• 보존과학회지
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• 제31권3호
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• pp.279-285
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• 2015

이 연구의 목적은 인천 옹진군 영흥도에서 발굴된 영흥도선 목부재 방사성탄소연대 분석을 통해 고선박의 연대를 규명하는 것이다. 중앙저판에서 10년 간격으로 채취된 5개의 연륜 블록에 대한 방사성탄소연대를 위글매치한 결과, 최외각 연륜의 ${\pm}2{\sigma}$ 연대(95.4% 신뢰구간)에서 A.D. 710~730년 또는 A.D. 750~774년으로 산출되어 이 고선박이 8세기 초반 또는 중반에 제작된 것을 알 수 있었다. 이 연대는 선박의 구조와 도기의 양식으로 추론된 고고학적 편년과 일치되는 결과이다.

• 대한조선학회 특별논문집
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• 대한조선학회 2009년도 특별논문집
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• pp.107-114
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• 2009

In the recent large block are used to build the ship to improve productivity. For this reason, two or more floating cranes that are connected in parallel is the trend. Typically, when working with floating crane load safety factor is considered. Even in the parallel operation, load safety factor is calculated similar to working alone. For this reason, operations do not guarantee the reliability or excessive safety factor applied. Therefore, the subdivided cases for calculating the safety factor are defined when parallel connected floating cranes are operated. Based on those cases, the operation standard is made about procedure using parallel connected floating cranes. And to verify this, dynamics simulation was performed for verification using the dynamics simulation program.

• Journal of Advanced Research in Ocean Engineering
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• 제1권2호
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• pp.106-114
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• 2015

In the fabrication of offshore oil and gas facilities, the significance of dimension control is growing continuously. But, it is difficult to determine the deformation of the structure during fabrication by simple lab tests due to the large size and the complicated shape. Strain-boundary method (a kind of shrinkage method) based on the shell element was proposed to predict the welding distortion of a structure effectively. Modeling of weld geometry in shell element is still a difficult task. In this paper, a concept of imaginary temperature pair is introduced to handle the effect of geometric factors such as groove shape, plate thickness and pass number, etc. Single pass imaginary temperature pair formula is derived from the relation between the groove area and the FE mesh size. By considering the contribution of each weld layer to the whole weldment, multi-pass imaginary temperature is also derived. Since the temperature difference represents the distortion increment, cumulative distortion curve can be drawn by integrating the temperature difference. This curve will be a useful solution when engineers meet some problems occurred in the shipyard. A typical example is shown about utilization of this curve. Several verifications are conducted to examine the validity of the proposed methodology. The applicability of the model is also demonstrated by applying it to the fabrication process of the heavy ship block. It is expected that the imaginary temperature model can effectively solve the modeling problem in shell element. It is also expected that the cumulative distortion curve derived from the imaginary temperature can offer useful qualitative information about angular distortion without FE analysis.

• 한국항해항만학회지
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• 제28권10호
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• pp.891-897
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• 2004

본 연구에서는 수직블록배치형태를 가지는 자동화 컨테이너 터미널을 대상으로 안벽과 야드의 연계작업을 수행하는 이송장비에 대한 시뮬레이션 모델을 수립하였다. 일반적으로 컨테이너 터미널은 안벽장비의 생산성으로 효율성이 평가되며, 안벽장비의 생산성을 최대화하기 위해서는 이송장비와 야드장비의 원활한 지원이 이루어져야 한다. 이중 이송장비는 안벽장비와 직접적으로 연계작업을 수행하므로 안벽장비의 생산성에 많은 영향을 미치는 요소이며, 운행대수와 주행방식에 따라 작업성능 또한 매우 달라지게 된다. 따라서, 본 연구에서는 이송장비의 작업생산성을 평가할 수 있는 시뮬레이션 모델을 개발하였으며, 수립된 모델을 통해 가상의 환경에서 다양한 이송장비의 운영에 따른 안벽장비의 생산성을 분석해 보았다.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.35-41
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• 2013

Nowadays, automated modeling system for steel margin based on interactive user interface has been developed and applied to the production design stage. The system could increase design efficiency and minimize human error owing to recent CAD technique. However, there has been no approach to the pre-nesting design stage at all in early modeling process especially where ship model should be handled at more than two design stages using AVEVA Marine. A designer of the design stage needs artificial intelligence system beyond modeling automation when 3D model must be prepared in early modeling process using AVEVA Marine because they have focused on 2D nesting traditionally. In addition, they have a hard time figuring out the model prepared in previous design stage and modifying the model for steel purchase size in early modeling process. In this paper, artificial intelligence modeling system for automated application of steel margin in early modeling process using AVEVA Marine is developed in order to apply to the pre-nesting design stage that can detect effective segments before a calculation to find if a segment locates near block butt boundaries by filtering noise segments among lines, curves and surface intersections based on IT big data analysis.

• 대한조선학회논문집
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• 제47권2호
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• pp.113-121
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• 2010

Recently, as container ships become larger and faster, rudder cavitations are more frequently observed near the gap between the horn and rudder plates of the ships to cause serious damages to the rudder surface of the ship. The authors already have suggested through a series of model experiments and numerical computations that employment of an appropriate blocking device for gap flow may retard the gap cavitation. For examples, a cam device installed near the outer edges of the vertical gap or a water-injection device combined with a pair of half-round bars installed inside the gap can considerably reduce the gap cavitation. However, it is also found that effective blocking of the flow through the vertical gap results in growth of the cavitation near the horizontal gap instead. In the present study, effectiveness of the simultaneous blocking of the flow through the horizontal and vertical gaps of a horn type rudder in minimizing the damage by gap cavitation is studied. Additional blocking disks are inserted inside the horizontal gaps on the top and bottom of the pintle block and numerical computations are carried out to confirm the combined effect of the blocking devices.

• 한국수산과학회지
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• 제36권6호
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• pp.743-748
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• 2003

An oil boom was set up in order to contain diffused oil from spills and for the retrenchment of damage caused by oil Pollution. Therefore, the oil boom anchor needed proper holding power to endure high resistance from flowing streams and to secure the oil boom around the spill, and must dredge directly into the seabed when it is dropped and block oil outflow immediately. This study investigated the holding power of the danforth anchor and the coastal fishing vessel anchor used for oil booms in the KMPRC (Korea Marine Pollution Response Corporation). For each type, a 30 kg and 20 kg anchor were used. The holding power of the danforth anchors were measured by dropping both weights 10 times. However the coastal fishing vessel anchors were dropped only 5 times each, because no substantial differences were found between drops. In the results of the danforth anchors, an anchor awoke occurred in 2 drops of the 30 kg anchor and in 4 drops of the 20 kg anchor, wherein there was no holding power to be measured. With exception to the anchor awoke cases, the maximum holding power of the danforth 30 kg and 20 kg anchors was 250-520 kg and 123-233 kg, respectively. In the case of the coastal fishing vessel anchors of 30 kg and 20 kg, throughout the experiment, there was no occurrence of an anchor awoke. For the 30 kg and 20 kg anchors, the maximum holding power was measured to be 209-230 kg and 155-170 kg, respectively. Therefore, the holding power of the coastal fishing vessel anchor was shown to be much poorer than that of the danforth anchor. However, the holding power of the danforth anchor was very unstable. Due to the occurrences of anchor awoke, there was no holding power and the measurement value of maximum holding power showed too much variation among the drop tests. Also, after the maximum holding power was achieved, anchor awoke occurred easily. In the case of the coastal fishing vessel anchor was much more stabile, because there was no anchor awoke and no instance where holding power failed. Also the maximum holding power was reached quickly and almost no variation occurred among the drop tests.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.941-944
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• 2015

본 논문에서는 여러 대역의 주파수를 하나의 모듈로 통합하여 선박이 해외 각국에서도 하나의 위성안테나로 사용할 수 있는 다중대역 FEM(Front-End Module)모듈을 설계하였다. 설계된 FEM은 다중대역 저잡음 수신 증폭회로, 주파수 변환 회로, IF 증폭회로, 전압 제어 발진기(VCO : Voltage Control Oscillator)를 이용한 신호발생회로 네 가지 회로로 구성하였다. 다중대역 2.05GHz대역을 변환하기 위하여 4개(대역1, 대역2, 대역3, 대역4)의 국부 발진 신호를 생성하여 4개의 IF신호를 출력하도록 설계하였으며 개발된 변환 장치는 변환이득 64dB, 잡음지수 1dB 이하, 출력 P1dB 15dBm 이상, 위상잡음은 -73dBc@0.1KHz를 나타내었다.

• 플랜트 저널
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• 제13권2호
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• pp.39-45
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• 2017

본 논문은 시스템엔지니어링기법을 이용하여 해양플랜트 산업의 소형 유틸리티 장비의 입찰단계에서 사용가능한 FEED 검증 수행모델에 대한 연구이다. 현재 국내 해양플랜트 기자재산업계는 해양플랜트에 진출하면서 프로젝트 수행에 따른 재정적 위험에 직면한 상태이며, 그 주요한 원인으로 기자재업체의 발주처(COMPANY 또는 EPC: Engineering, Procurement and Construction) 로부터 제공받은 FEED 결과물에 대한 검증능력부족으로 조사되었다. 이에 요구사항 분석, 기능, 성능분석 및 물리적아키텍처 구축프로세스를 순차적으로 적용하는 시스템 엔지니어링 기법을 간략화 한 FEED 설계 검증방법을 제안하고 이를 소형 유틸리티 장비(Air Compressor)를 대상으로 기존의 경험에 의존한 검증방법과 개발한 FEED 검증 모델을 적용한 결과를 비교함으로써 개발된 모델의 사용적정성을 검증하였다.

• 대한조선학회논문집
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• 제58권5호
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• pp.303-313
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• 2021

Recently, quality control of the Liquefied Natural Gas Carrier (LNGC) cargo hold and block-erection interference areas using 3D scanners have been performed, focusing on large shipyards and the international association of classification societies. In this study, as a part of the research on LNGC cargo hold quality management advancement, a study on deep-learning-based scaffolding system 3D point cloud object detection and post-processing were conducted using a LNGC cargo hold 3D point cloud. The scaffolding system point cloud object detection is based on the PointNet deep learning architecture that detects objects using point clouds, achieving 70% prediction accuracy. In addition, the possibility of improving the accuracy of object detection through parameter adjustment is confirmed, and the standard of Intersection over Union (IoU), an index for determining whether the object is the same, is achieved. To avoid the manual post-processing work, the object detection architecture allows automatic task performance and can achieve stable prediction accuracy through supplementation and improvement of learning data. In the future, an improved study will be conducted on not only the flat surface of the LNGC cargo hold but also complex systems such as curved surfaces, and the results are expected to be applicable in process progress automation rate monitoring and ship quality control.