• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.937-941
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• 2007

For Hydrologic analysis of the river, the exact Dividing Watershed and Hydrologic-Topographical Parameters affect enormously Hydrologic analysis of the river basin. Therefore the extraction of Hydrologic-Topographical Parameters as well as Dividing Watershed are stiuied by several ways. However the definite standard of all those means are not settled. Recently GIS is applied to the field of water resources so that we can divide Watershed and calculate Hydrologic-Topographical Parameters of the targeted area easily and objective way for using DEM. Thanks to DEM, we don't have to spend much time as we did before. However other problems are generated such as the parameter value is changed by the precision of established NGIS(National Geographic Information System), etc. In this study, using GIS which is popular recently, we suggested efficient extract method of Hydrologic-Topographical Parameters SCS(Soil Conservation Service) CN(Curve Number) in watershed.

• Hwankyungkyoyuk
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• v.9 no.1
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• pp.58-71
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• 1996

The purpose of this study was to investigate the rural housewives' recognition and practice on environmental preservation. The subjects of this study were 300 rural housewives living in Chung-buk province. Questionaires were distributed to them during a week from August $25^{th}$ to August $31^{th}$ in 1995. Major findings were as follows: 1. The saved water quite well in washing their faces and the dishes compared with urban housewives, but they did not save water so well in using the lavatory. They used synthetic detergent, one of water pollutants, more often than natural soaps in shampooing and laundering. In addition, they did not use a measuring cup. It resulted in the waste of detergent and aggravation of water pollution. 2. Food waste was disposed of properly, but used batteries were not collected separately. A disposable vinyl bag was more commonly used than a reusable shopping basket. The reason for not using a shopping basket was bothering or uncustomary. Since most of them did not know refillable products of goods with environmental mark, they did not use those. Therefore, housewives should be educated in order to prevent soil pollution. 3. The use of spry-type pesticide and hair treatment, one of air pollutants, was wide-spread among them. They hardly recognized and practiced saving of electric power when they used household electric appliances. 4. The major source of environmental knowledge was mass media like TV of radio. Many of them did not know the practical ways to solve the environmental education program. In conclusion, low level of recognition and practice of rural housewives on environmental preservation indicated that a systematic environmental education program should be developed and implemented.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1142-1146
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• 2008

토양수분은 지표수의 유출과정을 설명하는 과정에서 중요인자이며, 생태수문학의 핵심변수이자 기상모형의 결정적인 입력변수이다. 또한 토양수분의 공간적 시간적 특징들은 강우 및 지하수와 토양수분간의 순환 구조를 규명하는데 매우 중요하다. 본 연구에서는 산지사면의 토양수분을 체계적으로 측정하는데 필요한 시스템의 구축을 위한 기초조사 및 사전분석에 대한 연구를 수행하였다. 우수한 토양 수분 측정 장비인 TDR 장비 매설에 앞서 대상유역 선정에 대한 여러 가지 고려사항을 검토하고 수치지형 분석 등을 통한 사전분석을 실시하였다. 대상유역을 선정하기 위해서는 대상유역의 자료획득의 용이함, 지정학적, 시스템 운영적 측면에서의 가용성, 그리고 정밀측량 및 부수적요인 등 여러 요소의 고려가 요구된다. 본 연구에서는 경기도 파주시 적성면 설마리의 설마천 유역내 감악산 범륜사 우측 산지 사면을 측정대상 사면으로, 지정학적 위치, 식생분포, 지질구조 및 심도 등의 토양특성의 고려를 통해서 선정하였다. 또한 대상 사면에 흐름 발생 및 분포를 계산하기 위해서 대상사면의 지표 및 기반암 표고를 정밀 측량하였으며, 기반암 또는 풍화대까지의 깊이를 실측하여 지표면 및 지하면의 수치지형 모형을 구축하였다. 이를 대상사면 및 지하면에 대하여 표고수치지형모형(Digital Elevation Model:DEM)으로 도식한 후 흐름 발생 공간 분포를 계산하였다. 흐름발생공간분포예측은 단방향 알고리즘, 다방향 알고리즘, 흐름 분배 알고리즘 그리고 다중무한방향 알고리즘을 사용하여 지형인자인 기여사면적과 지형습윤지수를 계산하였다. 각 분배알고리즘의 의해 도출된 지형인자들로 인한 흐름발생 공간적 분포특성을 비교하였다. 이는 합리적인 토양수분 측정시스템을 구축하는데 중요한 의사결정 수단으로 판단된다.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.3
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• pp.46-59
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• 1999

Remote sensing provides informations on the changes of the hydrological states and variables over with the temporal and spatial distribution to monitor hydrological conditions and changes for large area. Especially, it can extract a spatial distribution of hydrological parameters such as surface albedo, vegetation informations, and surface temperature to effectively manage water resources of the watershed. In this study, we analyzed the characteristic of temporal and spatial changes in surface hydrological parameters which is necessary to identify the spatial distribution of water resources. 5 Landsat TM data of 1995 which is collected for Bochong-chon watershed, located in the upper stream of Keum River, were used to estimate characteristics on the change of hydrological parameters and atmospheric correction was carried out using COST model. The study showed that the difference of the albedo by the land cover was very sensitive depending upon the change of sun elevation and the amount of water in the soil. The difference between the surface temperature analysis and the measured air temperature was from $2.5^{\circ}C$ to $3.86^{\circ}C$.

• Journal of dental hygiene science
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• v.3 no.1
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• pp.11-14
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• 2003

A methylotrophic Actinomycetes strain, which produce the anti-oral cancer activity compound, was isolated from soil and estimated as Amylocolatosis sp. based on taxonomic studies. A methanol didn't have influence on the production of the anticancer compounds. These compound were isolated by ethylacetate extract, silica gel column chromatography, sephadex LH-20 column and reverse phase HPLC. The compounds were very stable under heat ($121^{\circ}C$), acid(pH 2.0) and alkali(pH 11.0) treatment. The cytotoxic effect of isolated anticancer compounds on various cancer cell lines such as A549, SNU-1, KB, L1210, and Sarcoma 180 was investigated by MTT assay method. And these produced compounds also showed the broad antimicrobial spectrum to test strains such as bacteria and yeast.

• Geotechnical Engineering
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• v.3 no.1
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• pp.39-52
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• 1987

Model pile tests are performed, first, to estimate donwndrag exerted on pile surfaces due to the settlement of surrounding soils, and, second, to evaluate the efficiency of the downdrag reduction methods such as the bitumen coating method and the method of the attachment of an enlarged base. Test results show that the downdrag forces may be expressed as 0.25(;effective overburden). Bitumen coating reduces the downdrag by more than 50 percent, and the enlarged base attachment method is also effective, whose effectiveness increases as the sixte of the base increases as expected. When the bitumen coating and enlarged base are both applied, the downdrag force is reduced as much as 90 percent. Finally, it is found that the quantity of the relative displacement between the pile and the surrounding soil downdrag is extremely small.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.351-361
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• 2003

Brick wall models with window opening, length 1.844m $\times$ height 0.6m, representing 2-story building was constructed on a scale of 1/10 of actual size of brick building for the investigation of damage mechanism. Six settlement troughs presenting six stages of excavation were simulated by Peck(1969) and O'Rourke et al.(1976) methods. The results from the model tests using Peck(1969) and O'Rourke et al.(1976) method indicated that angular distortion of brick wall by O'Rourke et at. method was 21% greater than that of Peck method. Horizontal displacement by O'Rourke et al.(1976) was 24% greater than that of Peck. When the degree of building damage for the O'Rourke et al. method of settlement trough is plotted on the damage level graph(Boscardin & Cording, 1989), damage level becomes much more severe than the level obtained by peck's method. Also, building stiffness and soil-structure interface are considered important factors of expressing building damage.

• Earthquakes and Structures
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• v.7 no.4
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• pp.485-510
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• 2014

In performance-based seismic design procedures Peak Ground Acceleration (PGA) and pseudo-Spectral acceleration ($S_a$) are commonly used to predict the response of structures to earthquake. Recently, research has been carried out to evaluate the predictive capability of these standard Intensity Measures (IMs) with respect to different types of structures and Engineering Demand Parameter (EDP) commonly used to measure damage. Efforts have been also spent to propose alternative IMs that are able to improve the results of the response predictions. However, most of these IMs are not usually employed in probabilistic seismic demand analyses because of the lack of reliable Ground Motion Prediction Equations (GMPEs). In order to define seismic hazard and thus to calculate demand hazard curves it is essential, in fact, to establish a GMPE for the earthquake intensity. In the light of this need, new GMPEs are proposed here for the elastic input energy spectra, energy-based intensity measures that have been shown to be good predictors of both structural and non-structural damage for many types of structures. The proposed GMPEs are developed using mixed-effects models by empirical regressions on a large number of strong-motions selected from the NGA database. Parametric analyses are carried out to show the effect of some properties variation, such as fault mechanism, type of soil, earthquake magnitude and distance, on the considered IMs. Results of comparisons between the proposed GMPEs and other from the literature are finally shown.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.6
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• pp.695-702
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• 2015

Recently, the improvement of mechanical and theoretical issues in geo-centrifuge test enhances the applicability and accuracy of the test. Geo-centrifuge test is appropriate to simulate the behaviors of underground structures like tunnel, since tunnel interacts with the soil and/or rock around it and the test can embody the in-situ stress conditions effectively. In this study, the seismic behaviors of twin tunnel were analyzed based on geo-centrifuge test. Flexible segment to mitigate seismic acceleration were implemented in the model with thin and thick thickness. Based on the test results, it was found that flexible segment can decrease the peak acceleration generally, however, thin flexible segment was not able to reduce peak acceleration in short-period seismic wave. Thick flexible segment was more effective in case of high bedrock acceleration condition. Additionally, 3-dimensional numerical analysis was performed to verify the characteristics of seismic behavior and the effect of flexible segment. Consequently, the numerical analysis result showed good agreement with the test result.

• Advances in Computational Design
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• v.3 no.1
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• pp.49-69
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• 2018

This paper shows an optimal design for reinforced concrete rectangular combined footings based on a criterion of minimum cost. The classical design method for reinforced concrete rectangular combined footings is: First, a dimension is proposed that should comply with the allowable stresses (Minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity withstand by the soil); subsequently, the effective depth is obtained due to the maximum moment and this effective depth is checked against the bending shear and the punching shear until, it complies with these conditions, and then the steel reinforcement is obtained, but this is not guaranteed that obtained cost is a minimum cost. A numerical experimentation shows the model capability to estimate the minimum cost design of the materials used for a rectangular combined footing that supports two columns under an axial load and moments in two directions at each column in accordance to the building code requirements for structural concrete and commentary (ACI 318S-14). Numerical experimentation is developed by modifying the values of the rectangular combined footing to from "d" (Effective depth), "b" (Short dimension), "a" (Greater dimension), "${\rho}_{P1}$" (Ratio of reinforcement steel under column 1), "${\rho}_{P2}$" (Ratio of reinforcement steel under column 2), "${\rho}_{yLB}$" (Ratio of longitudinal reinforcement steel in the bottom), "${\rho}_{yLT}$" (Ratio of longitudinal reinforcement steel at the top). Results show that the optimal design is more economical and more precise with respect to the classical design. Therefore, the optimal design presented in this paper should be used to obtain the minimum cost design for reinforced concrete rectangular combined footings.