• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.1
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• pp.49-56
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• 1998

Ths study was peformed to evaluate the degree of degradation and safety of a small agricultural reservoir, Kosam Reservoir, in Kyungki Province. Evaluation was done by the program developed by the authors. Results of the study are as follows: 1) Although many burrows were found in downstream side of embankment and cracks were found in wall joining spillway, it appeared that degree of degradation of embankment was in good conditions. 2) Compressive strengths of concrete of crest, side channel, chute floor of spillway were in poor condition. But it appeared that overall degree of degradation of structures was in medium condition based on the criteria of the evaluation system 3) From the analysis of slope stability, safety factor of downstream slope was over 3.3 for the worst condition, such as flood and high water level and that of upstream slope was also over 3.6 for rapid drawdown. In case of earthquake, safety factors were over 2.5 for all conditions. Therefore embankment slopes of Kosam Reservoir were very stable for normal and earthquake condition. 4) As upon assumed failure of embankment of Kosam Reservoir, degree of damage was estimated to be very serious because of many loss of life and properties in the downstream area. 5) Overall grade of safety of Kosam Reservoir was in good condition. Therefore safety was considered to be "No problems" at the present time but further degradation may be proceeded partly and continuously as time goes by.e goes by.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.51-60
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• 2006

At new constructing national road, a cutting slope was surveyed and gotten face mapping for three months. The slope is composed of gray phyllite and coaly slate which is the Chang-ri Formation, Okcheon system. The slope angle is 40 degree and the direction is NNE. The attitude of schistosity is $260^{\circ}/45^{\circ}$. So the slope direction is nearly parallel to the schistosity. This is the reason that the slope is very unstable. On the other hand, the very unstable slope is caused by the direction of the schistosity and the slope. First month the coaly slate was slided through the schistosity plane about 10cm. However, three months late the displacement was 2m maximum.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.1
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• pp.13-30
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• 1993

The purpose of this study was to present data to the landscape planning and design through analyzing correlation between visual preference of users and nonusers and the landscape of hole in golf couses. Stimulus objects were selected from the 18 holes in Tae-gu Country Club. Preference value was judged through photo simulation by 35 subjects photographed at Tee and Interpoint (IPI, IP2), and classified into three landscape types and nine landscape components from photo analysis by researcher. For test of difference between groups toward each stimulus, t-test was used, and Duncantest, Correlation analysis for finding out correlation between preference degree and the landscape of each hole. The results of this study were as follows: As a result of analysis of preference value between groups for each hole, it has been shown that there was scarcely difference with each other. Form the relation between preference degree and spacial structure of hole, the holes making up a superior preference group have been shown that the greater part of the holes had a downward slope or a gentle slope mostly and then a visible ratio of fairway was high, and had diversified scenery by a lotus pond, a solitary planting tree, the roll of a fairway, facilities for convenience, etc. The holes making up a low-ranking preference group have been shown that the greater part of the holes had upward slope or a similar slope to it and had characteries of the bad condition of lawn, the nearby factories and odors, the monotonous scenery of a fairway, an unreasonable mixing of holes, etc. From the relation between preference degree and landscape components forming hole, it has been shown that the preference degree between users and nonusers had positive correlation to the occupied ratio of space of landscape components at Tee and Approach. At Tee, it has been shown that the preference degree of two groups were related with a lawn surface of fairway negatively, a lotus pond, a sky positively, and the preference degree of nonusers was related with iron-top for electric transmission positively. At Approach, it has been shown that the preference degree of two groups were related with iron-top for electric transmission negatively, and the preference degree of nonusers was related with a building positively. From the relation between preference degree group to each hole and the occupied ratio of space of landscape types, it has been shown that the constituent ratio of a high-ranking group was 1:2.4:2.2 and a low-ranking group was 1:4.1:5.1 among vertical type, horizontal type and background at Tee, but the constituent ratio of space of a high-ranking group was similar to a low-ranking group at Approach.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.83-93
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• 2012

This study is to perform the effect of urbanization in urban and suburban districts, and to identify regional characters of climate according to the analysis of slope at rise, and descent of temperature and globe temperature, correlation between seasonal temperature analysis, and calculation of degree hour. According to this study, the result is summarized as follows. (1) The average temperature, rated from high to low, consists of residential area, Daegu weather station, intracity, green belt, water-front green belt, and suburban. (2) At the rise and descent of temperature, the result of the slope change of in each point may be one of the useful indexes to be able to perform the regional unique thermal characteristic, including the seasonal urbanization. (3) Although there is a difference between the surface of the earth and ambient environment. The result of the correlation of temperature between summer and winter is that temperature slope in urban districts was higher than in suburban districts, and the difference of slope was unvaried among the four observations in the same city region. (4) To show objectively, regional thermal characteristics in urban and suburban districts, the exponentiation of winter degree hour and summer degree hours were checked. The result of the exponentiation is that the more artificial a region, the lower index.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.41-52
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• 2013

This study was carried out in order to analyze the succession characteristics of the slope of expressways and the results of analysis by collecting and analyzing various literatures and data from 2011 to 2012 and surveying 75 expressway slope, as follows : The construction methods applied to planting the slope of an expressway can be classified into 4 types including 3 Climber planting methods, 8 Vegetation thick-layer spray work methods, 4 Seed spray work methods, and 4 Stabilization work methods. The factors which affect the cover degree of the slope of an expressway were found to be development years, gradient, length, and azimuth. Like surrounding forest areas, the expressway slope was analyzed to begin the plant succession 20, 30, and 40 years after development, and plant succession was developed in diversity in a mixed stand forest according to surrounding forest floors. Species diversity, maximum species diversity, and the evenness of slope facing north were analyzed to be high comparing to those facing east, west, and south according to azimuth of slope. Species diversity, maximum species diversity, evenness of slope, and the plant succession of surroundings were analyzed to be high when the gradient of the slope was less than $40^{\circ}$. The dominant species which success on the slope of an expressway and its surrounding forest area included Miscanthus sinensis var. purpurascens, Zoysia japonica, Pinus thunbergii Parl, Rubus crataegifolius, Lespedeza cyrtobotrya, Amorpha fruticosa, Artemisia princeps var. orientalis, and Oenothera biennis.

• Journal of Bio-Environment Control
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• v.7 no.4
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• pp.324-329
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• 1998

Effect of roof slope on the transmissivities of direct and diffuse solar radiation using a computer simulation model developed by Kim and Lee(1997) was analyzed for 10-span glasshouse located in Seoul(37$^{\circ}$34' N), Chonju(35$^{\circ}$49' N) and Cheju(33$^{\circ}$31' N). Transmissivities of diffuse solar radiation in glasshouse with roof slopes of 15, 20, 24.6, 30 and 35 degree were calculated as 61.3, 61.6, 61.7, 56.8 and 58.6%, respectively. Transmissivities of direct solar radiation(TDSR) during the period except summer season were highly affected by the roof slope. During the winter season, TDSR in glasshouse with roof slopes of 30 and 35 degree were higher than those with other roof slopes. Also, during the period except winter season, TDSR in glasshouse with roof slope of 20 degree were higher than those with other roof slopes. Difference in TDSR with latitude was significant during the period from October to February. At this period TDSR were highly appeared at lower latitude. Effect of roof slope on TDSR in S-N greenhouse was smaller than those in E-W greenhouse. It is considered that direct solar radiation highly transmitted in the glasshouse with roof slope of 20 degree.

• Tunnel and Underground Space
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• v.5 no.4
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• pp.308-317
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• 1995

The stability study on the rock slope where have produced failures in Boryung dam site was evaluated using the streonet analysis techniques. SMR(Slope Mass Rating) approach which is suitable for preliminary assessment of slope stability in rock was also carried out for rating rock mass. The 3-4 major discontinuity sets are distributed and all type of failure(plane, wedge and toppling failure) are presented in this slope face. The dip of slope must be lowered to friction angle(26degree), otherwise the possibility of plane and toppling faiue will always exist in this slope.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.45-54
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• 2008

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in gneiss area, a prediction technique was developed by the use of a decision tree model, which is one of the statistical analysis methods. The slope hazards data of Seoul and Kyonggi Province, which were induced by heavy rainfall in 1998, were 104 sections in gneiss area. The number of data applied in developing prediction model was 61 sections except a vacant value. Among these data, the number of data occurred slope hazards was 34 sections and the number of data non-occurred slope hazards was 27 sections. The statistical analyses using the decision tree model were applied to chi-square statistics, gini index and entrophy index. As the results of analyses, a slope angle, a degree of saturation and an elevation were selected as the classification standard. The prediction model of decision tree using entrophy index is most likely accurate. The classification standard of the selected prediction model is composed of the slope angle, the degree of saturation and the elevation from the first choice stage. The classification standard values of the slope angle, the degree of saturation and elevation are $17.9^{\circ}$, 52.1% and 320 m, respectively.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.4
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• pp.31-43
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• 2022

In this study, we estimated the monthly FDSI (Flash Drought Stress Index) for assessing flash drought on South Korea using AMSR2(Advanced Microwave Scanning Radiometer 2) satellite-based soil moisture footprints. We collected the AMSR2 soil moisture and climate-land surface data from April to November 2018 for analyzing the monthly FDSI values. We confirmed that the FDSI values were high at the regions with the high temperature/evapotranspiration while the precipitation is relatively low. Especially, the regions which satisfied an onset of flash drought (FDSI≧0.71) were increased from June. Then, the most of regions suffered by flash drought during the periods (July to August) with the high temperature and evapotranspiration. Additionally, the impacts of landuse and slope degree were evaluated on the monthly FDSI changes. The forest regions that have the steep slope degree showed the relatively higher FDSI values than the others. Thus, our results indicated that the the slope degree has the relatively higher impact on the onset and increasing of flash drought compared to the others.

• Communications for Statistical Applications and Methods
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• v.3 no.1
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• pp.51-59
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• 1996

A measure that quantifies the amount of slope retatability for the second degree Scheffe polynomial model for mixture experiments is proposed and used to compare the several mixture designs which met the symmetric momemts conditions in this article.