• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.103-109
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• 2007

To investigate the effects of artificial vegetation island (AVI) on fish distribution, we compared fish fauna from artificial vegetation island (AVI) area, which installed in 2000, natural vegetation area (NVA) and vegetation-free area (VFA) at Kyungan Stream area of Lake Paldang from Jul. to Nov., 2005. Results showed that 11 families 23 genera 24 fish species were distributed in the AVI and NVA. Squalidus japonicus coreanus, a small-size fish which generally lives at the downstream, dominated absolutely in the individual numbers. However, only 6 families 11 genera 12 species of fishes caught at the VFA, and dominant fishes were Hemibarbus labeo and Erythroculter erythropterus, a medium to large-size migratory fishes which live in mid-depth of water column. The dominance index was high at the AVI (0.778) and NVA (0.868), whereas the diversity index and evenness index were high at the VFA. Fish distribution at AVI was similar to that of the NVA in numbers of species, indicating that the AVI could playa role as spawning and inhabitation zone to a variety of fishes. We believe that AVI may be used for a restoration of the damaged and disturbed littoral ecosystem.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.117-122
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• 1990

The Jido Pond system was investigated from April, 1979 through March, 1980, in respect of seasonal changes in physico-chemical factors: i.e., temperature, pH, DO, BOD, COD, $Cl^-, \; Mg^{++}$, alkalinity, detergent, $SiO_2, PO_4\;^{3-}, NH_4\;^+, NO_2\;^-, NO_3\;^-$, total N, OM and OC; phytoplankton community growth; and the ecosystem metabolism. The phytoplankton community was represented by 23 species belonging to Chlorophyta, Bacillariophyta and Cyanophyta; each sharing 11, 9 3 respectively. The Chlorophyceans dominated the phytoplankton community contributing 75% of the total ？미 counts. The ranges of biotic diversity indices were, d, 0.85~2.80; H, 1.10~2.40; c, 0.13~0/40; and 3, 0.56~0.90. The chlorophyll standing crop varied in between 0.043 and 0.385g/$\textrm{cm}^2$ surface area. The ranges of photosynthetic and respiratory rates were 0.36~4.50; and 0.10~1.40 $O_2$ mg/1/hr, respectively. The monthly areal net primary production varied from 23.9 to 305.1C g/$\textrm{m}^2$/month. The Eu of the net production seasonally varied in between 0.31 and 7.80%, and the annual mean was 2.44%. The annual turnover times of phosphorus and nitrogen were 20 and 3 days, respectively.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1087-1093
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• 2005

The population diversity and seasonal changes of bacterial communities in rice soils were monitored using both culture-dependent approaches and molecular methods. The rice field plot consisted of twelve subplots planted with two genetically-modified (GM) rice and two non-GM rice plants in three replicates. The DGGE analysis revealed that the bacterial community structures of the twelve subplot soils were quite similar to each other in a given month, indicating that there were no significant differences in the structure of the soil microbial populations between GM rice and non-GM rice during the experiment. However, the DGGE profiles of June soil after a sudden flooding were quite different from those of the other months. The June profiles exhibited a few intense DNA bands, compared with the others, indicating that flooding of rice field stimulated selective growth of some indigenous microorganisms. Phylogenetic analysis of l6S rDNA sequences from cultivated isolates showed that, while the isolates obtained from April soil before flooding were relatively evenly distributed among diverse genera such as Arthrobacter, Streptomyces, Terrabacter, and Bacillus/Paenibacillus, those from June soil after flooding mostly belonged to the Arthrobacter species. Phylogenetic analysis of 16S rDNA sequences obtained from the soil by cloning showed that April, August, and October had more diverse microorganisms than June. The results of this study indicated that flooding of rice fields gave a significant impact on the indigenous microbial community structure; however, the initial structure was gradually recovered over time after a sudden flooding.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.10a
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• pp.119-136
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• 2002

Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. During the Daebo igneous activities (c.a. 200-150 (?) Ma) coincident with orogenic time, gold mineralization took place between c.a. 195 and 135 (127 ?) Ma. The Jurassic Au deposits commonly show several characteristics; prominent association with pegmatites, low Ag/hu ratios in the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, arsenopyrite, Au-rich electrum, pyrrhotite and/or pyrite. During the Bulgugsa igneous activities $(110\~50Ma)$, the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high AE/AU ratios in the ore concentrates, and diversity of ore minerals including base-metal sulfides, pyrite, arsenopyrite, Ag-rich electrum and native silver nth Ag sulfides, Ag-Sb-As sulfosalts and Ag tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems in Korea. The Jurassic Au-dominant deposits (orogenic type) were formed at the relatively high temperature $(about\;300^{\circ}\;to\;450^{\circ}C)$ and deep-crustal level $(4.0{\pm}1.5\;kb)$ from the hydrothermal fluids containing more amounts of magmatic waters $(\delta\;^{18}O_{H2O}\;5\~10\%_{\circ})$. It can. It can be explained by the dominant ore-depositing mechanisms as $CO_2$ boiling and sulfidation, suggestive of hypo- to mesothermal environments. In contrast, the Cretaceous Au-dominant $(l13\~68\;Ma),\;Au-Ag \;(108\~47\;Ma)$ and Ag-dominant $(103\~45\;Ma)$ deposits, which correspond to volcanic-plutonic-related type, occurred at relatively low temperature $(about\;200^{\circ}\;to\;350^{\circ}C)$ and shallow-crustal level $(1.0\{pm}0.5\;kb)$ from the ore-forming fluids containing more amounts of less-evolved meteoric waters$(\delta\;^{18}O_{H2O}\;-10\~5\%_{\circ})$. These characteristics of the Cretaceous precious-metal deposits can be attributed to the complexities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epi- to mesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit styles.

• Korean Journal of Environment and Ecology
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• v.13 no.4
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• pp.340-347
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• 2000

지리산국립공원의 쌍계사지의 불일폭포-성불재 계곡부(해발 600-1.1200m)의 해발고와 사면부위에 따른 교목층의 산림구조를 조사하기 위하여 해발고와 사면부위에 따라 42개 조사구를 설정하였다 교목상층의 밀도 평균흉고직경 흉고단면적의 범위는 각각 545-1,700본/ha 11.0-23.5cm, 19.1-27.8m2/ha 이었다 교목상층의 평균흉고직경과 흉고단면적 교목층 전체의 흉고단면적은 계곡중부에서 가장컸다 해발고가 높아짐에 따라 중요치가 증가하는 경향을 보이는 수종은 신갈나무 소나무 등이었으며 감소하는 수종은 굴참나무 졸참나무, 비목나무 등이었다 사면하부에서 상부로 갈수록 중요치가 증가하는 수종은 굴참나무 쇠물푸레 철쭉꽃 등이었으며 감소하는 수종은 노각나무 비목나무 느티나무 당단풍 때죽나무 등이었다 해발고와 사면부위가 높을수록 종수와 종다양도는 감소하였으며 해발고대별 종다양도는 0.626-1.320 의범위를 보였다 계곡정부를 제외한 해발고대간 유사도지수는 36.1-60.6% 사면부위간 유사도지수는 59.2-74.4% 로서 사면부위보다 해발고에 따른 종구성 상태의 차이가 심한 것으로 나타났다 수종별 중요치에 의한 Cluster 분석결과 계곡하부의에 위치한 서어나무-활엽수군집 계곡상부의 사면중 하부에 위치한 신갈나무-활엽수군집 계곡정부와 계곡상부의 사면상부에 위치한 신갈나무-소나무군집 등 4개 유형군집으로 구분되었다 종상관 분석결과 소나무 신갈나무 쇠물푸레 철쭉꽃 등 4개 수종간 비목나무 산뽕나무 생강나무 등 3개 수종간에는 유의적인 정의 상관이 있었다. 신갈나무, 쇠물푸레 철쭉꽃 등은 졸참나무와 소나무 쇠물푸레 등은 비목나무 서어나무와 유의적인 부의 상관이 있었다.증가에 따라 250 g/L까 지 증가하여 최대 51.0%의 수율과 0.63 g/L-h의 생산성을 나타내었다. 얻을 수 있었다. 따라서 이 방법이 일단 생산성 향상을 위한 세포의 고농도 배양에는 조사한 여러 배양 시스템 중에 가장 효율적인 시스템임올 알 수 있었다 하지만 이 시스템 에서 포도당을 낮은 level로 유지할 수 있었으나, 초산의 과도한 축적으로 항체 생산성의 향상은 예상에 비해 크지 않았다. 81%), C18 0(12.38%), C18: 1(25.93%), C22:6(9.95%)이며 결합지방질(結合脂肪質)은 C14 : 0(11.60%), C16 : 0(18.94%), C16: 1(10.42%). C18 : 1(10.89%), C22 : 6(23.44%)이었다. 총필수지방산(總必須脂肪酸) 함량(含量)은 극성지방질(極成脂肪質)$(20.14{\sim}31.12%)$이 비극성지방질(非極成脂肪質)$(6.97{\sim}11.13%)$보다 훨씬 높았고, 결합지방질(結合脂肪質)이 유리지방질(遊離脂肪質)보다 높았으며 부위별(部位別)로는 피부(皮部)$(15.18{\sim}15.41%)$가 육질부(肉質部)$(6.97{\sim}11.13%)$보다 높았다. 또${\omega}3$고도부포화지방산(高度不飽和脂肪酸) 함량(含量)은 육질부(肉質部)$(15.15{\sim}28.32%)$가 피부(皮部)$(6.77{\sim}18.18%)$나 내장부(內臟部)$(8.35{\sim}9.74%)$보다 높았으며, 육질부(肉質部)에서는 극성지방질(極成脂肪質)

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.18-27
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• 2012

This paper proposes a management method for a coastal black pine forest landscape considering the parallax effect. For the study, 10 coastal black pine forests in Gangneung were investigated about the average width of the coastal forests, the average diameters, and the intervals of the pines. Categorizations were realized for the 3 types of scene(sea, field, mountain, residential area, commercial area), diameter(16cm, 22cm, 28cm) and interval(5m, 7m, 10m) to produce a total of 45 scenic simulations. An investigation was made on the scenic preferences using 45 simulation images with S.D, and Likert Scales. The results were as follows: According the comparison of scenic preferences, natural landscapes(sea, field, and mountain) ranked high among preferences, with fabricated landscapes(residential area, commercial area) ranked low. The highest scenic preferences were shown with the seascape and an interval of 7m between the trees. On the contrary, the interrelationship was very low between the visual quantity of the scenic's elements(green, sky, building, road etc.) and the scenic preferences. As the results of the factor analysis, the 3 sense factors of "Depth(78.0%)" "Diversity(l5.6%)" and "Spatiality(6.4%)" explained coastal scenic preferences. "Spatiality" showed significant differences at intervals of 5~7m, and 10m between trees. This shows coastal forest management based on the interval of 10m standard affecting scenic preference.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.2
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• pp.24-31
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• 2008

Studies for demarcation of urban areas by ecological type have been developed, but the demarcation of urban areas by ecological perception is thus far dependent on artificial land use. Therefore, the purpose of this study is to find factors that account for the urban area ecosystems by surveying a variety of ecosystem factors. By land use type, the urban area of Gangdong District, Seoul was defined. Then ecological factors in each polygon were surveyed. Ecological factors are associated with energy use(building coverage ratio, floor area ratio and ground temperature), water circulation(biotope area factors and impermeable pave ratio) and biological diversity(bird appearance index and green area ratio). The correlation between each factor was analyzed. The results indicate that urban ground temperature is divided into three groups(high, middle and low) by the biotope area factor. The bird population is divided into two groups(abundant and scarce) by the green area ratio. Therefore, demarcating the urban areas by ecological type is applicable to the biotope area factor and green area ratio.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.77-82
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• 2006

Annual bluegrass(Poa annua L.) is a problem weed that is very difficult to control on golf courses. There are some reasons that make Poa annua such a difficult weed to be controled. One of these reasons is this plant's ability to reproduce its seed even under stressful conditions. Another reason is its adaptation to low mowing heights. Above all things, the greatest competitive advantage of Poa annua is its genetic diversity. Generally, Poa annua is a bunch type and annual type cool-season grass, but some types act as weak perennials and have stolons. There has been much research on controlling annual bluegrass in golf course turf with chemical and cultural techniques. This research has been conducted for more than 85 years. There has been some progress in controlling some types of Poa annua, but these methods have not been successful on every biotype. Among all of the techniques, Roundup ready creeping bentgrass has the most promise of controlling the diverse types of Poa annua. Roundup ready bentgrass is capable of tolerating the effects of Roundup(glyphosate) while it kills other plants including Poa annua. By using this new technology, we can make Poa annua free greens, tees, and fairways.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.404-416
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• 2020

Studies on the preservation and propagation of tropical and subtropical plants are required, but the studies are insufficient in Korea. Since 2013, the Tropical Plant Resources Research Center has been collaborating on field research and publication to preserve plant diversity in Myanmar protected areas and Sagging areas in cooperation with Ministry of Natural Resources and Environment Conservation and the Myanmar Forest Research Institute. This study is to provide information on cooperative projects. As a result of the joint research between the Korea National Arboretum and Myanmar, in December 2018, the Korea National Arboretum Tropical Plant Resources Research Center is on display for conservation and education purposes with the 65 Myanmar useful materials and specimens of 326 kinds of plants and specimens that Myanmar Forest Research Institute donated. This donation is the first case of Myanmar's export of plant organisms to a foreign country, and as for the Korea National Arboretum, it is the second official case of introducing a mass plant from foreign governments. The study will also accelerate preservation biodiversity and propagation methods of tropical and subtropical plants as well as research on biodiversity conservation and industrial use.

• Korean Journal of Head & Neck Oncology
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• v.14 no.1
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• pp.40-45
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• 1998

Backgroud and Objectives: Major salivary gland tumor is a rare disease with a largely unknown origin. And also corresponding to the diversity of histopathologic characteristics is an equally wide distribution of clinical behavior that makes treatment decisions difficult. The aim of this study is to analysis the clinical experience of our major salivary gland tumor and to suggest a guidline of management. Materials and Methods : We studied clinical manifestations and treatment results of 104 patients who were diagnosed as major salivary gland tumors. Tumor site, patient age and sex of the patients were analysed. Histopathologic diagnosis, treatment modality, lymph nodes metastasis, recurrence rate and 5-year survival rate were studied on malignant tumors. Results: 1) 48 patients were male and 56 patients were female. 2) Benign tumors were 79 cases. They consisted of 57 cases(72%) of parotid tumor, 22 cases(27%) of submandibular tumor. And pleomorphic adenoma was the most common benign tumor. 3) Malignant tumors were 25 cases and were consisted of 19 cases(76%) of parotid tumor, 4 cases(l6%) of submandibular tumor and 2 cases(8%) of sublingual gland tumor with high-grade mucoepidermoid carcinoma as the most common cause. 4) In the malignant tumors, the number of stage I, II tumors was 14 and that of stage III, IV tumors was 11. Neck node metastasis was noted in 8 cases. 5) 8 cases of malignant tumor were died and all of them had high-grade malignancy. And they were dead before 17 months from the time of diagnosis. 6) Mean survival duration in the malignant salivary gland tumor was 56 months. 7) High-grade malignancy had a 5-year survival rate of 57.9%. A 5-year survival rate of TI, T2 patients was 92.9% and that of T3, T4 patients was 36.4%. That of patients who had neck node metastasis was 37.5% and that of those who had tree neck was 82.4%. Conclusion: The results of this study suggest that the survival rate is dependent on the tumor size, lymph node matastasis and histologic grade. And also the early diagnosis and radical surgery result in the increased survival rate and are effective for prevention of the tumor recurrance.