• Transactions of Materials Processing
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• v.17 no.7
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• pp.491-495
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• 2008

Incremental forming path to manufacture a thick concave steel plate using the line array roll set is designed. To find the optimum forming path, the forming processes are simulated by the finite element method. A general-purpose commercial software, MSC MARC is used. A modeling with 8-node hexahedral elastic-plastic solid is performed to predict accurate springback and the analysis process was composed of 18 passes. The proposed forming paths are verified through experiments carried out in the prototype line array roll set. It is found that the process can be successfully applied to the fabrication of the dual curvature ship hull plate.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.1 s.151
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• pp.48-54
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• 2007

Higher productivity and less cost during the manufacturing process of ships are required to maintain international competitiveness of modern shipbuilding industries. The integrated hull/ outfitting/ painting scheduling(IHOP) process is a final point, where logistics are finally being integrated and upcoming schedules are made. Therefore, more profits are expected from IHOP by effective management. In this thesis, IHOP is proposed in order to solve how to choose block erection date with IHOP scheduling logic. The result of IHOP scheduling is highly advised to utilize fabrication, outfitting shops. A standardized operation and load of resource will eventually be applied in long-term time span point of view for this will make it easy to enable capacity planning and workforce planning. It is also expected to eliminate inefficiency in overtime work and efficiently utilize manpower in short-term.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.127-133
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• 2011

The following Technology Report was written with respect to recent offshore technology development. This report was prepared with the purpose of suggesting recent offshore technology and upcoming visions by describing the principles of an offshore drilling operation, the NL Tensioner Cylinder Package R & D, and the general technology related to three offshore patent areas, as major contents.

• Journal of the Korean Institute of Navigation
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• v.21 no.2
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• pp.59-67
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• 1997

This paper describe the method and the result of making a fiber optic gyrocompass measuring the heading angles of a ship with a fiber optic sensor. As the method seeking for the heading angles, it is possible to get the heading angles by measuring the output signals from a stationary fiber optic sensor in at least three directions such as a heading direction and other two directions having phase difference ${\phi}1$ and ${\phi}2$ to the heading. We made the static fiber optic gyrocompass by a high performance fiber optic sensor having scale factor of 210mV/deg/s and resolution of 0.5deg/hr using this principle. The accuracy of this system was $0.29^{\circ}$ from 20 numbers of data measuring the arbitrary heading angle.

• Journal of Welding and Joining
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• v.12 no.4
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• pp.151-161
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• 1994

FCAW has wide application in ship fabrication, maintenance and field erection. It has many advantages over SMAW.SAW and GMAW process. In many applications, the FCAW provides highquality weld metal. This method can reduce weld defects especially porosity and spatter. But the fatigue characteristics of those deposited metal have been rarely investigated. The purpose of this study is to investigate the cyclic stress-strain behavior and fatigue tests by the constant strain control were carried out on the rounded smooth specimen with deposited metal using the metal type flux cored wire. As the results of this study for the deposited metal welded by the metal type flux cored wire, the hardening or softening characteristics under cyclic load were investigated and cyclic stress-strain curve, strain-fatigue life curve, stress-strain function and fatigue life relation which are useful to estimate the fatigue life under the stress concentration condition were obtained.

• Corrosion Science and Technology
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• v.6 no.2
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• pp.74-76
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• 2007

The increasing interest in the corrosion properties of weld joints in the corrosive environment is placing stringent demands on the manufacturing techniques and performance requirements, and the manufacture employs the high quality and efficiency welding process to produce welds. Welding plays an important role in the fabrication of chemical plants, nuclear power plant, ship construction, and this has led to an increasing attention to the corrosion resistant weld joints. This paper covers a recent technical trends of welding technologies for corrosion resistance properties including the COMPENDEX DB analysis of welding materials, welding process, and welding fabrications.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.361-364
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• 2008

Incremental forming path to manufacture a thick concave steel plate using the line array roll set is designed. To find the optimum forming path, the forming processes are simulated by the finite element method. A general-purpose commercial software, MSC.MARC is used. The rolls are modeled as rigid surfaces and the thick plate is modeled as 8-node hexahedral elastic-plastic solid elements to predict accurate springback. It is found that the process can be successfully applied to the fabrication of the dual curvature ship hull plate

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.123-131
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• 2020

The system performance of naval multi function radar is affected by radar beam operation. Multi f function radar has to operate complicated beam better than search radar and tracking radar which have single operation. This paper describes fabricating analysis tool for the verification method for system performance of naval multi function radar. We composed the model that naval ship with MFR and radar which are detecting targets to verification the system performance. The targets are composed anti-aircraft and anti-ship. We integrate each model and make naval MFR simulator that applied resource management of track beam and search beam. We verify analysis tool by simulation in operating scenario after adjusting system parameter to analysis tool.

• Corrosion Science and Technology
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• v.6 no.5
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• pp.219-226
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• 2007

Pre-construction primer (PCP), or shopprimer, have been applied to steel plates to control temporary corrosion during ship fabrication. For surface preparation at ship block stage, in common shipyard practices, welding beads, burnt and rusted areas shall be blasted or power tool cleaned and the contamination such as zinc salt shall be removed with blasting or power tool. Whereas, the sound film of PCP needs not to be removed or roughened as the paint having good compatibility with PCP is used for the first coat. In many cases, however, full blasting or sweep blasting on the sound PCP treated block assemblies was requested. There still has been argument about the legitimacy of this practice, thus, it is critical to evaluate the quality of the coating system applied on the sound PCP retained condition, comparing with the one applied on the full blasted or sweep blasted condition. In this study, two different epoxy systems for water ballast tank were applied on the surfaces with sound PCP condition, full blasted condition, and sweep blasted condition. Coating performances such as durability, anti-corrosion, cathodic disbondment resistance were evaluated. The test results clearly indicated that the sound film of PCP needed not to be removed or roughened as the paint having good compatibility with PCP based on inorganic zinc silicate.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.4
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• pp.306-315
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• 2005

The distribution and composition of marine floating debris were recorded from a training ship 'Kyeongyang' of Gangwon Provincial University at May 19-29, 2004 and Aug.24-31, 2004. The sampled area is the middle part of East Sea of Korea(the coast of Gangwondo and region of Ulleung island and Tokdo), divided into 27 unit segments on survey areas. Debris fabrication materials were categorized with 6 items using the following; styrofoam, paper & cardboard, net & rope, vinyl & plastic, floating metal & glass, man-made or natural wood. From the investigation on May,2004, total numbers of marine floating debris in the middle part of the East Sea of Korea was 996 individuals. The No. 1 and No. 2 unit segment located at south-west region of Ulleung Island showed higher density than others. The styrofoam and vinyl & plastic accounted for 72.8% of all debris fabrication materials. From the investigation on August, 2004, total numbers of marine floating debris in the coast of the Gangwondo of Korea was 2,473 individuals. The No. 13 and No. 14 unit segment located at the vicinity of Samcheok showed higher density than others. The styrofoam and vinyl & plastic amounted to 76.1%. In the coast of the Gangwondo, the vinyl & plastic showed the highest density of 6 items were 41.3% and 68.0% on May and August, respectively. The total numbers of marine floating debris on May and August were 3,399 individuals. Vinyl & plastic accounted for 59.4%(2,019 ind.) among all debris, next styrofoam 15.8%(537 ind.) and wood 11.2%(379 ind.).