• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.59-71
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• 2019

In Mountainous Districts Management Act of Korea Forest Service, slope and elevation criteria are operated to regulate the indiscriminate use of risky land parcels when forestland is converted to other land use types. However, there is a limitation in considering topographical variation with only such two indices in the land parcel. Therefore, in order to supplement insufficient criteria, the slope type standard was developed using Catena, and the ecological condition improved terrain standards. Firstly, the ratio of 'risky slope' in a target forestland parcel was defined to decrease the risk of disasters such as landslides. Secondly, the standard of the ecological location condition was proposed as ecological score by integrating age, diameter and soil depth classes in the target forestland parcels. Thereby, we could prepare reasonable standards that can reduce forestland disasters and ecological damages, as suggesting new topographical and ecological assessment methods for forestland use conversion.

• Ecology and Resilient Infrastructure
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• v.5 no.4
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• pp.257-263
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• 2018

This study is to develop a GSTM (Green infrastructure Surface Temperature Measurment) equipment for reducing the surface temperature of GI by using LID Method. The tests were conducted including GI products such as Greening block, Pervious Block, Soil Block and so on. The GSTM equipment developed by considering the literature surveys are characterized as follows. The non-contact infrared temperature sensor was used to measure the surface temperature, and it was improved to measure the overall average temperature including the center and the corner temperature of the specimen. The developed GSTM equipment was used to compare performance of asphalt and GI products. As a result, the Greening Block show a high difference of $18.4^{\circ}C$ and it contributes to the decrease of surface temperature.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.50-60
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• 2022

In this study, habitat suitability was analyzed for three major honey tree species, namely Kalopanax septemlobus, Tilia amurensis, and Styrax obassis, in the Baekdudaegan Mountains using MaxEnt models. The AUC values indicating the prediction accuracies of the models were 0.747, 0.790, and 0.755 for K. septemlobus, T. amurensis, and S. obassis, respectively. The most important variables for K. septemlobus and T. amurensis were elevation, mean annual temperature, and slope, whereas mean annual temperature, elevation, and mean annual precipitation were the most important predictors for S. obassis. For all three studied species, elevation and mean annual temperature were the most important topographic and climatic factors, respectively, indicating that such variables are crucial for explaining species distribution. Honey tree species are essential resources in forest beekeeping, a high value-added process for improving forest income, and this study identified sites with the potential for management of such species in the Baekdudaegan Mountains, where it may be possible to establish a honey forest. However, the accuracy of the models should be improved through comprehensive analysis with abiotic variables, such as soil properties and aridity, which affect the distribution of honey tree species, as well as biotic variables, such as interspecific competition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.697-707
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• 2008

The grid-based KIneMatic wave STOrm Runoff Model (KIMSTORM) by Kim (1998) predicts the temporal variation and spatial distribution of overland flow, subsurface flow and stream flow in a watershed. The model programmed with C++ language on Unix operating system adopts single flowpath algorithm for water balance simulation of flow at each grid element. In this study, we attempted to improve the model by converting the code into FORTRAN 90 on MS Windows operating system and named as ModKIMSTORM. The improved functions are the addition of GAML (Green-Ampt & Mein-Larson) infiltration model, control of paddy runoff rate by flow depth and Manning's roughness coefficient, addition of baseflow layer, treatment of both spatial and point rainfall data, development of the pre- and post-processor, and development of automatic model evaluation function using five evaluation criteria (Pearson's coefficient of determination, Nash and Sutcliffe model efficiency, the deviation of runoff volume, relative error of the peak runoff rate, and absolute error of the time to peak runoff). The modified model adopts Shell Sort algorithm to enhance the computational performance. Input data formats are accepted as raster and MS Excel, and model outputs viz. soil moisture, discharge, flow depth and velocity are generated as BSQ, ASCII grid, binary grid and raster formats.

• Journal of Korea Water Resources Association
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• v.52 no.5
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• pp.349-360
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• 2019

The purpose of this study is to evaluate the stream flow and water quality (SS, T-N, and T-P) behavior of Nakdong river basin ($23,609.3km^2$) by simulating the dam and weir operation scenarios using SWAT (Soil and Water Assessment Tool). The operation senarios are the simultaneous release for all dam and weirs (scenario 1), simultaneous release for all weirs (scenario 2), and sequential release for the weirs with one month interval from upstream weirs (scenario 3). Before evaluation, the SWAT was calibrated and validated using 11 years (2005-2015) daily multi-purpose dam inflow at 5 locations (ADD, IHD, HCD, MKD, and MYD), multi-function weir inflow at 7 locations (SHW, GMW, CGW, GJW, DSW, HCW, and HAW), and monthly water quality monitoring data at 6 locations (AD-4, SJ-2, EG, HC, MK-4, and MG). For the two dam inflow and dam storage, the Nash-Sutcliffe efficiency (NSE) was 0.56~0.79, and the coefficient of determination ($R^2$) was 0.68~0.90. For water quality, the $R^2$ of SS, T-N, and T-P was 0.64~0.79, 0.51~0.74, and 0.53~0.72 respectively. For the three scenarios of dam and weir release combination suggested by the ministry of environment, the scenario 1 and 3 operations were improved the stream water quality (for T-N and T-P) within the 3 months since the time of release, but it showed the negative effect for 3 months after compared to scenario 2.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1467-1475
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• 2015

The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA₁, GA₃, GA₇, GA₈, GA₉, GA₁₂, GA₁₉, GA₂₀, GA₂₄, and GA₅₃), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.416-422
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• 2020

In this study, eco-friendly biodegradable materials were prepared using poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and hydrogenated castor oil power (HCO) as an additive. The prepared PLA/PBAT/HCO blended films were characterized by the scanning electron microscope (SEM) and fourier-transform infrared spectroscopy (FT-IR). The results of SEM analysis indicated that PLA/PBAT (8 : 2) blended films added HCO showed no rough area, crack, or large agglomeration when compared with those adding various additives (12-hydroxy stearic acid (12HSA) and cellulose). The FT-IR results indicated the presence of specific peak of HCO in the PLA/PBAT blended films, and its peak intensity increased with increasing HCO content (0~5.0 wt%). Tensile strength, elongation at break, and water barrier and thermal properties of the prepared PLA/PBAT/HCO blended films were also investigated, indicating that the physical and thermal properties was improved more than three times by the addition of HCO. The biodegradability test in soil revealed that the prepared biodegradable materials were degraded by about 6.0~20% after 90 days.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.631-642
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• 2012

This study was carried out to determine the effect of SCB compost leachate on the growth and yield of rice. Field experiment was conducted on sandy loam soil under the different fertilizer management; 80%, 100%, 130% N level of SCB leachate based on 13kg N/10a of conventional farmer application level and chemical fertilizer as control. The plant height and tiller's number of 80 and 100% N levels of SCB leachate were lower than that of the chemical fertilizer plot. But in the plot of 130% N level of SCB leachate the plant height and tillers was higher than that of chemical fertilizer. And the SPAD reading value of leaf in plot of 130% N level was higher than that of the chemical fertilizer. Rice yield in the 80% and 100% SCB leachate was increased from 12 to 13% that of plot of chemical fertilizer. But rice yield of 130% N-level was decreased 7% compared with chemical fertilizer. Rice quality of the application levels of 80 and 100% SCB leachate levels was significantly better than those of chemical fertilizer and 130% level of SCB leachate. In conclusion, the 100% N application of SCB leachate was improved yield and quality of rice.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.372-381
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• 2013

The leaf growth and physiological characteristics of Forsythia saxatilis were investigated under different relative light intensities (RLI) and fertilization levels in order to find out the optimum environmental conditions for in-situ restoration. RLI and fertilization were four levels (30%, 43%, 63% of full sun and full sun) and three levels (non-fertilization, 2 times and 3 times of average forest soil in Korea), respectively. According to the increase of fertilization level under all RLI, leaf area increased and leaf dry weight and the ratio of leaf dry weight to leaf area decreased. As the fertilization level increased, photosynthetic pigment contents such as chlorophyll a, b and carotenoid under all RLI decreased. And pigment contents were the highest under full sun in the same fertilization level. Foliar nitrogen content under fertilization was higher than that under non-fertilization, and chlorophyll/nitrogen ratio decreased with the increase of fertilization level under all RLI. The increase of photosynthetic rate was observed with the increase of fertilization level at 63% of RLI and full sun, and dark respiration rate under fertilization was lower than under non-fertilization. Apparent quantum yield was lower at non-fertilization than that of fertilization, and it was highest at 63% of RLI under the same fertilization level. In conclusion, leaf growth and physiological characteristics of F. saxatilis could be improved under higher light conditions and fertilization.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.63-74
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• 2012

This experiment was carried out to investigate the effect of different stocking rate on growth, cast production and conversion efficiency of organic matter to tissues of earthworm. The carbon and nitrogen ratio (C/N) of tested Korean cow manure was 25.1, it was estimated an adequate ratio as feed for earthworms. The different stocking rates were 1:8(S-1), 1:16(S-2), 1:32(S-3) 1:64(S-4) 1:128(S-5) and 1:256 (S-6) as the ratios of earthworm fresh weight to biomass of Korean cow manure, respectively. A stocking rate of 1:32(S-3) was obtained a significantly highest values of increasing rate and conversion efficiency of organic matter to earthworm tissues. The mean values of increasin g rate of fresh weight and conversion efficiency of organic matter to earthworm tissues were 10.63 mg/day and 6.65% at the ratio of 1:32(S-3) with a rearing volume was $56.6cm^3$. A stocking rate of 1:8(S-1) was obtained a highest ratio of vermicasts, but showed a negative values of increasing rate and conversion efficiency of organic matter to earthworm tissues, it may due to severely food competition between individuals during the rearing periods. The pH, total nitrogen, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with stocking rate. Especially, available phosphorus, cation exchange capacity and exchangeable cations of vermicasts tended to increase with rearing progressed. Vermicasts have the potential for improving plant growth when amended to container medium and soil according to increased availability of nutrients and improved physicochemical properties.