• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.3
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• pp.95-103
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• 2024

Recently, the aviation industry has experienced a significant surge in air traffic, and Incheon Airport is no exception. The Trombone STAR procedure, introduced in June 2021, needs to be managed efficiently to cope with the increased air traffic. This study aims to analyze the current STAR procedures at Incheon Airport, identify existing issues, and propose improvements to enhance efficiency. The study compares flight trajectories and fuel consumption based on real flight data from Korean Air B747 aircraft. The results suggest that optimized STAR procedures can contribute to better fuel management, reduced flight time, and decreased carbon emissions.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.1
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• pp.69-83
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• 1994

This paper deals with a capacitated ring-star network design problem (CRSNDP) with node capacity constraints. The CRSNDP is formulated as a mixed 0-1 integer problem, and a 2-phase heuristic solution procedure, ADD & VAM and RING, is developed, in which the CRSNDP is decomposed into two subproblems : the capacitated facility location problem (CFLP) and the traveling sales man problem (TSP). To solve the CFLP in phase I the ADD & VAM procedure selects hub nodes and their appropriate capacity from a candidate set and then assigns them user nodes under node capacity constraints. In phase II the RING procedure solves the TSP to interconnect the selected hubs to form a ring. Finally a solution of the CRSNDP can be achieved through combining two solution of phase I & II, thus a final design of the capacitated ring-star network is determined. The analysis of computational results on various random problems has shown that the 2-phase heuristic procedure produces a solution very fast even with large-scale problems.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.784-788
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• 1992

GSC ( Gold Star Cable Co, Ltd ) have developed Testing Equipment for high Voltaga Cable. The design concept and manufacture and Testing procedure are introduced in this paper.

• Journal of Astronomy and Space Sciences
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• v.12 no.2
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• pp.256-264
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• 1995

This report presents the development procedure and the results of a prototype star sensor which can be used as one of the attitude sensors of the KITSAT-3. The star sensor is a major attitude sensor that can determine the 3-axis attitude information, by comparing between star corrdinates in the star catalog and the measured corrdinates. The 2 dimensional CCD camera is used for measuring the star corrdinates and the DSP(Digital Signal Processor) technology is applied to the image and signal processing. Using the prototype star sensor with thermoelectri cooling technique, we have succesfully obtained the star images around 4th magnitude at Sobaeksan Astronomy Observatory minimizing night sky effect.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.598-600
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• 1993

Gold Star Cable Co. have developed Condenser Bushing Equipment for high voltage apparatus. The basic design theory and manufacture procedure are introduced in this paper.

• Journal of Arbitration Studies
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• v.27 no.4
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• pp.133-156
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• 2017

The purpose of this paper is to take a countermeasure of the investment treaty arbitration that Lone Star claimed to the Korean government. In particular, this study suggests procedural measures to be prepared by the Korean government after the arbitration award. The actual remedy in ICSID arbitration is the annulment procedure of arbitration award. Therefore, this study analyzed the measures that the Korean government can prepare based on the annulment grounds: the inadequacy of the constitution of the arbitral tribunal, the excessive power of the arbitrator, the corruption of the arbitrator, and the serious violation of the rules. First, the Korean government should decide whether to proceed with the annulment procedure after the arbitration award. Second, if they decide to do it, they should review the grounds of annulment. For example, it is possible to analyze whether the relationship between the arbitrator and Lone Star can be properly in the constitution of the arbitral tribunal, whether Lone Star is eligible to apply for ICSID arbitration, or whether arbitration tribunal ignores the crucial evidence that can affect the arbitration award. Independently, the Korean government needs to discuss the investment arbitration appeal system in a long-term perspective.

• Journal of Astronomy and Space Sciences
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• v.16 no.2
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• pp.273-284
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• 1999

In order to develop star trackers for a satellite in our country we studies selection procedure of optical parameters. For logical selection of the optical parameters, we simulated the entire processes in which star lights imaged on a CCD sensor were read into and processed in an associated electronics. The simulation resulted in relations between star's magnitude and achievable pointing accuracy, from which we derived optimal optical parameters to satisfy a required pointing accuracy of a star tracker. The selected optical parameters were used in an optical system design of a star tracker with a pointing accuracy of 10 arcsec.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.1
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• pp.13-27
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• 2014

In this paper, we deal with a Steiner Ring Star (SRS) problem arising from the design of survivable telecommunication networks. We develop two mixed integer programming formulations for the SRS problem by implementing Miller-Tucker-Zemlin (MTZ) and Sarin-Sherali-Bhootra (SSB) subtour elimination constraints, and then apply the reformulation-linearization technique (RLT) to enhance the lower bound obtained by the LP relaxation. By exploiting the ring-star structure of underlying network, we devise some valid inequalities that tighten the LP relaxation. Computational results demonstrate the effectiveness of the proposed solution procedure.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.775-778
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• 1992

In 1980, 154kV OF cable was installed at the Cheong-Pyeong pumped-storage power station. Effective head of this pumped-storage station is 250m between upper and lower re-servior and length of cable route is 750m. However, several failures have happened owing to steep slope during the operation. 154 kV XLPE cable was applied for this power station to eliminate a lack of stability on account of steep slope and successfully installed in 1991. Meanwhile, installation procedure brings about many problem to be solved. In this paper, we describe the counter measure of cable sliding phenomena caused by heat shrinkage as well as the method of installation of cable under the steep slope condition. And hereafter, we think this paper will be a good reference to design and installation of 154kV XLPE cables in steep slope turnnel at urban areas.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.4
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• pp.321-327
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• 2014

A wide scope of numerical simulations was performed to predict model-ship resistances by using STAR-CCM+ and OpenFOAM. The numerical results were compared with experimental measurements in towing tank to analyze statistical reliability of the present simulations. Based on the normal distribution of resistance errors in 113 cases of container carriers, tankers and very large crude-oil carriers, the confidence intervals of numerical error were estimated as [-2.64%,+2.32%] and [-1.82%, +1.87%] with 95% confidence in STAR-CCM+ and OpenFOAM, respectively. The resistance errors of liquefied natural gas carriers with single- and twin-skeg were confident in the ranges of [-2.51%,+2.64%] and [-2.29%, +1.46%], respectively. The grid uncertainty of resistance coefficients for KCS was also quantitatively analyzed by using a grid verification procedure. The grid uncertainty of OpenFOAM (5.1%) was larger than 4.4% uncertainty of STAR-CCM+ although OpenFOAM provided statistically more confident results than those of STAR-CCM+. It means that a grid system verified under a specific condition does not automatically lead to statistical reliability in general cases.