• 대한조선학회논문집
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• 제44권6호
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• pp.572-578
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• 2007

A Rigid Inflatable Boat (RIB) is now widely used for commercial and military purpose. In this paper, it is supposed that seven-meter-class RIB be used as an unmanned target ship for naval training. In order to develop many tactical maneuvering patterns of a target ship, a simple horizontal maneuvering model of a RIB is needed. Therefore, models of speed and yaw rate are constructed as the first-order differential equations based on Lewandowski#s empirical formula for steady turning circle diameter of a conventional planning hull. Some parameters in the models are determined using the results of sea trial tests. Finally, proposed models are validated through the comparison of the simulation result with the sea trial result for a specific scenario. Even though a simple model does not represent the horizontal motion of a RIB precisely, however, it can be used enough to develop tactical trajectory patterns.

• 대한기계학회논문집A
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• 제20권8호
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• pp.2449-2457
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• 1996

This paper presents a design method for autopilot control system in course change to the specified direction based on a robust digital servo controlmelthod incorporating the concept of the annihilator polynormial. The mathematicalmodel of ship turning motion is very complex in the view of practical control because it has time varying parameters, nonlinear and dead time terms. To apply the digital servo control method based on computer control, the model is linearized at an equilibrium point and discretized with appropriate sampling time. The control algorithm was evaluated on the basis of computer simulation for a model ship and the practical experiment was carried out with an image processing method for measurement of ship position in a water tank. The results of overall experiments show that the proposed control method will be one of good way to keep a track plotted in the map.

• 한국항해항만학회지
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• 제36권8호
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• pp.613-618
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• 2012

부선이 선미 예인되는 상황에서의 예부선 통합시뮬레이션을 수행하기 위하여, 본 연구에서는 부선 단독 조종성능 추정을 위한 구속모형실험을 수행하였다. 구속모형실험결과로부터 부선 실선의 저항성능을 추정하였고, 도출된 유체력 미계수를 이용하여 선회시뮬레이션을 수행하였다. 부선의 선회시뮬레이션을 위해 부선에 작용하는 예인력의 힘과 방향을 단순히 모델링하고, 예인줄 방향각 변화에 따른 선회시뮬레이션 결과 비교와 실선시운전시험결과와의 선회직경 비교를 통하여 수학모델을 검증하였다. 그 결과 예인줄 방향각이 커질수록 선회직경이 작아지는 정성적인 경향을 확인하였고, 실선시운전결과와 비교 시 배수량 차이 등에 의하여 선회직경이 작게 추정되는 결과를 확인하였다.

• 한국정보통신학회논문지
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• 제14권11호
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• pp.2485-2490
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• 2010

본 논문에서는, 수면을 이루는 침실의 수면 환경 데이터를 채취하고 얻은 조건 데이터들과 수면 사이의 관계를 분석하였다. 이것을 기초로, 모의실험 모델을 추출하여 개인별 최적의 수면 환경을 제공하도록 한다. 시스템의 실험은 온/습도 센서와 조도 센서로 구성된 H-MOTE2420 센서를 이용하였다. 수면 중 뒤척임의 추출을 위하여 비디오에서 움직임을 추출하는 차영상 방법을 이용하였다. 또한, 수면에 영향을 끼칠만한 가중치의 정보로 피로한 정도, 음주의 정도, 공복의 정도 등의 정보를 입력 받는다. 실험 결과 최적의 수면환경을 추출할 수 있었다. 향후, 수면의 특수한 상황뿐만 아니라 식사나 출근과 같은 유기적인 생활환경의 한 부분에도 상황에 따른 적절한 실내 환경 변화를 제공해 주어서 좀더 쾌적한 일상생활을 영위할 수 있도록 도움을 주도록 개선하려 할 것이다.

• 한국컴퓨터정보학회논문지
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• 제16권1호
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• pp.47-52
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• 2011

본 논문은 수면을 이루는 침실의 수면 환경 데이터를 수집하고, 얻어진 조건 데이터들과 수면간의 관계를 분석한다. 이를 바탕으로 시뮬레이션 모델을 추출하여 개개인에 따른 최적의 수면 환경을 제공하도록 한다. 실험은 H-MOTE2420 센서의 온/습도 센서(SHT11)와 조도 센서(GL5507)를 이용하였다. 뒤척임 추출을 위하여 비디오에서 움직임을 추출하는 차영상 기법을 이용하였다. 또한, 수면에 영향을 미칠만한 가중치의 정보로 피로도, 음주도, 공복도 등의 정보를 입력 받는다. 실험 결과 최적의 수면 환경을 추출할 수 있었다. 향후에는, 수면의 특정 상황만 아니라 식사, 출근 등과 같은 유기적인 유비쿼터스 생활환경의 한 부분에도 상황에 따른 적절한 실내 환경 변화를 제공 해주어서 좀 더 쾌적한 일상생활을 영위할 수 있도록 도움을 주도록 개선하려 할 것이다.

• 수산해양기술연구
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• 제56권2호
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• pp.163-171
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• 2020

Engaged in trawling in limited fishing grounds with a number of fish schools could cause collisions between fishing vessels. Therefore, providing accurate maneuver information according to the situation could be regarded as essential for improving seafarers safety and fishing efficiency as well as safety of navigation. It is difficult to obtain all maneuver information through sea trial tests only, so a method through empirical formula is necessary. Since most empirical formulas are developed for merchant ship types, especially the characteristics of hull shape parameter like C_bB/L and dC_b/B etc. are clearly different between fishing vessels and merchant ships, this could occur estimation errors. Therefore, in this study, the authors have selected target fishing vessels and merchant ships and analyzed the characteristics of hull shape parameter according to the ship types. Based on this analysis, the empirical formula developed for the merchant ship type has applied to the target fishing vessels; it has verified through the turning motion simulation that the estimation error could be generated. In conclusion, it is necessary to include the characteristics of the hull shape parameter of fishing vessels in the empirical formula in order to apply the empirical formula has developed for merchant ship types to fishing vessel types.

• 한국해양공학회지
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• 제35권3호
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• pp.173-182
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• 2021

The maneuvering performance of a ship on the actual sea is very different from that in calm water due to wave-induced motion. Enhancement of a ship's maneuverability in waves at the design stage is an important way to ensure that the ship navigates safely. This paper focuses on the maneuvering prediction of a Russian trawler in wind and irregular waves. First, a unified seakeeping and maneuvering analysis of a Russian trawler is proposed. The hydrodynamic forces acting on the hull in calm water were estimated using empirical formulas based on a database containing information on several fishing vessels. A simulation of the standard maneuvering of the Russian trawler was conducted in calm water, which was checked using the International Maritime Organization (IMO) standards for ship maneuvering. Second, a unified model of seakeeping and maneuvering that considers the effect of wind and waves is proposed. The wave forces were estimated by a three-dimensional (3D) panel program (ANSYS-AQWA) and used as a database when simulating the ship maneuvering in wind and irregular waves. The wind forces and moments acting on the Russian trawler are estimated using empirical formulas based on a database of wind-tunnel test results. Third, standard maneuvering of a Russian trawler was conducted in various directions under wind and irregular wave conditions. Finally, the influence of wind and wave directions on the drifting distance and drifting angle of the ship as it turns in a circle was found. North wind has a dominant influence on the turning trajectory of the trawler.

• 대한조선학회논문집
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• 제59권6호
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• pp.423-431
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• 2022

In this paper, the results of Planar Motion Mechanism (PMM) test for a 1/15 scaled model of the MARIN Joubert BB2 submarine is dealt with to derive the maneuvering coefficients for surface condition. For the depth of surface navigation, the top of the sail was exposed 0.46 m above the water surface in the model scale, and it corresponds to 6.9 m in the full scale. The resistance and self-propulsion tests were conducted, and the model's self-propulsion point was obtained for 1.328 m/s, which corresponded to 10 knots in the full scale. The maneuvering tests were performed at the model's self-propulsion point, and the maneuvering coefficients were obtained. Based on the maneuvering coefficients, a turning simulation was performed for starboard 30 degree of stern fins. The straight-line stability and control effectiveness in the horizontal plane were analyzed using the maneuvering coefficients and compared with the appropriate range. For the analysis of the neutral fin angle of the X-type stern fin, the stern fin test with drift angles was carried out. As a result, the flow straightening effect at lower and upper parts of the stern fin was discussed.