified the information required the estimation of encounter conditions with other vessels. Next, by using of image processing techniques, we tried to get out of the picture related to a part of hull from a color photograph which had a scene of a vessel on the sea, and extracted some features from the processed image. After then, we attempted presumption of the visual information in accordance with the extracted features.
View full abstract
-
Nobuo ARIMURA, Kazunari YAMADA, Norikazu OHNISHI
Article type: Article
1990 Volume 82 Pages
93-101
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
This report is a study on a navigation decision support system to aid the safe navigation of marine vessels. Presently navigators rely on visual observation for information concerning the navigation area and do not effectively utilize radar information. Consequently, the vessel collision rate is high due to limited visibility in fog and at night. In order to verify the navigation decision support information for the Navigation Area Hazard Display System. A simulator experiment was conducted varying the navigation characteristics on the display system. The navigation area information system has 3 types of hazard displays: relative movement vector display, relative movement and actual movement vector display, blockade indicat or contour line display. When this system was compared with conventional relative movement vector display systems in a simulator experiment, the Navigation Area Hazard Display system blockade indicator was effective in reducing the accident rate and protecting the blockade zone.
View full abstract
-
Kenji NIIMI, Minoru ITO, Tatsuto YAMADA, Akira ISHIDE, Kazuaki HOSHINO ...
Article type: Article
1990 Volume 82 Pages
103-111
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In order to provide small ships with satellite communication, small antenna and digital communication technique are necessary. So we carried out the experiment of the propagation characteristics of 2.4〜4.8kbit/s data and digital voice communication using short backfire antenna of 40cm in diameter, in Japanese waters and the Indian Ocean. The results of this experiment are shown as follows; 1) Even in rough sea, fading range (signal accumulative level from 99% to 1%) was about 1.6dB in satellite elevation angle above 43°and about 7dB in low elevation angle of 9°.2) Spectrum of received signal level had three peaks. These were 0.002〜0.008, 0.01〜0.1 and above 0.1Hz. The peaks of 0.002〜0.008 and 0.01〜0.1Hz were caused by ship's rolling and pitching. The peak above 0.1Hz was caused by multipath fading. 3) Even in low elevation angle, experimental digital voice communication gave the good results at C/No of 46.5dBHz and bit error rate of 10^<-3>.
View full abstract
-
Akira ISHIDE, Mitsuhiro FUJITA, Hideomi NASU, Kazuaki HOSHINOO, Minoru ...
Article type: Article
1990 Volume 82 Pages
113-119
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
This paper describes the result of data communication experiment using a Boeing 747 cargo aircraft and Engineering Test Satellite V (ETS-V) conducted to develop and evaluate satellite data communication techniques for oceanic air traffic control. Circular patch antennas (peak gain: 7dBi) on board the B747 were used for transmission to and reception from the ETS-V. The B747 flew between Narita and Anchorage where the satellite elevation angle varied from 10°to 45°.Data transmission characteristics for three modulation schemes, BPSK, SS and PM, were measured and compared with theoretical ones. The result showed the followings. The degradation of data transmission characteristics were within the link margin for all modulation schemes. For BPSK (without FEC), transmission errors considerably increased in the eastbound flight due to signal level variation caused by the reflection on a wing. But, the increase of transmission errors was relatively small in the westbound flight for all modulation schemes.
View full abstract
-
Tatsuto YAMADA, Minoru ITO, Kenji NIIMI, Akira ISHIDE, Kazuaki HOSHINO ...
Article type: Article
1990 Volume 82 Pages
121-128
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
This paper describes the principle of the experimental ranging system and the result of the ranging experiment using the ETS-V. The ranging system uses multiplexed burst signals of sinusoidal tone and data with 0.5sec duration. The distance between the ETS-V and ships is obtained by measuring the phase delay of the sinusoidal tone for fine ranging and the time delay of the data for ambiguity resolution in the ranging equipment. The ranging experiment was carried out on the South China Sea and the Indian Ocean in 1989. Satellite elevation angles in these areas were 45°and 14°, respectively. The signal acquisition time of less than 193.3 msec could be obtained for the C/N_0 of more than 42dBHz at both elevation angles, but it varied widely for the C/N_0 of less than 44dBHz due to multipath fading when the elevation angle is 14°. The ranging accuracy of less than 50m rms could be obtained for the C/N_0 of more than 42dBHz and the characteristics of the ranging accuracy showed the degradation of about 2.5dB in C/N_0 compared with theoretical value.
View full abstract
-
Hajime CHIBA, Akio YASUDA, Heiichiro ANDO, Katsuhiro YAMASHITA
Article type: Article
1990 Volume 82 Pages
129-137
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
A simple, two-axis controlled, satellite tracking antenna for vessels, which has been designed by the present authors originally for satellite broadcasting, is applied to the reception of images from the geostationary meteorological satellite on board. Instead of an expensive vertical gyroscope, small and inexpensive pendulum-type inclinometers are used as sensors for rolling and pitching, which require some adjustment of the obtained values. A rather small parabolic antenna of 0.75m in diameter is used to lighten a load due to wind pressure. The allowable angular error increases, though carrier power at the receiver decreases owing to the reduced aperture area. The nominal value of noise figure of the pre-amplifier is 1.8dB. The device was tested for receiving images on a ship which steamed around the Pacific Ocean. It was proved that the images received by the present device were satisfactory in the vast area with elevation angle down to 30°covering Sakhalin in the north and New Zealand in the south. The multi-path fading was often observed in the area lower than 25°. An antenna with larger aperture will expand the area by increasing the reception power and decreasing the fading.
View full abstract
-
Shogo HAYASHI, Yukito IIJIMA
Article type: Article
1990 Volume 82 Pages
139-146
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
The MINAMI and KITA BISAN SETO OOHASHI which are representative large bridges were constructed in the SETO inland sea. These bridges cause false reflections to be displayed on radar screen. Preventive measures to reduce dangerous false reflections has been taken. These measures include the improvement of bridge structure design and the installation of reflection plates or specially developed absorbing materials. This paper describes experimental results obtained from an actual anchorage of bridge which has special construction as the inclined special wall. The following conclusions were obtained. The reduction of false reflections using special inclined wall was 3〜17dB for the one way. It is evident that there is a good effect on the special inclined wall.
View full abstract
-
Manami IDE, Shogo HAYASHI
Article type: Article
1990 Volume 82 Pages
147-152
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
When we are encountering many vessels at sea, it is very useful that the information on these vessels, for example, course, speed, size of vessel, destination and intention of maneuvering, can be obtained instantly. Some of these information are provided by a navigational aids like an ARPA. But it takes at least a half minute to observe the vessel and to calculate the vessel's course and speed, also it is an old value of a half minute at least. The authors made attempt to estimate gross tonnage, shape and aspect angle of the vessel by simple image processing of radar echoes. An ultra high speed analogue to digital converted echo images of radar gives us special information not as before. The experiments were practiced using the X-band radar with narrow beam width antenna. The aspect angles of the vessel were able to estimate in relative certainty. The characteristics of radar echo are thought as follows. There are many constructions like as bridge house, derricks, fore castle and others on the upper deck. The radar image is influenced by these constructions. Some echoes are strong intensity because of large reflection areas, and one another echoes became long blip because of multiple reflection into the constructions. The authors think that it will be possible to estimate characteristics of vessel from these clue to analyze. Furthermore they are also thinking the images using radar are similar to the image with naked eye in some point, and it is possible to estimate the characteristic of vessels.
View full abstract
-
Kuniaki SHOJI
Article type: Article
1990 Volume 82 Pages
153-164
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Masayoshi KUBO, Katsuhiko SAITO, Tsuyoshi OKI
Article type: Article
1990 Volume 82 Pages
165-171
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
When a mooring ship receives a strong land wind, the ship is separated from quay wall and then interruption of cargo handling and cutting of mooring rope are often resulted consequently. As a new countermeasure of the problem, we proposed a system where the water pressure resulted from the difference of the water level of both ship's sides is utilized. In this paper, we carry out wind channel tests in order to investigate the applicability of the system to a real ship and to extract the problems of the system. Some points to be improved in the system are clarified by the experiments.
View full abstract
-
Masayoshi KUBO, Katsuhiko SAITO, Shigeki SAKAKIBARA
Article type: Article
1990 Volume 82 Pages
173-180
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
Authors proposed the strip method of ship motions moored along quay walls. But its calculation method is not good in quartering seas. It is considered that the estimation method of the exciting forces is not appropriate in that case. In this paper, an improved calculation method of the exciting forces is proposed and the experiments of moored ship motions are carried out to verify the method.
View full abstract
-
Masayoshi KUBO, Katsuhiko SAITO
Article type: Article
1990 Volume 82 Pages
181-187
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
In recent years, feasibility studies of floating quays are carried out frequently. In this paper, particularly, concerning with the motions of two floating bodies, the two-dimensional analysis and the experiments are carried out. The obtained results are summarized as follows; (1) The agreements between the theoretical and the experimental results of the motions of two floating bodies are fairly well. (2) The vertical and horizontal relative motions between two floating bodies vary with the spring constant of a mooring facility and the distance between quay wall and floating bodies. (3) On design of a floating quay, it is important to consider the characteristics of the motions of two floating bodies moored along the quay wall.
View full abstract
-
Hiroyuki SHIMADA, Mitsuo YOSHIDA, Takashi KURODA
Article type: Article
1990 Volume 82 Pages
189-196
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
Attitudes towards school work, friendship, leisure, occupation and the sea among mercantile marine students were measured by using questionaire methods. The quantification method III was applied, and categories' weight were classified into 2 axes (Factor I and II) which denote positive interests towards the sea and positive attitudes toward the college.
View full abstract
-
Rihei KAWASHIMA
Article type: Article
1990 Volume 82 Pages
197-206
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
Using the method given in the previous paper, the author has been analysed the ship's rolling motion in wind waves by the model experiments. The coefficients of nonlinear differential equation for the ship rolling motion at sea have been deduced from the experimental data and solved by Runge-Kutta method for Froud-Krilov forces described in various functions. Based on both of the solutions of equation and the experimental results, statistics, power spectra and Poincare mapping functions have been calculated. The utilities of the mathematical model for the ship motion in the experiments have been discussed.
View full abstract
-
Article type: Appendix
1990 Volume 82 Pages
App1-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1990 Volume 82 Pages
App2-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1990 Volume 82 Pages
App3-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1990 Volume 82 Pages
App4-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1990 Volume 82 Pages
App5-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Cover
1990 Volume 82 Pages
Cover3-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
-
Article type: Cover
1990 Volume 82 Pages
Cover4-
Published: March 20, 1990
Released on J-STAGE: January 15, 2017
JOURNAL
FREE ACCESS
