• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.329-333
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• 2006

Most of volcanic ash soils in South Korea are distributed in Jeju province which is an island placed on southern part of Korea and has steep slope mountain area. There are many soils containing high contents of organic matter (OM) derived from volcanic ash in Jejudo, also. Therefore, irrigation and drainage in volcanic ash soil different with general soil which has low OM content have to be applied with another management way, but studies searching appropriate methods for them are set on insufficient situation because the area of volcanic ash soil in South Korea is only 1.3% (130,000ha). This study was conducted for analysis of soil water content and irrigation quantity appropriate for crops cultivated in volcanic ash soil with high OM content. Although soils with different soil color have the same soil texture, soil water characteristics curve by soil color showed the difference of water retention capability by OM content. But, this characteristics classified with soil color could be unified by scaling technique with similitude analysis method which get dimensionless water content using a present water content, a residual water content and saturated water content (or water content at 10kPa). A relation of gravimetric soil water content (GSWC) and dimensionless water content by the results showed a form of power function. The dimensionless water content (DWC) express a relative saturation degree of present water content. This was also expressed by van Genuchten model which describe the relation between relative saturation degrees and matric potentials. These results on soil water characteristics curve (SWCC) of volcanic ash soil will be the basic of irrigation plan in area having high organic contents into soil.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.777-786
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• 2011

In the previous researches for storm sewer design, the flow path, pipe diameter and pipe slope were determined to minimize the construction cost. But in the sewer networks, the flows can be changed according to flow path. The current optimal sewer layout models have been focussed on satisfying the design inflow for sewer designs, whereas the models did not consider the occurrences of urban inundation from excessive rainfall events. However, in this research, the sewer networks are determined considering the superposition effect to reduce the inundation risk by controlling and distributing the inflows in sewer pipes. Then, urban inundation can be reduced for excessive rainfall events. An Optimal Sewer Layout Model (OSLM) was developed to control and distribute the inflows in sewer networks and reduce urban inundation. The OSLM uses GA (Genetic Algorithm) to solve the optimal problem for sewer network design and SWMM (Storm Water Management Model) to hydraulic analysis. This model was applied to Hagye basin with 44 ha. As the applied results, in the optimal sewer network, the peak outflow at outlet was reduced to 7.1% for the design rainfall event with 30 minutes rainfall duration versus that of current sewer network, and the inundation occurrence was reduced to 24.2% for the rainfall event with 20 years frequency and 1 hour duration.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.7-13
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• 1985

The cropping management factor, C, in the Universal Soil Loss Equation (USLE) has been measured on a newly reclaimed Yesan sandy loam of 20% slope under various cropping system. Soil losses measured from lysimeter were 12.9, 5.4, 3.1, and 1.2 ton/10a for clean tilled, corn, barley-soybean, and grass, respectively. The values of C to be utilized in Soil-Loss Equation was obtained as fallows; corn 0.47, upland rice 0.34, barley-soybean 0.18, barley-sweet potato 0.10, grass 0.08, barley-corn 0.34, wheat-soybean 0.25, barley-corn (Soybean) 0.42, barley-corn (sweet potato) 0.37, wheat-sesame 0.20, barley-red pepper 0.18, red pepper 0.32, sesame 0.28, potato-soybean 0.26, respectively. According to the comparisons between the actual soil loss measured by lysimeter and the soil loss predicted by the USLE, the smallest difference of both method came from barley-soybean while the largest came from corn.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.517-524
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• 1995

This study was conducted to investigate the characteristics of the road alignment, correlations among evaluation factors of the alingment, and the relationships between the evaluation factors and terrain factors for the forest road of five National Forest Offices. The results were as follows : 1. The elongation coefficients(${\eta}$) of forest road in Kangnung and Wonju National Forest Office were ranged 0.3~0.5, and those of Andong, Namwon, and Kongju National Forest Offices were ranged 0.2~0.3 in straight line of 100m, 200m, and 300m. 2. Three different types of plane alignment were identified for Kangnung and Wonju National Forest Offices, Namwon and Kongju National Forest Offices, Andong National Forest Office. However, longitudinal alignment for five National Forest Offices tended to be similar conditions. 3. Low correlation coefficients were calculated in the relation between elongation coefficients(${\eta}$) and evaluation factors of plane alignment(curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$)) for three straight lines. On the contrary, high correlation coefficients were obtained among the relations of curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$). 4. Slope(%) were closely correlated with plane alignment, and so were the relationships between frequency of valleys and streams(No./km) and elongation coefficients(${\eta}$) of forest road.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.201-210
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• 2005

This study was conducted to prepare efficient and systematic measures for nature conservation and management in Beomseom Islet, and to provide for basic data to investigate the process of vegetation change in the future. The vegetation of Beomseom Islet was classified to six vegetation type; i.e., Miscanthus sinensis community, Pinus thunbergii community, Iythophyte vegetation, evergreen broad leaf community, shrub community, and Pseudosasa japonica community. The size of each vegetation type was 40,230 $m^2$ ($23.3\%$) for shrub community, 39,366 $m^2$($22.8\%$) for Iythophyte vegetation, 30,012 $m^2$ ($17.4\%$) fur Pinus thunbergii community, 29,853 $m^2$ ($17.3\%$) for Miscanthus sinensis community, 5,564 $m^2$ ($3.2\%$) for evergreen broad leaf community, and 3,325 $m^2$ ($1.9\%$) for Pseudosasa japonica community. The area of non-vegetated sea cliff Bone that composed of bare rocks is 24,246 $m^2$($14.1\%$). We estimated that these distribution patterns of vegetation were the result of various environmental factors such as the steepness of slope and shallowness of soil as well as the cultivation of exotic plants causing disruption of native vegetation.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.375-382
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• 2017

In this study, general characteristics of dynamic behavior of stormwater runoff from a small impervious catchment was investigated from a series of simulations for a radial type surface runoff. Based on the simulation results, a better placement strategy for stormwater inlets to improve performance of a structural best management practice (BMP) was suggested. The degree of pollutant first flush from an ideal radial type impervious catchment was simulated using a 1-D diffusion wave equation coupled with a pollutant transport equation. The results showed that the first flush of the chemical oxygen demand was the strongest when the catchment length ranged 30-50m at a bed slope of 0.02. This result suggested that a required degree of the first flush can be intentionally obtained by just changing the locations and numbers of stormwater inlets, and thereby adjusting the catchment length. Particularly, the overall performance of a structural BMP in reducing pollutant load can be improved by placing the stormwater inlets at locations for obtaining a required first flush strength.

• Spatial Information Research
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• v.8 no.1
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• pp.85-99
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• 2000

Accurate information on habitat distribution of protected fauna is essential for the habitat management of Korea, a country with very high development pressure. The objectives of this study were to develop a habitat suitability model of wild boar based on GIS and logistic regression, and to create habitat distribution map, and to prepare the basis for habitat management of our country s endangered and protected species. The modeling process of this restudyarch had following three steps. First, GIS database of environmental factors related to use and availability of wild boar habitat were built. Wild boar locations were collected by Radio-Telemetry and GPS. Second, environmental factors affecting the habitat use and availability of wild boars were identified through chi-square test. Third, habitat suitability model based on logistic regression were developed, and the validity of the model was tested. Finally , habitat assessment map was created by utilizing a rule-based approach. The results of the study were as folos. First , distinct difference in wild boar habitat use by season and habitat types were found, however, no difference in wild boar habiat use by season and habitat types were found , however, ho difference by sex and activity types were found. Second, it was found, through habitat availability analysis, that elevation , aspect , forest type, and forest age were significant natural environmental factors affecting wild boar hatibate selection, but the effects of slope, ridge/valley, water, and solar radiation could not be identified, Finally, the habitat at cutoff value of 0.5. The model validation showed that inside validation site had the classification accuracy of 73.07% for total habitat and 80.00% for cover habitat , and outside validation site had the classification accuracy of 75.00% for total habitat.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.22-34
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• 2004

An artificial disturbance like fragmentation in watershed forest has impacted a sustainability of watershed ecosystem, therefore this research quantified the landscape structure in the Geumho river watershed using landscape indices and GIS. Landscape indices were calculated from the forest distributed maps for 24 subwatersheds. Three common factors, which explained about 85% of the variation in the original data, were extracted by a factor analysis. The fragmentation gradient in forest landscape, which was calculated from the factor scores, was correlated with proportion of urban land (r=0.827, p<0.01, $R^2$=0.685), elevation (r=-0.637, p<0.01) and slope gradient (r=-0.593, p<0.01). The result of the study presented that the methodology and the values of landscape indices to assess the structural patterns of forest landscape for the Geumho river watershed management. Future research will be directed towards the detection of impacts of landscape patterns and their changes on the integrity of watershed environments.

• The Journal of the Acoustical Society of Korea
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• v.24 no.6
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• pp.353-357
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• 2005

Declining auditory performance with advanced age is a well known and common problem that is becoming more Prevalent due to the increasing number of elderly people in our society. We introduce a novel ARCISM (Audiogram Result Computer Input. Save & Management software) data management program which enables the assessment of the risk of past history of hearing impairment on the basis of known risk factors. This study investigates the reference levels of pure tone hearing threshold of normal aging in Korean and the difference between fenders. The subjects were carefully selected by questionnaire and absence of any history of otologic infection, noise exposure. and ototoxic drug among 1603 subjects. who visited Health Promotion Center in Daegu Fatima Hospital for one year. The results show (1) hearing sensitivity declines with age. (2) higher frequency shows steeper slope of hearing declines than lower frequency. and (3) there were more hearing loss at 4 and 8 kHz in men than in women. Due to the ARCISM program. it was possible to manage huge data of hearing results and to obtain the reference level of a9e-related hearing declines. Furthermore, we expect that the results of this study can be the fundamental data for hearing rehabilitation for the elderly and for developing suitable hearing aids for Korean.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.710-717
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• 2015

This study was conducted investigate population size and habitat use for the conservation and management of the endangered long-tailed goral in the Seoraksan National Park using feces and camera trap during 2010 to 2014 (track survey, camera trap). As a result of feces tracking and camera trap, its population size was estimated as 160 (camera trap)~251 (feces) individuals in the Seoraksan National Park. The goral prefer $35^{\circ}{\sim}60^{\circ}$ (slope), 600~700m (elevation), NE (aspect), 0~50m (distance to stream), 300~600m (distance to road) and bread-leaved forest (forest type) according to field tracking of fecal. Based on field camera trap, we estimated the age classes of goral populations and activity of gorals during day-time (07-18 time, 56.5%) and night-time (18-07 time, 43.5%). Such analyses of population size and habitat use of the goral could be applied as important fundamental data for conservation of gorals and management of their habitats.