• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.261-263
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• 2013

방충재(Fender)는 함정의 안전한 접안, 계류 및 선체를 보호하기 위하여 설치된 중요한 안벽시설 중 하나이다. 기존의 고무 방충재는 초기변형 28~30% 정도에서 가장 높은 반력이 발생하여 함정에 지속적인 힘을 가해주기 때문에 선체에 찌그러짐(dent)이 발생하게 되고, 검정색이 착색되기도 하여 선체에 심대한 훼손이 발생하게 된다. 이런 문제점을 개선하기 위하여 이 연구에서는 초기 반력이 적어 선체의 손상을 일으키지 않고 착색이 되어 선체가 더러워지는 현상을 막는 폼필드 펜더(Foam Filled Fender)를 직접 제작하여 그 결과를 제시하기로 한다.

• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.199-207
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• 2003

In the combat environments at the sea, the naval ships should have enough structural integrity to perform the task under the enemy's attack and possible damages. Although the naval ships can be damaged from the enemy's attack, those damages should be minimized and the naval ships must maintain their combat capabilities continuously after recoveries from the damages. Therefore, it is ve교 important for modem naval ships, especially combat naval ships, to ensure the survivability. This paper reviewed the developing procedure for the technique of the naval ships structures and described method, especially box girder system considering survivability. The efficiency of box girder is examined by numerical simulation, and it is found that the establishment of box girder is a good design method to improve the survivability.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.277-283
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• 2015

MS(Mild Steel), HTS(High Tensile Steel), HYS(High Yield Steel), AL(Aluminum Alloy) and Composite Materials are used for vessels. Steel Materials are mostly used for vessels because body of a ship have to perform the basic functions such as watertight, preserving the strength and supporting the equipments. The vessels primarily carry out a mission at ocean, so that body of a ship is necessarily rusted. There are several methods to protect the corrosion of vessels such as painting, SACP(sacrificial anode cathodic protection) and ICCP(impressed current cathodic protection). For the sacrificial anode cathodic protection, Al and Zn alloys are normally used. Heavy metals are added to the Al and Zn Alloys for improving the corrosion properties but they are so harmful to the human and environment. Therefore, the use of these heavy metals is strictly regulated in the world. In this paper, Al and Zn Alloys are made by adding the trace elements(Ma, Ca, Ce and Sn) which is not harmful to the human and environment. SEM, XRD, Potentiodynamic Polarization test and Current Efficiency test are conducted for evaluation of Al and Zn Alloys. As a result of the experiment, Al-3Zn-0.6Sn and Zn-3Sn Alloys are more efficient than other Alloys.

• Journal of the Korean Magnetics Society
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• v.24 no.4
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• pp.128-133
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• 2014

The control and reduction of the magnetization of naval vessel is important technologies for safety against torpedo and sea mine installed magnetic sensors. In general, we used to conduct as a magnetic treatment for permanent magnetization reduction and to compensate induced magnetization using on-board-degaussing system for the naval vessel's magnetic stealth. Navies have operated magnetic treatment facility in order to protect from sea mines. LIGNex1 Corp. has developed the magnetic treatment facility for the korea navy.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.1
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• pp.61-67
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• 2024

A naval mine is an effective weapon system implemented for defending defends ports and seas. A mine is an underwater weapon that poses a great threat to ships sailing over the sea from shallow areas. Most of the influence-type naval mines detect magnetic field signals from ships and determine the final time of fire. Therefore, the level of underwater electro-magnetic signatures of ships is a key requirement for determining the survival of ships in wartime situations where mines are emplaced. The main reason why the high manganese steel is attracting attention for naval ship hulls is its nature as a non-magnetic steel. The non-magnetic hull does not generate electro-magnetic signatures; thus, it has the advantage improving the stealth of the ship. In this paper, I examine whether this material can be applied in the hulls material of naval ships that must be ableto reduce underwater electro-magnetic signatures by considering the non-magnetic characteristics of the first developed high manganese steel in the world.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.165-166
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• 2013

함정의 추진체계로 전기추진체계가 선정될 경우 대용량의 전동기 및 전력변환장치가 설치된다. 전동기를 구동하여 추진력을 얻기 위해서는 발전기에서 공급하는 AC 전력을 AC에서 DC 다시 DC에서 AC로 변환하는 과정을 거치게 된다. 이 과정에서 전력용 반도체의 On/Off 동작에 의해 높은 전압상승률 (dv/dt)이 발생하며 이로 인해 함정의 선체를 통해 흐르는 누설전류가 발생하여 인접 장비에 영향을 미치게 된다. 본 논문에서는 전기추진 함정의 전자기 간섭(EMI) 현상 발생 원인에 대해 분석하고 이를 저감시키기 위한 방법으로 Drain wire를 적용하고 그 효과에 대해 분석한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.7-12
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• 2019

The naval surface vessels, which were often exposed to harsh marine environment, tended to be corrosive due to military operations on various sea-areas and courses. Although R.O.K Navy applied various methods to protect further corrosion, the hull corrosion occurred due to cavitation were found on the naval surface vessels at regular and occasional docking. Hull corrosion was a critical factor directly to affect the lifetime of ships and their operational capabilities adversely. In this paper, EH 2350, which was the main anticorrosion paint used by R.O.K. Navy, was compared with DuraTough DL by used by the U.S Navy to collect materials related to anti-corrosion paint. In addition, the paint compatibility verification was conducted through wear abrasion test. Assuming that it was exposed to sea-environment various both abrasion cycle and weight for objective verification. by varying both the abrasion cycles and weights. In this study, the reliability of the EH 2350 conformity, which was used in Naval surface vessels, was secured.

• Journal of the Korean Magnetics Society
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• v.21 no.5
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• pp.167-173
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• 2011

Underwater static magnetic field signature for the naval ship has been widely used as the detonating source of the influence mine system because it is possible to make an accurate target detection in the near field although the magnetic field falls off relatively fast with distance in comparison with the underwater radiated noise signal. In this paper, we describe the prediction results about the underwater static magnetic field by the ferromagnetic hull, the internal structures and the main on-board equipment for the target vessel using the commercial FEM software. Also we analyze the degaussing effectiveness for the target vessel through the degaussing coils arrangement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.465-473
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• 2019

This paper is meaningful as the first case where a 4 - sided hull-fixed phased array radar was installed on a mast separated from Korea and the alignment was verified. The mechanical alignment method was studied for accurately mounting two separate masts for naval ships and the 3D scanner for alignment. Hull-fixed phased array radar uses very high frequency, so the short wavelength can cause a phase difference of the device due to the small positional error. Since the array antenna is fixed with the hull, it has higher accuracy control than the rotary radar for 4 array surfaces. The study describes a method of checking the flatness of two radar masts manufactured at a factory, a method of aligning masts in a shipyard, and a method of aligning four array pad mounting surfaces. As a tool for this, a 3D laser scanner and a software-based method for comparing survey results with 3D CAD are used. This paper is meaningful as the first example of installing a four-sided hull-fixed phased array radar on a separate mast from a Korean naval ship and deriving a mechanical alignment method.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.1-9
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• 2021

In actual battlefield environment, the naval ships which have specific missions have to respond to the attack of hostile forces. Especially, in modern warfare, the importance of the survivability of naval ships are increasing due to the high lethality of armaments. Naval ship survivability is generally considered to encompass three constituents, susceptibility, vulnerability and recoverability. Recently, among these three constituents, many researches on vulnerability have been conducted. However, for the vulnerability of naval ships, most of researches are aimed towards the detailed design stages where implementing changes is heavily constrained or even impractical. In this paper, vulnerability assessment model for naval ships on a theater engagement is developed by using M&S technique. By using this model, the characteristics of platform and armaments are reflected on the damage of naval ship. The basic logic of damage assessment is also considered in detail. The damage status of the naval ship is quantified by defining a representative state index of onboard equipment for each system.