• 제목/요약/키워드: Sea State

검색결과 826건 처리시간 0.027초

3차원 해상상태 생성을 위한 가시화 시뮬레이션 (On Visualization Simulation for Generation of Three Dimensional Sea State)

  • 손경호;배준영;김용민
    • 한국항해항만학회지
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    • 제26권4호
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    • pp.449-453
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    • 2002
  • 최근에 한국해양대학교에서는 선박조종시뮬레이터를 개발했다. 이에 따라 시뮬레이터에 해상상태를 적용하기 위해 노력중이다. 이 논문에서는 해상에서의 파의 움직임을 표현하는 수학모델과 OpenGL API를 이용하여 해상상태의 가시화 시뮬레이션 및 계산 결과의 시뮬레이터에 적용가능에 대해 논한다.

Characterization of Cytophaga-Flavobacteria Community Structure in the Bering Sea by Cluster-specific 16S rRNA Gene Amplification Analysis

  • Chen, Xihan;Zeng, Yonghui;Jiao, Nianzhi
    • Journal of Microbiology and Biotechnology
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    • 제18권2호
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    • pp.194-198
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    • 2008
  • A newly designed Cytophaga-Flavobacteria-specific 16S rRNA gene primer pair was employed to investigate the CF community structure in the Bering Sea, revealing a previously unknown and unexpected high CF diversity in this high latitude cold sea. In total, 56 clones were sequenced and 50 unique CF 16 rRNA gene fragments were obtained, clustering into 16 CF subgroups, including nine cosmopolitan subgroups, five psychrophilic subgroups, and two putatively autochthonous subgroups. The majority of sequences (82%) were closely related to uncultured CF species and could not be classified into known CF genera, indicating the presence of a large number of so-far uncultivated CF species in the Bering Sea.

원관내의 해수동결거동에 관한 실험적연구 (An Experimental Study on Sea Water Freezing Behavior in a Cooled Circular Tube)

  • 김명준
    • Journal of Advanced Marine Engineering and Technology
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    • 제22권5호
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    • pp.680-686
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    • 1998
  • In the adoption of a desalination system the most important factor is the cost of fresh water pro-duction. In general LNG is stored in a tank as a liquid state below $-162^{\circ}C$ When it is serviced however the LNG absorbs energy from a heat source and it is transformed to a high pressure gaseous state. During this process a huge amount of cold energy accumulated in cooling LNG is wasted. This wasted cold energycan be utilized to produce fresh water by using a sea water freez-ing desalination system. in order to develop a sea water freezing desalination system and to estab-lish its design technique qualitative and quantitative data regarding the freezing behavior of sea water is required in advance. The goals of this study are to reveal the freezing mechanisms of sea water in a cooled circular tube to measure the freezing rate and to investigate the freezing heat-transfer characteristics. The experimental results provide a general understanding of sea water freezing behavior in a cooled circular tube.

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Vertical Migration of Sound Scatterers in the Southern Yellow Sea in Summer

  • Lu, Lian-Gang;Liu, Jianjun;Yu, Fei;Wu, Wei;Yang, Xiaodong
    • Ocean Science Journal
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    • 제42권1호
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    • pp.1-8
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    • 2007
  • Acoustic volume backscattering strength data were collected and Conductivity Temperature Depth (CTD) measurements were conducted in the southern Yellow Sea in summer 2005 and 2006. The high temporal and vertical resolution acoustic data measured with a 307 kHz Acoustic Doppler Current Profiler (ADCP) and a 250 kHz acoustic Doppler profile (ADP) had dominant diel variation, which resulted from vertical migration of sound scatterers. Some scatterers congregating in the bottom layer in the daytime migrated upward at dusk, and migrated downward into the bottom layer at dawn. The migration speeds were estimated. More than 33 days data show that the diel migration varies with time. The feature of migration measured with ADCP and ADP is consistent to some extent with what is described in the study on vertical migration of zooplankton in the southern Yellow Sea with conventional net samples.

서해 어획대상 잠재생산량 추정을 위한 자원평가모델의 비교 분석 (Comparative analysis of stock assessment models for analyzing potential yield of fishery resources in the West Sea, Korea)

  • 최민제;김도훈;최지훈
    • 수산해양기술연구
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    • 제55권3호
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    • pp.206-216
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    • 2019
  • This study is aimed to compare stock assessment models depending on how the models fit to observed data. Process-error model, Observation-error model, and Bayesian state-space model for the Korean Western coast fisheries were applied for comparison. Analytical results show that there is the least error between the estimated CPUE and the observed CPUE with the Bayesian state-space model; consequently, results of the Bayesian state-space model are the most reliable. According to the Bayesian State-space model, potential yield of fishery resources in the West Sea of Korea is estimated to be 231,949 tons per year. However, the results show that the fishery resources of West Sea have been decreasing since 1967. In addition, the amounts of stock in 2013 are assessed to be only 36% of the stock biomass at MSY level. Therefore, policy efforts are needed to recover the fishery resources of West Sea of Korea.

A case study of gust factor characteristics for typhoon Morakat observed by distributed sites

  • Liu, Zihang;Fang, Genshen;Zhao, Lin;Cao, Shuyang;Ge, Yaojun
    • Wind and Structures
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    • 제35권1호
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    • pp.21-34
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    • 2022
  • Gust factor is an important parameter for the conversion between peak gust wind and mean wind speed used for the structural design and wind-related hazard mitigation. The gust factor of typhoon wind is observed to show a significant dispersion and some differences with large-scale weather systems, e.g., monsoons and extratropical cyclones. In this study, insitu measurement data captured by 13 meteorological towers during a strong typhoon Morakot are collected to investigate the statistical characteristics, height and wind speed dependency of the gust factor. Onshore off-sea and off-land winds are comparatively studied, respectively to characterize the underlying terrain effects on the gust factor. The theoretical method of peak factor based on Gaussian assumption is then introduced to compare the gust factor profiles observed in this study and given in some building codes and standards. The results show that the probability distributions of gust factor for both off-sea winds and off-land winds can be well described using the generalized extreme value (GEV) distribution model. Compared with the off-land winds, the off-sea gust factors are relatively smaller, and the probability distribution is more leptokurtic with longer tails. With the increase of height, especially for off-sea winds, the probability distributions of gust factor are more peaked and right-tailed. The scatters of gust factor decrease with the mean wind speed and height. AS/NZ's suggestions are nearly parallel with the measured gust factor profiles below 80m, while the fitting curve of off-sea data below 120m is more similar to AIJ, ASCE and EU.

인공해수에서 구리의 부식과 부동화 반응 (Corrosion and Passivation of Copper in Artificial Sea Water)

  • 천정균;김연규
    • 대한화학회지
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    • 제51권4호
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    • pp.305-311
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    • 2007
  • 정류상태(steady state)와 과도상태(transient state)의 Tafel 기울기, 순환 전압-전류 곡선, 임피던스 측정자료에 기초하여 인공해수에서 구리의 부식과 부동화에 대한 반응 메커니즘을 제안하였다. 구리의 산화환원 반응은 인공해수에서의 산소농도와 전극전위에 의존함을 알 수 있었다.

Characteristics of Weather and Climate over the Okhotsk Sea

  • KIM Young Seup;HAN Young Ho;CHEONG Hyeong Bin;DASHKO Nina A.;PESTEREVA Nina M.;VARLAMOV Sergey M.
    • 한국수산과학회지
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    • 제30권6호
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    • pp.974-983
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    • 1997
  • The Okhotsk Sea is unique natural object with climatic peculiarities. The climate of the Okhotsk Sea results from the general distribution of solar radiation during a year, and the characteristics of the atmospheric circulation that varies through a year: In cold half year the main pressure formations are Siberian high and Aleutian low. Asian low centered on Afghanistan dominates over the Asian continent in summer. The North-Pacific sea surface is under effect of permanent North Pacific high. The changes in their position from year to year are very significant. The anticyclonic activity over the Far Eastern Seas is one of the main factors for the formation of weather anomalies over the adjacent territories. The analysis of summer weather characteristics over the coast of Okhotsk and East Sea using the data obtained from Hydrometeorological stations during $1949\~1990$ showed that, to a great extent, distribution of the air temperature depends on thermal state of the Okhotsk Sea and atmospheric circulation over it. We show some relations between weather characteristics and the intensity of atmospheric action center for the North Pacific high in summer when its ridge propagates to Okhotsk Sea. Correlation coefficients between air pressure over the Okhotsk Sea and air temperature for the coastal areas reach up to 0.7. Analysis of the spatial-temporal distribution of main meteorological values over the Okhotsk Sea such as air pressure, and air temperature are also performed.

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Features of Malignancy Prevalence among Children in the Aral Sea Region

  • Mamyrbayev, Arstan;Dyussembayeva, Nailya;Ibrayeva, Lyazzat;Satenova, Zhanna;Tulyayeva, Anara;Kireyeva, Nurgul;Zholmukhamedova, Dinara;Rybalkina, Dina;Yeleuov, Galymzhan;Yeleuov, Almasbek
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권12호
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    • pp.5217-5221
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    • 2016
  • Objective: A study of primary cancer morbidity among children and subsequent calculation of average annual incidence were carried out for boys and girls, and young men and women in Kazakhstan. Methods: The investigated population lived in three areas of the Aral Sea region: designated catastrophe (Aral, Kazalt, Shalkar regions), crisis (Zhalagash, Karmakshy, Shiely regions), pre-crisis (Irgiz, Arys, Ulytau regions). Zhanaarka region of Karaganda oblast was applied as a control. Parameters were retrospective analyzed for the 10 years from 2004 to 2013. Result: The results indicate that indices of children cancer morbidity were slightly higher in the Aral Sea region than in the control district, but they were comparable with similar data from studies in other regions. In all areas of the Aral Sea region, except for Ulytau, primary cancer morbidity exceeded the control level by 1.3-2.7 times (4.7%000). Hematological malignancies, including solid tumors - tumors of musculoskeletal system and skin, digestive system, brain and central nervous system predominated. Stress levels in zones of the Aral Sea region were slightly higher in the crisis zone than in the catastrophe zone that can be explained by the phenomenon of wave-like dynamics of disease growth risk. Gender differences in characteristics of malignancy formation were not more pronounced in the studied region. Conclusion: Indices of children cancer are slightly higher in the Aral Sea region than in the control area of Kazakhstan, but they are comparable to results for other regions.

Simulation of the Temperature and Salinity Along $36^{\circ}N$ in the Yellow Sea with a Wave-Current Coupled Model

  • Qiao, Fangli;Ma, Ji-An;Yang, Yong-Zeng;Yuan, Yeli
    • Journal of the korean society of oceanography
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    • 제39권1호
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    • pp.35-45
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    • 2004
  • Based on the MASNUM wave-current coupled model, the temperature and salinity structures along $36^{\circ}N$ in the Yellow Sea are simulated and compared with observations. Both the position and strength of the simulated thermocline are similar to data analysis. The wave-induced mixing is strongest in winter and plays a key role in the formation of the upper mixed layer in spring and summer. Numerical experiments suggest that in the coastal area, wave-induced mixing and tidal mixing control the vertical structure of temperature and salinity.