• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.7
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• pp.536-541
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• 2008

The Flow characteristics of a ship's propulsion mechanism of Weis-Fogh type, in which a airfoil(NACA0010) moves reciprocally in a channel, were investigated by the PIV. Velocity vectors and velocity profiles around the operating and stationary wings were observed at opening angles of ${\alpha}=15^{\circ}$ and $30^{\circ}$, velocity ratios of $V/U=0.5{\sim}1.5$ and Reynolds number of $Re=0.52{\times}104{\sim}1.0{\times}104$. As the results the fluid between wing and wall was inhaled in the opening stage and was jet in the closing stage. The wing in the translating stage accelerated the fluid in the channel. And the flow fields of this propulsion mechanism were unsteady and complex, but those were clarified by flow visualization using the PIV.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.63-66
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• 2017

All passenger ships aboard more than 36 passengers are to be able to easily find escape routes when the escape way by fire with flame spread were onboard vessel (incl. Ferry, Passenger, Ro-pax, Inland Ferry) It should be impossible by ordinary emergency lights. The international Maritime Organization (IMO) gives special requirement for luminescent evaluation onboard test procedure and applicable location of low location lighting. In order to maintain the residual light source for a certain time in the low location lighting with a strip-shaped light source, the light source material must be sufficiently exposed to the light due to the proper placement of the escape route. The lighting arrangement influence how maintain low location lighting strip luminescent which measured onboard in connection with what elements are mainly sustain luminescent.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.68-73
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• 2007

CPP is widely utilized in RoPax ship, shuttle tanker etc. due to excellent manoeuvrability in low speed, and its usage is recently increased. The CPP was almost designed by CPP maker, and its performance seemed to be not fully optimized. In this study the whole CPP design procedure was reviewed and design technology of CPP was settled down including calculation of spindle torque and MOI, which was fully confirmed by KHI CPP maker. In order to confirm the CPP design technique, a CPP for shuttle tanker was designed and its performance was verified through series of model tests. The propeller efficiency and face cavitation performance of the CPP was well improved. This CPP design technology will be contributed to the optimization of performance and cooperation with CPP maker.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12A
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• pp.1015-1023
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• 2011

In maritime communication, QoS problem caused by routing is very important. In this paper, we propose a method based on AOMDV protocol providing a route recovery mechanism when a link breaks in an active route to reduce lost packets. The results show that the proposed method can reduce packet loss ratio and delay time compared with the AOMDV.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1248-1255
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• 2006

The velocity and pressure fields of a ship's propulsion mechanism of the Weis-Fogh type, in which a airfoil moves reciprocally in a channel, are studied in this paper using the advanced vortex method. The airfoil and the channel are approximated by a finite number of source and vortex panels, and the free vortices are introduced from the body surfaces. The viscous diffusion of fluid is represented using the core-spreading model to the discrete vortices. The velocity is calculated on the basis of the generalized Biot-Savart law and the pressure field is calculated from integrating the equation given by the instantaneous velocity and vorticity fields. Two-dimensional unsteady viscose flows of this propulsion mechanism are numerically clarified, and the calculated results agree well with the experimental ones.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.492-494
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• 2013

본 논문에서는 대형선박의 내부를 실시간으로 모니터링 하기 위해 무선센서네트워크(WSN)을 사용하였고 사용자의 접근성을 높이기 위해 안드로이드 단말기를 이용하였다. 수집되는 데이터의 평균과 표준편차를 구하고 가중치평균을 도입하여 현재 수집되는 데이터가 표준편차를 초과하게 되면 경보를 통해 사용자에게 알려준다. 경보는 알람과 현재 데이터가 급격한 변화를 보이는 장소의 이름과 정보가 나타난다.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.297-302
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• 2003

This study was carried out to check the contingency planning methods under the analysis of oil spill potential and make a guide line to apply the results to the port of Busan. The expected spilled oil drift patterns are considered with the most probable scenarios under the base of the oil spill potential. The results obtained from this study are as follows: (1) Analysis method of oil spill potent was proposed and the applicability was proved by the application example to the port of Busan to make the contingency plan. (2) Responsible oil spill contingency planning methods / flow are suggested considered environmental factors and the oil spill potential. (3) The coastal waters of Busan was consist of rocky flat, man-made solid shore and beach shore. Marine traffic have high density of oil tanker and cargo ship. Also, oil tanker ship are examined in the small ships to be less than 3000t to supply oil to the ship moored / anchored as well as the large amount of oil tank / basin are located along the coast of Busan port. These systems are introduced to make in put data to the analysis of oil spill potential. (4) According to the analysis of historical records of oil spill accident in Busan, the frequency of accidents by cargo ship rank highest and 45% of accidents is caused by carelessness. about 65% of total accidents shows a small spill accident of less than $10k{\ell}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.597-607
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• 2014

An integrated ship area network has functionality of remote control and autonomous management of various sensors and instruments embedded or boarded in a ship. For such environment, a wireless bridge is essential to transmit control and/or managing information to sensors or instruments from a central integrated ship area network station. In this paper, one of reliable schemes of wireless bridge using WiMedia distributed MAC (D-MAC) protocol is proposed to increase a communication reliability. Simulation results show that the proposed wireless bridge using WiMedia D-MAC protocol guarantees reliable communications between 2-hop devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.528-537
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• 2014

As the data traffic between ships and a land station continuously increase through the shipbuilding-IT convergence, several wireless communication technologies are being studied to process large amounts of data traffic. In particular, the multi-antenna system is one of the most expected technologies to provide high throughput. This paper proposes an algorithm for the base station to select the ship in consideration of channel characteristics and the transmission angle for a beam of the land station in spatial multiplexing marine communication systems. We increase the system capacity by maximizing the received signal strength of the ship using clustering characteristic of the radio channel. Also, we reduce the time to select the ship by excluding the ship with the large interference between the beams. On our computer simulation, the proposed scheme dramatically reduces the computational complexity with a little sacrifice of the throughput.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1185-1192
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• 2015

A wireless bridge is essential to transmit control and managing information to sensors or instruments from a central integrated ship area network station. In this paper, a WPAN protocol is adopted for development of a seamless N-screen wireless service in Indoor and Ship Area Networks. Furthermore, to provide the OSMU (One Source Multi Use) N-screen service through P2P streaming in the seamless WPAN protocol, a Grid-based WPAN networking technology is proposed and analyzed. The proposed Grid-based WPAN networking technology supports multi-path and fast path-setup functions for N-screen communications. The simulation results demonstrate that the proposed Grid-based WPAN networking technology outperforms the IEEE 802.15.4 based network in terms of N-screen transmission delay.