• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1120-1121
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• 2005

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.259-281
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• 2013

This research aims to analyze Baekdu mountain are with it's the east flowing streams which are the issues on the old maps. Also, it will analyze the eastern flows, Tomoon river; Boongye river; Dooman river, from Baekdu mountain which have been the border settlement issues since Josun dynasty. Also, it will analyze the north-eastern flows, Heukryong river; Songhwa river; Sockpyung river; Tomoon river; Boongye river; Dooman river, from Baekdu mountain which have been the border settlement issues since Josun dynasty. The mainly issued Baekdu mountain's north-eastern flows can be classified into six different flows by the classifications, it proves that there are various Baekdu mountain north-eastern flows on the old maps. the two streams theory of Tomoon and Doman river explains the perspective of the northern expansion, and the one stream theory expresses it by stating Boongye and Sockpyung river as the same one. However, in the case of the meaning of Boongye river is Haeran river on the middle of one stream theory map, there is no region expanding perspective but the same border perspective that Korean peninsula and China match. Boongye river is expressed into four different meanings. (1) It is the same river with Sockpyung and shows the regional expanding perception. (2) It is the same river with Tomoon and the down stream of Tomoon river.(3) It expresses the current name, Haeran river. (4) It simply means the river shows the boundary.

• Journal of Korean Society of societal Security
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• v.2 no.1
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• pp.75-80
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• 2009

The objectives of this research are to develop hazard prediction map S/W for mountain river road. This mountain river road disaster happens by debris flow, landslide, debris accumulation and this cause are locally rainfall and heavy rainfall. System is constructed to GIS base. This research app lied to Kangwondo. We developed protocol to analyze calamity danger in mountain district area and examined propriety system. Furthermore examined the DB required and expression plan for hazard map creation SW construction by mountain rivers road.

• Geomechanics and Engineering
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• v.22 no.2
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• pp.133-142
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• 2020

The evolution of the mining-induced fracture network formed during longwall top coal caving (LTCC) has a great influence on the gas drainage, roof control, top coal recovery ratio and engineering safety of aquifers. To reveal the evolution of the mining-induced stress and fracture network formed during LTCC, the fracture network in front of the working face was observed by borehole video experiments. A discrete element model was established by the universal discrete element code (UDEC) to explore the local stress distribution. The regression relationship between the fractal dimension of the fracture network and mining stress was established. The results revealed the following: (1) The mining disturbance had the most severe impact on the borehole depth range between approximately 10 m and 25 m. (2) The distribution of fractures was related to the lithology and its integrity. The coal seam was mainly microfractures, which formed a complex fracture network. The hard rock stratum was mainly included longitudinal cracks and separated fissures. (3) Through a numerical simulation, the stress distribution in front of the mining face and the development of the fracturing of the overlying rock were obtained. There was a quadratic relationship between the fractal dimension of the fractures and the mining stress. The results obtained herein will provide a reference for engineering projects under similar geological conditions.

• Journal of Environmental Impact Assessment
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• v.13 no.1
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• pp.21-31
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• 2004

Construction of highway would influence wildlife habitat being fragmented and deteriorated. It is inevitable to observe the death of animals that are killed by vehicles. Nonetheless the cause and status of animal roadkill have not been studied, and this study first attempted to analyze the roadkill in major highway in Korea. We collected 860 individuals of dead animals in Joongang Highway during 1996-2003. Among them Korean hare(Lepus sinensis) was totaled in 165 individuals(19.2%) with the highest figure; Korean racoon dog(Nyctereutes procyonoides) was 146(17.0%); Korean squirrel(Sciurus vulgaris) 56(6.5%); Korean roe deer(Capreolus capreolus) 26(3.0%). Domestic animals was totaled in 232 individuals(27.0%); domestic dog(Canis familiairis) 25, and domestic cat(Catus felis) 207. This study also categorized habitat as mountain-mountain, mountain-plain, mountain-river, plain-plain, plain-river, river-river in each side of the road. Habitat of mountain-plain was the heightest with 296(38.9%) individuals followed by mountain-mountain with 263(34.6%). This indicates that wild animals associated with mountain habitat was most influenced by the construction of roads. This study implied that we should mitigate the roadkill by designing artificial construction such as eco-bridge, fences along the sideway, and boxes under the highway, underdrain structure, etc. The monitoring and cause of habitat fragmentation with GIS approach should be followed to reduce the roadkill.

• Journal of Ecology and Environment
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• v.41 no.8
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• pp.213-222
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• 2017

Background: This study was conducted to assess the physicochemical water quality and the altitudinal distribution of low-temperature and mountain epilithic diatom (LTMD) community in Buk and Hangae streams that are located in Seorak Mountain with the height of 1708 m in Korea. And the community characteristics of LTMD found in the Buk and Hangae streams were compared to that of LTMD from the Han River system. Results: The physicochemical water qualities of Buk and Hangae streams were determined to be very clean. As a result of analyzing the community composition, 135 taxa of epilithic diatoms were determined, and 22 taxa appeared including Hannaea arcus var. subarcus which are known to have low-temperature and mountain ecological characteristics in the literatures. The relative frequencies of LTMD were 37.0~0.9% range from the upper to lower regions. Although Diatoma tenuis, Eunotia minor, and Gomphonema affine are known to be ubiquitous in streams and lakes, in this research, the three taxa were added into low-temperature and mountain epilithic diatom, since D. tenuis and E. minor appeared only in altitudes above 600 m, and G. affine had the highest relative frequency during spring and fall in altitudes above 700 m, when water temperature was around $10^{\circ}C$. Conclusions: Among the 24 taxa of low-temperature and mountain epilithic diatom (LTMD) (including the 3 taxa added in this study), 14 taxa (Diatoma hyemalis, D. mesodon, D. tenuis, Hannaea arcus, H. arcus var. subarcus, Ulnaria inaequalis, Eunotia bilunaris, E. implicata, E. minor, E. muscicola, E. silvahercynia, E. septena, Delicata delicatula, and Gomphonema affine) represented the characteristics of LTMD very well; they grow best in water temperatures below $15^{\circ}C$ in Buk and Hangae streams and Han River system.

• Journal of Korea Water Resources Association
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• v.47 no.12
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• pp.1165-1176
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• 2014

In a river bend the water surface is inclined by the centrifugal force toward the transverse section. If channel slope and flow rate increase, the gradient is rising generally. There are lots of the flood damage at the bends of mountain river because the flood water levels have exceeded frequently the levee levels which are added a free board to the design flood water level. Therefore the superelevation should be considered in designing the mountainous river bend. In present study it was proposed to estimate the superelevation at the bend of mountain river and the superelevation coefficient defined from multiplying the sub-factors. The values of the influence factors for the superelevation coefficient were suggested from analyzing the superelevation measured at the bends in Yangyangnamdae river and the hydraulic experiments in gravel-bed channel with a $90^{\circ}$ bend. The applicability of these methods to estimate the superelevation at the bends in mountain river was verified by the superelevation measured at the bend in Naerin river.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.3
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• pp.14-24
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• 2007

The purpose of this study was to investigate how the landscape characteristics and the physical factors of landscape would affect the preference for the Gapcheon in Daejeon Metropolitan City. The Gapcheon was divided in three sections of the outskirts, Expopark areas, and residential complexes. After selecting seven landscape points where the sections could be expressed best, photographs were taken both in the upstream and downstream direction. The questionnaire used to evaluate the river's landscape included 20 items of adverbs that described the form of the river and one item to rate the overall preference. By analyzing the 14 pictures taken, the occupancy rates of the landscape elements in terms of the sky, river, vegetation of the river, mountain, and artificial structures. Image factor analysis was conducted for each of the sections in order to analyze the landscape characteristics of the Gapcheon, and then regression analysis was conducted in order to analyze the relationships among the physical factors influencing the preference of the landscapes. The results were as follows : Factors that compose the visual characters of urban river were classified be the aesthetic factor, the emotional factor and the situation factor. These 3 factors showed a 65.8% total variance. The river landscape with the biggest preference was the one from the Daedeok Grand Bridge as the occupancy area of the mountain, sky, and river was large and distributed evenly and the vegetation of the river was in a good harmony with the surroundings. After carrying out regression analysis to examine the relationships between the visual preference of Gapcheon and the physical factors of landscape(the sky, river, vegetation of the river, mountain, and artificial structure), the following regressions model was made : PRE=5.906+0.017(river)-0.053(artificial structure)-0.060(vegetation of the river) (R-square=0.48).

• Geomechanics and Engineering
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• v.23 no.5
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• pp.467-480
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• 2020

The failure behavior and tensile strength of sandstone materials under different strain rates are greatly different, especially under static loads and impact loads. In order to clearly investigate the failure mechanism of sandstone materials under static and impact loads, a series of Brazilian disc samples were used by employing green sandstone, red sandstone and black sandstone to carry out static and impact loading splitting tensile tests, and the failure properties subjected to two different loading conditions were analyzed and discussed. Subsequently, the failure behavior of sandstone materials also were simulated by finite element code. The good agreement between simulation results and experimental results can obtain the following significantly conclusions: (1) The relationship of the tensile strength among sandstone materials is that green sandstone < red sandstone < black sandstone, and the variation of the tensile sensitivity of sandstone materials is that green sandstone > red sandstone > black sandstone; (2) The mainly cause for the difference of dynamic tensile strength of sandstone materials is that the strength of crystal particles in sandstone material, and the tensile strength of sandstone is proportional to the fractal dimension; (3) The dynamic failure behavior of sandstone is greatly different from that of static failure behavior, and the dynamic tensile failure rate in dynamic failure behavior is about 54.92%.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.439-445
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• 2022

Organic pollutants that contained in stream sediments have origins of mountain soil in natural and cattle manure in human activity. Nitrogen and carbon isotope analysis for mountain soil, cattle manure and stream sediment were performed for contribution evaluation of organic pollutants in Toil stream of Yeongju dam basin. Average carbon isotope ratio(δ¹³C) is -25.17‰, -22.34‰, and -26.39‰ for river sediments, cattle manure and mountain soil, respectively. Result of carbon isotope analysis suggests that river sediments are more affected by acid soils. Average value of the nitrogen isotope ratio (δ¹⁵N) is 9.46% for river sediment, 1.99% for mountain soil, and 19.53% for cattle manure. Result of nitrogen isotopic analysis show that contribution of cattle mature is slightly higher than that of mountain soil in Toil stream sediments.