• 제목/요약/키워드: Small boat

검색결과 209건 처리시간 0.033초

선형설계를 통한 G/T 29톤급 근해채낚기 어선의 저항성능 개선 (Improvement of the Resistance Performance for a G/T 29ton Class Coastal Angling Fishing Boat based on Hull-form Design)

  • 하윤진;이영길;이승희;김상현;유진원;백영수;배동균
    • 대한조선학회논문집
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    • 제51권6호
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    • pp.521-529
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    • 2014
  • In this study, numerical simulations and model tests are performed for the hull-form development of a G/T 29ton class coastal angling fishing boat. The numerical simulations are mainly used for the design of bow hull-form and the resistance performance is improved by the adoption of high bulbous bow. And, the resistance performances of the existing boat and the designed boat are verified by the model tests. The results of the experiments and calculations show that the effective power of the designed boat is 13.6% less than that of the existing boat at design speed. Therefore, the results of this research could be used as one of the fundamental data for the design of G/T 29ton class coastal angling fishing boat.

Electrical Characteristics of Organic Light-emitting Diodes Fabricated by Varying a Hole-size in Evaporation Boat

  • Kim, Weon-Jong;Park, Young-Ha;Cho, Kyung-Soon;Hong, Jin-Woong;Shin, Jong-Yeol;Kim, Tae-Wan
    • Transactions on Electrical and Electronic Materials
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    • 제9권3호
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    • pp.105-109
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    • 2008
  • Electrical characteristics of organic light-emitting diodes were investigated by varying a hole-size in evaporation boat in the device structure of ITO/tris(8-hydroxyquinoline) aluminum$(Alq_3)$/Al. The device was manufactured using a thermal evaporation under a base pressure of $5{\times}10^{-6}$ Torr. The $Alq_3$ emitting organics were evaporated to be a thickness of 100 nm at a deposition rate of $1.5{\AA}/s$. A cylindrical-shaped evaporation boat was made out of stainless steel with a small size of hole on top of the boat. Several evaporation boats were made having a different hole size on top; 0.8 mm, 1.0 mm, 1.5 mm, and 3.0 mm. We found that when the hole size on top of the evaporation boat is 1.0 mm, the average roughness is rather smoother compared to the other ones. Also, luminance and external quantum efficiency are superior to the others. Compared to the ones from the devices made with the hole-size of 0.8 mm boat. The luminance and external quantum efficiency of the device made with the hole-size of 1.0 mm boat were improved by a factor of seventy and thirty three, respectively. Also operating voltage is reduced to 2 V.

폴리에틸렌 보트의 내구성 평가에 관한 연구 (A Study on Estimation of Fatigue Performance of Polyethylene Boat)

  • 오정석;조석수
    • 한국산학기술학회논문지
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    • 제15권1호
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    • pp.47-54
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    • 2014
  • 선체 내구성은 기존 선급 규격에 의하여 구조 치수를 결정한 후 이러한 치수의 선체구조에 대하여 스펙트랄과 결정론적 및 간이 방법에 의하여 평가되고 있다. 이러한 방법은 선체재료를 선급 규격에서 제안하고 있는 재료로 구성하는 경우에는 적용할 수 있으나 선체 재료를 신소재로 구성하는 경우에는 적용할 수 없다. 따라서 본 연구에서는 폴리에틸렌 보트 선체에 대한 피로 손상을 평가하기 위하여 선체에 부하되는 단기간 선체 가속도를 직접 측정하고 이러한 데이터를 기초로 구조설계와 피로수명평가방법이 확립되지 못한 소형 선박의 선체 내구성을 선형누적손상 법칙으로 평가하는 방법을 제안하였다. 개발된 폴리에틸렌 보트의 경우 최대 가속도 상태에서 보트에 부하되는 최대 Von-Mises 응력은 1.8MPa로서 $1{\times}10^9$ 사이클 피로강도 5.9MPa 아래에 있고 유한피로수명개념을 적용한 폴리에틸렌 보트의 내구수명은 415년으로 평가되어져 거의 무한수명을 가지고 있다.

유선 및 도선의 복원성을 고려한 승선정원 산출 제안 (A Proposal for the Calculation of the Boarding Capacity Considering the Stability of Excursion and Ferry Boats)

  • 이리나;이홍훈;최정연
    • 해양환경안전학회지
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    • 제28권5호
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    • pp.791-799
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    • 2022
  • 유선 및 도선 중 선박길이 12미터 미만인 소형선박은 선박안전법에 따른 복원성 기준 적용이 면제되며, 유선 및 도선 사업법에 따라 승객 및 선원이 탑승 가능한 면적을 고려하여 승선정원을 정하고 있다. 이러한 유선 및 도선 중에서는 건조 이후 차양의 설치 등 복원성에 영향을 미치는 상부 구조물을 설치하는 사례도 적지 않다. 이에 본 연구에서는 상부 구조물을 설치한 도선에서 실제 발생한 전복사고의 사례를 바탕으로 해당 도선의 복원성을 추정하여 사고 원인을 분석하고자 하였다. 분석 결과, 승선정원을 초과한 상태에서 승객들이 동시에 하선하고자 기립하여 복원성이 악화된 것으로 나타났으나, 해당 도선이 승선정원을 준수하더라도 한쪽 현의 승객들이 기립하면 횡경사에 의한 전복의 가능성이 존재하였다. 따라서, 보다 안전한 유선 및 도선사업을 위하여 선박길이 12미터 미만의 유선 및 도선에 대하여 건조 및 개조 시 실선 복원성 시험에 의한 승선정원 산출, 승선정원의 총중량 한곗값 제시 등을 개선방안으로 제시하였다.

실 해상모형시험을 이용한 선미 보조동체 장착 Stepped hull 선형의 횡동요 및 저항특성 비교 연구 (A Study on the Comparison of the Rolling and Resistance Performance for the Stepped-Hull with attached a Stern-body by using Sea Model-Test)

  • 조효제;손경호;박충환
    • 한국항해항만학회지
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    • 제31권10호
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    • pp.813-818
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    • 2007
  • 선박의 선형시험설비로는 회류수조, 예인수조 등이 있으나, 소형 고속선박은 실선 대응 모형선의 축적비가 대형선에 비해 매우 작고 수조의 유속과 예인전차의 속도제한으로 고속선의 설계선속까지의 성능검증에는 한계로 작용하였다. 이에, 고속 활주형선의 선형시험 검증을 위해 실 해상모형시험기법을 정립하였다. 한편, 고속 Stepped Hull선형은 일체형 활주형 선저선형에 비하여 고속 주행시 공기공급에 따른 접수면 감소로 인하여 저항감소에 따른 속도향상과 연비절감 효과가 있으나, 선미 좌우측의 접수면 감소에 따른 횡동요 안정성이 감소되는 경향이 있다. 이에, 본 논문에서는 고속 선형시험이 가능한 해상모형시험을 이용하여 선미 보조동체 장착 유무에 따른 고속 Stepped Hull 선형의 횡동요 및 저항특성을 비교, 분석한 것이다.

실선 시험에 의한 소성어업의 동요특성 (Experimental analysis on the motion response of the small fishing boat toward wave direction)

  • 강일권;윤점동
    • 한국항해학회지
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    • 제19권1호
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    • pp.1-8
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    • 1995
  • The motion of a small boat in seas is affected in relatively higher degrees than the case of a larger ship by the specific characteristics of sea waves, i.e., the wave length and height. Ship's motion caused by sea waves is a matter of special importance to small fishing boats, because they carry out fishing job in rough seas frequently. This is an experimental study on the rolling and pitching motions of full scale ship. In the experiment, the ship's motions were measured for head, how, beam, quarter and following seas. The experiment were carried out on board the training ship Pusan 404(160 GT) in the adjacent waters off NAM HYENG JAE DO on Dec. 13th 1994. The sea condition during the measurements was that wave height 2.5m, no swell and the wind velocity of 12 m/sec. Some statistic considerations were given to the observed data by the series analysis methods and discussed in this paper.

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딥러닝 기반 소형선박 승선자 조난 인지 시스템 (Deep Learning based Distress Awareness System for Small Boat)

  • 전해명;노재규
    • 대한임베디드공학회논문지
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    • 제17권5호
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    • pp.281-288
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    • 2022
  • According to statistics conducted by the Korea Coast Guard, the number of accidents on small boats under 5 tons is increasing every year. This is because only a small number of people are on board. The previously developed maritime distress and safety systems are not well distributed because passengers must be equipped with additional remote equipment. The purpose of this study is to develop a distress awareness system that recognizes man over-board situations in real time. This study aims to present the part of the passenger tracking system among the small ship's distress awareness situational system that can generate passenger's location information in real time using deep learning based object detection and tracking technologies. The system consisted of the following steps. 1) the passenger location information is generated in the form of Bounding box using its detection model (YOLOv3). 2) Based on the Bounding box data, Deep SORT predicts the Bounding box's position in the next frame of the image with Kalman filter. 3) When the actual Bounding Box is created within the range predicted by Kalman-filter, Deep SORT repeats the process of recognizing it as the same object. 4) If the Bounding box deviates the ship's area or an error occurs in the number of tracking occupant, the system is decided the distress situation and issues an alert. This study is expected to complement the problems of existing technologies and ensure the safety of individuals aboard small boats.

선체운동(船體運動)에 관(關)한 Strip Method의 일고찰(一考察) (A Note on the Strip Methods associated with Ship Motion Problems)

  • 권영중;황종흘
    • 대한조선학회지
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    • 제8권1호
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    • pp.17-28
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    • 1971
  • The coefficients of equations of heave, pitch and coupled motion are evaluated for the small typical fishing boat(KIST-MARK Fishing Boat) with transom stern in regular head sea. And the results of computations based on eight models of strip theory are compared one another for the forward speed Froude number 0.30. There are some distinctive differences among those theories for the hydrodynamic and coupling coefficients. The former seems to be caused by the effects of the transom stern and the latter of the foward speed.

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소형선박 유압클러치 장치의 해양사고 예방 교육 만족도에 관한 조사 (Satisfaction Survey of Training to Prevent Marine Accidents on Hydraulic Clutch in Small Ships)

  • 김영운
    • 수산해양교육연구
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    • 제26권5호
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    • pp.966-978
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    • 2014
  • Currently, majority small ship's clutch for power transmission to propeller relies on multi plate hydraulic clutch regardless its size. Most of the small ships do not have a spare equipments of clutch. Furthermore, many ship engineers do not have an ability as well as enough experience to solve this problem related to the hydraulic clutch during the voyage. Therefore, any small problems cause many serious marine accidents. Once the clutch has problem, almost of all ships can not sail by itself anymore and it must be towed by salvage boat, maritime police ships, or fish guidance boat etc. In this case, all the accidents will be categorized as a marine accident and they all need to go through marine accident court inquiries. In this study, an understanding of each crew on hydraulic clutch system has been profoundly measured. Furthermore, the knowledge on an emergency navigation protocol of each crew has been also profoundly checked. Additionally, various surveys on hydraulic clutch classes has been performed and its satisfaction of crews on this topic have been carefully checked based on various feedback from students who took these courses. All of the above data from this study will be used to reduce marine accidents in current marine industry.