• Journal of the Korean Institute of Navigation
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• v.7 no.1
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• pp.33-62
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• 1983

A navigator on bridge needs to know every kinds of motion characteristics of his vessel at sea. Generally when a vessel is completely built, the shipyard makes turning circle diagrams from the results of turing circle tests made during the sea trials for the reference of the vessel's owner. But referring only the data of a turning circle diagram, an officer on bridge can not figure out his vessel's maneuvering characteristics sufficiently, So nowadays the shipyard often adds Z test to turning circle test for more detail references. In this paper the author made Z and turning circle tests at the rudder angles of 15 and and 35 degress separately and in each of the case made a turrning circle diagram from the results of the turning circle test and the esults numerically calculated from mathematical formula made on the base of the maneuvering indices got from the Z test and compared them each other for the purpose of finding the correlations between them. Followings are concluded from the results. An actual turning circle diagram and a calculated one from the results of the Z test at same rudder angle coincides each other well when the center of the calculated circle is transferred by 1.7B toward the direction of the initial turning perpendicularly to the original course and 0.5L toward the direction in parallel with original course in case of the rudder angle of 35 degrees and 1.2B and 0.3L toward each of the above mentioned directions in case of rudder angle of 15 degrees.

• Journal of the Korean Institute of Navigation
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• v.3 no.1
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• pp.1-17
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• 1979

It is very important for both naval architects and ship's officers to know the maneuvering characteristics of their ships. As the abilities of a rudder which controlls a ship can be determined clearly by analyzing the results of Kempf's zig-zag maneuver and directional stability of a ship also known by Dieudonn spiral maneuver, the importance of turning test which takes much time is recently apt to be neglected. But because the test can be executed comparatively more simply than any other maneuvering tests, it gives some informations on the directional stability, and turning characteristics may be expressed simply by the results of the test, it is still often performed. In this paper several assumptions are made to simplify the turning motion of a ship. The equations of initial transient phase, the radius ofsteady turning circle, and the center of the steady turning point are derived by using the hydrodynamic derivatives. And then the approximate method of drawing the turning circle geometrically is suggested.

• PNF and Movement
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• v.9 no.1
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• pp.65-73
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• 2011

Background : This study was to investigate effect of hot and cold water for the hand dexterity. Methods : A total of 37 subjects having hemiplegia(men=6, women=11) and normal(men=10, women=10) were participated in this study. After both hands was soaked in the small tube for 1 minute, we measured 'making dots in circles(BOTMP)', 'lifting small objects(JHFT)', 'disk turning(MMDT)' test. Results : In the case of normal's dominant hand, there were statistically significant differences in all tests after soaked in the hot water but there were statistically significant differences in 'disk turning' test after soaked in the cold water. In the case of hemiplegia's unaffected hand, there were statistically significant differences in 'disk turning' test after soaked in the hot water but there were statistically significant differences in 'making dots in circles', 'disk turning' test after soaked in the cold water. In the case of hemiplegia's affected hand, there were statistically significant differences in 'lifting small objects', 'disk turning' test after soaked in the hot water but there were statistically significant differences in 'making dots in circles', 'disk turning' test after soaked in the cold water. Conclusion : The hot and cold water were affected in the hand dexterity. Especially, in the case of both normal and hemiplegia, there were statistically significant differences in 'disk turning' test after soaked in the cold and hot water. Therefore, We were founded that affected in gross movement than fine movement.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.1
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• pp.59-67
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• 2009

It is necessary for navigator to understand sufficiently maneuverabilities based on experiences and the data which were gotten from several tests of the ship when he maneuver his vessel. By the way most navigators used to rely on his experiences or feelings only maneuvering ship. But when he encounters situations he did not experience before he may be in difficulties. So navigator must get both experiences and data based on experimental results. In this paper author performs several tests such as turning test, Zig-zag test and spiral test to provide informations of maneuverabilities for navigators. The obtained results are as follows: There occurs almost no difference in size of the turning circle by the changes of ship's speeds. The scale of the turning circle was decreased exponentially when the rudder angle was increased. The maneuverabilities is better turning to starboard side than to port side. Maneuverabilities are more effective when the rudder is used to small angle than to large angle. As a result of spiral test course stability was comparatively seemed to be good.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.1
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• pp.61-70
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• 2015

In an attempt to improve the maneuvering character of hull form renovated tuna purse seiner. A renovation was carried out on the 3 tuna purse seiner fishing vessel. To grasp the progress of maneuvering and resistance on ship B (730 ton class), new bulbous bow was only attached. The ship A (740 ton class) and C (600 ton class) were modified for new bulbous bow, enlarged slipway and rudder. And then the zigzag and the turning test were carried out. According to the turning test, the advance and the tactical diameter were improved very much for the modified ship. The sea trial was carried out for the original and modified ship A. It is showed that the results of sea trial corresponded with that of the tank test on the whole. In the result of the zigzag test on ship B, the turning ability was improved very much, but the yaw checking ability was deteriorated in just some degree. In the result of the zigzag test on ship C, the turning ability and yaw checking ability were remarkably improved. Ship C was greatly improved among the three ships for the maneuvering character of modified hull form.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.3
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• pp.276-285
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• 2017

The research vessel NARA equipped with an azimuth thruster system was built in 2015. There are few vessels with this propulsion system in Korea. This vessel has two modes such as the normal for maneuvering and the power for investigation, and the other two modes as one axis and two axes on the operating. This type of vessels does not seem to have a clear grasp of the maneuvering character in comparison with the vessel with a conventional propulsion system. So the authors carried out the sea test for the turning, the zigzag and the inclination, and the results are as follows. In turning test, the case of using the two axes mode is much better than the case of using the one axis mode for the elements of turning, such as advance, transfer, tactical diameter and final diameter, but turning hard over the rudder in full speed is very vulnerable to capsize in both modes. In zigzag test, the yaw quicking responsibility index, T is very large excessively, which means a bad counter maneuvering ability, so an operator has to keep in mind that in turning operation. If necessary to avoid collision at head on situation, it may be a more effective method to use the crash astern stop than the turning according to the conditions and circumstances for the shortest stopping distance is very short.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.48-54
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• 2017

A minimum turning circle test of vehicles is operated by using Real-Time Kinematic(RTK) surveying method which enhances the precision of the Global Positioning System(GPS). A procedure of the conventional method to obtain results is to take post processing after the test. Therefore, it is difficult to ensure results in an instant. This paper introduces developed process and equipment that can immediately obtain results after the minimum turning test without post processing.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1865-1871
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• 2015

Ship's trim is the one of the most important factor for safety at the sea. Turning circle test and Z-test were carried out to find the effect of ship's trim and draft changes. The results are as follows. 1. If the ship's draft and trim became large, turning circle would be wide. 2. If the ship's draft and trim became large, ship's drift angle would be small. Small drift angle made wide turning circle. 3. Trim by the head made slow ship's final speed when turning circle test. 4. By Z-test, the deeper draft and trim by the stern made small OSA. Small OSA means strong ship's stability. 5. Totally 2nd OSA is smaller than 1st OSA on Z-test. 6. There were small differences of 2nd OSA in trim by the stern, but there were large OSA in trim by the head. 7. The larger trim by the stern, the smaller OSW. The small OSW means better ship's stability and maneuverability.

• Physical Therapy Korea
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• v.23 no.2
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• pp.11-19
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• 2016

Background: In the stroke patients with the characteristics of hemiplegic gait, turning direction of the affected and unaffected side influences turning time. Therefore, it is important to investigate the walking response to turning directions in stroke patients. Objects: This study aimed to measure the walking time while turning direction in hemiplegic patients depending on balance ability measured by Berg Balance Scale. Methods: A group of forty-five subjects with stroke (Berg Balance Scale score${\geq}46$ were twenty-eight, Berg Balance Scale score${\leq}45$ were seventeen) were enrolled in this study. Subjects were asked to perform the Timed Up and Go test. Testing indications included two directions for turning in each subject. These indications were for turning toward the affected and unaffected side in stroke patients. The duration of total analysis duration, sit to stand phase, stand to sit phase, mid-turning phase, and end turning phase were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 45 points of Berg Balance Scale score. The significance level was set at ${\alpha}=.05$. Results: There were significant increase time in the analysis duration and end turning phase duration while subjects were turned the unaffected side in stroke patients that presented a Berg Balance Scale score${\leq}45$ (p<.05). However, the comparison between the affected side and the unaffected side in the stroke patients with Berg Balance Scale score${\geq}46$, revealed no significant differences of the measured parameters. Conclusion: This finding should be suggested in the specific definition of turning direction for evaluation with Timed Up and Go test in the Berg Balance Scale score${\leq}45$, and other intervention for hemiplegic patients need to be suggested the direction of turning during walking training program.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.2
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• pp.22-30
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• 1986

It is very important for a navigator on bridge to know the maneuverability of his ship sufficiently at sea. Generally, the data of a turning circle test have long been used to study and evaluate the maneuverability of a ship. But referring only the data of the turning circle test method, he can not evaluate his ship's maneuvering characteristics sufficiently. So nowaday the test method added Z test to turning circle test for more detail references is considered to be desirable. In this paper, the authors performed PAL test and Z test together in order to study the maneuverability of M. S.Pusan 403, training ship of the National Fisheries University of Pusan. According to the results of PAL test, the rudder effect in port rudder angle of the M. S. Pusan 403 was found to be more effective than that in starboard one, because her changing amounts of angular velocity, turning radius and tangent speed in port rudder angles were found to be larger than those of them in starboard rudder one in unsymmetry. The relation between her drift angle(.8) and rudder angle (0) was found to be changing with .8=0.640 in direct proportion. As it appeared that her calculated K'-values were smaller than the standard K'-values of different kinds of ships in accordance with her Z test, her turning ability was found to be lower. The running distance of a turn in her 10$^{\circ}$ Z test was about 8.3 times her own length and was found not to be exceeded the standard maneuvering distance, therefore she was considered to have good maneuverabilities synthetically.