• 제목/요약/키워드: ocean science & technology

검색결과 3,850건 처리시간 0.038초

Seasonal Variation in Fatty Acid Composition in Female Pen Shell (Atrina Pectinata)

  • Baik Sung-Hyun;Kim Kang-Jeon;Choo Jong-Jae;Choe Sun-Nam;Chung Ee-Yung;Park Kwan Ha
    • Fisheries and Aquatic Sciences
    • /
    • 제4권4호
    • /
    • pp.261-264
    • /
    • 2001
  • Seasonal variation in fatty acid profiles was examined in the visceral mass and the posterior adductor muscle of the female pen shell, Atrina pectinata. Total percentages of saturated fatty acids were similar between the two organs, and there was not a prominent seasonal change in both tissues. While the percentages of highly unsaturated fatty acids (HUFAs) in the visceral mass were higher than those in the posterior adductor muscle, monounsaturated fatty acids (MUFAs) were high in the posterior adductor muscle. HUFA contents, especially in $20: 5\omega3$, $22: 5\omega3$ and $22: 6\omega3$, markedly decreased in September in the visceral mass, and this decrease was associated with a corresponding total MUFAs in the same organ. A similar pattern of change in September was noted in the posterior adductor muscle MUFAs and HUFAs. These results indicate that $20:\omega3$ and $22:\omega3$ HUFA changes in the visceral mass and posterior adductor muscle reflect the reproductive stages in pen shell.

  • PDF

Cloud Task Scheduling Based on Proximal Policy Optimization Algorithm for Lowering Energy Consumption of Data Center

  • Yang, Yongquan;He, Cuihua;Yin, Bo;Wei, Zhiqiang;Hong, Bowei
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권6호
    • /
    • pp.1877-1891
    • /
    • 2022
  • As a part of cloud computing technology, algorithms for cloud task scheduling place an important influence on the area of cloud computing in data centers. In our earlier work, we proposed DeepEnergyJS, which was designed based on the original version of the policy gradient and reinforcement learning algorithm. We verified its effectiveness through simulation experiments. In this study, we used the Proximal Policy Optimization (PPO) algorithm to update DeepEnergyJS to DeepEnergyJSV2.0. First, we verify the convergence of the PPO algorithm on the dataset of Alibaba Cluster Data V2018. Then we contrast it with reinforcement learning algorithm in terms of convergence rate, converged value, and stability. The results indicate that PPO performed better in training and test data sets compared with reinforcement learning algorithm, as well as other general heuristic algorithms, such as First Fit, Random, and Tetris. DeepEnergyJSV2.0 achieves better energy efficiency than DeepEnergyJS by about 7.814%.

Identification of Skeletal Deformities in Far Eastern Catfish, Silurus asotus under Indoor Aquaculture Condition

  • Yang, Won Seok;Gil, Hyun Woo;Yoo, Gwang Yeol;Park, In-Seok
    • 한국발생생물학회지:발생과생식
    • /
    • 제19권3호
    • /
    • pp.153-161
    • /
    • 2015
  • For the 2 years of farming, at the indoor circulating aquaculture system, four kinds of skeletal deformities were found among 60 Far Eastern catfish, Silurus asotus. Deformities saw jawbone's luxation, abnormality of upper lip and malocclusion. Spinal deformity was most fatal deformities with low weight and small length. Jawbone's luxation had 1 maxilla and 2 mandibles. Abnormality of upper lip had just lip was back over. Malocclusion's left maxilla and right maxilla were not balanced. This experiment was any deformities in this species through the deformity can grasp how it affects.

국가 해양보호구역 지정규모에 관한 국제비교 연구 (Research of International Comparison about Ranging the Marines Protected Areas (MPA))

  • 장덕희;이창열;조은영
    • Ocean and Polar Research
    • /
    • 제44권4호
    • /
    • pp.339-353
    • /
    • 2022
  • The purpose of this research is to conduct an empirical analysis regarding Korea's 'Marine Protected Areas (MPA)' from an international comparative perspective. The authors would like to present the policy direction of marine protected areas based on the result of the research. The result of this study can be summarized in the following manner: First, the total designated size of marine protected areas in Korea is very small compared to the sizes of other OECD nations . Second, while some nations have expanded the extent of marine protected areas in accordance with international agreements and criteria, Korea has not done so. Accordingly, we propose the designated dimensions of marine protected areas should be constantly expanded to keep pace with international trends.

Evaluation of a Visible Implant Fluorescent Elastomer Tag in the Soft-shelled Turtle, Pelodiscus sinensis

  • Park, Min-Ouk;Seol, Dong-Won;Im, Soo-Yeon;Hur, Woo-June;Park, In-Seok
    • Fisheries and Aquatic Sciences
    • /
    • 제10권4호
    • /
    • pp.226-229
    • /
    • 2007
  • Survival, tag retention and tag readability were compared among the control and three treatment groups of soft-shelled turtles, Pelodiscus sinensis Crother, 2000 (mean body $weight{\pm}SD$: $182.6{\pm}13.7\;g$), marked with visible implant fluorescent elastomer (VIFE) tags for 16 months. Mortality 4 to 16 months after tagging was attributed to collection and handling stress rather than to the tagging itself. Tags applied to the web surface between the fourth and fifth dactyl of the hindfoot appeared to have the highest retention rates, while adipose eyelid tagging had high tag readability but a high loss rate. We conclude that in soft-shelled turtles, the most suitable region for VIFE tagging is on the web surface between the fourth and fifth dactyls of the hindfoot.

미국 해양기반기후해법 법안(Ocean Based Climate Solution Act, OBCSA)의 검토와 국내 해양기후변화 법제에 대한 시사점 (A Review of a Bill on the Ocean-Based Climate Solution Act (OBCSA) in the U.S and Implications for the Ocean Climate Change-Related Legal System in Korea)

  • 윤소라;이문숙
    • Ocean and Polar Research
    • /
    • 제45권2호
    • /
    • pp.71-87
    • /
    • 2023
  • Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

Evaluation of visible fluorescent elastomer tags implanted in marine medaka, Oryzias dancena

  • Im, Jae Hyun;Gil, Hyun Woo;Park, In-Seok;Choi, Cheol Young;Lee, Tae Ho;Yoo, Kwang Yeol;Kim, Chi Hong;Kim, Bong Seok
    • Fisheries and Aquatic Sciences
    • /
    • 제20권9호
    • /
    • pp.21.1-21.10
    • /
    • 2017
  • The aim of this study was to assess visible implant fluorescent elastomer (VIE) tagging and stress response in marine medaka, Oryzias dancena. The experimental fish were anesthetized individually and marked with red, yellow, or green elastomer at each of the following three body locations: (1) the abdomen, (2) the back, and (3) the caudal vasculature. During 12 months, the accumulated survival rates of fish in the experimental treatments were not different among red, yellow, and green elastomers. The experimental fish retained > 85% of the tags injected in the back, > 70% of the tags injected in the caudal vasculature, and > 60% of the tags injected in the abdomen (P < 0.05). An important observation was that the abdomen site was associated with poor tag retention. For all injected sites, the red and green tags were able to be detected more easily than the yellow tags when observed under both visible and UV lights. Tag readability was lower for the abdomen site than for the other sites (back and caudal vasculature). Thus, VIE tags were easy to apply to marine medaka (< 1 min per fish) and were readily visible when viewed under UV light.

비동기식 센서 융합을 이용한 수중 구조물 부착형 수중 위치 인식 시스템 개발 (Development of Underwater Positioning System using Asynchronous Sensors Fusion for Underwater Construction Structures)

  • 오지윤;신창주;백승재;장인성;정상기;서정민;이화준;최재호;원성규
    • 한국산학기술학회논문지
    • /
    • 제22권3호
    • /
    • pp.352-361
    • /
    • 2021
  • 한국해양과학기술원에서는 수중 공사용 구조물에 적용할 수 있는 수중 위치 인식 기술을 개발하고 있다. 정밀한 위치 인식을 위해 관성 항법을 기반으로 한 확장 칼만 필터를 사용하였으며, 비동기화 된 센서들의 데이터를 알고리즘 보정 단계에 적용하기 위하여 내부의 관측 행렬을 데이터에 따라 구분하여 업데이트 하였다. 수중 공사 환경, 설치 위치, 시스템 운용 편의성 등을 종합적으로 고려하여 수중 공사 구조물 하부에 붙여야 신호를 획득할 수 있는 Doppler velocity logger(DVL)는 설치 및 회수가 어렵기 때문에 이를 배제한 수중 공사 구조물 부착용 수중 위치 인식 복합 시험체를 제작하였으며 수조 환경에서 수중 위치 인식 성능 시험을 수행하였다. Ultra short-base line(USBL)로 측정된 수중 위치, 위치 벡터만 보정된 추정 위치, 그리고 위치와 속도 벡터를 보정한 추정 위치 결과를 원형 공산 오차(CEP)를 이용하여 비교 및 평가하였다. 그 결과 USBL 단독 위치 추정 CEP 0.02 m, 위치 벡터만 보정한 추정 위치 CEP 3.76 m., 위치 및 속도 벡터를 보정한 추정 위치 CEP 0.06 m로 평가되었다. 본 연구를 통해 DVL이 미적용된 비동기식 센서들을 이용하여 안정적인 수중 위치를 추정할 수 있음을 확인하였다.

넙치에서 lincomycin 근육투여에 따른 휴약기간 도출 및 병원성 그람음성 세균에 대한 약효 평가 (Withdrawal time study of lincomycin administered intramuscularly to olive flounder Paralichthys olivaceus, and in vitro efficacy evaluation against Gram-negative bacterial pathogens)

  • 정은하;김근택;신동훈;배준성;이강욱;이채원;양찬영;김아름;이지훈;박수진;박관하
    • 한국어병학회지
    • /
    • 제35권2호
    • /
    • pp.195-203
    • /
    • 2022
  • 본 연구는 lincomycin (LM)의 근육투여에 따른 저수온(13℃)에서의 잔류 특성 및 넙치에서 병원성 세균으로 발견되는 그람음성 세균에서의 시험관 내 in vitro 약효를 평가하기 위하여 수행하였다. LM을 10, 20 및 40 mg/kg의 용량으로 단회 투여하였을 때, 근육내 농도가 잔류허용기준인 0.1 mg/kg 이하로 감소하는 기간은 각각 32일, 33일 및 55일로 평가되었다. 또한, 현장 분리 균주 그람음성 세균인 Edwardsiella piscida 및 Vibrio harveyi에 대하여 LM의 minimal inhibitory concentration (MIC)로 평가된 in vitro 약효는 각각 >256 ㎍/mL 및 32 ㎍/mL을 나타냈다. 연구 결과, 넙치 양식장에서 사용되는 LM의 임상용량인 10 mg/kg을 고려하였을 때의 휴약기간을 30일 이상으로 설정하면 합리적일 것으로 판단된다. 또한 LM이 넙치 연쇄상구균증 치료 목적으로 투여될 때 그 동시에 감염된 그람음성 세균에는 약효가 발휘되지 않을 것으로 추정한다.

선박운항 분야에서의 해양위성 활용 연구 방안 (Utilization of Ocean Satellites in the field of Ship Operation)

  • 이형탁;한희정;박영제;양현;조익순
    • 한국항해항만학회:학술대회논문집
    • /
    • 한국항해항만학회 2023년도 춘계학술대회
    • /
    • pp.158-159
    • /
    • 2023
  • 해양위성의 발달과 첨단화로 우리나라 주변 해역의 광역적인 관리가 가능해졌다. 특히 선박운항 분야에서도 인공지능 및 빅데이터에 기반한 자율운항 기술개발이 이루어짐에 따라, 해양위성자료를 통한 분석 및 관측의 필요성이 있다. 해양위성자료에 선박운항분야를 접목할 수 있는 연구는 해양위성 기반 선박탐지, 해양 환경/기상 예측을 활용한 선박운항 보조 등이 있다.

  • PDF