• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1237-1242
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• 2008

A muffler design in the exhaust system is critical to provide fur low noise in shipboard spaces. In an attempt to effectively design the low noise muffler, it Is important to evaluate the performance of the muffler considering not only the noise, but also pressure drop as well. For this purpose, a test system of large exhaust mufflers fur ship propulsion systems was designed based on ISO 7235. The substitution test fur determining both the insertion loss and pressure drop of mufflers was carried out. A ship exhaust muffler is considered as a test example and the insertion loss and pressure drop were obtained.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.782-790
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• 2016

When a fire occurs on a ship that has mechanical ventilation facilities, the air supply and exhaust systems directly effect smoke diffusion. And there is a high possibility that occupant's visibility will be harmed because of smoke. In this study, the effects and risks of air supply and exhaust systems with regard to smoke diffusion given a shipboard fire analyzed with a Fire Dynamic Simulator(FDS). Suggested measures are also provided for using air supply and exhaust systems more efficiently. The results showed that, when air supply and exhaust systems were both working at the time of a fire, rather than stopping these systems as previously encouraged, continuing to operate both was an effective measure to gain evacuation time. When a fire occurred and the exhaust system was operating, also starting the air supply system near the origin of the fire was another effective approach to gain evacuation time. However, when only the air supply system was operating and a fire occurred, the air supply system accelerated smoke diffusion, so it was necessary to stop the air supply system to detect smoke diffusion as much as possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.115-122
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• 2017

Recently, the on-board equipments of vessels are getting diversifications with high technologies. With changing the trends, the shipboard network is turning to the light-weight ethernet architecture for integrated data management. For that necessity, this paper covers a development of the gateway system which gathers and processes the measured analog or NMEA data from loaded equipments to convert the messages based on IEC 61162-450 (standard for light-weight ethernet network of ships) in engine parts of small vessel. To do this, we analyzed the requirements for standardization of ship's equipments and related studies. To solve the problems of existing equipments, we defined the additional data formats (sentence formatter), developed the gateway system, and verified the utility of the developed system. Consequently, we established an interfacing framework for management and application of the generated data based on the ethernet in vessel.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.646-652
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• 2008

Recently, as the ship has undergone a development for smart ship or digital ship. PLC is communication system using the preexistence power line and using PLC as transmission medium to monitoring of equipments is an efficient way to design a system for ship. In this paper, we design and implement RFID monitoring system based on PLC for ship. This proposed system can support monitoring the moving of passenger, crew and important cargo by RHO tag data on shipboard.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.4
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• pp.285-289
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• 2012

In a coastal area, all of the vessels are always exposed to the potential risk, taking into the maritime accident statistics account over the last decades. To manage vessels underway safety, the characteristics of ship movements in a fairway should be recognized by VTS system or VTS operators. The IMO has already mandated the shipboard carriage of AIS since 2004, as stated in SOLAS Chapter V Regulation 19. As a result, the static and dynamic information of AIS data has been collected for vessel traffic management in the coastal areas and used for VTS. This research proposes a simple algorithm of recognizing potentially risky ships by observing their trajectories on the fairway. The static and dynamic information of AIS data are collected and the curvature for the ship trajectory is surveyed. The proposed algorithm finds out the irregularity of ship movement. The algorithm effectively monitors the change of navigation pattern from the curvature analysis of ship trajectory. Our method improves VTS functions in an intelligent way by analyzing the navigation pattern of vessels underway.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.183-191
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• 2013

International network standards for SOLAS ship are composed of instrument network that controls and monitors machine in real time, shipboard control network that controls and monitors system through computer by human and telecommunication network that connects ship and shore. This paper describes development of stack for instrument network protocol complied with NMEA 2000 that is IEC 61162-3 international standards for SOLAS ship and also that of engine room monitoring system using the developed stack. Developed engine room monitoring system is certified by NMEA according to standards that require to pass about 1,600 test procedures.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.98-107
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• 2017

Electric components equipped with naval shipboards must endure mechanical shock caused by various mechanical impulsive sources. Thus the components must be designed carefully and reliability test is an essential procedure before use. In this study, a new design technology applicable to a large and heavy shock generation system which can generate various specific real mechanical shocks in specified time domain was introduced. Commonly, the shock transmitted through the wall of naval shipboard consists of dual shocks. The primary shock is of a very high amplitude and very short period half-sine form. The following shock is of an exponentially decaying harmonic form of relatively longer period. Based on the different dynamic characteristics of two shocks, we proposed a sequential design procedure to determine spring and damping coefficients of the generation system. Some numerical simulation results showed the feasibility of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.55-60
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• 2012

When operating a surveillance system in the maritime environment, its stabilization performance is degraded due to undesirable disturbance motions. For accurate target pointing of a 2-axes surveillance system on shipboard, the kinematic stabilization is first applied, which compensates a deviated motion via coordinate transformations of attitude information. Resultantly, the stabilization error is no longer reduced due to less accuracy of a MEMS sensor and kinematic constraint, leading to introduction of the image stabilization as a complementary function. And for real-time execution of the present dual stabilization scheme, a HILS (Hardware In the Loop Simulation) test bed including 6-dof motion simulator has been constructed, and through the obtained HILS data, it has been confirmed that the stabilization is successfully.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.294-297
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• 2014

A Shipboard power system consists of three or four diesel generator sets connected to a grid. In case of dual fuel diesel generator sets employed LNG ship as a prime mover, large amounts of electricity are required for electric propulsion, auxiliary machinery and accommodation facilities. The electrical connection between generators through a network, torsional vibration can lead power swings. In this paper, the influence on the network by the torsional vibration of diesel generator sets in grid operation were studied. The torsional vibration characteristics were investigated and analyzed through theoretical analysis and the vibration measurement and the results were presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.69-70
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• 2015

이덕터는 구동부를 통해 공급되는 작동유체가 노즐을 통과하면서 고속으로 분출됨으로써 벤츄리 효과에 의해 노즐 출구 주위에 부압이 형성됨에 따라 흡입부를 통해 유체가 흡입된다. 이덕터의 주요 설계인자는 노즐의 직경과 스로트의 직경 및 직관부 길이 그리고 노즐과 직관부 시작점까지의 거리이다. 이 연구에서는 선박용 인라인 이덕터에 대한 기초연구로서 흡입 메카니즘을 체계적으로 해석할 목적으로 주요 설계인자를 이론적으로 고찰하고 설계인자의 변화에 따른 성능실험 가능하도록 이중원관의 형태로 모델링하였다.