• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.301-307
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• 2014

In order to reduce the emission of carbon dioxide($CO_2$), this research use blast furnace slag in concrete manufacture, as 100% replacement of cement. The aim of this study is to investigate the density and strength properties of alkali-activated lightweight composites with alkali activators of different types and different amounts. The bubble for achieving the lightweight of alkali-activated lightweight composites was generated in the reaction between the paper ash and the alkali activators instead of using a foaming agent. Lightweight formed concrete was conducted basic experimental for determining replacement ratio of paper ash. Then, the density and strength were measured according to the types and the contents of the alkali accelerator that can react with the paper ash. As results, the optimum replacement ratio of the paper ash was 5%. The alkali activator containing NaOH 12.5% obtained the lowest weight of $1.13g/cm^3$. Also, compressive strength were relatively high. Therefore, this study demonstrated that alkali accelerator with a certain amount of NaOH can achieve relatively high strength and lightweight alkali-activated lightweight composites.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.389-396
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• 2014

This study was conducted as the basic research for the replacement of Blast Furnace Slag, Red Mud, Silica Fume, etc., with cement as a solution to the problems arising from the global warming caused by the generation of $CO_2$, and conducted the experimental review to examine the feasibility of matrix having properties identical to those of cement by using the Blast Furnace slag, Red mud, Silica fume, and alkali-activator. For this, by using the the inorganic binder, such as Blast Furnace Slag, Red Mud, Silica Fume, etc., and NaOH, $Na_2SiO_3$ and others as the cement substitute material, the strength characteristic according to the mixture time variation was performed in the tentative experiment. Based on the preceding experiment, this study performed the experiment to analyze the strength properties of hardener through the curing by air-dry temperature, curing by temperature in water, coating curing, and Korean paper curing. For the water curing at $80^{\circ}C$, the compressive strength and flexural strength were found to be the most excellent at the age of the 28th day, and furthermore, it was found that the non-cement hardener could be made, which is considered to affect the production of eco-friendly concrete.

• The Korean Journal of Elementary Counseling
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• v.11 no.1
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• pp.21-33
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• 2012

This study examined the differences of academic achievement by social status types through sociometry. This study analyzed 201 students in grade 6 in S elementary school. The social status is classified by 7 (popular, average, rejected, aggressive-rejected, submissive-rejected, neglected, controversial) with academic achievement of each type as dependent variables to figure out the relation between social status types and academic achievement. To classify 5 social status types, a sociometry program developed by Ahn, Ie-Hwan (2007) was used, 2 social status types was classified with experimental condition, and its dependent variable was the score by subjects in the mid-term exam of the 1st semester in 2011. The average values of humanities courses (Korean and social studies) and natural science courses (math and science) were compared by both sexes and 7 social status types. The reference group was average group. As a result, as to male students, N type had the highest score both in humanities courses and natural science courses while C type had the lowest score in both groups. As to female students, P, N, C types had the highest score in both groups with similar range while R type had the lowest score in both groups. This result demonstrates that the academic achievement of students had relatively high relevance with social status. and also, suggestion that how teachers can do to enhance the academic achievement of elementary school students.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.4
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• pp.268-273
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• 1993

With a purpose of finding out the effects of phosphatic fertilizer application at the grassland establishment and management on the botanical composition, mineral content of grasses and the chemical properties of soil. a field experiment was arranged with four treatments as a randomized complete block design and lasted from September, 1989 to October, 1991 in hilly area near Suweon. The results obtained are summarized as follows; 1. The botanical composition of grassland that phosphatic fertilizer was not applied was poor and the rate of legumes was increased with phosphatic fertilizer application and the effect of phosphatic fertilizer applications was obvious at the grassland management. 2. The mineral contents, N. P, Ca, Mg of grasses were increased with phosphatic fertilizer application but the K/Ca+Mg equivalent ratio of grasses was lowered and K content and Ca/P ratio tended not to be regular. 3. The available phosphorus contents and exchangable cation, Ca, Mg, contents of grassland soil were increased with phosphatic fertilizer applications but potasium contents tended not to be regular. 4. It was necessary to apply phosphatic fertilizer for the establishment and management of grassland. The botanical composition of grassland that phosphatic fertilizer was not applied at the establishment could be corrected into good stand with continuous phosphatic fertilizer applications at the management.

• Applied Biological Chemistry
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• v.16 no.3
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• pp.128-136
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• 1973

An experiment was carried out to study the effects of Zn application on the rice plant of IR-667 and Jinheung varieties grown under the conditions of poor drainage and low available Zn. The results obtained were an follows; 1. The poor drained condition of the paddy field was more favorable for Zn utilization by the rice plants than the well drained condition. Also Zn application in the form of Zinc chloride $(ZnCl_2)$ seemed to significantly increased the rice yield of both IR-667 and Jinheung. 2. Zn content of IR-667 was much higher than that of Jinheung. The concentration of Zn in IR-667 rice plant treated by Zn fertilizer was about 200 ppm while that of control plot (not received Zn fertilizer) only 30 ppm. This result suggests that Zn application might improve the yield under the condition of poor drained soil when Zn concentration of IR-667 rice plant is around 30 ppm. 3. Absorption of Zn-65 by the rice plant was greater in the plants grown without Zn fertilizer than those with Zn fertilizer application, At harvest, the higher amount of Zn-65 was accumulated in the gram than in the straw. 4. Zn fertilization increased the grain yield in the soil of Paju, Dalsung, Chilg ok and Chungwon with low available Zn.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.241-252
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• 2020

The purpose of this research is to study the effect of soldiers' self-development during military service on returning university students' self-directed learning and job preparation Behavior. The object of this study are 323 students among second, third and fourth graders of about 15 universities' nationalwide by online stratified clusterrandom sampling. SPSS 25.0 program was used for data analysis and factor analysis, frequency analysis, independent t-test, one way ANOVA, multiple regression analysis were done. The rusult are as follows :First, self-directed learning and job preparation behavior according to personal characters have meaningful differences in university location, grade, degree of self-development during military service, degree of self-development during military service, self-development during military service, e-learning study during military service, gaining credits during military service, gaining national licence during military service and receiving money for self-development during military service. Second, The experience of self-development during military service has meanigful difference in returnig university students' self-directed learning and job preparation behavior.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.306-306
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• 2009

본 실험은 백세주 주정박이 벼의 생육과 토양 비옥도 개선에 미치는 영향을 조사하였다. 백세주 주정박은 압착된 주박을 재 발효시켜 단식증류기로 증류하여 알코올을 회수 후 발생된다. 실험 처리구는 무시용, 요소, 주정박 처리구로 하였고, 벼 질소비료 표준시비량 11kg N/10a를 기준으로 하여 전량 기비로 사용하였다. 백세주 주정박의 유효성분과 유해성분을 분석하였고, 토양에 주정박을 시용 전 후의 이화학적 분석을 하였다. 벼 실험 품종은 오대벼(Oryza sativa L.)이고, 벼의 생육과 수량 및 미질을 분석하였다. 백세주 주정박의 pH는 3.60, 유기물함량 90.12%, 염농도 0.72ds/cm, 수분함량 88%, 질소 0.21%, 인산 0.24%, 칼리 0.09%로 나타났다. 유해성분(중금속)분석결과 비소 0.03ppm, 크롬 0.09ppm, 구리0.91ppm, 납 0.05ppm, 니켈 0.05ppm, 아연 1.30ppm, 망간 3.28ppm, 철 34.86ppm로 나타났다. 토양이화학적 분석결과 주정박 시용처리구의 유기물함량과 질소 및 인산은 각각 23.0g/kg. 0.11%, 89mg/kg로 무시용과 요소처리구에 비해 유의한 차이를 보였다. 벼 이식 후 140일째 생육분석결과 초장 82.60cm, 옆폭 1.40cm, 옆장 37.70cm, 지상부건물중 59.21g로 다른 2개 처리구에 비해 유의한 차이를 보였다. 벼의 수량은 주정박 시용 처리구가 449.0kg/10a로 무시용 89.66kg/10a와 요소 401.66kg/10a에 비해 유의적인 차이를 보였다. 백세주 주정박 시용을 통해 토양 개량 효과를 기대할 수 있고, 공시 토양의 토양 개량 효과가 벼의 생육에 긍정적인 영향을 끼치는 것으로 나타남에 따라 백세주 주정박의 토양개량제로서의 활용 가능성을 확인하였다.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.379-388
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• 2016

This study was aimed at identifying the actual state of workplace violence based on a survey conducted to 876 subway workers in Seoul and determining the relationship between workplace violence and mental health of workers. Data were collected via web site, using a structured questionnaire and for the analysis of the data, a multiple linear regression analysis was carried out by the statistical program SPSS 20.0. According to the results, the perpetrators of violence turned out to be "passengers" in all types of workplace violence: physical violence, verbal violence, sexual harassment and disregard for personality. As for the relationship between workplace violence and the mental health of the workers, statistically significant differences were shown between all the above mentioned workplace violence types and sub-areas of mental health. Also, as for the impact of workplace violence on the mental health of the workers, significant differences were found in physical violence, sexual harassment and disregard for personality, with 8.3 percent of explanatory power. Based on these findings, the study suggests the establishment and the application of customer interaction guidelines to protect subway workers from workplace violence along with specific measures customized for each work environment to prevent violence.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.355-365
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• 2015

This study examined the fluidity and strength properties, water resistance, durability, and freeze-thaw of cementless loess mortar using an eco-friendly hardening agent. The experimental result indicates that 28 days compressive and flexural strength of the loess mortar was increased regardless of the weathered granite soil and loess mixture ratio as the replacement ratio of the hardening agent increases. The strengths were significantly increased until 14 days regardless of the hardening agent, while the effect on the strengths increasement was relatively low after 14 days. Thus, the strength development of loess mortar concrete was found to be faster than that of the normal concrete. In addition, when the hardening agent of 10% was used, the average flexural strength was 1.7MPa which is insufficient compared to the 28-day flexural strength of 4.5MPa for the paving concrete. However, the flexural strengths of the loess mortar concrete using the hardening agents of 20% and 30% were 4.0MPa and 5.3MPa, respectively. Thus, the hardening agent need to be at least 20% so that the loess mortar can be used for paving concrete. The experiment for water resistance shows that the repeated absorption and dry reduced mass regardless of the mixing ratio of the loess. The maximum length change also decreased with increasing the substitution rate loess mixture ratio and the hardening agent. The result of the freeze-thaw resistance test indicates that the relative dynamic modulus of elasticity at 300 cycle freeze-thaw with the hardening agents of 20% and 30% were 75% and 79%, relatively. Thus, the hardening agent of at least 20% is required to obtain the relative dynamic modulus of elasticity of 60% for the loess mortar.

• International Commerce and Information Review
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• v.13 no.4
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• pp.275-295
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• 2011

Any attempt which requires banks to consider non-documentary conditions would destroy autonomy principle and increase the risks of the bank in L/C transactions. Therefore, non-documentary conditions are disregarded in the letter of credit. This provision was first introduced in UCP500, but later, ICC Position Paper No.3 added that if L/C requires documents related to non-documentary conditions, it cannot be disregarded. While the language in UCP600 is basically the same as that in UCP500, there is a difference between the two in that the former disregards the documents related to non-documentary conditions even if they are required by L/C. However, it should be remembered that international standard banking practice does not disregard all of non-documentary conditions. It recognizes the validity of some non-documentary conditions which it is not feasible to change into documentary conditions. That is, such non-documentary conditions as can be determined from an index specified in the guarantee or identified from the issuing bank's own records or their normal operations are recognized as valid in legal cases. ISP98 and UR00758 do not consider these as non-documentary conditions. The applicant should be cautious not to include non-documentary conditions in their applications.