• Journal of the Korean Geotechnical Society
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• v.35 no.5
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• pp.21-30
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• 2019

While the study of the shallow tunnel has been mainly on the longitudinal load transfer and horizontal surface conditions, the study of the ground behavior of shallow tunnel under the slope is not sufficient. Therefore, in this study on the ground behavior around a tunnel due to the sidewall deformation of shallow tunnel under the slope that is excavated in longitudinal direction, a scale-down model test has been performed. The model tunnel has the dimension of 320 mm wide, 210 mm high and 55 mm long with enough material strength in aluminum and the model ground has the uniform ground conditions by 3 types of carbon rods. The model test has been performed with the variables of slopes and the cover depths by controlling the tunnel sidewall deformation, and the change of sidewall-load, load transfer, ground subsidence was monitored and analyzed. According to the increase of the slope, the maximum ground subsidence increased by 20~39% compared to the horizontal surface. The load ratio increased by maximum 20% in the tunnel crown and decreased in sidewall according to the surface slope. The load transfer shows maximum 128% of increase at the cover depth of 1.0D, while at the 1.5D cover depth it shows non-critical difference from horizontal surface. The slope has major effects on load transfer at the cover depth of 1.0D.

• Journal of the Korean Statistical Society
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• v.27 no.4
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• pp.471-483
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• 1998

The influence of observations on the misclassification probability in multiple discriminant analysis under the equal covariance assumption is investigated by the local influence method. Under an appropriate perturbation we can get information about influential observations and outliers by studying the curvatures and the associated direction vectors of the perturbation-formed surface of the misclassification probability. We show that the influence function method gives essentially the same information as the direction vector of the maximum slope. An illustrative example is given for the effectiveness of the local influence method.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1373-1379
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• 1996

Change of sintering shrinkage in alumina-based multilayer ceramics was observed in various lamination condi-tions and binder burnout (BBO) temperatures. It was found that the linear shrinkages in X and Y directions were nearly the same with the BBO temperatures but a large shrinkage difference in Z direction was observed. However this phenomenon was diminished when BBO temperature was increased. A linear relationship between the laminated density and the sintering shrinkage was found and the slope was independant on the BBO temperature but dependant on the shrinkage direction.

• Korean Journal of Child Studies
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• v.29 no.1
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• pp.15-32
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• 2008

The logical and mathematical thinking of 1- to 3-year-olds was studied by age groups at 6 month intervals; logical-mathematical thinking was examined by the two physical knowledge activities of cylinder rolling and making a slope. Results showed that in their early 1st year infants failed in both tasks. Infants in their late 2nd year showed understanding of 'rolling things' and 'non-rolling things' by comparing cylinders and cubes in the cylinder rolling activity and they showed 'spatial inference' by adjusting the position and direction of the cylinder so that the cylinder could roll properly and by adjusting the board on a block in the slope making activity. Three-year-old children rolled a cylinder and made a slope without difficulty.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.47-54
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• 2005

The goal of this study is to generate a landslide potential map using GIS(Geographic Information System) based method. A simple and efficient algorithm is proposed to generate a landslide potentialities map from DEM(Digital Elevation Model) and existing maps. The categories of controlling factors for landslides, aspect of slope, soil, vegetation are defined. The weight value for landslide potentialities is calculated from AHP(Analytic Hierarchy Process) method. Slope and Slope-direction is extracted from DEM, and soil information is extracted from digital soil map. Also, vegetation information is extracted from digital vegetation map. Finally, as overlaying, landslide potentialities map is made out, and it is compared with landslide place.

• 한국지형공간정보학회:학술대회논문집
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• 2005.08a
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• pp.61-72
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• 2005

The landslide risk assessment process consists of hazard risk assessment and vulnerability analysis. landslide hazard risk is location dependent. Therefore, maps and spatial technologies such as GIS are very important components of the risk assessment process. This paper discusses the advantages of using GIS technology in the risk assessment process and illustrates the benefits through case studies of live projects undertaken. The goal of this study is to generate a map of landslide vulnerability map by analysis of static natural factors with GIS. A simple and efficient algorithm is proposed to generate a landslide potentialities map from DEM and existing maps. The categories of controlling factors for landslides, aspect of slope, soil, vegetation are defined. The weight values for landslide potentialities are calculated from AHP method. Slope and slope-direction are extracted from DEM, and soil informations are extracted from digital soil map. Also, vegetation informations are extracted from digital vegetation map. Finally, as overlaying, landslide potentialities map is made out, and it is verified with landslide place.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.7
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• pp.819-825
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• 1988

An 1-bit DPCM image coding method is presented. Our method is specially designed to reduce the slope overload which seems to be the major performance degradation factor in 1-bit DPCM. In the present algorithm, based on the classification of neighborhoods by its flatness, slope strength and direction, predictor and quantizer operate adaptively through switching action. Compared with some other methods by computer simulation, proposed method shows improved performance in image quality as well as in signal to noise ratio. This gain mainly comes from the reduced slope overload and seems large to compensate the increased complexity in prediction. As a post processing, Lee filter is used to reduce the granular noise subjectively annoying in flat region.

• Geomechanics and Engineering
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• v.15 no.1
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• pp.669-676
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• 2018

The "pseudo-wedge" failure is a name for a complex instability occurring at the Sarcheshmeh open-pit mine (Iran). The pseudo-wedge failure contains both the rock bridge failure and sliding along pre-existing discontinuities. In this paper, a cross section of the failure area was first modeled using a bonded-particle method. The results indicated development of tensile cracks at the slope toe which explains the freedom of pseudo-wedge blocks to slide. Then, a three-dimensional discrete element method was used to perform a block analysis of the instability. The technique of shear strength reduction was used to calculate the factor of safety. Finally, the influence of geometrical characteristics of the mine wall on the pseudo-wedge failure was investigated. The safety factor significantly increases as the dip and dip direction of the wall decrease, and reaches an acceptable value with a 10-degree decrease of them.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.147-179
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• 2002

The important role of observational method in geotechnical engineering are emphasized together with the direction of future development, concerning successful application of the technique on the site investigation, design and feed back at various construction stages. Case histories on the application of feed back are introduced in order to achieve the most economical and reliable construction for tunnel, rock slope and deep excavations through feed back system at design and construction stages. Also the limitations and advantages of the observational method and the role of feed back system are discussed for construction of tunnel, rock slope and deep excavation in hard ground such as layered ground conditions including weathered, soft and hard rocks.

• Journal of Digital Contents Society
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• v.17 no.5
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• pp.441-448
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• 2016

In this paper, we propose a method that segments the image, extracts its slope and compensate it in the image that text and background are mixed. The proposed method uses morphology based preprocessing and extracts the edges using canny operator. And after segmenting the image which the edges are extracted, it excludes the areas which the edges are included, only uses the area which the edges are included and creates the projection histograms according to their various direction slopes. Using them, it takes a slope having the greatest edge concentrativeness of each area and compensates the slope of the scene. On extracting the slope of the mixed scene of the text and background, the method can get better results as 0.7% than the existing methods as it excludes the useless areas that the edges do not exist.