• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.243-274
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• 2013

To investigate the research state and characteristics of dinoflagellate cyst along the Korean coastal waters, this work analyzed 45 studies conducted in the Korean coasts and basin, the south of Jeju, East China Sea including some part of the Yellow Sea. It was found that the research on dinoflagellate cyst began in the later half of the 1980s in Korea, and that the research areas focused on eutrophied regions where a red tide occurred or on the seas where coastal development occurred. In other words, no research on the East Sea was found. In terms of research contents, there were various studies on analysis of cyst assemblage, tracking of the changes in marine environment like process of eutrophication, roles as a seed population in occurrence of a red tide, creation of cyst by use of sediment trip and tracking of its changes, morphological changes by the change of pH concentration in the hypoxia zone of eutrophied region, germination of a specific species, and other international-level studies. Species composition and cell density also varied in the Korean coastal waters. However, much research on dinoflagellate cyst in Korea is not systematic, and is fragmentary and individual and hencesuffers from great limitations. The research results so far have focused only on specific regions, and sporadic research had been conducted by specific research groups. Dinoflagellate cyst of surface sediments represents the accumulation index of pelagic environment in the sea and is a useful index to understand the marine environment efficiently. In conclusion, Korea requires organized human resources and collaborative research on dinoflagellate cyst which in turn should be considered as a component of marine ecosystem and as an essential aspect of marine biology.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.60-60
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• 2022

우리나라에 분포하는 팥꽃나무과(Thymelaeaceae) 산닥나무속(Wikstroemia) 식물은 산닥나무[Wikstroemia trichotoma (Thunb.) Makino], 거문도닥나무[W. ganpi (Siebold & Zucc.) Maxim.] 2종이 분포하고 있다. 산닥나무는 낮은 산지의 그늘진 계곡에서 주로 자생하며, 거문도닥나무는 임연부에서 주로 자생하는 것으로 알려져 있다. 현재 우리나라에 남아있는 자생지는 기후변화, 남획 등을 이유로 과거에 비하여 축소되어 유전자원의 현지 내·외 보전이 적극적으로 권장된다. 따라서 본 연구에서는 삼지닥나무, 산닥나무, 거문도닥나무의 생육환경 특성을 파악하여 보존 및 증식을 위한 기초자료로 활용하는 데 그 목적이 있다. 연구 결과, 확인된 자생지는 3지역 7개소로 산닥나무는 순천지역, 영암지역, 거문도닥나무는 고흥지역에 자생하는 것으로 확인되었다. 산닥나무는 해발고도 72-248 m, 사면 방위는 북사면, 동사면, 경사는 30-55°의 급경사지에서 주로 자생하는 것으로 확인되었으며, 방형구(10×10 m) 내 개체수는 8-20 개체가 확인되었다. 거문도닥나무는 해발고도 65-76 m, 사면방위는 동사면, 경사는 20-60°, 개체수는 15-25 개체가 확인되었다. 군집분석은 지표종 분석을 통해 가장 유의한 2개 군집으로 나뉘었으며, 산닥나무는 소나무 군집(Pinus densiflora Sieblod & Zucc.), 거문도닥나무는 곰솔(Pinus thunbergii Parl.) 군집으로 확인되었다. 군집의 안전성, 다양성을 나타내는 척도인 종다양성, 최대종다양도, 균재도 및 우점도지수는 소나무 군집 1.2303, 1.2788, 0.9621, 0.0389, 곰솔 군집이 1.1821, 1.2359, 0.9552, 0.0448로 확인되었다.

• Journal of Life Science
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• v.23 no.7
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• pp.933-940
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• 2013

The aim of this work was to determine the chemical composition of essential oil from aerial partsof Mentha arvensis L. f. piperascens (MAO) and to evaluate the effect of its fragrant chemicals on electroencephalographic (EEG) activity of human brain. The MAO was obtained by supercritical $CO_2$ extraction. The maximum yield was 2.38% at conditions of $70^{\circ}C$ and 200 bar. There were 32 volatile chemicals with 6 alcohols (67.11%), 13 hydrocarbons (17.05%), 9 esters (11.50%), 2 ketones (7.16%), 1 oxide (2.77%), and 1 aldehyde (0.56%). The major components were (Z,Z,Z)-9,12,15-octadecatrien-1-ol (50.06%), 2-hydroxy-4-methoxyacetophenone (7.50%), and 3,4-dihydro-8-hydroxy-3-methyl-1H-2-benzopyran-1-one (6.60%). Results of the EEG study showed that inhalation of MAO significantly changed the EEG power spectrum values of relative gamma, relative fast alpha, and spectral edge frequency 90%. During the inhalation of MAO, the value of relative fast alpha was significantly increased (p<0.05). On the other hand, the values of gamma and the spectral edge frequency 90% were significantly decreased (p<0.05). The present study suggests that fragrant chemicals of essential oil of M. arvensis reduce the level of mental stress and that they could be used in the treatment of psychophysiological disorders.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.23-28
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• 2003

In order to identify plant species and communities characteristic of lithospheric condition, forest vegetations of igneous(mainly granite) and sedimentary(mainly sandstone) areas in Kyungpook province were compared. We collected 108 phytosociological releves from the older forests over 20 years old. 444 vascular plant species and 25 plant communities were identified. Results of Principal Coordinates Analysis (PCA) indicated that lithospheric conditions and human impacts were the most important factors related to the plant community diversity and species richness. In the igneous rock areas net contribution degree (rNCD) of 139 species including Quercus serrata, Q. mongolica, Lindera obtusiloba and Fraxinus sieboldiana increased and those of Carpinus laxiflora and Styrax japonica decreased. In the sedimentary rock areas, to a lesser extent, 96 species including Q. aliena, Zanthoxylum schinifolium, Potentilla fragarioides var. major, Rhus javanica, and Plectranthus japonicus increased, whereas character species of Lindero-Quercion mongolicae such as Q. mongolica, Q. serrata, Rhododendron schlippenbachii, Acer mono and Styrax obassia decreased, and particularily the species Sasa borealis, the Alangium-Zelkova serrata community and the Philadelphus-Fraxinus mandshurica community were absent. The vegetation of sedimentary rock area is characterized as a regional type shaping dwarf pine forests and sparse and light broad-leaved forests.

• The Korean Journal of Ecology
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• v.23 no.1
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• pp.51-57
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• 2000

Concentrations of cadmium, copper and zinc were determined in three molluscan species including Sacculosiphonaria japonica, Reishia clavigera and Crassostrea gigas to assess heavy metal contamination in the Onsan Bay. The range of cadmium concentrations were 3.83∼39.67 ㎍/g d.w. in S. japonica, 7.47∼103.47 ㎍/g d.w. in R. clavigera, 1.32∼92.17 ㎍/g d.w. in C. gigas. Concentration of cadmium at contaminated site in C. gigas was 70 folds higher than that of reference site. The range of copper concentrations were 22.92∼1287.56 ㎍/g d.w. in S. japonica, 37.53∼656.97 ㎍/g d.w. in R. clavigera, 161.50∼3208.52 ㎍/g d.w. in C. gigas. The concentration of copper at contaminated site in S. japonica was 56 folds higher than that of reference site. The range of zinc concentrations were 93.48∼377.40 ㎍/g d.w. in S. japonica, 423.65∼1075.57 ㎍/g w. in R. clavigera, 2018.13∼22275.00 ㎍/g d.w. in C. gigas. The difference of zinc concentrations between reference site and contaminated site was relatively small than those of cadmium and copper in all the species tested. The largest difference was 11 folds in C. gigas. In the present work, we confirmed that all of these species, S. japonica, R. clavigera and C. gigas, could be used as biological indicators to monitor heavy metal contamination.

• Spatial Information Research
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• v.20 no.3
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• pp.15-25
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• 2012

In order to resolve transportation system focused on vehicles which have led to all sorts of problems such as traffic congestion, air pollution and so on, Korea recently have tended to center around Transit Oriented Development(TOD) which is capable of initiating public traffic demands. It is imperative to develop objective evaluation method which is able to measure pedestrian environment and amenity in order to facilitate green transit. The purpose of this paper is to present evaluation indices and measurement framework of pedestrian environment by analyzing effect on TOD major planning factors such as diversity, density, design, and supply etc. For this, we applied evaluation index with regard to TOD planning factors, investigating connection to pedestrian and employed AHP (Analytic Hierarchy Process) so as to quantify the result of measurement in Jongro 3ga and Hangangjin station. As a result, we presented relationship between travel patterns of pedestrian and each TOD planning factor. More importantly, the proposed framework is expected to make the best of the visualization as well as evaluation method for the pedestrian accessibility, convenience of public transportation, and the mixed land-use patterns in subway area and transit center.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.245-252
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• 1990

The distributions of copepods and chaetognaths in waters off the southern coast of Korea were investigated to evaluate their reliability as indicator species of different water masses. The samples for this study were collected vertically from about 5m above the bottom at 28 stations along 8 transects in three different months, February, April, and August, 1988. The sampling gear used was 0.45-meter NORPAC plankton net fitted with 0.33mm mesh. Acartia clausi, Centropages abdominalis, and Sagitta crassa were found to be reliable indicator species of neritic cold waters; Pleuromamma gracilis, Undinula darwini, Calocalanus plumulosus, Calanopia elliptica, and Sagitta enflata were of oceanic warm waters; Temora discaudata and Centropages furcatus were of neritic warm waters. According to the cluster analyses of the species found, the distinctive area in February was divisible into two regions or water masses, the coastal and off-shore regions; in April, however, it was divisible into four regions. In August, it was divisible into three areas, further indicating the strength of the Kuroshio tributaries pushing toward the coast.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.318-327
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• 1987

Taxonomic composition and diversity were wxamined by statistical analysis for bacterial communities in surface waters of the Sudong Stream, a tributary of North Han River. For total 282 isolates, Flavobacterium, Aeromonas and Enterobacteriaceae was identified by the deterministic schemes as a major group above 50% of total isolates in all sampling sites. Morphological, biochemical and physiological characteristics were numerically analyzed for bacterial isolates from each site and clustered into 15-28 groups. Not all statistically clustered groups were identical to the groups derived from deterministic identification. Especially, consistent relationship was not found in dendrograms for the groups with each a single strain which gas peculiar sugar-degrading activity. At a level of 80% similarity, bacterial diversity (H) was ranged as 2.37-3.14, and it was suggested that the research area was oligotrophic-mesotrophic status. Regional distribution of bacterial community was most heterogeneous at the site where large input of allochthonous materials or bacteria were occurred. And that was the significant factor for the compositions of bacterial communities in the Sudong stream.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.5-11
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• 2014

In this study, chemical analysis and ecotoxicity tests of leachate from disposal site for foot-and-mouth disease carcasses (FMD leachate) were conducted to collect fundamental data that will be used to develop environmental risk assessment tools for FMD leachate. For chemical analysis, concentration of $Cl^-$, $NH{_4}{^+}-N$, Korea standard method indicators for detection of leachate released from animal carcasses burial site into groundwater and NRN (Ninhydrin-Reactive Nitrogens), a newly suggested screening test indicator to detect groundwater contamination by FMD leachate, were assessed. For ecotoxicity tests, luminescent bacteria (V. fischeri), micro-algae (P. subcapitata) and water flea (D. magna) were selected as test species. Correlation analysis between the concentration of $Cl^-$, $NH{_4}{^+}-N$, NRN and the toxicity to V. fischeri was performed to identify the better indicators to monitor FMD leachate contamination. From regression analysis, the concentration of the indicators in FMD leachate contaminated sample that induced halfmaximal toxic effect to V. fischeri was evaluated. Results obtained from this study can be applied to assess the risk by FMD leachate and to establish the guideline to manage risk in relation to FMD leachate.

• The Korean Journal of Malacology
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• v.12 no.2
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• pp.123-131
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• 1996

진해만 바위해안 조간대에 서식하는 뿔소라과 2종, 대수리(Thais clavigera)와 뿔두드럭고둥(T. luteostoma), 에서 수컷의 성징이 암컷에게서 발현되는 임포섹스 현상을 조사하였다. 임포섹스는 전 조사정점에서 100% 나타나고 있었으므로 본 조사에서 수컷의 성징을 보이지 않은 암컷은 발견할 수 없었다. 임포섹스의 강도를 나타내는 상대 성기 길이 지수(relative penislength index: RPL)는 34.7%에서 81.1%의 범위에 있었다. 특히 마산만 안쪽의 조사정점에서는 암컷의 구성비가 크게 감소하고 어린 개체를 거의 발견할 수 없는 등 개체군이 임포섹스의 영향을 받고 있음을 알 수 있었다. 두 종의 체내에 함유된 트리부틸주석(TBT)과 트리페닐주석(TPT)의 농도를 분석한 결과 각각 0.18-1.45 $\mu\textrm{g}$/g, 0.42-6.30 $\mu\textrm{g}$/g의 범위에 있었으며, 임포섹스의 정도는 트리부틸주석과 트리페닐주석의 체내 농도와 밀접한 관계를 보였다. s 대수리와 뿔두드럭고등의 임포섹스는 우리 나라에서 유기주석 화합물의 오염을 나타내는 좋은 지표로 사용될 수 있으며, TBT의 사용 규제이후 그 효과를 감시하기 위한 용도로도 유용하게 사용될 수 있다.