• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.576-587
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• 2012

As being actual physiognomical vegetation on Daegwang sand dune in Imjado, the widest area is occupied by Pinus thunbergii community planted as windbreak forest whereas those communities such as Robinia pseudoacacia community, Elymus mollis community, Imperata cylindrica var. koenigii - Elymus mollis community, Carex kobomugi community, Ischaemum antephoroides community, Imperata cylindrica var. koenigii community, Phragmites communis community, Imperata cylindrica var. koenigii - Calamagrostis epigeios community occupy as band shape or patch. According to the result of the data collected and analyzed based on phytosociological method regarding 74 plots of survey area, the species composition of Daegwang sand dune vegetation is classified total 10 vegetation units comprises 7 communities and 5 groups. The 7 communities are classified into Pinus thunbergii community, Robinia pseudoacacia community, Rosa rugosa var. rugosa community, Ischaemum antephoroides community, Carex kobomugi community, Calamagrostis epigeios community, and the sub-units of Pinus thunbergii communities are classified into 3 groups of Pteridium aquilinum var. latiusculum group, Elymus mollis group, Pinus thunbergii topical group and the sub-units of Calamagrostis epigeios communities are classified into 2 groups of Phragmites communis group, Calamagrostis epigeios tipical group. The zonation of vegetation from coastal line indicated with the order of Elymus mollis - Carex kobomugi, Carex pumila, Lathyrus japonicus - Calystegia soldanella - Vitex rotundifolia, Lathyrus japonicus, Ischaemum antephoroides - Rosa rugosa var. rugosa. According to the analysis result of longitudinal section, it was found to be those types with wide width herbaceous vegetation of foredune, smooth slope of foredune, lots of dune ridges with no structure were less vulnerable to erosion of sand dune and advantageous to its recovery.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.799-813
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• 2011

Increasing mountain biking (MTB) in forest recreation areas is changing the behavioral patterns in the areas where hiking has been a dominant activity, and it may cause ecological and social impacts to the areas. This study examined hikers' perceived conflicts by MTB including the relationship between socio-demographic and visiting characteristics and perceived conflict. On-site survey was conducted in Mudeungsan Provincial Park (MPP), Korea, during September, 2010. Out of 388 hikers participated in the survey, 374 responses were used for data analysis. 30.2% of the respondents encountered or saw MTB (avg.: 1.7 times) in MPP. Overall, 77.1% of respondents thought MTB in MPP was a problem. 73.5%~83.2% of respondents perceived conflict by four major MTB behaviors (e.g., too fast running MTB in trails; MTB bikes occupying trails; MTB bikes passing by hikers too closely; MTB bikers doing unpleasant behaviors to hikers). Based on the type of conflict, 48.5~62.4% of respondents fell in the type of "social values conflict (SVC)", 11.1~32.4%, "interpersonal conflict (IC)", and 16.8~26.6%, "no conflict (NC)", respectively. Types of conflicts were related with sociodemographic (e.g., gender, age, education) and visiting characteristics (e.g., number of visits, experience of encountering MTB). Such relationships were nonexistent in most cases when the "experience of encountering MTB" was controlled.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.85-95
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• 2020

According to the standard guidelines of design flood (MLTM, 2012; MOE, 2019), the design flood is calculated based on past precipitation. However, due to climate change, the frequency of extreme rainfall events is increasing. Therefore, it is necessary to analyze future floods' volume by using climate change scenarios. Meanwhile, the standard guideline was revised by MOE (Ministry of Environment) recently. MOE proposed modified Huff distribution and new CN (Curve Number) value of forest and paddy. The objective of this study was to analyze the change of flood volume by applying the modified Huff and newly proposed CN to the probabilistic precipitation based on SSP and RCP scenarios. The probabilistic rainfall under climate change was calculated through RCP 4.5/8.5 scenarios and SSP 245/585 scenarios. HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System) was simulated for evaluating the flood volume. When RCP 4.5/8.5 scenario was changed to SSP 245/585 scenario, the average flood volume increased by 627 ㎥/s (15%) and 523 ㎥/s (13%), respectively. By the modified Huff distribution, the flood volume increased by 139 ㎥/s (3.76%) on a 200-yr frequency and 171 ㎥/s (4.05%) on a 500-yr frequency. The newly proposed CN made the future flood value increase by 9.5 ㎥/s (0.30%) on a 200-yr frequency and 8.5 ㎥/s (0.25%) on a 500-yr frequency. The selection of climate change scenario was the biggest factor that made the flood volume to transform. Also, the impact of change in Huff was larger than that of CN about 13-16 times.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.565-577
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• 2019

The purpose of this study was to understand the factors influencing the decline and the patterns of changes in Abies nephrolepis populations on Mt. Seorak. We installed permanent quadrats in the areas of the Gwittagicheongbong (peak), Gwanmoneungseon (ridge), and the Seorak Falls and have monitored the community structure, population dynamics, radial growth, and vitality in the quadrats since 2009. Excluding the Seorak Falls, the three research sites showed a three-layer structure in which the low-tree layer forms the canopy. Major tree species were Khingan fir, Korean arborvitae, Mongolian oak, Erman's birch, and Korean maple. The significance of Khingan fir in Seorak Falls decreased from 45.3% in 2009 to 36.8% in 2018. The number of shoots ($DBH{\geq}5cm$) was highest at 1,800 individuals/ha and 1,700 individuals/ha at the Gwittagicheongbong 2 and the Gwanmoneungseon, respectively. The mortality rates over the past 10 years were very high, at 38.3% and 35.3%, respectively, in the Gwittagicheongbong 1 and Seorak Falls. The most stable inverse J-shaped distribution in the Gwittagicheongbong 1 area was shown in the size-frequency distribution of the Khingan fir populations. The average annual ring growth of the Khingan fir was 0.96 ~ 1.73 mm/year, and the ring growth tended to decrease in the areas of Gwittagicheongbong 1, Gwanmoneungseon, and Seorak Falls, where the vitality was low. If the monitoring process continues, it will be possible to obtain basic data for the conservation and management of subalpine vegetation.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.243-252
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• 2015

This study was performed to establish a production system for in situ and ex situ conservation of Elsholtzia minima Nakai, an endemic plant grown in Jeju Island. Moreover, this study aimed to identify root-growth characteristics according to the use of pre-treatment agents and seedling growth effect according to fertilizer application. The mean temperature was similar in greenhouse and vinyl-moist chamber, but air humidity was higher in vinyl-moist chamber than in greenhouse. After stem planting of Elsholtzia minima Nakai, initial root growth was observed after 10 days in greenhouse and after 7 days in vinyl-moist chamber. Root growth rate was more rapid in vinyl-moist chamber. Moreover, survival rate, root growth rate and root number was slightly higher in vinyl-moist chamber than in greenhouse, indicating that vinyl-moist chamber is more effective in plant growth. When pre-treatment agents were used to remove root growth-inhibiting substances, a higher root growth rate of more than 95% was found in pre-treatment groups, excluding the group treated with AgNO₃ at 77.5%. Thus, Elsholtzia minima Nakai is thought to have less root growth inhibitors. In the analysis of nitrogen application rate and Osmocote application by seedling container, a difference was found in survival rate and growth according to application rate and container conditions. When Osmocote, a slow release fertilizer, was applied to the soil surface around each culture container, survival rate and the growth of aerial and root parts were most favorable. Thus, Osmocote fertilizer is thought to be desirable for seedling propagation of Elsholtzia minima Nakai.

• Journal of Korean Society of Disaster and Security
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• v.14 no.2
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• pp.13-23
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• 2021

This study intended to assess the reliability of topographic data using satellite imaging data. The topographical data using actual instrumentation data and satellite image data were established and applied to the rainfall-leak model, S-RAT, and the topographical data and outflow data were compared and analyzed. The actual measurement data were collected from the Water Resources Management Information System (WAMIS), and satellite image data were collected from MODIS observation sensors mounted on Terra satellites. The areas subject to analysis were selected for two rivers with more than 80% mountainous areas in the Han River basin and one river basin with more than 7% urban areas. According to the analysis, the difference between instrumentation data and satellite image data was up to 50% for peak floods and up to 17% for flood totals in rivers with high mountains, but up to 13% for peak floods and up to 4% for flood totals. The biggest difference in the video data is Landuse, which shows that MODIS satellite images tend to be recognized as cities up to 60% or more in urban streams compared to WAMIS instrumentation data, but MODIS satellite images are found to be less than 5% error in forest areas.

• Convergence Security Journal
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• v.21 no.1
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• pp.191-200
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• 2021

Artificial intelligence technology is developing in an environment where a lot of data is produced due to the development of computing technology, a cloud environment that can store data, and the spread of personal mobile phones. Among these artificial intelligence technologies, the deep neural network provides excellent performance in image recognition and image classification. There have been many studies on image detection for forest fires and fire prevention using such a deep neural network, but studies on detection of cigarette smoking were insufficient. Meanwhile, military units are establishing surveillance systems for various facilities through CCTV, and it is necessary to detect smoking near ammunition stores or non-smoking areas to prevent fires and explosions. In this paper, by reflecting experimentally optimized numerical values such as activation function and learning rate, we did the detection of smoking pictures and non-smoking pictures in two cases. As experimental data, data was constructed by crawling using pictures of smoking and non-smoking published on the Internet, and a machine learning library was used. As a result of the experiment, when the learning rate is 0.004 and the optimization algorithm Adam is used, it can be seen that the accuracy of 93% and F1-score of 94% are obtained.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.618-638
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• 2018

This study examined the vegetation structure in the ridge of the Hannamgeumbuk-Jeongmaek and Geumbuk-Jeongmaek by selecting 7 sites(2 sites at Hannamgeumbuk-Jeongmaek and 5 sites at Geumbuk-Jeongmaek) in consideration of the environmental conditions and artificial influences and conducting the vegetation survey in the selected sites. The community classification based on TWINSPAN categorized the vegetation at Hannamgeumbuk-Jeongmaek into 8 groups: Quercus variabilis-Q. acutissima community, Pinus densiflora-Q. mongolica community, Pinus densiflora community, P. densiflora-Q. mongolica-Q. variabilis community, P. densiflora-Deciduous oaks community, P. koraiensis community, Q. mongolica-Q. variabilis community, and Larix kaempferi-P. koraiensis community. It also categorized the vegetation at Geumbuk-Jeongmaek into 9 groups: Quercus variabilis community, Deciduous broad-leaved community, Q. mongolica community, Pinus densiflora-Q. mongolica-Q. variabilis community, Q. acutissima community, P. densiflora-Q. acutissima-Q. variabilis community, P. densiflora-Q. mongolica-P. rigida community, P. densiflora-P. thunbergii-Deciduous oaks community, and P. koraiensis community. Two species, Quercus mongolica and Pinus densiflora, which are widely distributed in the ridges of the Jeongmaeks and Baekdudaegan in South Korea, were dominant in many of the surveyed sites. The appearance of planted Castanea crenata in some plots, although not in high population, suggests human intervention in most regions of the Hannamgeumbuk-Jeongmaek and Geumbuk-Jeongmaek in the past. The Gayasan area, which is part of the Geumbuk-Jeongmaek and where the maritime climate and continental climate overlap, showed Pinus thunbergii, reflecting the local climate characteristics.

• Journal of Korean Society on Water Environment
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• v.35 no.4
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• pp.316-331
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• 2019

Carbon dioxide($CO_2$) emission from rivers to the atmosphere is a key component in the global carbon cycle. Most of the rivers are supersaturated with $CO_2$. At a global scale, the amount of $CO_2$ emission from rivers is reported to be five-fold greater than that from lakes and reservoirs, but relevant data are rare in Korea. The objectives of this study is to estimate the $CO_2$ net atmospheric flux(NAF) from the upstream of Gangjeong-Goryeong Weir(GGW), Dalseong Weir(DSW), Hapcheon-Changnyeong Weir(HCW), and Changnyeong-Haman Weir(CHW) located in Nakdong River South Korea) using field and laboratory experiments and to apply data mining techniques to develop parsimonious prediction models that can be used to estimate $CO_2$ NAF with physical and water quality variables that can be collected easily. As a result, the study sites were all heterotrophic systems that often released $CO_2$ to the atmosphere, except when the algal photosynthesis was active.The median $CO_2$ NAF was minimum $391.5mg-CO_2/m^2$ day at GGW and maximum $1472.7mg-CO_2/m^2$ day at DSW. The $CO_2$ NAF showed a negative correlation with pH and Chl-a since the overgrowth of the algae consumed $CO_2$ in the water and increased the pH. As the parsimonious multiple regression model and random forest model developed, this study showed an excellent performance with the $Adj.R^2$ value higher than 0.77 in all weirs. Thus, these methods can be used to estimate $CO_2$ NAF in the river even if there is no $pCO_2$ measurement data.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.2
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• pp.133-145
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• 2019

This study was raised by the need to explain why the problems related to private parks have been sustained. In order to identify the fundamental cause, it is necessary to analyze the historical and institutional context of private parks. Therefore, the purpose of this study is to identify the direction of change in the private park system and to derive the characteristics of the system as it currently appears. The framework based on the historical institutionalism was divided into the Park Act (1967-1980), the former of Urban Park Act (1980-1993) and the late of Urban Park Act (1993-2005), and each was assessed using the analysis elements of the institutional environment and the outcomes of implementation. The analysis elements interpreted the path dependency, in which the inertia toward the choice of institution is maintained, despite the change in the environment. The institution took a special form of 'negative systeme' and secured profitability by expanding the types of park facilities while mitigating the criteria. Additionally, the designation of private park promoters as a landowner acted as a means of compensating those with property rights to unexecuted urban parks. The expectation effectiveness on urban park creation was insufficient and the environmental regulatory functions were weakened. Thus, historically, the private park system in Korea has experienced an 'institutional decoupling' as the purpose of the system and the results of actual outcomes are not consistent.