• 한국지구과학회지
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• 제27권3호
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• pp.328-340
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• 2006

강화도 장화리 니질 조간대의 계절 변화에 따른 지형 변화와 퇴적 환경을 알기 위해서 4개 측선의 지형 변화, 112점의 표층 퇴적물 그리고 2점의 주상 퇴적물을 얻어 퇴적학적 분석과 방사선 동위원소 분석을 수행하였다. 표층 퇴적물은 크게 4가지의 퇴적상 즉, 사질, 니질 사, 사질 니, 실트로 나누어졌다. 장화리 조간대는 겨울철로 갈수록 표층 퇴적상이 조립해지고, 조간대 경사가 급해지는 등 전형적인 계절적 변화가 나타났다. 주상퇴적물에서 전체적인 퇴적상은 실트가 우세하고 분급은 불량하였다. Pb-210 동위원소를 분석한 결과 강화도 조간대의 평균 퇴적속도는 약 5 mm/yr로 나타났다. 또한 주상시료 최상부 퇴적상의 차이는 최근 이 연구 지역의 급격한 퇴적환경 변화를 지시하며, 이는 최근 주변 해역의 대규모 연안 개발 사업과 연관되어있는 것으로 사료된다.

• Journal of KIEE
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• 제11권1호
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• pp.32-40
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• 2001

This paper presents the detailed statistics on radiation field signatures associated with multiple-intracloud lightning discharges. A transient signal recording system was used to measure the electric and magnetic fields produced by lightning flashes. The measurements were made in th summers of 1995 through 1999, and the location of the observation station was in Inchon on the coast of the Yellow Sea in Korea(37$^{\circ}$25'N, 126$^{\circ}$ 39'E). Most of lightning flashes typically contains between two and five strokes. The individual intracloud stork radiation fields were the bipolar pulse. On the average, the ratio of the peak of the second stroke to the first stroke peak was 75.1$\pm$40.1% for the negative, and a fraction of the subsequent stroke peaks were higher than the first stroke peak. The greater the number of the subsequent stroke order, less time separations between strokes were produced. The mean of the depth of the dip was 81.2$\pm$27.9% for the positive polarity and 75.9$\pm$24.4% for the negative. The depth of the dip increased for the positive bipolar pulses and decreased for the negative as the number of the stroke order increased.

• 지질공학
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• 제16권2호
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• pp.161-169
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• 2006

곰소만의 기반암과 상부 층서들을 규명하기 위해 짧은 측선의 탄성파 반사법탐사가 수행되었다. 이 연구는 주로 자료 처리에서 신호대잡음을 높임으로써 기반암을 규명하는데 초점을 두었다. 자료처리의 주요과정은 종합 전후과정에서 모두 큰 진폭의 잡음에 가려진 신호성분을 향상시키는데 중점을 두었으며 시변필터, 불량 트레이스 제거, f-k 필터와 NMO 보정 후의 뮤팅 등이 이에 포함된다. 이 연구에서 규명된 기반암과 상부 층서들은 이전에 수행된 MT자료의 결과와 대체로 일치하며 당시에 자료질의 한계로 규명되지 못한 측선 중앙부근에서 기반암 표면이 약 30m 깊이의 수평층으로 나타났다.

• 한국해양환경ㆍ에너지학회지
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• 제13권1호
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• pp.68-74
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• 2010

충남 서산군 조간대에서 채집되어진 저서성 두족류 낙지(Octopus minor)에서 브롬계화합물(Polybrominated diphenyl ethers, PBDEs)을 측정하였다. 낙지 외투장과 내장에서의 PBDEs 농도 범위는 각각 29.6~109.3 ng/g lipid wt(평균53.7 ng/g lipid wt), 11.5~89.0 ng/g lipid wt(평균 48.0 ng/g lipid wt)로 나타났다. 낙지 내장에서의 PBDEs 농도는 살오징어 간에서의 농도에 비해 약 2.5배 가량 낮게 나타났으며, 퇴적물 및 이매패류 시료와 PBDEs 농도를 비교한 결과 낙지에서 상대적으로 낮은 농도를 나타내었다. PBDEs의 조성비를 보면 낙지 외투장에서는 BDE 206, 203/200이 각각 72.3%, 11.8%로 총 PBDEs 농도의 80%이상을 차지하여 nona-, octa-BDE가 외투장에서 PBDEs의 주요 화합물로 나타났으며, 낙지 내장 시료에서는 BDE 206, 47이 각각 49%, 18.3%로 상대적으로 높은 조성비를 나타내었다.

• 한국해양학회지
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• 제27권3호
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• pp.197-209
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• 1992

황해 남서부인 군산외해역에 서식하는 저서 다모류군집의 분포특징과 그들의 섭식 조합을 조사하기 위하여 Veen grab 채집기를 사용하여 24개 장점에서 저서동물을 채집 하였다. 총출현 다모류는 30개과에 속하는 54종이었게, 조사해역의 평균서식밀도는 약 300개체/ m$^2$였다. 주요 우점종으로는 Sternaspis scutata (10%), Notomastus sp. (10%). Lumbrineris cruzensis (9.7%), Nephtys polybrqanchia (5.6%), Praxillella affinis (5.2%) 등이었다. 주요 우점종의 출현은 퇴적상에 따라 차이를 보였는데 사질 퇴적상에서는 N. Polybranchia Prionospio pinnata, Spiophanes bombyx 등이, 니질퇴 적상에서는 S. scutata L. cruzensis, Goniada maculata 등이 나머지는 혼합퇴적물상 에서 그들의 주 출현량을 보였다. 다모류의 섭식조합은 12가지 유형으로 나타났으며, 그 중에서 BMX(표층하퇴적물식정, 운동성, 균육질 주둥이)가 출현빈도(19개 장점)나 출현량(전체의 26%)에 있어서 가장 높았다. 각 섭식조합별로 퇴적상에 대한 선호도를 보였는데, 니질퇴적상에서는 표층하퇴적물식성, 운동성 및 비촉수성 다모류가 우세하 여 섭식조합 BMX와 BMJ 등이 많이 출현하였고, 반면 사질퇴적상에서는 여과식성, 고착 성 및 촉수를 가진 FDT와 SST 등의 섭식조합이 우점하였다.

• 보존과학회지
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• 제37권4호
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• pp.312-321
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• 2021

Underwater archaeology relies heavily on photography and video image recording during surveillances and excavations like ordinary archaeological studies on land. All underwater images suffer poor image quality and distortions due to poor visibility, low contrast and blur, caused by differences in refractive indices of water and air, properties of selected lenses and shapes of viewports. In the Yellow Sea (between mainland China and the Korean peninsula), the visibility underwater is far less than 1 m, typically in the range of 30 cm to 50 cm, on even a clear day, due to very high turbidity. For photographing 1 m x 1 m grids underwater, a very wide view angle (180°) fisheye lens with an 8 mm focal length is intentionally used despite unwanted severe barrel-shaped image distortion, even with a dome port camera housing. It is very difficult to map wide underwater archaeological excavation sites by combining severely distorted images. Development of practical compensation methods for distorted underwater images acquired through the fisheye lens is strongly desired. In this study, the source of image distortion in underwater photography is investigated. We have identified the source of image distortion as the mismatching, in optical axis and focal points, between dome port housing and fisheye lens. A practical image distortion compensation method, using customized image processing software, was explored and verified using archived underwater excavation images for effectiveness in underwater archaeological applications. To minimize unusable area due to severe distortion after distortion compensation, practical underwater photography guidelines are suggested.

• 대기
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• 제31권3호
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• pp.311-326
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• 2021

To improve the predictability of high-impact weather phenomena around Seoul, where a larger number of people are densely populated, KMA conducted the intensive observation from 22 June to 20 September in 2020 over the Seoul area. During the intensive observation period (IOP), the dropsonde from NIMS Atmospheric Research Aircraft (NARA) and the radiosonde from KMA research vessel Gisang1 were observed in the Yellow Sea, while, in the land, the radiosonde observation data were collected from Icheon and Incheon. Therefore, in this study, the effects of radiosonde and dropsonde data during the IOP were investigated by Observing System Experiment (OSE) based on Korean Integrated Model (KIM). We conducted two experiments: CTL assimilated the operational fifteen kinds of observations, and EXP assimilated not only operational observation data but also intensive observation data. Verifications over the Korean Peninsula area of two experiments were performed against analysis and observation data. The results showed that the predictability of short-range forecast (1~2 day) was improved for geopotential height at middle level and temperature at lower level. In three precipitation cases, EXP improved the distribution of precipitation against CTL. In typhoon cases, the predictability of EXP for typhoon track was better than CTL, although both experiments simulated weaker intensity as compared with the observed data.

• 한국수산과학회지
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• 제51권6호
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• pp.704-713
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• 2018

Globally, the survival of many marine mammals is threatened by entanglement in fishing gear and there is also a high bycatch in Korea. This study analyzed the bycatch data of most cetacean species for Korean waters from 2011 to 2017, including the narrow-ridged finless porpoise Neophocaena asiaeorientalis, common dolphin Delphinus delphis, common minke whale Balaenoptera acutorostrata, and Pacific white-sided dolphin Lagenorhynchus obliquidens. A total of 12,262 cetaceans were captured as bycatch. In the Yellow and South Seas, the main species affected was the narrow-ridged finless porpoise, with 82.9% caught in stow nets and 11.5% captured in trawls. In the East Sea, the common minke whale, common dolphin, and Pacific white-sided dolphin were reported. The main common minke whale bycatch (43.5%) was in set nets, while common dolphins (49.0%) and Pacific white-sided dolphins (91.4%) were mainly caught in gill nets. The narrow-ridged finless porpoise, common dolphin, and common minke whale were most commonly reported in March, April, and May, while the Pacific white-sided dolphin was most frequently captured as bycatch in January and December. Each of these factors (season and gear responsible for bycatch) depended on the characteristics of the cetacean species. To conserve cetaceans, it is necessary to reduce the bycatch.

• 한국미생물·생명공학회지
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• 제48권4호
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• pp.539-546
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• 2020

A cellulolytic bacterial strain, S2-3, was isolated from sea water collected in Jeju island, Republic of Korea. The strain was aerobic and gram negative, and formed yellow colored colonies on marine agar medium. S2-3 cells were long rod-shaped, 0.5 × 0.25 ㎛ (width x length) in size, and did not have flagella. The optimal growth conditions for S2-3 were 30-35℃ and pH 6.5-7.0. Analysis of the 16S rRNA gene sequence of S2-3 revealed that it had the highest identity with those of Seonamhaeicola algicola Gy8 (97.08%), Hyunsoonleella udonensis JG48 (95.01%), and Aestuariibaculum scopimerae I-15 (94.86%). In phylogenetic analysis, S2-3 formed the same clade as S. algicola Gy8, implying that S2-3 belongs to the genus Seonamhaeicola. The major fatty acids (>10%) comprised C15:1 iso G (22.29%), C15:0 iso (17.71%), C17:0 iso 3OH (16.06%), and C15:0 iso 3OH (10.7%), resulting in quite different ratio of the component from those of S. algicola Gy8. Moreover, its biochemical characteristics, including acid production and enzyme activities, were different from those of S. algicola Gy8. Therefore, putting all these results together, we concluded S2-3 is distinct species from S. algicola Gy8, and thus named it Seonamhaeicola sp. S2-3. In liquid culture, S2-3 produced extracellular cellulases that can hydrolyze cellulose or cellooligosaccharides into cellobiose, which is a good enzyme resource that deserves further research.

• 대기
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• 제32권4호
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• pp.277-295
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• 2022

The global weather prediction model, Korean Integrated Model (KIM), has been in operation since April 2020 by the Korea Meteorological Administration. This study assessed the performance of heat waves (HWs) in Korea in 2020. Case experiments during 2018-2020 were conducted to support the reliability of assessment, and the factors which affect predictability of the HWs were analyzed. Simulated expansion and retreat of the Tibetan High and North Pacific High during the 2020 HW had a good agreement with the analysis. However, the model showed significant cold biases in the maximum surface temperature. It was found that the temperature bias was highly related to underestimation of downward shortwave radiation at surface, which was linked to cloudiness. KIM tended to overestimate nighttime clouds that delayed the dissipation of cloud in the morning, which affected the shortage of downward solar radiation. The vertical profiles of temperature and moisture showed that cold bias and trapped moisture in the lower atmosphere produce favorable conditions for cloud formation over the Yellow Sea, which affected overestimation of cloud in downwind land. Sensitivity test was performed to reduce model bias, which was done by modulating moisture mixing parameter in the boundary layer scheme. Results indicated that the daytime temperature errors were reduced by increase in surface solar irradiance with enhanced cloud dissipation. This study suggested that not only the synoptic features but also the accuracy of low-level temperature and moisture condition played an important role in predicting the maximum temperature during the HWs in medium-range forecasts.