• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1146-1156
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• 2021

Single-unit probabilistic safety assessment (SUPSA) has complex Boolean logic equations for accident sequences. Multi-unit probabilistic safety assessment (MUPSA) model is developed by revising and combining SUPSA models in order to reflect plant state combinations (PSCs). These PSCs represent combinations of core damage and non-core damage states of nuclear power plants (NPPs). Since all these Boolean logic equations have complemented gates (not gates), it is not easy to generate exact Boolean solutions. Delete-term approximation method (DTAM) has been widely applied for generating approximate minimal cut sets (MCSs) from the complex Boolean logic equations with complemented gates. By applying DTAM, approximate conditional core damage probability (CCDP) has been calculated in SUPSA and MUPSA. It was found that CCDP calculated by DTAM was overestimated when complemented gates have non-rare events. Especially, the CCDP overestimation drastically increases if seismic SUPSA or MUPSA has complemented gates with many non-rare events. The objective of this study is to suggest a new quantification method named probability subtraction method (PSM) that replaces DTAM. The PSM calculates accurate CCDP even when SUPSA or MUPSA has complemented gates with many non-rare events. In this paper, the PSM is explained, and the accuracy of the PSM is validated by its applications to a few MUPSAs.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.226-229
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• 2008

We described and illustrated a rare species in Korea, Hypoxis aurea Lour. (Hypoxidaceae) which was rediscovered about 70 years after its first collection from Jeju island in Korea. The members of the family Hypoxidaceae R. Br. are distinguished from the plants of Amaryllidaceae J. St-Hill. by having grass-like leaves, an invisible stem which is modified into a corm or a rhizome, trimerous, and radially symmetric flowers with an inferior ovary developing into a capsule on scapes. Hypoxis aurea Lour. is readily distinguishable from Curculigo orchinoides Gsertn. in Japan by beakless ovary and capsular fruit. The number of somatic chromosome is 2n=54.

• Korean Journal of Plant Resources
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• v.30 no.5
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• pp.489-506
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• 2017

This study was carried out to investigate the flora of Geumseongsan Mt. (Geumsan-gun Chungnam). The vascular plants were collected 30 different times, from July 2015 to June of 2016. The results showed that there were 483 taxa in total, included 112 families, 358 genera, 417 species, 8 subspecies, 48 varieties, 8 forms and 2 hybrids. Of these vascular plants, red-list species managed by the Ministry of Environment of Korea included 3 species, and 8 species Korea Forest Service. The endemic species to Korea were identified to 4 species. There were 29 taxa specially designated floristic regional indicator plants by the Ministry of Environment of Korea. The alien plants were identified as 42 taxa, and their naturalization ratio was 8.6%. Usage of 483 taxa were consisted of 190 taxa (39.3%) of edible plants, 162 taxa (33.5%) of pasture plants, 154 taxa (31.8%) of medicinal plants, 58 taxa (12.0%) of ornamental plants, 14 taxa (2.8%) of timber plants, 5 taxa (1.0%) of fiber plants, and 2 taxa (0.4%) of industrial plants.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.78-95
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• 2009

This study was examined the vascular plants and their characteristics cited in 311 science textbooks of elementary and secondary schools used in the fifth to seventh curriculum. Vascular plants were composed of 129 families, 332 genera, 383 species, 2 subspecies, 47 varieties, 6 forma, and 3 hybrid, totaling 441 taxa. The herbs and trees were consists of 280 taxa (63.5%) and 161 taxa (36.5%), respectively. Native species (241 taxa) were more cited than non-native species (200 taxa). The number of species within a family were high ranked in 35 taxa of Compositae, and 26 taxa of Gramineae. Nine species including endemic genus Hanabusaya Nakai and Abeliophyllum Nakai among the 441 taxa were Korean endemic, and the 25 rare and 12 endangered plants were also included. Based on the list of the species of specially designated plants by the Ministry of Environment, 83 taxa were recorded in the investigated textbooks, and the naturalized plants were 16 taxa. 441 taxa listed consists of 185 taxa (41.9%) of edible plants, 148 taxa (33.5%) of medicinal plants, 139 taxa (31.5%) of ornamental plants, 87 taxa (19.7%) of pasture plants, 34 taxa (7.7%) of timber plants, 13 taxa (2.9%) of miscellaneous plants, 8 taxa (1.8%) of fiber plants, and 3 taxa (0.7%) of industrial plants.

• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.383-397
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• 2011

This study was carried out to investigate the flora of the southeastern areas, including Donghae-si and Samcheok-si, of Gangwon-do. Vascular plants based on voucher specimens were summarized as 750 taxa, including 109 families, 394 genera, 642 species, 5 subspecies, 90 varieties, and 13 forms. Among the investigated 750 taxa, 17 Korean endemic, 38 rare plants and 147 specially designated plants by the Ministry of the Environment were also included. The naturalized plants were 28 taxa, and the percent of naturalized plant species was estimated as 3.7%. The life form of the investigated taxa was the H-R5-D4-e type. The usefulness of the plants of the 750 taxa listed consists of 284 taxa (37.9%) of edible plants, 232 taxa (30.9%) of medicinal plants, 124 taxa (16.5%) of pasture plants, 88 taxa (11.7%) of ornamental plants, 21 taxa (2.8%) of timber plants, 20 taxa (2.7%) of fiber plants, 7 taxa (0.9%) of miscellaneous plants and 3 taxa (0.4%) of industrial plants.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.248-270
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• 2013

The purpose of this study is to collect the raw data for conservation of plant ecosystem by surveying and analysing the flora of Mt. Geumgok located in Gyeongju-si, Gyeongsangbuk-do, Korea. The flora were summarized as 453 taxa including 91 families, 298 genera, 397 species, 4 subspecies, 46 varieties and 6 forms. The rare plants designated by Korea Forest Service were 3 taxa such as Eranthis byunsanensis B.Y.Sun, Potentilla discolor Bunge and Iris odaesanensis Y.N.Lee. The Korean endemic plants were 6 taxa such as Carpinus laxiflora (Siebold & Zucc.) Blume, Eranthis byunsanensis B.Y.Sun, Philadelphus schrenkii Rupr., Lespedeza maritima Nakai, Vicia chosenensis Ohwi and Weigela subsessilis (Nakai) L.H.Bailey. The specific plants by floristic region were 36 taxa such as Pinus koraiensis Siebold & Zucc., Salix chaenomeloides Kimura, Anemone raddeana Regel, Chloranthus japonicus Siebold, Euphorbia pekinensis Rupr., Ilex macropoda Miq., Ajuga multiflora Bunge, Saussurea odontolepis Sch.Bip. ex Herd, Viola orientalis (Maxim.) W.Becker, Betula davurica Pall., Vitex negundo var. incisa (Lam.) C.B.Clarke and Cimicifuga heracleifolia Kom.. The naturalized plants were 36 taxa such as Fallopia dumetorum (L.) Holub, Lepidium apetalum Willd., Robinia pseudoacacia L., Trifolium repens L., Euphorbia supina Raf., Ipomoea purpurea Roth, Veronica persica Poir., Bidens pilosa L., Carduus crispus L., Xanthium canadense Mill., Bromus unioloides H.B.K. and Festuca arundinacea Schreb.. The invasive alien plants were 2 taxa such as Ambrosia artemisiifolia L. and Aster pilosus Willd.. The ratios of the urbanized index(UI), the naturalized index(NI) and the disturbed index(DI) were 11.2%, 7.9% and 18.2% each.

• Korean Journal of Plant Taxonomy
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• v.37 no.1
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• pp.41-59
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• 2007

This study was to establish the floristic composition of northern region in Gyeonggi-Province area($126^{\circ}45^{\prime}-127^{\circ}37^{\prime}E$, $37^{\circ}31^{\prime}-38^{\circ}17^{\prime}N$). This work was investigated from April, 1988 to October, 2004. The flora of vascular plants of northern region in Gyeonggi-Province were consisted of total 2,030 taxa; 145 families, 656 genera, 1,611 species, 7 subspecies, 320 varieties, 1 subvarieties and 91 formae. Among them, Korean endemic species were composed of 46 families, 85 genera, 84 species, 35 varieties, 1 subvarieties, and 18 formae, total 138 taxa. The rare and endangered plants based on floral region indicated by Ministry of Environment were 416 taxa; V rank species 18 taxa, IV rank species 79 taxa, III rank species 111 taxa, II rank species 80 taxa, I rank species 128 taxa. Also the naturalized plants were 114 species, correspond to 39.7% of among total 287 species appeared in South Korea. the result of PCA, Gwangju mountain chain at northern region of Gyeonggi-Province has rich and diverse vascular plants, and there are many Korean endemic, rare and endangered plants. therefore Gwangju mountain chain must be the core axis in for conserving the plant biodiversity and richness.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.209-224
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• 2012

This study was carried out to survey the vascular plants of Namhan River located in Chungju-si, and the period of survey was from June, 2010 to June, 2011. The results are as follows. The vascular plants distributed in Neungam, Mokgye and Jangcheon around Namhan river were summarized as 225 taxa including 52 families, 164 genera, 200 species, 23 varieties and 2 forms. The rare plant designated by Korea Forest Service was $Aristolochia$ $contorta$ Bunge, and the endemic plant was identified as $Salix$ $koriyanagi$ Kimura. The specific plants by floristic region were 7 taxa including $Salix$ $chaenomeloides$ Kimura, $Aristolochia$ $contorta$ Bunge, $Actinostemma$ $lobatum$ Maxim., $Artemisia$ $selengensis$ Turcz., $Cirsium$ $pendulum$ Fisch., $Alisma$ $plantago-aquatic$ var. $orientale$ Samuels. and $Carex$ $versicaria$ L.. The naturalized plants were 47 taxa including $Fallopia$ $dumetorum$ (L.) Holub., $Chenopoidum$ $album$ L., $Silene$ $armeria$ L., $Brassica$ $juncea$ (L.) Czern., $Melilotus$ $alba$ Medicus, $Trifolium$ $pratense$ L., $Oenothera$ $erythrosepala$ Borb$\acute{a}$s, $Ipomoea$ $hederacea$ var. $integriuscula$ A.Gray, $Bidens$ $frondosa$ L., $Matricaria$ $inodora$ L., $Xanthium$ $canadense$ Mill., $Panicum$ $dichotomiflorum$ Michx. and so forth. In life forms, megaphanerophytes (M) were 13 taxa, 13 taxa in nanophanerophytes (N), 14 taxa inchamaiphytes (Ch), 40 taxa in hemicryptophytes (H), 20 taxa in geophytes (G), 103 taxa in therophytes (Th) and 22 taxa in hydrophytes (HH). The ratios of the naturalized index (NI), the urbanized index (UI) and the disturbed index (DI) were 20.9%, 14.6% and 18.2% in all sites.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.231-244
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• 2019

The purpose of this study is to offer the basic information for the rational management plan in construction and running of eco-forest by analyzing the vascular plant of the constructreserved site of eco-forest in Mt. Daeun, Yangsan-si, Gyeongsangnam-do. The vascular plants were 280 taxa; 75 families, 179 genera, 245 species, 3 subspecies, 28 varieties and 4 forma. The Korean endemic plants were 6 taxa including Pseudostellaria coreana, Stewartia pseudocamellia, Primula modesta var. hannasanensis and so forth. The rare plants were Juniperus chinensis var.sargentii, Prunus yedoensis, Primula modesta var. hannasanensis, Chionanthus retusus and Scopolia japonica. The naturalized plants were 14 taxa including Rumex acetosella, Lepidium apetalum, Trifolium repens, Oenothera biennis, Veronica persica and so forth. The invasive alien plants were Rumex acetosella and Ambrosia artemisiifolia. Specific plant species by floristic region were total 24 taxa; Prunus yedoensis and Primula modesta var. hannasanensis in class V, Juniperus chinensis var. sargentii and Acer pictum subsp. mono in class IV, 5 taxa including Dryopteris bissentiana, Scolopolia japonica and so forth in class III, Pseudostellaria coreana, Potentilla dickinsii and Chionanthus retusus in class II, 12 taxa including Acotinum jaluense, Clematis patens and so forth in class I.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.493-512
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• 2019

The purpose of this study was to provide the basic data necessary for establishing a vegetation management plan for the Yeongcheon River area by presenting a better understanding of the distribution and characteristics of naturalized plants through an investigation of the flora present in the Yeongcheon riverside, in Jinju, South Korea. Vascular plants were investigated for a total of 470 taxa, including 90 families, 282 genera, 425 species, one sub-species, 38 varieties, and six forms. Together, these accounted for 9.62% of the vascular plants (4,881 species) in Korea. Gramineae was the most abundant at 77 taxa (16.38%), followed by Cyperaceae at 56 taxa (11.91%), Leguminosae at 33 taxa (7.02%), Cyperaceae at 25 taxa (5.32%), and Rosaceae at 22 taxa (4.86%). Thirty species of indicator plants were surveyed and, among them, annual plants and hemicryptophytes accounted for a significantpercentage. Among ground plants, trees, shrubs, and sub-shrubs were surveyed to include 23 (4.89%), 17 (3.61%), and 14 taxa (2.97%), respectively. Furthermore, 36 aquatic plant taxa were found. Six rare plant taxa were surveyed including Penthorum chinense, Melothria japonica, Aristolochia contorta, Acorus calamus, Millettia japonica, and Magnolia kobus. Floristic special plants comprised 35 taxa,including 26 families, 34 genera, 34 species, and one variety. Plants endemic to Korea included six species. Naturalized plant species comprised 71 taxa, including 18 families, 53 genera, 68 species, and three varieties. The naturalization rate and urbanization index were 15.1% and 22.1%, respectively. Ecological disturbance species in Korea comprised nine taxa, including four families, eight genera, eight species, and one variety. These groups accounted for 64% of the ecological disturbance species in Korea. Ecological disturbance species in Korea tended to increase toward the downstream of Yeongcheon River. In particular, Ambrosia artemisiifolia and Sicyos angulatus, which cause human allergies and disrupt the habitats of plants and animals, must be removed artificially.