• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.134-140
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• 2007

The purpose of this study is to investigate the landscape image and visual preference for ridges of the Seongpanak district at Mt. Hallasan. For this, the evaluation of the artificial and natural landscape is compared through the medium of color slides. Data is analyzed through the descriptive statistics and spatial image is analyzed by factor analysis algorithm. Principle component analysis and Varimax Method are applied to extraction and factor rotation respectively. The results of this study can be summarized as follows : General visual imagesthe Seongpanak district at Mt. Hallasan are clean, beautiful and attractive. The degree of visual preference increased commensurately with the lower rate of artificial factors. Landscape Factors covering the spatial image are found to be 'aesthetic value', 'spatial scale', 'natural quality', and 'topography' factor, which account for 57.6% of the total variants. The aesthetic value variable is the most important factor in visual preference and the unnatural factors are found to present negative elements with visual preference.

• Journal of Korean Public Health Nursing
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• v.14 no.2
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• pp.281-292
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• 2000

This study was conducted from Nov. 15 to Dec. 20. 1999, covering 3.214 fourth. fifth, and sixth graders in 25 schools. one from each Ku in Seoul. in order to provide basic data for developing smoking prevention program. The results of the study were as follows : 1. Among the students under inquiry. $10.2\%$ answered they had the experience of smoking, while $6.3\%$ said they are current smokers. 2. With regard to smokers' smoking behavior. about 90% of them smoke one or two cigarettes a day. A lot of them was their own or friends' homes to smoke. but not at specific time. Many students who smoke say they was cigarettes stored and/or picked up at home. $28.9\%$ of them have friends who know that they smoke and $27.7\%$ of them have siblings are aware they are smokers. $24.2\%$ of them said no one around them is aware of the fact they. smoke. 3. Forth grade is the most frequent year students start smoking$(23.5\%)$. Most of them had their first smoking experience at their homes out of curiosity. 4. Profile of a typical smoker would; be male; from miscellaneous religions; have very few friends: have hard time to fit in at school and he/she has a poor academic record. 5. Environmental profile of a smoker consists of: commercial area resident: single-parented; lacks attention from parents; has hard time at home; has someone who smokes within the family. 6. Regarding the experience of smoking prevention education. the rate of current smokers who have learned about smoking prevention was lower than that of who have not learned. 7. Among the non-smoking students. $81.3\%$ of them said they would keep away from smoking and $1.6\%$ of them said they would like to smoke in the future. while $17.1\%$ were undecided. Among the students who smoke. $93.7\%$ wish to quit smoking.

• Journal of the Korean Society for information Management
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• v.27 no.2
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• pp.129-155
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• 2010

In recent years, the changes in information technology have been so dramatic and the rate of changes has increased so much that information science research rigorously evolves with the passage of time and proliferates in diverging research directions dynamically. The aims of this study are to provide a global overview of research trends in information science and to trace its changes in the main topics over time. The study examined the topics of research articles published in JASIST between 1985 and 2009 and identified its changes during five 5 year periods. The study found that the most productive area has consistently been 'Information Retrieval', followed by 'Informetrics', 'Information Use and Users', 'Network and Technology', and 'Publishing and Services'. Information retrieval is a predominant core area in Information Science covering computer-based handling of multimedia information, employment of new semantic methods from other disciplines, and mass information handling on virtual environments. Currently Informetric studies shift from finding existing phenomena to seeking valuable descriptive results and researchers of information use have concentrated especially on information-seeking aspects, so adding greater sophistication to the relatively simple approach taken in information retrieval.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.94-103
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• 2016

For elevated railway station on which track is connected with superstructure of station, structural vibration level and structure-borne-noise level has exceeded the reference level due to structural characteristics which transmits vibration directly. Therefore, existing elevated railway station is in need of economical and effective vibration reduction method which enable train service without interruption. In this study, structural vibration non-transmissible system which is applied to vibroisolating material for column member is developed to reduce vibration. That system is cut covering material of the column section using water-jet method and is installed with vibroisolating material on cut section. To verify vibration reduction effect and structural performance for structural vibration non-transmissible system, impact hammer test and cyclic lateral load test are performed for 1/4 scale test specimens. It is observed that natural period which means vibration response characteristics is shifted, and damping ratio is increased about 15~30% which means that system is effective to reduce structural vibration through vibration test. Also load-displacement relation and stiffness change rate of the columns are examined, and it is shown that ductility and energy dissipation capacity is increased. From test results, it is found that vibration non-transmissible system which is applied to column member enable to maintains structural function.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.294-300
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• 2005

The effect of hairy vetch sod culture on reduction of soil loss and providing of nitrogen was investigated for the fields of Chinese cabbage in Hoenggye-Ri, Pyeongchang-Gun Gangwon-Do (780 m above sea level) from 2002 to 2003. Hairy vetch was sowed at just before planting, 15, 30 and 40 days after planting and right after harvest of Chinese cabbage. Hairy vetch was sod-cultivated with Chinese cabbage. The amount of sowing was $40kg\;10a^{-1}$. In this experiment, proper sowing times that had no influence on the yield of Chinese cabbage were 30 and 40 days after planting while other sowing times led to decrease the yield. In case of the former, there was 74% reduction effect of soil loss compared with no-hairy vetch because of covering the fields with hairy vetch right after harvest. Moreover, when the hairy vetch was put into the soil before planting of Chinese cabbage in the next year, it showed 61-79% substitution effect of standard application rate ($320kg\;ha^{-1}$, chemical fertilizer) for nitrogen fertilizer. It is suggested that using hairy vetch as cover crop would be useful in conservation of soil loss and reduction input of agricultural materials.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.154-160
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• 1998

This study was conducted to develop a foliar applied herbicide mixture covering wide spectrum weeds in dry direct seeded rice. Uniform precision central composite design(UPCCD) was employed to evaluate the effect of herbicide mixture among cyhalofop-butyl(cyhalofop), bispyribenzoxim and pyrazosulfuron-ethyl(pyrazosulfuron) having different weed control spectrum and to determine the best application rates of the three herbicide mixtures. The partial additive effect was observed in the mixture of cyhalofop and bispyribenzoxim with pyrazosulfron against Echinochloa crus-galli Beauv var crus-galli L., attributed to the negative interaction between cyhalofop and bispyribenzoxim system. Additive effect was observed in the mixture of bispyribenzoxim and pyrazosulfuron against Cyperus serotinus R. and Aneilema keisak H. but cyhalofop had no effect on these weeds. The most appropriate rate of the mixture of cyhalofop with bispyribenzoxim and pyrazosulfuron was 100 : 12 : 10g ai/ha exhibiting $ED_{90}$ against three weeds such as E. crus-galli, C. serotinus and A. keisak.

• Korean Journal of Comparative Education
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• v.27 no.1
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• pp.247-284
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• 2017

The purpose of this study is to analyze firm's motivation of participating and investing in apprenticeship in Germany and Korea, and to investigate institutional factors influencing firm's motivation. By comparing institutional factors of the two countries, it aims to drawing out policy implications for improving Korean apprenticeship. The main method for data collection was comprehensive literature review on international organizations, each countries' government and research institutes' policy materials, statistical data, research outputs and media resources related to each countries' apprenticeship. Considering whether firm's motivation for participating and investing in apprenticeship is production-oriented or investment-oriented, Germany is more inclined to investment motivation with firm's covering net cost during apprenticeship period. On the other hand, Korea is more inclined toward production orientation with firm's expectation of gaining net profit during the training period. Why is firm's training motivation different in these two countries? The author tried to find the reason from the difference of institutional factors of the countries by dividing institutional factors into 4 categories: context(tripartite relations, legal framework), input (flexibility of the system, government incentive), process(training contents, training duration, quality assurance), and output(completion/retention rate, apprentice's productivity). The key implication from the comparative analysis of institutional factors is that it is necessary to enforce companies to have "accountability" on the minimum critical elements, but also to ensure them to have "autonomy" on the rest of the elements.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.345-364
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• 2021

Developments in the understanding of fire behaviour for large open-plan spaces typical of tall buildings have been greatly outpaced by the rate at which these buildings are being constructed and their characteristics changed. Numerous high-profile fire-induced failures have highlighted the inadequacy of existing tools and standards for fire engineering when applied to highly-optimised modern tall buildings. With the continued increase in height and complexity of tall buildings, the risk to the occupants from fire-induced structural collapse increases, thus understanding the performance of complex structural systems under fire exposure is imperative. Therefore, an accurate representation of the design fire for open-plan compartments is required for the purposes of design. This will allow for knowledge-driven, quantifiable factors of safety to be used in the design of highly optimised modern tall buildings. In this paper, we review the state-of-the-art experimental research on large open-plan compartment fires from the past three decades. We have assimilated results collected from 37 large-scale compartment fire experiments of the open-plan type conducted from 1993 to 2019, covering a range of compartment and fuel characteristics. Spatial and temporal distributions of the heat fluxes imposed on compartment ceilings are estimated from the data. The complexity of the compartment fire dynamics is highlighted by the large differences in the data collected, which currently complicates the development of engineering tools based on physical models. Despite the large variability, this analysis shows that the orders of magnitude of the thermal exposure are defined by the ratio of flame spread and burnout front velocities (V_S / V_BO), which enables the grouping of open-plan compartment fires into three distinct modes of fire spread. Each mode is found to exhibit a characteristic order of magnitude and temporal distribution of thermal exposure. The results show that the magnitude of the thermal exposure for each mode are not consistent with existing performance-based design models, nevertheless, our analysis offers a new pathway for defining thermal exposure from realistic fire scenarios in large open-plan compartments.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.731-743
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• 2018

This study was conducted to evaluate the effects of green manures and complemental fertilization with oil cake or liquid fertilizer on growth and nitrogen use efficiency of Chinese cabbage cultivated in organi systems. Field experiments were carried out at the National Institute of Agricultural Science in Suwon, South Korea from 2012 to 2014. Two green manure crops, Crotalaria and Hairy vetch, was cultivated in summer and in winter, respectively. The application methods of the green manure consisted of three tillage systems (overall tillage, partial tillage and no tillage). Oil cake and liquid fertilizer were used as complemental fertilizer. The results showed that when used as covering material in the upland soil without tillage, green manure fertilization was more effective in increasing growth and yield of Chinese cabbage than when incorporated into soil. It was possible to grow and harvest Chinese cabbage in the spring season by the application of hairy vetch as winter green manure. The higher yield of Chinese cabbage with green manure application was caused by the lower incidence rate of soft rot and tip-burn. The yield of the Chines cabbage that received green manure applications over two consecutive seasons followed by the supplemental fertilization with oil cake was similar to that of the conventional chemical fertilization. Following a single season green manure application in summer, however, the yield of cabbage was only about 70% of the conventional treatment. Green manure cultivation with additional liquid fertilization produced a yield similar to the conventional fertilization treatment, soil inorganic nitrogen concentration remained stable and the nitrogen use efficiency increased in the green manure applied soil. In conclusion, the organic cultivation of Chinese cabbage in the autumn season could be outperformed in the upland soil receiving two seasons (winter and summer) of green manure fertilization followed by the supplemental fertilization with liquid fertilizer.

• Korean Journal of Medicinal Crop Science
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• v.27 no.4
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• pp.284-291
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• 2019

Background: Ginseng root rot disease, caused by Cylindrocarpon destructans and Fusarium solani is a major cause of replant failure in continuous cropping ginseng. Methods and Results: To control replant injury in soil infected with C. destructans and F. solani, biosolarization was performed by covering the plot with transparent polyethylene film after adding green manure of maize and sunflower for the summer season. Per 10 a, fresh and dry weight of maize was 10.1 and 2.5 tons, respectively, and that of sunflower was 8.1 tons and 1.2 tons, respectively. Mean maximum temperature at 20 cm depth was $33.2^{\circ}C$, $41.5^{\circ}C$ and $41.8^{\circ}C$ in the control, maize-incorporated and sunflower-incorporated plots, respectively. The elapsed time over $40^{\circ}C$ was 36.4 h in the maize-incorporated plot and 77.3 h in the sunflower-incorporated plot. Biosolarization increased $NO_3$ content in soil, while content of organic matter, Ca, and Mg was decreased. Electrical conductivity, $NO_3$ and $P_2O_5$ in soil significantly increased after two years of biosolarization. The number of spores of C. destructans in soil was significantly decreased by biosolarization, and sunflower treatment was more effective than maize treatment in decreasing the number of spores. Root yield of 3-year-old ginseng was significantly increased by biosolarization, however, there was no significant difference between maize and sunflower treatments. Rate of root rot in 3-year-old ginseng decreased to 16.5% with the incorporation maize and 5.0% with the incorporation of sunflower, while that in control 25.6%. Conclusions: Biosolarization was effective in inhibiting ginseng root rot by decreasing the density of root rot disease and improving soil chemical properties.