• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.85-91
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• 1988

A field experiment was conducted to determine the effects of shading degrees (0: full sunlight, 25, 50 and 75%) on the proximate components, cell wall constituents (CWC), digestibility, water soluble carbohydrates (WSC) and nitrate nitrogen ($NO_3$-N) concentration of grasses grown in forest. For the test different artificial shading houses were established and pasture species used were orchardgrass, timothy, perennial ryegrass and ladino clover. The experiment was performed at LES in Suwon. 1985. 1. Considering proximate components, CWC and digestibility of grasses, ladino clover showed the best quality, and then perennial ryegrass. 2. The contents of crude protein, crude ash, and digestibility of grasses were increased with shading, regardless of pasture species. As the shading degrees are increased, the contents of crude fiber in orchardgrass, perennial ryegrass and timothy were decreased, while that in ladino clover was increased with shading. 3. Grasses grown in spring showed higher digestibility than those grown in summer season. 4. The content of WSC was the highest in perennial ryegrass, and then ladino clover, orchardgrass, and timothy, in that order. Also WSC was decreased as the shading degrees are increased. 5.The content of $NO_3$-N was the highest in perennial ryegrass, and then orchardgrass, ladino clover and timothy, in that order. Also the $NO_3$-N was significantly increased with higher shading level. In the regression equation between shading degrees and $NO_3$-N ($r^2$=0.90**, TEX>$r^2$=0.95**), shading degree of 43 to 44% was critical level, causing nitrate poisoning to animal. 6 Considering grass quality, dry matter yield and $NO_3$-N, less than 40% of shading degree (over 60% of full sunlight) was desirable for better grassland improvement, management and utilization in the forest.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.92-98
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• 1988

With a purpose of finding out the effects of magnesium and boron enriched organic-compound fertilizer application on the dry matter yield, yield components and changes in the botanical composition on the hilly pasture, a field experiment was arranged with five different treatments as a randomized block design and lasted from September, 1984 to the end of growing season in 1986. The results obtained are summarized as follows : 1. As a early plant growth and development, winter hardiness, growth vigour and coverage of grasses at the plots with organic-compound fertilizer application were better comparing to single dressing. 2. Average dry matter yields for two years were shown significantly high due to increasing amount of fertilizer. This trend was same both single and organic-compound fertilizer. And dry matter yields with organic-compound fertilizer application of low (8, 693.1 kg/ha) and conventional level (12, 758.7 kg/ha) were appeared to increase by 10 and 15% than those of single dressing of Low (7, 930.6 kg/ha) and conventional level (11, 122.6 kg/ha), respectively. But it was not significant difference. 3. Dry matter yield of grasses was significantly gained by increasing amount of fertilizer. The yield of legumes at the plot without fertilization was significant higher comparing to fertilizing plots, but it was not different between low and conventional dressing levels. However, at the plots with organic-compound fertilizer application the yields of grasses were a little more increased by 8-14%, and legumes were much more gained by 26-29% than those of the same species groups with single dressing, but it was not significant between the different kinds of fertilizer in the same fertilizing level. 4. At the grassland management, the rate of legumes tended to dominate at the plot without fertilization gradually. On the other hand, the botanical compositions and the rates of grasses were much better maintained at the plots with fertilization. But the rates of legumes with organic-compound fertilizer application tended to increase a little more than those of single dressing gradually.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.2
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• pp.101-108
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• 2007

The object of this experiment was to investigate the effect of mixture which consist of different seeding rates and species on dry matter yield and quality in Daejon area. The field trials were conducted from 2003 to 2005 at Chungnam National University in order to evaluate the dry matter yield and quality of different mixture. The experimental design includes three mixture types: Conventional mixtures, CM{orchardgrass(Potomac) 50% + tall fescue (Fawn)20% + Kentucky bluegrass(Kenblue) 20% + white clover(Regal) 10%}, red clover + mixtures, RM{orchardgrass(Potomac) 40% + tall fescue(Fawn) 20% + Kentucky bluegrass(Kenblue) 10% + red clover(Kenland) 30%) and Turf type grass + mixtures, TM {orchardgrass (Potomac) 50% + turf type grass (tall fescue, Millennium 20% + Kentucky bluegrass, Midnight 10% + perennial ryegrass, Palmer III 10%) + white clover(Regal) 10%}. The average DM yield for 2 years of red clover+mixture(11,656kg/ha) was higher than those of the other mixtures(p<0.05). The content of crude protein and dry manu digestibility were higher in red clover+mixture than in other mixtures(p<0.05). but, the content of fibrous compounds like as NDF, ADF, cellulose and lignin were lower in red clover+mixture than in other mixtures(p<0.05). The crude protein dry matter(CPDM) yield was higher in red clover + mixture(2,832kg/ha) than in conventional mixture(2,372kg/ha) and turf type + mixture(2,266kg/ha)(p<0.05). The digestible dry matter (DDM) yield was higher in red clover + mixture(8,881 kg/ha) than in conventional mixture(8,255kg/ha) and turf type + mixture(7,314kg/ha)(p<0.05). In botanical composition at last cutting time in 2005, conventional mixture were maintained orchardgrass 45%, tall fescue 22%, Kentucky bluegrass 5% and white clover 24%. Red clover + mixture were maintained orchardgrass 40%, tall fescue 22%, Kentucky bluegrass 4% and red clover 31%. turf type + mixture were orchardgrass 37%, tall fescue 23%, Kentucky bluegrass 6%, perennial ryegrass 8% and white clover 24%, respectively. As summary, DM yields and quality of mixture species and seeding rates were observed significant difference. The results of this experiment indicated that red clover + mixture was more effective in enhancing the DM yield and forage quality in Daejon area.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.537-544
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• 2017

Stable carbon isotope ratio of carbon dioxide (${\delta}^{13}C_{CO2}$) is used as an important indicator in the researches for global climate change and carbon capture and sequestration technology. The ${\delta}^{13}C$ value has been usually analyzed with Isotope Ratio Mass Spectrometer (IRMS). Recently, the use of Laser Absorption Spectrometry (LAS) is increasing because of the cost efficiency and field applicability. The purpose of this study was to suggest practical procedures to prepare laboratory reference gases for ${\delta}^{13}C_{CO2}$ analysis using LAS. $CO_2$ gas was adjusted to have the concentrations within the analytical range. Then, the concentration of $CO_2$ was assessed in a lab approved by the Korea Laboratory Accreditation Scheme and the ${\delta}^{13}C_{CO2}$ value was measured by IRMS. When the instrument ran over 12 hours, the ${\delta}^{13}C$ values were drifted up to ${\pm}10$‰ if the concentration of $CO_2$ was shifted up to 1.0% of relative standard deviation. Therefore, periodical investigation of analytical suitability and correction should be conducted. Because ${\delta}^{13}C_{CO2}$ showed the dependency on $CO_2$ concentration, we suggested the equation for calibrating the concentration effect. After calibration, ${\delta}^{13}C_{CO2}$ was well matched with the result of IRMS within ${\pm}0.52$‰.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.403-414
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• 2004

In the accompanying paper, we proposed a real. time volumetric imaging method using a cross array based on receive dynamic focusing and synthetic aperture focusing along lateral and elevational directions, respetively. But synthetic aperture methods using spherical waves are subject to beam spreading with increasing depth due to the wave diffraction phenomenon. Moreover, since the proposed method uses only one element for each transmission, it has a limited transmit power. To overcome these limitations, we propose a new real. time volumetric imaging method using cross arrays based on synthetic aperture technique with linear wave fronts. In the proposed method, linear wave fronts having different angles on the horizontal plane is transmitted successively from all transmit array elements. On receive, by employing the conventional dynamic focusing and synthetic aperture methods along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. Mathematical analysis and computer simulation results show that the proposed method can provide uniform elevational resolution over a large depth of field. Especially, since the new method can construct a volume image with a limited number of transmit receive events using a full transmit aperture, it is suitable for real-time 3D imaging with high transmit power and volume rate.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.236-244
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• 1999

A feasibility study was performed to examine the agronomic application of treated sewage on paddy rice culture by field experiment. The domestic sewage was treated by the constructed wetland system which was in subsurface flow type and consisted of sand and macrophyte. The effluent of the wetland system was adjusted to maintain the total nitrogen concentration below $25mgL^{-1}$ and used for irrigation water. Four treatments include (1) irrigation of treated sewage after concentration adjusted with conventional fertilization (TWCF), (2) irrigation of treated sewage after concentration adjusted with half of the conventional fertilization (TWHF), (3) irrigation of treated sewage after concentration adjusted without fertilization (TWNF), and (4) irrigation of treated sewage as it was without fertilization (SWNF). These cases were compared to the control case of tap water irrigation with conventional fertilization (Control). Generally, addition of the treated sewage to the irrigation water showed no adverse affect on paddy rice culture, and even improvement was noticed in both growth and yields. TWCF showed the best result and the yields exceed the Control in about 10%. Overall performance of the treatments was TWCF, Control, TWHF, TWNF, and SWNF in decreasing order. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale application, further study is recommended on the specific guidelines of major water quality components and public health.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.73-96
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• 2013

ICAO's Universal Safety Oversight Audit Programme (USOAP) was initially launched in January 1995, in response to widespread concerns about the adequacy of aviation safety oversight around the world. The recent reduction in aircraft accidents and effective role that is evaluated on the basis of these results, and in 2013 the existing 'snapshot approach' to 'regular monitoring system (USOAP-Continuous Monitoring Approach)' was converted to. ICAO aviation safety assessment of the state in today's international community 'aviation safety credibility' as objective indicators to judge the enormous impact on the aviation industry, the state is not satisfactory, especially if the results of the evaluation and expansion of code-share airline ban, reduced international air transit passengers, including premium increases business and economic penalties should. In addition, ICAO implementation of the existing laws and regulations(Prescriptive Approach), but based on the Risk-based prevention model, Proactive Approach introduced the concept of aviation safety system, including international aviation safety policy has been to switch paradigms. This new ICAO international aviation safety policy also applies to the Government of the Republic of Korea in line with the aviation safey policies have changed. In particular, the systematic implementation of safety management for the existing laws and regulations in the center of the safety oversight system of risk-based introduction of the concept of proactive safety management, and According to international standards ICAO aviation service providers operate their own Safety Management System was set out in Aviation Law ever. In addition, the aviation safety is at the center of the field of the safety of aircraft operations and maintenance for the promotion is promoting various safety policies. This new paradigm shift in the international aviation safety policy in line with our state in the international community with the most exemplary aviation safety system firmly established itself as a model, the Government will strengthen the competitiveness of our aviation plans to support. To do this, the government, airlines, aviation officials try all the practical effect would be expected.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.228-232
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• 2007

Slow-release fertilizers (SRF) have been used to reduce nutrient loss through increasing fertilizer efficiency and to save labor. Several SRFs were developed for rice plant in Korea, but there is few for horticultural crop plants. Two slow-release complex fertilizers, 100T and 150T, which made for controlling nitrogen release time up to 100 and 150 days, respectively, were selected for the incubation test cto evaluate nitrogen (N) release rate in soil. The N of urea selected as the control was completely released within a week after application. Sixty three and 53% of total N were released from 110T and 150T of slow release fertilizers within 8th weeks after application, respectively. For pepper cultivation CF110 and CF150, new slow-release complex fertilizer, were made of mixing 40% of conventional fertilizer and 60% of 110T and 150T, respectively, based on the amount of recommended fertilizer for pepper cultivation $(N-P_2O_5-K_2O=190-112-149\;kg\;ha^{-1})$, and were totally applied before pepper transplanting in the field as the basal fertilizer. Inorganic N $(NH_4^+-N+NO_3^--N)$ concentration in soil was higher in the CF110 treatment than in the control (NPK) at all period of pepper cultivation. In the CF150 treatment concentration of inorganic N in soil was low compared to control up to 8th weeks after transplanting. However, there was no difference in plant height and nutrient content of pepper leave between CF110 treatment and the control. In comparison, plant height was significantly lower in CF150 than the control and CF110 treatments. Around 4% of fresh pepper yield was increased in CF110 compared to the control, but it was decreased to about 2% by CF150 treatment. Conclusively, CF110 form could be recommended as a slow release fertilizer for pepper cultivation.

• Korea journal of population studies
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• v.21 no.2
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• pp.182-227
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• 1998

Korean government decided to adopt an explicit population control policy in 1961 and from the following year the establishment and operation of the national family planning programme was included in each of the Five-Year Economic Development Plans that began in 1962. This policy was pursued in the understanding that without proper population control measures korea could not be able to achieve economic development. Korean national family planning programme is characterized by contraceptive target system through public health network with distribution of free contraceptives by family planning field workers and clinical contraceptive services such as IUD, vasectomy and tubaligation at designated clinics by the government. In addition, IE&C activities by the Planned Parenthood Federation of Korea and programme evaluation and research by the Korea Institute for Health and Social Affairs contributed to the development of the government programme. Between 1960 and mid 1980s the nation's total fertility rate was reduced from 6.0 to population replacement level of 2.1 and thereafter it has been maintained at 1.6 to 1.7 of below replacement level. With a short period of less than three decades fertility transition was completed in Korea. It is estimated that if the current level of below replacement fertility continues, the population in Korea stabilize at around 52.78 million people by the year 2028, and it will begin to decrease thereafter. Under this circumstances, the government adopted new directions and strategies of the population policy in June 1996, focused primarily on population quality and social welfare than on demographic arenas. In spite of over 80 percent of high contraceptive prevalence among married women, high incidence of induced abortions is maintained. Moreover, the prevalence of sex selective induced abortions using procedures to determine the sex of the fetus has resulted in an imbalance in the sex ratio at birth. In order to overcome those problems associated with reproductive health new policy for population quality control and health promotion programme should be highly strengthened in the future.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.287-294
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• 2015

In this study, we investigated the antioxidative effects of brown seaweed Ecklonia cava extract and its subfractions. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction of E. cava. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of ethyl acetate fraction ($FSC_{50}=6.98{\mu}g/mL$) and aglycone fraction ($7.03{\mu}g/mL$) are similar to that of (+)-${\alpha}$-tocopherol ($8.98{\mu}g/mL$) which is a reference control. Reactive oxygen species (ROS) scavenging activity (total antioxidant capacity, $OSC_{50}$) of the aglycone fraction ($OSC_{50}=14.48{\mu}g/mL$) on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay was the strongest among all extract and fractions. However, all samples showed lower antioxidant activities than that of L-ascorbic acid ($6.88{\mu}g/mL$) known as a powerful antioxidant. The protective effect of 50% ethanol extract on the $^1O_2$-induced cellular damage of human erythrocytes was dependent on the concentration from 5 to $50{\mu}g/mL$. Both ethyl acetate fraction and aglycone fraction showed strong cellular protective activities at $10{\mu}g/mL$, where the cellular protective effects (${\tau}_{50}$) of each fraction were recorded 442.0 min and 539.9 min, respectively. Three kinds of extract/fractions of E. cava showed much greater cellular protective activities at $10{\mu}g/mL$ than that of liposoluble antioxidant (+)-${\alpha}$-tocopherol (40.6 min) which is a reference control. These results suggest E. cava extracts and its fractions can be applied as an antioxidant ingredient in a field of cosmetics.