• Title/Summary/Keyword: dominant period

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Analysis of Runoff Characteristics in the Geum River Basin using Watershed Management Model (유역관리모형을 이용한 금강유역 유출특성 해석)

  • Ryoo, Kyong-Sik;Hwang, Man-Ha;Maeng, Seung-Jin;Lee, Sang-Jin
    • Journal of Korean Society on Water Environment
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    • v.23 no.4
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    • pp.527-534
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    • 2007
  • To operate scientifical and integrated management of water resources, it needs to identify clearly the quantitative variation and moving pathway of water resources in a basin. Moreover, it needs to also estimate more precisely the amount of runoff generating from the precipitation. Thus, in this study, to carry out more reliable hydrologic analyses, the runoff characteristics according to detailed runoff components and water balance in a basin are analyzed. As a result of yearly water balance analyses, during the period of drought year, the loss is bigger than that of 6-year mean loss and the return flow of groundwater is the most dominant component of runoff. During the period of flood year, the loss is smaller about 4% than that of 6-year mean loss and the subsurface water is the most dominant component of runoff. The loss due to the interception and evapotranspiration for 6-year mean loss is about 53% of the total rainfall, the mean runoff ratio is about 27% and the baseflow is about 22%.

Morphological Transformation of Building Blocks of Apartment Complexes in Busan (부산 아파트 단지의 주동 평면형태의 변화 특성에 관한 연구)

  • Lee, Sangjin;Park, SoHyun
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.8
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    • pp.3-14
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    • 2019
  • The research is to track the morphological transformation of residential towers of apartment complexes in Busan. Though apartment is one of the most important components in Korean society, it has not drawn enough attention from academia as well as the public, especially regarding its shape. In result, its morphological change has barely been recognized. Instead, negative, but superficial, evaluation has become dominant tendency to deal with the shape of apartment tower. There are numerous 'partial' evidences to inform the morphological change of apartment plan type, and understanding the change is critical since morphological resultant reflects culture, politics, economy of a society. The research has been done on the 261 apartment complexes built through 2016 in Busan. The analysis shows that $I^0$ type, to represent 'typical boring architectural shape' of Korean apartments, has been dominant until the year 2000. However, its portion has become drastically decreased since the mid-2000. Composite plan type, the geometrical precedents of which had never been existent, emerged in the mid-2000, and this phenomenon may symbolize the change of morphology of apartment. When tower plan types are grouped together according to geometrical shape, three types, I-type, L-type and Y-type, take the most of residential towers, explaining 97% of the total. As expected, I-type is the most dominant, but its influence has decreased as time passes. Y-type might become one of the most important type in the period V. L-type has become the leading type in the Period VI to exceed I-type by 12 percent.

Seasonal Variation in the Species Composition of Larval Fish Assemblages in the Coastal Waters off Gadeok-do, South Sea, Korea (한국 남해 가덕도 인근해역에 출현하는 자어의 종조성과 계절변동)

  • Eun Kyung Lee
    • Korean Journal of Ichthyology
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    • v.35 no.4
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    • pp.294-304
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    • 2023
  • Seasonal variations in the community structure of larval fish assemblage in the coastal waters off Gadeok-do were investigated in May, August and November of 2019, and February in 2020. During the study period, a total of 85 larvae species belonging to 45 families were collected. The dominant species were Engraulis japonica, Gobiidae sp., Clupea pallasii, Decapterus maruadsi, and Callionymidae sp.. These five species accounted for 84.1% of the total number of larvae during the survey period. E. japonica, Gobiidae sp., D. maruadsi, and Callionymidae sp. were the dominant species in the summer, while C. pallasii was the dominant species in the winter. The Species Diversity Index was highest in the summer and lower in the fall and winter months, with the lowest values in the spring. As a result of cluster analysis using the number of individual larval fish showed that they are divided into four seasonal groups. In particular, due to seasonal changes in water temperature, an appropriate growth environment was formed in the summer, and an appropriate hatching water temperature for winter spawning fish species was formed in winter, reflecting the seasonal characteristics of the larval fish community.

Analysis of Productivity in Rice Plant - (III) Dynamic Change of Canopy Structure - (벼의 생산력 분석 - (III) 군락구조의 동적변화 -)

  • Park, Hoon;Park, Young-Sun
    • Applied Biological Chemistry
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    • v.15 no.1
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    • pp.41-47
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    • 1972
  • Comparative study on dynamic change of canopy structure during ripening period were carried out by using newly bred high yield rice cultivar (IR 667-Suwon 213) and a commercial variety, Jinhung in relation to nitrogen nutrition. The results were as follows. 1. Canopy structure pattern (vertical distribution of dry matter density at heading)was vertical type for Jinhung and horizontal type for IR 667. 2. The vertical distribution pattern of leaf area density (or weight) in the canopy was central dominant type for IR 667 while apical dominant type for Jinhung. 3. Canopy conservation pattern and percent distribution pattern of leaf area density followed the vertical distribution pattern of leaf area density. 4. Canopy persistence was weaker in IR 667, thus they have smaller canopy conservation ratio indicating faster senescence. 5. Slow supply of nitrogen (sulfur coated urea) showed a trend to change the apical dominant pattern into the central dominant pattern by the conservation of central portion, and it-resulted in higher yield though nitrogen nutrition did little affect canopy pattern. 6. The central and apical dominant pattern appeared to be well matched to the upper leaf-dependent type and the lower leaf-dependent type of grain yield, respectively.

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The Influence of Oceanic Conditions on the Occurrence of Cochlodinium polykrikoides Blooms in the East Sea (동해안의 Cochlodinium polykrikoides 적조 발생에 미치는 해황의 특성)

  • Shim, Jeong-Min;Hwang, Jae-Dong;Jeong, Chang-Su;Lee, Yong-Hwa;Jeon, Kyeong-Am;Kwon, Kee-Young
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1385-1395
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    • 2010
  • Harmful dinoflagellate Cochlodinium polykrikoides blooms have been frequently occurred in coastal areas of the East Sea since 1995. We compared the oceanic conditions in years 1995, 2001 and 2003 when the C. polykrikoides bloom was strong, and in years 1998 and 2004 when the C. polykrikoides bloom was not appeared. We studied temporal and spatial variation of upwelling and geostrophic currents on the western channel of Korean Strait, an entrance of the East Sea. The period and occurrence area of C. polykrikoides bloom was depended on variation of upwelling in summer. In the distributions of geostrophic current, southward current was dominant near the coast in August, 1998 and 2000. Whereas northward current was dominant near and off the coast in August, 1995 and 2003 which the C. polykrikoides bloom was strong. When compared dominant phytoplankton of the coastal areas in each year, Kuroshio indicator species Proboscia alata and Chaetoceros affine were dominant, respectively, in 2001 and 2003 at every stations. However, the dominant species was variable at each coastal area in 1998 and 2000. In 2003, the abundance of Sagitta elegans which is known as the cold water indicator was low, but the abundance of S. enflata, warm water indicator, was very high in Gangneung compared to Sokcho. It seemed that the distribution of S. elegans is restricted by strong warm water current. In conclusion, it was estimated that the distribution of C. polykrikoides bloom in the coastal area of the East Sea was closely related with the strength of East Korea Warm Current and upwelling.

Seasonal Variation of Phytoplankton and Zooplankton Communities in the Coastal Waters off Tongyeong in Korea

  • Lee, Jin-Hwan;Chae, Jin-Ho;Kim, Won-Rok;Jung, Seung-Won;Kim, Jong-Man
    • Ocean and Polar Research
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    • v.23 no.3
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    • pp.245-253
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    • 2001
  • To investigate the community structures and the their seasonal variation of phytoplankton and zooplankton, a study was conducted at 6 selected stations during the period from April 1999 to October 2000 in the marine ranching ground off Tongyeong. One hundred ninety species of phytoplankton were identified, including 146 diatoms, 38 dinoflagellates, 4 silicoflagellates and 2 euglenophytes. Phytoplankton standing crops varied extensively by months and stations, ranging from $3.0{\times}10^4\;cells/l\;to\;1.0{\times}10^6\;cells/l.$. The dominant species varied from the vertical distribution as well as seasonal changes. In April and July 1999, Skeletonema costatum and Ceratium fusus were predominant in both the surface and the bottom water columns. Leptocylindrus danicus was the dominant species in April and June 2000, and Thalassiosira spp. were also predominant in bottom waters in June 2000. Pseudonitzschia pungens and Chaetoceros spp. were the dominant species at both surface and near bottom waters in August and October 2000, respectively. Zooplankton abundance was comparatively high in April and July in 1999, and April, June, and October in 2000, but extremely low in November 1999. The density of dominant zooplankton was higher in 2000 than in 1999. Copepods were the most predominant group except for July 1999 when the bivalve larvae showed extremely high abundance. Acartia omorii and Oithona similis were the dominant or subdominant copepod species mainly in April 2000, and June/July, while O. davisae and O. plumifera had peaks in August and October 2000. Corycaeus affinis and Paracalanus sp. also showed higher peaks in April and June (or July), even though they occurred in all sampling time. Centropages abdominalis occurred abundantly only in April 1999. Oikopleura dioica, a gelatinous zooplankton, was another important zooplankton, showing high density in all samples except in July 1999.

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Analysis of Growth Characteristics and Aboveground Carbon Storage for Zelkova serrata Artificial Forests in Gwangneung Experimental Forest (광릉시험림 내 느티나무(Zelkova serrata) 인공림의 생장특성 및 지상부 탄소저장량 분석)

  • Kim, Hyun-Seop;Bae, Sang-Won;Lee, Sang-Tae;Hwang, Jae-Hong
    • Journal of Korean Society of Forest Science
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    • v.99 no.1
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    • pp.144-152
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    • 2010
  • This study was conducted to analyze the growth characteristics and aboveground carbon storage for old growth Zelkova serrata artificial forests (site1: age class IX, site2: age class VIII) in Gwangneung Experimental Forest. The trees were classified by crown classes for analyzing forest stand structure. The growth characteristics were analized through ringwidth increment by crown classes and stem analysis of dominant trees. There were a wide range of DBH (site1: 8~62 cm, site2: 14~40 cm) and height (site1: 8~26 m, site2: 12~26 m) distributions and revealed different growth characteristics by crown classes in both sites. The mean annual increment (MAI) of ringwidth for the last 5 years of dominant trees for site1 (3.3 mm) was higher than MAI of ringwidth of total growth period (2.3 mm) and MAI of ringwidth for the last 5 years of dominant trees for site2 (2.2 mm) was equal to MAI of ringwidth of total growth period (2.2 mm). Also, the growth increment of ringwidth by crown classes had significant differences between dominant tree and the others crown classes (p<0.01) in both sites. As a results of stem analysis of dominant trees in both sites, there were similar to their volume between site1 (1.106 $m^3$) and site2 (1.035 $m^3$). In spite of old age, the annual increment of volume has been increasing steadily until recent year. Meanwhile, total aboveground carbon storage of site1 (65.6 Mg C $ha^{-1}$) was higher than that of site2 (56.1 Mg C $ha^{-1}$). The proportion of dominant and co-dominant trees to total aboveground carbon storage was more than 90% and the greatest individual aboveground carbon storage by crown classes was dominant tree in all both sites. However, individual aboveground carbon storage of dominant tree in site1 had 0.054 Mg C $tree^{-1}$ more than site2 owing to the differences from average DBH of dominant trees by sites. We think that these results will contribute to the forest practice for Zelkova serrata artificial forests as a basic information.

Native Plants Combination for Ecological Environmental Restoration of the Dissected Sloping Area (절개지 사면의 생태환경 복원을 위한 자생식물 조합)

  • Lee, Chang Shook;Suh, Hyoung Min;Kim, Dong Geun;Eum, Sang Mi;Choi, Sun A;Lee, Nam Sook
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.6
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    • pp.36-50
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    • 2009
  • To suggest the native plants combination for restoration of the dissected sloping area, the plant communities of thirty seven quadrats from five localities of mid-southern part of Korean peninsula were surveyed from 2007 to 2008. Their flora, vegetation structure, and dominant species based on the importance value were investigated. And the soil characters (pH, moisture content, water holding capacity, and organic matter) of each dominant species were analyzed. Also, germination tests were performed to check the stability of restored native plants using seed chips. As a result, 79 native plants were suggested for the dissected sloping area : 20 trees and subtrees for the upper layer, 18 shrubs and vines for the middle layer, and 41 herbs for the lower layer, taken together their flora, dominant species, vegetation structure, soil condition, germination test, flowering period.

The Seismic Behavior of the Truss-Arch Structure by Lead Rubber Bearing and Friction Pendulum System with Seismic Isolation (납고무받침 면진장치와 마찰진자 면진장치에 의한 트러스-아치 구조물의 지진거동 비교)

  • Kim, Gee-Cheol;Seok, Keun-Yung;Kang, Joo-Won
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.374-379
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    • 2008
  • The purpose of seismic isolation system among them is to lengthen the period of structure and make its period shift from the dominant period of earthquake. In this study, the seismic behavior of arch structure with lead rubber bearing(LRB) and friction pendulum system(FPS) is analyzed. The arch structure is the simplest structure and has the basic dynamic characteristics among large spatial structures. Also, Large spatial structures have large vertical response by horizontal seismic vibration, unlike seismic behavior of normal rahmen structures. When horizontal seismic load is applied to the large spatial structure with isolation systems, the horizontal acceleration response of the large spatial structure is reduced and the vertical seismic response is remarkably reduced.

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Network Analysis of East Asian Research in South Korea for the 2004-2013 Period

  • Park, Ji-Young;Park, Han Woo
    • International Journal of Contents
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    • v.11 no.1
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    • pp.52-61
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    • 2015
  • In the past decade, East Asian Research has received attention from researchers as well as in South Korea society-at-large. The broad category of East Asian Research includes various disciplinary fields, such as "history, economics, and politics; however, few studies have used quantitative analysis to explore its development. In this paper, we used network analysis to identify the disciplines and active research areas, focusing on productivity, collaboration patterns, and citation networks of East Asian Research in South Korea. For this study, 6,646 journal publications related with East Asian Research and indexed by KCI (Korean Citation Index) during the 10-year period of 2004-2013 were considered. Results show that East Asian Research was led during this period by sole-researchers, rather than interdisciplinary studies. Moreover, a co-institution network represents active institutions with a high degree and collaborative centrality. In terms of journal-journal citation networks, journals belonging to both "history" and "Korean literature" disciplines were dominant.