• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.78-91
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• 2018

Sangjogam, located in Goseong, Gyeongsangnam-do, was designated as Natural Monument #411, because of its diverse geological heritage, such as fossils, ripple marks, dykes, and columnar joints. In the area, Byeongpungbawi, with its beautiful columnar joints vertical to the bedding plane of the underlying sedimentary rocks and spectacular coastal view, was named after its overall shape reminiscent of a huge folding screen. The purpose of this study was to investigate the formation process of the columnar joints using the anisotropy of magnetic susceptibility (AMS) method. AMS measurements showed that the k1 and k3 values representative of directions of the long and short axes of a magnetic particle at each point strongly clustered, and the oblate magnetic foliation structure in Byeongpungbawi developed during sill-type intrusion rather than lava flow. In summary, Byeongpungbawi was produced by sill-type intrusion along the bedding plane of the underlying sedimentary layer, and the subsequent formation of columnar joints was accompanied by the cooling and contraction of intruding rhyolite magma. This study potentially provides a basic research tool in understanding the formation mechanism of columnar joints which are widely distributed in southern Korea.

• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.49-60
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• 2021

We examined the flow characteristics by direct runoff and base flow in a headwater stream during observed 59 rainfall events of flood season (June~September) from 2017 to 2020 yrs. Total precipitation ranged from 5.0 to 400.8 mm, total runoff ranged from 0.1 to 176.5 mm, and runoff ratio ranged from 0.1 to 242.9% during the rainfall events. From hydrograph separation, flow duration in base flow (139.3 days) was tended to be longer than direct runoff (78.3 days), while the contribution of direct runoff in total runoff (54.2%) was greater than base flow (45.8%). The total amount and peak flow of direct runoff and base flow had the highest correlation (p<0.05) with total precipitation and duration of rain among rainfall and soil moisture conditions. Dominant rainfall events for the total amount and peak flow of base flow were generated under 5.0~200.4 and 10.5~110.5 mm in total precipitation. However, when direct runoff occurred as dominant rainfall events, total amount and peak flow were increased by 267.4~400.8 and 169.0~400.8 mm in total precipitation. Therefore, the unique aspects of our study design permitted us to draw inferences about flow characteristic analysis with the contribution of base flow and/or direct runoff in the total runoff in a headwater stream. Furthermore, it will be useful for the long-term strategy of effective water management for integrated surface-groundwater in the forested headwater stream.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.147-157
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• 2023

Centella asiatica extract is widely used as a raw material for cosmetics due to its various effects, but it is difficult to expect penetration into the skin due to its high molecular weight and low solubility. In order to solve these problems, lipid-based liposomes of various types were developed to increase skin absorption. Therefore, in this study, we tried to increase the skin absorption rate by preparing transfersomes using surfactants as edge activators in existing liposomes. Liposome and transfersomes containing Span 80 and Tween 20, 60, 80, and 85, respectively, were prepared using a high-pressure homogenizer, and we evaluated the particle size, polydispersity index, zeta potential, and skin absorption rate. As a result, there was almost no change in the physical properties of particle size, polydispersity index and zeta potential from 25 ℃ to 60 d, and the particle size of transfersomes containing Tween 20, 60, and 80 increased after 60 d at 45 ℃. Madecassoside, main substances of the Centella asiatica extract was used as an standard and madecassoside was measured and calculated when measuring the skin absorption rate using Franz diffusion cells. As a result, formulations containing Tween 20 were the most, whereas formulations containing Span 80 were the least. According to the skin absorption coefficient (Kp) value, all formulations showed 'very fast', and the absorption rate was similar or greater than that of liposomes, except for formulations containing Span 80. Through this, it was confirmed that the larger the HLB value of the nonionic surfactant, the smaller the particle size of the transfersome, and the increased skin absorption rate due to the increased flexibility of the vesicle membrane. Through this study, transfersome using surfactant as an edge activator can be expected to solve local skin problems not only as a cosmetic raw material or product, but also by increasing skin absorption.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.175-184
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• 2016

In this study, we transplanted Chinese (Liaoning Dandong) and Chungnam (Taean) manila clam seeds to Gochang tidal flats in Jeonbuk province, and compared growth, mortality, and condition indices from May 2015 to August 2016. Within 2 months after transplantation, clam mortality of Chungnam and Chinese origin were $6.9{\pm}4.3%$, $16.9{\pm}7.9{\sim}21.0{\pm}6.3%$, respectively. We supposed that higher mortality of Chinese manila clams might be due to higher stress and weakening of physiological functions by air-exposure and unavailability of food intake for 5 days harvesting, transportation, quarantine procedures. Unlike the local clam farmer's opinion based on their field experience, growth of Chungnam clams in shell length and total weight were a little better than Chinese without statistical significant difference (P > 0.05). Condition indices of Chinese clams showed declining tendency after reaching a peak in May 2014, and in June 2015, respectively. Meanwhile, Chungnam clams has reached its peak of condition indices in May 2014 and in April 2015, respectively. From this result, we supposed that there might be at least one month difference in reproduction between the Chinese and Chungnam manila clams during the first-transplanted year. Because the mortality of adult clam have sharply increased from June 2015 (due to high temperature, few rainfall and spawning) in Gochang tidal flat, it would be recommendable that farmers harvest the clams before June when its shell length are larger than 40 mm. In conclusion, we could directly compare the productivity of Chinese and Chungnam manila clam at Gochang tidal flats by field experiment, and these results are also meaningful to manila clam farmers.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.6
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• pp.66-80
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• 2009

This paper attempts to investigate how the cultural phenomena associated with 'Wuyi-Doga(武夷棹歌)' and 'Wuyi-Gugok (武夷九曲)' was introduced to Joseon. The icon and code of 'Gugok' cultural text which was observed in the process of transmitting the culture through repetition and imitation were examined. With regard to research methodology, an 'analysis and discussion framework' was designed based on the literature review, field survey and the seven textuality criteria proposed by Dressier. Then the textuality of 'Wuyi-Gugok' was analyzed in terms of the dependent relation of text, the relationship between the creator and user, repetition, imitation and the spread process. Since ZhouHee(朱熙)'s 'Wuyi-Doga' and 'Wuyi-Gugok' were introduced to Joseon through literature and paintings, they became a part of the cultural Phenomena with unprecedented popularity. As a result, a great number of imitations can be found. In addition, governors would even take care of political affairs in a scenic mountain valley as described in this literature. Regardless of the writer's intentiot 'Gugok' settled in Joseon as new culture in harmony with Taoism and Sung COnfucianism. In other words, Joseon's Gugok-Wonlim(九曲園林) accepted the nature-appreciation aesthetic consciousness in 'Wuyi-Doga' and 'Wuyi-Gugok' on the basis of Taoism and Sung Confucianism. In terms of the text-based dependent relation only, however, the geographical coherence was somewhat loosened while the Gugok Culture that was dependent on Taoism or elegance in life dominated the internal structure of the textuality. Meantime, the internal factors that dominated the textuality of 'Wdyi-Gugok' were interpreted as 1) 'Aesthetics of Bending, Water Whirls', 2) 'Territoriality Expression Carve letters,' 3) 'Cultural Landscape seeing through the Speculation of Meaning,' 4) 'The Pursuit of Oddness and Presentationism' and 5) 'Transcendental Landscape of Taoism and Topos.'

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.4
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• pp.29-41
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• 2015

Abandoned paddy field provides an excellent opportunity to improve the species diversity and habitat quality. Ecological characteristic on the changing of plant communities at different seral stages is a major basis data for ecological restoration. In this study, we investigated changes of the species composition and community indices on the plant community associated with abandonment of cultivated rice paddies. The ecological stability of the habitat was evaluated by using eco-floristic characters(Di; Disturbance index, AUI; Actual urbanization index). Survey sites were grouped into six stages(stageI (${\leq}3years$), stageII(3-5years), stageIII(5-7years), stageIV(7-10years), stageV(10-15years), stageVI(${\geq}20years$). Vegetation investigation was done from May 2009 to October 2012 and carried out phytosociological approach. The total flora were summarized as 176 taxa including 58 families, 127 genera, 157 species, 3 subspecies, 15 varieties and 1 forms. At each of successional stages, 64 taxa in stage I, 34 taxa in stage II, 84 taxa in stage III, 83 taxa in stage IV, 92 taxa in stage V, 23 taxa in stage VI were identified. Of the occurrence plants, the species with the highest r-NCD value were Alopecurus aequalis, Juncus effuusus var. decipiens, Persicaria thunbergii, Artemisia princeps, Salix koreensis and Alnus japonica at each stages. Herbaceous annual plants were dominated in the early stage, but its r-NCD value declined in the middle stage and the late stage. On the other hand, herbaceous perennial plants and Persicaria thunbergii, annual hydrophytes, increases in the middle stage. Woody plant and herbaceous plant which appeared in the forest edge increases in the late stage. Community indices correlate with successional stages. Richness and diversity index increase along the successional gradient. But dominance index decrease along the successional gradient. Evenness index was correlated with lower. In the ecological stability analysis of the habitat that evaluated by eco-floristic characters, stage I was the most unstable habitat. And the stability of the habitat has improved according to the successional stage.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.664-671
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• 2017

Non-point source pollution is the emission source that unspecifically releases pollutants to water system from unspecific places such as cities, agricultural lands, mountains, and construction sites and its discharge path is not easily identified. Also, it is difficult to design and manage the reduction facilities for the emission quantity is primarily affected from weather conditions like rainfall. Since 2006, the significance of non-point source pollution reduction has been grown in Republic of Korea and this reinforces needs for the installation of reduction facilities. However, because the standards for the installation details and reduction efficiency are not clarified by law, people are preferring technologies that do not require particular maintenance and high expenses. The purpose of this study is to examine and maintain the efficiency of non-point source pollutants reduction facility which uses expended polypropylene as a media. The higher the depth of the media, the less range of variations in the reduction efficiency was observed and the final efficiency was also increased. When the media depth was 60 cm, the average reduction efficiency was 94% and 90% where linear velocities were 10 m/hr and 20 m/hr respectively. The results from 180 minutes operation in 10 m/hr and 20 m/hr of linear velocities were slightly different in head loss changes which were caused by media depth variations. The backwash experiments which were conducted in triplicate showed the reduction efficiency decreased as the time went on because of the media clogging. However, it was found that after the backwashing the reduction efficiency was increased as effective as the efficiency of the initial filtration.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.2
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• pp.7-16
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• 1986

This study was carried out to investigate the effects of such erosion control measures as sowing, planting and small earth structures on the soil and vegetation. In order to study the changes in soil and vegetation, 36 plots were surveyed from 1981 to 1982 in the large erosion control area which is restored last 20 years. The factors which were measured included vegetation coverage, tree growth, number of species, soil depth, soil consistancy, and Chemical properties of soil. The results were as follows; 1) Maximum coverage of the overstory and understory was attained 7 years after the initiation of erosion control. So the overstory need to be tended and pruned. 2) Diversity of species increased until age 6 after which it began to decrease. 3) In order of tree growth, black locust was the fastest, followed by siberian alder and pitch pine. The initial growth of black locust, though the best among the 3 tree stop., decreased rapidly year by year. At the same time, siberian alder and pitch pine grew well until 12 and 6 years after the initiation of erosion control respectively. 4) Fifty percent of the initially planted trees died within 8 yeard. The mortality of siberian alder occurred until the 20th year while the mortality of pitch pine stopped after 10 years. Thereafter 500 trees per hectare were maintained. 5) The soil depth in A and B horision increased by 2cm annually during 20 years. The soil consistency also decreased rapidly until 7th year. The physical soil properties of the rehabilitated areas were improved after the 14th year. 6) The soil pH tend to decrease from 5.3 during the first year to 5.1 during the twentieth year. 7) The organic matter and nitrogen content in the soil were increased by fertilization but after 20 years these nutrients are still deficient for normal tree growth. 8) The phosphorous content in the soil was high in the first year but the longer the period after the initiation of erosion control the lese the content of phosphorous. 9) The biomass of black locust was the highest and increased continuously. The biomass of siberian alder on the contrary decreased from the 15th year because the number of trees in this place was very low. The total biomass in the twentieth year after erosion control initiation was 105.7 ton per hectare.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.21-36
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• 2019

Dead fuel moisture content is a key variable in fire danger rating as it affects fire ignition and behavior. This study evaluates simple regression models estimating the moisture content of standardized 10-h fuel stick (10-h FMC) at three sites with different characteristics(urban and outside/inside the forest). Equilibrium moisture content (EMC) was used as an independent variable, and in-situ measured 10-h FMC was used as a dependent variable and validation data. 10-h FMC spatial distribution maps were created for dates with the most frequent fire occurrence during 2013-2018. Also, 10-h FMC values of the dates were analyzed to investigate under which 10-h FMC condition forest fire is likely to occur. As the results, fitted equations could explain considerable part of the variance in 10-h FMC (62~78%). Compared to the validation data, the models performed well with R2 ranged from 0.53 to 0.68, root mean squared error (RMSE) ranged from 2.52% to 3.43%, and bias ranged from -0.41% to 1.10%. When the 10-h FMC model fitted for one site was applied to the other sites, $R^2$ was maintained as the same while RMSE and bias increased up to 5.13% and 3.68%, respectively. The major deficiency of the 10-h FMC model was that it poorly caught the difference in the drying process after rainfall between 10-h FMC and EMC. From the analysis of 10-h FMC during the dates fire occurred, more than 70% of the fires occurred under a 10-h FMC condition of less than 10.5%. Overall, the present study suggested a simple model estimating 10-h FMC with acceptable performance. Applying the 10-h FMC model to the automatic mountain weather observation system was successfully tested to produce a national-scale 10-h FMC spatial distribution map. This data will be fundamental information for forest fire research, and will support the policy maker.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.61-71
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• 2022

Data from an investigation of vulnerable conifer species in the subalpine zone in Korea obtained by the Korea Forest Service in 2017-2018 and monitoring research conducted by the National Institute of Forest Science since 2014 were used to analyze the status of distribution and growing condition of three major conifer species (Abies nephrolepis, Abies koreana, and Picea jezoensis) in the subalpine zone in the Baekdudaegan protected area. The distribution area of the studied species in the Baekdudaegan protected area was ca. 74% (8,035 ha) of the total distribution area in Korea, indicating that Baekdudaegan is a core area for conservation and restoration of subalpine conifer species. From decline index [A. nephrolepis in Mt. Taebaeksan and Mt. Deogyusan increased by 77.3% and 29.6%, respectively; A. koreana in Mt. Jirisan (Chunwangbong Peak) increased by 45.2% in four years; and P. jezoensis in Mt. Jirisan (Chunwangbong Peak) increased by 47.8% in two years] and seedling frequency (lower frequency of newly recruited seedlings than dead seedlings) results, the studied species are expected to face difficulties in sustainability. In contrast, at Mt. Seseoksan and Chunwangbong Peak in Mt. Jirisan, the health of trees and seedling frequency showed a partial tendency to recover and increase. In addition, we identified the relationship between the decline index and seedling frequency. These results will support the implementation of conservation strategies for vulnerable conifer species in the subalpine zone.