• Title/Summary/Keyword: Course-Keeping

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

  • Seo, Ju-Won;;;;Jeon, Myeong-Jun;Yun, Hyeon-Gyu;Kim, Yeon-Gyu
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.11a
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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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A Study on the Assessment for the Auto-pilot System of a Ship in Waves (파랑중 선박의 자동조타 시스템의 평가에 관한 연구)

  • S.K. Lee;K.W. Lee;T.K. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.35 no.1
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    • pp.40-45
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    • 1998
  • There are two kinds of methods in the analysis of ship motion in irregular waves. The one is the spectral method in which the ship motion is assessed with spectral of irregular waves times R.A.O. of a ship. The other is, so called, time domain analysis, in which the irregular waves are used directly in the equation of ship motion to calculate the responses. In this paper, both methods are applied for the calculation of course keeping motion of a ship in irregular waves with auto-pilot control. And, the differences and useful1ness of the two methods in the assessment of auto-pilot system are compared.

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

  • 정세모;김효중;노장주;이상집
    • Journal of the Korean Institute of Navigation
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    • v.8 no.1
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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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On the reading method of Korean old poetry in the digital age (디지털 시대 고전시가 읽기)

  • Yeom, Eun-yeol
    • Journal of Korean Classical Literature and Education
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    • no.16
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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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    • v.12 no.1
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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.

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

  • Kim, J.H.;Suh, G.S.;Chang, H.Y.;Chang, K.J.;Lee, K.H.;Song, C.Y.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.9 no.1
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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.

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 - (메뉴 엔지니어링, CMA분석방법에 의한 일식 메뉴 비교분석 - 특 1급 A호텔 레스토랑 사례 -)

  • Jeong, Woo-Seok;Byun, Kwang-In;Park, Sung-Su
    • Journal of the Korean Society of Food Culture
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    • v.23 no.5
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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.

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

  • Kim, Jung-Soon
    • The Journal of Korean Academic Society of Nursing Education
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    • v.6 no.2
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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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A Study on the Minimum Engine Propulsion Power Required for Safe Navigation of Small and Medium Ships (중소형 선박의 안전항해를 위한 주기관 최소출력에 관한 연구)

  • Kang, Suk-Young;Ahn, Young-Joong;Kim, Seung-Yeon;Lee, Yun-Sok
    • Journal of Navigation and Port Research
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    • v.42 no.6
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    • pp.415-420
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    • 2018
  • The Energy Efficiency Design Index (EEDI) introduced by the Marine Environment P rotection Committee(MEPC) in International Maritime Organization(IMO) has significantly assisted in regulating CO2 emissions. However, in adverse weather conditions, it can lead to accidents due to slow steaming of vessels and low engine propulsion power. In response to this issue, the MEPC presented guidelines for the minimum propulsion power of the main engine for maintaining the course of vessels in adverse weather conditions. However, the guidelines are only applicable for vessels with a deadweight of 20,000 tons, leaving out small and medium ships. This study evaluated vessels subject to the guidelines of minimum propulsion power and proposed revised guidelines. In addition, relevant cases of marine accidents were investigated with the aim of investigating the minimum propulsion power of main engine for medium and small ships not covered by the guidelines. In order to achieve this, engine propulsion power was analyzed according to the size of the affected vessels. The results obtained from this study could be used as a minimum power criterion that can be considered for ship building to reduce marine accidents in adverse weather for small and medium ships.

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

  • Sun woo Lee;Sang hyun Kim;Hye woo Kim;Hyung seok Yoon;Chang woo Song;Joo hyung Oh
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.4
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    • pp.348-357
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    • 2024
  • Maneuvering performance is crucial for fishing vessels, especially under operational conditions that involve frequent course changes and weight variations due to catch. Small vessel accidents account for approximately 60% of maritime incidents as of 2022, mainly attributed to collisions and stranding accidents due to insufficient maneuvering performance. Especially, accidents that occur on small vessels less than 10 tons account for about 65% of all accidents. The absence of international standards presents challenges in accurately evaluating the maneuvering performance of small vessels. In this study, a 4.99-ton small fishing vessel was selected as the target, and a 3d-cad model was created. The commercial numerical analysis program STAR-CCM+ was employed to establish a simulation environment for the vessel's maneuvring motion. Based on this standard loading conditions and weight distribution were considered, 10° / 10°, 20° / 20° zigzag tests and 35° turning test were conducted. The results revealed a tendency for decreased yaw and course-keeping performance and improved turning performance as the hull weight increased. However, in partial arrival and full load departure condition, the manoeuvering performance were relatively poor. Based on this, the need for evaluation of maneuvering and standardized criteria of maneuvering performance for safe navigation of small vessels is presented. Furthermore, it is expected that the evaluation results of maneuvering performance in this study can serve as fundamental data for establishing criteria for evaluating the maneuvering performance of small vessels.