• Title/Summary/Keyword: Cluster distribution

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Seasonal Changes in Phytoplankton Composition in Jinhae Bay, 2011 (2011년 진해만 식물플랑크톤 군집의 계절적 변화)

  • Park, Kyung-Woo;Suh, Young-Sang;Lim, Weol-Ae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.6
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    • pp.520-529
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    • 2012
  • Geographic distribution and species composition of phytoplankton were investigated in Jinhae Bay for 12 months. Total 158 species were found including 95 bacillariophyceae, 58 dinophyceae, 1 euglenoids, and 4 dictyochaceae. The total cell numbers of phytoplakton ranged from $4.0{\times}10^3{\sim}9.0{\times}10^7\;cells{\cdot}L^{-1}$. Highest and lowest amounts of cells were found in July (Chl.a 13.19 $mg{\cdot}m^{-3}$) and March(Chl.a 3.44 $mg{\cdot}m^{-3}$), respectively. Leptocylindrus danicus and Pseudo-nitzschia spp. were dominant in spring, and Dactliosolen fragilissimus and Pseudo-nitzschia spp. were dominant in summer. Chaetoceros spp. and Skeletonema spp. were domonant in autumn and winter. The amounts of nitrogen and phosphorus were also measured during the survey. Higher ratio of nitrogen (DIN : DIP = 28 : 1) was found in the east Jinhae Bay compared to the ratio of the west Jnhae Bay that showed 14 : 1 of N : P ratio. The total amounts of nitrogen, phosphorus and Chl.a were also higher in the east Jinhae Bay compared to the west area. The geographic differences between the east and west of Jinhae Bay were also discussed along with phytoplankton compostion.

Species Diversity Analysis of Mushrooms Collected in Mt. Chiak

  • Lee, Byung-Kook;Kim, Kyoung Su;Eom, Ki-Cheol;Seok, Soon-Ja
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.19-19
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    • 2014
  • This study included the analysis of mushroom data collected from Mt. Chiak in Gangwon-do using various methods. Former studies of Korean mushrooms are limited by regional characters and there is less species diversity among the regions. This study tried to find a way for the forecast of mushroom distribution and appearance by indexes of species diversity. The indexes used in this study include the number of fungi (N), the number of species (S), similarity index (C), richness index (R1, R2), variety index (V1, V2), evenness index (E1, E2, E3, E4, E5), and dominance index (D1) to analyze variety of species diversity. Analyses of data of fungi using a multistage cluster sampling indicate that the average value of C for years was higher than the average value of C for areas. The mushrooms consisted of 208 species in 686 individuals in limited fungal collection from 2002 to 2003. One hundred thirty nine species in 393 individuals were collected in 2002, and 122 species 293 individuals were collected in 2003. The individuals collected in 2003 were smaller than 2002's individuals. Similarity, richness, and variety indexes' values of 2003 were reduced than 2002's values but dominance index of 2003 was increased than 2002's value. Generally the species diversity of the environment to evaluate the index of similarity, richness, and variety was a higher index; dominance index was lower than that of the surrounding environment, suggesting a good diversity. As a result, the occurrence of mushrooms in the surrounding environment and the various factors seem fell in 2002 compared to 2003. The majority genus of the limited fungal collection was Mycena genus in 63 individuals; the majority species was Laccaria laccata in 34 individuals. Ninety three species in 106 individuals were collected by the extended collection and the majority genus of the extended collection was Amanita genus in 17 individuals; the majority species was Amanita citrina (Schaeff.) Pers. which was found in 5 individuals. This demonstrates that periodical similarity's value was 0.159 is higher than special similarity's 0.119. This indicates that the probability of the appearance of same mushrooms in the same area in following year is higher than the probability of the appearance of same mushrooms in the surrounding area in same year. The value of coefficient of variation (CV), in which the amount of change is much or less by N is higher than the CV value by S. CV value of dominance index(D) was the highest r point among other indexes, and evenness index (E) was the lowest point among other indexes. The correlation matrix with 66 combinations between the indexes, the combinations with correlations was 46 combinations. These results revealed that indexes of R1, V2, and E1 were proper to represent species diversity of fungi based on the correlation matrix and the theory of statistical independence which means there is no or less mutual association. This research would contribute to the study about variable living creature by measuring method and in the future this would be used to figure out regulation about fungi with their correlation, values in ecosystem, develop improving new models about agricultural fungi species and numbers by investigating agricultural variable species.

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Thermodynamic Study of Poly(dimethylsiloxane)-Solvents Systems Using Inverse Gas Chromatography (Inverse Gas Chromatography를 이용한 Poly(dimethylsiloxane)-Solvent계의 열역학적 연구)

  • Cho, Joung-Mo;Kang, Choon-Hyoung
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.718-725
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    • 1999
  • In order to investigate the interaction characteristics of poly(dimethylsiloxane) (PDMS) with various solvents such as water, ethanol, and iso-propanol, Inverse Gas Chromatography(IGC) at finite concentration, which is a very fast, accurate, and thus promising technique in thermodynamic study of polymer systems, is employed. By measuring the specific retention volumes of the probes, the interaction parameters are calculated by means of the Flory-Huggins equation. From the results, the interaction parameters of the probes are, as expected due to the hydrophobicity of the polymer, found to be of large positive values (2$2.0{\times}10^{-3}mol/g$. For the linear PDMS, interpretation of the space distribution of molecules is performed by the Kirkwood-Buff-Zimm(KBZ) integrals, which give intuitive information about physical properties. From the KBZ integrals, water does not show the tendency of preferential solvation with the PDMS but formed self-cluster. The larger solvent molecules show a stronger tendency to distribute more randomly in the mixture.

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Physico-Chemical Characteristics of Water and Distribution of Vascular Hydrophytes in the West Nakdong River, South Korea (서낙동강 수질의 이화학적 특성과 수생관속식물의 분포)

  • 윤해순;김구연;김승환;이원화;이기철
    • The Korean Journal of Ecology
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    • v.25 no.5
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    • pp.305-313
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    • 2002
  • The physico-chemical characteristics of water and sediment, and structures of vegetation of the vascular hydrophytes were investigated in the West Nakdong River. Water quality was eutrophic according to the mean values and the ranges of water properties such as pH, DO, BOD, chlorophyll a, total nitrogen and phosphate, and other nutrients. A few cases were hypereutrophic for chlorophyll a level in summer. Soil reaction was weak acid. Composition of sediment was mainly sand except in SI(Sinan chideung) of which was mainly clay, and SU(Suan chideung) of which was mainly silt. Flora of vascular hydrophyte had 26 species and 1 variety comprising 16 families. Trapa japonica was dominant species in the sites of DU(Dunchido), GA(Garak chideung) and SU. Nymphoides peltata and Hydrocharis dubia dominated in DA and SI, respectively. Species diversity and evenness were relatively high in SI and SU but dominance was high in DA. After June, water lettuce(Pistia stratiotes) and water hyacinth(Eichhornia crassipes) were flowed from tributary to the river. Standing crop of macrohydrophytes was high in DA from April to August, but it showed maximum standing crop (445g·dw/㎡) in DU after disturbance by explosive growth of exotic plants in October. In comparison with those in 1985, total productivities in DU and GA decreased to 33.5%, and the reduction ratio of dominant species, Trapa japonica was 56.7%. Najas marina, N. minor, Myriophyllum spicatum and Nymphoides indica have disappeared ever since the Nakdong barrage was constructed in the Nakdong river. They were divided into three groups (GA-SU-DU, DA, SI) by cluster analysis. Introduction of the exotic species in this river caused decreasing of endemic plants including endangered species Euryale ferox and rare species Hydocharis dubia, and food plants for waterfowl such as Trapa japonica, Vallisneria asiatica and Potamogeton crispus.

Macrobenthic Community on Angol Tidal Flat in Jinhae (진해 안골조간대에 서식하는 대형저서동물의 군집구조)

  • Paik Sang-Gyu;Yun Byoung Sun;Kim Kgu Hwan;Yun Sung Gyu
    • Korean Journal of Environmental Biology
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    • v.23 no.2 s.58
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    • pp.106-113
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    • 2005
  • This study was conducted to examine the community structure of macrobenthos on Angel tidal flat in Jinhae, south coast of Korea. Monthly samples were conducted at eight sites from March 1998 to February 1999. A total of 110 species were sampled with a mean density of 322ind. $m^{-2}$ and biomass of 98.4 wwt g $m^{-2}$. Of these species, there were 44 species of polychaetes $(40.0\%)$, 41 species of crustaceans $(37.3\%)$ and 16 species of molluscs $(14.5\%)$. The major density dominant species were a gastropod Batilaria cumingi (52ind. $m^{-2}$) and five polychaetes Ceratonereis erythraeensis (38ind. $m^{-2}$), Cirriformia tentaculata (32ind. $m^{-2}$), Capitella capitata (23ind. $m^{-2}$), Sigambra tentaculata (23ind. $m^{-2}$), Glycera chirori (17ind. $m^{-2}$). Cluster and MDS analysis showed that the study sites could be divided into two tidal elevation groups. According to the spatial distribution of dominant species and SIMPER analysis, the two groups were characterized by Sigambra tentaculata - Chaetozone setosa in upper species group and Ceratonereis erythraeensis-Cirriformia tentaculata-Capitella capitata in lower species group.

Current States of the Global Water Market and Considerations for the Groundwater Industry in South Korea (물 시장의 현주소와 지하수 산업에 대한 고찰)

  • Kim, Byung-Woo;Koh, Yong-Kwon;Choi, Doo-Houng;Kim, Deog-Geun;Kim, Gyoo-Bum
    • The Journal of Engineering Geology
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    • v.24 no.3
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    • pp.431-440
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    • 2014
  • Since the establishment of the Groundwater Act in Korea in 1993, the national policy on groundwater has focused on the preservation and management of groundwater, which should be used only as a subsidiary water resource. However, population growth, increased water demand, climate change, and the need for uniform water distribution have brought changes to groundwater policy, and have led to the prioritization of development projects such as groundwater dams and river bank filtration. Population growth, changes to the water environment, and increased water risks have all played a role in triggering rapid growth within the water industry; the size of the investment in water resources will also continue to increase worldwide. Until now, private wells and bottled mineral water have led the groundwater industry in South Korea. However, a new area of the groundwater industry, which includes the health and medical sciences, employs groundwater properties derived from regional geology, and is growing. This requires the advancement of groundwater research and technical development connected with ICT (Information and Communication Technology) and medical science, and that the public development of groundwater and its various applications is expanded through locating groundwater in the core of the water industry cluster.

The Characterization of Fish Communities in Urban Streams of the Busan Metropolitan City and Suggestions of Stream Restoration (부산시 도시하천의 어류군집과 하천복원을 위한 제안)

  • Yoon, Ju-Duk;Jang, Min-Ho;Oh, Dong-Ha;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.40 no.2
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    • pp.303-317
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    • 2007
  • The fish community of small freshwater ecosystems gets easily disturbed by direct or indirect human induced disturbances during the period of urbanization. Urbanization is one of factors that generate changes in stream and influences fish fauna in developed countries. This study was conducted in Busan Metropolitan City from 2001 to 2004. In order to investigate the fish community, the city was divided into 3 parts, eastern, central and western. A total of 3,206 individuals of 46 species from 19 families were collected from 55 sites. The dominant species was Rhynchocypris oxycephalus, whereas Zacco temminckii was the subdominant species. Cluster analysis was conducted using primary freshwater fish species collected from each stream. As a result of the analysis, study sites were well differentiated into 3 parts. Two species of Z. temminckii and R. oxycephalus represented the upper part of the stream and Carassius cuvieri, Acheilognathus rhombeus, Hemiculter eigenmanni and Micropterus salmoides represented the middle and lower parts of the stream. When compared with previous studies, fish community of the eastern part of the Busan city where urbanization is in progress, showed similar patterns to the central part. At the time of the habitat restoration of fish fauna in stream, appropriate selection of fish species should be made through analysis of stream character and biogeographic distribution of fish, and long-term monitoring is also needed for sustaining the management of fish fauna.

Prevalence Rate of Cognitive Impairment and Dementia Among the Elderly in Busan (부산지역 거주 노인의 인지기능장애 및 치매 유병률)

  • Kim, Jung-Soon;Lee, Su-Ill;Chung, Young-In;Hwang, In-Kyung;Yih, Bong-Sook;Kim, Min-Jeong;Cho, Eu-Soo;Chun, Jin-Ho;Jeong, Ihn-Sook
    • Journal of Preventive Medicine and Public Health
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    • v.36 no.1
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    • pp.63-70
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    • 2003
  • Objectives : To investigate the prevalence of cognitive impairment and dementia in elderly people, aged 65 or above, residing in Busan Metropolitan City. Methods : Total of 1,101 old people, aged 65 or above, living in Busan as of December 31, 2001 were selected using stratified three-stage cluster sampling. Cognitive impairment was determined from the MMSE-K score, and dementia confirmed from five psychometric measures and the Barthel index. The crude prevalence, sex-age adjusted for the Korean population, were obtained. Results : With the cut-off point for cognitive impairment was set at 24 points, or below, on the MMSE-K scale, the crude rate of cognitive impairment was 29.3% (15.7% for men and 37.5% for women), and the sex-age adjusted prevalence was 30.5% (17.5% for men and 37.0% for women). When the cut-off point for cognitive impairment was set at 20 points, or below, on the MMSE-K scale, the crude rate of cognitive impairments were 10.0% (4.1% for men and 13.5% for women), and 10.6% (4.7% for men and 13.1% for women), respectively. The crude dementia, and the sex-age adjusted rates were 7.4% (2.4% for men and 10.5% for women), and 8.0% (2.7% for men and 10.0% for women), respectively. Conclusions : The prevalence of dementia in this study was somewhat lower than that reported by other domestic and foreign studies. Our results related to the difference in time and space, diagnostic tools, response rates, and distribution of male and female subjects, etc.

Synthesis and characterization of sulfonated poly(arylene biphenylsulfone ether) copolymers containing hydroquinone moiety for polymer electrolyte membrane (고분자 전해질 멤브레인용 하이드로퀴논 부분이 포함된 설폰화된 폴리(아릴렌 비페닐설폰 에테르) 공중합체의 합성과 특성평가)

  • Yoo, Dong-Jin
    • Journal of Energy Engineering
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    • v.19 no.2
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    • pp.121-127
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    • 2010
  • In present work, sulfonated poly(arylene biphenyklsulfone ether) copolymers containing hydroquinone moiety were successfully synthesized using 4,4'-bis[(4-chlorophenyl)sulfonyl]-1,1'-biphenyl(BCPSBP), hydroquinone sulfonic acid potassium salt(sHQ), 4,4'-sulfonyldiphenol and evaluated their characteristics. Three kinds of polymer electrolyte membranes, PBPSEH-HQ00, PBPSEH-HQ10 and PBPSEH-HQ30 were prepared by using mole fraction of sulfonated hydroquinone(sHQ). The structure of the fabricated polymers was analyzed using NMR, IR and GPC. The Mw(weight-average molecular weights) of the polymers were in the range of 62,000-213,000 g $mol^{-1}$, and the molecular weight distribution (Mw/Mn) varied from 1.66-4.04. The thermal analysis of the copolymers was carried out by TGA and DSC. The temperature of Td5% and Td10% was decreased with the mole fraction of sHQ but Tg was increased with the mole fraction. The water uptake, IEC and ion conductivity were increased with increasing the ionic cluster of the polymers. The proton conductivity equal to 9.4 mS $cm^{-1}$ was measured for the PBPSEH-HQ30 membrane at $90^{\circ}C$ and 100% relative humidity. From the observed results it is clear that the prepared hydrocarbon membrane can be considered as suitable polymer electrolyte membrane for the application of PEMFC.

Study on Spatial Characteristics of Student Transfer in Southern Area of Gyeonggi Province (경기도 남부지역 학생이동의 공간적 특성에 관한 연구)

  • Kim, Hyung-Mi;Joo, Kyung-Sik
    • Journal of the Korean association of regional geographers
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    • v.17 no.6
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    • pp.679-697
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    • 2011
  • This study analyzed the characteristics of spaces to and from which middle school students transfer, especially centering around the school districts of Southern area in Gyeonggi Province such as Suwon, Osan, Yongin, and Hwaseong. This study was conducted to provide the suggestions regarding educational policies such as the positioning to appropriate school districts, improving of educational environment, and implementing of educational equity, by analyzing, based on the empirical data, the educational spaces of four cities showing rapid population growth due to recent suburbanization. The characteristics of distribution of variables such as schools for each district affecting the student transfer, housing development, and socioeconomics in the research object region are mainly analyzed through the correlation analysis, multiple regression analysis, and cluster analysis. As a result, there is shown a distinct spatial difference between school districts of the cty downtown and urban fringe, and between school districts of the conventional cities(cities that have been from the past: note of translator) and new land development regions. First, the school districts in the city downtown showed lots of transfers between neighboring school districts, while the school districts in the urban fringes showed transfer-out tendencies strongly. Second, it was the new land development regions where the transfer-in rate is the highest in the Southern area of Gyeonggi Province. Third, the said new land development regions required the supply of educational installations and educational support that can meet educational demands, since these regions have relatively lower qualitied educational environments compared to the conventional cities where the fluidity of students is lower. Fourth, in the summary of all of the said three results, the student transfer in the southern area of Gyeonggi Province was shown in the spaces centering around the multi-core area by reflecting the restructuring of suburban area.

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