• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.463-466
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• 2013

We examined relationship between rainfall and triggering of shallow landslides in South Korea, based on hourly rainfall data for 478 shallow landslides during 1963-2012. Rainfall intensity(I) and duration(D) relationship was analyzed to obtain the I-D threshold for the initiation of a shallow landslide using the quantile regression analysis. The I-D threshold equation from in this study is: $I=9.64D^{-0.27}$($4{\leq}D{\leq}76$), where I and D are expressed in millimeters per hour and hours, respectively. In addition, rainfall criteria were proposed to predict the potential to cause landslides, based on values of I-D and cumulative rainfall derived from quantile regression analysis. Our findings may provide essential data and important evidences for the improvement of landslide warning and evacuation system.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.2 s.109
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• pp.71-82
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• 2005

A large scale of riverside rearrangement has been recently done in the major rivers in Korea. So inundation possibility in agricultural area closed by these rivers has been higher than the possibility a few years ago. However, land use in this area has not been adjusted to a change of this situation near the rivers. Therefore, when typhoon or heavy rain is happened on this area, it can cause a large damage in agricultural area. This study analyzed inundation potentiality in agricultural area at Ibang-myeon, Changnyeong-gun, Kyeongnam-province, Korea by using the logistic regression model and the piecewise regression model. The first thing we did was to transfer the inundation area per elevation to the accumulated inundation area per elevation. This accumulated inundation area per elevation as an distribution function could be described by the logistic regression model(LRM), and piecewise regression model(PRM) could make it much more accurate to analyze the inundation area per elevation. As a result, the regression models derived from LRM and PRM showed $R^2$ over 0.950. The models derived from LRM and PRM in Ibang-myeon noted that frequently inundated area(FIA) was shown up to 12.12m in elevation, and potentially inundated area(PIA) was shown up to 14.60m in elevation. In FIA, regular agricultural activity would be impossible. And It would be not easy to continue the regular agricultural activity in PIA. So, this land should be rearranged to be used for a buffer zone for ecosystem protection, landscape conservation and things like that in riverside.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.180-183
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• 2011

Recently, environmental problems have been deteriorating rapidly. Therefore, there is an urgent need to establish policies and research in the conservation of the global environment. Many researchers are studied in environment systems to prevent and reduce pollution of water, air and soil actively. In this paper, several parameters such as temperature, humidity, illumination, barometric pressure, dew point, water quality data, and air conditions are collected and transmitted thorough wireless sensor network. The field server is located in the coastal and marine area so that any abrupt changes can be detected quickly. In addition, WSN based flooding routing protocol for efficient data transmission is designed to support and monitor information of climate and marin factors.

• Korean Journal of Organic Agriculture
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• v.1
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• pp.19-28
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• 1992

The definitions of organic farming method has rather philosophical meaning than application of agricultural practices. The meaning of organic farming method has certainly basic differences in comparison with the conventional farming methods. The main definitions of organec farming method have certainly to reduce or not to apply any kinds of farm inputs materials by increasing quality of agricultural prod-ucts. However, the quality of produced food by organic farming method should be improved in compari-son with cinvethional farming method. By applying organic method, the qualith of food, envir-onment as well as spiritual attitude of human being should be improved in future. Actually, there are very wide fields of research on organic farming methods such as production tech-niques, soil and water conservation, plant and animal production, marketing and consumers behavior on organic products. In this article the present situation of organic farming methods in the United States of Americal is investigated in cimparison with conventional rice production. The production cost of rice per acre in the United States of America mde 58, 788 Won in 1986, while it was 121, 699 Won in Korea having about 107 percent higher in Korea than tham the U.S.A There is a larger rice farm cost analysis between conventional and organic rice farm in California. The cash cost pre 1 lbs of conventional rice made 4.86 $, while the organic rice was 6.96$ showing about 43.2%higher level of cost in organic products(1 lbs=0.45359kg) At present, there is less econmic advantage of organic rice production in California because of lower yields as well as price levels, Therefore, the total net return over cash cost peracer/yeat was a little lower in organic rice production than conventional rice prouction.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1162-1174
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• 2010

Excavated gold brocade, often shows signs of serious damage and contamination from environmental factors such as exposure to soil or human remains. Therefore, most of the conservation procedures are focused on the consolidation of the gold thread and on cleaning with water or organic solvents. Indiscreet cleaning using solvents could damage the gold leaf, which identifies the features of fabric. There is a need to develop cleaning protocols appropriate for relics through the careful analysis of the condition of the relics. This study finds the appropriate cleaning method for the excavated gold brocade. Four different cleaning methods, vacuum cleaning, kneaded rubber eraser cleaning, immersion wet cleaning, and absorption wet cleaning were applied to the excavated gold brocade. The degree of cleaning and damage were examined depending on the cleaning methods, changes to the physical condition (before and after cleaning) were also analyzed through the surface observation. Although immersion cleaning showed the best cleaning result, this method had a risk of damage to the gold thread. Absorption wet cleaning safely eliminated the various soluble contaminants and the rotten smell of relics. Kneaded rubber eraser was suitable for the excavated gold brocade fabric because it can be applied to selective parts, intentionally excluding some sensitive parts such as the gold thread. The vacuum cleaning method required special attention because of a possibility of suctioning off loosely attached gold leaf. Dual cleaning, the kneaded rubber eraser cleaning, followed by the absorption cleaning was the most effective method to preserve and clean excavated gold brocade.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.178-186
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• 2018

Generally, in terms of the development of irrigation scheme, the efficient water resource management that supplies the irrigation water in consideration of the required time and accurate quantity to grow the crop should be conducted. The water resource assessment should precede to supply the irrigation water efficiently. The water resources assessment is divided into the water requirement analysis and the water availability assessment. In case of Korea, the major crop is paddy rice unlike crops of Africa, such as sugarcane, maize, and cassava, etc. Because it is not familiar with the method for upland irrigation development in tropical area, it needs to know the water resources assessment for irrigation scheme development about these crops. The Natama Scheme in Chiradzulu District of the Southern Malawi was selected as study area, which has tropical climate. From the collected meteorological data, the evapotranspiration was analyzed by Penman-Monteith Method and the effective rainfall was analyzed by USDA Soil Conservation Service Method. This study displays the results that for study area, the evapotranspiration varies from 2.80 mm/day to 5.51 mm/day and the effective rainfall varied from 2.1mm to 149.0mm. According to the selected crop (Green Maize, Dry Maize), the unit water requirement (UWR) and water demand (WD) considering the irrigation efficiency, irrigation time and irrigation area were estimated to be $0.00122m^3/s/ha$ and $0.0122m^3/s$ respectively. For the water availability assessment, the runoff of Natama scheme was calculated by specific yield method. The water availability was evaluated through reviewed differences of discharge between $Q80_{intake}$ and Total WD, and the irrigation water can be supplied sufficiently in the existing 10ha of Natama scheme. As a result of reviewing the extensibility of irrigable area, total WD of scheme is $0.02313m^3/s$, and $Q80_{intake}$ is $0.02387m^3/s$ ($Q80_{intake}$ > Total WD). Therefore, Natama scheme can be extended from 10 ha to 17 ha in the dry season in consideration of the $Q80_{intake}$.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.115-120
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• 2004

Coarse woody debris (CWD, $\ge$ 5 cm in maximum diameter) is an important functional component, especially to nutrient cycling in forest ecosystems. To compare mass and nutrient dynamics of CWD in natural oak forests, a two-year study was conducted at Quercus serrata and Q. variabilis stands in Yangpyeong, Kyonggi Province. Total CWD (snag, stump, log and large branch) and annual decomposition mass (Mg/ha) were 1.9 and 0.4 for the Q. serrata stand and 7.5 and 0.5 for the Q. variabilis stand, respectively. Snags covered 72% of total CWD mass for the Q. variabilis stand and 42% for the Q. serrata stand. Most of CWD was classified into decay class 1 for both stands. CWD N and P concentrations for the Q. variabilis stand significantly increased along decay class and sampling time, except for P concentration in 2002. There were no differences in CWD N concentration for the Q. serrata stand along decay class and sampling time. However, CWD P concentration decreased along sampling time. CWD N and P contents (kg/ha) ranged from 3.5∼4.7 and 0.8∼1.3 for the Q. serrata stand to 22.8∼23.6 and 3.7∼4.7 for the Q. variabilis stand. Nitrogen and P inputs (kg/ha/yr) into mineral soil through the CWD decomposition were 0.7 and 0.3 for the Q. serrata stand and 1.6 and 0.3 for the Q. variabilis stand, respectively. The number of CWD and decay rate were main factors influencing the difference in CWD mass and nutrient dynamics between both stands.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.703-709
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• 2012

We studied the community fluctuations of benthic macroinvertebrates of forest fired area in Samcheok-si from 2001 to 2009. Total collected macroinvertebrates species were 18 belonging to 14 families, 8 orders, 3 classes, and 2 phyla in 2001, and 70 belonging to 40 families, 15 orders, 7 classes and 5 phyla in 2009 (9 years after the forest fire). During the first four years after the forest fire, dipteran insects were dominant, but after then, ephemeropteran insects have increased in abundance and richness. As time elapsed from the fire, dominance indices were decreasing, while species diversity, richness and species evenness indices were increasing.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.156-162
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• 2009

Nebkhas are widely distributed in farming-pastoral zones, typical grassland and desert margins. In the southeast of the Inner Mongolia Plateau, it is mainly distributed at the leeward of cultivated land and alluvial fan, severe deterioration rangeland and around residential points. Through the field measurement and statistical analysis of Caragana microphylla Lam. Nebkhas morphological parameters (length, width and height of Nebkhas are included), the results show that there were close correlations between the Nebkhas morphological parameters. The ranges of height and width of Nebkhas changed dramatically and have reached up to 11.44 m and 7.97 m respectively, however, the change range of height was relatively smaller and just 1.09 m. The morphological parameters change of the same type Nebkhas in the same region was large ranging from 0.56 m in height, 3.56 m in width to 6.96 m in length, while the morphological characteristics of the same type Nebkhas in different regions were much similar. A correlation between length and width was significantly positive, but the correlations between height and length, and between height and width were much more complicated. It can be concluded that the Nebkhas in Zhengxiangbai Banner and Taipusi Banner were at the initially growing stage, while the Nebkhas in Huade County belonged to a transitional stage from the growing phase to the stabilizing phase. The changing regularity of distance between Nebkhas in along-wind direction was not consistent.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.71-79
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• 2007

Land suitability assessment has been enforced by the National Land Planning and Utilization Act since 2003 to prevent urban sprawl and protect natural environment. It assesses developmental, agricultural or preservable suitability of land parcel according to such criteria as soil, location and usability by local governments. Land suitability assessment system (LSAS) has been introduced to prevent cursory development by urban sprawl and to lead a harmonious development with conservation in the non-urban area. However, with the lack of experience and knowledge various problems have been arisen in the operation of this system, raising a question for the improvement of the assessment unit of land. The purpose of this study is to investigate methods of developing land assessment as a sustainable land use management tool. In this study, land suitability assessment has been executed through geographic information systems. On the basis oh the results of analysis, practical and institutional problems are described, and technical and institutional solutions are suggested.