• Journal of the Society of Naval Architects of Korea
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• v.56 no.1
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• pp.47-57
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• 2019

Recent CFD solvers in engineering have to treat geometrically complex domains and moving body problems. In ship hydrodynamics, flow around the stern and ship motions in waves are examples of such cases mentioned before. The unstructured grid scheme is successfully applied for these problems, but it has weakness of inefficient memory usage and intensive computational time as compared to the structured grid method. Overset grid scheme is one of the alternatives for structured grid system taking advantage of fast and memory efficiency. Overset grid scheme is especially useful for moving body problem because there is no need to re-mesh around the body. In this paper, we adopted the Suggar++, the grid connectivity and interpolation utility for the overlapping grid, to WAVIS which is the in-house flow solver of KRISO. Then we introduced some applications using the overset grid method for flow analysis around the ships. The computed results show that WAVIS with Suggar++ is practically feasible and has an advantages for moving geometry cases.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.499-505
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• 1998

The purpose of this study was to ivestigate the structural characteristics of waste soulble browning reaction prodcuts (WS-BRPs) isolated from Korean red ginseng. They all showed the maximum absorbances at near 280 nm. Their IR spectra suggested the presence of hydroxyl, amide carbonyl and aliphatic methine groups. From sugar analysis it was identified that L and S-1 contained two kinds of suggar, glucose and xylose, and S-2, a fructose together with glucose and xylose. Thirteen different amino acids were identified in L. Ten amino acids from S-1 and seven amino acids from S-2 were identified using Auto Amino Acid Analyzer. Glycine, serine and glutamic acid in S-1 and one unknown amino acid and glycine in S-2 were detected as the major amino acids, respectively. From the 1H-and 13C-NMR spectra, it was identified that a number of sugar moieties, carbonyl and carbon double bonds (only in S-2) were contained in the three WS-BRP components. Approximate number of sugar moiety of L, S-1 and S-2 was determined to be 8∼10, 9∼11 and 4∼5, respectively. Contents of nitrogen, carbon and hydrogen showed L>S-1>S-2.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.385-393
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• 2018

In this study, the analysis of 2DOF (2 Degree Of Freedom) motion and added resistance of a ship in regular head waves is carried out using RANS (Reynolds Averaged Navier-Stokes) approach. In order to improve the accuracy for large amplitude motions, the dynamic overset scheme is adopted. One of the dynamic overset schemes, Suggar++ is applied to WAVIS which is the in-house RANS code of KRISO (Korea Research Institute of Ships and Ocean Engineering). The grid convergence test is carried out using the present scheme before the analysis. The target hull form is KRISO VLCC tanker (KVLCC2) and 13 wave length conditions are applied. The present scheme shows the improved results comparing with the results of WAVIS2 in the non-inertial reference frame. The dynamic overset scheme is confirmed to give the comparatively better results for the large amplitude motion cases than the non-inertial frame based scheme.