• Title/Summary/Keyword: representative region

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Diversity and Ecological Importance of Foliicolous Lichens in Korea

  • Oh, Soon-Ok
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.49-49
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    • 2014
  • South Korea is covered primarily by temperate vegetation; therefore, foliicolous lichens may not be expected to play an important role in its lichen flora. Indeed, more than 100 years after the first lichen record from South Korea reported by Hue, the paper "Pyrenocarpous lichens in Korea" published by Moon and Aptroot, reported on the presence of two foliicolous lichens, Strigula nemathora Mont, and S. smaragdula Fr., for the first time in South Korea. No detailed reports on foliicolous lichens have since been published in South Korea. In Japan, the neighboring country, approximately 83 foliicolous lichen species are distributed at the southernmost part under temperate to subtropical climatic conditions. However, a large number of foliicolous lichens, with many recent records, have been reported in neighboring countries like China and Taiwan. According to Thor et al., studies on foliicolous lichen flora of Asia are comparatively poor compared to those reported from America. There are six lichenogeographical regions: the Neotropics, Valdivia, Tethyan, African Paleotropics, eastern Paleotropics, and Neozelandic-Tasmanian, which are demarcated based on the known worldwide distribution pattern of foliicolous lichen flora. South Korea belongs to the eastern paleotropic region, where a higher number of local endemic foliicolous lichens have been reported. So far, there are a total of six known foliicolous lichen taxa from South Korea; S. concreta, S. macrocarpa, S. melanobapha, S. nemathora, S. smaragdula, and S. subelegans from Jeju Island. So far, the genus Strigula is the only known representative of the foliicolous lichen flora in South Korea. Among the recorded species, S. concreta, S. smaragdula, and S. subelegans are abundant and widespread. Japan, the closest area to Jeju Island, has the same distribution pattern of foliicolous lichens, with S. smaragdula, S. melanobapha, and S. subtilissima. Pollen studies conducted by Chung reported that changes in vegetation on Jeju Island, due mainly to deglacial warming and the influence of geographical change, resulted from sea-level rises. In general, all of the foliicolous lichens observed so far were restricted to the southernmost part of South Korea, particularly Jeju Island. Island might be influenced by its geographical setting. One reason could be the close dispersal distances of spores and vegetative propagules from areas such as the southern part of Japan and eastern part of China, where more foliicolous lichens can be found. Thor et al. also showed that the southern part of Japan harbors more foliicolous lichens than the northern part. Considering that China is close to Jeju Island, many foliicolous lichens, including S. concreta, S. macrocarpa, S. nemanthora, and S. smaragdula, have been reported from Yunnan province, the southernmost part of China. Geographically, this province is far away from Jeju Island. In other provinces, such as Shandong, Jiangsu, Shanghai, and Zhejiang, which are closer to Jeju Island, no foliicolous lichens have been recorded so far. Therefore, the chance of spores and propagules coming from such closer areas is questionable. Thus, the location of origin of ancestors of foliicolous lichens of South Korea and the time and means of their invasion of this island is controverisial. The current study would lead the way to finding answers to the above mentioned questions.

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Characteristics of Vegetation Structure in the Ridgeline Area of the Nakdong-Jeongmaek (낙동정맥 마루금 일대의 식생구조 특성)

  • Park, Seok-Gon;Kang, Hyun-Mi
    • Korean Journal of Environment and Ecology
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    • v.30 no.3
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    • pp.386-398
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    • 2016
  • To understand the vegetation structure in the ridgeline area of Nakdong-jeongmaek, six primary areas in Nakdong-jeongmaek were selected and their vegetation distribution was surveyed considering the environmental conditions and artificial influences. According to the results of community classification based on TWINSPAN, the vegetation in the surveyed region was categorized into 9 groups: Betula costata-Quercus mongolica community, Q. mongolica community, Pinus densiflora-Q. mongolica community, P. densiflora community, Deciduous oaks-P. densiflora community, Deciduous oaks community, P. thunbergii community, P. koraiensis-P. rigida community, and Chamaecyparis obtusa-Alnus firma community. In Baekbyeongsan(Mt.) located in Taebaek-si of Gangwon-do, Betula costata-Quercus mongolica community was found, reflecting the environmental characteristics of northern temperate climate. P. thunbergii community appeared in Gudeoksan(Mt.) of Busan metropolitan city, which is near the coast. Since Gudeoksan(Mt.) is near to the downtown and its altitude above the sea is relatively low, people visit the area often. Therefore, C. obtusa and P. thunbergii have been planted for producing forest trees and implementing anti-erosion afforestation. In the other primary survey areas, Q. mongolica-dominant communities, P. densiflora-dominant communities, and deciduous oak-dominant communities, which are representative forest vegetation types of Jeongmaeks in South Korea, were mainly distributed, showing no significant difference compared to the forest vegetation types of other Jeongmaeks. Since the Nakdong-jeongmaek from south to north, it shows clear characteristics of vegetation changes between the northern temperate climate and the warm temperate climate of the south.

Selective Isolation and Phylogeny of the Yeast Species Associated with Aloe vera and Aloe saponaria (알로에 베라(A. vera)와 알로에 사포나리아(A. saponaria)로 부터 효모의 분리 및 계통분석)

  • Choi, Sungchang;Kim, Myung-Uk;Kim, Jong-Shik
    • Korean Journal of Environmental Agriculture
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    • v.32 no.3
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    • pp.240-243
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    • 2013
  • BACKGROUND: Several yeast species have potential applications in biotechnology and the identification of such yeast species is of great interest. The first step in the identification of yeasts is the establishment of an effective isolation method. Thus, we compared the efficacy of different yeast media in the isolation of yeast associated with Aloe vera and Aloe saponaria. METHODS AND RESULTS: In this study, we spread homogenized A. vera and A. saponaria leaves onto 4 different yeast selective media containing chloramphenicol, streptomycin, Triton X-100 and L-sorbose. We observed high selectivity for yeast and many colonies on media. We isolated 67 yeast strains from A. vera and 42 yeast strains from A. saponaria. We used phylogenetic analysis to identify the yeast isolates based on ITS region sequencing and performed sequence analysis on representative isolates from each agar plate. Further, we compared the sequences obtained with reference sequences. The yeast species isolated from A. vera were as follows: 56 isolates of Meyerozyma, 9 isolates of Cryptococcus, and 1 isolate each of Rhodotorula and Sporobolomyces. Those isolated from A. saponaria were as follows: 41 isolates of Rhodosporidium and 1 isolate of Sporobolomyces. CONCLUSION(S): All the isolates obtained using large agar plate containing chloramphenicol, streptomycin, Triton X-100 and L-sorbose were identified as yeast. Therefore, we concluded that this method is useful for selective screening of yeast species.

Distribution Pattern of dominant Benthic Diatoms on the Mangyung-Dongjin Tidal Flat, West Coast of Korea (서해 만경-동진 조간대의 주요 우점 저서 규조류의 분포)

  • 오상희;고철환
    • 한국해양학회지
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    • v.26 no.1
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    • pp.24-37
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    • 1991
  • Marine benthic diatoms and environmental factors were studied at 60 sites on the Mangyung-Dongjin tidal flat of the west coast of Korea. Sediment samples were taken quantitatively from the upper 5 mm layer to obtain a representative estimate of the epipelic and epipsammic cell concentration. Surface sediments taken simultaneously with the quantitative diatom samples were analysed for the grain size. Exposure duration of study sites were calculated by the tide data recorded at Kunsan Outer-Harbour. Coarse sediments dominated mainly on the offshore coastal and lower tidal flat, whereas fine sediments occurred on inner and higher tidal flat. Total 371 diatom taxa were collected and the genera represented by a great number were Navicula and Nizschia. The 16 abundant species occupying more than 1% of total cell number are of the following: Paralia sulcata, Navicula sp. 1, Navicula arenaria, Cymatosira belgica, Amplora holsatica, Amphora coffeaeformis, Achnanthes hauckiana, Rhaphoneis amphiceros, Thalassionema nitzschioides. Navicula sp. 2, Dimeregramma minor, Amphora sp. 1, Cyclotella atomus, C, striata, Nitzschia kuetzingiana, Stephanodiscus sp. 1. The distribution pattern of these dominant species are described in relation to the habitat condition. Most of these species showed high densities in fine sediments. However, they occurred even silty sand and sandy sediments in low abundance. The epipsammic forms belonging to the Araphidineae and Monoraphidineae were restricted on the lower tidal flat. The typical species found in coarse sediments were: Cocconeis sp. 1, Opephora martyi, Amphora sabyii, Dimeregramma minor var. nana, Fragilaria virescens var. oblongella, F. virescens, Cocconeis grata. The higher tidal flat consisting of fine sediments showed relatively higher cell numbers than the lower tidal flat. River mouth region was the highest in abundance.

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Occurrence of Gray Mold Caused by Botrytis cinerea on Common Fig in Korea (Botrytis cinerea에 의한 무화과 잿빛곰팡이병)

  • Cheong, Seong-Soo;Choi, In-Young;Lee, Wang-Hyu
    • The Korean Journal of Mycology
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    • v.41 no.1
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    • pp.38-41
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    • 2013
  • In 2010 and 2011, gray mold was found on common fig (Ficus carica) fruit grown at the research field of Jeollabuk-do Agricultural Research and Extension Services, Korea. Gray mold symptoms on common fig fruit mainly occurred after harvest season until December. The typical symptom included brown water-soaked rot and fruit decay. The diseased fruit was covered by gray to brown colored conidiophore and conidia. The conidiophores were tree shape and measured $15-33{\times}2{\mu}m$. Conidia on conidiophore were ellipsoidal or lemon shape, colorless, single cell, and measured $7.3-14.6{\times}6.8-11.1{\mu}m$. The nucleotide sequences of the rDNA ITS region obtained from the pure culture of the gray mold on common fig were 100% similar to the sequences of the GenBank accession number HQ171052, EU519210, HQ171053, FN812726, HM849615, and EU563120 of B. cinerea isolates. In phylogenetic tree, the representative isolate was placed within same clade of B. cinerea. Based on the morphological characteristics and analysis of rDNA ITS sequence data, the fungus was identified as B. cinerea.

Analyzing Effective Thermal Conductivity of Rocks Using Structural Models (구조모델을 이용한 암석의 유효열전도도 분석)

  • Cha, Jang-Hwan;Koo, Min-Ho;Keehm, Young-Seuk;Lee, Young-Min
    • Economic and Environmental Geology
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    • v.44 no.2
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    • pp.171-180
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    • 2011
  • For 21 rock samples consisting of granite, sandstone and the effective thermal conductivity (TC) was measured with the LFA-447 Nanoflash, and mineralogical compositions were also determined from XRD analysis. The structural models were used to examine the effects of quartz content and the size of minerals on TC of rocks. The experimental results showed that TC of rocks was strongly related to quartz content with $R^2$ value of 0.75. Therefore, the proposed regression model can be a useful tool for an approximate estimation of TC only from quartz content. Some samples with similar values of quartz content, however, illustrated great differences in TC, presumably caused by differences in the size of minerals. An analysis from structural models showed that TC of rocks with fine-grained minerals was likely to fall in the region between Series and EMT model, and it moved up to ME and Parallel model as the size of minerals increased. This progressive change of structural models implies that change of TC depending on the size of minerals is possibly related to the scale of experiments; TC was measured from a disk sample with a thickness of 3 mm. Therefore, in case of measurements with a thin sample, TC can be overestimated as compared to the real value in the field scale. The experimental data illustrated that the scale effect was more pronounced for rocks with bigger size of minerals. Thus, it is worthwhile to remember that using a measured TC as a representative value for the real field can be misleading when applied to many geothermal problems.

The Evaluation Analysis of Competitiveness among Ports in ASEAN & Korea - An Application of HFP Model - (HFP방법을 적용한 ASEAN과 한국항만의 경쟁력 평가분석)

  • 김진구;전일수
    • Proceedings of the Korean Association for Survey Research Conference
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    • 2003.06a
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    • pp.140-160
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    • 2003
  • The purpose of this study is to identify and evaluate the competitiveness of ports in ASEAN(Association of Southeast Asian Nations), which plays a leading role in basing the hub of international logistics strategies as a countermeasure in changes of international logistics environments. This region represents most severe competition among Mega hub ports in the world in terms of container cargo throughput at the onset of the 21st century. The research method in this study accounted for over lapping between attributes, and introduced the HFP method that can perform mathematical operations. The scope of this study was strictly confined to the ports of ASEAN, which cover the top 100 of 350 container ports that were presented in Containerization International Yearbook 2002 wi th reference to container throughput. The results of this study show Singapore in the number one position. Even compared with major ports in Korea (after getting comparative ratings and applying tile same data and evaluation structure), the number one position still goes to Singapore and then Busan(2) and Manila(2), followed by Port Klang(4), Tanjung Priok(5), Tanjung Perak(6), Bangkok(7), Inchon(8), Laem Chabang(9) and Penang(9). In terms of the main contributions of this study, it is the first empirical study to apply the combined at tributes of detailed and representative attributes into the advanced HFP model which was enhanced by the KJ method to evaluate the port competitiveness in ASEAN. Up-to-now, none have comprehensively conducted researches with sophisticated port methodology that has discussed a variety of changes in port development and terminal transfers of major shipping lines. Moreover, through the comparative evaluation among major ports in Korea and ASEAN, the presentation of comparative competitiveness for Korean ports is a great achievement in this study. In order to reinforce this study, it needs further compensative research, including cost factors which could not be applied to modeling the subject ports by lack of consistently qualified data in ASEAN.

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Atmospheric Dispersion of Radioactive Material according to the Local Wind Patterns around the Kori Nuclear Power Plant using WRF/HYSPLIT Model (WRF/HYSPLIT 모델을 이용한 고리원전 인근 국지바람 패턴에 따른 방사성물질 대기확산 특성)

  • An, Hye Yeon;Kang, Yoon-Hee;Song, Sang-Keun;Bang, Jin-Hee;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.24 no.1
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    • pp.81-96
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    • 2015
  • The characteristics of atmospheric dispersion of radioactive material (i.e. $^{137}Cs$) related to local wind patterns around the Kori nuclear power plant (KNPP) were studied using WRF/HYSPLIT model. The cluster analysis using observed winds from 28 weather stations during a year (2012) was performed in order to obtain representative local wind patterns. The cluster analysis identified eight local wind patterns (P1, P2, P3, P4-1, P4-2, P4-3, P4-4, P4-5) over the KNPP region. P1, P2 and P3 accounted for 14.5%, 27.0% and 14.5%, respectively. Both P1 and P2 are related to westerly/northwesterly synoptic flows in winter and P3 includes the Changma or typhoons days. The simulations of P1, P2 and P3 with high wind velocities and constant wind directions show that $^{137}Cs$ emitted from the KNPP during 0900~1400 LST (Local Standard Time) are dispersed to the east sea, southeast sea and southwestern inland, respectively. On the other hands, 5 sub-category of P4 have various local wind distributions under weak synoptic forcing and accounted for less than 10% of all. While the simulated $^{137}Cs$ for P4-2 is dispersed to southwest inland due to northeasterly flows, $^{137}Cs$ dispersed northward for the other patterns. The simulated average 137Cs concentrations of each local wind pattern are $564.1{\sim}1076.3Bqm^{-3}$. The highest average concentration appeared P4-4 due to dispersion in a narrow zone and weak wind environment. On the other hands, the lowest average concentration appeared P1 and P2 due to rapid dispersion to the sea. The simulated $^{137}Cs$ concentrations and dispersion locations of each local wind pattern are different according to the local wind conditions.

Multiple Linear Regression Model for Prediction of Summer Tropical Cyclone Genesis Frequency over the Western North Pacific (북서태평양 태풍발생빈도 예측을 위한 다중회귀모델 개발)

  • Choi, Ki-Seon;Cha, Yu-Mi;Chang, Ki-Ho;Lee, Jong-Ho
    • Journal of the Korean earth science society
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    • v.34 no.4
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    • pp.336-344
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    • 2013
  • This study has developed a multiple linear regression model (MLRM) for the seasonal prediction of the summer tropical cyclone genesis frequency (TCGF) over the western North Pacific (WNP) using the four teleconnection patterns. These patterns are representative of the Siberian high Oscillation (SHO) in the East Asian continent, the North Pacific Oscillation (NPO) in the North Pacific, Antarctic oscillation (AAO) near Australia, and the circulation in the equatorial central Pacific during the boreal spring (April-May). This statistical model is verified by analyzing the differences hindcasted for the high and low TCGF years. The high TCGF years are characterized by the following anomalous features: four anomalous teleconnection patterns such as anticyclonic circulation (positive SHO phase) in the East Asian continent, pressure pattern like north-high and south-low in the North Pacific, and cyclonic circulation (positive AAO phase) near Australia, and cyclonic circulation in the Nino3.4 region were strengthened during the period from boreal spring to boreal summer. Thus, anomalous trade winds in the tropical western Pacific (TWP) were weakened by anomalous cyclonic circulations that located in the subtropical western Pacific (SWP) in both hemispheres. Consequently, this spatial distribution of anomalous pressure pattern suppressed convection in the TWP, strengthened convection in the SWP instead.

Experimental Study on the Effective Temperature Calculation of Concrete Box Girder Bridge (콘크리트 박스거더교의 설계 유효온도 산정을 위한 실험적 연구)

  • Lee, Seong-Haeng
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.740-745
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    • 2020
  • To calculate the reasonable design temperature load of a concrete box girder bridge, one bridge test specimen was made. The temperature gauges installed on the bridge test specimen measured 48 sets of temperature per day at 30-minute intervals during the summer and winter periods of one year. The temperature measured at each station was treated statistically to calculate the trend line and standard error, and the temperature distribution and trend line at the representative station were presented. The maximum effective temperature and the lowest effective temperature were calculated from the air temperature suggested by Euro code. The maximum effective temperature was calculated to be 1.5 to 2℃ higher than the Euro code at 35℃ and above. In comparison, the lowest effective temperature was 0.5 to 1.1℃ lower at -13℃ to-19℃. Compared to the effective temperature of this study according to the highest and lowest 50-year frequency of the Yangsan region, the highest effective temperature was 4.7℃ higher, and the lowest effective temperature was 4.5℃ lower. Considering the increasing climate change and reflecting the results of this analysis, it is deemed necessary to make the current temperature design standards larger.