• Journal of Korean Society on Water Environment
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• v.36 no.2
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• pp.109-115
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• 2020

Recently, since impervious areas have increased due to urban development, the water cycle system of urban watersheds has been destructed. Hence, researches on LID (Low Impact Development) technique have been conducted to solve such problems environmentally. In order to verify suitability with the scale and arrangement of LID technique, the runoff reduction effect of the LID technique should be analyzed per small watershed unit. In this study, pre-post difference of the runoff by applying the LID was estimated using the rational method and rainwater treatment capacity equation. As a result, the runoff before and after the application of LID were estimated as 22,533.5 ㎥ and 14,992.1 ㎥, respectively. In addition, rainfall-runoff simulations were carried out using SWMM to evaluate the efficiency of the LID technique. The SWMM simulation results showed that the runoff before and after the application of LID were 21,174 ㎥ and 15,664 ㎥, respectively. Based on the results of the two methods, the scale and arrangement of the LID technique were revised in order to maximize the effect of the water cycle improvement. Rainfall-runoff simulations were carried out using the SWMM with the revised LID techniques. As a result, despite 34.8 % reduction of pervious pavement area, the rate of runoff reduction increased by 2.1 %. These results indicate that designing the scale and arrangement of LID technique, while considering the total amount of inflow entering into each LID techniques, is essential to effectively achieve the goals of runoff reduction in urban development.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.347-355
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• 2006

Anyang Stream including its main branch is the biggest branch stream of Han River in Korea. The geological and geomorphological characteristics were investigated to the affected area of Anyang Stream, in which rainfall characteristic was analyzed. The water quality surveyed that the analysis of water pollution used to biotic index and biological water pollution. The rainfall pattern in this area was like to that of typical Korea, but the rate of trigger and runoff during summer season(June~August) is more higher than mean of Korea. Before 2003, a dried stream is severe status, which was due to abundant runoff, but this status are improved. After 1997, water quality of stream is recovering status such as water pollution of stream steeply decreased. Especially after 2003, this trend is more quickly improved. Although, owing to the increasing of a T-N and SS at upstream wastewater were due to bad collection of industrial factories, livestock's and mans living, the water quality worsted at upstream. Water quality in total section of main stream was severely contaminated that water-quality limit is 5 with polysaprobic by water self-purification. That of main branch was 1~3limits with ${\alpha}$- and ${\beta}$-mesosaprobic in Anyang city area, But water quality in all area about another branch of Anyang stream except Anyang city area was almost under of 3 grades. Though trying of Anyang city for recover movement(completion of 2nd Sewage Treatment Plant and Water supply pipe system) on Anyang stream, water pollution states of upper branch in Anyang stream was not better than its of 2002 because it may be difference of control area on other cities.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.791-800
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• 2005

An ILLUDAS-NPS model was developed which is able to compute pollutant loadings and the concentrations of water quality constituents. This model is based on the existing ILLUDAS model, and added for use in the water quality analysis process during dry and rainy periods. For dry period, the specifications of coefficients for discharge and water quality were used. During rainfall, we used the daily pollutant accumulation method and the washoff equation for computing water quality each time. According to the results of verification, the ILLUDAS-NPS model provides generally similar outputs with the measured data on total loadings, peak concentration and time of peak concentration for three rainfall events in the Hong-je Basin. In comparison with the SWMM and STORM models, it was shown that there is little difference between ILLUDAS-NPS and SWMM.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.10-15
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• 2016

In this research, the environmental effects of rain garden when applied to a stormwater runoff originated from a rooftop were evaluated. The rain garden that was utilized as LID represents less than 1% of the catchment area that it drains. Storm event monitoring was conducted from March 2012 to August 2014 on a total of 19 storm events. In the 19 storm events that was monitored only 32% produced an outflow which has a mean rainfall characteristic of approximately 25 mm. With the application of rain garden, hydrologic improvement was observed as the facility exhibit a delay and reduction in the production of runoff and peak flows as the rainfall progresses. Furthermore, in terms of pollutant reduction, it was observe that the rain garden showed a generally satisfactory performance in reducing pollutants. In addition to this, the rain garden also has additional attributes that adds to the aesthetic appeal of the surrounding environment as well as in the lives of the people. The findings of this research will help in the further improvement and reinforcement of LID designs.

• Korean journal of applied entomology
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• v.17 no.2 s.35
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• pp.81-87
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• 1978

Late blight incited by Phytophthora infestans (Mont.) de Bary, is an important problem for seed potato prodcution in Korea. At the alpine Daekwanryeong area, unprotected potatoes are often defoliated within 14 days after late blight is first observed in the field. Since regular spraying can control late blight, the forecasting service is needed for timely initiation of the spraying program. Climatological data and notes on late blight incidence were recorded during 1970-1977 at the Alpine Experiment Station. The moving graph method using 7-day average mean temperature and 7-day total rainfall did not give highly accurate forecasts. Adding data on relative humidity and 7-day average minimum temperature increased the usefulness of the moving graph. Yields of late blight susceptible varietieties in sprayed plots were related to late blight occurrence and to the rainfall distribution pattern.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.625-638
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• 2013

Recently, the occurrences of droughts have been increased because of global warming and climate change. Water resources that mostly rely on groundwater are particularly vulnerable to the impact of precipitation variation, one of the major elements of climate change, are very sensitive to changes in the seasonal distribution as well as the average annual change in the viewpoint of agricultural activity. In this study, the status of drought for the present and future on Jeju Island which entirely rely on groundwater using SPI and PDSI were analyzed considering regional distribution of crops in terms of land use and fluctuation of water demand. The results showed that the precipitation distribution in Jeju Island is changed in intensity as well as seasonal variation of extreme events and the amount increase of precipitation during the dry season in the spring and fall indicated that agricultural water demand and supply policies would be considered by regional characteristics, especially the western region with largest market garden crops. Regarding the simulated future drought, the drought would be mitigated in the SPI method because of considering total rainfall only excluding intensity variation, while more intensified in the PDSI because it considers the evapotranspiration as well as rainfall as time passed. Moreover, the drought in the northern and western regions is getting worse than in the southern region so that the establishment of regional customized policies for water supply in Jeju Island is needed.

• The Korean Fashion and Textile Research Journal
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• v.19 no.4
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• pp.434-447
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• 2017

This study investigated the effects of influencing factors on the sales volume of apparel products. Based on previous studies, weekend effect, discount rate, and meteorological factors including daily average temperature, rainfall, sea level pressure, and fine dust were selected as independent variables to calculate their effects on sales quantity of apparel products. The daily sales data during 2015 - 2016 were collected from casual brands and outdoor brands which "A" apparel manufacturing company had operated. The actual data of "A" company were analyzed using SAS(R) 9.4 and SAS(R) Enterprise Miner 14.1. The results of this study were as follows: First, the influencing factors on total sales volume of apparel products were proved to be the weekend effect, discount rate, and fine dust. Second, the analysis of influencing factors on sales volume of apparel products according to season showed: 1) In casual brands, the average temperature had a significant influence on the sales volume of spring/summer products, and the sea level pressure affected the sales volume of summer/fall/winter products significantly. 2) In outdoor brands, the average temperature and the fine dust had a significant influence on the sales volume of all season's products. The sea level pressure affected the sales volume of summer/fall/ winter products significantly. The weekend effect and the discount effect affected the sales volume of apparel products partly. Third, the effect of rainfall was not proven significant, which was different from the results of past studies.

• The Korean Journal of Mycology
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• v.35 no.1
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• pp.11-27
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• 2007

This study was conducted to investigate the diversity of higher fungi in NaeJangSan National Park from April 2004 to November 2006. The obtained results from investigation were as follows. The total of 5 classes, 19 orders, 60 families, 168 genera and 418 species (including 10 families, 13 genera and 15 species unrecorded) including saprophytic and ectomycorrhizal fungi was investigated. The higher fungi were classified into 47 families, 143 genera and 384 species in Basidiomycotina, 9 families, 19 genera and 28 species in Ascomycotina and 4 families, 6 genera and 6 species in Myxomycota. It was turned out that most of the higher fungi belong to Hymenomycetidae in Basidiomycotina, for which 34 families 122 genera, and 353 species were observed. Dorminant species belonged to Tricholomataceae(64 species) Russulaceae(39 species), Polyporaceae(36 species) and Boletaceae(36 species). The mushroom occurrence of higher fungi was closely related to climatic conditions such as high air temperature and lots of rainfall from July to September. The environment which has a favorable influence of mushroom occurrence was air temperature, relative humidity and rainfall of climatic environment.

• Environmental Engineering Research
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• v.18 no.2
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• pp.85-90
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• 2013

This study is an attempt to quantify rainwater utilization and miscellaneous water demand in Tokyo's 23 special wards, the core of the urban area in Tokyo, Japan, in order to elucidate the potential of further rainwater utilization. The rainwater utilization for miscellaneous appropriate water demands, including toilet flushing, air conditioning, and garden irrigation, were calculated for six different types of building: residential house, office, department store, supermarket, restaurant, and accommodation. Miscellaneous water demands in these different types of building were expressed in terms of equivalent rainfall of 767, 1,133, 3,318, 1,887, 16,574, and 2,227 (mm/yr), respectively, compared with 1,528 mm of Tokyo's average annual precipitation. Building types, numbers and its height were considered in this study area using geographic information system data to quantify miscellaneous water demands and the amount of rainwater utilization in each ward. Area precipitation-demand ratio was used to measure rainwater utilization potential for miscellaneous water demands. Office and commercial areas, such as Chiyoda ward, showed rainwater utilization potentials of <0.3, which was relatively low compared to those wards where many residential houses are located. This is attributed to the relatively high miscellaneous water demand. In light of rainwater utilization based on building level, the introduction of rainwater storage mechanisms with a storage depth of 50 mm for six different types of buildings was considered, and calculated as rainfall of 573, 679, 819, 766, 930, and 787 (mm), respectively. Total rainwater utilization using such storage facilities in each building from 23 wards resulted in the retention of 102,760,000 $m^3$ of water for use in miscellaneous applications annually, and this volume corresponded to 26.3% of annual miscellaneous water demand.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.294-299
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• 2006

The Ministry of Environment in Korea has introduced Total Pollution Load Management System (TPLMS) in major 4 large rivers to protect the water quality from possible pollutants. In order to successfully achieve the TPLMS, the nonpoint source should be controled by applying the best management practices in highly polluted areas. Of the various nonpoint sources, the highways are stormwater intensive landuses because of its high imperviousness and high pollutant mass emissions. The EMC (Event Mean Concentration) is an important parameter to correctly determine the pollutant mass loadings from nonpoint sources. However, it has wide ranges because of various reasons such as first flush phenomenon, rainfall and watershed characteristics. Even though the EMC is closely related to the first flush phenomenon, the relationship have not proven until present. Therefore, in this paper, the dynamic EMC method will be introduced to clearly make the relationship between EMC and first flush phenomenon. Also by applying the dynamic EMC method to monitored data, we found that the highly concentrated stormwater runoff was washed off within 20~50 minutes storm duration. The first flush criteria for economical treatment was also determined to 5~10 mm (mean=7.4 mm) as a cumulative rainfall.