• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.2
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• pp.89-100
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• 2002

In this paper, we propose a group key management architecture for the secure group communications in mobile netwowrks and authenticated key agreement protocol for this system. Most of existing group key management schemes un certificates based on the public key for the purpose of user authentication and key agreement in secure fashion however, we use the ICPK(Implicitly Certified Public key) to reduce the bandwidth for a certificate exchanging and to improve a computational efficiency. In this architecture, we use two-tier approach to deal with key management where the whole group is divided into two parts; the first is a cell groups consisted of mobile hosts and another is a control group consisted of cell group managers. This approach can provide flexibility of key management such that the affection for a membership change is locally restricted to the cell group which is an autonomous area of the CGM(Cell Group Manager).

• Journal of Digital Contents Society
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• v.7 no.4
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• pp.263-269
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• 2006

The trend of the web is moving from portal-centered to user-centered, and RIA(rich internet application) is considered best solution for usability and functionality of the next generation web. But the lack of reference document or technical guide for RIA implementation is a big obstacle for extension of RIA environment to practical business engineer or user. In this paper, I will suggest the implementation conceptand reference site for user-centered environment based on RIA concept. The suggested concept support wire/wireless environment, and use the e-mail that is already used by many company or portal. The contents of this paper will be very helpful to the practical engineer or portal/company that want to use or implement about RIA environment.

• Journal of Korea Water Resources Association
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• v.37 no.3
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• pp.173-184
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• 2004

The objective of this study is to examine the usefulness of climate model simulations (GCM) in Korea water resource management. The methods are based on probabilistic measures of the effectiveness of GCM simulations of an indicator variable for discriminating high versus low regional observations of a target variable. The formulation uses the significance probability of the Kolmogorov-Smirnov test for detecting differences between two variables. AMIP-II(Atmospheric Model Intercomparison Project-II) type GCM simulation done by ECMWF(European Centre for Medium-Range Weather Forecasts) was used for indicator variable and observed mean average precipitation(MAP) values on 7 major river basins were used as target variable. Monte Carlo simulation is used to establish the significance of the estimator values. The results show that GCM simulations done by ECMWF are skillful in discriminating the high from the low of the observed MAP for wet season in all seven basins of Korea, but not enough for dry season.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.5-13
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• 2012

This research have investigated the application and the injection effect of the alkaline silicasol grouting materia (which is) recently developed. To compare the engineering characteristics of the alkaline silicasol which is formed with 3D-gel and the sodium silicate, it have studied the strength and environmental effects through the laboratory test, and field application was investigated with a review of the injection effect and waterproof through the field test. As a result of the laboratory test, unconfined compression strength of alkaline silicasol was 5 times more than sodium silicate. As a result of the leaching test, a total amount of the eluviated elements was very small, it considered the environment-friendly material. As a result of the field test, considerable reduction of the coefficient of permeability at the hydraulic layer was confirmed, and it could secure that the coefficient of permeability showed a lower than standard value of $10^{-5}cm/sec$.

• Journal of the Korean Geophysical Society
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• v.9 no.2
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• pp.135-145
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• 2006

The surface temperature and hydrological budget for the last glacial maximum (LGM) is simulatedwith an atmospheric general circulation model of NCAR CCM3 at spectral truncation of T170, corespondingto a grid cel size of roughly 75 km. LGM simulations were forced with the reconstructed CLIMAP sea surface temperatures, sea ice distribution, ice sheet topography, reduced CO2, and orbital parameters.oC in winter, 5.6oC in sumer,and 6oC annual-mean. The decrease of surface temperature leads to a weakening of the hydrologicalcycle. Global-mean precipitation decreases by about 14% in winter, 17% in summer, and 13% annually.However, some regions such as the U.S., southern Europe, northern and eastern Africa, and the SouthAmerica appear to be weter in the LGM winter and Canada and the Midle East are weter in sumer. model captures detailed climate features over land.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.48.4-48.4
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• 2019

We studied the metal-distribution of isolated Milky-way mass galaxy using various hydrodynamic solvers and investigated the difference of the result between AMR and SPH codes. In particle-based codes, physical quantities like mass or metallicity defined in each particle are conserved unless being injected explicitly by the effect of the supernova, whereas in the Eulerian codes the diffusion is simply accomplished by hydro-equation. Therefore, without including explicit physics of diffusion on the SPH- codes, the metal mixing in the galaxy or CGM only can be accomplished by the direct motion of the particles, however, the standard-SPH codes depress the instability of the turbulent fluid mixing. In this work, we simulated under common initial conditions, common gas-physics like cooling-heating models, and star-formation feedback using ENZO(AMR) GIZMO and GADGET-2 codes. We additionally included a metal-diffusion algorithm on the SPH-codes, which follows the subgrid-turbulent mixing model investigated by Shen et al. (2010) and compared the effect of the metal-outflow on the halo region of the galaxy in different hydro-solvers. We also found that for the implementation of the diffusion scheme in the SPH-codes, the existence of a sufficient number of the gas-particles, which is the carrier of the metals, is necessary. So we tested a new initial condition for proper implementation of the diffusion scheme on the SPH simulations. By comparing the metal-contamination of the circumgalactic medium with different hydrodynamics models, we quantify the diffusion strength of AMR codes using diffusion parameterization of the SPH codes and also suggest the calibration solutions in the different behavior of codes in metal-outflow.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.586-594
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• 1996

This study was designed to determine the level of soybean meal (SM) that could be substituted for fish meal in the diet for Korean rockfish (Sebastes schlegeli). A control diet with white fish meal as only protein source was included, SM was substituted at levels of $5\%,\;10\%,\;15\%,\;and\;20\%$ for portions of the fish meal in the diet. Amino acids (met+lys) supplementation and two different SM particle sizes (0.5 mm and 0.25 mm) in the $20\%$ SM diet were compared. In addition, combination of $10\%$ SM, $10\%$ corn gluten meal (CGM) and $10\%$ meat and bone meal (MBM) was substituted for the fish meal in the diet. Duplicate groups of the 30 fish averaging 22.9 g were fed one of 8 isoproteic $(48\%)$and isolipidic $(7.5\%)$ experimental diets to satiation twice a day for 9 weeks. No significant differences were found among fish fed the control, substituting up to $20\%\;SM,\;20\%$ SM containing amino acids, and $10\%\;SM+10\%\;CGM+10\%$ MBM diets in weight gain, feed efficiency, daily feed intake, and protein retention (P>0.05). Feed efficiency, daily feed intake and protein retention in fish fed the diet containing $20\%$ SM with 0.5 mm particle size were not significantly different to those in fish fed the diets containing less than $20\%\;SM\;(P>0.05)$, however, weight gain was significantly lower than that of the control and $5\%\;SM\;diets\;(P<0.05)$. It is concluded that SM ran be used as a partial substitute for fish meal up to $20\%$ in the diet, and that the inclusion of SM with an adequate combination of several protein sources can replace larger amounts of fish meal in the diet.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.887-896
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• 2004

The present study was carried out to investigate the blood markers of Mongolian horses. The blood redcell types and blood protein types(biochemical polymorphisrns) were tested from 19 Mongolian horses by serological and electrophoretic procedure, and their phenotypes and gene frequencies were estimated. The blood group and biochemical polymorphism phenotypes observed with high frequency were $A^{af}$(42.1%), $C^a$(89.5%), $K^-$(84.2%), $U^a$(63.2%), $P^a$(42.1%) $P^-$42.1%), $Q^c$(31.6%) $Q^-$(31.6%), $AL^{AB}$((52.6%), AI$B^K$(89.5%), $ES^1$(63.2%), $GC^F$(78.9%), $HB^BI$1(68.4%), PG$D^F$(84.2%), $TF^{FIR}$(21.1%), $TF^{F2R}$(21.1%)(21.1%), and genotypes $D^{cgm/dghm}$(15.8%), $D^{dghm/dghm}$(15.8%), $D^{ad/dghm}$(10.5%), $D^{ade/dghm}$(10.5%), in Mongolian horses, respectively. Alleles observed with high frequency were $A^a$(0.4211), $C^a$(0.8947), $K^-$(0.8421), $U^a$(0.6316), $P^a$(0.4474), $Q^c$(0.4474), $D^{dghm}$(0.4211), $AL^B$(0.6579), $AIB^K$(0.9211), $ES^I$(0.7895), $GC^F$(0.8947), $HB^{BI}$(0.7895), $PGD^F$(0.8421) and $TF^R$(0.3421) in Mongolian horses. These results present basic information for estimating the genetic relationships between the Korean native horse, and developing a system for parentage verification and individuals identification in Mongolian horse.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.533-540
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• 2006

This experiment was conducted to determine crude protein requirements for maintenance (CPm) of growing Hanwoo steers. Eighteen Hanwoo steers (173.7kg) were allocated randomly to diets with three levels of crude protein in the concentrate by replacing ground corn with corn gluten meal: 0% (LCP), 7.2% (MCP) and 14.2% (HCP), respectively. Hanwoo steers in each treatment were fed diets containing rice straw (20%) and concentrates (80%). CP intake was 5.5, 7.8 and 10.7g/BW0.75 for LCP, MCP and HCP, respectively. Protein balance was －0.05, 2.36 and 4.07g/BW0.75 for LCP, MCP and HCP, respectively. Intercept of the regression equation between CP intake and retained CP indicated that CPm was 5.56g/BW0.75. The estimate of CPm adopted by Korean Feeding Standard (2002) was almost 20% higher than that adopted by Japanese Feeding Standard for Beef Cattle (2000); this would need to be verified with more feeding trial data set including protein requirements for growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.227-231
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• 1984

Chinese CGMS (Cytoplasmic-Genetic Male Sterility) is being transfered to Korean cultivars which will be used as CGMS maintainers. These maintainer lines along with the Chinese CGMS lines and their maintainer lines were crossed with another group of Korean cultivars which will be used as the fertility restorers, and their yield heterosis were examined. The yield heterosis was calculated as high as 113.0-221.1 % in terms of heterosis (F$_1$/Midparent) with the grand mean of 150.5%, and, 86.1-179.8% in terms of heterobeltiosis (F$_1$/better parent) with the grand mean of 125.3%. Among the female parent groups, Chinese mainteiners were the highest following by Chinese MS lines and the Korean maintainers were the lowest. Heterobeltiosis of yield components were 92.7%, 120.0%, 103.0% and 112.0% for number of panicles/unit area, number of grains/panicle, fertility per cent and 1000 grain weight, respectively. Path-coefficients of yield components to the yield were calculated. The highest one was number of grains per panicle ranging 0.8073-0.8649 followed by the 1000 grain weight ranging 0.2000-0.5032. The grain yield ratios to the grand mean were calculated in terms of combining ability. It was highest with the Chinese maintainers followed by Chinese MS lines and The Korean maintainers were lowest. This facts bring cautions to the breeding efforts to transfer the Chinese CGMS in to Korean maintainers.