• 한국해양공학회지
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• 제25권5호
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• pp.64-68
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• 2011

The motion responses of a 5-MW floating offshore wind turbine were simulated in regular and irregular waves and its RAOs and significant motion responses were calculated, respectively. The floating offshore wind turbine employed in this simulation was the OC3-Hywind designed by the National Renewable Research Laboratory, USA. The numerical simulation was carried out using MOSES (Multi-Operational Structural Engineering Simulator), which is widely used to analyze and design floating offshore structures in the gas and oil industry.

• 전자통신동향분석
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• 제33권6호
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• pp.1-11
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• 2018

Several industrial applications such as space exploration, aerospace, automotive, the downhole oil and gas industry, and geothermal power plants require specific electronic systems under extremely high temperatures. For the majority of such applications, silicon-based technologies (bulk silicon, silicon-on-insulator) are limited by their maximum operating temperature. Silicon carbide (SiC) has been recognized as one of the prime candidates for providing the desired semiconductor in extremely high-temperature applications. In addition, it has become particularly interesting owing to a Si-compatible process technology for dedicated devices and integrated circuits. This paper briefly introduces a variety of SiC-based integrated circuits for use under extremely high temperatures and covers the technology trend of SiC CMOS devices and processes including the useful implementation of SiC ICs.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1000-1014
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• 2009

Research sponsored by the Korean Government investigated the establishment of a risk management process by Korean contractors involved with plant projects in the Middle East. This research effort builds upon the work completed by the Construction Industry Institute (CII), called the International Project Risk Assessment (IPRA) tool and method, and also explored how CII's Project Definition Rating Index (PDRI) could be incorporated to improve project planning by addressing risks and scope development issues. Specific findings and recommendations were developed including the creation of the Contractor Critical Areas of Concern (CCAC) risk screening tool for Korean contractors pursuing Middle East oil and gas projects.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.97-102
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• 2013

As the offshore oil and gas upstream industry moves into deeper water, the FPSOs are the cost-effective solution. In the harsh environment such as in North Sea, station keeping and heading control capability obtained through the DP and Position Mooring (DPM) system of FPSOs play important roles to keep the safety. This paper introduces the concept, function and sub-system of the DPM systems which has been applied for the North Sea FPSOs since the late 1980s. The requirements and guidelines of some internationally recognized standards are also described, which are important to build the design basis at the early phases of the project.

• 조명전기설비학회논문지
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• 제23권11호
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• pp.34-43
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• 2009

SCADA (Supervisory Control and Data Acquisition) system has been used for remote measurement and control on the critical infrastructures as well as modem industrial facilities. As cyber attacks increase on communication networks, SCADA network has been also exposed to cyber security problems. Especially, SCADA systems of energy industry such as electric power, gas and oil are vulnerable to targeted cyber attack and terrorism Recently, many research efforts to solve the problems have made progress on SCADA network security. In this paper, flexible key distribution concept is proposed for improving the security of SCADA network using Multiagent System (MAS).

• Journal of international Conference on Electrical Machines and Systems
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• 제1권4호
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• pp.419-424
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• 2012

This paper presents a tubular reciprocating translational motion permanent magnet synchronous motor for percussive drilling applications for offshore oil & gas industry. The motor model and rock model are built up by doing force analysis of the motor and analyzing the physical procesof impact. The optimization of input voltage waveforms to maximize the rate of penetration is done by simulations. The simulation results show that the motor can be utilized in percussive drilling applications and achieve a very large impact force. Simulation results for optimization also show that second harmonic input voltage produces a higher rate of penetration than the sine wave and fourth harmonic input voltages.

• International Journal of Fluid Machinery and Systems
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• 제8권1호
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• pp.36-45
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• 2015

Oil and gas industry pumps viscous fluids and investigation of flow physics is important to understand the machine behavior to deliver such fluids. 3D numerical flow simulation and analysis for different viscous fluids at different rotational speeds of a centrifugal impeller have been reported in this paper. Reynolds-averaged Navier Stokes (RANS) equations were solved and the performance analysis was made. Standard two equation k-${\varepsilon}$ model was used for the turbulence closure of steady incompressible flow. An inlet recirculation and reverse flow in impeller passage was observed at low impeller speeds. It was also found that the higher viscosity fluids have higher recirculation which hinders the impeller performance.

• 방사성폐기물학회지
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• 제21권2호
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• pp.295-301
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• 2023

To broaden the utilization of nuclear energy, uranium as a fuel should be mined indispensably. Mining accounts for the largest portion of the cost of producing the uranium assembly. Therefore, this study analyzes the trends of uranium prices, which have a significant impacts on the mining cost. Uranium production contributing to the price fluctuations is explained in five periods from 1945 to the present. Moreover, the series of events affecting uranium prices from the 1970s until the present are verified. Among them, the most recent incidents considered in this study are the following: COVID-19 pandemic, Kazakhstan unrest, and Russia-Ukraine war. European countries have started to reconsider the transition to nuclear power to reduce their dependence on Russian oil and gas, which has contributed to the surge in uranium prices. Based on the results of this study, various international issues have been closely associated with the nuclear power industry and uranium, affecting the production of uranium and its price.

• Corrosion Science and Technology
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• 제14권2호
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• pp.54-58
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• 2015

A heavy oil of low quality has been mainly used in the diesel engine of the merchant ship as the oil price has been significantly jumped for several years. Thus, a combustion chamber of the engine has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas of the combustion chamber has been getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of the engine parts such as exhaust valve, piston crown and cylinder head surrounded with combustion chamber are more serious compared to the other parts of the engine. Therefore, an optimum repair welding for these engine parts is very important to prolong their lifetime in a economical point of view. In this study, 1.25Cr-0.5Mo filler metal was welded with SMAW method in the forged steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected and base metal zones were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. The weld metal and base metal zones exhibited the highest and lowest values of hardness respectively. And, the corrosion resistance of the heat affected and weld metal zones was also increased than that of the base metal zone. Furthermore, it appeared that the corrosive products with red color and local corrosion like as a pitting corrosion were more frequently observed on the surface of the base metal zone compared to the heat affected and weld metal zones. Consequently, it is suggested that the mechanical and corrosion characteristics of the piston crown can be predominantly improved by repair welding method using the 1.25Cr-0.5Mo electrode.

• 자원환경지질
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• 제47권3호
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• pp.291-302
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• 2014

중국 정부와 산하기관들은 자국의 불안정한 자원수급을 위해 노력하고 있다. 중국 국토자원부(MNR)는 광물에너지자원 잠재력과 가채매장량 평가를 위해 중국 국토자원규획(1999~2010), 중국 광산자원조사규획(2008~2020), 중국 셰일가스산업정책 공고(2013), 중국 셰일가스 자원평가 및 우선 개발지역 선정 프로젝트(2012), 중국 셰일가스 개발규획(2011~2015) 등과 같은 국가 차원의 시책을 시행하였다. 중국의 셰일가스 자원은 국가 매장량의 대부분으로 평가된 우수한 잠재력을 가진 쓰촨분지와 타림분지, 2개의 거대 퇴적분지는 있는데, 이미 전 국토에 걸쳐 셰일가스 가채 매장량이 광범위하게 분포하는 것으로 조사되었다. 중국의 셰일가스 가채 매장량 규모는 31조 $m^3$(1,115조 cubic feet) 정도로 평가되고 있으며, 중국의 미국, 캐나다와 함께 세계 3대 셰일가스 상업생산이 가능한 국가 중의 하나이다. 지금 중국은 셰일가스의 상업생산을 증진하기 위한 기술개발과 가채 매장량의 확충을 위한 조사 탐사활동에 매진하고 있다. 중국의 이러한 정책과 개발 관련 기술분석을 토대로 할 때, 우리는 국제 유가시장 변동 등에 따른 중국의 셰일가스 개발과 R&D 동향을 적극적으로 모니터링 되어야 한다고 사료된다.