• Journal of Wetlands Research
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• v.18 no.4
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• pp.350-356
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• 2016

The biggest factor in the success of breeding animals is selection of foods, which is determined by quality and quantity of habitats(Newton, 2003), in the case of This high biomass wetlands as an indicator of ecosystem function about Common Kestrel's choice of hunting area is expected to be an important clue of quality and quantity of habitats. For this study, it is divided into four types(Glasslands, Paddy fields, Dry fields, Rparian land) about Common Kestrel's hunting area in Yugu-eup, Gongju-si, Chungcheongnam-do, Recorded the behavior of Common Kestrel for three years during the breeding season from March to June(2014~2016). Result of investigation, hunting area showed a high hunting behavior in riversides and flight-hunting was frequently investigated from may to June. In addition flight-hunting's main food acquisition is mammal(the vole), while perching behavior's main food acquisition is insect according to the fact flight-hunting were mainly done in riversides, perching behavior were highly investigated than flight-hunting at glasslands and paddy fields and dry field. Hunting spot's coverage rate of plants covering the ground showed differences depending on hunting areas, but height of plants were not significant. Height of the plant according to hunting methods of flight-hunting to catch mammal(vole) was analyzed to prefer lower height than perching behavior Based on these results riversides are considered as a very important environmental factors for Common Kestrel's prey selection in breeding session.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.115-119
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• 1968

1. The basic investigations on soil textures, water holding capacity, pH, exchangeable calcium, and organic matter contents in four species bed were conducted in order to improve the natural flat for the bivalve beds. 2. It was statistically significant that there were differences in the soil textures among all beds of four species, D. japonica, C. sinensis, M. veneriformis, and T. philippin-arum. 3. There was no significant difference in water holding capacity, pH, and exchange-able calcium contents among different bivalve beds statistically, 4. It was highly significant that there were diffences in soil organic matter content among all groups of beds except that of D. japonica - C. sinensis. 5. It is considered that that soil textures and soil organic matter contents are most important factors to restrict the distribution of each species bivalve within a certain limited area of tidelands.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.375-383
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• 2023

To determine the cause of the population decline in Gobiobotia naktongensis, substrate preference and burying behaviour were investigated in this study. In general, the species was shown to prefer a substrate size of 1 mm or less, depending on the flow. In addition, the burying depth varied according to the size of the fish and increased with a decrease in water temperature. Our findings showed that the main cause of the population reduction was the physical changes in the substrate structure due to the dams or barrages construction. Notably, the accumulation of silt and mud in the substrate upon the formation of an upstream lentic water region for structural construction and bed armouring caused by scouring and reduced downstream inflow of fine sediment were deterministic in the fish habitat changes, causing problems in burying. As sand substrate structure is critical for the survival and inhabitation of psammophilous species, efficient strategies should be developed with proper habitat management to reduce the anthropogenic damage

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.188-195
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• 2010

The Abundance of zooplankton was studied in the pelagic and the littoral zone in four shallow reservoirs along with the Nakdong river basin of S. Korea. In the pelagic zone, there was a higher zooplankton density ($477.5{\pm}312.4$ ind. $L^{-1}$) than in the littoral zone during our study period (t=2.337, p<0.05). Overall, Rotifers were the most abundant group in the studied reservoirs. However, there are no significant correlations between the pelagic and the littoral zone in physical and chemical parameters. In the pelagic and the littoral zone, zooplankton density usually increased with increasing density of aquatic plants in the littoral zone. However, this study showed different trends. Although macrophyte abundance was higher in the littoral zone than in the pelagic zone, zooplankton abundance was higher in pelagic zone. Moreover, when macrophytes (Trapa japonica and Spirodela plyrhiza) covered the complete water surface of the reservoir, zooplankton abundance was higher. It appears that comparisons between the pelagic and the littoral zone give important cues on the selection of habitats by zooplankton. It is assumed that a higher density of aquatic plants does not always imply a higher density of zooplankton in the littoral zone. Furthermore, when the water surface was covered with aquatic plants, the zooplankton communities showed the highest density in the pelagic zone. These results imply that habitat selection of the zooplankton community (Rotifers) is influenced by aquatic plant density with an associated decrease in predation pressure during summer.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.516-525
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• 2011

We studied the influence certain environmental factors (proximity of roosting site, roads, and residential areas) have on the spatial distribution of cranes in the Cheorwon, Korea. Using a range finder and GPS, data were collected from January to February 2007 and were subsequently evaluated with ArcGIS. The size of the cranes' wintering habitat was estimated to be 7$76.9km^2$. Five hundred and fifty-five flocks of cranes were observed and detailed distributions were collected. Feeding distribution of the cranes showed clustered distribution, however, no tendencies of spatial autocorrelation were apparent. Adjacent regions with paved roads and residences showed lower densities than other areas. Distances at which paved roads and residential areas induced changes in feeding flock densities were 1500m and 1750m, respectively. Feeding flock density decreased with increased distance from roosting site. Feeding flock density of the two crane species did not increase as distance from roads increased, however, the density of individuals showed a significant increasing tendency with increased distance from roads. In both species, density of feeding flocks and individuals significantly increased with increasing distance from residential areas. In Red-crowned Cranes, the density of feeding flocks and individuals significantly decreased with increasing distance from roosting site, however, in the case of White-naped Cranes, there was an even distribution in density of feeding flocks and individuals.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.229-234
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• 2008

XBRL is fundamentally defined as a structure that enterprises expand based on KGAAP 2.1 developed by the Korea branch of XBRL. Each enterprise selects its type of business and must check and choose the tag suitable to each enterprise. Since a complicated part such as expanding tag exists, there is a difficulty to prepare document through the step of tag expansion and data input. Although the expressive way of style provides the standards using the presentation structure and label structure provided fundamentally by XBRL, there is a complicated problem of using XBRL Processor. The electronic public disclosure system of the Financial Supervisory Service (DART) and Korea Exchange (KIND, KEDIS) use the Markup Language of SGML, XML and XBRL as format language. The procedure of defining document and process method vary in accordance with the characteristics of each language. This study analyzes the effect by step in accordance with format language of each electronic disclosure system and studies a direction of format language.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.59-64
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• 2008

We need to use the strength of each Species Distribution Model(SDM) because presence location data were only collected due to time and economic limitations in Korea. This study investigated and compared GAM(Generalized Additive Model) which is one of presence-absence models with Maxent(Maximum Entropy Model) which is one of presence only models according to location data(presence/absence data). The target species was Fisher(Martes pennanti) which is an endangered species in California, USA. We implemented environmental data such as topography, climate and vegetation, and applied models to sub-regions and study area. The results of this study were as follows. Firstly, GAM which used real presence and absence data was better than GAM which used pseudo-absence data and Maxent which used presence-only data. Secondly, Maxent was better than GAM when presence-only data were used. Lastly, each model which applied to different regions didn't predict other area well due to the difference of habitat environment and over-predicted outside of study area. We need to select an optimal model to predict a suitable habitat according to the type and distribution of location data.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.247-256
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• 2012

We evaluated the landscape ecological value of selected minefields and wetland patches as a habitat of the forest bird community. The avian fauna of three minefields of 8.5ha, 17.4ha, and 40.6ha were evaluated by comparing that of three control sites of mountain area. Average number of forest bird species, number of individuals, species diversity index, species richness, and species evenness were analyzed according to the size of patch and environmental characteristics such as the presence of wetland and connectivity. Community similarity was evaluated between test and control plots. Avian fauna can be summarized as follows. First, 63 species were recorded, and the sum of maximum counts was 828 individuals. Species diversity index was 3.8, and the species richness was 9.2. Species evenness was 93.3. Second, small, isolated forest patch had a low average number of species and individuals as expected. But, small forest patches with streams had higher bird density than patches without water surface. Third, forest patches with marsh wetland were evaluated as lower habitat quality than forest patches with stream wetland in terms of the number of bird species per unit area, number of individuals per unit area, species diversity index, species richness index, and species evenness. Finally, Community similarity of the small forest patches with streams was similar with large connected forest. As a result, lowland forest patch was shown the good quality for the forest bird community in spite of small extents, and community structure was similar with mountain forest bird community. Thus, riparian forest restoration could improve the biodiversity of the forest bird community.

• Journal of Environmental Impact Assessment
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• v.30 no.1
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• pp.13-23
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• 2021

In this study, we performed a Random Walker analysis to predict the Major Movement Paths of otters. The scope of the research was a simulation analysis with a radius of 7.5 km set as the final range centered on the Ansim-wetland in Daegu City, and a field survey was used to verify the model. The number of virtual otters was set to 1,000, the number of moving steps was set to 1,000 steps per grid, and simulations were performed on a total of 841 grids. As a result of the analysis, an average of 147.6 objects arrived at the boundary point under the condition of an interval of 50 m. As a result of the simulation verification, 8 points (13.1%) were found in the area where the movement probability was very high, and 9 points (14.8%) were found in the area where the movement probability was high. On the other hand, in areas with low movement paths probabilities, there were 8 points (13.1%) in low areas and 4 points (6.6%) in very low areas. Simulation verification results In areas with high otter values, the actual otter format probability was particularly high. In addition, as a result of investigating the correlation with the otter appearance point according to the unit area of the evaluation star of the movement probability, it seems that 6.8 traces were found per unit area in the area where the movement probability is the highest. In areas where the probability of movement is low, analysis was performed at 0.1 points. On the side where otters use the major movement paths of the river area, the normal level was exceeded, and as a result, in the area, 23 (63.9%), many form traces were found, along the major movement paths of the simulation. It turned out that the actual otter inhabits. The EN-Simulator analysis can predict how spatial properties affect the likelihood of major movement paths selection, and the analytical values are used to utilize additional habitats within the major movement paths. It is judged that it can be used as basic data such as to grasp the danger area of road kill in advance and prevent it.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.22-35
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• 2005

내분비계 장애물질 (Endocrine Disruptors: EDs)이란 ‘내분비 기능에 변화를 일으켜, 생체 또는 그 자손의 건강에 위해한 영향을 미치는 외인성 물질’로서 세계야생생물보호기금 (World Wildife Fund: WWF)의 목록에는 67 여종, 일본 후생성에서는 142 여종의 물질을 내분비계 장애물질로 분류하고 있다. 이렇게 분류된 내분비계장애물질 가운데에는 많은 종류의 농약이 포함되어 있으며, 이들이 자연상태계에 미치는 영향에 대한 많은 보고가 있다. 양서류는 먹이연쇄의 중위포식자로 내분비계 장애물질의 순환 및 생채축적 회로에서 중요한 위치를 갖는다. 또한 농경지나 계류 등에 서식하며 산란하는 습성이 있다. 이러한 서식지는 농약 등에 노출받기 쉬우므로 환경오염평가 대상동물로 중요하다. 본 연구에서는 국내에서 사용되고 있는 제초제, 살충제 등이 양서류 발생에 미치는 영향을 평가하고, 이들 물질에 의한 노출을 평가할 수 있는 biomarker 유전자를 발굴하고자 하였다. 우리나라 전역에 많이 분포하는 무당개구리(Bombina orientalis)의 초기 배아발생 과정에서 이들 농약을 처리하였을 때, 물질의 종류에 따라 정도의 차이는 있으나 농도 의존적으로 배아 및 올챙이의 치사율이 높게 나타났다. 또한 농약은 배아 및 올챙이의 기형을 유발하였다. 기형의 종류는 농약에 따라 서로 상이한 형태로도 나타났으나, 특히 몸통휨 또는 꼬리휨등의 척추골 기형이 많이 나타났다. 환경 위해성 평가 biomarker 유전자로서 골격계 형성에 관여하는 Sox9 유전자를 선택하였다. 무당개구리에서 처음으로 Sox9 유전자를 동정하였으며, 농약을 처리한 실험군에서의 Sox9 유전자의 발현 양상은 대조군에 비하여 높게 나타났다. 본 연구결과 생태계에서 내분비계 장애물질의 위해성 평가를 위해 양서류 초기배아의 치사 및 기형의 정도를 관찰하는 방법이 유효할 것으로 사료된다. 또한 야생동물의 biomarker 유전자를 발굴과 이를 이용한 위해성 평가는 더욱 정밀한 평가법으로 유용할 것이다.