• Proceedings of the KSME Conference
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• 2000.04a
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• pp.487-492
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• 2000

Yaw moment control algorithm for improving stability of a vehicle in cornering is presented in this paper. A change of the yaw moment according to an increment in brake ship at each wheel is examined and reflected in the control algorithm. This control algorithm computes the target yaw velocity as the vehicle motion desired by the driver for directional stability control in cornering and it makes the actual yaw velocity follow the target one. The yaw moment control was achieved by brake slip control and simple brake slip control logic was introduced in this paper.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.5 no.1
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• pp.46-52
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• 2002

A robust nonlinear observer, utilizing the sliding mode concept, is developed for the dynamic positioning of ships. The observer provides the estimates of linear velocities of the ship and bias from slowly varying environmental loads. It also filters out wave frequency motion to avoid wear of actuators and excessive fuel consumption. The main advantage of the proposed observer is in its robustness. Especially, the observer structure with a saturation function makes the proposed observer robust against neglected nonlinearties, disturbances and uncertainties. Since the mathematical model of DP ships is difficult to obtain and includes uncertainties and disturbances, it is very important for the observer to be robust. A nonlinear output feedback controller is derives based on the developed observer using the observer backstepping technique, and the global stability of the observer and control law is shown by Lyapunov stability theory.. A set of simulation was carried out to investigate the performance of the proposed observer for dynamic positioning of ships.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.245-251
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• 2005

Ship's auto pilot is must necessary the azimuth data, which is supported by a gyro, geomagnetism and GPS compass. The gyro compass is operation of stability & correct , therefore it is used by big size shipping because of high cost. The other side, medium and small size shipping are used the geomagnetism and GPS compass of low cost. This paper have studied that the two jobs are going on at the same time both of there's advantage. Which is asked the algorithm for stability azimuth data on reject methode the defect of respect with geomagnetism & GPS compass.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.14-21
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• 1994

The studios on the stability of damaged ships have been carried out continuously to prevent frequent damages or sinkings which cause large loss of life and fortunes. For dry cargo ships, continuing losses have resulted in new legislation of the probabilistic damage stability. IMO has developed requirements for the subdivison and damage stability of dry cargo ships based on probabilistic concepts. The calculation of the probabilistc damage stability is a complicated and iterative job hence development of computer programs is indispensable. In this research, programming of the probabilistic damage stability according to new requirements has been done and the results were compared with those carried out by the other foreign packages. New algorithm using a grid model in a transversal section was introduced to reduce efforts in preparing input data for damage scenarios and as a result, has brought significant improvement in efficiency and performance.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.1-8
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• 2023

In this study, the stability of fishing boat inducing the change of fishing lamp in accordance with the installation of induction lamp in comparison with metal halide lamp was investigated. Inclining test for 8.55 ton class of hair-tail angling fishing boat was performed in order to find a GM and light weight. A stability calculation of the target fishing boat on the basis of KST-SHIP program was evaluated. The stability of the fishing boat with a metal halide lamp such as induction lamp according to the result obtained by the inclining test is slightly different, and the stability is not so much affected. Due to the induction lamp installation, the wind area increased by about 3.178 m². Before installing the induction fishing lamp, G₀M was found to be 0.209 at full load departure and 0.296 at departure from fishing ground. After installing the induction lamp, the full load departure condition is 0.178 and the fishing ground departure condition is 0.260. The G₀M value before and after installation of the induction fishing lamp shows a difference of about 3% at the full load departure condition. The value of the critical angle of inclination definition showed a difference of about 16%. Despite these differences, it is lower than the regulations; it was confirmed that there will be no significant difference unless it is in an overloaded state.

• Journal of the Korean Institute of Navigation
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• v.11 no.1
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• pp.93-106
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• 1987

Nowadays natural resources on shore have been almost exhausted all over the world and mankind is beginning searching for unexploited resources on the bed of deep-sea floor. In exploring mineral resources and etc. in the ground of sea-bed, a sumbersible craft is one of the most important tools. These days, the stage of the technique of building and operating an exploring submersible craft is almost alike that of building and operating an airplane in the first years of the nineteen-twenties. At the present time, the problems arising in building and operating a submersible craft can be divided into four parts as follows; 1. How to build a hull that can bear high pressure under deep sea level. 2. How to decide the necessary facilities to be put on it. 3. How to decide the scope of stabilities and maneuvering characteristics of it. 4. On what sea conditions, the devices of launching and recovering it should be designed on the mother-ship. In this paper treating one of the third problems the author made a mathematic formula that can be useful in deciding the scope of dynamic course stability on the vertical plane and actually calculated the onset speed of pitch instability of an exploring craft. With the above mentioned calculations the author demonstrated that the value of $Z_g$ and the speed of a submerged craft are the most important factors in decideing the scope of dynamic stability on the vertical plane.

• Journal of the Korean Home Economics Association
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• v.23 no.4
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• pp.1-7
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• 1985

The aim of this study is to find out the relation-ship between personality and te factors for clothing selection. For the test, 396 high school girl students in Seoul were selected, respectively. The general personality test sheets by Kim Giseok and the questionnaire besed on Park Eunju's study on the factors for clothing selection were given to the sample group. RESULTS : 1. Behavior of clothing selection according to expression of individuality is sign ificantly correlated with ascendancy and sociability at the level of .001, and with emotional stability at .50. 2. Behavior of clothing selection according to utility is significantly correlated with resopnsibility and emotional stability at the level of .01. 3. Behavior of clothing selection according to economy is significantly correlated with ascendancy and self-confidence at the level of .01, and with responsibility and sociablity at .05. 4. Behavior of clothing selection according to modesty is significantly correlated with ascendancy and sociability at level of .001, and with self-confidence at .01. 5. Behavior of clothing selection according to conformity is significantly correlated with ascendancy, emothional stability, and self-confidence at the level of .001, and with sociability at .05.

• Journal of Ship and Ocean Technology
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• v.6 no.2
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• pp.12-22
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• 2002

Offshore pipelines play an important role in the transportation of gas, oil, water and oil products. It is common to have a group of pipelines in the oil and gas field. To reduce the installation cost and time, dual pipelines are designed. There are great advantages in the installation of dual pipelines over two separate single lines. It can greatly reduce the cost for trench, back-filling and installation. However the installation of dual pipelines often requires technical challenges. Pipelines should be placed to be stable against external loadings during installation and design life period. Dual pipelines in trench can reduce the influence of external forces. To investigate the flow patterns and forces as trench depth and slope changes, number of experiments are conducted with PIV(Particle Image Velocimetry) equipment in a Circulating Water Channel. Numerical approaches to simulate experimental conditions are also made to compare with experimental results. The velocity fields around dual pipelines in trench are investigated and analysed. Comparison of both results show similar patterns of flow around pipelines. It is proved that the trench depth contributes significantly on hydrodynamic stability. The trench slope also affects the pipeline stability. The results can be applied in the stability design of dual pipelines in trench section. The complex flow patterns can be effectively linked in the understanding of fluid motions around multi-circular bodies in trench.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.593-598
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• 2014

To solve the labor shortage of skilled workers, the ship building industry needs the automation and mechanization. Especially, compared with other process, handrail manufacturing process of ship building falls behind the automation. In this paper, we designed and implemented a flat-iron automation system using computer convergence technology that can be used in the production of handrails in shipbuilding. The system's machine part was designed by considering the efficiency, productivity, and stability of the cutting process, and checked the stability of the structure using CATIA and ANSYS. The system's control part was used the PCNC controller to provide openness and scalability. And the part was made for system control and monitoring the system through screen manipulation with touch-screen form. A flat-iron automatic system was developed by converging the mechanics, electronics and computer technology and it will contribute to improve the productivity of the industrial system.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.11
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• pp.503-510
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• 2014

With the development of electronic communication technology, the ship's navigational equipment is being digitized, and it has being studied touch-screen-based navigation user interface. However, due to the influence of environmental factors such as waves, it has a potential problem hazardous marine accident occurs due to incorrect operation, the systematic research in consideration of this be done do not. In this paper, we provide a user interface experimental model to verify the stability that takes into account the external environment of the touch-screen input on. Further, we simulated to verify that the interface of the touch screen, the effect of applying the input delay time and the size of the button is obtained through the experimental model proposed. It will be able to greatly contribute to studies of the interface robust touch screen user errors that can be analyzed by the experimental model is proposed to improve the ship, the overall system stability.