• The Journal of Engineering Geology
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• v.33 no.2
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• pp.229-240
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• 2023

Instruments are installed in soft ground improvement projects to manage economic and safe construction. When analyzing data, the amount of settlement data over time can be used to understand the overall ground settlement behavior, but it is difficult to analyze the interrelatedness between measurement points. Therefore, to analyze the relative compressive settlement behavior between measurement points, the settlement amount and velocity were processed and defined as the mean settlement difference index (AS_i,j) and the slope difference index (SDI_i,j). Plotted in the mean settlement difference index - slope difference index (AS_i,j-SDI_i,j) coordinate system. As a result of the analysis of the relative compaction subsidence behavior between the measuring points, the relationship between the measuring points in the average subsidence difference index - slope difference index coordinate system moved to area 1 as the compaction was completed. By continuously plotting the movement path of the observation point in the corresponding coordinate system, the relative settlement behavior between the measurement points was analyzed, and it was possible to check whether the settlement behavior of the two measurement points was stable or unstable depending on the direction of the path.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.764-771
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• 2010

The stability analysis method of an unsaturated slope considering the suction stress was performed on the infinite sand slope. During drying and wetting processes, the Soil-Water Characteristics Curve (SWCC) of the sand with the relative density of 75% was measured using the automated SWCC apparatus. Also, the Suction Stress Characteristics Curve (SSCC) was estimated. Based on these results, the stability analysis of an unsaturated infinite slope was carried out considering the slope angle, the weathering zone and the relative change in friction angle as a soil depth. According to the result of slope stability analysis, the safety factors of slope were less than 1 when the slope angles were more than $50^{\circ}$. The safety factors of slope tend to increase with increasing the depth from the ground surface. Especially, the safety factors have a tendency to increase and decrease above near the ground water level due to the suction stress. The maximum safety factor of slope in this analysis was occurred at the Air Entry Value (AEV) of drying process. The influence range of suction stress above the ground water level can be found out and can be defined as the funicular zone which means the metric suction range from the air entry point to the point of residual volumetric water content.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.425-435
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• 2020

This study aims to investigate the impact of the physical structure, such as altitude, slope gradient, slope direction, and topographical structure, and the vegetation pattern, such as existing vegetation, diameter of breast height (DBH), and crown density, on climate. The analysis results showed the significant difference in relative humidity, wind speed, and solar radiation at varying altitudes, the significant difference in all climate factors except for the wind speed at varying slope gradient, and significant difference in temperature and relative humanity at varying slope direction. The topographic structures were divided into valleys, slopes, and ridges. They were found to differ in relative humidity. However, the differences between constant trends and types were found to be insignificant concerning temperature, wind speed, and solar radiation. Significant differences in temperature, relative humidity, and wind speed were recorded with changing existing vegetation. The DBH showed a significant difference in temperature, wind speed, and solar radiation. The crown density showed a significant difference in temperature and solar radiation. The result of the relationship analysis for the analysis of the effect of vegetation pattern and physical structure on the meteorological environment showed that temperature was affected by slope gradient, slope direction, DBH, and crown density. The relative humidity was correlated with the altitude, slope gradient, slope direction, and topological structure in physical structure and the existing vegetation and crow density in vegetation pattern. The wind speed was correlated with the altitude, existing vegetation, and DHB, and the solar radiation was correlated with the slope gradient, DHG, and crown density. The crown density was the most overall significant factor in temperature, relative humidity, and solar radiation, followed by the slope gradient. DBH was also found to be highly correlated with temperature and solar radiation and significantly correlated with wind speed, but there was no statistically significant correlation with relative humidity.

• Korean Journal of Environmental Biology
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• v.24 no.4
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• pp.337-358
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• 2006

The field survey was conducted weekly from April to October in 2004 and 2005 on the sites along the 5.16 road. Sampling sites were made every 100 m height starting from 250 m altitude of both sides of Mt. Halla along 5.16 Road, which crosses the mountain from North to South. Totally 31,698 individuals of 76 species belonged to 25 families were collected. It was July that showed the largest number of species, as 48 species in the northern sloper 42 in the southern slope, and 22 at the highest site (at an altitude of 750 m), while it was April that showed the smallest as 17 species, 15 and 5, respectively. As for monthly fluctuation, the northern slope and the highest site reached their top in August, whereas it was June in the southern slope. In the analyses of similarity (chord distance) of any pair of temporal communities, the closest pair was between June and July in the northern slope area, between July and August in the southern slope and between July and September at the highest site, respectively.

• The Korean Journal of Ecology
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• v.7 no.3
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• pp.119-131
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• 1983

The cluster analysis on the distribution of epiphytic lichens on the north, south, east and west slope of Mt. Hanra was carried out by three methods, sum of square algorithm (SSA), prinicipal component analysis (PCA) and multidimensional scaling method(MDS). Analysis of concentration (AOC) was used for the comparison between the lichen communities of north and south slope. The lichen species was identified 35 species by Hale and Culberson technique. The classification of sites by SSA method was divided into two areas in four slopes, and that of species by SSA, PCA and MDS methods was classified into three clusters in east slope, four clusters in south and west slope, and there clusters in north slope. The comparison between north and south slope of the distribution of lichens indicates that loight elevation of north slope (NH; 1600m~1900m) was similar to that of relative low elevation of south slope (SL; 1000m~1300m). The genus lichen, Anaptychia, Parmelia, Lobaria and peltigera was found as the dominant genus in both slopes.

• Tunnel and Underground Space
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• v.6 no.2
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• pp.166-174
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• 1996

Stability of rock slope is greatly affected by the geometry and strength of discontinuities developed in the rock mass. In this study an analytical method which is capable of analyzing the effect of relative orientation between the discontinuities and the slope face on the safety of slope by assessing their vector components was used to evaluate the stability and the maximum cut-angle for the proposed slope design. The results of computerized vector analysis revealed that slope area under investigation might be divided into 3 sections of different face directions. The safety factors for benches in each 3 sections were calculated using the limit-equilibrium theory. Then, by utilizing the concept of probabilistic risk analysis, the susceptibility of entire slope failure was estimated. Based on the distribution of safety factor in each bench, the maximum cut angle of each section could be selected differently ot achieve the permanent stability of the entire slope.

• Journal of Korean Society of Rural Planning
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• v.23 no.2
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• pp.87-96
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• 2017

This study is a basic research with the aim of developing the method of judging the leakage zone by grasping the habitat characteristic of agricultural reservoir slope in inhabiting characteristics appear differently according to natural inhabiting environment. To this end, this study is intending to investigate slope vegetation using a quadrat technique at Sinheung reservoir located at Gwangsi-myeon, Yesan-gun, Chungnam, and to perform the analysis of importance value using relative frequency and relative coverage, etc. Also, this study intended to present the necessity of having to consider the eco-system of the relevant region in time of a reservoir slope afforestation for the time to come by suggesting that the reservoir slope vegetation after a stable period becomes similar to the regional vegetation by comparing this study result with the existing research which carried out the analysis of importance value of forest vegetation for Yesan Region. The reservoir slope vegetation is similar to the indicator species which appear in the regional forest vegetation, so there was a need to select afforestation species in the light of this in time of slope afforestation. As a result of the analysis of the importance value, this study grasped that there was an emergence characteristic similar to the vegetation at a birthplace of a forest fires because growth and development of forest trees, and perennial plants were restricted by annually implemented brush-cutting work, etc.; however, indigo plant and bush clover, etc. were found to show the characteristic differing from this. Consequently, this study was able to confirm that there is the necessity of having to create the Importance Value Table suited for reservoir slopes by region through a lot more data construction in the near future.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.615-620
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• 2002

Probability distribution of the sea surface slope is estimated using sun glitter images derived from visible radiometer on Geostationary Meteorological Satellite (GMS) and surface vector winds observed by spaceborne scatterometers. The brightness of the visible images is converted to the probability of wave surfaces which reflect the sunlight toward GMS in grids of 0.25 deg $\times$ 0.25 deg. Slope and azimuth angle required for the reflection of the sun's ray toward GMS are calculated for each grid from the geometry of GMS observation and location of the sun. The GMS images are then collocated with surface wind data observed by three scatterometers. Using the collocated data set of about 30 million points obtained in a period of 4 years from 1995 to 1999, probability distribution function of the surface slope is estimated as a function of wind speed and azimuth angle relative to the wind direction. Results are compared with those of Cox and Munk (1954a, b). Surface slope estimated by the present method shows narrower distribution and much less directivity relative to the wind direction than that reported by Cox and Munk. It is expected that their data were obtained under conditions of growing wind waves. In general, wind waves are not always developing, and slope distribution might differ from the results of Cox and Munk. Most of our data are obtained in the subtropical seas under clear-sky conditions. This difference of the conditions may be the reason for the difference of slope distribution.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.867-872
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• 2009

Peak expiratory flow rate(PEF) is one of the most important diagnostic parameters in spirometry. PEF occurs in a very short duration during the forced expiratory maneuver, which could lead to measurement error due to non-ideal dynamic characteristic of the transducer. In such case the initial slope of the flow rate signal determines the accuracy of the measured PEF. The present study considered this initial slope as a parameter to compensate PEF. The 26 standard flow rate signals recommended by the American Thoracic Society(ATS) were flown through the air flow transducer followed by simultaneous measurements of PEF and maximum transducer output$(N_{PEF})$. $N_{PEF}$-PEF satisfied a quadratic equation in general, however, two signals (ATS #2 and #26) having large initial slopes deviated from the fitting equation to a significant degree. The relative error was found to be in a linear relationship with the initial slope, thus, $N_{PEF}$ was appropriately compensated to provide accurate PEF with mean relative error less than only 1%. The 99% confidence interval of the mean relative error was less than a half of the error limit of 5% recommended by ATS. Therefore, PEF can be very accurately determined by compensating the transducer output based on the initial slope, which should be a useful technique for air flow transducer calibration.

• Journal of Korea Water Resources Association
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• v.41 no.5
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• pp.503-515
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• 2008

In this study we calculate discharge by slope-area method using continuously observed water level data and analyse the results. This study is performed in the Dalcheon river reach of 960 m length including riffles and a pool, which is located downstream of the Goesan Dam. Three values of roughness coefficient are applied to discharge calculation, which are established using bed material size analysis. Another roughness coefficient value obtained from the river improvement plan is also used. Calculated discharges by slope-area method are compared with dam discharges. Relative difference from dam discharges appears to be largely affected by roughness values and a value of 0.042 or more seems most suitable for the entire study reach. Smaller roughness value is suitable to the reach which has gentler water surface slope than mean channel slope of the entire study reach, while a larger value to steeper reach. In case roughness value is set considering overall slope of the channel, it is desirable to select the entire calculation reach including both gentler and steeper sub-reaches. Since relative difference becomes nearly constant at over 500 cms, in case that verification of applied roughness is conducted with other directly measured discharge, accuracy of measurement by slope-area method for larger discharge may be improved.