• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.1-21
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• 2024

This study conducted surveys to identify the distribution of communities and flora according to vegetation in the coastal sand dunes of Sagye in Jeju Special Self-Governing Province, located at the southernmost tip of Korea. The survey was conducted over 20 sessions from April 2020 to October 2021. As a result of the study, physiognomy was classified into six correlated vegetation types: plant communities on the salt marsh, annual communities on a coastal drift-line, herb communities on a dune, shrub communities on a coastal dune, forest-edge communities on a dune, and artificial afforestation vegetation. The survey identified 43 communities, and a total of 212 taxa were found to be distributed among 62 families, 166 genera, 191 species, 15 varieties, 3 subspecies, and 3 forma. It was found that there were five rare plant taxa distributed in the area, including the Cymbidium macrorrhizum which was classified as an endangered Class II plant by the Ministry of Environment. Floristic target species identified by the surveys included 2 taxa for grade V, 5 taxa for grade IV, 15 taxa for grade III, 14 taxa for grade II, and 19 taxa for grade I. Climate-sensitive biological indicator species included 11 indicator and 2 candidate species, representing a high ratio of 33.3% of all indicator species and 15.4% of candidate species. Naturalized plants included 16 families, 43 genera, and 52 taxa, with a naturalization rate of 21.1% and an urbanization index of 24.5%. It is expected that these results will be widely used as data needed to prepare conservation and management measures for biodiversity in response to climate change in coastal dunes in the future.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.411-418
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• 2015

Lonicera caerulea var. edulis is a rare species found in some alpine region of Korea. Genetic variation in L. caerulea var. edulis has been investigated by examining 161 individuals from six natural populations: Mt. Seorak 1, Mt. Seorak 2, Mt. Jeombong, Mt. Bangtae, Mt. Gyebang, Mt. Halla. The mean genetic diversity for all the six populations was 0.25 (S.I.). The highest genetic diversity was found in Mt. Seorak (S.I.=0.3158) and the lowest was in Mt. Gyebang (S.I.=0.1047). Comparatively low level of genetic diversity was observed (Ae=1.25, P= 64.6%, S.I.=0.25), which is a typical pattern for rare tree species. AMOVA showed exceptionally large proportion of genetic variations both for among populations (34.69%) and within populations (65.31%). Excluding Mt. Gyebang, the genetic variation among and within population was 18.71% and 81.29% respectively. The UPGMA dendrogram based on genetic distance is not suitable for geographic relationship. Genetic distance of Mt. Gyebang was most distant from the other populations. Excluding Mt. Gyebang, the genetic identities among the five populations were 0.95 to 0.97, which is very high similarity level of genetic identity. This low level of genetic variations and the lack of site in nature indicates that Lonicera caerulea var. edulis demanded a serious conservation.

• Journal of Ginseng Research
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• v.36 no.3
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• pp.322-326
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• 2012

Results of karyological study of intact plants and some callus lines of Panax ginseng are presented. In the native plants of P. ginseng the nucleus with 1 nucleolus (90%) dominate, and nucleus with 2 nucleoli is rare. One nucleolar nucleus also dominate in interphase nuclei of cells of cultivated P. ginseng (from 2006), but we also found nucleus with 2 to 3 nucleoli in the same cell lines. Interphase nuclei of P. ginseng in long cultivated lines (from 1988) contain 1 to 9 nucleoli, with a predominance of nuclei containing from 3 to 4 nucleoli. It was shown that long-time cells (cultivated since 1988) had cytogenetic changes such as increase level of polyploid and aneuploid cells, increase of nucleoli number into interphase nucleus and decrease of nuclei/nucleoli ratio. These long-time cultivated cells had very low ginsenoside content.

• Animal cells and systems
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• v.10 no.1
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• pp.27-40
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• 2006

Tree of heaven (Ailanthus altissima Swingle) as an invasive alien plant, appeared usually in the disturbed locations such as road-side, incised slope, and trampling path-side. They appeared abundantly in the trampling pathside but they did not appear or were rare in the interior of forest. Density and importance value of tree of heaven were proportionate to the relative light intensity measured according to distance from the trampling path toward forest interior and closely related to the breadth of trampling path as well. They were associated with annual, other exotic species or ruderal plants well. Distributional pattern of mature trees of them in the study area and its surrounding environments implied that they were introduced intentionally. Size class distribution of them showed that they are in expansion and artificial interferences such as, installing physical training space and developing hiking course functioned as trigger factors in their invasion and expansion. The results support the facts known generally in relation to invasion and expansion of the invasive alien plants. In this viewpoint, we suggest a management plan that applies ecological restoration principles to address ecosystems infected with tree of heaven by restoring the integral feature of the degraded nature and conserving the remained nature more thoroughly.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2915-2923
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• 2022

There is an increasing interest in passive safety systems to minimize the need for operator intervention or external power sources in nuclear power plants. Because a passive system has a weak driving force, there is greater uncertainty in the performance compared with an active system. In previous studies, several methods have been suggested to evaluate passive system reliability, and many of them estimated the failure probability using thermal-hydraulic analyses and the Monte Carlo method. However, if the functional failure of a passive system is rare, it is difficult to estimate the failure probability using conventional methods owing to their high computational time. In this paper, a procedure for the application of the Chernoff bound to the evaluation of passive system reliability is proposed. A feasibility study of the procedure was conducted on a passive decay heat removal system of a micro modular reactor in its conceptual design phase, and it was demonstrated that the passive system reliability can be evaluated without performing a large number of thermal-hydraulic analyses or Monte Carlo simulations when the system has a small failure probability. Accordingly, the advantages and constraints of applying the Chernoff bound for passive system reliability evaluation are discussed in this paper.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.3
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• pp.303-313
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• 2023

Spent fuels (SFs) are stored in a storage pool after discharge from nuclear power plants. They can be transferred to for the further processes such as dry storage sites, processing plants, or disposal sites. One of important measures of SF is the burnup. Since the radioactivity of SF is strongly dependent on its burnup, the burnup of SF should be well estimated for the safe management, storage, and final disposal. Published papers about the methodology for the burnup estimation from the known activities of important radioactive sources are somewhat rare. In this study, we analyzed the dependency of the burnup on the important radiation source activities using ORIGEN-ARP, and suggested simple correlations that relate the burnup and the important source activities directly. A burnup estimation equation is suggested for PWR fuels relating burnup with total neutron source intensity (TNSI), initial enrichment, and cooling time. And three burnup estimation equations for major gamma sources, ¹³⁷Cs, ¹³⁴Cs, and ¹⁵⁴Eu are also suggested.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.789-800
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• 2023

A vascular flora survey was conducted in 2020 to identify flora and analyze changes in the numbers of vascular flora species over the past 10 years at Gongju-weir (GW) and Baekje-weir (BW) in the Geumgang River, Republic of Korea. A total of 241 taxa were found in GW and 279 taxa in BW, and 208 taxa (88% of total taxa) were common species. The distribution of invasive species in GW and BW were seven and eight taxa, respectively. Rare plants were not identified in any of the weirs. The Poaceae family dominated in terms of number of species, followed by Asteraceae, Legumes, Cyperaceae, and Polygonaceae. Additionally, Therophytes accounted for a high proportion of Raunkiaer life forms. The numbers of vascular plant species, total taxa, naturalized plants, and invasive species have been increasing over the last 10 years. However, long-term alterations in invasive species before and after the opening of the weirs increased much more significantly in the partially opened BW than in the fully opened GW. These results indicate that the degree of barrier opening does not affect the invasion and establishment of non-native species.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.165-171
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• 1997

The floristic characteristics and ecological conservation measures for the plant resources of the Mt. Kumjung(801m), Pusan, Korea were discussed. The field works was done for about twenty times in nine major areas from March, 1995 to Octover, 1996. The total number of vascular plants In this area were summarized as 103 families, 312 genera, 493 species and 564 kinds. The fourteen kinds of artificially planted, ten kinds of Korean endemics and twenty-nine kinds of Korean rare and endangered species in the area were revised and compiled in the list. The flora of the area were categorized into the South-coast put of the Korean Region, where the species such as Platycarya strobilacea, Quercug serrata, Eutya japonica, Camellia japonica, Trachelosperm urn asia talcum vu . in termedium, Quercus acu tissima were roles as major floristic components in the Korean Region and endemized in the south-cosat part of Korea. The natural communities such as Pinus thunbergii Community, Quercus mongolica community, Cupinus laxiflora Community, Wistria floribunda Community and swamp vegetation in Bukmun area as well as upland grassland at the summit of Kodangpong were represented for their floristic values in the area. The thirty kinds of medichinal plant, fifteen kinds of ornamental plants and thirteen kinds of edible plants are faced potentially in endangered from the outrageous collections by the local peoples. The action plan for the conservation management of the area which enables sustainable use by the local peoples must have established in the near feature.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.16-16
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• 2018

Flora investigations have been conducted by many researchers for a long time in Korea. Even though large amount of investigation data has been accumulated, there is no accurate statistics or database because most of data were published in a printed form. We developed a web-based database of flora investigation, named as the Integrated Korean Flora Database (http://www.floradb.net/) to understand distribution patterns and habitats of plants in Korea. Till now, 480 published paper, 356 thesis, 76 reports and books, and 8 unpublished papers written in between 1962 and 2017 were collected and their species lists from 280 papers were parsed into the database. From 124,105 records, 3,100 species belonging to 206 families and 965 genera were identified via comparing with two major Korean plant species lists. 55 endangered species, 159 endemic species, and 367 rare species were identified. The most frequently surveyed species were Commelina communis in herbaceous and Rosa multiflora in woody plants. Microclimate data provided by Korea Meteorological Administration were also integrated and analyzed to assign cold hardness zones for each species. By comparing minimum temperature (<2%) acquired from automated weather stations (AWS) near by plant species, 6a to 10b zones (7b is the most frequent zone) were identified. Integrated Korean Flora Database will be a fundamental platform of korea flora investigation as well as a new standard for classifying distribution of plants based on accurate microclimate data. Moreover, it can also provide evidences of investigated plant species, such as specimen and/or pictures with connecting to the InfoBoss Cyber Herbarium (http://herbarium.infoboss. co.kr/) and Biodiversity Observation Datbase (BODB; http://www.biodiversitydb.org/).

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.360-385
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• 2024

This study was carried out to clarify the distribution of vascular plants in Biryongsan Mt. (1,129 m) and Baebawhisan Mt. (967 m) (a.s.l., 36° 55'~37° 06' N, 129° 03'~29° 09' E), Gyeongsangbuk-do. The surveys were conducted 13 times from April 2019 to August 2022. The vascular plants of Biryongsan Mt. and Baebawhisan Mt. was consisted a total of 570 taxa based on the voucher specimens; 108 families, 334 genera, 506 species, 17 subspecies, 44 varieties, 3 forms. Among them, the Korean endemic plants were 12 taxa. The of number of threatened and near threatened plants, as National Red List of Vascular Plants in Korea designated by the Korean National Arboretum, were 8 taxa, comprising 1 endangered (EN), 3 vulnerable (VU), and 4 near threatened (LC) species. The number of floristic target plants designated by the Ministry of Environment was 104 taxa, including 10 of level IV and 28 of level III. The naturalized plants in this area were 42 taxa. Among 570 taxa, there were 403 edible plants, 461 medicinal plants, 221 industrial plants, 306 ornamental plants, and 17 taxa with unknown usefulness respectively.