• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.35-63
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• 2015

A floristic, field research was conducted from March 2005 to October 2012 the Woraksan National Park (N $36^{\circ}46^{\prime}{\sim}36^{\circ}59^{\prime}$, E $128^{\circ}02^{\prime}{\sim}128^{\circ}19^{\prime}$) to characterize the flora of the region. Especially, we divided the surveyed region into nine representative collection areas based on floristic components were compared and analyzed. This field study discovered significant plants in various categories. The 41 surveys revealed that the vascular plants in this region comprised 815 taxa: 116 families, 429 genera, 717 species, 4 subspecies, 78 varieties and 16 forms. In this study, 80 taxa were firstly recorded from this region. Korean endemic plants numbered 22 taxa, and the fifteen taxa rare plants designated by Korean Forest Service as were found in this region. The taxa in the category II of rare and endangered plants and the taxa with the higher rank than the third degree among the floristic regional indicator plants designated by Korean Ministry of Environment were one and 56, respectively. From a geographical perspective, limited distributions of Matteuccia struthiopteris, Spiraea trichocarpa, and Aster tataricus at a latitudes higher than that of Woraksan National Park. Moreover, this study has confirmed that the Woraksan National Park is the species diversity center for Asarum koreanum, Elsholtzia angustifolia, and Allium linearifolium in the central province of the Korean peninsula. Inaddition, the naturalized plants of 54 taxa were recorded.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.415-430
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• 1996

The purpose of this study was to evaluate the stress distributions in the surrounding tissues of the teeth seated by indirect retainers in three different teeth of unilateral distal extension partial denture when the dislodging forces were applied on denture bases. Three dimensional photoelastic models were made. The teeth on which indirect retainers were seated were mandibular left lateral incisor (Model I), canine (Model II), and first premolar (Model III). The dislodging force with 860mg at $45^{\circ}$ angulation to occlusal plane was applied to each model. Three dimensional photoelastic stress analysis was done, and the records were diagramed and analysed. The results were as follows : The compressive stresses were shown the most on neck portions of buccal, mesial, and distal sides in all three models. Slight tensile stresses were shown on neck portions of lingual sides in all three models. The compressive stresses on buccal side were shown in strength in such order as model I, model II, and model III. The compressive stresses were shown on neck portion of mesial and distal sides of model I and mode II, with model I more than Model II. The compressive stresses were shown only on neck portion of mesial side on Model III. The general overall magnitude of compressive stresses were shown in strength in such order as Model I, Model II, and Model III.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.20-30
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• 2009

To study reproductive dynamics of a Gold-spotted pond frog (Rana chosenica) population located at Gangnae, Cheongwon, Chungbuk, Korea, we monitored the population over 207 days between April 17$^{th}$ 2007 and December 18$^{th}$ 2008 using a drift fence accompanied with 20 pitfall traps. The population was located in an agricultural wetland, compromising three small ponds. Gold-spotted pond frogs immigrated into the wetland between April 16$^{th}$ and June 17$^{th}$ and emigrated from the wetland between September 21$^{st}$ and November 12$^{th}$. Precipitation showed a positive correlation with the number of migrated frogs in Autumn 2007 and Spring 2008, but other environmental factors such as air and water temperatures and relative humidity did not show any significant relationships. In general, small frogs first migrated into and from the wetland, but the trend was not strong. Female gold-spotted pond frogs were bigger than males. During the autumn migration, small frogs of which snout-vent length was smaller than 20 mm were found, indicating that successful breeding occurred in the population. Our results could be useful to conserve this endangered species in Korea.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.345-353
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• 2018

Hibernation is regarded as a physiological and behavioral adaptation that permits the survival of animals such as bats during seasonal periods of energy shortage. This study investigated the hibernation period of Plecotus ognevi in the temperate climate zone and the relationship between the thermal preference and hibernating process of bats. We hypothesized that the hibernation period of bats is closely related to the external temperature and temperature preference of bat species in the temperate region. To verify this hypothesis, we surveyed the distribution of the P. ognevi population in South Korea, and the temperature preference and the characteristics of hibernacula of P. ognevi. We predict that hibernation in the bat will begin when the external temperature drops below the thermal preference of the species and will leave from hibernation when the external temperature is higher than the thermal preference. P. ognevi hibernated in roosts maintained in low temperature ambient conditions with $-3.5{\sim}7.5^{\circ}C$). The body temperatures (averaged $3.01{\pm}1.30^{\circ}C$, ranged $0.1{\sim}7.8^{\circ}C$) of hibernating bats were closely related to the rock surface temperatures rather than the ambient temperatures. The bats began to hibernate in late November and final arousals occurred in mid-March, so that the total length of the hibernation was 115~120 days. The period of hibernation was strongly influenced by fluctuations in the external mean temperature. This study suggests that the onset and termination of P. ognevi hibernation is due to the interaction between the temperature of the hibernacula and that of the external environment and is based on the thermal preference of the bats. The study also suggests that the hibernation strategy such as thermal preference and hibernation periods of this species affect to distribution as bat species adapting to a severely climate.

• Korean Journal of Environment and Ecology
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• v.35 no.5
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• pp.490-502
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• 2021

This study was conducted to analyze the current status of fish fauna and characteristics of the fish community according to the habitat of Woraksan National Park, Korea. The spatially balanced sampling selected 20 stations from major streams of Woraksan National Park, and three surveys were conducted in each season. The physical environments of the habitat were mostly mountain streams (Aa), with large stones and gravels scattered over the stream. The average altitude of the habitat was 304.4 m, and the average depth of water was 40.3 cm, being less than 1 m in most cases, and the river water level was distributed from 3rd to 5th streams. The principal component analysis of the physical environmental factors by habitat showed that the substrate properties differed according to the altitude. The survey identified a total of 2,183 individuals in 16 species belonging to 7 families. The dominant species was Zacco koreanus(86.2%), and the subdominant species was Rhynchocypris oxycephalus(3.8%). Pseudopungtungia tenuicorpa, classified as the endangered wildlife II, was the first endangered legally protected species found in this survey. Analysis of the rank abundance curve model in the fish community showed the Zipf model at 9 out of 20 points, the Lognormal model in 3 points, and the Preemption model in 4 points. The remaining 4 habitats showed only one species and were not analyzed. The canonical correspondence analysis of 20 stations and fish species was performed to understand the characteristics of the fish community according to environmental factors. The fish communities were divided according to differences in habitat environment by the altitude.

• Korean Journal of Plant Resources
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• v.35 no.5
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• pp.614-640
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• 2022

We investigated vascular plants of Bigeumdo and Dochodo Island in Shinan-gun, Jeollanam-do, Korea. By referring to 4 field surveys between June and September in 2021, a total of 490 taxa were identified and grouped into 113 families, 332 genera, 452 species, 6 subspecies, 27 varieties, and 3 forms. Among those observed, 232 taxa comprising 84 families, 189 genera, 220 species, 4 subspecies, 8 varieties, 4 forms were observed in Bigeumdo, 428 taxa comprising 107 families, 305 genera, 397 species, 5 subspecies, 23 varieties and 3 forms were observed in Dochodo. Among them, 7 taxa were Korean endemic plants. Protected species designated by the Ministry of Environment were 2 taxa of level II. In terms of threated plants according to the IUCN Red List Categoty, there were 5 taxa, consisting of 1 endangered species (EN), 3 vulnerable species (VU), 1 Near Threatened (NT). In total, there are 36 taxa of floristic regional indicator plants, including 1 level V taxa, 5 level IV taxa, 28 level III taxa. In Korea, 3 taxa were the northern distributional limit to Bigeumdo and Dochodo. Alien plants were 58 taxa.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.3
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• pp.158-172
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• 2022

The distribution of seabirds was investigated in 24-34 major coastal wetlands in Korea from 2015 to 2019. During the study period, seven orders, 16 families, and 111 species were observed, and the largest number of species (51-89 species) was recorded in 2018. 92,821-265,783 individuals per year were observed with the largest number in 2018. The largest number of species (55-72 species) was observed in the southern sites of Jeollado, and the largest number of individuals (annual average of 62,542 individuals) was found in Chungcheong regions. The largest number of seabird species (68 species) was observed at the Suncheon Bay site in 2016, and the largest number of individuals (95,399 individuals) was observed at Biin and Jangan sites in 2018. In terms of the habitat type of seabirds, at the family level, shorebirds appeared most frequently with an average of 38%, followed by waterfowl, wading birds, seabirds, and raptors. With regard to legally protected species, eight protected marine species, 19 endangered wildlife species (Level I: six species, Level II: 13 species), and twelve natural monument species were observed. Overall, there was a significant difference in the number of species and individuals of seabirds in the Korean coastal wetlands during the research period. This suggests the importance of conducting systematic and continuous seabird surveys and developing a conservation policy considering habitat characteristics.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.73-84
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• 2023

The objective of this study was to evaluate biodiversity and natural habitat environment of freshwater ecosystem. Our aim was therefore to produce a set of biodiversity and habitat indicators based on multi-parameters of water quality and biodiversity by analyzing the characteristics of the results by indicators. We selected four indicators a) anthropogenic disturbance, b) habitat diversity, c) biodiversity, d) ecosystem structure. The fishes cohabiting with Brachymystax lenok tsinlingensis were Rhynchocypris kumgangensis and Zacco koreanus. As a result of the anthropogenic disturbance evaluation, it was analyzed that vegetation embankment showed a more stable environment in the tributary than the main stream, and other disturbance was not confirmed As a result of the habitat diversity evaluation, it was analyzed that habitat evaluation index showed a high score of 200 more on average, showing an optimal habitat condition. As a result of the biodiversity evaluation, it was analyzed as a clean habitat condition with a high proportion of sensitive species, abundant dissolved oxygen, and little pollutants. As a results of the ecosystem structure, the ecological health condition metrics and appearance of endangered species showed large score deviation, but it was analyzed that the stream ecosystem health was generally excellent. There was a slight correlation between the habitat environment and the results of the nature habitat evaluation according to the appearance of the B. lenok tsinlingensis.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.83-93
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• 2023

This study was conducted to clarify the environmental variables that affect the appearance of Mauremys reevesii and to understand the relationship between M. reevesii and the variables. Habitat environmental survey was implemented by selecting 17 environmental variables considering ecological characteristics of M. reevesii in the main reservoir in Gurye-gun, the Republic of Korea. And the habitat data on the presence and absence of M.reevesii were analyzed statistically. The habitat suitability model of M. reevesii was described in following equation : logit (p) = -3.68 + (0.17 × leaf litter depth) + (1.55 × vegetation coverage of overstory on land) + (0.71 × coverage of midstory on land) + (0.96 × vegetation coverage of understory on water). This information gained is valuable for better understanding the distribution and how to conserve and promote populations of M. reevesii occurring in the Republic of Korea.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.469-489
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• 2023

Six field surveys were conducted at 29 locations from April 2020 to April 2022 to identify the freshwater flora of the Taean Peninsula. Based on the collected specimens, the vascular plants of the Taean Peninsula were summarized as 391 taxa: 94 families, 248 genera, 362 species, 5 subspecies, and 24 varieties. Freshwater plants in the Taean Peninsula consisted of 104 taxa, 45 taxa for aquatic plants, and 59 taxa for wetland plants. When classified by life history, annuals accounted for 33 taxa, winter annuals 5 taxa, biennial 6 taxa, and perennials accounted for most of the 60 taxa. Among the 391 identified taxa, 2 taxa of Endangered plants, 3 taxa of Korean endemic plants, 5 taxa of IUCN red list plants, 49 taxa of Korean floristic target plants, 38 taxa of biological resources subject to the approval of outbound transfer, 55 taxa alien plants and 7 taxa of ecosystem disturbing plant. The results of this study are intended to be used as basic data on the freshwater environment and distribution of aquatic plants in the Taean Peninsula.