• 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.

• 한국정보통신학회논문지
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• 제7권1호
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• pp.26-33
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• 2003

어업무선국에서는 연안조업을 목적으로 약 10톤 미만의 소형어선과의 통신망으로 27MHz대의 주파수를 사용하는 SSB통신에 의존해 왔었다. 소형선박의 척수가 늘어나고, 어업통신본부에서는 각 도서지방을 무인화 시킴으로서 소형선박의 입ㆍ출항 및 조업사항을 관장해야 하는 통제 기능이 약화되기 시작했고, 현용 통신방식의 문제점이 드러나기 시작하면서 새로운 통신방식의 도입이 필요하게 되었다. 이들 선박은 SSB보다는 셀룰라폰을 그들의 주 통신망으로 사용하고 있으며 입ㆍ출항 신고는 물론이고 위치보고도 제대로 하지 않고 있는 실정이다. 또한 소형어선들은 항만 내외에서 운항거리를 단축하기 위해 주항로를 횡단하는 둥 선박사고가 빈번히 발생하므로, 이런 소형선박의 사고를 미연에 방지하고, 해난사고 발생시 신속한 조치를 취하기 위하여 어업무선국과 선박간의 지속적인 통신을 유지하는 것이 가장 좋은 방법이라는 것은 두말할 나위가 없을 것이다. 현재, 어업무선국과 소형어선간에 사용하고 있는 27MHz의 SSB(Single Side Band)통신방식으로는 통제가 불가능 할 뿐더러 적절한 시기에 적절한 정보를 제공할 수 없는 게 어업통신의 현실이다. 본 연구에서는 10톤 미만의 소형어선과 어업무선국간의 원활한 통신체제를 구축하여 어민의 생명과 재산을 보호함은 물론 긴급상황 발생시 효과적으로 대처하여 소형어선의 해난사고를 줄이기 위한 통신 체제로서 주파수공용방식(TRS: Trunk Radio System)의 도입을 제안하고 그 활용성을 입증하고자 한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.196-201
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• 2002

어업무선국에서는 연안조업을 목적으로 약 10톤 미만의 소형어선과의 통신망으로 27MHz대의 주파수를 사용하는 SSB통신에 의존해 왔었다. 소형선박의 척수가 늘어나고, 어업통신본부에서는 각 도서지방을 무인화 시킴으로서 소형선박의 입ㆍ출항 및 조업사항을 관장해야 하는 통제 기능이 약화되기 시작했고, 현용 통신방식의 문제점이 드러나기 시작하면서 새로운 통신방식의 도입이 필요하게 되었다. 이들 선박은 SSB보다는 셀룰라폰을 그들의 주 통신망으로 사용하고 있으며 입ㆍ출항 신고는 물론이고 위치보고도 제대로 하지 않고 있는 실정이다. 또한 소형어선들은 항만 내외에서 운항거리를 단축하기 위해 주항로를 횡단하는 등 선박사고가 빈번히 발생하므로, 이런 소형선박의 사고를 미연에 방지하고, 해난사고 발생시 신속한 조치를 취하기 위하여 어업무선국과 선박간의 지속적인 통신을 유지하는 것이 가장 좋은 방법이라는 것은 두말할 나위가 없을 것이다. 현재, 어업무선국과 소형어선간에 사용하고 있는 27MHz의 SSB(Single Side Band)통신방식으로는 통제가 불가능 할 뿐더러 적절한 시기에 적절한 정보를 제공할 수 없는 게 어업통신의 현실이다. 본 연구에서는 10톤 미만의 소형어선과 어업무선국간의 원활한 통신체제를 구축하여 어민의 생명과 재산을 보호함은 물론 긴급상황 발생시 효과적으로 대처하여 소형어선의 해난사고를 줄이기 위한 통신 체제로서 주파수공용방식(TRS: Trunk Radio System)의 도입을 제안하고 그 활용성을 입증하고자 한다.

• 대한조선학회논문집
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• 제47권3호
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• pp.321-327
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• 2010

During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For estimating resistance and moment prediction of a real ship by changing of running attitude, a model test of the ship has to be carried out. This study aims at establishing experimental techniques for a catamaran sailing yacht by changed attitude during running direction. Through the model test, drag and side force of the real ship are predicted. Also through experiment, rolling and yawing moments were considered.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 춘계학술대회
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• pp.98-100
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• 2019

In the past, there were several researchers investigating waves generated by a small boat. Wave generated by a ship can be divided into two distinct systems of waves, such as transverse and diverging waves. It is necessary to understand the behavior of a ship in waves generated by a small boat near port in the view point of ship safety. In this study, the motion of moored floater in waves generated by a small boat near port is investigated. The model test is performed in waves in a square tank in Changwon National University (CWNU). IMU and optical-based system which uses the technique of recording and capturing attitude with respect time are used for measuring 6DOF motion of the moored floater. In addition, tension gauges are used to measure the tension of mooring lines. The effect of waves generated by a small boat on motion of the moored floater near port is investigated through performing the model test in various wave directions of virtually but reasonably assumed wave scenarios.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2021년도 추계학술대회
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• pp.203-203
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• 2021

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.46-51
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• 2001

A mechanism of hovering flight of small insects which is called the Weis-Fogh mechanism is applied to ship propulsion. A model of the propulsion mechanism is based on a two-dimensional model of the Weis-Fogh mechanism and consists of one or two wings in a square channel. A model ship equipped with this propulsion mechanism was made, and working tests were performed in a sea. The model ship sailed very smoothly and the moving speed of the wing was small compared with the advancing speed of the ship.

• Journal of Advanced Marine Engineering and Technology
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• 제29권4호
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• pp.363-368
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• 2005

A mechanism of hovering flight of small insects which is called the Weis-Fogh mechanism is applied to ship propulsion. A model of the propulsion mechanism is based on a two-dimensional model of the Weis-Fogh mechanism and consists of one or two wings in a square channel. A model ship equipped with this propulsion mechanism was made. and working tests were performed in a sea. The model ship sailed very smoothly and the moving speed of the wing was small compared with the advancing speed of the ship.

• 수산해양기술연구
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• 제35권3호
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• pp.209-214
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• 1999

The turning circle of a ship is the path followed by her center of gravity in making a turn of 360$^{\circ}$degrees or more with helm at constant angle. But generally it means her path traced at full angle of the rudder. For the ordinary ship the bow will be inside and the stern outside this circle.It has been usually understood that the turning circle is not essentinally affected by ship's speed at Froude numbers less than about 0.30. However, it is recently reported that the speed provide considerable effects upon the turning circle in piloting many ships actually at sea. In this paper, the author analyzed what effects the speed could provide on the turning circle theoretically from the viewpoint of ship motions and examined how the alteration of the speed at Froude no. under 0.30 affect the turning circle actually, through experiments of actual ships of a small and large size.The main results were as follows.1. Even though ship's speed at Froude no. under 0.30, the alteration of the speed affects the turning circle considerably.2. When the full ahead speeds at Froude no. under 0.30 of small and large ships were increased about 3 times slow ahead speeds, the mean rates of increase of the advances, tactical diameters and final diameters of thease ships were about 16%, 21% and 19% respectively.3. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3 times slow ahead speed, the mean rate of increase of the turning circle elements of large ships was greater 10% than that of small ships. 4. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3times slow ahead speeds, the mean rates of increase of the tactical diameter and final diameter of thease ships were greater than that of the advances of thease ships. 5. When only alteration of speed or sip's head turning is the effective action to avoid navigational fixed hagards, reducing the speed is always more advantageous than increasing the speed in order to shorten fore or transverse distance.

• 수산해양기술연구
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• 제35권3호
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• pp.210-210
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• 1999

The turning circle of a ship is the path followed by her center of gravity in making a turn of 360$^{\circ}$degrees or more with helm at constant angle. But generally it means her path traced at full angle of the rudder. For the ordinary ship the bow will be inside and the stern outside this circle.It has been usually understood that the turning circle is not essentinally affected by ship's speed at Froude numbers less than about 0.30. However, it is recently reported that the speed provide considerable effects upon the turning circle in piloting many ships actually at sea. In this paper, the author analyzed what effects the speed could provide on the turning circle theoretically from the viewpoint of ship motions and examined how the alteration of the speed at Froude no. under 0.30 affect the turning circle actually, through experiments of actual ships of a small and large size.The main results were as follows.1. Even though ship's speed at Froude no. under 0.30, the alteration of the speed affects the turning circle considerably.2. When the full ahead speeds at Froude no. under 0.30 of small and large ships were increased about 3 times slow ahead speeds, the mean rates of increase of the advances, tactical diameters and final diameters of thease ships were about 16%, 21% and 19% respectively.3. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3 times slow ahead speed, the mean rate of increase of the turning circle elements of large ships was greater 10% than that of small ships. 4. When the full ahead speeds at Froued no. under 0.30 of small and large ships were increased about 3times slow ahead speeds, the mean rates of increase of the tactical diameter and final diameter of thease ships were greater than that of the advances of thease ships. 5. When only alteration of speed or sip's head turning is the effective action to avoid navigational fixed hagards, reducing the speed is always more advantageous than increasing the speed in order to shorten fore or transverse distance.