• 한국지반공학회논문집
• /
• 제35권5호
• /
• pp.21-30
• /
• 2019

얕은 터널에 대한 연구는 종방향 하중전이와 수평지반에 대한 연구가 주를 이루었으며 사면 하부에 위치한 얕은 터널 주변지반의 거동연구는 미흡한 실정이다. 따라서 본 연구에서는 사면 하부에 위치한 터널의 종방향 굴진에 따른 터널 주변지반의 거동을 규명하기 위해 변위제어방식으로 모형시험을 실시하였다. 모형터널은 폭 320mm, 높이 210mm, 길이 55mm 규격의 강성이 큰 알루미늄 강체로 제작하였고, 모형지반은 3가지 규격의 탄소봉을 혼합하여 균질한 모형지반을 조성하였다. 모형시험은 사면 경사와 토피고를 변수로 측벽변형을 발생시키는 변위제어방식으로 실시하였으며, 터널 벽체의 하중변화, 터널 주변지반의 하중전이와 지표침하 변화를 측정하고 분석하였다. 지표침하의 변화는 경사가 증가할수록 수평지반보다 20~39%의 증가가 나타났다. 터널 천단부 및 측벽부의 하중 변화는 사면 경사가 증가할수록 천단부는 최대 20%가 증가하고, 측벽부는 사면 경사의 영향으로 하중비가 감소하는 것을 확인하였다. 연직하중은 토피고가 1.0D 이하에서는 최대 128%의 하중증가가 나타났지만, 토피고가 1.5D 이상에서는 수평지반과 큰 차이가 나타나지 않았다. 이것으로 사면 경사는 토피고 1.0D에서 가장 큰 영향이 나타나는 것을 확인하였다.

• Journal of the Korean Statistical Society
• /
• 제27권4호
• /
• pp.471-483
• /
• 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.

• 한국세라믹학회지
• /
• 제33권12호
• /
• pp.1373-1379
• /
• 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.

• 아동학회지
• /
• 제29권1호
• /
• pp.15-32
• /
• 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.

• 산업기술연구
• /
• 제25권B호
• /
• pp.47-54
• /
• 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
• /
• 한국지형공간정보학회 2005년도 아시아 태평양 국제 GSIS 학술발표회
• /
• pp.61-72
• /
• 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.

• 대한전자공학회논문지
• /
• 제25권7호
• /
• pp.819-825
• /
• 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
• /
• 제15권1호
• /
• pp.669-676
• /
• 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.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2002년도 가을 학술발표회 논문집
• /
• pp.147-179
• /
• 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.

• 디지털콘텐츠학회 논문지
• /
• 제17권5호
• /
• pp.441-448
• /
• 2016

본 논문에서는 문자열과 배경이 혼합된 장면에서 영상을 분할하여 기울기를 추출하고 보정하는 방법을 제안한다. 제안된 방법은 모폴로지를 이용하여 전처리를 하고 캐니 연산자를 이용하여 경계선을 검출한다. 그리고 경계선이 검출된 영상을 분할하여 경계선이 포함되어 있지 않는 영역은 배제하고 경계선이 포함되어 있는 영역만을 이용하여 여러 방향의 기울기에 따른 투영 히스토그램을 생성한다. 이를 이용하여 각 영역의 최대 경계선 집중도를 갖는 기울기를 구하고 장면의 기울기를 보정한다. 문자열과 배경이 혼합된 장면의 기울기 검출에서 제안된 방법은 경계선이 없는 무의미한 부분을 배제하기 때문에 기존의 방법보다 0.7% 더 좋은 결과를 얻을 수 있었다.