• 제목/요약/키워드: the East

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동해 북서해역의 표층해황 특성 (On the Characteristics of the Oceanic Condition in the Surface Layer of the Northwestern East Sea (Japan Sea))

  • 김철호
    • 한국해안해양공학회지
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    • 제8권2호
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    • pp.215-220
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    • 1996
  • 동한만을 중심으로 한 동해 북서해역의 계절별 및 연별 표층해황 특성을 고찰하였다. 동한만의 계절별 해황은 춘계에 동한난류수의 세력이 우세하다가 하리에 북한한류의 강화와 더불어 냉수역이 발달하는 형과, 봄부터 냉수의 세력이 탁월하다가 여름이 되면서 동한난류수의 영향을 받는 형의 두가지 유형을 보인다. 경년변동 특성도 동한난류와 북한한류간의 흐름의 상대적 세기와 유로에 따라 4가지 유형으로 분류된다. 각각의 경우, 동한만 부근에는 대ㆍ소규모의 저기압성 냉수과 혹은 고기압성 난수과가 발달하는 것이 한 특징이다.

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Ocean Response to Typhoon Rusa in the South Sea of Korea and in the East China Sea

  • Lee, Dong-Kyu;Niiler, Peter
    • Journal of the korean society of oceanography
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    • 제38권2호
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    • pp.60-67
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    • 2003
  • Typhoon Rusa passed over the East China Sea and crossed over the Korea Peninsula on August 31, 2002. The core of the typhoon passed directly over a data buoy mooring site at ($127^{\circ}45'E,\;34^{\circ}25'\;N$) and several ARGOS-tracked drifters capable of measuring salinity. Peak hourly mean wind speed reached 28 m/s at the mooring site and wind pattern in the East China Sea changed from southerly wind to northwesterly wind after the typhoon passage. Two or three days before the typhoon tile drifter displacement changed significantly and the region-wide circulation pattern changed from a northeastward current to a westward current one week after the typhoon had passed. The surface water in the East China Sea was cooled to about $4^{\circ}C$ under the typhoon core and a general cooling occurred in most of the East China Sea with the exception of the Chinese coast. The salinity as observed by the drifters in the East China Sea increased about 2 psu but the near-shore water along the Korean coast observed by the mooring was freshened about 3 psu. The freshening of near-shore water was caused by an intrusion of off-shore water rather than local freshening by typhoon precipitation.

Comparison of RIAMOM and MOM in Modeling the East Sea/Japan Sea Circulation

  • Lee, Ho-Jin;Yoon, Jong-Hwan;Kawamura, Hideyuki;Kang, Hyoun-Woo
    • Ocean and Polar Research
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    • 제25권3호
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    • pp.287-302
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    • 2003
  • The seasonal variations in the circulation of the water mass in the East Sea/Japan Sea have been simulated using a free surface primitive ocean model, RIAMOM (RIAM Ocean Model), comparing the results from GFDL-MOM1 (Geophysical Fluid Dynamics Laboratory Modular Ocean Model, version 1.1, hereafter MOM) with the GDEM (Generalized Digital Environmental Model) data. Both models appear to successfully reproduce the distinct features of circulation in the East Sea/Japan Sea, such as the NB (Nearshore Branch) flowing along the Japanese coast, the EKWC (East Korean Warm Current) flowing northward along the Korean coast, and the NKCC/LCC (North Korean Cold Current/Liman Cold Current) flowing southwestward along Korean/Russian coast. RIAMOM has shown better performance, compared to MOM, in terms of the realistic simulation of the flow field in the East Sea/Japan Sea; RIAMOM has produced more rectified flows on the coastal region, for example, the narrower and stronger NKCC/LCC than MOM has. There is however obvious differences between the model results and the GDEM data in terms of the calculation of the water mass; both models have shown a tendency to overpredict temperature and underpredict salinity below 50m; more diffusive forms of thermocline and halocline have been simulated than noted in GDEM data.

Interaction among the East Asian Summer and Winter Monsoons, the Tropical Western Pacific and ENSO Cycle

  • Huang, Rong-Hui;Lu, Ri-Yu;Chen, Wen;Chen, Ji-Rong
    • 대기
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    • 제13권2호
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    • pp.47-68
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    • 2003
  • Recent advances in the studies on the interaction between Asian monsoon and ENSO cycle are reviewed in this paper. Through the recent studies, the East Asian summer monsoon circulation system and the East Asian climate system have proposed. Moreover, different responses of the (winter and summer) monsoon circulation and summer rainfall anomalies in East Asia to ENSO cycle during its different stages have been understood further. Recently, the studies on the dynamical effect of East Asian monsoon on the thermal variability of the tropical western Pacific and ENSO cycle have been greatly advanced. These studies demonstrated further that ENSO cycle originates from the tropical western Pacific, and pointed out that the dynamical effect of East Asian winter and summer monsoons on ENSO cycle may be through the atmospheric circulation and zonal wind anomalies over the tropical western Pacific, which can excite the oceanic Kelvin wave and Rossby waves in the equatorial Pacific. Besides, the scientific problems in the interaction between Asian monsoon and ENSO cycle, which should be studied further in the near future, are also pointed out in this paper.

Strengthened Madden-Julian Oscillation Variability improved the 2020 Summer Rainfall Prediction in East Asia

  • Jieun Wie;Semin Yun;Jinhee Kang;Sang-Min Lee;Johan Lee;Baek-Jo Kim;Byung-Kwon Moon
    • 한국지구과학회지
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    • 제44권3호
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    • pp.185-195
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    • 2023
  • The prolonged and heavy East Asian summer precipitation in 2020 may have been caused by an enhanced Madden-Julian Oscillation (MJO), which requires evaluation using forecast models. We examined the performance of GloSea6, an operational forecast model, in predicting the East Asian summer precipitation during July 2020, and investigated the role of MJO in the extreme rainfall event. Two experiments, CON and EXP, were conducted using different convection schemes, 6A and 5A, respectively to simulate various aspects of MJO. The EXP runs yielded stronger forecasts of East Asian precipitation for July 2020 than the CON runs, probably due to the prominent MJO realization in the former experiment. The stronger MJO created stronger moist southerly winds associated with the western North Pacific subtropical high, which led to increased precipitation. The strengthening of the MJO was found to improve the prediction accuracy of East Asian summer precipitation. However, it is important to note that this study does not discuss the impact of changes in the convection scheme on the modulation of MJO. Further research is needed to understand other factors that could strengthen the MJO and improve the forecast.

Rational Leadership for the Middle East: A Multiple Competencies Model

  • ALDULAIMI, Saeed Hameed
    • The Journal of Asian Finance, Economics and Business
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    • 제8권4호
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    • pp.687-697
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    • 2021
  • This study aims to address the prevailing skepticism that conventional leadership models are not effective in the Middle East. With the same logic, selecting leaders is a confusing task in the Middle East due to the haphazardness surrounding this task and the lack of clarity of appropriate selection criteria. This study employs samples of leadership theories and frameworks that were scrutinized to classify specific leadership dimensions. The triangular model stemmed from the previous studies that addressed Leadership in general and the Leadership model for the Middle East. With the use of the literature review methodologies and historical analysis, the leadership model's description will be demonstrated. The results revealed that there are various dimensions of Leadership, especially concerning the Middle East's organizational environment. The findings of this study suggested a new model which assists in clarifying the issue by setting a group of 10 personality traits with eight behavioral skills and social status. Implications of this study enable making Leadership easier in practice. Furthermore, this will enable recognition of Leadership according to specific criteria, which will help make greater equality and empowerment at all levels of the system. This research localizes Leadership and paves the way to automate leaders' selection process with a guarantee of fairness among candidates.

한국 연안산 지충이(Sargassum thunbergii)의 생태 (Ecology of Sargassum thunbergii along the Korean Coast)

  • 서지오;박형섭;정원기;김남길
    • 한국수산과학회지
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    • 제56권5호
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    • pp.684-690
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    • 2023
  • This study was conducted bimonthly from February to December 2021 to reveal the ecology of Sargassum thunbergii in the intertidal zone along the coasts of Korea. Separate surveys on the period of embryo formation were conducted from February 2021 to December 2022. The growth of S. thunbergii began to increase in February, reached a maximum in June, and was at a minimum in October. Air vesicles were formed from February to June, April to August, and February to August on the east, west, and south coasts, respectively. Receptacles were observed from April to June on the east coast, but from April to August on the west and south coasts. The earliest release of embryos was observed in late May 2022 on the south coast, followed by early June on the east and west coasts. The average size of leaves, stems, and air vesicles was maximum on the east coast and minimum on the west coast, whereas leaf and internode intervals were maximum on the west coast and minimum on the east coast. Plant length, biomass, and the number of branches showed maximum values in the south coast and minimum values in the east coast.

Shallow Water Tides in the Seas around Korea

  • Kantha, Lakshmi H.;Bang, In-Kweon;Choi, Jei-Kook;Suk, Moon-Sik
    • Journal of the korean society of oceanography
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    • 제31권3호
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    • pp.123-133
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    • 1996
  • We describe here the shallow water tides in the seas around Korea, obtained from a nonlinear barotropic model of tides in a domain encompassing the Yellow Sea, the East China Sea and the East Sea (Sea of Japan). As expected, the shallow water tides are large in the shallow marginal areas around the Yellow Sea, with the M4 tide reaching amplitudes as high as 10 cm near the Korean coast, and quite small in the East Sea. However, we also find that the regions east of the Yangtze River ($126^{\circ}E,$ $30^{\circ}N$) in the East China Sea also sustain large shallow water tides, with $M_{4}$, amplitudes reaching 5 cm. Such large shallow water tides are an important component of altimeter-measured sea levels and should not be ignored in any altimetric analyses of the Yellow Sea and the East China Sea. This study also highlights the desirability of very high resolution models to derive accurate shallow water tides in coastal regions.

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Study on transient performance of tilting-pad thrust bearings in nuclear pump considering fluid-structure interaction

  • Qiang Li;Bin Li;Xiuwei Li;Quntao Xie;Qinglei Liu;Weiwei Xu
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2325-2334
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    • 2023
  • To study the lubrication performance of tilting-pad thrust bearing (TPTBs) during start-up in nuclear pump, a hydrodynamic lubrication model of TPTBs was established based on the computational fluid dynamics (CFD) method and the fluid-structure interaction (FSI) technique. Further, a mesh motion algorithm for the transient calculation of thrust bearings was developed based on the user defined function (UDF). The result demonstrated that minimum film thickness increases first and then decreases with the rotational speed under start-up condition. The influence of pad tilt on minimum film thickness is greater than that of collar movement at low speed, and the establishment of dynamic pressure mainly depends on pad tilt and minimum film thickness increases. As the increase of rotational speed, the influence of pad tilt was abated, where the influence of the moving of the collar dominated gradually, and minimum film thickness decreases. For TPTBs, the circumferential angle of the pad is always greater than the radial angle. When the rotational speed is constant, the change rate of radial angle is greater than that of circumferential angle with the increase of loading forces. This study can provide reference for improving bearing wear resistance.

동(東)아프리카 지역(地域)에서 광범위(廣範圍)하게 착용(着用)하는 Kanga개념(槪念) 연구(硏究) (A Study on Kanga Fundanental Notion of Apparel Widely Throughout East Africa)

  • 강은숙
    • 패션비즈니스
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    • 제8권4호
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    • pp.104-116
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    • 2004
  • Kanga is a type of cotton clothes with splendid patterns that East African women throw on their bodies. It first appeared in the East African shores in the mid-nineteenth century. A new style of squared handkerchiefs brought to Africa by Portuguese merchants for the first time was referred as to leso of which early designs were in a basic form of white dots on dark background. Consumers called such material by kanga as they began mentioning its craftiness and comparing its elegant nature to a sociable red rooster and graceful feathers. From the early 1990s, Swahili characters have been embroidered in designs of kanga, mainly consisted of proverbs. Kenya's kanga products are widely known and well represented whereas Tanzania makes the best use of it for political and social events. Fascinating and practical kanga has established its position as an essential part of East African cultures that is being well received as a fashion style there in these days.