• Journal of the Korean GEO-environmental Society
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• v.17 no.5
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• pp.37-46
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• 2016

In order to determine the variability of environmental characteristics of lightweight air-foamed soil using marine clay according to freezing-thawing and soaking conditions, unconfined compressive strength of the lightweight air-foamed soil samples made by changing the amount of cement under curing conditions of outdoor low temperature, underground or indoor wetting were observed. Compressive strength was not increased under freezing-thawing (temperature range of $-9.1^{\circ}C{\sim}17.2^{\circ}C$) regardless of the amount of cement but the more cement using, it was increased rapidly by underground curing conditions within 30 cm beneath ground level. Therefore, it is necessary to install insulation layer cutting off exterior cold air after construction of lightweight air-foamed soil in condition of freezing-thawing. Bulk density was increased too small under the long-time soaking condition, it tended to decrease rapidly when samples were dried up and had below 6% of water contents. But variability of compressive strength and bulk density was very small for preventing drying and keeping its wet state. The lightweight air-foamed soil that installed beneath ground water level or covered by soil can be evaluated as a long-term reliable construction material.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.82-82
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• 2019

황해쑥(Artemisia argyi Lev. et. Vnt)은 국화과의 다년생 초본 식물로서 쑥, 산쑥과 함께 건조한 것이 애엽이라는 생약재로 쓰이며 2016년 기준 전국적으로 81 ha에서 871톤이 생산되고 있다. 주요 유효성분으로 Eupatilin, Jaceosidin 등이 있으며 위궤양에 효과가 있다고 알려져 있어 최근에는 스티렌정 등 신약원료로 각광 받고 있다. 황해쑥은 종자번식 뿐만 아니라 포복경을 이용한 영양번식이 가능하며 현재까지 '섬애' 등 1품종이 개발되어 있으나 농가와 산업체가 요구하고 있는 수량성 또는 Eupatilin 등 성분함량이 높은 품종개발이 필요하다. 국내 연구 결과를 보면 대부분 년 1회 수확을 기준으로 연구되어 왔으나 실제로는 년 2회 수확하는 경우가 더 많다. 따라서 본 실험에서는 년 1회 뿐만 아니라 년 2회로도 수확하여 조사하였다. 시험재료는 AA1801 등 7계통 이며, 시비량은 10 a 당 질소 15.3 kg 인산 20 kg 가리 5 kg이고, 흑색 비닐을 피복한 후 조간 30 cm 주간 15 cm로 하였다. 시험구배치는 난괴법 3반복으로 하였으며 포복경을 5 cm로 잘라 4월 19일에 정식하였다. 1회 수확 시에는 8월 12일, 2회 수확 시에는 6월 17일, 9월 19일에 수확 하였다. 년 1회 수확 시 계통 별 생육특성을 보면, 초장은 202.4~231.5 cm로 평균 213.6 cm 였으며 경경은 10~12.14 mm로 평균 10.9 mm 였다. 분지수는 32.6~37.3개로 평균 35.2개 였으며 엽병장, 엽장, 엽폭은 2.4~4.2 cm, 9.3~12 cm 9.2~12.2 cm로 평균 3.3 cm, 10.7 cm 그리고 10.9 cm 였다. 전초의 생중량과 건중량은 각각 4.9~6.9 kg, 1.8~2.7 kg로 평균 5.5 kg, 2.1 kg 이였다. 특히 AA1902는 다른 계통에 비해 분지수는 적었으나 초장이 크고 경경이 굵었으며 생중량과 건중량도 가장 무거웠다. 년 2회 수확 시 전초의 생중량과 건중량은 각각 5.1~6.2 kg, 1.7~2.0 kg로 평균 5.6 kg, 1.8 kg 이였다. 수량성으로 봤을때는 AA1902는 1회 수확에 적합하며 AA1801, AA1802는 2회 수확 시 생중량과 건중량이 무거웠다. 또한 AA1903의 경우 수확 회수와 상관없이 수량성이 높은 계통으로 판단되었다. 본 자료는 황해쑥 품종육성의 기초자료로 활용하고자 한다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.1-6
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• 1985

This experiment was designed to determine the effect of light quality on the appearance of photobleaching leaves during the cure of Burley Tobacco. The harvested and browned tobacco leaves were exposed to sunlight in pipe houses covered with 8 kinds of color vinyls (white, red, black, yellow, purple, orange, blue, green), and exposed to ultraviolet rays(20W x 3) and infrared rays (150W x 2) in curing chamber (1.2 x 1.2 x 1.2m). Photobleaching occured more at lower position leaf and after the leaves being browned when the curing was done in sunlight under a transparent vinyl. But photobleaching leaves were 5-6% of total cured leaves in sunlight under all kinds of color vinyl houses. It seems that photobleaching mainly induced by ultrabiolet rays of sunlight, and humidity too influenced. Yellow, orange and purple vinyl were durable and effective as shading material of color vinyls. since white and red vinyl tore easily in two monthes in strong sunlight and under black and blue vinyl houses curing period was longer than others.

• Journal of the Korean Geotechnical Society
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• v.23 no.7
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• pp.77-86
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• 2007

Installation damage of 3 types of geogrids was evaluated with compaction condition by laboratory tester. This experimental was in accordance with ENV ISO 10722-1. First, soil distribution and water content were conducted. And then we changed cyclic loading time and type of geogrids as a factor of installation damage. The samples are woven, warp-knitted, welded type of 6, 8, 10T. This study aims to give an insight into the relationships between installation damage and cyclic loading time. The result of studies was that strength of the damaged geogrids can be closely correlated with the time of loading cycles. Especially, welded type shows slower slope than two types of geogrids due to coating materials. That means welded type is coated with PP (Polypropylene), but the other two types of geogrids are coated with PVC (Polyvinyl Chloride). To confirm another factor different method was performed. The size of soil was used between 9.5 mm and 23.5 m to compare initial experimental. Cyclic loading compaction is taken 200 times before installation test and the reason is that the reduction factor of this case by installation damage was higher than other compaction loading conditions.

• Journal of the Korean earth science society
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• v.38 no.4
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• pp.269-282
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• 2017

In this study, the surface broadband emissivity ($3.0-14.0{\mu}m$) was calculated using the multiple linear regression model with narrow bands (channels 29, 30, and 31) emissivity data of the Moderate Resolution Imaging Spectroradiometer (MODIS) on Earth Observing System Terra satellite. The 307 types of spectral emissivity data (123 soil types, 32 vegetation types, 19 types of water bodies, 43 manmade materials, and 90 rock) with MODIS University of California Santa Barbara emissivity library and Advanced Spaceborne Thermal Emission & Reflection Radiometer spectral library were used as the spectral emissivity data for the derivation and verification of the multiple linear regression model. The derived determination coefficient ($R^2$) of multiple linear regression model had a high value of 0.95 (p<0.001) and the root mean square error between these model calculated and theoretical broadband emissivities was 0.0070. The surface broadband emissivity from our multiple linear regression model was comparable with that by Wang et al. (2005). The root mean square error between surface broadband emissivities calculated by models in this study and by Wang et al. (2005) during January was 0.0054 in Asia, Africa, and Oceania regions. The minimum and maximum differences of surface broadband emissivities between two model results were 0.0027 and 0.0067 respectively. The similar statistical results were also derived for August. The surface broadband emissivities by our multiple linear regression model could thus be acceptable. However, the various regression models according to different land covers need be applied for the more accurate calculation of the surface broadband emissivities.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.74-85
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• 2020

Darangnon in Gachon Village, Namhae-gun, Gyeongsangnam-do, is the first designated environment among Korea's industrial-based historical and cultural sites and is still the only one that involves agricultural activities. Although the stonework, which is the infrastructure environment here, has limitations that inevitably lead to natural and artificial deformation due to its nature, there has been no research to consider the situation so far. As of the end of May 2020, this study investigated and analyzed the damage in the sub-area of the survey, which is approximately 30% of the scope of the designation of the scenic spot, from a quantitative and qualitative perspective. As a result of the study, the state of loss, which reveals the physical damage of the arctic rice paddy stone retaining wall in the environment under investigation, was particularly serious around the coast, in the northern area with high slopes, and near tourist information centers and parking lots. On the other hand, the qualitative aspect of the damage to the stonework was noticeable in the repair of heterogeneous materials on the stone retaining wall adjacent to the village and parking lot, and the landscape damage caused by the cladding of plants was found in an environment far away from the residence. In addition, natural environmental factors such as slopes, elevations, and soil showed a close relationship with the degree of physical damage of the stone retaining wall, the higher the slope, the higher the elevation, and the better the soil drainage, the greater the impact. These results suggest that humanities environmental factors such as cultivation activities and management entities have important factors in the physical damage and management of stone retaining wall. Therefore, it is deemed essential to find management measures with local residents along with improving the agricultural environment, such as securing agricultural water and soil improvement, for the preservation of tuna paddies and stone retaining wall in the future.