• 한국항행학회논문지
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• 제23권4호
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• pp.289-295
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• 2019

국제항로표지협회에서는 해양 분야에서 활용하는 백업항법시스템의 경우 항만 입출항시 10 m의 수평정확도를 보장하도록 요구하고 있다. 대표적인 해양분야의 백업항법시스템인 eLoran은 10 m 이내의 수평 정확도를 만족함이 증명되었지만, 수신환경에 따라 항법성능이 저하되기도 한다. 특히 수신 안테나 주변의 잡음 및 멀티패스 등으로 인한 요인으로 인해 특정 상황에서는 항법 자체가 불가능해지기도 한다. 본 논문에서는 이러한 환경에서 항만입출항 조건의 수평정확도 요구성능을 만족하기 위하여 UAV(unmanned aerial vehicles)를 활용한 선박의 백업항법시스템을 설계하였다. eLoran 신호 수신에 영향을 주는 주변 환경의 영향을 감소시키기 위하여 UAV에 카메라, IMU센서, eLoran 안테나 및 수신기를 장착하였으며, 선박의 안테나보다 높은 곳에서 카메라를 이용하여 랜드마크를 추적하고 일정 범위 내에서 eLoran 신호 수신과 위치 및 자세를 제어하도록 설계하였다. 선박에서는 UAV로부터 수신한 영상 및 자세 정보와 eLoran 신호를 이용한 선박기반 측위결과를 이용해 항만 입출항 시 수평정확도 요구성능을 만족할 수 있다.

• 대한조선학회논문집
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• 제42권6호
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• pp.666-672
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• 2005

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MO-ARS) might be one candidate of several systems against the ship's rolling. In this paper, three types of MD-ARS, two passive and one active devices, are developed for small ships. After they are installed on the cabin of the small leisure boat, respectively, a series of performance test is conducted before and after operating them. Through the test, it is confirmed that the roll responses of the ship are pretty well reduced by the MO-ARS.

• 한국해양공학회지
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• 제32권2호
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• pp.138-142
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• 2018

The marine industry is rapidly developing as a result of the increase in various needs in the marine environment. In addition, accidents involving ship fires and explosions and the resulting casualties are increasing. Generally, manpower and safety problems exist in fire fighting. A fire fighter in the form of an autonomous surface robot would be ideal for marine fire safety, because it has no manpower and safety problems. Therefore, an autonomous surface robot with the abilities of fire recognition and tracking, nozzle selection, position and attitude control, and fire fighting was developed and is discussed in this paper. The test and evaluation results of this robot showed the possibility of real-size applications and the need for additional studies.

• 한국항해항만학회지
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• 제33권8호
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• pp.531-537
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• 2009

항만국 통제 점검(Port State Control Inspection)은 해양 선박사고의 대부분이 선박 자체의 결함 보다는 인적 과실에 의하여 발생되고 있다는 사실을 인지하고 선박을 운항하고 있는 선원의 자격 검증과 교육훈련 부문의 점검을 강화하고 있다. 이에 따라 날로 강화되고 있는 국제 협약과 국제 법규를 충족시키기 위한 선원의 재교육훈련을 어떻게 효과적이고 효율적으로 시행하느냐가 해운기업에 있어서 풀어나가야 할 숙제라 할 수 있다. 이에 본 연구에서는 국내 S사의 피 교육자들을 대상으로 설문조사를 실시하고 연령, 학력, 근무연수, 직위 등을 기준으로 응답자를 분류하여 교육 훈련의 목적 및 필요성, 자기 동기부여, 교육효과 및 성과, 교육훈련의 만족도 등 4개 항목에 대한 인식의 차이를 분석하고 교육의 효과를 높일 수 있는 교육 방안 수립을 위한 시사점을 도출하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.201-201
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• 2000

Recently in the design of fuel tanks(launch vehicle, ship, automobile) which transport a large amount of liquid in the cargo holds, the structural damage due to liquid-sloshing becomes an important problem. The impact pressure from sloshing is most violent when the liquid motion of a partially filled tank is in resonance with the motion of a system. In this paper, the sloshing natural periods in liquid tanks are estimated for partially filled tanks with various geometries. In addition to, controlled for a launch vehicle with liquid sloshing effect by PD controller and sloshing filter The PD gain and sloshing filter parameter arc determined by optimal algorithm.

• 한국항공우주학회지
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• 제43권2호
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• pp.172-178
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• 2015

제어 모멘트 자이로(control moment gyroscope, CMG)는 고토크 발생 장치로서 인공위성 뿐만 아니라 항공, 선박, 자동차, 로봇 등의 다양한 산업분야의 자세안정화와 기동 시스템에 적용될 수 있다. 본 논문은 여러 산업분야에서 적용할 수 있는 100Nm급 CMG 개발 전반에 대한 내용을 다룬다. 이를 위해서 CMG 시스템레벨 요구사항 분석, 모터 서브시스템 설계/제작/조립, 시험장치 구성, 성능시험 및 평가에 대한 개발과정과 결과를 제시한다. 스핀모터와 김벌모터를 설계조건에서 구동하여 CMG의 토크출력이 120Nm 이상 생성됨을 성능시험을 통해 확인한다.

• 대한가정학회지
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• 제27권4호
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• pp.123-137
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• 1989

The purpose of this study is to examine parental attitudes perceived by juvenile delinquents and to provide the basic material on the problem of juvenile delinquency. For this purpose, this study examines 1) the relation-ship between the juvenile delinquents' social demographic characteristics and the juvenile delinquents' view of parental attitudes 2) the correlation between the juvenile delinquents' social demographic characteristics and the content and the motive of delinquency, 3) the content and the motive of delinquency in accordance with the juvenile delinquents' view of parental attitudes. For the subject of this study, 318 juvenile delinquents who were in the custody of the institution in An-Yang were selected, and questionnaire sheets were used. Of 318 questionnaire sheets, 221 sheets were analyzed by statistical methods, and the data were analyzed by frequency, percentage, average, t-test, x-test, and F-test; 1. There is a significant difference in the juvenile delinquents' view of their fathers in accordance with their fathers' age. Namely, the younger the father is, the more the juvenile delinquent wants his father to be less negative. There is a significant difference in the juvenile delinquents' view of their mothers according to the existence of step-sibling. Juveniles with step-siblings deny their mothers' inconsistent attitude more than the juveniles without a step-sibling. 2. The social demographic characteristics influencing the content of juvenile delinquency are juvenile's age, the degree of education, the father's age, the style of possessing house and the region of a dwelling. The motive of delinquency show a significant difference according to the juvenile's age. 3. According to the results of studying the correlation between the view of parental attitudes and the content and the motive of delinquency, there is a significant difference in the father's protective attitude, and the content of delinquency as well as in the mother's positive denial, her rigid control, her inconsistent attitude and the content of delinquency. The subordinate domains are opposite to the traditional conception that the father is stern and the mother is peronssive. Today our society encourages the parents' equal and democratic attitude toward their children and the juvenile's view of parental attitudes is discordant with the reality. The juvenile delinquents' view of parental attitudes reflects the equalitariansim of the contemporary society but is influenced by the traditional view of the parents.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.691-698
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• 2020

In this study, the effects of hydrodynamic interceptors on a high-speed vessel were investigated to identify the operating principle based on experiments. Model tests were performed using a high-speed towing carriage. The resistance, trim and rise of Center of Gravity (CG) of the high-speed vessel were measured for various ship speeds and interceptor heights. As the interceptor height increased, the trim and rise of CG were reduced. In order to quantitatively analyze these phenomena, the pressure at the stern bottom was measured using tactile sensors. The reliability of the measured results from the tactile sensors was verified through repeat tests. The pressure on the stern bottom increased in proportion to the interceptor height, as the interceptor partially blocked the flow there. Then, the trim was reduced. However, as the ship speed increases, the pressure at the location close to the interceptor decreases when the interceptor height is small, leading to increased trim. Therefore, the interceptor height for running attitude control should be carefully determined considering multiple factors in the operating condition of the high-speed planing hull.

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1253-1267
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• 2005

Misalignment can be an important problem in the integration of GPS/INS. Observability analysis of the alignment errors in the integration of low-grade inertial sensors and multi-antenna GPS is presented in this paper. A control-theoretic approach is adopted to study the observability of time-varying error dynamics models. The relationship between vehicle motions and the observability of the errors in the lever arm and relative attitude between GPS antenna array and IMU is given. It is shown that alignment errors can be made observable through maneuvering. The change of acceleration makes the components of the relative attitude error that are orthogonal to the direction of the acceleration change observable. The change of angular velocity makes the components of the lever arm error that are orthogonal to the direction of the angular velocity observable. The motion of constant angular velocity has no influence on the estimation of the lever arm.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 춘계학술대회 학술발표 논문집
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• pp.149-152
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• 2001

선박이 해상에서 운항시, 선체는 파도에 의해 심하게 동요되기 때문에 승선감과 안전성이 저하된다. 따라서 선박의 안전항해, 쾌적한 승선감, 구조적인 안전 보장을 위한 선체제어를 위한 필요성이 증대되어 왔다. 기존의 PID 제어기법 등은 정상편차가 적어 과도응답의 문제점 및 오차누적의 문제점이 있고, 퍼지제어 기법은 최적화가 어렵다는 단점을 가진다. 본 논문에서는 퍼지추론 기법을 이용한 선체자세 제어기법으로 운동체에 관한 전문가의 지식과 경험을 바탕으로 퍼지집합과 퍼지규칙을 설정하고 설계된 퍼지 추론을 통해 현재의 운동상황을 판단함으로써 효과적인 최적화와 자세계산을 수행할 수 있다. 본 논문에서는 퍼지추론을 이용한 자세제어 알고리즘을 제안하고 실시간 시뮬레이션을 통하여 시험한다.