• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.08a
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• pp.119-123
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• 2000

In this paper, authors introduce about Wide Range Vessel Traffic Service (VTS) system using Automatic Identification System (AIS). In order to develop the prototype of Wide Range VIS system, Korean satellite is used for data communication system for AIS. In this system, ship position obtained by using GPS is reported automatically to VTS center through Korean satellite. By using this system, VTS center can cover more wide area than the case using radar only. And the uncertainty of information is decrease. The results of test show the good possibility of VTS using satellite and AIS.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.2
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• pp.236-242
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• 2005

Dynamic Positioning(DP) system maintains ship's position (fixed location or predetermined track) exclusively by means of CPPs and thrusters. To generate the control input adequate to various situation an integrated controller for CPPs and thrusters is required. The integrated controller is composed of a thrust calculation algorithm and a thrust allocation algorithm. The thrust calculation algorithm generates thrusts in the surge direction and the sway direction from the desired forward and lateral speed and generates a moment about the yaw axis from desired heading angle. The thrust allocation algorithm allocates the generated thrusts and moment to each CPP and thruster. Computer simulations are executed to confirm the effectiveness of the suggested controller.

• Journal of Korean Port Research
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• v.8 no.1
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• pp.65-74
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• 1994

There are some turn maneuvers, such as hard Round Turn, Turning Short Round, Williamson Turn and Single Turn, of effectively returning a ship back close to the original track in case of emergency situations of man-overboard and intentional delay of port entrance time, and so forth. But the author developed the new turn maneuvers of Double 30 (woo) Turn originally by means of simulation experiments of Full-Mission Shiphandling Simulator. The conclusions of this study are as follows: 1) By comparison of existing Williamson Turn and Turning Short Round this Double 30(woo) Turn is all-weather multipurpose turn maneuvers in some respects, 2) According to simulation experiments this Double 30 (woo) Turn saved approximately 20-35% of total turning time to the original position and reduced maximum advances by 8-10% approximately in comparison to that of Williamson Turn, 3) Except for emergency men-overboard the Reverse Williamson Turn was proposed as a new reverse maneuver of returning a ship back to the original track.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.4
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• pp.412-418
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• 2014

In this paper, for better boarding performance and pleasant boarding sensitivity of the ship, comparison and analysis was performed of motion sickness questionnaire with MSI(Motion Sickness Incidence) calculation based on ship motion theory(Strip Method) due to sea condition, incident angle in main sail way, economic speed, and calculation position of the training ship Kaya of Pukyong National University. On theses works, the rougher sea conditions became, the higher total motion sickness rate was occurred. The weights of vertical acceleration and the rates of MSI were higher at the bridge and the accommodation, which were located farther from the center of gravity of the ship. And effects of the vertical acceleration of the ship were increased in rolling then in head sea. In comparison between motion sickness questionnaire with MSI calculation, when the vertical acceleration increased, the motion sickness rate increased. The location to increase vertical acceleration and the location to cause motion sickness were agreed.

• Journal of the Korean Institute of Navigation
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• v.7 no.2
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• pp.1-45
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• 1983

This paper concerns the applications of the Kalman filter to navigation and the develment of computer programs of the navigational calculations. Methods to apply the Kalman filter to celestial fix, fix by cross bearing and cocked hat are proposed, and numerical simulations under various noise conditiions are conducted. The accuracy of the optimal positions obtained by the Kalman filter is compared with that of the fixed positiions by radial error method. In the case of celestial fix, an algorithm to estimate the optimal positions by using the linear Kalman filter is presented. The optimal positions by the Kalman filter are compared with the running fixes and with the most probable positions obtained from a single line of position. It is confirmed that the resutls of the proposed method are more accurate than the others. In practical piloting, bearings are generally measured intermittently and the measurement process is nonlinear. It is, therefore, difficult for us to apply the Kalman filter to fix by cross bearing. In order to be used in such an unfavorable case, the extended Kalman filter is revised and the aplicability of the revised extended Kalman filter is checked by numerical simulation under various noise conditions. In a cocked hat, an inside or outside fix is dependent only upon azimuth spread, if the error of each line of position is assumed to be equal both in magnitude and sign. A new technique of selecting a ship's position between an inside fix and an outside fix in a cocked hat by using fix determinant derived from the equation of three lines of position is also presented. The relations among the optimal position by Kalman filter, incentre (or excentre) and random error centtre of the cocked hat are discussed theoretically and the accuracy of the optimal position is compared with that of the others by numerical simulation.

• Journal of the Korean earth science society
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• v.39 no.3
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• pp.241-249
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• 2018

As the international trade increases, vessel traffics around the Korean Peninsula are also increasing. Maritime accidents hence take place more frequently in the southern coast of Korea where many big and small ports are located. Accidents involving ship collision and sinking result in a substantial human and material damage as well as the marine environmental pollution. Therefore, it is necessary to locate the ships quickly when such accidents occur. In this study, we suggest a new ship detection index by comparing and analyzing the reflectivity of each channel of the Korea MultiPurpose SATellite-2 (KOMPSAT-2) images of the area around the Gwangyang Bay. A threshold value of 0.1 is set based on a histogram analysis, and all vessels are detected when compared with RGB composite images. After selecting a relatively large ship as a representative sample, the distribution of spatial reflectivity around the ship is studied. Uniform shadows are detected on the northwest side of the vessel. This indicates that the sun is in the southeast, the azimuth of the actual satellite image is $144.80^{\circ}$, and the azimuth angle of the sun can be estimated using the shadow position. The reflectivity of the shadows is 0.005 lower than the surrounding sea and ship. The shadow height varies with the position of the bow and the stern, perhaps due to the relative heights of the ship deck and the structure. The results of this study can help search technology for missing vessels using optical satellite images in the event of a marine accident around the Korean Peninsula.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.270-276
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• 2007

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.209-212
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• 1987

This paper presents a control scheme to stabilize a two-axes microwave antenna system which is located on a ship and is subject to roll, pitch and yaw(RPY) motions. The scheme first computes the compensated angular positions of the antenna for RPY disturbances through coordinate transformations, and then use a servo con roller of PID type for each axis to track the compensated position command with a good transient behavior.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.75-77
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• 2020

There was an outbreak of COVID-19 on the Diamond Princess cruise ship. Distinguishing close contacts is the important problem to be addressed. Close contacts mean people who stays with the patients of disease like COVID-19 over a period of time. The passenger position on board can be obtained by indoor positioning technology. The feature of close contacts is similar location with COVID-19 patients. Therefore, this paper proposed the idea of distinguishing close contacts on board based on DBSCAN algorithm.

• Journal of Ship and Ocean Technology
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• v.11 no.2
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• pp.1-9
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• 2007

This paper describes the design and development of a hovering AUV constructed at Cheju National University and analyses the dynamic performance of the vehicle using simulation programs. The main purpose of this AUV is to carry out fundamental tests in its station keeping, attitude control, and desired position tracking. Its configuration is similar to the general ROV appearance for underwater works and its dimensions are 0.75m*0.5m*0.5m. It has 4 thrusters of 450 watts for longitudinal/lateral/vertical propulsion and is equipped with a pressure sensor for measuring water depth and a magnetic compass for measuring heading angle. The navigation of the vehicle is controlled by an on-board Pentium III-class computer, which runs with the help of the Windows XP operating system. These give us an appropriate environment for developing various algorithms needed for developing and advancing Hovering AUV.