• Title/Summary/Keyword: assemblage

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Hydrothermal Alteration of Miryang Pyrophyllite Deposit (밀양납석광상의 열수변질 특징)

  • Moon, Dong Hyeok;Kwak, Kyeong Yoon;Lee, Bu Yeong;Koo, Hyo Jin;Cho, Hyen Goo
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.3
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    • pp.265-277
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    • 2015
  • Hydrothermal alteration patterns and environment are studied by mineral assemblages and chemical analyses of surface and core samples from Miryang pyrophyllite deposit. The alteration zones of this deposit can be divided into three zones on the basis of mineral assemblage; advanced argillic, phyllic, and propylitic zone. Advanced argillic zone mainly consists of pyrophyllite-dickite (-quartz) and corresponds to principal mining ore. The common mineral assemblage of phyllic zone and propylitic zone are sericite-quartz-dickite and chlorite-quartz, respectively. Horizontal and vertical alteration patterns and major element geochemistry indicate that pyrophyllite ores have been formed several times by hydrothermal alteration. And it also suggests that the huge ore bodies may be extended from the deeper part of recent quarries to the south-southeastern direction. The paragenesis of ore minerals and polytype (2M) suggest that ore deposit was formed at about $300-350^{\circ}C$.

Seasonal variations in species composition of fish assemblage collected by trammel net in coastal waters of the East Sea (동해 연안 자망에서 채집된 어류 종조성의 계절변동)

  • Choi, Kwang Ho;Han, Moon Hee;Kang, Chang-Keun;Park, Joo Myun;Choi, Jung Hwa;Park, Jeong-Ho;Sohn, Myong Ho;Baeck, Gun Wook;Choy, Eun Jung;Lee, Chung Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.415-427
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    • 2012
  • Seasonal variation in species composition and abundance of fish assemblage in the north coast (NC: Ayajin) and central coast (CC: Hupo) of the East Sea were calculated using samples collected by trammel net during 2011-2012. A total of 20 species from NC and 17 species from CC were collected. Of the fishes collected, the dominant fish species were Glyptocephalus stelleri and Careproctus rastrinus in the NC, and Dasycottus setiger and G. stelleri in the CC. These 2 fishes accounted for 71.7% and 81.0% of the total number of individuals collected in the NC and CC, respectively. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The cluster analysis and non-metric multidimensional scaling (MDS) based on Bray-Curtis similarity revealed that the fish assemblages classified into north and central groups. Analysis of similarity percentages of species contributions (SIMPER) indicated that most individual of G. stelleri and Gadus macrocephalus contributed to north group, and D. setiger and G. stelleri in central group, whereas 15 species contributed to 90% of the dissimilarity.

Species Composition and Seasonal Variation of Fish Assemblage in the Coastal Water off Gadeok-do, Korea -3. Fishes Collected by Crab Pots- (가덕도 주변 해역 어류의 종조성과 계절 변동 -3. 꽃게통발에 의해 채집된 어류-)

  • An Yong Rock;Huh Sung Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.6
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    • pp.715-722
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    • 2002
  • The monthly collected fish samples by crab pots were analyzed in order to study the species composition and seasonal variation of fish assemblage in the coastal water off Gadeok-do, Korea in 1998, During the study period, 49 species of fishes representing 26 families were collected, The dominant species were Conger myriaster, Sebastes inermis, Hexagrammos otakii, H. agrammus, Stephanolepis cirrhifer and Acanthogobius flavimanus. These 6 dominant species accounted for $67.1\%$ and $69.4\%$ in the number of individuals and biomass, respectively. The secondary importance species were Thamnaconus modestus, Takifugu niphobles, Rudarius ercodes, Dictyosoma burgeri, Sebastes longispinis and Epinephelus septemfasciatus. The highest number of species was collected in November, and the number of individuals and biomass were highest in March. But the lowest numbers of species and individuals were collected in July and the lowest biomass in September, Although the species diversity indices varied little monthly, the lowest value was recorded in August because of small number of species and predominance of 5. cirrhifer and T. modestus.

Faunal Assemblages of Benthic Macrofauna in the Inter- and Subtidal Region of the Inner Kyeonggi Bay, West Coast of Korea (서해 경기 내만해역 조간대, 조하대의 저서동물군집)

  • Shin, Hyun Chool;Choi, Jin Woo;Koh, Chul Hwan
    • 한국해양학회지
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    • v.24 no.4
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    • pp.184-193
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    • 1989
  • An investigation on the soft-bottom macrobenthic community in the inner Kyeonggi Bay was conducted in July, October of 1987 and February, May of 1988. The benthic fauna comprised a total of 87 species and showed mean density of 550 indiv./$m^2$. Major faunal groups are polychaetes, molluks, and crustaceans, corresponding to 64.7%, 17.4%, and 15.2% in total abundance respectively. The most abundant species was Tharyx sp. (10.9%), and followed by Mactra veneriformis (10.5%), Mediomastus sp. (8.6%), and Glycinde sp. (8.0%) etc.. The important species in the intertidal zone were Mactra veneriformis, Hinia festiva, and Nephtys californiensis, whereas those in subtidal channel region were Tharyx sp., mediomastus sp., Sternaspis scutata, and Nephtys polybranchia. The study area could be divided into 4 station groups based on the species composition; two groups within interidal flat and two in channel regions. Each station group sustained its specific benthic faunal assemblage; Mactra-Hinia, Aricidea-Haploscoloplos assemblages in the intertidal flat and Harpiniopsis-Urothoe, Mediomastus-Sternaspis assemblages in the subtidal channel region. The Mediomastus-Sternaspis assemblage showed the highest species number and population density, and also did the highest diversity and evenness indices. The Harpiniopsis-Urothoe assemblage showed the poor species composition and abundance, and so recorded the highest dominance index. Two assemblages in the intertidal flat had the intermediate values in all the biological parameters. The northern channel region of zone S-2 showed the high abundance in species composition, which seems to be caused by the heterogeneous sediment and the organic enrichment from the Han River and the Incheon industrial complex.

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The Bronze Ceremonial Vessels of Xiaoheishigou Stone Cist Tomb 8501 seen through Comparison with the Chinese Zhongyuan Region (중국 중원 지역과의 비교를 통하여 본 소흑석구 8501호 석곽묘의 청동예기)

  • Oh, Kang-won
    • Korean Journal of Heritage: History & Science
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    • v.47 no.3
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    • pp.86-107
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    • 2014
  • The large stone cist tomb 8501 of Lingcheng prefecture Xiaoheishigou, according to Chinese chronology, was built during the late Western Zhou period. However in this tomb not only Chinese Zhongyuan style bronze ceremonial vessels but also indigenous style bronze ceremonial vessels and instruments and hybrid bronze ceremonial vessels with a mixture of both indigenous and Chinese styles were excavated in large numbers. The bronze ceremonial vessel assemblage of Xiaoheishigou, in comparison with the decorum regulations and bronze cauldron and coffer system of the Chinese Zhongyuan region of the same time period, belong to that of the lowest status category. However, in contrast to the lowest class category tombs of the Chinese Zhongyuan region, in this tomb, with the exception of cauldrons and coffers, the remaining food and wine vessels of the assemblage match the standard of emperors and feudal rulers of vassal states. This is reinforced by the burial of musical instruments. Of the bronze ceremonial vessels of Xiaoheishigou large stone cist tomb 8501, the indigenous and hybrid styles, in consideration of manufacture technology seem to have been manufactured locally. However, the form, pattern and also the standards of the Western Zhou style bronze ceremonial vessels are identical to those of the Chinese Zhongyuan region and therefore it is clear that they were manufactured in Western Zhou. The reason for these precious ceremonial vessels which were manufactured and used in the many individual vassal states of the Chinese Zhongyuan region being buried in Xiaoheishigou, seems to have been the result of economic exchange and friendly political relations between the Xiaoheishigou and other groups rather than these vessels having been plundered by the Xiaoheishigou group. A distinct cultural sphere existed between the Upper Xiajiadian culture and Western Zhou which interacted frequently with both sides.

Simulating Pedestrian Evacuation Using Geographic Information Technologies

  • Jingjing, Shi;Hui, Lin
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.414-416
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    • 2003
  • Pedestrian assemblage is now a normal phenomenon in modern cities. To maintain an unblocked traffic situation, protect the pedestrians' safety and make preparedness for any emergencies is an important task for police department. Modeling pedestrian dynamics and simulating evacuation process can provide useful information for make accurate decisions. In this paper, by virtue of geographic information technologies, the authors proposed a conceptual framework to simulate pedestrian dynamics and evacuation in an open urban environment.

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Fish Assemblage in the Tidal Creek of Sangnae-ri Suncheon, Korea (순천 상내리 갯골에 출현하는 어류군집)

  • Ye, Sang Jin;Jeong, Jae Mook;Kim, Hyun Ji;Park, Joo Myun;Huh, Sung Hoi;Baeck, Gun Wook
    • Korean Journal of Ichthyology
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    • v.26 no.1
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    • pp.74-80
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    • 2014
  • Seasonal variation in species composition and abundance of fish assemblage in the tidal creek of Sangnae-ri Suncheon, Korea were studied using monthly samples collected by a push net from April 2011 to March 2012. During the study period, a total of 1,095 individuals belonging to 13 species in 6 families were collected. The dominant fish species were Tridentiger bifasciatus, Mugil cephalus and Favonigobius gymnauchen. These three fish species accounted for 86.6% of the total number of individuals collected. The number of fish species, number of individuals, biomass fluctuated with season showing a low value in winter and high value in spring.

Diatom Succession Representing the Paleoclimatic Change from Laminated Sediments around Antarctica (남극 엽층리 퇴적물로부터 규조 종을 이용한 고기후 변화 연구)

  • Bak, Young-Suk;Yoon, Ho Il;Yoo, Kyu-Cheul;Lee, Young-Up
    • Journal of the Korean earth science society
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    • v.36 no.2
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    • pp.190-197
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    • 2015
  • This study investigated the paleoclimatic change using diatoms that were extracted from the high-resolution laminated layers of diatom ooze sediment cores GC08-EB01 in the eastern basin of the Bransfield Strait, Antarctica. The range of diatom valves per gram of dry sediment was from $0.4-4.2{\times}10^8g^{-1}$ in quantitative diatom assemblage analysis. Laminations are classified using visually dominant diatom species and terrigenous content. Biogenic diatom ooze laminae characterised by bloom of Corethron crilophilum, Eucampia antarctica, Fragilariopsis curta, F. kerguelensis, Odontella weissflogii, Proboscia inermis, R. styliformis, Thalassiosira antarctica, and Chaetoceros resting spores. Terrigenous laminae characterised by mixed diatom assemblage. The ratio of (Fragilariopsis curta+F. cylindrus)/Thalassiosira antarctica increase in horizons, suggesting increased sea-ice cover in the study area during the late Holocene (cold events). As a result, five cold events are identified on the basis of frequency of the critical taxa throughout the section.

Distribution of Fish Larvae and the Front Structure of the Korea Strait in Summer (여름철 대한해협의 전선구조에 따른 자치어의 분포 특성)

  • Kim, Sung;Yoo, Jae-Myung
    • Korean Journal of Ichthyology
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    • v.11 no.1
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    • pp.72-85
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    • 1999
  • A study on the larval fish assemblage around the front area was conducted in the Korea Strait in August, 1993. The front was found in the shelf break located in $35{\sim}36^{\circ}N$. A total of 125 species were found in the study area. Of these Engraulis japonicus was the most dominant species comprising 84.3% of the total fish larvae collected and followed by Maurolicus muelleri accounting for 7.7%. Gobiidae, Callionymidae and Pomacentridae showed higher frequency of occurrence. These five species can be divided into three groups. First group was comprised in the larval fish species such as E. japonicus and Callionymidae which were found in the whole study area. The second group was comprised of Gobiidae and Pomacentridae which were found in the warm area located in the southern part of the front area. The other species was M. muelleri found in the cold area located in the northern part of the front area including the front area. The assemblage, geological distribution and body length composition of the fish larvae in the Korea Strait would be mainly determined by the spawning ecology of the fishes, and the geological distribution and structure of the front which is formed in the ocean boundary between the Tsushima Current and the East Sea Cold Water.

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Community Structure of Larval Fish Assemblage in the Coastal Waters of South-central Korea during Spring and Summer (봄-여름 남해 중부 연안 자어 군집구조)

  • Yoo, Joon-Taek;Kim, Yeong Hye;Lee, Seung Hwan;Kim, Jin-Koo
    • Korean Journal of Ichthyology
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    • v.29 no.1
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    • pp.80-86
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    • 2017
  • We examined monthly variations in community structure of larval fish assemblage in the coastal waters of south-central Korea in spring and summer, 2016. A total of 31 taxa of larvae were collected during the study period. Engraulis japonicus larvae were predominated in spring than summer. The larvae of Cynoglossus abbreviates, a spring spawners, were exclusively collected in spring, while those of Nibea albiflora, a summer spawners, were exclusively caught in summer. Due to those seasonal differences in abundance of the dominant species, larval fish community was divided into two main seasonal groups (i.e. April~May and June~August). In addition, summer group was divided into two significant subgroups (June~July and August). During August, the larvae of E. japonicus and N. albiflora sharply decreased in abundance due to abnormally high sea water temperature that was raised up to $28^{\circ}C$, with the temperature being out of range of their optimum spawning temperature.