• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.31-39
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• 2021

In this study, the fiber blending ratio and strain rate effect on the tensile properties synergy effect of hybrid fiber reinforced cement composite was evaluated. Hooked steel fiber(HSF) and smooth steel fiber(SSF) were used for reinforcing fiber. The fiber blending ratio of HSF+SSF were 1.5+0.5, 1.0+1.0 and 0.5+1.5vol.%. As a results, in the cement composite(HSF2.0) reinforced with HSF, as the strain rate increases, the tensile stress sharply decreased after the peak stress because of the decrease in the number of straightened pull-out fibers by increase of micro cracks in the matrix around HSF. When 0.5 vol.% of SSF was mixed, the micro cracks was effectively controlled at the static rate, but it was not effective in controlling micro cracks and improving the pull-out resistance of HSF at the high rate. On the other hand, the specimen(HSF1.0SSF1.0) in which 1.0vol.% HSF and 1.0vol.% SSF were mixed, each fibers controls against micro and macro cracks, and SSF improves the pull-out resistance of HSF effectively. Thus, the fiber blending effect of the strain capacity and energy absorption capacity was significantly increased at the high rate, and it showed the highest dynamic increase factor of the tensile strength, strain capacity and peak toughness. On the other hand, the incorporation of 1.5 vol.% SSF increases the number of fibers in the matrix and improves the pull-out resistance of HSF, resulting in the highest fiber blending effect of tensile strength and softening toughness. But as a low volume fraction of HSF which controlling macro crack, it was not effective for synergy of strain capacity and peak toughness.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1161-1167
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• 2018

In order to cope with dramatically increasing malware variant, malware classification research is getting diversified. Recent research tend to grasp individual limits of existing malware analysis technology (static/dynamic), and to change each method into "hybrid analysis", which is to mix different methods into one. Futhermore, it is applying machine learning to identify malware variant more accurately, which are difficult to classify. However, accuracy and scalability of trade-off problems that occur when using all kinds of methods are not yet to be solved, and it is still an important issue in the field of malware research. Therefore, to supplement and to solve the problems of the original malware classification research, we are focusing on developing a new malware classification system in this research.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.217-226
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• 2024

This study is a descriptive research study to figure out the effect of unstable an adult attachment, self-mercy and emotional recognition clarity on interpersonal skills targeting nursing freshman. From 27th of March 2023 to 7th of April 2023, data gathered from the nursing freshman of university in J city, G province were analyzed. Using IBM SPSS/25, the data was analyzed descriptive statistic t-test, ANOVA and multiple correlation analysis. Interpersonal skills have negative correlation with unstable adults attachment(r=-.19, p=.005), and also have positive correlation with self-mercy (r=.38, p<.001) and emotional recognition clarity (r=.28, p<.001). Using hierarchical multiple regression analysis of factors that effects on interpersonal skills of survey subjects, self-mercy was the factor predict one's interpersonal skills the most, extroverted, mixed and emotional recognition clarity in order. The higher self- mercy and emotional recognition clarity are, the bigger influences interpersonal skills have and 24.5% of explanatory power. For nursing school students, interpersonal skills was one of the essential qualities so various methods to improve their interpersonal skills should be figured out.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4960-4968
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• 2015

In this study to improve the chloride durability of the shotcrete structure depending on types and contents of mineral admixture chloride resistance was evaluated by NT BUILD 492 of european test standards. It was also evaluated with the mechanical properties such as static strength and chloride penetration resistance. For shotcrete mixed crushed stone aggregate of the maximum size 10mm of coarse aggregates was produced. Based on 28days compression strength the variable mixed with 15% silica fume showed the highest strength in 67.55MPa. As the content of fly ash and blast furnace slag increased, the strength lowered. In the chloride penetration resistance test, OPC showed "high grade" and In the case of admixture, the penetration resistance tended to increase in all variables except the fly ash. In order to evaluate the service life, the accelerated chloride penetration test was conducted by the standards of KCL, ACI, FIB. Test results were obtained with the lowest spreading factor in a variable mixed with silica fume of 15%. At the KCI standards, It was found to have a service life of about 65 years and at the FIB standards, It was found to have a service life of 131 years. Among standards, the service life of KCI standard in all of the variables was evaluated as the lowest.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.55-61
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• 1979

Since rice high yielding practices with blast resistant varieties induced severe and earlier infestation of sheath blight recently, it is strongly suggested to spray at least 10 days earlier than the present recommendation and more than 2 sprays from early July to early August seems to be essential for the efficient control of sheath blight in the future. Among organo-arsenic fungicides, MAFe (Neo Asozin) is known as the most effective and economic as well as with the advantages of free phytotoxicity and safe residure on rice, and applications of the mixed formulation with other fungicide and insecticide is suitable for the one-hit control of rice diseases and insect pests in connection with cooperative mass control system. Present level of arsenic $(As_2O_3)$ residue in .ice is summarized as 0.2ppm to 0.65 ppm in highest average, and there are more possibilities of extensive MAFe fungicide uses for the efficient and economic control of this disease. During the past few years, the acreage of sheath blight control has been extended several times while the increase of the fungicides used for sheath blight showing about 10 times in quantity and mort than 15 times in amount, and also the fungicide cost estimated for the control is differ from 1 to 12 billion 1on by the use of MAFe or antibiotic fungicide in a year.

• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.55-67
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• 2006

A survey of 31 organic farmers were conducted to investigate the actual conditions of organic matter application. The amounts of organic matter application in the fields were higher in order of fruit, vegetable and rice farm. The average was 50 ton/ha in vegetable farms. In the green vegetable farms saw dust and animal manure were mainly utilized to make compost. Rice straw, wood chip, and forest bushes were also used for composting. In the fruit vegetable farms materials relatively lower in nitrogen content such as rice straw and cattle manure were used in vegetative period and materials higher in nitrogen content such as oil cake and wild grass were used in reproductive phase. Nutrient balance investigated in the farm in Icheon region who produce lettuce, angelica, and kale continuously in one cropping year indicated surplus in three major nutrients. Nitrogen and phosphorous were in excess by 29 and 10 kg respectively in the organic rice farm in yang-pyoung region. While soil chemical properties in the organic farms are within the adequate range in open field, it is much higher than the limits in the greenhouse soils. Overall application of organic matter is in an oversupply state. This results suggested that the organic matter management should be based on the soil conditions for sustainable cultivation. Chemical composition of organic matters and soil test reports should be considered prior to the application of organic matter.