• Title/Summary/Keyword: Jeju area

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Community Structure and Health Assessment of Macrobenthic Assemblages during Spring and Summer in the Shellfish Farming Ground of Wonmun Bay, on the Southern Coast of Korea (원문만 패류양식어장에 서식하는 대형저서동물의 춘계와 하계의 군집구조 및 건강도 평가)

  • Jung, Rae Hong;Seo, In-Soo;Choi, Minkyu;Park, Sang Rul;Choi, Byoung-Mi;Kim, Mi Hyang;Kim, Yeon Jung;Yun, Jae Seong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.908-926
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    • 2014
  • This study investigated the community structure and health assessment of macrobenthic assemblages in Wonmun Bay, in the southern coast of Korea. The total number of species and mean density were 170 species and $1,269\;indivuduals/m^2$, respectively. The major dominant species were the bivalve Theora fragilis ($230{\pm}446\;indivuduals/m^2$) and the polychaetes Lumbrineris longifolia ($180{\pm}339\;indivuduals/m^2$), Sigambra tentaculata ($124{\pm}153\;indivuduals/m^2$), Paraprionospio patiens ($104{\pm}293\;indivuduals/m^2$) and Capitella capitata ($82{\pm}223\;indivuduals/m^2$). Community statistics [cluster analysis and nonmetric multidimentional scaling (NMDS) ordination] revealed that the macrobenthic community structure in the study area was classified into three station groups for both seasons. Several biotic indices based on macrobenthic communities have been developed to assess the ecological quality of coastal ecosystems. In this study, the ecological status was assessed by four biotic indices Shannon's H', the AZTI Marine Biotic Index (AMBI), multivariate-AMBI (M-AMBI) and the Ecological Conservation Index (ECI). The ecological statuses of the macrobenthic communities in Wonmun Bay were poorer in the summer than in the spring. The results of the present study indicate that three biotic indices ( i.e.; Shannon's H', M-AMBI and ECI ) were better correlated with bottom dissolved oxygen than the AMBI in Wonmun Bay.

Future Projections on Subtropical Climate Regions over South Korea Using SRES A1B Data (A1B 시나리오 자료를 이용한 우리나라 아열대 기후구 전망)

  • Kwon, Young-Ah;Kwon, Won-Tae;Boo, Kyung-On;Choi, Young-Eun
    • Journal of the Korean Geographical Society
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    • v.42 no.3 s.120
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    • pp.355-367
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    • 2007
  • As the global warming has been influenced on various sectors including agriculture, fisheries and health, it is essential to project more accurate future climate for an assessment of climate change impact and adaptation strategy. The purpose of this study is to examine the boundary changes in the subtropical climate region in South Korea using observed 30-year(1971-2000) data and projected 100-year data based on the IPCC SRES A1B emission scenario. We have selected Trewartha's climate classification among various climate classification, defining the subtropical climate region as the region with monthly mean temperature $10^{\circ}C$ or higher during 8-12 months. By observed data, the subtropical climate region was only limited in Jeju-do and the farmost southern coastal area(Busan, Tongyeong, Geoje, Yeosu, Wando, Mokpo) of South Korea. The future projected climate region for the period of 2071-2100 included have shown that subtropical climate region extended to most of stations except for the ares of Taebaeksan and Sobaeksan Mountains.

Vegetation Structure of the Torreya Nucifera Stand in Korea (한반도 비자나무림의 식생구조)

  • Shin, Hyun-Cheol;Lee, Kwang-Soo;Park, Nam-Chang;Jung, Su-Young
    • Journal of Korean Society of Forest Science
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    • v.99 no.3
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    • pp.312-322
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    • 2010
  • In Korea, Torreya nucifera (L.) Siebold & Zuccarini is widely distributed in the warm temperate zone of South coastal area and Jeju island, mainly as preserved forest in the vicinity of the Buddhist temple and Confucian temple. The objective of this study is in order to develop the conservation method and comprehension of vegetation community by current vegetation structure analysis of Torreya nucifera stand. As the results, the number of surveyed species in Torreya nucifera stand were total 148 species with 28 species of tree layer, 38 species of subtree layer, and 82 species of shrub layer. The appearance of the common species were Ligustrum obtusifolium Siebold & Zucc., Hedera rhombea Bean, and Trachelospermum asiaticum Nakai var. asiaticum. All the story of the surveyed region, Torreya nucifera maintained the current dominant species, but the subtree layer and shrub layer was decreased dominant rate because of the development of the crown of tree layer and biased growth of the subtree layer. Most of the tree layer and subtree layer in Torreya nucifera stands are composed of the sprout forest. Therefore, these results suggest that in order to maintain the healthy stand it is demanded for the application of selection thinning method for reducing crown competition in Torreya nucifera forests.

The Spread of Black Pine Bast Scale, Matsucoccus thunbergianae (Hemiptera: Margarodidae) in Korea (우리나라에서 솔껍질깍지벌레의 분포확산)

  • Lim, Eu-Gene;Lee, Sang-Myeong;Kim, Dong-Soo;Kim, Joon-Bum;Lee, Shin-Hye;Choi, Kwang-Sik;Park, Chung-Gyoo;Lee, Dong-Woon
    • Korean journal of applied entomology
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    • v.51 no.1
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    • pp.59-65
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    • 2012
  • The black pine bast scale, $Masucoccus$ $thunbergianae$ (Hemiptera: Margarodidae), is a serious pest of the Japanese black pine, $Pinus$ $thunbergii$, in Korea. The distribution of the black pine bast scale was examined, looking overall at 686 towns (eup), townships (myeon) or neighborhoods (dong). There were Japanese black pine ($Pinus$ $thunbergii$) forests in 91 cities, counties (gun) and borough (gu), in seven provinces and three metropolitan cities during 2010. Black pine bast scale were found in 64.8% of cities or counties or borough (59) in 7 provinces and 3 metropolitan cities, and were distributed in all South Costal regions, Pohang in East Costal region and Boryeong in West Costal region. Chungcheongbukdo, Daejeon and Jeju did not have black pine bast scale. All the gu regions in Busan had black pine bast scale, of which the area with the highest prevalence was Haenam in Jeollanamdo (1.713 crawlers/0.785 $cm^2$). Songji-myeon had the highest occurrence rate (6.36 crawlers/0.785 $cm^2$) from the towns, township and dong. The density of black pine bast scale in twigs was highly correlated with percentage of the sample with scale (Correlation coefficacy=0.89).

Atmospheric Dispersion Characteristics of Radioactive Materials according to the Local Weather and Emission Conditions

  • An, Hye Yeon;Kang, Yoon-Hee;Song, Sang-Keun;Kim, Yoo-Keun
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.315-327
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    • 2016
  • Background: This study evaluated the atmospheric dispersion of radioactive material according to local weather conditions and emission conditions. Materials and Methods: Local weather conditions were defined as 8 patterns that frequently occur around the Kori Nuclear Power Plant and emission conditions were defined as 6 patterns from a combination of emission rates and the total number of particles of the $^{137}Cs$, using the WRF/HYSPLIT modeling system. Results and Discussion: The highest mean concentration of $^{137}Cs$ occurred at 0900 LST under the ME4_1 (main wind direction: SSW, daily average wind speed: $2.8ms^{-1}$), with a wide region of its high concentration due to the continuous wind changes between 0000 and 0900 LST; under the ME3 (NE, $4.1ms^{-1}$), the highest mean concentration of $^{137}Cs$ occurred at 1500 and 2100 LST with a narrow dispersion along a strong northeasterly wind. In the case of ME4_4 (S, $2.7ms^{-1}$), the highest mean concentration of $^{137}Cs$ occurred at 0300 LST because $^{137}Cs$ stayed around the KNPP under low wind speed and low boundary layer height. As for the emission conditions, EM1_3 and EM2_3 that had the maximum total number of particles showed the widest dispersion of $^{137}Cs$, while its highest mean concentration was estimated under the EM1_1 considering the relatively narrow dispersion and high emission rate. Conclusion: This study showed that even though an area may be located within the same radius around the Kori Nuclear Power Plant, the distribution and levels of $^{137}Cs$ concentration vary according to the change in time and space of weather conditions (the altitude of the atmospheric boundary layer, the horizontal and vertical distribution of the local winds, and the precipitation levels), the topography of the regions where $^{137}Cs$ is dispersed, the emission rate of $^{137}Cs$, and the number of emitted particles.

Effects of Low Temperature on the Development of Greenhouse White Fly, Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae) (온실가루이의 저온장애에 관한 연구)

  • Choe Kwang-Ryul;Park Joong-Soo
    • Korean journal of applied entomology
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    • v.22 no.4 s.57
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    • pp.233-236
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    • 1983
  • Results obtained from the experiment conducted to determine the potential distribution of greenhouse white flies are summerized as follows; Hatching rate of eggs were significantly decreased when eggs were treated under $-5^{\circ}C$ for three days and no eggs were hatched when 4he eggs were treated at $10^{\circ}C$. for three days. Kate of pupation was also decreased when larvae were subjected to $-5^{\circ}C$ for three days and no pupation of larvae was of served when the larvae were under $-20^{\circ}C$ for three days. Emergency rate of pupae was decreased when pupae were under $-20^{\circ}C$. for three days and no emergence was observed when pupae were treated at the temperature of $-20^{\circ}C$ for three days. Survival rate of adults were greatly decreased when they were under $-7.5^{\circ}C$. for three days and the adults were completely dead when they were subjected to $-10^{\circ}C$. for three days. Therefore, it may be concluded that the greenhouse white flies may be overwintered, in the from of pupae at the middle-southern part of Korea, while they may overwinter in all developmental stages in Jeju Island and in southern tip coast area of Korea.

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Low Frequency Fluctuation Component Analysis in Active Stimulation fMRI Paradigm (활성자극 파라다임 fMRI에서 저주파요동 성분분석)

  • Na, Sung-Min;Park, Hyun-Jung;Chang, Yong-Min
    • Investigative Magnetic Resonance Imaging
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    • v.14 no.2
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    • pp.115-120
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    • 2010
  • Purpose : To separate and evaluate the low frequency spontaneous fluctuation BOLD signals from the functional magnetic resonance imaging data using sensorimotor active task. Materials and Methods : Twenty female archery players and twenty three control subjects were included in this study. Finger-tapping task consisted of three cycles of right finger tapping, with a subsequent 30 second rest. Blood oxygenation level-dependent (BOLD) data were collected using $T2^*$-weighted echo planar imaging at a 3.0 T scanner. A 3-D FSPGR T1-weighted images were used for structural reference. Image processing and statistical analyses were performed using SPM5 for active finger-tapping task and GIFT program was used for statistical analyses of low frequency spontaneous fluctuation BOLD signal. Results : Both groups showed the activation in the left primary motor cortex and supplemental motor area and in the right cerebellum for right finger-tapping task. ICA analysis using GIFT revealed independent components corresponding to contralateral and ipsilateral sensorimotor network and cognitive-related neural network. Conclusion : The current study demonstrated that the low frequency spontaneous fluctuation BOLD signals can be separated from the fMRI data using finger tapping paradigm. Also, it was found that these independent components correspond to spontaneous and coherent neural activity in the primary sensorimotor network and in the motor-cognitive network.

A Survey on Insect Diversity of Mulyeongari-Oreum Wetland, on Jeju Island, South Korea (제주도 물영아리오름 습지의 곤충다양성에 관한 연구)

  • Cho, Young-Ho;Han, Yong-Gu;Park, Seong-Joon;Park, Young-Jun;Kim, Young-Jin;Choi, Min-Joo;Nam, Sang-Ho
    • Korean Journal of Environment and Ecology
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    • v.25 no.4
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    • pp.526-539
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    • 2011
  • The purpose of this study is to identify insects inhabiting Mulyeongari-Oreum wetland and to provide basic information for conservation of wetlands. As a result, a total 229 species, 73 families, 9 orders of insects were collected: 136 species, 39 families, 6 orders from Mulyeongari-Oreum Wetland and 121 species, 52 families, 9 orders from Mt. Sooryeong. Of the 229 species of insects investigated, Copris tripartitus Waterhouse, an endangered species of wildlife fauna in Korea, was found with many individuals. Also, Lychnuris rufa(Olivier), having a narrow habitat near unpolluted water and mountains, was also recorded with 3 individuals and then should be considered as a protected species in Wetlands. To identify the community structure of moth on Mulyeongari-Oreum wetland, a light trap was examined and a total 76 species of moths were collected. Total dominant species was Hydrillodes morosa(Butler) with index of 0.12 and the species diversity on the moth community from survey area was the highest in July with index of 3.42.

Characteristics of Marine Litters Distribution on the Sea-bed of the East China Sea (동중국해의 해저 폐기물 분포특성)

  • Jeong, Sun-Beom;Lee, Dae-In;Cho, Hyeon-Seo;Kim, Young-Joo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.8 no.4
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    • pp.220-226
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    • 2005
  • This study evaluated the composition and distribution of marine litters on the sea-bed of the East China Sea. Surveys have been conducted by a benthic trawlnet of Dong-baek training ship of Yosu national university during the cruise of 2002-2004. Distribution density showed high value in C5 (north-western area of Jeju Island) with $110.3kg/km^2$ and those of annual mean were about $31-43kg/km^2$. Fishing gears such as nets, pots, octopus jars and etc. were about 42-72% of debris collected in the East China Sea. Composition ratio of rubber, vinyl. metal, plastic, glass, wood, cloth and etc. were within 25% except C5. Rope and drum showed strong fluctuations with 0-30% according to the trawling sites. Some vinyls and nets made in Korea, China and Japan were much collected. It is estimated that fishing gears were discarded to the sea by fishing operation, deliberately or not. An comprehensive program including continuous research, monitoring for marine litters in the Korean sea were necessary.

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A Study on Regional Competitiveness of the Part Material Industry (소재·부품산업의 지역경쟁력 분석)

  • Kim, Dae-Jung;Ko, Kyoung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.401-408
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    • 2020
  • The purpose of this study to analyze the regional competitiveness of the part material industry in Korea. According to the analysis, there was an empirical regional difference in the part material industry in Korea: in the Seoul Metropolitan Area, the industrial scale was found to be relatively small, although many companies were observed to be in the growing stage; in the Chungcheong region, it was estimated that the industrial scale is large, and many companies were found to have already reached the maturation stage with high growth rates; and in Honam and Jeju, Daekyung and Gangwon, and Dongnam, although the scale of the part material industry was found to be large, many companies were observed to be in the declining stage with low growth rates. This study also conducted an analysis based on LQ (Location Quotient) and RLQ (Relative efficiency of Labor Quotient). The analysis showed that industrial policies regarding workforce planning and industrial restructuring should focus on improving the productivity of the entire part material industry. Lastly, this study examined the competitive part material industry for the five regions by analyzing the RCC (Regional Competition Component). The findings of this study will be helpful in exploring ways to support the domestic part material industries in each region.