• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.355-378
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• 2019

We investigated the flora of vascular plants in Mt. Papyeong which is located in the northern part of Paju and the border of western DMZ through 13 surveys from April 2016 to August 2019. The vascular plants of Mt. Papyeong include 410 taxa; 361 species, 9 subspecies, 36 varieties, and 4 forms from 257 genera of 91 families. Among 410 taxa, we characterize endemic species, rare and endangered plants, floristic regional indicator plants, and climate change adapted plants in Korea. Specifically, there are 9 Korean endemic plants designated by Korea National Arboretum and 6 taxa by Korean Ministry of Environment. According to IUCN evaluation, there are 13 rare and endangered plants in Mt. Papyeong. On the other hand, 2 taxa were listed in a red list suggested by Korean Ministry of Environment. The floristic regional indicator plants include 46 taxa which are composed of 2 species of IV degree, 13 taxa of III degree, 11 taxa of II degree, and 20 taxa of I degree. Also, 27 naturalized plants were identified, and the percentage of Naturalized Index (NI) and Urbanization Index (UI) were 6.58%, and 8.43%, respectively. We hope that this investigation provide a valuable data for applying the further studies on the biodiversity and strategy of conservation of environment in the DMZ and Paju areas.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.396-418
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• 2018

This study was carried out to investigate the flora and the vegetation of Samusan mountain on Jecheon-si, located in the middle part of the Korean peninsula. The vascular plants which were collected in 9 times from June 2014 to October 2015 were identified as 502 taxa in total, including 102 families, 314 genera, 445 species, 6 subspecies, 49 varieties, 1 form and 1 hybrid. The largest families were as follows; Asteraceae (70 taxa), Poaceae (52 taxa), Rosaceae (30 taxa), Fabaceae (28 taxa), and Cyperaceae (20 taxa). Of them, Korean endemic plants numbered 10 taxa, and vascular plants listed in the red data according to the International Union for Conservation of Nature (IUCN) numbered 14 taxa. The floristic regional indicator plants found in this area were 61 taxa in total. Among them, 5 taxa revealed the floristic grade V, 11 for floristic grade IV, 14 for floristic grade III, 10 for floristic grade II, and 21 for floristic grade I. The alien plants were identified as 43 taxa and the percentage of naturalized index (NI) was 8.6%, and urbanization index (UI) was 13.4%, respectively. Samples of the forest vegetation on the Samusan Mt. were mainly classified as Pinus densiflora, Quercus variabilis, Q. acutissima, Q. mongolica, Zelkova serrata and Robinia pseudoacacia forest. The vertical structures of the forest were stable and the DBH-Class analyses showed that the dominant tree species would be maintained. In the surveyed areas, high plant diversity was shown, and a number of endemic, rare, calcicole plants and phytogeographically important plants were found. Nonetheless, numerous and diverse biological resources native have been consistently disturbed or damaged by human activities without some form of protection. Therefore, it is needed to set up strategies for conservation forest vegetation in this study area.

• Journal of Mushroom
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• v.19 no.3
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• pp.234-245
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• 2021

To extend the shelf life of king oyster mushrooms for export, we investigated the impacts of mushroom quality grade, fruiting body trimming, and packaging method (tray container sealed packaging vs string-tied OPP bag packaging). Quality is divided into two grades: 1^st grade, which is mushrooms adapted by lowering the cultivation temperature to 9~11℃, and 2^nd grade, mushrooms held at 13~15℃ prior to harvest. Using selected 1^st and 2^nd grade mushrooms, 3 treatments were carried out to assess effects of trimming and packaging method. Test groups included 1) trimming plus string-tied OPP bag packaging (Cut & OPP), 2) no trimming plus string-tied OPP bag packaging (Uncut & OPP), and 3) trimming plus tray container sealing packaging (Cut & Tray). Gas composition inside the packaging, changes in quality factors, and sensory evaluation for fresh quality were performed over 42 days of 0℃ storage. Overall freshness was best maintained in the following order: Cut & Tray > Cut & OPP > Uncut & OPP for both 1^st and 2^nd grade mushrooms. The shelf-life of 1st grade mushrooms was about 30 days for Cut & Tray, 28 days for Cut & OPP, and 21 days for Uncut & OPP. The shelf-life of 2^nd grade mushrooms was about 22 days for Cut & Tray, 17 ays for Cut & OPP, and 14 days for Uncut & OPP. Factors affecting fresh mushroom quality included browning of cap and stalk, and mushroom decay index. Browning of the lower part of the stalk, with related color change as noted in a^* and b^* values were the main factors indicating quality deterioration of king oyster mushrooms.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1829-1836
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• 2021

Cloud detection means determining the presence or absence of clouds in a pixel in a satellite image, and acts as an important factor affecting the utility and accuracy of the satellite image. In this study, among the satellites of various advanced organizations that provide cloud detection data, we intend to perform quantitative and qualitative comparative analysis on the difference between the cloud detection data of GK-2A/AMI, Terra/MODIS, and Suomi-NPP/VIIRS. As a result of quantitative comparison, the Proportion Correct (PC) index values in January were 74.16% for GK-2A & MODIS, 75.39% for GK-2A & VIIRS, and 87.35% for GK-2A & MODIS in April, and GK-2A & VIIRS showed that 87.71% of clouds were detected in April compared to January without much difference by satellite. As for the qualitative comparison results, when compared with RGB images, it was confirmed that the results corresponding to April rather than January detected clouds better than the previous quantitative results. However, if thin clouds or snow cover exist, each satellite were some differences in the cloud detection results.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.77-94
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• 2021

The purpose of this study was to investigate the three-dimensional characteristics of mesiodens using Cone-beam Computed Tomography(CBCT) and analyze the factors affecting complications and anesthetic methods of extraction. This study evaluated 602 mesiodens of 452 patients who underwent extraction of mesiodens at the department of Pediatric Dentistry in Seoul National University Dental Hospital between 2017 and 2019. The ratio of mesiodens patients over total patient per year was gradually increased over the past 20 years. Mesiodens with labio-palatally horizontal direction while root directing labial were the most common among the mesiodens with horizontal direction. Mesiodens were the most common at the cervical side of the adjacent teeth(37.0%) and mesiodens located in the near-palatal side were observed about 3.83 times higher than the far-palatal side. Most of the mesiodens(82.1%) were in contact with adjacent permanent teeth on all three sides of the CBCT and 46.2% of mesiodens had curved roots. The patient's age, vertical position, presence of complications, and proximity showed a significant difference in the selection of general anesthesia among anesthetic methods. The direction and vertical position of mesiodens had a significant effect on complications. These results provide a better understanding of mesiodens for establishing an accurate diagnosis and treatment plan.

• The Korean Journal of Archival Studies
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• no.21
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• pp.247-281
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• 2009

Local governments in Korea, sixteen in total, shall establish local government archives to and manage preserve their permanent archives to comply with the Public Records Management Act amended in October 2006. National Archives of Korea(NAK) directed the local governments to recruit legally qualified archivists by the end 0f 2006 and to plan on the establishment and operation of the local government archives by the end 2007. However, none of the government archives was established by far. Government officials in NAK and the local governments raised the limits of the budget and human resources. What is more serious is that they don't concern why the archives are necessary and what missions and functions the archives should have. In this paper, I summarized the present situation and problems in establishing the local archives, and what we will do to establish normal government archives. First, local governments should establish "local government records commissions" and employ qualified archivists. The local government records commission should comprise concerned and qualified members. The records commission, as a policy and decision-making body, should make plans and implement the plans to establish the local archives, establish professional training programs to produce qualified archivists, promote local archives community activities, determine operational issues, and make a long-term development plan satisfying local demands. Second, the local government archives share existing repositories of NAK. Third, after the establishment of the archives, the local archives should perform normal records and archives management of the local governments as records acts mandate, do general records surveys and appraise the records created in the local governments. The local government archives should collect valuable local archives including private archives, and arrange and make usable them to provide access. They also promote and coordinate various cultural heritage community activities related to the local archives.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.268-276
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• 2018

BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.339-348
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• 2019

The purpose of this study was to investigate the effect of carotid artery ultrasound Respectively. The carotid intima-media thickness is known to have a significant correlation with cardiovascular disease and cerebrovascular disease. We investigated the relationship between carotid intima - media thickness, body mass index, waist circumference, the blood lipid value, fasting blood glucose, glycated hemoglobin, and blood pressure using carotid artery ultrasound. The carotid artery ultrasound was considered to be abnormality of IMT thickness over 0.8 mm and the presence or absence of atherosclerotic plaque was evaluated. Serological tests were used to compare the geologic value, fasting blood glucose level, and glycated hemoglobin. As a result, waist circumference (=.022), low density cholesterol (=.004), fasting blood glucose level (.019), and glycemic index (.002) were analyzed as predictors of atherosclerosis. In the ROC curve analysis, sensitivity was 87.80% (95% CI: 73.8-95.9), specificity was 41.67% (95% CI: 30.2-53.9), sensitivity was 78.05% (95% CI: 62.4-89.4) in low density lipoprotein, Specificity was 50.00% (95% CI: 38.0-62.0), sensitivity was 73.11% (95% CI: 57.1-85.8), specificity was 61.11 (95% CI: 48.9-72.4) and sensitivity was 82.93%-91.8) and a specificity of 43.06% (31.4-55.3). In logistic regression analysis, the risk of atherosclerosis was 0.248 times at waist circumference (WC)> 76 cm, 3.475 times at low-density lipoprotein (LDL-C) ${\geq}124mg/dL$, 0.618 at HbA1c> 5.4% It appeared as a times. We suggest that prospective study of carotid artery ultrasound should be performed for the effective prevention of cardiovascular diseases.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.54-63
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• 2019

As a part of the national marine ecosystem monitoring program, the temporal and spatial variation of sedimentary environment and pollution of organic matters and trace metals from four major tidal flats, i.e., Ganghwa Is., Garolim bay, Jeung Is., Suncheon bay, was investigated for 3 yerars from 2015 to 2017. The mean grain size of the sediment was $5.0-5.3{\varnothing}$ at Ganghwa Is, $4.5-4.8{\varnothing}$ at Garolim bay, $6.1-6.5{\varnothing}$ at Jeung Is, and $8.6-8.7{\varnothing}$ at Suncheon bay. The mean grain size (Mz) tended to decrease from the north (Ganghwa Is.) to the south (Suncheon bay). The ignition loss (IL) was 15.5% in Suncheon bay in 2015, which was relatively high compared to other sites, but gradually decreased over time from 8.3% in 2016 to 7.0% in 2017. In Jeung Is. and Suncheon bay, the concentration of Zn and As exceeded the threshold effect level (TEL) at some stations, but the range of trace metals in the other sites was below the level. In Jeung Is., the Mz and concentration of trace metals except Hg was positively correlated (r= 0.40-0.88, P<0.05). On the other hand, Mz was negatively correlated with trace metals (P<0.05) in Suncheon bay. The geoaccumulation index ($I_{geo}$) to evaluate contamination status of sediments for trace metal was less than 1(not contaminated) for Cu, Zn, Pb, Cd and Hg, and 2-3 (moderately to strongly polluted) for As at several stations in Suncheon bay and Jeung Is.

• Korean Journal of Remote Sensing
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• v.35 no.2
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• pp.251-263
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• 2019

Sentinel-2 Multi Spectral Instrument(MSI) launched by the European Space Agency (ESA) offered high spatial resolution optical products, enhanced temporal revisit of five days, and 13 spectral bands in the visible, near infrared and shortwave infrared wavelengths similar to Landsat mission. Landsat satellite imagery has been applied to various previous studies, but Sentinel-2 optical satellite imagery has not been widely used. Currently, for global coverage, Sentinel-2 products are systematically processed and distributed to Level-1C (L1C) products which contain the Top-of-Atmosphere (TOA) reflectance. Furthermore, ESA plans a systematic global production of Level-2A(L2A) product including the atmospheric corrected Bottom-of-Atmosphere (BOA) reflectance considered the aerosol optical thickness and the water vapor content. Therefore, the Sentinel-2 L2A products are expected to enhance the reliability of image quality for overall coverage in the Sentinel-2 mission with enhanced spatial,spectral, and temporal resolution. The purpose of this work is a quantitative comparison Sentinel-2 L2A products and fully simulated image to evaluate the applicability of the Sentinel-2 dataset in cultivated land growing various kinds of crops in Korea. Reference image of Sentinel-2 L2A data was simulated by airborne hyperspectral data acquired from AISA Fenix sensor. The simulation imagery was compared with the reflectance of L1C TOA and that of L2A BOA data. The result of quantitative comparison shows that, for the atmospherically corrected L2A reflectance, the decrease in RMSE and the increase in correlation coefficient were found at the visible band and vegetation indices to be significant.