• 한국해양공학회지
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• 제23권2호
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• pp.18-27
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• 2009

This study was conducted to examine the effect of wind on the circulation of seawater in Gamak Bay, which contains numerous farms for fish and shellfish but suffers a significant loss by fisheries nearly annually from harmful algal blooms. In numerical experiments with a simplified bathymetry for Gamak Bay, the wind in summer appeared to more strongly influence the east-westward flow than the south-northward flow. In winter, this trend was nearly similar to the summer but seemed to have a greater effect on the flow at the north-west of the bay than the flow at the south mouth of the bay. On the other hand, in numerical experiments with a realistic bathymetry for Gamak Bay, the wind in summer appeared to more strongly influence the east-westward flow than the south-northward flow. Furthermore, the effect of the wind was stronger at the south mouth of the bay than at the north-west of the bay. In contrast, the wind in winter affected the east-westward flow more strongly and its effect appeared stronger at the north-west of the bay than at the south mouth of the bay. In addition, the effect of the wind tended to increase with distance from the east to the west. Therefore, the tidal currents in Gamak Bay proved to be strongly influenced by the wind, in particular east-westward. However, some measures are urgently required to improve the water quality of the bay, since the south-northward flow turned out to be obstructed by an east-westward shoal located in the middle of the bay.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
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• pp.513-513
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• 2004

Manila clam, Ruditapes philippinarum, is commercially and ecologically important marine bivalve in Korea and japan. However, clam landings in the two countries have dramatically declined since the 1980-1990's. In the present study, the protozoan parasite, Perkinsus sp., lectin (host's defense-related glycoprotein) and histopathological features were investigated in Manila clams collected from Gomso Bay in Korea and Ariake Bay in japan (one of the largest clam beds in each country) during summer and fall, 2002-2003. DNA sequences of non-transcribe spacer (NTS), internal transcribed space. (ITS) and 5.85 rRNA of Perkinsus sp. were identical to those of P. atlanticus that was reported in Europe and Korea. For diagnosis of Perkinsus, the fluid thioglycollate medium (FTM) and the 2 M NaOH lysis methods were used. Prevalence of the parasite varied from 92.5-98.7% in Gomso Bay and 35.5-37.9% in Ariake Bay. Infection intensity, in terms of the number of Perkinsuscells per gram tissue wet weight, in the clams of Gomso Bay in fall 2002 averaged 1,010,077-470,937 recording approximately100 times higher than that of Ariake Bay, and these were twice higher than those of summer samples in each location. Mean hemagglutination titer of the clams from Gomso Bay was approximately 60-folds higher than that of clams from Ariake Bay in 2002. In histological preparation of the clams from Gomso Bay in 2002, trophozoites of P. atlanticus were in groups and resulted in severe inflammatory response of host clam. Prevalence of the trematod, Cercaria tapes-like in the clams of Gomso Bay and Ariake Bay were 8.8 % and 10.5% respectively. In conclusion, the clams from Gomso Bay showed more severe pathologic symptoms and higher immune response than those of the clams from Ariake Bay.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.421-428
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• 2011

We conducted modeling experiments to evaluate the residence times and exchange rates of seawater in Gamak Bay, located on the southern coast of the Korean Peninsula. The results revealed that pollutants are more quickly dispersed in a fixed grid rather than in a variable grid system. Pollutant concentrations decayed exponentially with time after release near the mouth of the bay, whereas no exponential variations were seen at the northwest end of the bay. The mean exchange rate of the seawater was 1.58% per day in the variable grid system, and the residence time of pollutants was greater than 288 days in Gamak Bay. Conversely, the exchange rate of seawater in Gamak Bay, as revealed by the particle tracking method, was 65% over a 50-day simulation. The results suggest that the seawater exchange in Gamak Bay is so low that pollutants are likely to remain in the bay indefinitely.

• Fisheries and Aquatic Sciences
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• 제10권2호
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• pp.86-92
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• 2007

Adult Dungeness crabs are restricted primarily in the lower part of Glacier Bay, Alaska, but the interaction of larval dispersion and adult distribution is unknown. To understand the larval occurrence in the upper part of Glacier Bay, Dungeness crab larvae, sea surface temperature (SST), and sea surface salinity (SSS) were collected at 16 near-shore and 12 mid-channel stations in Glacier Bay, southeastern Alaska during six sampling periods from March through August 2000. Each station was visited from one to five times during the entire sampling period. Geographic Information System (GIS) was used to contour SST and SSS distribution in Glacier Bay. Seven to 27 stations were visited during each sampling period. Most larvae (85% were zoeae I) occurred during May 31 to June 14, 2000. Larval density varied from none to $51.4\;100\;m^{-3}$ between stations. A few later stage larvae occurred during later sampling periods. Overall, no relationship between larval densities, and SSS, and SST existed. Larvae occurring in the upper bay were probably transported by tidal currents from the lower bay; adult Dungeness crabs in Glacier Bay have a relatively high density near the mouth of the bay but decrease sharply around 40km north of the mouth. The lack of adult crabs in the upper 60km of the bay may be related to lower salinity, resulting in sharp haloclines, or colder temperatures which are not conducive to survival or growth of either larvae or adults.

• 한국습지학회지
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• 제11권2호
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• pp.39-46
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• 2009

가로림만은 주변으로부터 담수와 퇴적물의 공급이 거의 없는 전형적인 반 폐쇄성 만이다. 만에는 수로, 조간대, 사퇴, 섬 그리고 유입구 등 다양한 소환경이 있다. 만 환경의 질은 소환경의 해수 교환과 밀접한 관련이 있기 때문에 만과 외해와의 해수 교환을 정량적으로 파악하는 것이 필요하다. Hydro-hypsography는 각 수심에 대한 해수-표층 면적(water-surface area)의 상대적인 분포이다. 가로림만 Hydro-hypsographic curve에서 조간대는 전체 면적의 약 77 % 이다. 수리적 교환 시간(HTT: Hydraulic Turn-over Time)은 1.32 tidal cycle로 해수 유통이 좋은 지역으로 나타났다. Hydro-hypsometric 기법은 다양한 형태를 가진 만(bay)들의 건강성을 평가하는데 유용할 것이다.

• 대한교통학회지
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• 제20권3호
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• pp.31-39
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• 2002

본 연구는 신호교차로의 좌회전 용량을 파악하기 위하여 bay차로를 포함한 좌회전 이동류의 용량산정 모형을 개발하는데 목적이 있다. 본 연구에서는 신호교차로의 혼잡을 완화시키기 위해 설치 운용되고 있는 좌회전 bay 차로의 용량을 파악하여 보다 정확한 용량산정치 적용을 통한 교차로 운영의 분석자료를 제시하고자 한다. 연구방법은 좌회전 bay길이를 20∼120m까지 변화시키며, bay차로와 전용차로에 대한 차두시간을 분석하였다. Bay차로의 용량산정을 위해 차두시간과 차량유출행태 특성에 따라 1구간(출발손실구간:SLP), 2구간(포화차두구간:SFP), 3구간(차로선택구간:LSP)으로 구분하여 분석하였다. 수집된 차두시간 자료로 차량 대기위치순서별로 분석하였다 자료의 통계적 검증을 통하여 구간대별 평균차두시간을 설정한 후, bay길이별 용량산정 모형을 도출하였으며, 이를 이용하여 bay길이별 좌회전 용량을 산출하였다.

• Ocean and Polar Research
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• 제29권4호
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• pp.339-348
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• 2007

In this work, we compared the characteristics of three benthic biotic indices (BPI, AMBI, BIBI) which indicates the health condition of benthic communities in Masan Bay, Korea where anthropogenic impacts have been concentrated. Also we evaluated the usefulness of these benthic indices and some problems if they were applied to the Korean coastal waters. For this we used the macrozoobenthos data collected using van Veen grab ($0.1\;m^2$) at 21 sites in Masan Bay in February and August 2004. Based on the BPI values, two stations in the inner bay were found in a very hard polluted condition and three stations in the middle bay were also in a highly polluted condition. Only one station located in the bay mouth was in a normal condition. The inner bay stations showed very high AMBI values (${\geq}5.0$), indicating a highly polluted condition. The bay mouth station was assessed in a moderately polluted condition. The overall BIBI values in Masan Bay were in the range between 1.0 and 3.0. The inner bay stations showed low BIBI values (${\leq}2.0$) in the severely degraded condition. The bay mouth station with high BIBI value over 3.0 was assessed as a normal condition. All three benthos indices showed that macrozoobenthic communities in the inner bay were in a seriously polluted condition all year round, and macrobenthic faunas in the bay mouth seemed in a bad healthy condition (slightly polluted) based on AMBI during summer season. These three benthic biotic indices showed the similar assessment result, and thus we consider that each of them is a useful tool for the assessment of coastal benthic ecosystems under the organic enrichment in sediment.

• 한국건설관리학회논문집
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• 제20권1호
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• pp.52-61
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• 2019

2017년 6월 30일 국토교통부는 주차단위구획의 최소 크기를 확대하는 것을 입법 예고하였다. 주차단위구획의 확대는 주차장 연면적의 증가를 초래하여 아파트 분양가를 상승시킬 우려가 있다. 그러므로 주차장의 기둥 간격과 개수를 조정하고, 주차효율이 좋은 8-Bay 장스팬 주차모듈을 적용할 필요가 있다. 연구결과, 주차단위구획을 확대한 6-Bay 주차모듈과 8-Bay 주차모듈의 공사비는 거의 비슷한 수준이었으나, 8-Bay 주차모듈의 연면적 감소 효과가 확인되어 8-Bay 주차모듈이 더 경제적인 것으로 나타났다. 8-Bay 주차모듈의 공사비를 분석한 결과, 탈형데크플레이트 RC공법을 적용한 모듈이 가장 경제성이 있는 것으로 나타났다. PC 복합화공법은 부재의 체적 증가로 인해 비교적 공사비가 높게 나타났으나, 프리스트레스를 적용하여 보 춤을 감소시키면 경제성을 확보할 수 있을 것으로 확인되었다. 또한 중공슬래브 공법 모듈은 가장 공사비가 높게 나타났으나, $1m^2$당 공사비가 가장 낮아 비용적 측면에서 아파트 주차장의 구조공법으로 적용 가능성을 확인하였다. 이 연구는 8-Bay 주차모듈의 공사비를 분석하고 비용적 측면에서 경제성을 확인하였다는 점에서 의의를 가지며, 향후에 8-Bay 주차모듈을 적용한 최적의 공법을 도출하는데 기초자료로 활용될 것으로 기대된다.

• 한국산학기술학회논문지
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• 제10권5호
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• pp.1074-1081
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• 2009

반도체 공정시스템의 레이아웃은 대규모 자본 투자의 필요성과 제조 공정의 복잡성의 증가와 함께 그 중요성이 점점 증가하고 있다. 오늘날 대부분의 반도체 공정시스템은 같은 유형의 장비가 동일한 bay에 배치되는 bay 타입의 레이아웃 형태를 취하고 있다. Bay 타입 레이아웃은 유연성의 장점을 가지고 있지만 물류 흐름의 제어 측면에서는 많은 단점을 가지고 있다. 본 논문에서는 이러한 bay 타입 레이아웃의 단점을 보완하고자 bay 타입의 유연성은 유지하되 conter spine이 없고 bay를 통합한 형태의 새로운 반도체 레이아웃 개념인 room 타입에 대해서 비교, 연구한다. 이를 위하여 본 논문에서는 새로운 room 타입 레이아웃의 형태를 제시하고 이를 기존의 레이아웃과 반송필요 횟수와 시간, foot-print, 경유 stocker, 그리고 물류흐름 시간 등의 성과척도를 비교하여 room 타입 레이아웃의 우수성을 보인다.

• 한국환경과학회지
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• 제28권11호
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• pp.1005-1017
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• 2019

Environmental factors and changes in phytoplankton community structure before (August 5, 2017), during (August 18 and 25) and after (August 30 and September 15) freshwater input were analyzed to investigate the effects of freshwater input from Ganwol and Bunam lakes located in the upper part of Cheonsu Bay. Due to the large amount of freshwater input in the Cheonsu Bay, the surface salinity of the bay decreased by more than 8 psu, and the thermocline existing in the bay during August weakened. In addition, hypoxic phenomena occurred temporarily in the bay as the low oxygen water mass from the freshwater lakes flowed into the bay, and chemical oxygen demand, nutrients, and N/P increased with freshwater inflow. The density of phytoplankton during the freshwater inflow increased owing to their input from the freshwater lakes. Diatom species (Eucampia zodiacus) dominated the phytoplankton community in the bay before freshwater input; nanoflagellates, chlorophyta, cyanobacteria, and diatoms (Pseudonitzschia delicatissima, Chateocceros spp.) entered during freshwater input; and after freshwater inflow ended, diatoms (Chateocceros spp.) again became predominant indicating a return to previous conditions. The amount of phytoplankton standing crops increased sharply due to the inflow of freshwater species into the bay on the second day of discharge compared to before freshwater input; pre-discharge conditions were restored at most stations except at some sites close to the Bunam Lake three days after discharge. Therefore, the large amount of freshwater flowing into the bay affects not only the geochemical circulation in the bay but also the phytoplankton community structure. In particular, the high concentration of nutrients in the freshwater lake affect the marine ecosystem of the bay during August.