• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.04a
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• pp.15-17
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• 1999

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.385-386
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• 1998

• The Journal of Engineering Geology
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• v.9 no.2
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• pp.161-176
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• 1999

The objectives of this study are to analyze the changes of geo-surface topography in the Siwha embankment and the Ahsan city area by the image processing of Landsat Thematic Mapper data, and to estimate the reclaimed amount of the exposed tidal flat in the Siwha area using the GIS. False color composite, Tasseled cap, NVDI(normalized difference vegetation index), and supervised classification techniques were used to analyze the distribution of sediments and the aspect of topographical variations caused by artificial human actions. The total amount of the exposed tidal flat was estimated on the basis of the database snch as aerial photography, hydrographic chart, geological map, and scheme drawing in the Siwha area. The possible excavation regions for a seawall were predicted analyzing the supervised classification image of Landsat TM data. Tasseled cap images were used to observe the distribution of sediments. The difference of the NDVI images between spring and summer seasons indicates that deciduous and coniferous forests were distributed over the whole areas. The total fill-volume of the exposed Siwha tidal flat and the fill-volume of the construction planning seawall were calculated as $581,485,354\textrm{m}^3{\;}and{\;}3,387,360\textrm{m}^3$, respectively, from the digital terrain analysis. Daebu Island, Sunkam Island, and the part of Songsan-myeon were chosen as the cut area to make the seawall, and their cut-volumes were estimated as $5,229,576\textrm{m}^3,{\;}79,227,072\textrm{m}^3,{\;}and{\;}47,026,008\textrm{m}^3$, respectively. Therefore, the cut-volume of Daebu Island alone among three areas was sufficient to make the seawall.

• Ocean and Polar Research
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• v.25 no.spc3
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• pp.353-360
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• 2003

Estimation of undrained shear strength $(S_u)$ of clayey soils from piezocone penetration test (CPTu), which has widely been known as one of very promising in situ test methods, requires piezocone factors. Empirical correlations are generally utilized to derive piezocone factors, but previous studies on the empirical piezocone factors are site-specific and in some cases need engineering characteristics, which should be obtained from additional laboratory tests. In this study, empirical cone factors were evaluated by comparing 6 CPTu results at Shihwa region in Korea with reference $S_u$ values obtained from field vane test (FVT). From previous CPTu results of other regions in Korea as well as the results herein, the correlations between piezocone factor, $N_{kT}$ and CPTu results were investigated and three simplified evaluation methods of $S_u$ using only CPTu results were presented. The $S_u$ values estimated by $(q_T-{\sigma}_v)/{\sigma}'_v$ method shows better matches with those obtained from laboratory tests for marine clays at Shihwa region.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5957-5962
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• 2011

In this study, the values of the four kinds of cone factors($N_{kt}$, $N_{ke}$, $N_{{\Delta}u}$, and recently proposed $N_e$) and the soil properties, for the northeastern part of Shiwha area, were investigated. The measured and calculated undrained strengths, which have been obtained from the various experimental data, were compared with each other, and their relationship with the plastic index was also studied. The strength from the $N_{{\Delta}u}$ method was unexpectedly not reasonable and the higher values of cone factors were observed with the larger plastic index.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.04a
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• pp.181-183
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• 1998

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.359-364
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• 2002

This study was conducted to examine the seasonal pattern of N and P uptake by reeds (Phragmites australis) planted in newly constructed Shihwa tidal freshwater marshes. Reed and soil samples were collected from the wetland periodically from June 2000 to May 2002. Reed samples were analyzed for dry weight and content of N and P Soil organic matter content and salinity were also determined. Dry matter content of reed increased during the growing season but decreased in the fall and winter. However, this seasonal pattern was not so evident in the second year. In particular, throughout the measurement period, dry matter content of reed was lowest at a site showing high soil salinity. Regression analyses between dry matter content of reed and soil EC(1:5) suggested that dry matter content per unit square meter would decrease by 1.5 kg with every 1 dS m/sup -1/ increase in soil EC(1:5). The amount of N and P assimilated by reed significantly decreased from the fall and was lowest in the spring. Net decrease in N content from reed during the fall and next spring was calculated as 34.5 and 24.6 g m/sup -2/ in the first and second years, respectively, while the corresponding P loss was 4.0 and 1.8 g m/sup -2/. Soil organic mailer content increased in the fall and winter, but decreased in the spring and summer. The results of this study suggested that the removal of N and P by reed would be considerable during the growing season but the nutrients taken up by reeds would return as detritus to the marshes in the fall and winter. Based on the results of the study, therefore, the harvest of the reed at the latter part of the growth would be recommended to prevent further water quality degradation. However, the long-term effects of reed harvest needs further study.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.773-780
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• 2003

The characteristics of soft clays is very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the disturbed clay samples obtained from Sihwa area. This study included X-Ray Diffraction Analysis, X-Ray Fluorescence Spectrometer Analysis, Scanning Electron Microscopy Analysis and Energy Dispersive X-Ray Spectrometer Analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.356-358
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• 2000

ISC3는 EPA가 권장하는 가우시안 대기확산 모델로서 일반적으로 공장 배출원으로 인한 일정 기간동안의 대기확산농도와 범위를 예측하기 위하여 사용되어진다. ISC3 모델은 다양한 점오염원, 면오염원, 등을 취급할 수 있을 뿐 아니라 building wake와 down wash 그리고 거리의 함수로써 final plum rise를 옵션으로 사용할 수 있고 단순지형이나 복합지형의 고려가 가능하다. ISC3 모델은 단순지형 장기모델인 ISCLT3와 복합지형 단기모델인 ISCST3가 있으며 모델의 수행에 있어 약간의 차이점이 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.108-109
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• 1999

우리나라는 1960년대부터 시작된 산업화와 도시화의 결과 대도시, 공업단지의 대기오염이 매우 심각한 상황으로 최근 들어 대기질 개선을 위하여 유해 물질에 대한 배출을 엄격히 규제하고 있다. Beer-Lambert 법칙에 근거하여 측정 대상 물질에 의한 빛의 흡수가 파장에 따라 달라지는 것을 응용한 DOAS 측정 방식을 통한 대기오염의 측정은 선진국에서 이미 1970년대 후반에 연구, 개발되어 왔으나, 우리나라에서는 DOAS 부분의 연구가 매두 미진한 실정이다.(중략)