• 제목/요약/키워드: Course-keeping

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다방향 규칙파 중 선체, 타, 추진기에 작용하는 유체력 추정을 위한 실험적 연구

  • 서주원;응웬반민;응웬티당디엡;마이티로안;전명준;윤현규;김연규
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2018년도 추계학술대회
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    • pp.4-6
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    • 2018
  • Traditional methods of research on ship maneuvering performance were estimated in calm water. Ship maneuverability in waves is of vital importance for navigation safety of a ship (ITTC, 2008). The accurate estimation of force and moment acting on the ship and rudder behind propeller are necessary because the rudder, propeller and hull interaction is of key importance. In addition, course-keeping ability and maneuvering performance of a ship can be significantly affected by the presence of wave. In this study, the model test is performed in the regular wave in the square wave tank in Changwon National University and the hydrodynamic force acting on the ship hull and rudder behind the propeller in various wave directions is investigated. The effect of wavelength and wave direction on hydrodynamic force acting on ship and rudder behind propeller in regular waves is discussed.

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파랑중 선박의 자동조타 시스템의 평가에 관한 연구 (A Study on the Assessment for the Auto-pilot System of a Ship in Waves)

  • 이승건;이경우;김태경
    • 대한조선학회논문집
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    • 제35권1호
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    • pp.40-45
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    • 1998
  • 불규칙파중의 선박의 운동을 해석하는 방법으로 주파수 영역해석법과 시영역해석법이 있다. 주파수영역해석법은 스펙트럴해석기법에 의해 불규칙파중 선박의 운동특성을 구하는 방법이고, 시영역해석법은 불규칙파를 생성하여 이 파를 실제의 입력으로 하여 선박의 운동을 직접 계산하는 방법이다. 보통 취급이 간편한 주파수 영역해석법이 선박의 자동조타 시스템 평가에 자주 사용되고 있으나, 본 연구에서는 주파수 영역해석법과 시영역해석법에 의한 불규칙파중의 선박의 보침운동 및 자동조타 시스템 평가를 수행하고 두 방법을 비교 검토하였다.

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한국해기사의 교육개발에 관한 연구 (한국해양대학 승선학과교육의 발전과제) (Some Suggestions for the Development of the Nautical Education in Korea Maritime University)

  • 정세모;김효중;노장주;이상집
    • 한국항해학회지
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    • 제8권1호
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    • pp.71-102
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    • 1984
  • In Korea, the importance of keeping the see transportation facilities and well-trained maritime officers cannot be overemphasized, because of her geographical location and the national security in terms of both political and economical situations. In this paper, some points are suggested for the development of the nautical education in Korea Maritime University: (1) the strict regimental training should be kept as a vital important part of students life and its program should be designed to provide students with leadership training and experience, and to develope in the qualities of responsibilities for good citizenship and self-discipline to overcome hardwork for careers as leaders in Korea maritime industry. And therefore the dormitory and training vessel as essential parts of the educational facilities should be improved both in quality and quantity, (2) the undergraduate course should be extended to more than 5 years so that accredited baccalaureate curriculum and licensing professional education might be well conducted to meet the requirements to cope with the international competition in the facet of seafarers quality, (3) more enlarging the opportunities of incentive payments for students is required so that better qualified applicants can be admitted, (4) finally, a conjugal maritime officer service system should be put into practice in the foresseable furture so that seafarers might live normal family lives while staying at sea.

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디지털 시대 고전시가 읽기 (On the reading method of Korean old poetry in the digital age)

  • 염은열
    • 고전문학과교육
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    • 제16호
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    • pp.65-90
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    • 2008
  • This study is on the reading method of Korean old poetry in the digital age. Now days, we are living in digital media. The method of getting, organizing, and producing information is changed a lot. So for keeping pace with this change, we should reflect our teaching method. Of course, the purpose of our reflection is not to follow digital media's method and change or alter existing reading or teaching method, but it is to identify proper own reading strategy of old poetry and adjust existing method for our student who are skilled with digital media. We propose three kinds of method for student readers in school. These are 1) starting like a newspaper reader, 2) getting context (reading, making hyperlink), and 3) figuring as an architect (reading as space or scenery creator). In addition, we think about recent tendency that Korean old poetry is de-constructed and re-constructed as digital contents in digital space. We call it digitalizing of old poetry. The experiencing old poetry as a digital contents is different from reading old poetry, so we cannot alter old poetry reading experience into experience of digital contents. In conclusion, digitalizing contents should be used restrictively to fertilize reading experience of original old poetry.

Experimental and numerical study of autopilot using Extended Kalman Filter trained neural networks for surface vessels

  • Wang, Yuanyuan;Chai, Shuhong;Nguyen, Hung Duc
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.314-324
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    • 2020
  • Due to the nonlinearity and environmental uncertainties, the design of the ship's steering controller is a long-term challenge. The purpose of this study is to design an intelligent autopilot based on Extended Kalman Filter (EKF) trained Radial Basis Function Neural Network (RBFNN) control algorithm. The newly developed free running model scaled surface vessel was employed to execute the motion control experiments. After describing the design of the EKF trained RBFNN autopilot, the performances of the proposed control system were investigated by conducting experiments using the physical model on lake and simulations using the corresponding mathematical model. The results demonstrate that the developed control system is feasible to be used for the ship's motion control in the presences of environmental disturbances. Moreover, in comparison with the Back-Propagation (BP) neural networks and Proportional-Derivative (PD) based control methods, the EKF RBFNN based control method shows better performance regarding course keeping and trajectory tracking.

베트남 호치민에서의 셀레늄상황과 셀레늄영지 버섯의 시범재배 과정과 성과분석 (An Analysis of the Demonstrational Cultivation Process and Effect of Selenium Supplemented Phellinus. linteus and Ganoderma. lucidum)

  • 김종혁;서규선;장현유;장광진;이관호;송천영
    • 현장농수산연구지
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    • 제9권1호
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    • pp.105-117
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    • 2007
  • This study was carried to analyze the demonstrational cultivation process of selenium supplemented P. linteus and G. lucidum from 2005 to 2006 and ifs effect at Hochimin Agricultural Technology College(HATC) in Vietnam, according to the mutual contract between the Yunjung-nongwon, a fanning company in Korea and HATC. As a result of the demonstrational cultivation of selenium supplemented P. linteus and G. lucidum, the external aspect, such as size, thickness and color of the P. linteus and G. lucidum were very much high qualified comparing to the same strain P. linteus and G. lucidum generally cultivated in Korea. The major contribution factors to this high qualified mushroom product could be drawn as followings; keeping growing condition of the mushroom with precise data collection of Vietnam climate and weather, involvement of the various professors of Korea National Agricultural College(KNAC), maintenance of bio-technical security through the strain cultivation on the oak log in Korea, the Yunjung-nongwon manager's endeavor being consulted by the various professors of KNAC even to be a student of the agricultural chief executive officer(CEO) training course in KNAC and the HATC's constant cooperation to the mushroom demonstrational cultivation instead of the orchid which was originally contracted item.

메뉴 엔지니어링, CMA분석방법에 의한 일식 메뉴 비교분석 - 특 1급 A호텔 레스토랑 사례 - (Analysis of the Menu from a Japanese Restaurant Using Menu Engineering and Cost/Margin Analysis - A Case of a Restaurant at a First Class (A) Hotel -)

  • 정우석;변광인;박성수
    • 한국식생활문화학회지
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    • 제23권5호
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    • pp.595-604
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    • 2008
  • This study was conducted to evaluate the menu of a Japanese restaurant in a first class tourism hotel. The calculations used for the menu analysis were conducted using MS Excel 2003. Several previous studies have been conducted to analyze menus. For example, Pavesic used of the weighted contribution margins (WCM) and potential food cost (PFC%) to evaluate menus, while Kasavana & Smith used the mix margin (MM%) and unit contribution margin (CM) to evaluate menus. The menu engineering method focused on the customer's viewpoints, while the Cost/Margin analysis method considered the manager's viewpoints. The menus that need continuous keeping Kasavana & Smith (Star) and Pavesic (Standard) included 'Assorted sashimi with side dishes (big), 'Lunch box special', 'Tempura course', 'Broiled Spanish mackerel and side dishes', 'Shrimp tempura', 'Special sushi', 'Seafood Udong', 'Buckwheat noodles'. The results of this study should increase customer satisfaction and profits at the Japanese Restaurant.

장기이식 전문간호사를 위한 교육과정 연구 (A Model Curriculum Development for Clinical Nurse Specialist Training Program in Organ Transplant)

  • 김정순
    • 한국간호교육학회지
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    • 제6권2호
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    • pp.171-185
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    • 2000
  • The twenty-first century may be said to be entering into a specialized qualification age to meet the needs of new technical innovations such as environmental changes, demographical changes, changes in the constitution of diseases, changes in the needs of the national health, reforms of information and knowledge, etc., which requires the provision of competitive services that can fulfill the high level needs of consumers. In consequence, it is needed to apply a practical nursing model that can serve as a guide for healthy society and to secure the sphere that can affect nursing policy-making by keeping pace with the changing environment. Furthermore, it is also urgent to expand more the activity sphere of nurse specialists with authority and autonomy, establish their legal foundation, establish a qualification accreditation system for nurse specialists, and develop educational programs. In Korea, the law relative to organ transplant past the national assembly on February 9, 2000, legally acknowledged brain death, which indicated to us the emergence of an age of organ transplant. Therefore, it necessitates to find out those of brain death from whom organ transplant is feasible in clinical practices, with their families' consent link to those terminal organ failure patients who are in need of an organ, and mediate both parties so that smooth transplant can be accomplished. A series of these complicated procedures require systematically trained specialists with high level techniques of organic management. With this in mind, this study was conducted on 69 clinical nurse specialists for organ transplant, accredited by the hospital, who are in active service in clinical practices. The resultant findings were revealed, as follows: 1. The qualifications of clinical nurse specialists for organ transplant should be accredited by Ministry of Health and Welfare or Korea Nurses Association. 2. The validity of qualifications should be for three years, and their renewal should be based on marks of a supplemental training or an education course for more than 12 hours a year. 3. The qualification of the clinical nurse specialist necessitates theoretical lectures and practices on those nurses who have had clinical experience in the pertinent field. 4. The course of training is required to be one year in the length of training and take more than 20 credits (320 hours) and 5 credits (240 hours).

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중소형 선박의 안전항해를 위한 주기관 최소출력에 관한 연구 (A Study on the Minimum Engine Propulsion Power Required for Safe Navigation of Small and Medium Ships)

  • 강석용;안영중;김승연;이윤석
    • 한국항해항만학회지
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    • 제42권6호
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    • pp.415-420
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    • 2018
  • 국제해사기구의 해양환경안전위원회에 의해 도입된 에너지효율설계지수는 이산화탄소 배출량 규제를 위해 필요하나, 선박의 감속운항과 주기관 출력 저하로 황천항해 시 사고로 이어질 수 있다. 이에 해양환경안전위원회는 황천항해 시 선박의 침로유지를 위한 주기관 최소출력에 대한 지침을 제시하였으나, 이는 재화중량톤수 20,000톤 이상 선박에 대한 것으로 중소형 선박에 대한 기준은 부재하다. 본 연구는 최소출력에 대한 지침을 근거로 지침 적용대상인 선박을 평가하고, 수정된 지침을 제안하였다. 또한 지침 미적용 대상인 재화중량톤수 20,000톤 미만의 중소형 선박들에 대한 주기관 최소출력 제시를 목적으로 관련 해양사고 사례들을 조사하고, 선박의 크기에 따른 주기관 출력을 분석하여 중소형 선박에 적용될 수 있는 주기관 최소출력 기준을 제시하였다. 연구의 결과는 악천후 시 중소형 선박들의 해양사고 감소를 위해 선박 건조에 고려될 수 있는 최소출력 기준으로 이용될 수 있을 것이다.

CFD 시뮬레이션 기반 소형 어선의 표준재화상태에 따른 조종성능 평가 (Evaluation of Maneuverability of Small Fishing Vessels Based on CFD Simulation under Standard Loading Condition)

  • 이선우;김상현;김혜우;윤형석;송창우;오주형
    • 해양환경안전학회지
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    • 제30권4호
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    • pp.348-357
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    • 2024
  • 상선에 비해 잦은 변침을 하고 어획물로 인한 중량 및 무게중심의 변화와 같은 다양한 운항조건을 가진 어선의 경우, 조종성능은 선박 운항 시에 매우 중요한 역할을 한다. 소형 어선의 사고는 2022년 기준 전체 해상 사고의 약 60%를 차지하며, 이는 부족한 조종성능으로 인한 충돌과 좌초 사고가 주요 원인이다. 특히 10톤 미만의 소형선박에서 발생한 사고는 전체 사고의 약 65%를 차지하는데, 소형 어선의 조종성능 관련 기준이 부재하여 이를 정확히 평가하기엔 어려움이 있다. 이에 본 연구에서는 4.99톤급 소형 어선을 대상선으로 선정하여 3D-CAD로 모델링 한 후, 상용 수치해석 프로그램인 STAR-CCM+를 활용하여 선박의 조종운동 시뮬레이션 환경을 구축하였다. 이를 바탕으로 다양한 표준재화상태와 무게중심을 고려하여 10° / 10° 및 20° / 20° zigzag test와 35° turning test를 수행하였고, 선체 중량이 증가함에 따라 변침성능이 감소하고 선회성능이 향상되는 경향을 분석하였다. 그 중, 만재출항과 부분만재입항 상태에서는 상대적으로 선회성능이 부족한 결과를 확인하였다. 이를 바탕으로 소형선박의 안전한 운항을 위한 표준재화상태와 무게중심을 고려한 조종성능의 평가 및 그에 상응하는 표준화된 조종성능 평가 기준의 필요성을 제시하였다. 또한, 본 연구의 조종성능 평가 결과가 소형선박의 조종성능 평가 기준 선정을 위한 기초자료로 활용될 수 있을 것으로 기대된다.