• 한국소음진동공학회논문집
• /
• 제13권8호
• /
• pp.637-644
• /
• 2003

Airborne noise is one of the considerable environmental factors for navy ship personnel who should accomplish their tasks in restricted ship spaces against adverse health effect of noise. However, it is difficult to find studies on actual condition of airborne noise for navy ships. In this study, we measured airborne noise levels at 379 compartments of 33 Korean navy ships. Using the measured data, we presented mean values and their standard deviations of measured noise levels with factors of ship type, compartment category, and operation mode. Additionally, we evaluated the mean value and cumulative probability of airborne noise levels of compartments with those of the US navy ships. These results can be rationally used in making the proper airborne noise criteria of the navy ship for the future.

• International Journal of Ocean System Engineering
• /
• 제3권4호
• /
• pp.175-187
• /
• 2013

Moonpools are vertical wells in a floating body used onboard many types of vessels like Exploration and drilling vessels, Production barges, Cable-laying vessels, Rock dumping vessels, Research and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modelled and tested in the wave basin. The pretensions of the lines are varied by altering the touchdown points and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs calculated for various situations provide better insight to the designer.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권4호
• /
• pp.553-561
• /
• 2009

This paper presents development of ROV-type underwater robot capable of cleaning ship hull in automatic mode. The purpose of developing this robot is for underwater cleaning to secure the safety of divers who inspect and clean the ship hull. The robot consists of the cleaning system with rotating brush mechanism, a car-like driving mechanism, inspection system using video, and overall control system for underwater communication and operation. In this paper, we present overall design process of the cleaning system and operating system and technical contents of the overall control system for the underwater cleaning robot.

• 한국음향학회지
• /
• 제29권1호
• /
• pp.10-17
• /
• 2010

수중에서 소나를 이용하여 표적을 탐지하고자 할 때 자함에서 발생되는 소음을 감소시켜 표적의 탐지성능을 향상시키는 것은 매우 중요한 일이다. 본 논문에서는 수상함에서 선체고정형소나(HMS)를 사용하는 경우 두 가지 운영모드에 대하여 자함의 소음감소 성능을 분석하였다. 운영자모드에서는 ALE(Adaptive Line Enhancer)기법을 적용하여 자함신호의 광대역 성분을 감소하므로 토널 성분의 탐지성능을 향상하였으며, 자동모드에서는 주 입력신호와 상관관계를 가진 기준 입력신호를 선정하여 조향 방위로 유입되는 잡음신호를 제거하였다. 적응필터를 설계하기 위하여 NLMS(Normalized LMS)알고리즘을 이용하였으며 실제 해상실험 데이터를 이용하여 시뮬레이션을 수행하므로 제안한 기법의 성능을 확인하였다.

• 한국정보통신학회논문지
• /
• 제24권9호
• /
• pp.1202-1208
• /
• 2020

현재 4차 산업혁명 시대에 발맞춰서 선박 분야에서는 인공지능 요소를 접목하여 미래를 대비하여야 한다. 그리고 자율운항 선박 등장에 대한 전력관리 분야에서도 이에 대한 대응이 필요하다. 본 연구에서는 머신러닝의 DNN(Deep Neural Network)을 이용한 배터리 연동형 전력관리시스템(BLPMS, Battery Linked Power Management System) 알고리즘을 제안한다. 실험을 위하여 LabView를 통한 선박 데이터를 바탕으로 운항모드별 선박 전력소비량의 패턴을 학습하고 Python을 통해 배터리의 상태를 도출하여 발전기와 배터리의 연동의 유연성을 확인하였다. 실험의 결과 배터리의 충·방전을 통해 발전기의 저부하 운전이 감소되고, LNG의 1%의 연료소모량 감소를 통하여 경제성 및 신뢰성을 확인하였다.

• 한국기후변화학회지
• /
• 제6권4호
• /
• pp.345-355
• /
• 2015

In this study, we researched a space allocation method of emissions from domestic coastal shipping (passenger ship, cargo ship, fishing boats). We were building a geographic information data that is used in GIS for emissions of space allocation, and presented a methodology capable of performing the space allocated for each grid by calculating the emissions. Passenger ships were assigned emissions of routes each the ship that operated at a fixed. Emissions of crusing mode of cargo ship, was equally assigned to the safe operation line, which is defined for domestic cargo ship. Also, Emissions of maneuvering (moving into or out of port) and hoteling (operations while stationary at dock), was assigned in consideration of anchorage in the major port. Fishing boat was evenly allocated monthly emissions in the country every month fishing grounds formation zone. Based on these results, it tries to provide the basic data that can be used when you want to create a local government measures to reduce scenario in the future.

• 한국항해항만학회지
• /
• 제34권9호
• /
• pp.693-698
• /
• 2010

In port and its approach channel, traffic accidents such as collision, aground, minor collision have reached about 77% of total marine casualty in the area. In this paper, an attempt to enhance the safe navigation was proposed by offering marine traffic supporting system which helps VTS operator assist vessel effectively with the quantitative assessment on difficulty of each vessel. The system collects navigation data from onboard AIS, assesses the data in assessment mode to analyze the navigation difficulties of each vessel and displays the degree of danger of each vessel on the ECDIS in real-time to decide the intervention time or order of priority for VTS operator. The effectiveness of the system was verified by the VTS operators in Korea.

• 한국항해항만학회지
• /
• 제35권9호
• /
• pp.749-753
• /
• 2011

A leisure ship has a stand-alone type power system, and a generator is in use on this condition. But the generator cannot be operated in condition of leisure activity, ocean measurement and etc, because of environment and noise. Recently, renewable energy system is connected with power system of the leisure-ship for saving energy. The renewable energy system can not supply the stable power to leisure-ship because power generation changes according to weather condition. And most of the leisure ship is operated without methodical power management system. This study's purpose is to develop SPMS(Smart Power Management System) algorithm using the renewable energy (photovoltaic, wind power and etc.). The proposed algorithm is able to supply stable the power according to operation mode. Furthermore, the SPMS manages electric load (sailing and communication equipment, TV, fan, etc.) and reduces operating times of the generator. In this paper, the proposed algorithm is realized and executed by using LabVIEW. As a result, the hour for operating the generator is minimized.

• 해양환경안전학회지
• /
• 제19권5호
• /
• pp.531-537
• /
• 2013

본 연구에서는 한국해양대학교 실습선 한바다를 이용하여 선박의 입 출항 및 약 150 rpm의 정속 운항 할 때 주기관에서 배출되는 배기가스를 실시간 계측하였다. 실측 결과 질소산화물의 농도는 정속 운항시 800 ppm 에서 1,000 ppm 사이인데 반해, 입 출항시에는 210 ppm 에서 1,230 ppm 까지 큰 범위에서 값이 변화하였다. 일산화탄소의 농도 역시 정속운항 상태 보다 입 출항시 측정값의 변화가 크게 나타났다. 이러한 결과는 입 출항시 가능한 한 주기관의 부하변동이 급격히 발생되지 않도록 하는 선박 조종 스킬이 필요하다는 것을 의미한다. 또한, 배기가스 저감 기술의 적용에 있어 입 출항시와 정속 운항할 때 그 차이를 고려할 필요가 있다는 것을 나타낸다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제26권3호
• /
• pp.313-319
• /
• 2002

Since the oil crisis in 1970, a great deal of effort has been made to develop automatic electric load sharing systems as a part of the efforts to save energy. A large scale electric generating system composes more than two generators whose characteristics may be different. When such a system is operated individually or in parallel, the lagrange multiplier's method has difficulty in achieving optimal load distribution because generators usually have the limitations of the operating range with inequality constraints. Therefore, a suitable operating mode of generators has to be decided according to the selection of the generators to meet electric power requirements at the minimum cost. In this study, a method which solves the optimal electric load distribution problem using the dynamic programming technique is proposed. This study also shows that the dynamic programming method has an advantage in dealing with the optimal load distribution problem under the limitations of the operating range with inequality constraints including generator operation mode. In this study, generator operating cost curve of second order equation by shop trial test results of diesel generators are used. The results indicate that the proposed method can be applied to the ship's electric generating system.