• Journal of Christian Education in Korea
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• v.63
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• pp.39-64
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• 2020

COVID-19 is sweeping the world, and it is in crisis in all aspects of politics, economy, culture, and religion. As people experience the beginning and spread of COVID-19, wince and re-spread, the people are living in anxiety and depression. Because of the COVOD-19 crisis, Korean churches were unable to provide on-site worship, and online worship began, and churches that started on-site worship also performed online worship. In the case of church schools, the functions of fellowship and education were paralyzed and many are offering online Sunday service only. Many people eagerly want to go back to what it was before COVID-19, but it seems difficult because COVID-19 has become a global issue and a pandemic situation. We can't wait to get better out of this. In the COVID-19 crisis, the church was unable to properly handle the church's original work and to fully fulfill the mission of education. The response of many churches was to postpone the planned ministry to the second half of 2020. Now, we should try to set a new direction and prepare specifically to move in the new direction. With this perspective, this paper studied the direction of Christian education in the post COVID-19. Specifically, the theoretical basis of the direction of Christian education in the post COVID-19 was found in the theory of Agape's encounter, Catechesis theory, and diakonia theory, and specific directions were suggested according to these theories. Specifically, based on the theory of Agape's encounter, Christian education that emphasizes the encounter with the natural environment, Christian education that emphasizes the encounter among family members, Christian education that emphasizes the encounter among citizens of the world, and Christian education that emphasizes the encounter through online were presented. Based on the Catechesis theory, Christian education copping with the attack of heresy was presented. Finally, based on the diakonia theory, Christian education of service for society and Christian education of service based on data were presented.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.524-533
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• 2008

Industrial wastewater generated in the electroplating and metal finishing industries typically contain toxic free and complex metal cyanide with various heavy metals. Alkaline chlorination, the normal treatment method destroys only free cyanide, not complex metal cyanide. A novel treatment method has been developed which destroys both free and complex metal cyanide as compared with Practical Plant(I). Prior to the removal of complex metal cyanide by Fe/Zn coprecipitation and removal of others(Cu, Ni), Chromium is reduced from the hexavalent to the trivalent form by Sodium bisulfite(NaHSO$_3$), followed by alkaline-chlorination for the cyanide destruction. The maximum removal efficiency of chromium by reduction was found to be 99.92% under pH 2.0, ORP 250 mV for 0.5 hours. The removal efficiency of complex metal cyanide was max. 98.24%(residual CN: 4.50 mg/L) in pH 9.5, 240 rpm with 3.0 $\times$ 10$^{-4}$ mol of FeSO$_4$/ZnCl$_2$ for 0.5 hours. The removal efficiency of Cu, Ni using both hydroxide and sulfide precipitation was found to be max. 99.9% as Cu in 3.0 mol of Na$_2$S and 93.86% as Ni in 4.0 mol of Na$_2$S under pH 9.0$\sim$10.0, 240 rpm for 0.5 hours. The concentration of residual CN by alkaline-chlorination was 0.21 mg/L(removal efficiencies: 95.33%) under the following conditions; 1st Oxidation : pH 10.0, ORP 350 mV, reaction time 0.5 hours, 2nd Oxidation : pH 8.0, ORP 650 mV, reaction time 0.5 hours. It is important to note that the removal of free and complex metal cyanide from the electroplating wastewater should be employed by chromium reduction, Fe/Zn coprecipitation and, sulfide precipitation, followed by alkaline-chlorination for the Korean permissible limit of wastewater discharge, where the better results could be found as compared to the preceding paper as indicated in practical treatment(I).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.1
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• pp.65-72
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• 2008

The purpose of the HLW deep geological disposal is to isolate and to delay the radioactive material release to human beings and the environment for a long time so that the toxicity does not affect to the environment. The main requirements for the HLW repository design is to keep the buffer temperature below $100\;^{\circ}C$ in order to maintain its integrity. So the cooling time of spent fuels discharged from the nuclear power plant is the key consideration factors for efficiency and economic feasibility of the repository. The disposal tunnel/disposal hole spacing, the disposal area and thermal capacity required for the deep geological repository layout which satisfies the temperature requirement of the disposal system is analyzed to set the optimized spent fuels cooling time. To do this, based on the reference disposal concept, thermal stability analyses of the disposal system have been performed and the derived results have been compared by setting the spent fuels cooling time and the disposal tunnel/disposal hole spacing in various ways. From these results, desirable spent fuels cooling time in view of disposal area is derived. The results shows that the time reaching the maximum temperature within the design limit of the temperature in the disposal site is likely shortened as the cooling time of spent fuels becomes short. Also it seems that the temperature-rising and-dropping patterns in the disposal site are of smoothly varying form as the cooling time of spent fuels becomes long. In addition, it is revealed that a desirable cooling time of spent fuels is approximately 40-50 years when spent fuels are supposedly disposed in the deep geological disposal site with its structural scale under consideration in this study.

• Journal of The Korean Society of Grassland and Forage Science
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• v.3 no.1
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• pp.17-25
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• 1982

To clarify the direct effect of potassium and interactions with nitrogen and phosphorus on the yield of pasture plants, fertilizer experiment with varied levels of potassium and nitrogen treatment to grass single seeding, legume single seeding and grass-legume mixed seeding, was conducted for three years from 1977 to 1980. The summary of obtained experimental result may be described as below: 1. Potassium application, at any level of amount, did not show its effect to the establishment of plant population, however potash application responded to help winter hardiness at grass single seeding plot. 2. Potassium effect on the fresh yield at grass single seeding was distinct however, not clear effect was observed at legume single seeding and grass-legume mixed seeding plots. 3. For drymatter yield, the highest yield at legume single seeding was recorded 1.152 Kilograms per 10a are at treatment #4 and the highest yields of grass-legume mixed seeding and grass were recorded 1,093 kilograms (Treatment #3) and 834 kilograms (Treatment #5) respectively. 4. In observation of plant succession, they were found that orchardgrass and tall fescue have increased at grass single seeding plot and Alfalfa was dominant over 90 per cent of plant population at legume single seeding and grass-legume mixed seeding plots. It seems that potash effect was distinct in increasing orchardgrass population. 5. The results of this experiment shown that the maximum yield from grass single seeding was obtained at the plat where applied 20-20-30 kg/10a, $N-P_2O_5-K_2O$ and the maximum yield from legume single seeding was obtained at the plot applied with 8-20-20 kg/10a, $N-P_2O_5-K_2O$. 6. Fertilizer cost for producing one kilogram of dry matter in this experiment was lowest at treatment #1 of grass-legume mixed seeding and highest at treatment #5 of grass single seeding. The largest gross income was obtained from the plots where phosphate application was omitted. 7. From the results of this experiment, it may be recommended that economically optimum fertilizer application for grass single seeding will be 20-20-20- kg/10a, $N-P_2O_5-K_2O$ and for legume single seeding and grass-legume mixed seeding will be 8-20-20 kg/10a, $N-P_2O_5-K_2O$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.150-159
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• 2008

The marine litter generated as by-products of human activities and economic development enters to the sea through rivers or stream Indirectly, and through sea-based activities directly. It is commonly comprised of materials that degrade very slowly, such as various plastic products, polystyrene, glass, rubber, metal, wood, derelict fishing nets, wire, rope and so on. Such litter is found in the water column and on the seafloor as well as coastal areas In the Northwest Pacific region. It causes injury or death of human and other living organisms and also accident or damage of the vessel. It is not only a problem of country but also regional and/or global problem because it is transported by currents and winds from one country to another. In this regard, Northwest Pacific Action Plan (NOWPAP) Marine Litter Activity (MALITA) project had been carried out during 2006-2007 biennium and NOWPAP Regional Action Plan on Marine Litter (RAP MALI) has been also continuously implemented in the 2008-2009 biennium as next phase step of MALITA. MERRAC, one of four Regional Activity Centres (RACs) of NOWPAP, has developed monitoring guidelines, sectoral guidelines, and brochures related to sea-based marine litter and port reception facilities and services through MALITA project. Based upon these output, MERRAC will continuously implement relevant activities of RAP MALI in order to help to establish and improve a regional mechanism to deal with the sea-based marine litter problem. This paper aims to introduce MERRAC activities under MALITA and RAP MALI, and to suggest several recommendations to reduce marine litter in the NOWPAP region.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.99-110
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• 2016

Purpose: The current study was conducted in order to identify health and nutritional status of Korean underweight women in their twenties by comparing with normal, overweight, and obese women. Methods: Data from the 2010~2012 Korea National Health and Nutrition Examination Survey were used in this study. Subjects were 897 women aged 20~29 years. Subjects were classified according to underweight, normal weight, overweight, and obese groups based on body mass index. Health status was assessed using data from the health questionnaire and examination. Nutritional status was assessed using data from 24-hour dietary recall and a food frequency questionnaire. Results: The underweight group had higher education and exercised less than the obese group. Means of blood chemistry and blood pressure of the underweight group did not differ from those of the normal weight group. Means of fasting glucose, insulin, lipid profiles, blood cell counts, and blood pressure in the underweight group were different from those of the overweight or obese group. Proportions of delivery, breast feeding, and irregular menstruation in the underweight group were lower compared with the other groups. Except retinol intake, means of nutrient intake did not differ among four groups. There were significant differences among four groups in the intakes of cereals and eggs and frequency of consumption of dairy products. Conclusion: The current findings showed that health and nutritional status of underweight women in their twenties did not differ from those of normal weight women. In particular, health status of underweight women in their twenties was better than that of obese women of the same ages. Further study on health and nutritional status of extremely underweight women is necessary.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.37-49
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• 1991

This study was conducted to estimate the effects of year, age of dam at calving, farm and lactation period on milk yield with the data of 4,008 cows' records which were collected at 32 farms by Korea Animal Improvement Association from 1985 to 1989. The results obtained in this study are summarized as follows: 1. The average performance of the dairy cattle in the study were $5,959.23{\pm}2,113.03kg$ in actual milk yield, $49.19{\pm}22.77$ months in age of dam at calving, $27.11{\pm}5.13$ months in age at first calving and $255.11{\pm}79.68$ days in lactation period. 2. The percentages of variance component for different sources were 29.39% for the residuals, 1.91% for years, 4.86% for age at calving, 8.89% for farms and 54.94% for lactation period. 3. The overall mean of least-square estimate on the milk yield was 6,229.31kg. In the effects of year, the least-square means of milk yield were estimated 6,000.76kg in 1985-1987, 6,028.11kg in 1988 and 6,659.07kg in 1989. 4. The least-square means of calving age on the milk yield were estimated 5,456.01kg in less than 24 months, 6,565.48kg in 61-66 months which were the highest least-square means. This effects were gradually increased until the 61-66months and gradually decreased after the 61-66months, with highly significant differences among different months of age at calving(p<0.01). 5. In the effects of farm, the least-square means of milk yield were estimated 4,959.50 kg in the lowest farm and 7,497.07kg in the highest farm. Among the milk yield of each farm the effects showed highly significant difference(p<0.01). 6. The least-square means of milk yield in the effects of lactation period were gradually increased with the lapse of the lactation period. Among the lactation period the effects showed highly significant difference(p<0.01).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.63-68
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• 2018

The establishment of Ground Control Points (GCPs) in UAV-Photogrammetry is a working process that requires the most time and expenditure. Recently, the rapid developments of navigation sensors and communication technologies have enabled Unmanned Aerial Vehicles (UAVs) to conduct photogrammetric mapping without using GCP because of the availability of new methods such as RTK (Real Time Kinematic) and PPK (Post Processed Kinematic) technology. In this study, an experiment was conducted to evaluate the potential of RTK-UAV mapping with no GCPs compared to that of non RTK-UAV mapping. The positioning accuracy results produced by images obtained simultaneously from the two different types of UAVs were compared and analyzed. One was a RTK-UAV without GCPs and the other was a non RTK-UAV with different numbers of GCPs. The images were taken with a Canon IXUS 127 camera (focal length 4.3mm, pixel size $1.3{\mu}m$) at a flying height of approximately 160m, corresponding to a nominal GSD of approximately 4.7cm. As a result, the RMSE (planimetric/vertical) of positional accuracy according to the number of GCPs by the non-RTK method was 4.8cm/8.2cm with 5 GCPs, 5.4cm/10.3cm with 4 GCPs, and 6.2cm/12.0cm with 3 GCPs. In the case of non RTK-UAV photogrammetry with no GCP, the positioning accuracy was decreased greatly to approximately 112.9 cm and 204.6 cm in the horizontal and vertical coordinates, respectively. On the other hand, in the case of the RTK method with no ground control point, the errors in the planimetric and vertical position coordinates were reduced remarkably to 13.1cm and 15.7cm, respectively, compared to the non-RTK method. Overall, UAV photogrammetry supported by RTK-GPS technology, enabling precise positioning without a control point, is expected to be useful in the field of spatial information in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.2
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• pp.39-42
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• 1972

A field experiment was conducted in a moderately well drained paddy field doveloped in a narrow strip of a valley in order to observe changes of potassium requirement in paddy production when lime is applied. The results obtained are as follows; 1. The response of paddy to potassium (K) and lime (L) is represented mathematically as follow; $Y=462.78+11.582K-0.058L-0.768K^2-0.000015L^2+0.2204KL$. It is considered that the increase of potassium reqirement when slaked lime is applied, is partially due to the increased growth of plant accomplished by the improvement of soil conditions such as the reduction of respiration inhibitors and cationic balance in soil solution. 2. An economic analysis of the use of potassium and slaked lime applying the costs, 80 won per kg of paddy, 19 won per kg of potassium and 4 won per kg of slaked lime to the response function above, showed that the slaked lime without potssium brought a large loss, whereas the use of the lime together with potassium increased the profit remarkably. The profit increased when 10kg of potassium per 10 a is applied in addition to 200kg slaked limn, per 10kg is amounted 4,685 won. 3. A linear relationship between the economic optimum dose of potassium (y) and the amount of slaked lime (x) in paddy production, is obtained as follow; $$y=7.48+\frac{2.77}{200}x$$ It is, however, considered that the amount of potassium to he used might differ according to the soil conditions such as the potassium content and cation exchange capicity of the soil.

• Journal of dental hygiene science
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• v.16 no.3
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• pp.217-224
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• 2016

The aim of this study was to evaluate whether the number of existing permanent teeth is associated with chronic obstructive pulmonary disease (COPD) in a representative sample of Korean adults. Data from 3,107 subjects who participated in the 2009 Korea National Health and Nutrition Examination Survey were examined. The dependent variable was COPD and the independent variable was the number of existing permanent teeth. Spirometry results were classified into three groups (normal pattern, restrictive pattern, and obstructive pattern) by trained technicians. We used dichotomized COPD variables (no vs. yes). The number of existing permanent teeth was evaluated by oral examination and divided into 3 groups (0~19, 20~27, and 28). Demographic factors (age group and sex group), socioeconomic status (education and income), health behaviors (smoking and drinking), oral health and behavior (frequency of toothbrushing; periodontitis; decayed, missing, filled, permanent teeth index; and denture status), and general health status (body mass index, diabetes mellitus, and hypertension) were included as confounders in the analysis. Bivariate analysis and multivariate logistic regression analyses including confounders were applied, and all analyses considered a complex sampling design. Stratified analysis was performed by smoking status. After controlling for various confounders, there was a significant association between the number of existing permanent teeth and COPD (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.20~3.00 for the 20~27 group; OR, 3.93; 95% CI, 1.75~8.84 for the 0~19 group). The association was more significant in current smokers (OR, 8.90; 95% CI, 2.53~31.33). Our data indicate that the number of existing permanent teeth was independently associated with COPD, especially in current smokers. Further longitudinal research is needed to determine whether oral health promotion plays a role in the improvement of lung function and prevention of COPD.