• Journal of the Society of Naval Architects of Korea
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• v.45 no.2
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• pp.221-228
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• 2008

This paper describes to determine optimum main particulars of warships which satisfy user's requirements in a concept design stage with minimum construction cost and maximum transportation efficiency. Present worth was used as an assessment criteria of the economical efficiency. And Pareto optimal set was used to have the optimum design.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.377-379
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• 2014

U.S. Navy had constructed 27 aegis cruisers from USS Ticonderoga(CG-47) and has been constructing aegis destroyers from USS Arleigh Burke(DDG-51). The aegis warships are the core anti-air forces of U.S. navy since 1983, the year of first aegis cruiser launching. U.S. Navy has been modernizing aegis warships to cope with advanced air threats. In this paper, it is reported that current status and analyzed report of U.S. Navy's aegis warships and aegis modernization plan.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.1
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• pp.94-100
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• 2014

In order to intercept anti-ship missiles, it is important to accurately predict the aiming point. The major factor for degrading the accuracy of the aiming point is the motions of the warships due to waves. Therefore, a stage of correcting the aiming point is required to compensate for such motions of warships. The proposed aiming point correction technique treats the changes in positions and velocity of naval guns by considering changes in the positions and velocities of the anti-ship missiles. In this paper, a ship motion estimation filter was also constructed to predict the motions of warships at the firing time of naval guns. In the simulation part, finally, the distance errors before and after aiming point corrections were compared through 6-DOF simulations.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.6
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• pp.509-515
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• 2011

The radar cross section (RCS) of warships is a crucial design factor to improve the survivability in terms of not only low observablity of the platform but also efficiency of on-board sensors and jamming devices against enemy threat. In design stage, numerical models are generated in order to quantitatively assess RCS, of which hull surfaces are modeled with the finite number of the flat plate. However, in practice, hull surfaces are permanently deformed by various kinds of loads such as winds and ocean waves faced during operations. In this paper, the effect of these shell plate deformation to RCS is numerically investigated. For this purpose, RCS calculations are carried out for various kinds of numerical models, such as single plates, dihedrals, large-sized undulate plates, and virtual warships, with some extent of permanent deformation. The results are compared with those of corresponding models without permanent deformation. It is concluded that the permanent deformation of hull surface highly influences RCS characteristics of warships, therefore they should be considered in the RCS analysis.

• Maritime Security
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• v.5 no.1
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• pp.55-83
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• 2022

For humankind, the ocean is a treasure trove of natural resources and an important area that provides major transportation routes. However, marine ecosystems are under threat amidst the global climate change crisis. This is partly due to various sources of pollution emitted from ships, shore facilities, and other sources. In response, the navies of advanced countries such as the United States, the United Kingdom, and Europe have assessed such a climate change crisis as a new maritime security threat. These countries have made early efforts to prevent marine pollution from warships. These efforts have been legally embodied. This was legislation for technical and organizational structures to be practically applied in the field. Among these navies of developed countries, France has established parliamentary and intergovernmental plans to become a leader in environmental protection at the defense level, not only in the European region but throughout the world. Within this framework, the French Navy, through its internal instruction, has inclined its legal efforts to prevent marine pollution from warships. Therefore, this study examines the legislation for the prevention of marine pollution from warships within the French Navy and compares it with the marine environmental legislation applicable to the ROK Navy. It then deduces the implications for the ROK navy, which is advancing toward a Blue-Water navy.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.339-340
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• 2016

함정 함포 사격 채점은 사격함에서 발사한 탄을 타겟을 예인하고 있는 함정에서 관찰하여 이루어 진다. 채점은 함정을 운용하는 승조원의 기량 평가와 관련 있기 때문에 공정성이 중요하다. 명중 여부는 타겟 주위에 발생하는 물보라를 관측하여 결정하는데, 물보라의 경우 사격 이후 수 초 내에 없어져서 예인함의 인원이 육안으로만 관찰해서는 공정한 채점을 할 수 없다. 캠코더등의 영상기록장치를 이용하여 사격을 기록하고 컴퓨터비전을 활용하여 채점의 공정성을 높일 수 있다. 본 논문에서는 컴퓨터 시스템을 활용하여 함정 사격 채점 시스템을 구현할 때 시스템이 갖추어야 할 기능과 컴퓨터비젼의 활용방법 및 함정에 설치되어 있는 전투체계 시스템을 활용하는 방법에 대하여 알아보고 실제로 시스템을 구현해 본다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.4
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• pp.71-77
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• 2001

In this paper, stress wave propagation characteristics of MR(Magneto-rheological) inserts are experimentally investigated. Generally, stress waves of structures such as warships or submarines are induced by shock waves from underwater explosion. Their fatal effects on the shipboard equipments or structures damage the performance of warships. But, such a problem can be solved by controlling the stress waves propagating through structures by means of MR inserts. MR insert consists of two aluminum layers and MR fluid filled in between. Two piezoceramic disks are embedded on the host plate as a transmitter and a receiver of stress waves. Pulse waves are generated by the transmitter and they reach to the receiver through the MR insert. Permanent magnet and magnetic coil are used to produce magnetic field at the MR insert. In the presence of magnetic field, MR particles are arranged in chains parallel to the magnetic field such that the transmitted stress waves are reduced. Attenuation of stress waves is experimentally investigated.

• Structural Engineering and Mechanics
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• v.65 no.3
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• pp.243-250
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• 2018

The use of blast hardened bulkheads (BHBs) is an effective vulnerability hardening technique for improving the survivability of naval warships when internal explosions occur due to being shot by an anti-surface missile. In this paper, a new concept of BHBs reinforced by aluminum (Al) foam is proposed. The new concept can significantly reduce the blast pressures transferred to bulkheads and, unlike conventional BHBs, can be easily installed to operating naval warships. Chamber model blast tests were performed to demonstrate the effectiveness of the Al-foam BHBs and the results are further supported by numerical simulations. Finally, a practical preliminary is proposed for the Al-foam BHBs.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.1
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• pp.55-64
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• 2022

Identifying warships contacted at sea is important to prepare for threats. It is necessary to obtain a basis to identify warships. In this study, we propose a 2-step model that acquires the warship's type and hullnumber with identification information from the warship images. The model classifies the warship's type and detects its hullnumber area by applying object detection, then recognizes hullnumber through text recognition algorithms. Proposed model achieved high performance by using state-of-the-art deep learning algorithms.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.14-16
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• 2007