• Radiation Oncology Journal
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• v.16 no.3
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• pp.325-335
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• 1998

Purpose : Since the mid cranial fossa is composed of various thickness of bone, the tissue inhomogeneity caused by bone would produce dose attenuation in cobalt-60 gamma knife irradiation. The correction factor for bone attenuation of cobalt-60 which is used for gamma knife source is -3.5$\%$. More importantly, nearly all the radiosurgery treatment planning systems assume a treatment volume of unit density: any perturbation due to tissue inhomogeneity is neglected, This study was performed to confirm the bone attenuation in mid cranial fossa using gamma knife. Materials and Methods : Computed tomography was performed after Leksell stereotactic frame had been liked to the Alderson Rando Phantom (human phantom) skull area. Kodak X-omat V film was inserted into two sites of pituitary adenoma point and acoustic neurinoma point, and irradiated by gamma knife with 14mm and 18mm collimator. An automatic scanning densitometer with a 1mm aperture is used to measure the dose profile along the x and y axis. Results : Isodose curve constriction in mid cranial fossa is observed with various ranges. Pituitary tumor point is greater than acoustic neurinoma point (0.2-3.0 mm vs 0.1-1.3 mm) and generally 14 mm collimator is greater than 18mm collimator (0.4-3.0 mm vs. 0.2-2.2 mm) Even though the isodose constriction is found, constriction of 50$\%$ isodose curve which is used for treatment reference line does not exceed 1 mm. This range is too small to influence the treatment planning and treatment results. Conclusion : Radiosurgery planning system of gamma knife does not show significant error to be corrected without consideration of bone attenuation.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.94-100
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• 2013

In this study, we have investigated the water quality and flow rate at the 3 sites of main stream and 11 sites of the branch stream of Hwang River from January, 2007 to 2010, and analyzed the effects on Hwang River with the purpose of using the data for as the fundamental information for water quality improvement and water resource management in the water system of Hap-Cheon Lake Upper Stream. The flow rate at 3 sites of the main stream and 11 sites of the branch stream increased during the rainy season between June and September, and continuously decreased during the dry season starting from autumn to winter. The results of correlation analysis with Pearson correlation coefficient showed that $BOD_5$ and $COD_{Mn}$, $BOD_5$ and T-P, and $COD_{Mn}$ and TSS at the 3 sites of the main stream had high correlation with each other. We have also analyzed the correlation between Chl-a and major factors at the 3 sites of the main stream. Chl-a and the water temperature Negative correlation coefficient and that of Chl-a and $BOD_5$, $COD_{Mn}$ Positive correlation coefficient showed. The N/P ratio at all the 3 sites of the main stream was higher than 16 by DIN/DIP and T-N/T-P, indicating that phosphorus is acting as the limited nutrient.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.442-446
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• 2003

이 연구는 제주도 한림 지역에서 지하수의 수질과 오염의 특성을 규명하고자 시행되었다. 2002년 8월과 11월에 걸쳐 34개 지점에서 지하수 시료를 채취하였고, 이를 분석하여 지하수의 수질을 유형별로 분류하였다. 연구지역은 주로 (Na,Mg)-HCO$_3$ 유형이 나타나며, 일부 지점에서는 Mg-(HCO$_3$+Cl), (Ca,Mg)-HCO$_3$ 유형 등이 나타난다. 이는 지하수의 유동 경로를 따라 서로 다른 수리지화학적 반응이 일어나며, 지표 오염물질의 유입 등이 지하수의 수질에 영향을 미치고 있음을 지시한다. 질산성 질소의 경우, 국내 먹는물 수질기준치 10 mg/L를 초과한 시료는 전체 시료의 8월 조사에서 약 32%, 11월 조사에서 약 27% 이었고, 공간적 분포 특성은 비교적 낮은 고도 150m 이하의 저지대에서 채취한 시료에서 주로 나타났다. 인위적인 오염물질의 유입 가능성이 있는 지점은 전체 시료의 79.4% 이었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.810-814
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• 2007

최근 제방개수 혹은 하폭확장과 같은 기왕의 제방대책을 적용하기 힘든 도시지역의 홍수피해 저감방안의 일환으로 개수로 혹은 지하터널 형식의 방수로와 같은 구조적 대안이 제시되고 있다. 현재 국내에서 검토되고 있는 방수로의 형식은 주로 유입부와 유출부의 양 지점 수두차에 의한 만관 상태의 흐름형식이다. 본 연구에서는 수두차에 의한 만관 상태의 흐름을 가지고 있으며, 3개 지점이상의 유입부를 가진 지하터널 형식의 방수로 계획시 마찰손실, 유입손실, 만곡부손실 등을 고려하여 유입부, 유출부 지점 계획에 따른 터널의 연장, 직경 등 제원 결정을 위하여 기존에 제시되어 있는 2개 저수지 유입시 정상상태 만관 흐름해석방법을 확장하여 3개 이상 저수지 유입시 정상상태 만관 흐름해석을 할 수 있도록 하였다.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.119-128
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• 2001

A biological assessment of water quality was carried out in the Pyungchang River water system, Gangwon-do, Korea from September 1999 through August 2000. The benthic macroinvertebrates collected seasonally from 15 field sites were identified mostly up to species level. Benthic macroinvertebrates composed of 109 species, 77 genera, 31 families, 10 orders, 4 classes in 4 phyla. Dominant species occurring in all the field sites were mostly ephemeropterans and trichopterans. On the basis of the values of species diversity and biological indices such as Trent Biotic Index (TBI) Modified Biological Monitoring Working Party Score System (BMWP) and Biotic Index (BI), the Pyungchang River Water system was generally regarded as showing oligosaprobic water quality.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.970-970
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• 2012

최근 치수의 기능을 수행하면서 원래 자연하천의 모습을 보전 혹은 복원하는 "생태하천 복원 공법"의 필요성이 대두되고 있으나 구체적인 공법에 대한 연구는 미미한 실정이다. 본 연구에서는 하천 내 시설물의 조성 시 유황에 따른 자연 하안 유도와 습지형태의 생물 서식공간 조성 유무를 평가하기 위하여 평창강 일원에 목재 유도틀을 설치하고 이에 따른 지형변화, 저서무척추동물을 포함한 수생생물들의 서식특성을 분석하였다. 평창강 금당계곡 일원을 대상으로 RMA-2 모형의 범용프로그램인 SMS 모형을 통해 수리 특성분석을 실시하였고 안산에 있는 수리모형 실험장에서 기본 수리특성 실험 후 수리적 안정성이 확보된 지점에 목재 유도틀을 2009년 9월에 설치하여 유도틀 설치 전과 설치 후 2010년 10월까지의 지형변화를 분석하였다. 지형의 측량은 광파측정기(니콘 DTM-520)로 하였으며 측량된 자료를 이용하여 Contour Map을 작성하여 지형변화를 분석하였고, 유도틀 설치지역을 중심으로 2010년에 3차에 걸쳐 지형 및 생물상 변화에 대한 정량 및 정성조사를 실시하여 비교분석 하였다. 유도틀 설치 후 2010년 하절기에 집중호우에 의한 유도틀의 파손 및 형태변형 등 문제가 없어 수리적으로 안정한 것으로 판단되었다. 지형 변화의 측면에서는 유도틀 조성 전 사질로 되어있던 단순한 선형의 하안이 유도틀 설치 후 다양한 하상재질 및 형태가 변화했으며 유도틀의 배치에 따라서 굼치 및 둠벙형 습지가 형성되었다. 유도틀 설치지역의 3개지점(상부, 중간배후습지, 하부)에서 저서무척추동물에 대하여 모니터링한 결과, 설치된 유도틀의 중간지점에서 가장 높게 종의 서식이 확인되었으며 상부지점과 하부지점은 상대적으로 낮게 나왔으나 상부지점 보다는 하부지점이 양호하게 나타났다. 조사시기별 개체수의 변화에서는 종수변화와 패턴이 유사하게 나타났으며 깔다구와 꼬마줄날도래등 특정종의 증식이 많았다. 또한, 굼치 및 둠벙형 습지 내에 어류의 치어 및 유어, 양서류, 파충류등 다양한 생물의 서식이 확인되었다. 이는 유도틀에 의해 생성 및 유도된 지형변화가 하천을 기반으로 생활하는 생물들에게 다양한 피난처 및 은신처 역할을 잘 제공하고 있음을 보여준다.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.125-137
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• 2008

This research aims to produce basic data for developing habitat suitability models on the breeding sites of Oriental White Storks(Ciconia boyciana) which will be reintroduced to the wild in the future. The habitat characteristics of ten historical nesting sites of the Oriental White Storks at Gyeonggi and Chungcheong provinces in South Korea were analyzed with 1970's land use maps and Landsat MSS. The range of altitude on nesting sites was 40~116.38m. The mean distance from nesting sites to rice fields, to 30m wider river, and to reservoirs was $54.8{\pm}84.48m$, $869.8{\pm}708.01m$, and $1721.2{\pm}906.05m$ respectively. Historical nesting sites were located close to human settlements, and the mean distance of nesting sites to human settlements was $144.1{\pm}182.97m$. The land types within 5km radius from ten historical nesting sites consisted of 53.7% forest, 28.3% rice fields, 16.7% grasslands, 0.8% water bodies, and 0.6% human settlements. The composition of four land types(forest, rice fields, grasslands, and human settlements) was significantly differed between 93 random points and 10 historical nesting sites.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.341-347
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• 1998

This study was carried out to investigate the effect of U-Granule formulation of molinate(S-ethylhexaphdro-1H-azepine-1-carbothioate) mixtures in green house and paddy field, Five minutes were taken for U-Granule to spread out 7m in irrigated water of direct seeded on flooded paddy surface. The concentration of active ingredient of molinate in molinate U-Granule application was similar to molinate+simetryn U-Granule application. But weeding effect of molinate+simetryn U-Granule on Echinochlor crus-galli was 23% higher Than single application of molinate at 7m from application point. Bioefficacy of molinate+simetryn+imazosulfuron U-Granule on control of Echinochloa crus-galli was higher than that of molinzte+imazosulfuton U-Granule, but those effect on Eleochairs kuroguwai was not significantly different. Only slight rice phytotoxicity was observed at 5m and 2m from application point of U-Granule molinate+simetryn+imazosulfuron and molinate+imazosulfuron, respectively. So it is concluded that there is little phytotoxicity problem in practical application of U-Granule of molinate mixtures.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.10
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• pp.1006-1012
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• 2008

The effect of small and medium scale shipyard operations on environmental pollutions related with civil appeal of nearby residential areas was estimated. PM-10(particles with an aerodynamic diameter less than or equal to 10 $\mu$m) concentrations were higher, as the sampling sites were nearer from shipyards. PM-10 concentrations of sampling sites closer to shipbuilding companies were higher during the normal operation periods than on vacation at which only small works were done. The larger amount of dry deposition was observed as the sampling sites were closer to shipyards. The odor intensity was highly influenced by ambient temperature. Almost all odor intensities measured by air dilution sensory test went over the emission standard in summer. Odor properties measured by instrumental analysis were observed to exceed the emission standard enforced to the shipyards. Odor compounds such as ammonia, sulfur compounds and trimethylamine went over the standard. Concentrations of styrene and aldehydes were lower than the olfactory threshold. All equivalent sound levels measured at daytime except the value of SP-3 pont were in excess of the environmental standard. Almost all sound levels at nighttime in all measuring sites were higher than the environmental standard. The results of this study shows counterplans need to be established for reducing the civil appeal related pollutions in the research areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6943-6951
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• 2014

The trophic state assessment of the Hwoiya reservoir was estimated using the Trophic state indices (TSIs) of Carlson and Aizaki using the transparency and concentrations of chlorophyll-a and total phosphorus obtained from two sites of the reservoir. The TSIs assessments showed that eutrophic phenomena occur frequently in the Hwoiya reservoir. In addition, strategies to reduce the phosphorus especially would be prepared because the Hwoiya reservoir exceeded phosphorus-limiting state of 17 < TN/TP (total nitrogen/total phosphorus). Three scenarios for a simulation of the dredging effect of sediments on the water quality using the WASP7 model were made at two sites, which were 10% (scenario 1), 40% (scenario 2) and 60% elution of the pollutants from sediments (scenario 3). In the most elution case (60%), scenario 3, it was considered that 6.4% TN and 9.3% TP at site 1, and 3.9% TN and 5.6% TP at site 2 could be reduced.