The first step is to determine the principal dimensions of the design ship, such as length between perpendiculars, beam, draft and depth when accomplishing the design of a new vessel. To make this process easier, a database with a large amount of existing ship data and a regression analysis technique are needed. Recently, deep learning, a branch of artificial intelligence (AI) has been used in regression analysis. In this paper, deep learning neural networks are used for regression analysis to find the regression function between the input and output data. To find the neural network structure with the highest accuracy, the errors of neural network structures with varying the number of the layers and the nodes are compared. In this paper, Python TensorFlow Keras API and MATLAB Deep Learning Toolbox are used to build deep learning neural networks. Constructed DNN (deep neural networks) makes helpful in determining the principal dimension of the ship and saves much time in the ship design process.

해상에서 전복사고가 발생하면 선박이 복원성을 잃고 전복되는 과정에서 승선 하고 있던 선원의 사망․실종․부상 등 인명사고가 발생하는 동시에 전복에 따 른 선체 침수 및 침몰로 인해 선박 소유자는 엄청난 경제적 손실을 입게 된다. 따라서 동일한 전복사고가 발생하는 것을 방지하기 위해서는 현행 선박길이24미터 이상 어선에만 적용되는 복원성검사 및 만재흘수선 표시 규정에 대하 여, 허가받은 어업의 형태와 어구의 종류를 고려하여 총톤수 20톤 미만의 소형 어선으로 확대할 필요가 있다. 또한 기중기 등 조업에 사용하는 중량 어로설비 설치 유무에 따라 추가적인 복원성검사 및 만재흘수선을 표시하고, 사고선박에 대해서는 동일한 사고가 다시 발생하지 않도록 임시검사 규정을 강화하는 등 실질적이고 효과적인 검사 규정이 필요하다. 이에 따라 이 연구에서는 2017년부터 2021년까지 최근 5년간의 해양안전심판 원 재결서를 바탕으로, 자주 발생하고 있는 길이 24미터 미만의 소형어선 전복 사고 발생 원인과 소형어선 검사 규정의 문제점에 관한 연구를 통한 어선검사 규정 개선방안을 모색하였다.

This study was conducted in order to improve opening efficiency of the miniaturized small-scale net for anchovy boat seine gear to reduce the fleet size. Field experiment was performed to observe geometry of nets by catcher boats. When the distance between the two ships was 150, 300 and 450 m and the speed of towing nets was 0.6, 0.9, and 1.2 kt, the vertical opening and actual opening of each part of the miniaturized small-scale net was as follows: the front part of the wing net, 6.8-9.5 m, 45-63%; the middle part of the wing net, 16.1-30.7 m, 34-65%; the entrance of the inside wing net, 21.6-41.2 m, 44-84%; the square and bosom, 17.4-34.0 m, 38-75%; the entrance of the body net, 16.5-29.4 m, 36-64%; the entrance of the bag net, 14.5-21.9 m, 70-106%; the flapper, 6.7-7.7 m, 81-83%, and the end of the bag net, 8.6-10.9 m, 64-81%. The tension of towing nets was measured to be 2,734-6,812 kg approximately, which indicates that the fleet can tow nets with 350 hp, the standard engine horse power. The fishing operation time was shortened comparing to existent net with the large-scale buoy attachment operation. It was also possible to operate the ship without fish detecting boat.

본 연구는 소형 고속정의 운항한계를 검토하기 위하여 수행되었다. 일반적으로 내항성능의 검토는 선형의 결정 단계 전에 이루어지지만 본 연구는 선박의 건조가 완료된 후에 이루어졌다. 검토 결과, 종동요, 수직 및 수평가속도, 슬래밍의 운동성능은 특정한 조우각을 제외하고는 만족하였으나 갑판침수의 경우에는 해석을 수행한 모든 조건에서 만족하지 않았다. 이것은 대상선박의 크기가 소형이기 때문에 선박의 속도나 파도와의 조우각보다는 해상상태가 설정한 내항성능 기준의 만족 여부에 더 큰 영향을 미쳤기 때문으로 보인다.

This study is concerned with the development of the basic planing hull form of small fishing boat in 25 knots high speed. A series of model test to determine the optimum performance hull form of actual fishing boat with 10 gross tonnage was carried out for 5 models made available planing hull form in the circulation water channel. Model test was performed with the resistance test to study the hydrodynamic characteristics of model ships and the sinkage and trim measurement to investigate the stability of model ships and also the wave pattern observation to analyze the effectiveness of model ships. As the result, the planing hull form of P-4 with deep V type bow can be derived as the best hull form with good performance especially in ship's resistance efficiency showing less residual resistance and sinkage and trim and the spray effect, etc..

Marine casualties of vessel are serious problems on social and national aspects, because it results in sacrifice of lives, a great lose of properties and marine pollution. According to recent statistics of marine casualties of vessel, fishing boats are more likely to be ended in the casualty, and especially, small fishing boats cause much more accidents than any other big vessels. Most of marine casualties were caused by the human factors such as poor watch keeping, inadequate manoeuvering and negligent action for engine, etc. This study is intended to provide navigator of small fishing boat with a specific information of necessary to assist both the manoeuvering and the avoidance of capsizing. The manoeuvering characteristics of ship can be adequately judged by the results of typical ship trials manoeuvres. For this purpose, the author measured the roll responses of a small fishing boat in waves using the real sea experimental measuring system, and analyzed the experimental data by the statistical and spectral analyzing methods to get the characteristics of the roll motion responses of the small boat through the wave directions and the ship's speed.

최근 개발되고 있는 전자자기 컴퍼스를 이용한 소형어선의 항행자동화시스템을 구축하기 위한 기초 연구로서, 부두에 계류된 선박에서 각종 장비의 가동 시켰을 때 나타나는 컴퍼스 오차 변화를 측정하여 비교 분석한 결과를 요약하면 다음과 같다. 1. 목선에서 85kW의 집어등을 점등하였을 때, 조타용 자기컴퍼스는 7˚편서되었고, 전자자기 컴퍼스는 13˚~16˚ 까지 편서되는 것으로 나타났다. 2. FRP 어선에서 13OkW의 집어등을 점등하였을때, 전자자기 컴퍼스는 19˚~23˚ 까지 편동되는 것으로 나타났다. 3. 강선에서 225kW의 전력으로 각종 장비를 가동 시킬 때, 가동전과 비교하여 컴퍼스 오차의 차분은 조타용 자기 컴퍼스에서는 13˚ 편서되고, 전자자기 컴퍼스는 상갑판에서는 68˚ 편서되었고, 선수루 갑판과 조타실 및 컴퍼스갑판에서는 각각 16˚, 32˚, 20˚ 편동되어 나타났다. 4. 소형어선의 항행자동화시스템에 전자자기 컴퍼스를 활용하기 위해서는 선박내에서 사용하는 각종 장비에 의해 발생하는 컴퍼스 오차를 측정하여 적절하게 수정하여 사용해야 할 것으로 판단된다.

Most of the underwater noise emitted by small fishing boat are owing to vibration of main engine and generator etc.. This paper describe on the spectrum analysis of underwater noise by engine generating in small fishing boat in order to build up comfortable environment for fisheries man and to reduce ambient noise. The obtained results are summerized as follows:1. When the underwater noise of 10ton class fishing boat measure and the frequency spectrum in varied revolution of engine 750, 900, 1000rpm analyze, the frequency pattern is similar to each other, the faster revolution of engine increase, the higher frequency spectrum level becomes. 2. In comparison of spectrum level of underwater noise between 10ton class and 14ton class fishing boat, the former level is higher than the latter. 3. Frequency spectrum pattern of two 14ton class fishing boat is similar to each other but spectrum level is a little difference, it is suggested to different by fitting condition of engine.

An electrical power generation system driven by main engine shaft, briefly SG system for middle or small size fishing boat is studied experimently. In the SG system, power transmission is performed by a variable displacement hydraulic pump driven by the main engine and a constant displacement hydraulic motor. It was verified that the SG system enabled the generation of electrical power with constant frequency regardless main engine speed. In the SG system, setting reference frequency, sensing generator output frequency and setting controller parameters are performed by performed by programming in a microcomputer, so a countermeasure for physical situations of control object is very easy. Futhermore, the SG system has following features; low initial installation cost, wide freedom of installation in engine room, advantage of application in existing ships, especially fishing boat with hydraulic fishing equipments.

국산 소형어선용 예연소실식 디이젤기관에 혼합연료유(정유+중유)를 사용할 경우 혼합연료유의 성질, 연소특성 및 기관성능에 관하여 실험한 결과를 요약하면 다음과 같다. 1) 혼합연료유의 혼합비율(중량비율)이 증가함에 따라 비중은 선형적으로 증가하였고, 점도-온도 곡선은 Walther-ASTM 식과 일치하였으며, 착화성지수인 CCAI의 값은 기울기 1.0에 가까운 직선으로 증가하였다. 2) 동일운전조건에서 착화지연은 CCAI의 값이 810(혼합비율 60%)까지는 미소하게 증가하였으나, 그 이상의 값에서는 현저하게 증가하였다. 따라서, 혼합연료유의 착화성을 나타내는 CCAI의 값은 810 이상에서 적용하는 것이 타당하다. 3) 연소최고압력은 혼합비율 40%까지 증가하다가 감소하였으며, 그을음농도는 60%부터 현저하게 증가하였으므로, 본 실험에서 무그을음 연료비절감의 안전운전 혼합비율은 50%가 적당하다

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.