• Title/Summary/Keyword: Yellow River school

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Numerical simulation of Hydrodynamics and water properties in the Yellow Sea. I. Climatological inter-annual variability

  • Kim, Chang-S.;Lim, Hak-Soo;Yoon, Jong-Joo;Chu, Peter-C.
    • Journal of the korean society of oceanography
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    • v.39 no.1
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    • pp.72-95
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    • 2004
  • The Yellow Sea is characterized by relatively shallow water depth, varying range of tidal action and very complex coastal geometry such as islands, bays, peninsulas, tidal flats, shoals etc. The dynamic system is controlled by tides, regional winds, river discharge, and interaction with the Kuroshio. The circulation, water mass properties and their variability in the Yellow Sea are very complicated and still far from clear understanding. In this study, an effort to improve our understanding the dynamic feature of the Yellow Sea system was conducted using numerical simulation with the ROMS model, applying climatologic forcing such as winds, heat flux and fresh water precipitation. The inter-annual variability of general circulation and thermohaline structure throughout the year has been obtained, which has been compared with observational data sets. The simulated horizontal distribution and vertical cross-sectional structures of temperature and salinity show a good agreement with the observational data indicating significantly the water masses such as Yellow Sea Warm Water, Yellow Sea Bottom Cold Water, Changjiang River Diluted Water and other sporadically observed coastal waters around the Yellow Sea. The tidal effects on circulation and dynamic features such as coastal tidal fronts and coastal mixing are predominant in the Yellow Sea. Hence the tidal effects on those dynamic features are dealt in the accompanying paper (Kim et at., 2004). The ROMS model adopts curvilinear grid with horizontal resolution of 35 km and 20 vertical grid spacing confirming to relatively realistic bottom topography. The model was initialized with the LEVITUS climatologic data and forced by the monthly mean air-sea fluxes of momentum, heat and fresh water derived from COADS. On the open boundaries, climatological temperature and salinity are nudged every 20 days for data assimilation to stabilize the modeling implementation. This study demonstrates a Yellow Sea version of Atlantic Basin experiment conducted by Haidvogel et al. (2000) experiment that the ROMS simulates the dynamic variability of temperature, salinity, and velocity fields in the ocean. However the present study has been improved to deal with the large river system, open boundary nudging process and further with combination of the tidal forcing that is a significant feature in the Yellow Sea.

A numerical study on the dispersion of the Yangtze River water in the Yellow and East China Seas

  • Park, Tea-Wook;Oh, Im-Sang
    • Journal of the korean society of oceanography
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    • v.39 no.2
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    • pp.119-135
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    • 2004
  • A three-dimensional numerical model using POM (the Princeton Ocean Model) is established in order to understand the dispersion processes of the Yangtze River water in the Yellow and East China Seas. The circulation experiments for the seas are conducted first, and then on the bases of the results the dispersion experiments for the river water are executed. For the experiments, we focus on the tide effects and wind effects on the processes. Four cases of systematic experiments are conducted. They comprise the followings: a reference case with no tide and no wind, of tide only, of wind only, and of both tide and wind. Throughout this study, monthly mean values are used for the Kuroshio Current input in the southern boundary of the model domain, for the transport through the Korea Strait, for the river discharge, for the sea surface wind, and for the heat exchange rate across the air-sea interface. From the experiments, we obtained the following results. The circulation of the seas in winter is dependent on the very strong monsoon wind as several previous studies reported. The wintertime dispersion of the Yangtze River water follows the circulation pattern flowing southward along the east coast of China due to the strong monsoon wind. Some observed salinity distributions support these calculation results. In summertime, generally, low-salinity water from the river tends to spread southward and eastward as a result of energetic vertical mixing processes due to the strong tidal current, and to spread more eastward due to the southerly wind. The tide effect for the circulation and dispersion of the river water near the river mouth is a dominant factor, but the southerly wind is still also a considerable factor. Due to both effects, two major flow directions appear near the river mouth. One of them is a northern branch flow in the northeast area of the river mouth moving eastward mainly due to the weakened southerly wind. The other is a southern branch flow directed toward the southeastern area off the river mouth mostly caused by tide and wind effects. In this case, however, the tide effect is more dominant than the wind effect. The distribution of the low salinity water follows the circulation pattern fairly well.

The establishing process of Keyongyegimunrok(經義記聞錄) by Namdang Han Wonjin and the characteristic of illustrated accounts of Heart-mind theory (남당(南塘) 한원진(韓元震)의 『경의기문록(經義記聞錄)』 성립 과정과 심성론 도설(圖說)의 특징)

  • Lee, Chang-il
    • The Journal of Korean Philosophical History
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    • no.35
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    • pp.131-164
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    • 2012
  • This paper is to make a generalization of Keyongyegimunrok(經義記聞錄) by Namdang Han Wonjin(1682~1751) whose historical positions of philosophy were contained, and to examine its established periods and the summaries of Ligi-Simseong Doseol(理氣心性圖說, illustrated Account of principle, Vital force, and Heart-mind) given in Appendix of Chap. 6. Total seventeen explanatory diagrams cover over the theory of principle and material force, theory of Heart-mind, theory of cultivation. These explanatory diagrams were produced systematically and easily to understand the pursuits of study, so-called Ho-hak(湖學), since Namdang becoming a member of the Yellow River(黃江) school. The philosophical argumentations of Namdang was usually succeeded by the orthodox stream of Ki-ho(畿湖) School transmitted from Ii, Song Si-yeol, Gwon Sang-ha. Ligi-wollyu-do(理氣源流圖), Ligi-dongjeong-do(理氣動靜圖), irwon-bunsu-do(一原分殊圖, 4 diagrams) are diagrams equivalent to Ki-ho School's ontology. As Ki-ho School's theory of Heart-mind, there are Seongjeong-hoenggan-do(性情橫看圖), Seongjeong-sugan-do(性情竪看圖), Seongjeong-chonghwoi-do(性情總會圖), Oseonghoju-do (五性互主圖), Oseongchubon-do(五性推本圖), Simseongmyohap-do (心性妙合圖), Simseongiji-do(心性二岐圖), Jungyongcheonmyeong-do(中庸天命圖), Insim dosim-do(人心道心圖), focusing on Simtongseongjeong-do(心統性情圖), and last diagram is Wihakjibang-do(爲學之方圖), which adapted from the diagram established by Ii and Song Si-yeol. The significance of Keyongyegimunrok(經義記聞錄) is comprehensive of the pursuits of the Yellow River school's studies, and provides evidence of a leading figure in Ho-hak.

Morphological and RAPD Variation of Phragmites australis along Salinity Gradient in the Wetlands of the Downstream of Yellow River, China

  • Zhang, Shuping;Wang, Renqing;Qj, Xinshan;Guo, Weihua;Song, Baimin
    • The Korean Journal of Ecology
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    • v.27 no.1
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    • pp.35-41
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    • 2004
  • Phragmites australis is the dominant and constructive species among plant communities in the wetlands of the downstream of Yellow River, China. Its morphological characters were high variable in different habitats. Studies on Morphological and RAPD variation of 15 P. australis populations from this region showed that soil salinity was the dominant ecological factor that affected the morphological characters of P. australis. The basal diameter, height, leaf length, leaf width, internode length, internode accounts, panicle length were negatively related to salinity. 194 loci were amplified by RAPD, of which 9 loci was highly negative-related to salinity, and showed a tendency to prefer the habitats with fresh water. 4 loci were positively related to the salinity, and showed a tendency to prefer the salinized habitats. Most loci were neutral to salinity. The morphological and genetic characters of BZH were special, and the speciality should not be determined by salinity. The morphological characters were affected by genetic information and environment. The morphological characters should change gradually and continuously along environmental gradient under plasticity, but should changed continuously or not in genetic control. The relevancies among quantitive characters, ecological factors and genetic variation in natural populations still will still be a focus and difficulty of ecological genetics of P. australis in the future.

Experimental study on modified low liquid limit silt for abutment backfill in bridge-embankment transition section

  • Shu-jian Wang;Yong Sun;Zhen-bao Li;Kai Xiao;Wei Cui
    • Geomechanics and Engineering
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    • v.32 no.6
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    • pp.601-613
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    • 2023
  • Low liquid limit silt, widely distributed in the middle and down reaches of Yellow River, has the disadvantages of poor grading, less clay content and poor colloidal activity. It is very easy to cause vehicle jumping at the bridge-embankment transition section when the low liquid limit silt used as the backfill at the abutment back. In this paper, a series of laboratory tests were carried out to study the physical and mechanical properties of the low liquid limit silt used as back filling. Ground granulated blast furnace slag (GGBFS) was excited by active MgO and hydrated lime to solidify silt as abutment backfill. The optimum ratio of firming agent and the compaction and mechanical properties of reinforced soil were revealed through compaction test and unconfined compressive strength (UCS) test. Scanning electron microscope (SEM) test was used to study the pore characteristics and hydration products of reinforced soil. 6% hydrated lime and alkali activated slag were used to solidify silt and fill the model of subgrade respectively. The pavement settlement regulation and soil internal stress-strain regulation of subgrade with different materials under uniformly distributed load were studied by model experiment. The effect of alkali activated slag curing agent on curing silt was verified. The research results can provide technical support for highway construction in silt area of the Yellow River alluvial plain.

Chinese Landscape Architecture and View-Shedspace - Values' Presentation of the Landscape Heritage of the Huaqing Palace Scenery Area - (지경건축여경상공간(地景建筑与景象空間) - 화청지풍경구경관문화유산적개치전시(華淸池風景區景觀文化遺産的价値展示))

  • Liu, Hui;Tong, Yuzhe
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.4
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    • pp.98-104
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    • 2010
  • Chang'an, an ancient historical city with its construction basement remains. Chinese Traditional Landscape Culture comes from the ancient civilization of the Yellow River and the environment of the central Shaanxi plain forms its ideology characteristic. Basing on the fast urbanization and growth of economies, there is a growing emphasis on Urban Landscape Cultural Heritage. The spatial pattern and traditional landscape should be protected and exhibit because it reflects the original characteristic and implied meaning of Chinese traditional landscape culture. This paper presents the case of Huaqing Palace(華淸宮) scenery area as an example; evaluate the value of its original landscape culture, showing the way of the conservation and regulation.

An Analysis of Oceanic Current Maps of the Yellow Sea and the East China Sea in Secondary School Science Textbooks (중등학교 과학교과서의 황해 및 동중국해 해류도 분석)

  • Park, Kyung-Ae;Park, Ji-Eun;Choi, Byoung-Ju;Lee, Sang-Ho;Lee, Eunil;Byun, Do-Seong;Kim, Young-Taeg
    • Journal of the Korean earth science society
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    • v.35 no.6
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    • pp.439-466
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    • 2014
  • Since the unification of the diverse oceanic current maps of the East Sea in secondary school science textbooks has recently been accomplished, there have been increasing requirements for the production of a current map of the Yellow Sea (YS) and the East China Sea (ECS). This study, as its first attempt, facilitated the prospective production process of the unified oceanic current maps in YS and ECS by analyzing the maps of scientific articles and those of the present textbooks as of 2014. First of all, the analogue current maps of the textbooks and scientific articles were digitalized to retrieve the characteristics of current maps quantitatively and to make intercomparison of the maps. The currents of both YS and ECS such as the Kuroshio Current, the Taiwan Warm Current, the Tsushima Warm Current, the Yellow Sea Warm Current, the Chinese Coastal Current, the Korea Coastal Current, and the Changjiang River Flow were selected and analyzed. We made 18 items to investigate the paths of the currents. Analyses of the oceanic current maps of secondary school science textbooks and scientific articles with respect to the selected criteria revealed that the current maps of the textbooks were considerably different from the up-to-date knowledge of the current maps acquired from the scientific articles. In addition, since the currents of YS and ECS have strong seasonality, we suggest that they should be presented with at least two current maps for summer and winter in the textbooks, which may go through active discussions among experts.

Environmental and Ecological Consequences of Submarine Groundwater Discharge in the Coastal Areas of the Korea Peninsula (한반도 연안 해역에서 해저 지하수 유출의 환경 생태학적 중요성)

  • KIM GUEBUEM;HWANG DONG-WOON;RYU JAE-WOONG;LEE YONG-WOO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.10 no.4
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    • pp.204-212
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    • 2005
  • Recognition has emerged that nutrient inputs from the submarine discharge of fresh, brackish, and marine groundwaters into the coastal ocean are comparable to the inputs via river discharge. The coastal areas of the Korea peninsula and adjacent seas exhibit particular importance in the role of submarine groundwater discharge (SGD), in terms of the magnitude of SGD and associated continental material fluxes. For example, in the southern sea of Korea, SGD transports excess nutrients into the coastal regions and thus appears to influence ecosystem changes such as the outbreak of red tides. Around volcanic island, Jeju, which is composed of high permeability rocks, the amount of SGD is higher by orders of magnitude relative to the eastern coast of North America where extensive SGD studies have been conducted. In particular, nutrient discharge through SGD exerts a significant control on coastal ecosystem changes and results in benthic eutrophication in semi-enclosed Bang-du bay, Jeju. In the entire area of the Yellow Sea, tile submarine discharge of brackish groundwater and associated nutrients are found to rival the river discharges into the Yellow Sea, including those through Yangtze River, Han River, etc. In the eastern coast of the Korea peninsula, SGD is significantly higher during summer than winter due to high hydraulic gradients and due to wide distribution of high permeability sandy zones, faults, and fractures. On the other hand, in the estuarine water, downstream construction of the dam in the Nakdong River, SGD was highest when the river discharge was lowest (but water level of the dam was highest). This suggests that even though there is no visible freshwater discharge into this estuary, the discharge of chemical species is significant through SGD. On the basis of the results obtained from the coastal areas of the Korea peninsula, SGD is considered to be an important pathway of continental contaminants influencing tidal-flat ecosystems, red tides, and coral ecology. Thus, future costal management should pay great attention to the impact of SGD on coastal pollution and eutrophication.

The Study on the State of Health and dietary Habits of boy′s and Girl′s High School Students in Seoul (서울시내 남.녀 고등학생들의 식습관과 건강상태에 관한 연구)

  • 박성효;정낙원;이효지
    • Korean journal of food and cookery science
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    • v.7 no.1
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    • pp.67-80
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    • 1991
  • This study researched the dietary habit of boy's and girl's high school students, and into low it was connected with the state of health between the group of having the right dietary habit and the group of having the wrong habit. Results were as follows: 1. The age about the object person of research was the most numerous in 79% at 16~17 years old, the average weight was $55.67\pm9.08$kg, the average height was $165.47\pm7.56$cm. 2. In the parent's school career of the object person of research, persons who graduated high school were many. The mother's educational level was lower than the father's school career. The parent's school career in the district south of a river was higher than the parent's school career in the district north of a river. And the parent's school career of cultural students was high. 3. The frequency of food intake in the district north of a river and in the district south of a river was a meaningful difference in the vegetables blended in green and yellow things (p<.01), fruit (p<.05), rice, flour, potatoes (p<.05), and so the district north of a river took less than the district south of a river. 4. The most regular diet in a day was lunch. The appetite of the students was generally good. 5. The general environment and state of health were a meaningful difference about melancholia (p<.05) in the district of north and south of river, and so melancholia in students of the north of a river was high. 6. The state of health according to regular diet was a meaningful difference, so regular student was better than irregular student in state of health, and was the same in study. 7. Eating habit correlated much to each state of health, Especially in physical health, the muscular frame correlated to fruit (p<.001), seaweeds (p<.05), fried food, jun, panbroiled food (p<.05), salty taste (p<.05), sour taste(p<.001).

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