• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.341-354
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• 2021

A large part of Gapyeong is occupied by Korean pine (Pinus koraiensis) and Japanese larch (Larix kaempferi) plantations. Abies holophylla stands are scattered throughout Gapyeong, but little information on their distribution is available. This study explored the potential of succession from planted species to native A. holophylla in plantations. Trees were inventoried and regeneration of A. holoplhylla and stand management history were examined in Korean pine, Japanese larch, and A. holophylla-dominated stands. The importance percentage of A. holophylla was the highest among species with a range of 36.1% to 79.1% in all stands and the density of A. holophylla in understory (DBH <2 cm or <1.3 m height) ranged from 50 to 5,820 trees ha^-1. Non-metric multidimensional scaling classified stands into four types, AN, AP, AM, and P. The AN type showed a reverse J-shape DBH distribution, which was similar to that in natural A. holophylla stands. Both AP and AM types included Korean pine plantations with A. holophylla seed trees within stands. For AP, A. holophylla competed with planted species in overstory and deciduous broadleaved species in understory. The AM type was once thinned from below, thus stem density in the mid DBH classes was lower than upper or lower DBH classes. The P type consisted of plantations without A. holophylla seed trees. However, understory regeneration of A. holophylla was abundant through seed supply from A. holophylla in adjacent stands. Plantations with A. holophylla seed trees within or in adjacent stands showed vigorous natural regeneration of A. holophylla, highlighting the potential for succession from planted species to native A. holophylla in the Gapyeong area. Further studies can help develop techniques to restore plantations to native species-dominated natural stands using ecological succession.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.369-392
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• 2021

This study aimed to provide basic data for efficient flora management of vascular plants, halophytes, and naturalized plants in the Gwangpo Bay area in Sacheon city, Gyeongsangnam-do. The flora found in this area incorporated 520 taxa, including 93 families, 299 genera, 466 species, 3 subspecies, 41 varieties, and 10 forma, and accounted for approximately 10.6% of total vascular plants (4,884 species) in Korea. According to the survey, 76 species of Gramineae showed the highest frequency (14.6%), followed by 67 species of Compositae (12.8%), 34 species of Leguminosae (6.5%), 27 species of Cyperaceae (5.2%), and 22 species of Rosaceae (4.2%). Rare plant species designated by the Korea Forest Service were categorized into six taxa, including three taxa in the LC grade, one taxon in the CR grade, one taxon in the VU grade, and one taxon in the EN grade. Korea endemic plants belonged to nine taxa consisting of seven families, seven genera, and nine species. The special floristic plants included 44 taxa, including one taxon (Prunus yedoensis) in the V grade, four taxa in the IV grade, ten taxa in the III grade, six taxa in the II grade, and 23 taxa in the I grade. Naturalized plants included 62 taxa consisting of 15 families, 47 genera, 59 species and 3 varieties. Halophytes consisted of 27 taxa, including 13 families, 24 genera, 24 species, 2 varieties, 1 forma, which consisted of Atriplex gmelinii, Suaeda glauca, Suaeda maritima, and Lathyrus japonicus. Invasive alien species in the Gwangpo Bay area included seven taxa. Since Ambrosia artemisiifolia, Sicyos angulatus, andPaspalum distichum var. indutummay have harmful effects on native plants, these plants must be artificially controlled.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.161-176
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• 2021

In this study, one of the distributed hydrologic models, VELAS, was used to analyze the variation of hydrologic elements based on water balance analysis to evaluate the groundwater recharge in more detail than the annual time scale for the past and future. The study area is located in Yanggok-ri, Seobu-myeon, Hongseong-gun, Chungnam-do, which is very vulnerable to drought. To implement the VELAS model, spatial characteristic data such as digital elevation model (DEM), vegetation, and slope were established, and GIS data were constructed through spatial interpolation on the daily air temperature, precipitation, average wind speed, and relative humidity of the Korea Meteorological Stations. The results of the analysis showed that annual precipitation was 799.1-1750.8 mm, average 1210.7 mm, groundwater recharge of 28.8-492.9 mm, and average 196.9 mm over the past 18 years from 2001 to 2018 in the study area. Annual groundwater recharge rate compared to annual precipitation was from 3.6 to 28.2% with a very large variation and average 14.9%. By the climate change RCP 8.5 scenario, the annual precipitation from 2019 to 2100 was 572.8-1996.5 mm (average 1078.4 mm) and groundwater recharge of 26.7-432.5 mm (average precipitation 16.2%). The annual groundwater recharge rates in the future were projected from 2.8% to 45.1%, 18.2% on average. The components that make up the water balance were well correlated with precipitation, especially in the annual data rather than the daily data. However, the amount of evapotranspiration seems to be more affected by other climatic factors such as temperature. Groundwater recharge in more detailed time scale rather than annual scale is expected to provide basic data that can be used for groundwater development and management if precipitation are severely varied by time, such as droughts or floods.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.211-217
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• 2021

The purpose of this study is based on the convergence establishment of a coronavirus infection management system that can occur during clinical trials by grasping the knowledge of corona, infection possibility, infection prevention possibility, and implementation level of infection prevention behavior of radiologists working at K University Hospital. It is in providing data. This study was a descriptive research study, and data were collected from 50 radiologists working at K University Hospital from March 25 to June 30, 2020. The characteristics of the subjects and their knowledge of the COVID-19, the possibility of infection, the possibility of infection prevention, and the level of implementation of infection prevention actions were surveyed, and the collected data were analyzed with SPSS 25.0. The frequency and percentage were calculated for the general characteristics and infection-related characteristics of the subjects. The correlation between variables was analyzed by Pearson's correlation coefficient, and the factors influencing the progression of infection prevention behavior were analyzed by multiple regression analysis. Factors influencing COVID-19 infection prevention behavior shown in this study were 1.7 points for infection prevention behavior when corona knowledge increased by 1 point, and infection prevention activity increased by 11.3 points when the level of transmission pathway recognition rose 1 point. When the figure rose by 1 point, the infection prevention behavior increased by 4.2 points. When looking at the standard regression coefficient, preventive behavior is performed. Among knowledge, transmission path perception, and anxiety, the factor that has the greatest influence was the perception of the transmission path of COVID-19. As factors influencing the implementation of infection prevention actions, knowledge of COVID-19, awareness of transmission paths, and anxiety appear to be the potential of infection prevention, so in the event of a corona outbreak, information on infectious diseases and education on the possibility of infection prevention should be provided to promote the implementation of preventive action.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.6
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• pp.245-253
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• 2021

RC slab bridges account for the largest portion of deteriorated bridges in Korea. However, most RC slabs are not included in the first and second classes of bridges, which are subject to bridge safety management and maintenance. The highest damaged components in highway bridges are the subsidiary facilities including expansion joints and bearings. In particular, leakage through expansion joints causes deterioration and cracks of concrete and exposure of reinforced bars. Therefore, this study analyzed the effect of adhesion damage at expansion joints on the response of the deck in RC slab bridges. When the spacing between the expansion joints at both ends was closely adhered, cracks occurred in the concrete at both ends of the deck due to the resistance rigidity at the expansion joints. Based on the response results, the correlation analysis between displacements in the longitudinal direction of the expansion joint and concrete stress at both ends of the deck for each damage scenario was performed to investigate the effect of the occurrence of damage on the bridge behavior. When expansion joint devices at both sides were damaged, the correlation between displacement and stress showed a low correlation of 0.18 when the vehicles proceeded along all the lanes. Compared with those in the intact state, the deflections of the deck in the damaged case at both sides showed a low correlation of 0.34 to 0.53 while the vehicle passed and 0.17 to 0.43 after the vehicle passed. This means that the occurrence of cracks in the ends of concrete changed the behavior of the deck. Therefore, data-deriven damage detection could be developed to manage the damage to expansion joints that cause damage and deterioration of the deck.

• Journal of Life Science
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• v.29 no.4
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• pp.410-420
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• 2019

Citrus unshiu peel extracts possess a variety of beneficial effects, and studies on their anticancer activity have been reported. However, the exact mechanisms underlying this activity remain unclear. In the current study, the apoptotic effect of ethanol extract of C. unshiu peel (EECU) on human breast adenocarcinoma MDA-MB-231 cells and related mechanisms were investigated. The results showed that the survival rate of MDA-MB-231 cells treated with EECU was significantly inhibited in a concentration-dependent manner, which was associated with the induction of apoptosis. EECU-induced apoptosis was associated with the activation of caspase-8 and caspase-9, which initiate extrinsic and intrinsic apoptosis pathways, respectively, and caspase-3, a representative effect caspase. EECU suppressed the expression of the inhibitor of apoptosis family of proteins, leading to an increased Bax/Bcl-2 ratio and proteolytic degradation of poly (ADP-ribose) polymerase. EECU also enhanced the loss of the mitochondrial membrane potential and cytochrome c release from the mitochondria to the cytosol, along with truncation of Bid. In addition, EECU activated AMP-activated protein kinase (AMPK), and compound C, an AMPK inhibitor, significantly weakened EECU-induced apoptosis and cell viability reduction. Furthermore, EECU promoted the generation of reactive oxygen species (ROS), which acted as upstream signals for AMPK activation as pretreatment of cells, with the antioxidant N-acetyl cysteine reversing both EECU-induced AMPK activation and apoptosis. Collectively, these findings suggest that EECU inhibits MDA-MB-231 adenocarcinoma cell proliferation by activating intrinsic and extrinsic apoptotic pathways, which was mediated through ROS/AMPK-dependent pathways.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.507-517
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• 2018

The probability of T/S cargo volume to decrease is the most notable problem associated with inappropriate mix of terminal operators in Busan port. Other problems include, the deterioration of the national carriers' competitiveness from non-operation of own terminal, excessively high proportion of financial operators in the engagement of operation which may result in their passiveness in timely investment, additional cost burden to carriers' in the handling inter-terminal T/S cargo transportation and inefficiency in terminal operation by the multiplicity of operators proved to be same recognized as so through the analysis. Therefore, in order to provide solutions for the problems and to strengthen Busan port's competitiveness, this research suggests the restructuring of operators mix as follows. To achieve sustainable growth of T/S cargo, global carriers' participation in terminal operation should be of utmost priority. To enhance the operational efficiency, the operators should be integrated. Similarly, the integration of operators will play a key role in verifying that national carriers' own terminal operation is an important factor in raising its competence. Finally, BPA's active engagement in the entire operation of port is also critical in public-oriented operation of the port. Whereas in the interactive analysis by taking the merits of Busan port into consideraion, global carrier's participation in operation, integration of operators and BPA's engagement in operation proved to contribute to the increase of T/S cargo and strengthening of operational efficiencies of Busan port.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.84-107
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• 2018

Cheommojik is a pile cloth, a type of textile whose surface is covered with short piles. The term chaedam was used during the late Joseon dynasty to refer to pile cloth rugs, while the terms yoongjeon, dantong and yangtanja were used in the early twentieth century. Various documents, newspaper articles and photographs confirm that pile cloth rugs were used by the general public as well as the royal family from the late Joseon dynasty onward, and that there were domestic manufacturers of such rugs at that time. This study investigated six pile cloth rugs that were produced after the late Joseon dynasty, five of which feature Persian knots made of cut pile, the other being made with the loop pile method. The cut pile rugs are rectangular in shape and measure between 72-98cm by 150-156cm; and they are decorated in the middle with patterns of butterfly, deer, and tiger or the ten longevity symbols, and along the edges with patterns composed of 卍 symbols. The ground warp of all six rugs are made from cotton yarn, while the ground weft is made of cotton yarn on three pieces, wool on one piece and cotton and viscose rayon. The ground weft yarn from four pieces are Z-twist yarn made with two or more S-twist cotton yarn. Four to six colors were used for the pile weft, all being natural colors except for red. Two or more S- or Z-twist yarn were twisted together in the opposite twist for the pile weft, with the thickness determining the number of threads used. Six or more weft threads were used to make the start and end points of the rug; and the ground warp ends were arranged by tying every four of them together. For the left and right edges, three or more threads were wrapped together into a round stick-like form, and the second and third inner ground warps from the edges were stitched on to the wrapped edge. For the loop pile, loops were made in the direction of the warp; the ground warp and the ground weft may have been made with cotton, the pile warp with wool yarn. An analysis of the components of three rugs was conducted to determine which types of animal hair were used for the pile weft. Despite some inconclusive results, it was revealed that goat hair and fat-tailed sheep hair were used, raising the possibility that various kinds of animal fur were used in the production of pile cloth rugs. The six rugs examined in this study are estimated to have been made between the late 1800s and the early 1900s. Although the manufacturer of the rugs cannot be confirmed, we concluded that the rugs were produced in Korea after referring to the documentation of the domestic production of pile cloth rugs during the aforementioned period and the form and placements of the patterns on the rugs.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.61-67
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• 2019

This study was conducted to investigate the effect of supplementary feeding levels on livestck and forage productivity and grazing intensity in Elk stags (Cervus canadensis). A fifteen 2-year-old Elk stags about 195 kg were randomly assigned to one of three dietary treatments (five animals per treatment). The dietary treatments consisted of a feeding concentrate of 1.0% of body weight (T1), 1.5% of body weight (T2) and 2.0% of body weight. Total dry matter intake (TDMI) was increased with increased with an increasing supplementary feeding levels. Average daily gain (ADG) were significantly increased with an increasing supplementary feeding levels (p<0.05) and reached a maximum on July and was lower in spring than autumn. The velvet antler production was no differences among treatment groups. Forage productivity of pasture and crude protein content were highest on May and decreased thereafter, however, crude fiber content was the reversed. The grazing intensity of Elk stags was increased in spring (38 to 59 head per ha) than summer and autumn (13 to 32 head per ha). The average grazing intensity of Elk stags ranged from 21 to 34 head per ha, which is affected by supplementary feeding levels. This result suggests that feeding supplementary diet at 1.5 % of body weight was needed to maintain the stable wight gain in antler growing periods and control the proper grazing intensity of Elk deer stags.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.375-388
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• 2019

Accurate evaluation of sea-to-air $CO_2$ flux and its variability is crucial information to the understanding of global carbon cycle and the prediction of atmospheric $CO_2$ concentration. $fCO_2$ observations are sparse in space and time in the East Sea. In this study, we derived high resolution time series of surface $fCO_2$ values in the southwest East Sea, by feeding sea surface temperature (SST), salinity (SSS), chlorophyll-a (CHL), and mixed layer depth (MLD) values, from either satellite-observations or numerical model outputs, to three machine learning models. The root mean square error of the best performing model, a Random Forest (RF) model, was $7.1{\mu}atm$. Important parameters in predicting $fCO_2$ in the RF model were SST and SSS along with time information; CHL and MLD were much less important than the other parameters. The net $CO_2$ flux in the southwest East Sea, calculated from the $fCO_2$ predicted by the RF model, was $-0.76{\pm}1.15mol\;m^{-2}yr^{-1}$, close to the lower bound of the previous estimates in the range of $-0.66{\sim}-2.47mol\;m^{-2}yr^{-1}$. The time series of $fCO_2$ predicted by the RF model showed a significant variation even in a short time interval of a week. For accurate evaluation of the $CO_2$ flux in the Ulleung Basin, it is necessary to conduct high resolution in situ observations in spring when $fCO_2$ changes rapidly.