• Journal of Conservation Science
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• v.26 no.4
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• pp.397-406
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• 2010

The most ideal method to measure the water-soluble $Cl^-$ ion eluted from iron artifacts is conducting the analysis on desalting solution by Ion Chromatography. But most institutes related to cultural heritages use Cl meter by reason of lack of budget and experts. This study evaluated reliability and stability between Cl meter and Ion Chromatography by doing cross-validation with results from two methods to detect $Cl^-$ ion of desalting solution. From D.I water, extremely small quantities of $Cl^-$ ion was detected by the influence of remaining water-soluble $Cl^-$ ion at the electrode of Cl meter and water-soluble $Cl^-$ which remains in Sodium sesquicarbonate, components of reagent was detected as well. The first desalting solution had the most $Cl^-$ ions, $Cl^-$ ion slightly decreased from the second to the fourth desalting solution and tend to decrease again at the stage of dealkalified in D.I water. Each Cl meter has the standard deviation according to the measured numbers and the higher concentration of $Cl^-$ ion the desalting solution has, the wider the deviation is. But when the concentration of $Cl^-$ ion is low, it was stable to use Cl meter to detect the concentration of $Cl^-$ ion from iron artifacts because there is the small deviation, It is thought that conductivity meter method is not suitable for measuring $Cl^-$ ion, because the electrical conductivity of alkaline solution is too high to measure $Cl^-$ ion.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.504-517
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• 2018

The purpose of this study is to analyze the trends and contents of the research related to young children safety published in the domestic KCI and the candidate journals from 2010 to 2017. To analyze this, we selected 75 articles related to safety for young children published in the KCI and candidate journals from 2010 to 2017. A total of 75 papers were analyzed for frequency, percentage and ${\chi}^2$ using the SPSS Win 23.0 program. The main results of this study are as follows: First, the articles related to young children safety were published the most in 2016 and 2017 and related to infant safety were the least. Next, more than half of the research methods were conducted by quantitative research methods. The results of this study are meaningful in that it presents the necessity of safety education by analyzing trends and contents of research related to young children safety in situations where safety accidents for young children are frequent and the importance of young children safety is more emphasized. It is expected that this research will provide basic data on research topics such as disaster safety who need further research.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.425-438
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• 2018

Existing studies that analyze the causes and effects of water circulation use mostly rainfall - runoff models, which requires much effort in model development, calibration and verification. In this study, hydrological sensitivity analysis which can separate quantitatively the impacts by natural factors and anthropogenic factor was applied to the Hwacheon dam upper basin from 1967 to 2017. As a result of using various variable change point detection methods, 1999 was detected as a statistically significant change point. Especially, based on the hydrological sensitivity analysis using 5 Budyko based functions, it was estimated that the average inflow reduction amount by Imnam dam construction was $1.890\;billion\;m^3/year$. This results in this study was slightly larger than the those by existing researchers due to increase of rainfall and decrease of Hwacheon dam inflow. In future, it was suggested that effective water management measures were needed to resolve theses problems. Especially, it can be suggested that the monthly or seasonal analysis should be performed and also the prediction of discharge for future climate change should be considered to establish resonable measures.

• Journal of the Korean Geotechnical Society
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• v.32 no.11
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• pp.83-96
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• 2016

The surface settlement of the back ground of a braced wall due to the ground excavation has the great influence on the safety of the surrounding area. But it is not easy to predict the settlement of the surrounding area due to proud excavation. Estimation of the settlement of the surface ground induced by the deformation of the braced wall is performed by FEM and empirical method (Peck, Clough etc). In this research, surface settlement of the back ground braced wall depending on the joint dips in rocks during excavating the composit ground was measured at the large scale model test (standard: $0.3m{\times}0.3m{\times}0.5m$). The scale of model test was 1/14.5 and the ground was excavated in ten steps. Earth pressure on the braced wall and ground surface settlement on the back ground of a braced wall were investigated. The surface settlement during the excavation depended on the joint dips in rocks on of the ratio of rock layer. Maximum earth pressure and maximum surface settlement were masured at the same excavation step. In accordance with the increase of the rock layer dips and rock layer ratio, the ground surface settlement increased. The maximum ground surface settlement was 17 times larger at 60 degree joint dips in rocks than that of the horizontal ground conditions. And the position of the maximum surface settlement by empirical method was calculated at the point, which was 17%~33% of excavation depth. In accordance with the increase of the rock layer dips and rock layer ratio, the ground maximum surface settlement increased. The ground surface settlement of composite ground is smaller than that of the empirical.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.523-533
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• 2015

A reactor containment acts as a final barrier to prevent leakage of radioactive material due to the possible reactor accidents into external environment. Because of the functional importance of the containment building, the SIT(Structural Integrity Test) for containments shall be performed to evaluate the structural acceptability and demonstrate the quality of construction. An initial numerical analysis was performed to simulate the results obtained from the SIT for a prestressed concrete(PSC) structure. But the analysis results by the initial model expected smaller displacements than the measured ones by 30% at some locations. Accordingly, the research and development to improve the initial model to corelate the measured results of the SIT more properly have been performed. In this paper, the effects of the loss of concrete due to duct for tendons and the contact of duct and tendons in un-bonded tendon system are mainly evaluated based on the preliminary analysis results. In addition, the importances of the proper definition of mesh connectivity among structural elements of concrete, liner plates, rebars and tendons are discussed.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.7-12
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• 2007

The search for a new fire-extinguishing agent with all the desirable properties of halon 1301 has not been successful. To study binary gaseous extinguishing agents instead, one has to determine the extinguishing concentrations for several compositions of a given chemical in an inert gas. This process is expensive and time consuming. The fire suppression efficiencies of gas mixtures of HFC 125 and HFC 227ea with nitrogen as total flooding agents were studied by cup burner method. It was shown that addition of small amounts of those extinguishants to nitrogen can enhance the suppression effectiveness of the inert gas. As expected, the degree of synergism was highest at low concentrations of the chemical. For each binary system, extinguishing concentrations of the pure compounds and one binary data were used to predict the extinguishing concentrations for the entire range of binary composition. The predicted values were very close to experimental data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.8074-8088
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• 2015

In this study, main focus was analyzing whether the retired middle-aged people's life style and personal characteristics affect house selection attributes and there are any differences according to their life styles. The finding and implications of this study were as follows. The middle-aged people were trying to pursue leisurely and healthy life. Therefore, they prefer the high service quality of health, medical facilities, culture, leisure, and entertainment facilities. These trends were caused by the expansion of the five-days working styles, the improvements of the smart consumptions, the high levels of the education, and the high social and economic participations of the females. The overall changes in social, cultural, economical circumstances made them different from other generations. Also current middle-aged people were more challenging and active and they thought themselves young compared with the people of the older generation. In the future those middle-aged people's life style will be more diversified. Therefore new housing plans are necessary for the middle-aged popple to satisfy their diverse housing needs and housing circumstances. Based on the results of this study for the middle-aged people's life style and housing selection attributes after their retirement, more studies are necessary in new and different views. Furthermore diverse house supplies, housing marketing, housing policies should be provided for the middle-aged people for their retirement and need to study more their future housing satisfaction and their housing needs.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.1
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• pp.49-54
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• 2012

Microbial changes in the characteristics of dissolved organic matter (DOM) and the subsequent effects on the conditional stability constants of copper were investigated using 14 day-incubations of Pony Lake fulvic acid (PLFA), Suwannee River fulvic acid (SRFA) and the mixtures of the humic substances and glucose. After incubation, dissolved organic carbon (DOC) concentrations were diminished, and specific UV absorbance values and DOC-normalized fluorescence intensities increased. The microbial changes were minimal for the samples contaning humic substances only whereas they were much pronounced for the mixtures with glucose. The extent of the changes increased with a higher content of glucose in the mixtures. The same trend was observed even for glucose solution. Our results suggest that labile organic moieties may be transformed into more chromophoric and humidified components by biodegradation. For the mixture samples, the copper binding stability constants did not change or even decreased after incubation. Therefore, microbially induced enrichment of the fulvic- and humic-like carbon structures in DOM appears to result in little change or the decrease of the copper binding coefficients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.923-933
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• 2014

The subject of investigation was 13,828 people who took periodical medical examiner in some health examination centers two times in 2009 and 2011 so as to analyze changes of borderline group, disease group for 4 diseases(hypertension, diabetes, liver disease, hyperlipemia) and health behavior of some medical examiner. For the contents of investigation, drinking and smoking habit was investigated as a general characteristic of subjects. For the items of health examination, there were SBP, DBP, AST, ALT, GGT, Glucose, Total Cholesterol and Triglyceride. The main results are as follows. In comparison with the starting year of research, drinking and smoking rate of the final year was reduced respectively by 1.6% and 1.4%. And, borderline group by examination items, hypertension was reduced by 2.2% from 62.0% to 59.8% in the final year in comparison with the starting year of investigation, And, fasting blood glucose was 17.1%, hyperlipemia was 6.6%, LFT was 2.0% for the reduction. In disease group, hypertension was reduced by 0.6% from 6.7% to 6.1%. And, fast blood glucose was 1.9%, hyperlipemia was 4.2%, LFT was 1.3% for reduction. Borderline group showed more reduction in comparison with disease group in all of items. The above results showed borderline group showed more reduction of manifestation rate than disease group in all of 4 diseases. Therefore, it's expected that disease group will show reduction in the future. But, it's necessary to study on future's changes through the continuous management and tracing observation.

• Journal of Korea Water Resources Association
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• v.41 no.10
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• pp.995-1007
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• 2008

Studies on modeling the rainfall-runoff relationship which shows nonlinear trend strongly use artificial neural networks theory not only for the prediction but also for the characteristics analysis of the data used by pattern classification. For the pattern classification, the results from Self-Organizing Map (SOM) mention that the map size and array for the SOM training have significantly influenced on the SOM performance. Since there is no deterministic method or theoretical equation to determine the number of rows and columns for the map size, hexagonal array is generally used for the map array. Therefore, this study present a determination of the optimized map structure for the rainfall-runoff analysis in Naju station considering the map size and array simultaneously which can represent the classified characterization of rainfall-runoff relationship. The result showed that the map size of 20$\times$16 hexagonal array with 8-clustered patterns was selected as an appropriate map structure for rainfall-runoff analysis in Naju station.