• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.259-266
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• 2018

In recent years, the early strength of concrete is important in order to shorten the time of form removal at the construction site. The purpose of this study is to analyze the moment of form removal as investigating the amount of cement contents and the physical properties and strength of the concrete according to types of admixture in the curing temperature of $10^{\circ}C$ for concrete of 21 to 27 MPa. As a result, it was found that compressive strength of concrete could not be secured 5 MPa by 36 hours even if the amount of cement contents were increased to $360kg/m^3$ with plain admixture. Also, it was confirmed that the strength improvement rate was excellent when using the accelerating agent with polycarboxylic acid type, and the moment of compressive strength of 5 MPa was estimated at 30 hours.

• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.112-119
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• 2017

In this study, the availability of cow manure as raw material for solid fuel production was investigated. Since the water content of the cow manure was too high, it was dewatered using a laboratory hydraulic compressure ($11.3kg/cm^2$). The moisture content of the cow manure decreased from 82.01% to 73.36 wt.%. The dewatered cow manure was homogenized by the experimental apparatus and then put into the rotating cylindrical apparatus. From the consecutive processes, the cow ball-shaped pellet which size ranged from 3.0 to 25.0 mm was produced. The major factor for making palletized fuel from cow manure was the moisture content. Based on the experimental data, the moisture content of cow manure for pelletizing cow manure was identified as 65~75 wt.%. When the moisture content of the cow manure was lower than 30 wt.%, the diameter of the pellets maded from cow manure was smaller than 3 mm. On the other hand, when the water content of the cow manure was higher than 75 wt/%, the diameter of the processed pellets tended to be larger than 25 mm. The characteristics of the processed cow manure pellets was analyzed to be in accordance with the livestock solid fuel quality standard. The pyrolysis characteristic of the pellet was analyzed by raising the heating temperature of the experimental equipment from 200 to $900^{\circ}C$. The mass change between of 20 and $130^{\circ}C$ corresponds to the amount of moisture contained in the cow manure. The amount of moisture was about 15% of the total weight of cow manure samples. The cow manure pellet was thermally stable up to $280^{\circ}C$. It can be interpreted that combustion of cow manure pellet does not occur until the surface temperature reaches $280^{\circ}C$. The mass change of pellet between of 280 and $450^{\circ}C$ was considered to be due to the vaporization of volatile organic compounds (VOCs) present in the cow manure pellet. The maximum production of VOCs was showed near $330^{\circ}C$.

• Journal of Animal Environmental Science
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• v.5 no.3
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• pp.157-170
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• 1999

This study was conducted to investigate the effects of Scoria, Quartz porphyry and Oak charcoal powder feeding by 1% level of concentrate on the fattening cross bred bulls(5/8 Korean Native Cattle, 2/8 Charolais, 1/8 Brahman germ plasma) Feeding trial was conducted with 4 treatment groups which were T1(Full feeding of concentrate and roughage for 12 months), T2(T1 and Scoria addition), T3(T1 and Quartz porphyry addition) and T4(Oak charcoal addition) for 360 days, consisting of 32 heads whose initially weights were about 299.7kg. The results obtained are summarized as follows; 1. During the over-all period, average daily gains by T3, T4, T2 and T1 were 1.024, 0.987, 0.977kg and 0.964, respectively, without a significant difference by treatments. 2. Concentrate intakes per body weight and TDN intakes required per unit of kilogram gain were lower in addition agent groups than in control, and in all the treatments feed efficiency was higher at early stage for 360 fattening day than at end stage. 3. Carcass weight, dressing percent, back-fat thickness and loin eye muscle area by treatments were 330.9 to 348.4kg(average 340.3kg), 55.2~56.2(average 55.8%), 0.41~0.55(average 0.46cm)and 76.0~80.9$\textrm{cm}^2$(average 77.6$\textrm{cm}^2$), respectively, and were improved in addition agent groups than in control. 4. Meat quality grade is higher in addition agent groups than in control, and heads of 1st grade by treatments was 3, 2, 1 and none in T4, T2, T3 and T1, respectively. 5. Incidence heads of diseases by treatment were not apparently different, but diseases of digestive system was decreased in addition agent groups than in control. 6. The nitrate nitrogen content of fattening bull dung which collected in rectum were 0.082~0.089% (average 0.084%), and the content in addition agent groups was smaller than in controll. 7. Income was higher in order of T4, T3, T2, and T1 and incomes of treatment groups were grater than that of control group by 21.4 to 33.5 percent. According to the above results it may be concluded that fattening bulls may be required to feed no more than 1% of Scoria, Quartz porphyry and Oak charcoal powder based on the concentrate feeding level during the fattening period(12 to 24 month of age) to produce high quality meat and increase income.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.492-492
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• 2018

'물발자국(Water Footprint)' 개념은 가상수의 개념이 확장된 것으로 제품 생산과 서비스 전 과정에서 사용된 물의 양을 나타낸다. 따라서 한 국가내의 수자원 총량의 산출 시에 국제 무역을 통해 수출-수입되는 가상수의 양까지 고려하여 국가 물 총합(Water Budget)을 계산한다. 본 연구는 가상수의 수자원 활용에 관한 산업적 차원의 비교를 위하여 산업별 물발자국 산정모델을 구축하고자 하였다. 산업별 물발자국을 산정하기 위하여 첫째, 산업별 용수사용량에 기초하여 물발자국을 산정하였고, 둘째, 단위 물발자국에 기초하여 산업별 물발자국을 산정하였다. 먼저 산업별 용수사용량에 기초한 물발자국 산정은 하향식 접근법을 적용하였다. 국가 산업별 물발자국을 산정한 결과, 산업 전체 물발자국은 약 330억$m^3$이며 그 중 농업계가 연간 118.8억$m^3$으로 전체 물발자국의 36%를 차지하였다. 그 다음은 생활계로 전체의 34%인 111억 4천만$m^3$이다. 축산계의 물 사용량은 연간 2억 6천 7백만$m^3$ 정도이지만, 오염물질을 정화하는데 필요한 물인 회색수의 양이 많아 물발자국이 73억 $m^3$으로 비교적 높게 산정되었다. 공업계의 가상수량은 연간 26억$m^3$으로 타 산업에 비하여 오염부하량이 높지 않아 회색수량이 작게 나타났다. 다음으로 단위 물발자국에 기초하여 산업별 물발자국을 산정하였다. 단위 물발자국과 생산량을 활용하여 산정하는 상향식 접근법을 활용하였다. 1980년대부터 2014년까지 쌀 외 18개 품목에 대한 농산물 생산의 물발자국을 산정한 결과, 전체 물발자국은 평균 90억$m^3$으로 추정되었다. 한편, 2차 산업의 물발자국은 산업연관분석을 활용하여 산정하였다. 산업연관분석을 위하여 한국은행의 산업연관표와 경제총조사의 용수비 항목을 활용하였다. 2차 산업의 총 물발자국을 산정한 결과, 60억 $m^3$으로 추정되었다. 3차 산업의 물발자국도 이와 동일한 방식으로 산업연관표를 활용하여 산정하였다. 산업연관분석을 활용한 3차 산업의 물발자국 산정한 결과, 숙박 및 음식점업에서의 물발자국이 가장 큰 것으로 산정되었다. 이에 따라 Case Study로서 국내 워터파크 대상으로 물발자국을 산정하였다. 자료가 없는 부분을 제외하고 연간 총 840만 $m^3$의 물발자국을 가지는 것으로 나타났으며, 이 중 직접수는 70만 $m^3$, 간접수는 770만 $m^3$으로 간접수의 비율이 92%를 차지하였다.

• Korean Journal of Breeding Science
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• v.43 no.4
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• pp.330-336
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• 2011

A comparative study was conducted on genetic correlation between 12 open-pollinated families (32-year-old) and their one-year-old seedlings for early selection on the fast-growing trait in Pinus densiflora S. et Z.. Those twelve families were divided into three groups such as superior, intermediate, and inferior, on the base of the growth indexes of 32-year-old P. densiflora. The growth performance of the 32-year-old P. densiflora showed significant correlation with the growth traits of their one-year-old seedlings. Dry weights of the seedlings had significant correlation (P < 0.01) with the growth index of the adult plants and its $R^2$ value was 0.597, suggesting that 59.7% of the families could be selected by using dry weights of one-year-old seedlings. Furthermore, the growth rates of seedling heights for superior, intermediate, and inferior groups were 4.568, 3.773, and 3.535, respectively, resulting that seedlings of the superior group grew approximately 1.3-fold faster than those of the inferior group. Therefore, we concluded that two growth traits of one-year-old seedlings dry weight and growth rate were suppose to the early selection factors for the fast-growing trait for P. densiflora.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.323-330
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• 2019

The purpose of this study was to investigate the effect of body mass index(BMI) and waist circumference(WC) on hemoglobin(Hb) in Korean Adult. This study analyzed the data of 2015, The Sixth KNHANES. Data were analyzed using descriptive statistics, t-test, ANOVA and Scheffe's test, Pearson correlation coefficient and multivariate logistic regression analysis(SPSS 25.0). The major findings, The subject's Hb In BMI, obese was the highest(F=97.862, p<0.001). The Hb In WC, $WC{\geq}90cm$ was higher for male(t=4.909, p<0.001), and $WC{\geq}85cm$ was higher for female(t=5.088, p<0.001). Hb has a significant positive correlated with BMI(r=0.188, p<0.001), WC(r=0.298, p<0.001). In male, Hyperhemoglobinemia was 2.30 times(p<0.001) higher in obese and 1.81 times(p<0.001) higher in $WC{\geq}90cm$. In female, Hyperhemoglobinemia was 1.99 times(p=0.002) higher in overweight, 5.66 times(p<0.001) higher in obese, and 4.27 times(p<0.001) higher in $WC{\geq}85cm$. In conclusion, adult obesity prevention and management programs should include exercises, diets, and education, and exercise interventions specifically for eliminating abdominal obesity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.325-330
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• 2018

This study was carried out to assess the composting temperature effects on germination of curled dock and barnyard millet seeds. After the seeds wrapped in gauze were buried in the compost heap, the seeds were taken out under monitering the temperature for measuring germination rate at 1.5, 3, 10 and 20 days of composting. The germination rate of the seeds was directly related to the temperature of the compost heap regardless of the type of composting method. The seeds that buried in the compost for 1.5 days at a temperature of $60{\sim}70^{\circ}C$ were completely lost their germination ability. However, the germination rate of the seeds retained about 10% even after 20 days when compost temperature was below $51^{\circ}C$. Reulsting data suggests that, it is necessary to keep the compost temperature at least $55^{\circ}C$ for more than 3 days in order to suppress the germination of the seeds. On the other hand, if the temperature of the compost rises by $60{\sim}70^{\circ}C$, the seeds will lose their gemination ability with in 1.5 days. In conclusion, aerobic composting would be more effective in suppressing germination ability of curled dock seed and barnyard millet seeds.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.324-330
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• 2018

In accordance with the amendment of the Industrial Safety and Health Act of 2007, Korea completely prohibited the import, distribution and manufacture of asbestos like Europe and Japan. Accordingly, the current problem of asbestos is the safe maintenance and disposal of asbestos construction material, the disposal of asbestos, and the final disposal of asbestos building materials. In the past, Korea used 100,000 tons of asbestos every year, and the building materials using it exceeded 1 million tons per year. These asbestos building materials continued to be used until 2006, and the Ministry predicted that these materials would continue to be maintained until 2044. When the permeable hardening agent is applied to the asbestos building material installed in the pre-pretreatment step for the harmless treatment of the asbestos waste and the dismantling is carried out, the scattering of the asbestos is suppressed in the disassembling step, detoxification treatment conditions can be improved. Therefore, permeable hardeners should be stably penetrated into asbestos building materials. In this study, it is suggested that pre - pretreatment methods for the harmlessization of waste asbestos building materials with medium density level can be presented. In order to efficiently perform pre - treatment for chemical harmlessness in the future, the mixing ratio of permeable hardener and middle water Optimization is the most important factor.

• Journal of Mushroom
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• v.16 no.4
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• pp.324-330
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• 2018

The objective of this study was to evaluate antioxidant effect and tyrosinase inhibitory activity of white beech mushroom (Hypsizygus marmoreus) extracts. The white beech mushroom was extracted into hot water and methanol. Total polyphenol content was highest in the hot water extract ($8.4{\pm}3.27mg\;GAE/g$) compared to the methanol extract ($7.3{\pm}2.85mg\;GAE/g$). The flavonoids contents in hot water and methanol extracts were $3.8{\pm}3.81ug/mg$ and $2.5{\pm}1.95ug/mg$, respectively. The tyrosinase inhibitory activity of extract was increased in a dose dependent manner and tyrosinase inhibitory activity of extract (hot water extract, 69.72%; methanol extract, 52.67% at 40 mg/ml) was lower than those of positive control 2% arbutin (96%). The DPPH radical scavenging activity of the hot water and methanol extract was 80% and 74%, respectively. Hot water extract ($63.34{\pm}1.00uM\;TE/g$) were more effective in ORAC (oxygen radical absorbance capacity) value than methanol extract ($46.33{\pm}0.48uM\;TE/g$). The toxicity of hot water and methanol extracts was investigated using WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulphonate) assay on the B16BL6 melanoma cells.

• Korean Journal of Medical Ethics
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• v.21 no.4
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• pp.330-343
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• 2018

This article explores some of the ethical issues associated with the fourth industrial revolution and suggests new directions for bioethics education in Korean universities. Some countries have recently developed guidelines and regulations based on the legal and ethical considerations of the benefits and social risks of new technologies associated with the fourth industrial revolution. Foreign universities have also created courses (both classroom and online) that deal with these issues and help to ensure that these new technologies are developed in an ethically appropriate fashion. In South Korea too there have been attempts to enhance bioethics education to meet the changing demands of society. However, bioethics education in Korea remains focused on traditional bioethical topics and largely neglects the ethical issues related to emerging technologies. Furthermore, Korean universities offer no online courses in bioethics and the classroom courses that do exist are generally treated as electives. In order to improve bioethics education in Korean universities, we suggest that (a) new course should be developed for interprofessional education; (b) courses in bioethics should be treated as required subjects gradually; (c) online courses should be prepared, and (d) universities should continually revise course contents in response to the development of new technologies.