• 대한조선학회논문집
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• 제45권6호
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• pp.688-694
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• 2008

The reduction of the structure-borne noise is very important in order to reduce the noise of a ship. The noise at the high frequency range usually comes from the fluid flowing. The noise from the sea-water conveying pipe is one of the main source on these high frequency range. Therefore, the transmissibility variations are evaluated according to the shape of the rubber mount. The evaluations are performed with the frequency response function numerically and experimentally.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.117-122
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• 2004

This study investigates the spatial and temporal distribution characteristics and relationships among water quality parameters, which based on 6 years' data(from 1989 to 1994) measured at 16 stations on Jinhae Bay. The results of these analysis, monthly variations range between surface and bottom layer of water quality had a tendency to increase and decrease, and appeared to be at the maximum value in August. The relationships between concentration of COD ana nutrients(DIN and DIP), which obtained by correlation analysis of water quality, were shown $85\%$ and $74\%$, respectively. Using the cluster analysis to develop the division of the sea basin by the dendrogram, before and after dredging of Masan bay and operating a sewage disposal plant, the variation characteristics of water quality of Jinhae Bay were discussed. Through it, we can see the serious pollution of northen sea basin of Jinhae Bay(B2) although dredging Masan bay and operating the sewage disposal plant. As the results, it doesn't appear the improvement effect of water quality in spite of carrying out the effort of water quality improvement.

• 한국물환경학회지
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• 제24권6호
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• pp.651-658
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• 2008

Estuary barrier is a hydraulic structure constructed to supply safely water as protecting chlorine penetration of sea water. However, the barrier brings about a problem which decreases original functions of estuary because hydraulic ecology was disrupted as obstructing natural water exchange between fresh water and sea water. It is important to supply Enough fresh water in the estuary ecosystem. But it is possible to reduce the problems brought from barrier throughout efficient water gate operation of estuary barrier. It was shown in this study that the environmental effect of estuary in Nakdong river was investigated according to the control of water level. Also, the basic information about the effective water gate operation was provided. The analysis results showed that the release rate of estuary was increased about 20% as changing the operational water levels. This helps supplying fresh water durably to the mixing zone. Also, CE-QUAL-W2 model was utilized to assess water quality. The values of BOD and COD were not changed in estuary area. From the result, it was analyzed the effect of water quality according to the water gate operation was not indicated.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.285-289
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• 2004

Oceanographic observation and qualitative analysis for deep ocean water in the East Sea were carried out from January 2003 to January 2004, in order to understand the characteristics of deep sea water in the East Sea. Temporal and spatial variation of water masses were discussed from survey of the study area including the coastal sea of Kwangwon province in where the polar front mixing cold and warm water masses were formed. On the basis of the vertical profiles of temperature, salinity and dissolved oxygen, water masses in the study area were divided into 5 major groups; (1) Low Saline Surface Water (LSSW) (2) Tsushima Surface water (TSW) (3) Tsushima Middle Water (TMW) (4) North Korea Cold Water (NKCW) and (5) East Sea Proper Water (ESPW). In winter, surface water in coastal sea of Kwangwaan Kosung region were dominated by North Korean Cold Water (NKCW). As Tsushima warm current were enforced in summer, various water masses were vertically emerged in study area, in order of TSW, TMW, NKCW and ESPW. It is highly possible that the LSSW which occurred at surface water of september is originated from influx of fresh water due to the seasonal rainy spell. Nevertheless water masses existed within surface water were seasonally varied, water quality characteristics of East Sea Proper Water (ESPW) under 300 m did not changed all the seasons of the year.

• 한국식품영양학회지
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• 제16권1호
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• pp.66-71
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• 2003

요구르트의 기능성을 증가시키고 동시에 요구르트의 안정성을 높일 목적으로 다시마 열수 추출액으로부터 요구르트를 제조하여 그 품질의 특성을 조사하였다. 실험구 중 0.5% 다시마 열수 추출액으로 제조한 요구르트의 적정산도가 1.89%로, 다시마 열수 추출액 무첨가구의 적정산도 1.53%보다 높은 것으로 나타났으며, 젖산균의 생육은 다시마 열수 추출액으로 촉진되어 무첨가구의 4.4$\times$$10^{8}$ CFU/$m\ell$보다 0.5%다시마 열수 추출액 첨가구가 1.4$\times$$10^{9}$ CFU/$m\ell$로 가장 높았다. 다시마 요구르트의 점도는 0.5%의 다시마에서 25 cps로, 무첨가구의 22 cps보다 높았으나 1.0% 다시마구에서는 무첨가구의 점도와 비슷한 21.5 cps로 나타났다. 7$^{\circ}C$에서 15일간의 저장시 다시마 요구르트는 pH, 산 생성 및 생균수에 거의 변화가 없어 우수한 것으로 나타났다. 커드의 침전은 0.5% 다시마 열수 추출액으로 다소 억제시킬 수 있었으며, 관능검사에서 무첨가구에 비해 1%다시마 첨가구를 가장 선호하는 것으로 나타났다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_3호
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• pp.97-106
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• 2001

To improve the water quality, particularly for sea bathers, the behaviour of wastewater from sewage outfalls in water adjacent to Swansea, UK, was studied using a mathematical model. The water quality in the sewage receiving basin was determined using factors like the outfall diffuser location(distance from land boundary), sewage treatment scheme, discharge time, and bacteria decay rate, etc. With respect to these factors, an optimal strategy for sewage discharge was then investigated to minimize bacteria levels along the bathing beaches. As water quality criteria, predicted faecal coliform levels were monitored along the coast adjacent to the outfall locations. The resultant values were compared with EC Mandatory(<2000, 95 % of 20 samples) and Guideline Standards(< 100, 80 % of 20 samples). For the advective-diffusion equation, the non linear advective terms were represented using the ULTIMATE algorithm and the third-order accurate QUICKEST scheme to avoid numerical diffusion. Details of the simulation results are then presented as an optimal policy for sewage discharge in the region.

• 해양환경안전학회지
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• 제19권5호
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• pp.439-458
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• 2013

본 연구에서는 2010년부터 2011년까지 2년 동안 천수만 수질환경의 시공간적 특성을 조사하였다. 16개 정점에서 수층(표층과 저층)별 격월별로 년 6회 수온, 염분, 부유물질, 화학적산소요구량, 용존산소, 영양염류, 엽록소 a 에 대해 조사한 결과, 표층수와 저층수 간에는 아질산질소, 질산질소 및 용존무기질소을 제외한 모든 조사항목에서 표 저층 간의 차이가 컸었다. 공간적 분포특성은 전조사 항목에서 정점 간 차이가 적었으나, 주성분 분석결과 표층에서는 부남호 영향을 받는 정점 1 과 중간역인 정점 2~11 및 입구쪽인 정점 12~16로 구분되어지고, 저층에서는 표층과 마찬가지로 정점1과 죽도 북측연안의 정점 2~7 및 정점 8~16의 세 그룹으로 구분되었다. 격월별로는 저층의 부유물질을 제외한 전조사 항목에서 유의성이 입증되었으며, 정점별로 차이가 있어 내측은 격월별 변화가 큰 상태이었고 입구측으로 갈수록 변화폭이 줄어드는 경향이었다. 수질의 시간적 변동은 표층과 저층에서 세 그룹으로 구분되어지나 경향은 차이가 있었으며 대부분의 조사월에서 영양염류가 낮은 상태이었다. 생태기반 해수수질 기준은 II등급(좋음) 수준이며, 격월별로는 6월과 8월은 III등급(보통), 10월과 12월은 II등급(좋음), 2월과 4월은 I등급(매우좋음)으로 구분되어 경인연안, 아산연안, 목포연안 및 군산연안과 마찬가지로 육수 유입의 원인에 기인한 것으로 사료된다.

• 해양환경안전학회지
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• 제24권4호
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• pp.451-458
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• 2018

인천연안은 인천광역시, 경기도 김포시 시흥시 안산시 일대로, 양식장에서 발생하는 쓰레기, 어업활동 후 버려진 어구 어망, 육상에서부터 한강을 타고 흘러오는 쓰레기 때문에 인천연안의 해양생태계의 변화가 우려되고 있다. 인천연안이 심각하게 오염되자 해양수산부는 인천연안을 특별관리해역으로 지정하여 해양환경 자산인 해역수질을 보존하고 있다. 이러한 배경 하에서 본 연구는 인천연안 해역수질의 비시장 가치를 선택실험법(choice experiment)을 이용하여 평가한다. 이를 위해, 전국 1,000 가구를 대상으로 면대면 설문조사를 실시하였고, 속성 각각의 한계지불의사액(MWTP, marginal willingness to pay)을 추정한다. 인천연안 해역수질의 속성별 가치(가구당 연간 한계지불의사액)를 추정한 결과, 가구당 연간 해역수질 1 %p 개선의 MWTP는 75원, 동물종의 다양성 증가의 MWTP는 135원, 식물종 다양성 증가의 MWTP는 309원, 해양쓰레기 1 %p 저감의 MWTP는 72원으로 나타났다. 모든 추정결과는 유의수준 1 %에서 유의한 것으로 나타났다. 본 논문의 주요 결과는 정책당국에 해양환경 관리정책 수립과 평가에 유용하게 활용될 수 있다.

• 해양환경안전학회지
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• 제20권6호
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• pp.640-645
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• 2014

본 연구는 2010년 1월부터 12월에 걸쳐 우리나라의 서남해역에 위치한 인공적으로 조성한 해수욕장에서 수색변화와 저층바닥의 해조류의 번식 등의 문제점을 해결하기 위해 SS, COD, $NH_4{^+}-N$, TP, MPN과 저질 조사를 통해 해수욕장의 적합성을 판정하고 수질관리 방안을 제안하고자 하였다. 조사 결과, MPN 기준에는 만족하였으나 높은 농도의 SS와 TP로 인해 관리요망의 수준 이하로 확인되었다. 수질오염의 주요 원인은 해수 순환의 악화로 인해 해수가 장시간 체류되어 수온이 상승하고 침강된 퇴적물이 재 부유되어 수색이 변하고 탁도가 악화되며 저층 바닥에 해조류가 발생되고 있는 것으로 밝혀졌다. 이러한 문제점을 개선하기 위해서는 우선 해수의 유통을 원활하게 하고 오염된 퇴적물을 준설하거나 피복 또는 저질개선제를 투여하는 방법이 적용될 수 있으며 해수욕장으로 유입되고 있는 점원과 비점오염원을 저감 차단해야 될 것으로 판단되었다.

• 한국수산과학회지
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• 제44권6호
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• pp.612-621
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• 2011

The influences of inland pollution sources because of rainfall events on the bacteriological water quality in Geoje Bay, a major shellfish production area in Korea, were investigated. The sanitary status of sea water and shellfish after rainfall events was also evaluated. The flow rates of 13 streams around Geoje Bay showed 6 to 7-fold increases after 15 to 21 mm of rainfall. Peak pollution was observed in the Naegan Stream, the Gandeok Stream and the Seojeong Stream. The calculated impact area of inland pollution sources was 3.1 $km^2$ immediately after 15 mm of rainfall and expanded to 3.5 $km^2$ after 24 hours. These calculations of impacted area matched results from fecal coliform analyses with sea water. The distance between the major pollution source in the bay (the Gandeok Stream) and the station with the worst bacteriological water quality immediately after 15 mm of rainfall, which was below the Korean standard, was 0.8 km in a straight line; this distance increased to 2.0 km after a period of 24 hours. The area impacted by inland pollution sources after a 15 mm rainfall event was wider than after a 21 mm rainfall. Although the flow rate from inland pollution sources was higher, the concentration of fecal coliform in the discharged water was lower after higher rainfall events. These observations corresponded with the results of fecal coliform analyses with sea water samples. According to the evaluation of the influences of inland pollution sources and fecal coliform analyses on sea water and shellfish samples in Geoje Bay, pollutants from inland sources did not reach the boundary line of the shellfish growing area after rainfall events of 15 or 22 mm. The bacteriological water quality of the shellfish growing area in Geoje Bay met the Korean standard and US NSSP requirements for approved shellfish growing areas.