• Proceedings of the Safety Management and Science Conference
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• 2005.11a
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• pp.569-579
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• 2005

International capital movement has made progress at global liberalization of finance and foreign exchange, international monetary norm changing into floating exchange rate system, easiness of collection of information and trade at improvement of information communication technology from early of 1970's. Results of empirical test for relation between foreign exchange rate or various determination factors of foreign exchange rate and interest rate are followed by next sentences. First, according to relation between foreign exchange rate and interest rate, correlation for each of variables after OECD entrance is increased. 'But, long-term & short-term interest rate is affected by Hanbo & Kia's bankruptcy, continuous large scale coporates bankruptcy and crisis of foreign exchange. Therefore, financial instability is occured. If portfolio investment fund has been inflow as it is mollified by continuous shortage of foreign exchange and fall of country's credit rating, it is expected to have positive effect for long-term & short-term interest rate from appreciation of won against dollar. Second, results from relation between determination factor of foreign exchange rate and interest rate are followed by next sentences. If surplus of current account and goods account is continued, yield of corporate bond is to be stable. But, margin of surplus is expected to diminish after second quarter 98, and difference between external and domestic interest (after adjusting foreign exchange rate) is to be diminished. And if net inflows of foreign investor's fund (stock and bond) is diminished, it is to have negative effect for yield of corporate bond. According to foreign investor's investment movement of previous years, hedge fund were stayed at least during two years in Mexico. It means that sudden capital outflow is not to be happened at Korea.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.317-323
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• 2014

Odyssey, one of the NASA's Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of $^{40}K$, $^{232}Th$ and $^{238}U$ in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1053-1064
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• 2009

The existence of a large sodium pool in the KALIMER, a pool-type LMR developed by the Korea Atomic Energy Research Institute, plays an important role in reactor safety and operability because it determines the grace time for operators to cope with an abnormal event and to terminate a transient before reactor enters into an accident condition. A two-dimensional hot pool model has been developed and implemented in the SSC-K code, and has been successfully applied for the assessment of safety issues in the conceptual design of KALIMER and for the analysis of anticipated system transients. The other important models of the SSC-K code include a three-dimensional core thermal-hydraulic model, a reactivity model, a passive decay heat removal system model, and an intermediate heat transport system and steam generation system model. The capability of the developed two-dimensional hot pool model was evaluated with a comparison of the temperature distribution calculated with the CFX code. The predicted hot pool coolant temperature distributions obtained with the two-dimensional hot pool model agreed well with those predicted with the CFX code. Variations in the temperature distribution of the hot pool affect the reactivity feedback due to an expansion of the control rod drive line (CRDL) immersed in the pool. The existing CRDL reactivity model of the SSC-K code has been modified based on the detailed hot pool temperature distribution obtained with the two-dimensional pool model. An analysis of an unprotected transient over power with the modified reactivity model showed an improved negative reactivity feedback effect.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.765-772
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• 2016

In analyzing residual radiation, researchers generally use a two-step Monte Carlo (MC) simulation. The first step (MC1) simulates neutron transport, and the second step (MC2) transports the decay photons emitted from the activated materials. In this process, the stochastic uncertainty estimated by the MC2 appears only as a final result, but it is underestimated because the stochastic error generated in MC1 cannot be directly included in MC2. Hence, estimating the true stochastic uncertainty requires quantifying the propagation degree of the stochastic error in MC1. The brute force technique is a straightforward method to estimate the true uncertainty. However, it is a costly method to obtain reliable results. Another method, called the adjoint-based method, can reduce the computational time needed to evaluate the true uncertainty; however, there are limitations. To address those limitations, we propose a new strategy to estimate uncertainty propagation without any additional calculations in two-step MC simulations. To verify the proposed method, we applied it to activation benchmark problems and compared the results with those of previous methods. The results show that the proposed method increases the applicability and user-friendliness preserving accuracy in quantifying uncertainty propagation. We expect that the proposed strategy will contribute to efficient and accurate two-step MC calculations.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.624-634
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• 2016

Nuclear criticality safety analyses (NCSAs) considering burnup credit were performed for the GBC-32 cask. The used nuclear fuel assemblies (UNFAs) discharged from Hanbit Nuclear Power Plant Unit 3 Cycle 6 were loaded into the cask. Their axial burnup distributions and average discharge burnups were evaluated using the DeCART and Multi-purpose Analyzer for Static and Transient Effects of Reactors (MASTER) codes, and NCSAs were performed using SCALE 6.1/STandardized Analysis of Reactivity for Burnup Credit using SCALE (STARBUCS) and Monte Carlo N-Particle transport code, version 6 (MCNP 6). The axial burnup distributions were determined for 20 UNFAs with various initial enrichments and burnups, which were applied to the criticality analysis for the cask system. The UNFAs for 20- and 30-year cooling times were assumed to be stored in the cask. The criticality analyses indicated that $k_{eff}$ values for UNFAs with nonuniform axial burnup distributions were larger than those with a uniform distribution, that is, the end effects were positive but much smaller than those with the reference distribution. The axial burnup distributions for 20 UNFAs had shapes that were more symmetrical with a less steep gradient in the upper region than the reference ones of the United States Department of Energy. These differences in the axial burnup distributions resulted in a significant reduction in end effects compared with the reference.

• Nuclear Engineering and Technology
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• v.45 no.6
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• pp.721-730
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• 2013

Within the framework of the ASTRID project, core design studies are being conducted by the CEA with support from AREVA and EDF. The pre-conceptual design studies are being conducted in accordance with the GEN IV reactor objectives, particularly in terms of improving safety. This involves limiting the consequences of 1) a hypothetical control rod withdrawal accident (by minimizing the core reactivity loss during the irradiation cycle), and 2) an hypothetical loss-of-flow accident (by reducing the sodium void worth). Two types of cores are being studied for the ASTRID project. The first is based on a 'large pin/small spacing wire' concept derived from the SFR V2b, while the other is based on an innovative CFV design. A distinctive feature of the CFV core is its negative sodium void worth. In 2011, the evaluation of a preliminary version (v1) of this CFV core for ASTRID underlined its potential capacity to improve the prevention of severe accidents. An improved version of the ASTRID CFV core (v2) was proposed in 2012 to comply with all the control rod withdrawal criteria, while increasing safety margins for all unprotected-loss-of-flow (ULOF) transients and improving the general design. This paper describes the CFV v2 design options and reports on the progress of the studies at the end of pre-conceptual design phase 1 concerning: - Core performance, - Intrinsic behavior during unprotected transients, - Simulation of severe accident scenarios, - Qualification requirements. The paper also specifies the open options for the materials, sub-assemblies, absorbers, and core monitoring that will continue to be studied during the conceptual design phase.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.720-729
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• 2016

This study was the effect of depression, anxiety, stress on suicidal ideation for some of the elderly living in the Youngdong county. Then it establishes alternatives for elderly suicide prevention and community improvements to help improve the quality of life of the elderly. For this study, a random sampling of 367 people aged sixty or older living in the eleven villages in Youngdong county participated in a survey. As a result, depression, anxiety and stress affects suicid in the positive direction. The correlation between depression, anxiety, stress, and suicidal ideation was significant. The relationship between depression and anxiety was highest and the probability is less than 0.05. As an alternative to the Elderly Suicide Prevention, First, mental health census and management for elderly, Second, a need to provide jobs for the elderly. Third, it requires a tight safety net of health and safety officer with reinforcements. Fourth, there is a need for enhanced recognition of life-love.

• Korean Security Journal
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• no.37
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• pp.295-323
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• 2013

This study's purpose examine the "Four Social Evils" policy during about seven months and presents new policy and policy directions with a critical eyes. The present Government focus 'The safety of the people' in 2013. But, most of all, "Four Social Evils" selected the top priority project of the government that will be worked on for the next five years. "Four Social Evils" means Sexual Violence, School Violence, Domestic Violence and Unsanitary Food as crimes affecting the daily lives of the people. To date, we were having a number of discussions with various people. But currently, there is a lack of research on constructive criticism about "Four Social Evils" policy. Therefore, It is the best thing to get interested in "Four Social Evils" policy and evaluate the effectiveness at this time. But, This study is not simply criticizing the "Four Social Evils" policy. Ultimately, through this constructive criticism, this study is trying to encourage "Four Social Evils" policy in the right direction and serve as the groundwork for reinforcement strengthen of the social safety net.

• Journal of Food Hygiene and Safety
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• v.22 no.2
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• pp.93-98
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• 2007

Acute toxicity of WK-38, a herbal preparation for the atherosclerosis, was examined using male and female Sprague-Dawley rats. WK-38 is composed of Rhei Rhizoma, Magonoliae Cortx, Moutan Cortex Radicis. Rats were treated with the WK-38 intragastrically at 0 mg/kg, 5 mg/kg, 50 mg/kg, 500 mg/kg or 2,000 mg/kg and observed for two weeks. No mortality was observed at the doses used. Abnormal clinical signs such as eye bleeding, nasal bleeding and hyperemia had been shown temporary after administration. All rats were appeared to be healthy and normal during the 2 week observation. Also there was no difference in net body weight gain, gross pathological findings, and urine analysis among the groups rats treated with different doses of the WK-38.

• Korean Journal of Health Education and Promotion
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• v.33 no.3
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• pp.95-107
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• 2016

Objectives: Physical activity is well known as one of the most effective health behaviors for maintaining and promoting health. The purpose of this study was to investigate the regional variation, compositional and contextual factors on physical activities in Korea. Methods: This study analyzed data of 6,353 adults in 4th-1, 2 Korea National Health and Nutrition Examination Survey (KNHANES). Independent variables were compositional factors that included general characteristics, health behaviors, health status, and contextual factors that included physical environment, political environment, and social safety net. Dependent variables were vigorous physical activity, moderate physical activity, and walking activity. Multilevel analysis were used to determine a variation of physical activity between levels of compositional factors and contextual factors. Results: Physical activities of the Korean people were affected by the regional variables. Financial independence and population density were related with moderate physical activity significantly. Population density, school sport or rally spaces, cultural facilities, and social safety concerns were related with walking activity significantly. These variables impacted on physical activities along with variables at the individual level. Variance Partition Coefficient were 9.94% at moderate physical activity and 2.91% at walking activities, respectively. Conclusions: The results suggest that the regional variables should be considered when planning public intervention to promoting physical activities in Korean adults.