• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.462-468
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• 2010

A new course keeping controller for RIB(Rigid Inflatable Boat)-type USV(Unmanned Surface Vehicle) is developed using pilot's steering pattern. A pilot's simple steering pattern is found out from various course change tests. It is used to course keeping algorithm, suitable for large course change more than 60 degrees. To validate the course keeping controller, sea trial tests are conducted. From sea trial test, new course keeping controller shows good performance with less overshoot, maximum roll angle less than $20^{\circ}$, which makes it possible that fast course changes without slip motion of USV.

• Journal of Navigation and Port Research
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• v.27 no.6
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• pp.631-638
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• 2003

Yaw-checking and course-keeping ability in IMO's ship manoeuvrability standards are reviewed from the viewpoint of safe navigation. Three kinds of virtual series-ships, which have different course instability, are taken as test models. The numerical simulation on Z-test is carried out in order to examine the correlation between known manoeuvrability in spiral characteristics and various kinds of overshoot angle. Then simulator experiments are executed with series-ships in a curved, narrow waterway by six operators(five active pilots and one ex-captain) in order to examine the correlation between known manoeuvrability and degree of manoeuvring difficulty. IMC criteria for yaw-checking and course-keeping ability are discussed and revised criteria are proposed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.585-598
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• 2021

The course-keeping stability of a high speed planing boat should be considered at the design stage for its safe operations. The shape of waterjet intake plane is one of important design parameters of a waterjet propelled planing boat. That has significant influences on the stern flow patterns and pressure distributions. In this study, the effects of the waterjet intake shapes of planing boats on the course-keeping stabilities are investigated. Two kinds of designed planing boats have the same dimensions, but there are differences in waterjet intake plane shapes. Captive and free-running model tests, Computational Fluid Dynamics (CFD) analyses are carried out in order to estimate their hydrodynamic performances including course-keeping stabilities. The results show that the flat and wide waterjet intake plane of the initially designed boat makes the course-keeping stability worse. The waterjet intake shape is redesigned to improve the course-keeping stability. The improved performances are confirmed by free-running model tests and full-scale trials.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.141-148
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• 2003

Yaw-checking and course-keeping ability in IMO's ship manoeuvrability standards is reviewed from the viewpoint cf sole navigation Three kinds of virtual series-ships, which have different course instability, are taken as test models. The numerical simulation on Z-test is carried out in order to examine the correlation between known manoeuvrability in spiral characteristics and various kinds of overshoot angle. Then simulator experiments are executed with series-ships in a curoed, narrow waterway by six operators(five active pilots and one ex-captain) in order to examine the correlation between known manoeuvrability and degree of manoeuvring difficulty. IMO criteria for yaw-checking and course-keeping ability are discussed and revised criteria are proposed.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.54-60
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• 1998

Generally, spiral test has been used for evaluating course-keeping quality of a ship. But, there are many difficult problems in performing spiral test and reversed spiral test. Therefore, we propose zig-zag test instead of spiral test for evaluating curse-keeping quality of a ship. In this paper, K-T maneuvering response model is applied to the spiral curves which are systematically produced to calculate Zig-zag maneuver. Then, 1st overshoot angle and 2nd overshoot angle are plotted. And the relations between overshoot angles and band widths of spiral curve are discussed.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.3-10
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• 2002

Yaw-checking and course-keeping ability in IMO's ship manoeuvrability standards is reviewed from the viewpoint of safe operation. Three types of assumed series-ships, which have systematically different instability on course, are taken as tested models. The numerical simulation on Z-test is carried out in order to examine the correlation between known manoeuvrability and various kinds of overshoot angle. Then simulator experiments are executed with series-ships in situation of curved, narrow of waterway by five pilots in order to examine the correlation between known manoeuvrability and degree of manoeuvring difficulty. Three kinds of IMO's criterion concerning yaw-checking and course-keeping ability are discussed and new criteria are proposed.

• Journal of Ocean Engineering and Technology
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• v.13 no.1 s.31
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• pp.18-22
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• 1999

One of the problem areas in designing a barge is its resistance and corese stability when it is towed by a tugboat. In this paper, as a part of design of a incinerating vessel, the results of some experimental studies on the effect of various kinds of anti-yawing skegs to the course keeping stability and on the additional resistance caused by them were summarized.

• Journal of Ship and Ocean Technology
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• v.6 no.3
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• pp.26-36
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• 2002

Yaw-checking and course-keeping ability in IMO's ship rnanoeuvrability standards is reviewed from the viewpoint of safe navigation. Three kinds of virtual series-ships, which have different course instability, are taken as test models. The numerical simulation on Z-test is carried out in order to examine the correlation between known manoeuvrability in spiral characteristics and various kinds of overshoot angle. Then simulator experiments are executed with series-ships in a curved, narrow waterway by five pilots in order to examine the correlation between known manoeuvrability and degree of manoeuvring difficulty. IMO criteria for yaw-checking and course-keeping ability are discussed and new criteria are proposed.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.95-99
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• 1997

In these days, the pollution of marine environment near island at Korean coastal zone caused by the trash human waste and livestocks excreata become intensified. One of the most economic and efficient way to prevent this pollution problem is to set up island circulating incineration system. In this paper, the result of feasibility study on the application of turtle boat hull form to the incinerating vessel has been summarized especially for the resistance and course keeping point of view.

• Journal of Ocean Engineering and Technology
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• v.25 no.5
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• pp.27-32
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• 2011

Recently, a ship-shaped barge has been developed to improve the resistance performance, as well as course-keeping capability. However, the stern of the barge is still similar to a box shape, and the vortex generated at the side of the barge creates drag and yaw instability. In order to solve this problem, stern skegs are normally used. The present paper deals with the correlation between the size of the stern skegs and the barge dimensions and hull coefficient. A stern skeg was designed to prevent yaw instability and minimize any additional resistance. The resistance test and course keeping test were performed in the towing tank at Pusan National University. To determine the correlation parameters between the designed stern skeg size and barge dimensions, a parametric study was also performed. Based on the experimental data from five barges, the optimum skeg dimensions were successfully derived. It is expected that the validation of the present study will be carried out by further experiments and computational comparisons in the near future.