• Computers and Concrete
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• v.16 no.1
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• pp.179-190
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• 2015

An experimental program has been carried out to investigate the effect of edge-slope on compressive strength of concrete specimens. In this study, effect of such slope was investigated by testing 100 standard cylinder specimens and 40 standard cubes. When molds are put on a slanted place, wet concrete starts to flow through the open end of mold. It keeps flowing until it reaches to a parallel surface with the place over which it was placed. That creates a sloped surface over the loading area. Experimental results revealed significant relationships between failure loads and slope of loading surface for cylinders. Angled cracks occurred in sloped cylinder specimens. Tension cracks occurred in cube specimens. Fracture mechanisms were also evaluated by using finite element analyses approach. Experiments yielded an exponential curve with bandwidth for cylinders. Average value of curve is $y={\frac{\pi}{2}}e^{-cf}$ between slope and compressive strength. Inclination is much effective parameter for cylinders than cubes.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.87-94
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• 2011

This paper is results of analyzing characteristics of landslides occurred in Wonju, Gangwondo, around July, 16 in 2006, caused by heavy rainfall and antecedent precipitation by two typhoons of Ewiniar and Bilis. The main causes of landslides were antecedent precipitation during July 8 to 15, resulting in weakening grounds by increasing the degree of saturation previously, and the heavy rainfall during July 15 to 16. Most of landslides in natural slopes were transitional failures occurred along the boundary between the residual weathered soil in shallow depth and the hard mother rock. From results of conclusive analyses regarding 28 sites in Wonju region where landslides occurred, the slope length of landslide, the slope width, and the slope area were less than 50m with 71% of frequency, 20m with 79% of frequency and $300m^2$ of 64% of frequency respectively. The average value of slope angle was $35^{\circ}$. The most probable direction of slope was found to be north because of topography and advancing direction of seasonal rain front.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.501-508
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• 2002

The percentage of a mountainous district in our country is comparatively high but the concern for rock mass has been disregarded for a long time. Especially for rock slope, the most important factors are geometric characteristics and their shear strength parameter. In this paper, parametric studies are performed using the distinct element computer program UDEC-BB for rock slopes. Parameters adopted in this paper are joint angle, spacing, persistence, aperture and shear strength parameters (JRC, JCS, basic friction angle). To estimate slope stability, shear strength reduction method is used. The most important factors affecting rock slope stability are joint angle and spacing. The relationship between average displacement calculated by UDEC-BB and safe factor by shear strength reduction method is researched.

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.59-67
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• 2012

In this paper, performances of solar hot water supply systems are parametrically analyzed with the variations of solar collector area, slope of collector and volume of storage. All simulations are conducted by using TRNSYS computer program. Average solar fractions, collector efficiencies and temperatures of storage are investigated monthly as well as annually. For system analysis, the maximum value of monthly average solar fractions has a limitation of 90 percent. As a result, the designed solar thermal system with $6m^2$ collector area, $50^{\circ}$ slope and $0.36m^2$ storage volume could provide almost an annual average solar fraction of 72 percent. By increasing the storage volume to $0.42m^2$, the annual solar fraction of system increases up to 73 percent.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.81-87
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• 1989

Many depth estimation techniques for magnetic exploration, such as the slope methods, graphica1 methods, spectral analysis, and Fourier ana1ysis have been published. Nevertheless, it appears that the half-slope method of Peters(1949)and the maximum-slop method of Vacquier et. al. (1951)are more popular and widely used by geophysicists in the hydrocarbon exploration industry. The slope methods are not only simpler and easier to use but are also genera1ly reliable. The spectral method is fast, effective, and powerful in the determination of an average depth. The often unreliable results produced from spectral techniques are attributed to their application to isolated magnetic anomaly cases. The reliability and limitations associated with the method are given in order to minimize problems and increase accuracy in the application of the method.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.263-275
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• 2022

We conducted this study to provide essential data for implementing restoration measures on the physical properties of the geology, topography, and soil of the landcreep areas in Yangpyeong-gun, Gyeonggi-do. The strata of the survey area comprised topsoil, weathered soil, weathered rock, and soft rock layers. The landcreep area, caused by colluvial debris, was located in a convex topography shape distributed as bedrock with shales and incorporated with sandstone. According to the measurement of the displacement meter, the surveyed area has crept from 1.1 mm to 6.5 mm during the recurrent landcreep between 1 July and 27 August, 2020. The landcreep had progressed over two directions (S65° W, E45° S, and E70° S) which were similar to the groundwater flow direction (E82.5° S and S16.8° W). The average slope of the landcreep area occurred on a gentle slope (19.3°), lower than the average slope of the mountain area (25°) in Korea. The bulk density in the groundwater areas was lower than that in other surveyed areas.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.5
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• pp.92-103
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• 2008

Development of new approaches to achieve naturally good ecological potential of forest road cut-slope by making the best use of advantages of gabion systems with vegetation base materials to prevent slope failure and erosion, in the area with highly erodible soil. As a result on the type analysis of gabion systems already installed in road cut-slopes, gabion systems were generally established to prevent slope failure. Existing gabion systems can be divided into monolithic and modular system and can be divided into ten subtypes according to the purpose of establishment and combination of other measures. As a result on the monitoring of erosion amount from forest road cut-slopes in the test applications, the order of erosion amount from largest to smallest is as follows : the curved road cut-slope site where normal gabion system was established ($7,911cm^3$); the control site ($7,632cm^3$); the straight road cut-slope site where normal gabion system was established ($7,301cm^3$); the curved road cut-slope site where the new gabion system was established ($5,684cm^3$); and the straight road cut-slope site where the new gabion system ($5,325cm^3$). Therefore, the result shows that the new gabion system is more effective than the normal gabion system to reduce erosion amount from forest ! road cut-slopes. During the study period, vegetation coverages of the straight and curved road cut-slope site where the new gabion system was established were about 45% and about 36%, so average vegetation coverage of the sites where the new gabion systems was established was higher than the sites where the normal gabion systems was established. Therefore, it was concluded that the new gabion system can be more effective for cut-slope revegetation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.69-79
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• 2005

This study was carried out to select proper species for early stage replantation in highway cut-slope area. In highway cut-slope area, sample plots of 106 were selected, and their vegetations and environmental factors were investigated. 1. We found total 172 species in the 106 cutting area of highway. The species of high frequency of highway cut-slope were found in the order of Lespedeza bicolor, Artemisia princeps var. orientalis, Festuca arundinacea, Erigeron annuus, Lespedeza cuneata, Lactuca indica var. laciniata, Eragrostis curvula, Dactylis glomerata, Oenothera lamarckiana, Wistaria floribunda, Humulus japonica, Commelina communis, Miscanthus sinensis, Pueraria thunbergiana, Pinus densiflora, etc. 2. The average vegetation coverage was over 90% in the study sites and the average coverage was 91.4% in the total cut-slope area. The species of high coverage of highway cut-slope area were found in the order of Festuca arundinacea, Eragrostis curvula, Lespedeza bicolor, Wistaria floribunda, Lespedeza cuneata, Dactylis glomerata, Artemisia princeps var. orientalis, Humulus japonica, Pueraria thunbergiana, Robinia pseudoacacia, Poa pratensis, Medicago sativa, Festuca ovina, Pinus densiflora, Parthenocissua tricuspidata, etc. 3. The total coverage in the foreign plants of Festuca arundinacea, Eragrostis curvula, Dactylis glomerata, Poa pratensis, Medicago sativa, Coreopsis drummondii and native plants of Lespedeza bicolor, Wistaria floribunda, Lespedeza cuneata, Amorpha fruticosa, Indigofera pseudotinctoria, Lespedeza cyrtobotrya were 57.52%. That is, the ecological succession of native herbs and parachute shrubs have delayed because the afforested plants occupy 57.52%. In future, the coverage of foreign herbs have to reduce, and the coverage of the native herbs and parachute shrubs must be increased. 4. The native seed of Artemisia sp., Miscanthus sinensis, Smilax china, Pueraria thunbergiana, Rubus crataegifolius, Rubus parvifolius, Pinus densiflora, Rhus chinensis, Albizzia julibrissin, Rhododendron mucronulatum, Clematis apiifolia, Zanthoxylum schinifolium, Prunus sargentii could be added in the seedling of the temperate south zone highway with the used seeds. The native seed of Artemisia sp., Miscanthus sinensis, Rubus crataegifolius, Rhododendron mucronulatum, Weigela subsessilis, Stephanandra incisa, Rhus chinensis, Pinus densiflora, Salix koreensis, Cocculus trilobus, Populus alba, Spiraea prunifolia for. simpliciflora, Clematis apiifolia, Lindera obtusiloba, Quercus serrata, etc., could be added in the seedling of the temperate middle zone highway with the used seeds. 5. We have some recommendation. The native plants have to growth in the highway cut-slope area instead of foreign plants to have good environmental ecology. The role of the foreign plants should be the plant for the initial several years in the highway cut-slope area. And, the native plants should growth in the next season. 6. We should protect shrubs and trees in the highway slope area because shrubs and trees can be more helpful in stabilizing of the slope area than herbs.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.162-172
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• 1990

Habit type classification based on the polyclimax and discontinuum concept applied to Mt. Kasan forest. The results obtained were summirized as follows. 1. PIDE/RHSC H.T. : Pizzas densiflora is a topographic climax which is distributed in a ridge and a upper slope. Rhododeudron schlippenbachii is well represented in the undergrowth (average coverage 21%). 2. CALA/CAAR H.T. : Carpinus laxiflora is distributed in a low slope and adjoined to Pinzrs densiflora of a upper slope and a ridge. Calamaglotis aruredinacea is well represented in the undergrowth (average coverage 10%). 3. QUMO/CAHU H.T. : Quercus mongolica is a topographic climax which is distributed in a upper slope and a midslope of the Kasan fort outside and ranged from 600m to 700m, Carex humilis is well represented in the undergrowth (average coverage 21%). 4. QUMO/CAAR H.T. : Qreercus moragolica is distributed in the basin of Mt. Kasan fort inside and ranged from 700m to 870m, Cdlamagrotis arundinacea is abundant in the undergrowth(average coverage 43%). 5. FRRH/IMTE H.T. : Fraxinus rhynchophilla is distributed in a valley. Impatiens textori is well represented in the undergrowth(average coveraged 10%). 6. COCO/VISA H.T. : Cornus controversa is distributed in a valley and aranged from 780m to 830m Viburunum sargentii is well represented in the undergrowth(average coverage 12%).

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.6
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• pp.172-182
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• 2003

In this study, the back analysis was performed by means of stereo-net, plane failure and block failure method to collapsed fields among the rock slopes designed by standardized criterion, and the internal frictions from the back analysis were compared with those used to reinforcement design. It was concluded that in the result of the analysis by means of stereo net, plain failure and block failure methods, the internal frictions used to re-design of collapsed slope underestimated 10$^{\circ}$, 5$^{\circ}$ and 10$^{\circ}$ in average. At present, the internal friction on the design is used the experience value according to the state of weathering, but internal friction angle by the back analysis on collapsed slope with various methods were more reliable values than those from the present method. And it was concluded that re-design was made extravagantly because the internal friction used to re-design for reinforcement of the collapsed slope was less than back analysis.