• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.425-427
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• 2000

We describe the preparation of a cobalt oxide in which the solid-pore architecture of the material is controllably varied. All $CoO_2$ gels derived from $CoCl_2$-based sol-gel synthesis, but exhibit markedly different final pore structures based on how the pore fluid is removed from forces that result from extraction are either low or nonexistent. These nanoscale mesoporous materials have higher $CoO_2$ crystallites. Controlling both the pore and solid architecture on the nanoscale offers a strategy for the design of new supercapacitor and charge-storage materials.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2271-2273
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• 1999

The manufacturing technology of XLPE power cable ( e.g. gas curing, triple common extrusion, clean room, super-clean compound, etc.) had been developed in 1960's and the design parameter of insulation thickness for EHV XLPE power cable at present was determined in 1960's. But, the quality of XLPE power cable has been improved up to now. The re-evaluation of design parameter for insulation thickness reductions is required and so we performed weibull plotting test using model cable. This paper describes the evaluation details of the insulation characteristics according to weibull plotting test.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1060-1062
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• 2003

In this study, an insulation design program which can calculate electric field of the GIS bus parts easily was developed. It also can evaluate the insulation safety depending on gas density. For bus parts of $1{\varphi}$ GIS, it was intended to provide a optimal diameter of a conductor and an enclosure automatically for the convenience of GIS insulation designer. This program was coded by Visual Basic and electric field was calculated by the Charge Simulation Method(CSM), which is one of the most accurate method for an electric field analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.265-274
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• 2017

This study presents a sustainable design method to optimize the embodied energy and $CO_2$ emission complying with the design code for reinforced concrete column. The sustainable design method effectively achieves the minimization of the environmental load and energy consumption whereas the conventional design method has been mostly focused on the cost saving. Failure of reinforced concrete column exhibits compressive or tensile failure mode against an external force such as flexure and compression; thus, optimization analyses are conducted for both failure modes. For the given sections and reinforcement ratios, the optimized sections are determined by optimizing cost, embodied energy, and $CO_2$ emission and various aspects of the sections are thoroughly investigated. The optimization analysis results show that 25% embodied energy and 55% $CO_2$ emission can be approximately reduced by 10% increase in cost. In particular, the embodied energy and $CO_2$ emission were more effectively reduced in the tensile failure mode rather than in the compressive failure mode. Consequently, it was proved that the sustainable design method effectively implements the concept of sustainable development in the design of reinforced concrete structure by optimizing embodied energy consumption and $CO_2$ emission.

• Journal of Ocean Engineering and Technology
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• v.32 no.1
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• pp.21-27
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• 2018

The design and analysis of a quayside mooring system for safe mooring of Prelude FLNG under extreme environmental conditions were carried out. The design of the mooring system considered the yard operation conditions and maximum wind speed during a typhoon. In order to secure the mooring safety of Prelude FLNG under an extreme environment, a special steel structure was designed between the quay and Prelude FLNG to maintain the distance from the quay to a certain extent to avoid a collision with the inclined base. The mooring safety was also ensured by installing additional new parts on the quay. A mooring analysis and mooring safety review were performed with more rigorous modeling considering the nonlinearity of the mooring rope and fender. In order to secure additional safety of the mooring system under extreme environmental conditions, a safety assessment was conducted on the failures of the mooring components proposed in the marine mooring guidelines. Based on the results of the mooring analysis, it was confirmed that the Prelude FLNG can be safely moored even under the extreme conditions of typhoons, and a worst case scenario analysis verified that the mooring system design was robust enough. The proposed mooring analysis and design method will provide a basis for the safe mooring of ultra-large floating offshore structures of similar size in the future.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.114-119
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• 2004

For passenger vessels, twin shaft types in propulsion system is generally adopted to provide a high-speed performance in low draught due to restricted operating condition in harbors or water channels. Struts of twin open shaft type support the shafts, bearings, and propellers. Therefore, strut design is needed to consider not only hydrodynamic performance but also structural and noise/vibration performance, In this paper, considerations in strut design at the initial design stage have been discussed based on existing references, numerical calculations, and their comparisons. Also, the strut design of a RoPax ferry has been carried out at the initial design stage, for an example.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.490-495
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• 2006

In this research, the design procedure and the design method of a single-phase line-start permanent magnet motor (LSPM) are proposed. In the design procedure, the permanent magnet is designed first and the windings and capacitors are designed later. As well, the points of design of each design parameter are explained. In the design of the single-phase LSPM, the equivalent circuit method is combined with the finite element method (FEM) because it has a shorter analysis time than FEM. The 400 watts single-phase LSPM is designed and manufactured. The characteristics of the manufactured single-phase LSPM are analyzed and experimented. From the analysis result and the experiment result, it is verified that the design procedure and the design method of the single-phase LSPM is valid.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.102-107
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• 2004

Performance based design is a recent evolutionary step in the process of designing fire protection systems. In essence, it is a logical design process resulting in a solution that achieves a specified performance. Sometimes the prescriptive solutions presented in various codes and standards are too expensive or inflexible. Often the solutions do not and enables optimization of a solution for cost and function. In this study, performance based design was carried out to determine the extent of passive fire protection for oil terminal facilities. The results of performance based design were compared with those of prescriptive code based design. Performance based design is not always more economic than prescriptive code based design but provides more reliable and effective design that is fit for the purpose.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2007.10a
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• pp.89-112
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• 2007

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.24-25
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• 2008

An Electrostatic discharge (ESD) protection has been a very important reliability issue in microelectronics, especially for RF (Radio Frequency) integrated circuits (ICs). This paper reviews design and analysis of on-chip ESD (electrostatic discharge) protection circuits for RF applications. Key issues in RF ESD protection, design methods, and RF ESD protection solutions are discussed.