• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.1-14
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• 1992

With 16 years' oceanographic data(1973-1988) of the National Fisheries Research and Development Agency and the CTD data collected by a training ship of Korea Maritime University during Nov. 6-11, 1989, the inflow path of the bottom cold water in the western channel of the Korea Strait were investigated. Temperature of the bottom water in the western channel shows the lowest in summer and large annual variation. According to the temperature distributions in the years when the bottom cold water exists in the western channel in summer, the cold water in the southwestern region of the East Sea seems to intrude into the western channel through the sea southeast 10- 15 miles off Ulsan with its properties showing slight change during advection.

• Journal of Navigation and Port Research
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• v.36 no.9
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• pp.715-720
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• 2012

This paper is to introduce the development of a LCD monitor-based pilots' ship handling simulator installed in the office of Korea Maritime Pilots Association. This simulator is composed of hardware which includes working server array, operation PC, monitor array, rudder, thruster and telegraph peripheral devices, and software which includes ship mathematical model software, ship conning software, image supporting software and so on. In this simulator, MMG mathematical model is used to create thirteen(13) ship models, which are based on sea trial data & pilots' opinion. According to requirements of pilots, virtual scenes of different port areas are built, and some required additional functions are also developed. By using this simulator, pilots can fulfill all kinds of training exercises, design of channel approaching ports, traffic safety analysis, prevention of accident research and other tasks, so as to grasp the characteristics of different ships, and accumulate experience for piloting.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.37-43
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• 2005

Recently, many ships such as fishing boats, cargo ships, high speed ferry boats are visiting Mokpo harbor. In particular, many marine accidents rave been occurred at this area because of the narrow channel, a thick fog, the existing of the shallow waters etc. However there is no suitable ships' routeing system which takes account of today's traffic situations in this area. This study aims at the settling of hazardous factors to mitigate the danger to vessels in mokpo harbor and to secure the safety qf maritime environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.566-572
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• 2011

The satellite communication is an important method for maritime communications. Binary offset carrier (BOC) signal is a promising candidate of next generation global navigation satellite systems (GNSS). Synchronization of BOC signal is one of the most important processes to demodulate BOC signal in GNSS. However, in maritime environment, the synchronization of BOC signal is suffered from the problem of side-peak of BOC autocorrelation function and multipath fading caused by the sea surface reflection. In this paper, we proposed a novel synchronization scheme which can eliminate side-peak perfectly and is robust in multipath channel. Simulation results show that the proposed scheme has better performance than conventional schemes in multipath channel.

• Journal of Digital Contents Society
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• v.16 no.6
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• pp.871-882
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• 2015

AIS-ASM is one of the studies to provide a variety of maritime safety information as well as the information on a ship's position that is their own function, and AIS-ASM has been implemented with adjustment of the relevant regulations since 2004. However, it was reported that the increased use of ASM message on the existing AIS channel affects the part of the existing AIS own function such as the transmission of the ship's position and safe-related information. Also, seamless MSP service is difficult to provide at a low transmission rate of the existing AIS channel. This study aims to reduce the marine officer's workload through automating captain's mandatory reporting items using the one of the next maritime digital communication technology (ASM2.0). For this purpose, we designed and realized the ASM2.0 protocol through analyzing domestic regulations about passenger flight and AIS-ASM message.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.74-79
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• 2008

CR technology is an intelligent technology which can sense the spectrum environment an adaptively adjust the parameters for wireless transmission. In this paper, by using CR-UWB, the spectrum efficiency of the transmission channel is largely improved; Furthermore, the interference to other system can be effectively avoided. In this paper, we propose a solution on interference problem of UWB system using cognitive radio. We use interference temperature model of cognitive radio that has proposed by FCC for estimating interference signal. Calculating channel capacity of UWB system with interference temperature, we suggest how to solve interference problem. We have used genetic algorithm in cognitive engine's calculation precess. The proposed UWB System with cognitive radio shows very efficient in solving interference problem.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.231-234
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• 2008

The paper proposed the new underwater wireless communication system fitted to non-linear acoustic channel. Generally, in non-linear acoustic channel, one used to do acoustic communication using parametric effect that is some effect caused from acoustic wave having frequency different of two primary acoustic wave frequency. In the paper, Offset PSK communication method fitted to non-linear acoustic channel was proposed, and it was demonstrated through simulations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.203-207
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• 2004

Yangtze River channel is in natural condition for a long time. There are more to be done in grade of navigation and transport. Since 1980's the rate of vessel in JiangSu channel is going up every year, especially for ocean vessels. Meanwhile, the serious factors such as no sailing at night have become a battlement causing the long period for vessels, high cost for shipowners, lower competitiveness for JiangSu ports along the Yangtze River. It also can not meet the port logistic development. After the Ships' Routeing in JiangSu has been carried out. It has improved the safety of navigation in JiangSu area and reduced the risk of pollution or other damage to the marine environment caused by ships colliding or anchoring in or near JiangSu channel. By analyzing, compareing, calculating and model forecasting. The main focus of the paper is put on the study the development of port, channel in JiangSu and efficiency in many fields. Navigation efficiency of the sailing at night; Safety efficiency of reducing the risk by ships; More efficiency of the higher cargo volumes of the other ports in Yangtze River with the increase cargo volume of JiangSu ports along Yangtze River. The purpose of this study is: To get the social and economical efficiency after the Ships' Routeing in JiangSu has been carried out. Also the role of the Ships' Routeing of JiangSu in the development of Port and Channel.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.6
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• pp.484-490
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• 2012

Experiments of circulating water channel and two dimensional numerical simulations were performed to investigate the fluctuating characteristics of pressure in moonpool. Based on the quasi-two dimensional characteristics of pressure fluctuations disclosed by the spatial cross-correlations, the numerical results showed qualitatively good agreement with experimental data. Proper orthogonal decomposition was employed to the spatial distributions of pressure fluctuations in order to find the first and second modes of fluctuations. The first mode of pressure fluctuations showed that the fluctuating characteristics of pressure were related to the behaviors of vortical structures. The velocity fluctuations were conditionally averaged to make clear that the coherent structures were responsible for the pressure fluctuations in moonpool.

• Journal of Ocean Engineering and Technology
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• v.18 no.4 s.59
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• pp.1-7
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• 2004

A simultaneous measurement system that can analyze the flow-structure interaction has been developed. This system consists of four CCD cameras, two for capturing instantaneous flow fields and two for tracking a solid body. The three-dimensional vector fields around a cylinder are measured, while the motion of the cylinder forced by the flow field is measured, simultaneously, with the constructed system. The cylinder is suspended in the working fluid of a water channel, and the surface of the working fluid is forced sinusoidally to make the cylinder bounced. Reynolds number for the mean main stream is about 3500. The interaction between the flow fields and the cylinder motion is examined quantitatively.