• 지구물리
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• 제8권3호
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• pp.123-130
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• 2005

It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure zone resulted from weathering effect and other factors. The FBG sensor system is used to estimate the correlations between the temperature and the slope in Kimhae, and to find a failure zone in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the correlation. For instance, the zone of high temperature fluctuation can be regarded as one of the possible sliding zone due to the weathering effect while the constant temperature depth of the ground, if exists would not be relatively affected by the weathering process.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.643-650
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• 2002

It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure zone resulted from weathering effect and other factors. The FBG sensor system is used to estimate the correlations between the temperature and the slope in Yunhwajae, and to find a failure zone in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the correlation. The zone of high temperature fluctuation can be regarded as one of the possible sliding zone due to the weathering effect while the constant temperature depth of the ground, if exists, would not be relatively affected by the weathering process.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.133-136
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• 2004

In-situ collection experiments were performed to analyze inflowing sedilnents behavior as a basic study of topographical change in Nakdong River Estuary. Sediment rate and bed load flux ranged from 0.0004 to $0.472\;g/cm^2/day\;and\;0.0005\~1.7579\;g/cm^2/day$, respectively. The settling velocity of suspended particulate matter was estimated in tire range of $0.339\~1.010\;cm/sec$, The grain size analysis shows that surface sediments in backside of sandbar and bed load in front of dike have a similar grain size distribution. It is considered that the source of surface sediments in backside of sandbar were flowed in from Nakdong River. In order to verify the characteristics of inflowing sediments behavior, detailed surveys around Nakdong River Estuary need to be carried out, continuously.

• Earthquakes and Structures
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• 제11권3호
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• pp.407-420
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• 2016

The aim of this study is to investigate the effect of vertical ground motion (VGM) on seismic behavior of reinforced concrete (RC) regular frame with construction joints, and determine more proper modeling method for cast-in-situ RC frame. The four-story RC frames in the regions of 7, 8 and 9 earthquake intensity were analyzed with nonlinear dynamic time-history method. Two different methods of ground motion input, horizontal ground motion (HGM) input only, VGM and HGM input simultaneously were performed. Seismic responses in terms of the maximum vertex displacement, the maximum inter-story drift distribution and the plastic hinge distribution were analyzed. The results show that VGM might increase or decrease the horizontal maximum vertex displacement depending on the value of axial load ratio of column. And it will increase the maximum inter-story drift and change its distribution. Finally, proper modeling method is proposed according to the distribution of plastic hinges, which is in well agreement with the actual earthquake damage.

• 한국세라믹학회지
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• 제31권12호
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• pp.1449-1458
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• 1994

A new analytical model which can discribe the relationship between the bridging stress and the crack opening displacement was proposed to investigate the microstructural effect on the R-curve behavior in a polycrystalline alumina. The crack opening displacement according to the distance behind the stationary crack tip was measured using in-situ fracture technique in an SEM, and then used for a fitting procedure to obtain the distribution of bridging stress. The current model and an empirical power law relation were introduced into the fitting procedure. The results indicated that the bridging stress function and R-curve computed by the current model were consistent with those computed by the power law relation. The microstructural factor, e.g., the distribution of grain size, was also found to be closely related to the bridging stress. Thus, this model explained well the interaction effect between the distribution of bridging stress and the local-fracture-controlling microstructure, providing important information for the systematic interpretation of microfracture mechanism including R-curve behavior of a monolithic alumina.

• 한국염색가공학회지
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• 제15권5호
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• pp.327-332
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• 2003

In this study, the polyurethane microcapsules for non-aqueous dyeing containing iron oxide and disperse dyes were prepared by in-situ polymerization method using hexamethylene diisocyanate(HDI) with ethylene glycol(EG). And the size, shape, and particle size distribution of microcapsules prepared were investigated. The size and shape of microcapsule were observed by optical microscope and scanning elecron microscope. The particle size distribution was analyzed by particle size analyzer. The microcapsule size and its distribution were largely effected by the existance of surface active agent in the system. When a surfactant did not exist in the system, the size distribution of microcapsules prepared was much uneven. By adding a surfactant, this phenomenon was disappeared. And the size of microcapsule was also effeced by the hydrophobicity of core material(disperse dye). It was considered due to the difference of dispersity of core materials. And the size of microcapsule prepared was inversely proportional to the stirring speed.

• 한국지반공학회논문집
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• 제25권2호
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• pp.17-24
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• 2009

일반적으로 점토의 비 배수전단강도 산정은 실내실험을 통해 구하지만 초연약점토의 경우 재료의 특성 상 실내실험이 어렵고, 현장실험 또한 여러 제약조건들을 감수해야 한다. 따라서 본 논문에서는 실내에서 수행한 물성실험 및 슬럼프실험과 실내 베인 전단실험의 결과를 회귀분석을 통해 슬럼프 값과 비 배수전단강도 사이의 상관 관계식을 도출하였다. 도출된 상관 관계식의 신뢰성 확보를 위하여 t-분포를 이용한 통계분석을 실시하였고 현장의 데이터와 비교 분석하여 관계식의 적용성 및 신뢰성을 확보하였다.

• 지구물리와물리탐사
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• 제7권1호
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• pp.56-61
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• 2004

In order to image the distribution of permeability in granitic rocks, we carried out two-dimensional (2D) resistivity profiling, together with in-situ permeability tests, electrical logging of boreholes, and resistivity measurements of rock core samples in a laboratory. Based on the electrical logging and in-situ permeability data from boreholes, we obtained empirical equations which relate resistivity and permeability of the granitic rocks in the area studied. We then applied the empirical equation to a 2D resistivity section, to produce a 2D permeability section of the granitic rocks. In this paper, we present details of the field data and of the procedure for conversion from the resistivity section to a permeability section. The observed relationship between resistivity and permeability of the rocks is also discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 말뚝기초 학술발표회
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• pp.85-106
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• 2000

The load distribution and deformation of drilled shafts subjected to axial loads were evaluated by a load transfer approach. The emphasis was on quantifying the load transfer mechanism at the interface between the shafts and surrounding highly weathered rocks based on a numerical analysis and small-scale tension load tests performed on nine instrumented piles. An analytical method that takes into account the soil coupling effect was developed using a modified Mindlin's point load solution. Based on the analysis, a single-modified hyperbolic model is proposed for the shear transfer function of drilled shafts in highly weathered rocks. Through comparisons with field case studies, it is found that the prediction by the present approach is in good agreement with the general trend observed by in-situ measurements.

• 대한수의학회지
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• 제36권4호
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• pp.859-871
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• 1996

This study was conducted to elucidate the distribution of Aujeszky's disease viral nucleic acids and antigens in the central nervous system (CNS) of piglets. The first Korean isolate of Aujeszky's disease virus(ADV) that isolated from naturally infected piglets in Yang San, was inoculated into 32 day old piglets with $10^{5.9}TCID_{50}/ml$ through intranasal or intramuscular route. These piglets were sacrificed at every 24hrs for 8 days. The immunohistochemistry (IHC) was conducted to detect the viral antigens in paraffin-embedded tissue sections using avidin-biotin-peroxidase complex (ABC) method. The viral nucleic acids were detected by in situ hybridization (ISH) using ADV specific DNA probe labeled with digoxigenin. The ADV antigens were detected in reticuloendothelial cells of spleen, lymph nodes and tonsil, alveolar walls, leptomeningeal vascular walls, inflammatory foci of each organ, and nerve cells. The viral nucleic acids were detected in the spinal trigeminal nucleus and its tracts of the pons and medulla oblongata by the ISH technique. The pathways of AD viruses in CNS were determined by IHC and ISH. In the intranasally inoculated group, the viruses in nasal mucosa moved to medulla oblongata and pons through the trigeminal nerve. In case of intramuscullarly inoculated group, viruses moved to brain via lymphoid organs or spinal nerves from sciatic nerves.