• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.607-608
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• 2013

무선 애드훅 네트워크에서는 무선링크의 성능을 표현하는 다양한 품질 척도가 있다. 그것은 노드가 움직임이 없는 상태에서 주변 무선 상태를 반영한다. 하지만 해상 환경에서는 선박의 이동성 뿐만 아니라 바람과 파고에 의해 선박이 움직이는 특성이 있다. 따라서 선박에 위치한 안테나의 흔들림을 유발하여 신호의 수신을 불안정하게 만든다. 본 논문은 선체운동에 따른 무선 링크 성능을 분석한다. 이를 위해 자이로 센서를 이용하여 서로 다른 해상 환경에서 선체운동을 측정 및 분석하고, 하드웨어 및 소프트웨어에 의한 무선 링크 안정화 방안을 제시한다.

• Bulletin of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.33-35
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• 1994

본 고에서는 선체국부팬널의 대종을 이루고있는 판요소, 보강판, 복판팬널 및 복합재료적층판의 진동특성을 구하는 근사방법으로서 주로 Rayleigh-Ritz방법을 적용한 연구결과들을 정리하였다. 이를 통해 향후 추가로 연구가 이루어져야 할 내용을 다음과 같이 도출하였다 1) 팬널주위의 경제조건으로서 탄성구속을 고려 할 수 있도록 정식화는 이루어져 있으나 실제 선체 팬널의 탄성구속도를 구하는 방법이 정립되어 잇지 못하기 때문에 해석결과의 정도 문제가 발생한다. 따라서 해석정도의 향상을 위해 실제 선체팬널의 탄성구속도에 대한 연구가 수행되 어야 하며, 이와 같은 연구는 조선소에서 이루어지는 것이 타당한 것으로 사료된다. 2) Mindlin 판, 복합판널, 복합재료적층판에 대한 정식화에서 경제조건이 회전방향탄성고속만 고려되고 힁방향 변위는 고정되어 자유와 단순지지 사이의 경제조건은 고려될 수 없으므오 이 에대한 보완 연구가 이루어져야 한다. 3) 본 고에서는 접수효과에 대한 연구결과의 소개는 없었으나, 이에대한 현재까지의 연구는 주로 평판에 대해 이루어졌다. 화물창내 국부판널 또는 이중저의 진동해석을 정도 노ㅍ게 수행하기 위해서는 보강판 및 복판팬널의 접수효과에 대한 연구가 적극적으로 이루어져야 한다.

• Computational Structural Engineering
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• v.10 no.2
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• pp.13-26
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• 1997

본 고에서는 선체구조의 좌굴 및 최종강도에 관한 연구현황을 조사 분석하고자 한다. 먼저 대표적인 구성부재인 판 및 보강판의 좌굴 최종강도에 관한 연구현황을 분석하고, 다음으로 선각거더의 최종붕괴강도에 관한 연구동향을 분석하고자 한다.

• Journal of Korea Ship Safrty Technology Authority
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• v.15
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• pp.31-44
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• 2004

어선전복사고의 원인을 분석하여 이러한 사고가 선체복원성, 예비부력, 방수구 및 잘못된 선체운용술과 어떠한 인과관계가 있는지를 판단하고 이에 대한 개선점을 도출코자 하였다.<중략>

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.191-197
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• 2016

The shaft system of a vessel becomes stiffer because of larger engine power, whereas the hull structure becomes more flexible because of scantling optimization conducted by using high-tensile thick steel plates. The draught-dependent deformation of the hull affects each bearing offset and reaction force comprising the subsequent shaft system. This is the reason that more sophisticated shaft alignments are required. In this study, an FE analysis performed under the expected operating conditions of two (2) vessels, as maximum draught change and to analyze the shaft alignment using the relative bearing offset change, which was derived from an FE analysis of the 50,000 DWT oil/chemical tanker, which has become an eco-friendly vessel in recent years. Based on this, the influence of the hull deflection on the bearing offset was reviewed against results for shaft alignment conditions.

• Journal of the Korean Society for Marine Environment & Energy
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• v.1 no.2
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• pp.82-95
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• 1998

In this paper, two series of numerical simulations are performed using LS/DYNA3D: The first series of numerical simulations are collision events between a 310,000 DWT double hull VLCC (struck ship) and two 35,000 and 105,000 DWT tankers (striking ships). Collisions are assumed to occur at the middle of the VLCC with the striking ships moving at right angle to the YLCC centerline. The second ones, grounding accidents of two 40,000 DWT Conventional and Advanced Double Hull lanker bottom structures, CONV/PD328 and ADH/PD328 models. The overall objective of this study is to understand the structural failure and energy absorbing mechanisms during collision and grounding events for double hull tanker side and bottom structures, which lead to the initiation of inner shell rupture and cause the kinetic energy dissipation to bring the ship to a stop. These numerical simulations will contribute to the estimation of damage extents of collision and grounding accidents and the future improvements in lanker safety at the design stage.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.288-294
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• 2016

In modern ships, the shafting system often becomes stiff owing to the high engine power, whereas the hull structure becomes more flexible owing to optimization using high-tensile-strength thick steel plates; therefore, more sophisticated shaft alignments are required. In this study, strain gauge-based measurement was conducted under five vessel operating conditions and bearing reaction forces and hull deflections affecting shaft alignment were analyzed for a 50,000 dead weight tonnage oil/chemical tanker that has gained repute as an eco-friendly vessel in recent years. Furthermore, the analytical results from each technique-theoretical calculation, jacking ups, and strain gauges-were cross-checked against each other in order to enhance the degree of accuracy and reliability of the calculation.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.5
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• pp.383-389
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• 2016

In this paper, we present the hull blasting machine with vision-based weld bead recognition device for cleaning shipment exterior wall. The purpose of this study is to introduce the mechanism design of the high efficiency hull blasting machine using the vision system to recognize the weld bead. Therefore, we have developed a robot mechanism and drive controller system of the hull blasting robot. And hull blasting characteristics such as the climbing mechanism, vision system, remote controller and CAN have been discussed and compared with the experimental data. The hull blasting robots are able to remove rust or paint at anchor, so the re-docking is unnecessary. Therefore, this can save time and cost of undergoing re-docking process and build more vessels instead. The robot uses sensors to navigate safely around the hull and has a filter system to collect the fouling removed. We have completed a pilot test of the robot and demonstrated the drive control and CAN communication performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1551-1561
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• 2012

Boat or yacht hulls are mainly built using FRP composite materials. FRP boat hull manufacturing has been restricted since 2000 under international regulations on ocean environment safety. FRP composite materials cannot be recycled and require more than 100 years to biodegrade. Therefore, alternatives to FRP have been proposed by many boat builders. Steel, aluminum, and FRP are commonly used as boat hull materials. Their design specifications are proposed as Korean register of shipping. However, the design specifications for inexpensive materials for a small boat have not yet been studied. Small shipbuilders manufacture and sell HDPE canoes or HDPE kayaks. In this study, a hull form was designed based on actual boats. The thickness of an HDPE boat hull was determined based on ISO 12215-5 structural design specifications.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.97-105
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• 1996

For the minimum weight design of ship structures it is desirable that tank arrangement is predetermined to obtain the minimum weight and then structural arrangement and scanting of each murder is determined to obtain the minimum weight within the given tank arrangement. To carry out the tank arrangement to give minimum weight a minimum weight design program which covers whole ship structures is developed by the combination of minimum weight design program of longitudinal members by classification rules and minimum weight design program of transverse members by generalized slope deflection method which were developed by the authors. The hullweight is estimated by summation of the weight of cargo hold part and the weight except cargo hold part which can be estimated by the empirical formula. In this study, the variation of hullweight is shown with the number of tank, the number of web and the location of longitudinal bulkhead. For the application of actual design alternative designs of tank arrangement which satisfy MARPOL regulation are determined. And several minimum weight designs of whole ship structures are carried out to obtain the tank arrangement which gives minimum weight and then the hullweight is compared with that of existing ship.