• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.271-278
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• 2021

Azolla is a genus of small aquatic ferns native to Asia, Africa, and America. Azolla is potentially significant as a nitrogen source in agriculture, particularly in conjunction with rice (Oryza sativa L.) cultivation. In addition, Azolla may either control weeds or act as a weed depending on management; therefore, we aimed to determine the effect of Azolla incorporation on weed (e.g., Monochoria vaginalis, Rotala indica, Aeschynomene indica, and Cyperus amuricus) control and its other benefits during rice cultivation. The effects of Azolla on weed emergence were evaluated based on plot area coverage by the Azolla mat, which appears as a green sheet over water, and the rate of weed emergence in paddy field. Weed occurrence was investigated 40 days after Azolla inoculation. Soil samples from the experimental plots were collected following harvest in 2014-2015, and analyzed. Moreover, rice growth, yield, and grain quality were measured. Azolla suppressed weed growth by 72%. Azolla mat incorporation in rice fields suppressed weed growth by over 60%. In addition, Azolla promoted nitrogen fixation. Compared with nitrogen management using chemical fertilizers, Azolla incorporation showed the potential for various positive effects, including the improvement of soil fertility by increasing total nitrogen, and organic matter content. Rice grown with Azolla maintained its yield without additional herbicide treatment. Moreover, the palatability of cooked rice was better when grown with Azolla.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.6
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• pp.35-50
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• 2022

As the water shortage has become a noticeable issue due to climate change, forests play an importance role as the provider of water supply service. There is, however, little information about the relationships between the factors used in the estimation of water supply service and coarse pore fraction of forest soil which determines the potential of water supply. To find out whether there would be an amelioration in the scoring system of water supply service estimation, we examined all factors except meteorological one and additionally, analyzed 4 extra factors that might be related with coarse pore fraction of soil. A total of 2,214 soil samples were collected throughout South Korea to measure coarse pore fractions from 2015 to 2020. First, the result of average coarse pore fraction of all samples showed 32.98±6.59% which was consistent with previous studies. And the results of non-parametric analysis of variance indicated that only two of eleven factors that was used in the scoring system matched the results of coarse pore fraction of forest soils. Tree canopy coverage showed no difference among categories, and slope also showed no significance at level of 0.05 in the linear regression analysis. Additionally, the applicability of 4 extra factors were confirmed, as the result of coarse pore fractions of soil samples were different for various categories of each factor. Therefore, the scoring system of water supply service of forest should be revised to improve accuracy.

• Journal of the Korean Burn Society
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• v.23 no.2
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• pp.54-59
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• 2020

Purpose: A fourth degree burn is a full-thickness burn of the skin usually accompanied by damage to deep structures and commonly results in extensive damage to surrounding tissues which makes the treatment of the wound difficult. Coverage of these wound using free flap is known to effective but not commonly used. The purpose of our study is to review our experience and suggest early application of free flap surgery. Methods: A retrospective review was performed from 2010 to 2019, on a total of 34 fourth degree burn patients undergone free flap surgery as primary treatment in our hospital. We reviewed the location of the injury, etiology, TBSA (%), Presence of osteomyelitis, flap choice, complications, period of injury to surgery and healing. Results: Using free flap as a primary reconstrcuction, the outcome is satisfactory. The treatment period was shortened, and there was less loss of function due to complications. Also the incidence of osteomyelitis and amputation was significantly low. Conclusion: Applying free flap surgery as soon as possible in fourth degree burns is effective, such as reducing complications such as infection, reducing amputation, shortening treatment period, and preventing severe sequelae.

• Korea Journal of Hospital Management
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• v.27 no.4
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• pp.22-35
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• 2022

Purpose: Physician's occupational burnout has been a very important issue that can cause negative consequences not only for individual's physical and mental health, but also for patient's health and the overall national healthcare system. For the reason, this study confirmed how consultation length and the number of outpatients affect physician's occupational burnout in the medical environment. Methodology: In the study, the data of '2020 Korean Physician Survey' conducted by Korean Medical Association(KMA) was used for the analysis, and a total of 4,215 physicians were selected as study samples. The differences in the degree of occupational burnout according to the physicians' general characteristics were confirmed through uni-variate analysis, and also a regression analysis was conducted to confirm the effects of consultation length and the number of outpatients on physician's occupational burnout. Findings: As a result. the overall degree of physician's occupational burnout decreased(𝛽=-0.051, p<0.01) as the consultation length increased. Specifically, the physician's emotional exhaustion increased(𝛽=0.051, p<0.01), while the reduction of accomplishment decreased(𝛽=-0.131, p<0.001). Furthermore, the overall occupational burnout decreased(𝛽=-0.047, p<0.01) as a proportion of advice and education during the consultation increased, and it had an effect on the decrease in depersonalization(𝛽=-0.045, p<0.01) and the reduction of accomplishment(𝛽=-0.065, p<0.001). At last, as the number of outpatients increased, the overall occupational burnout increased(𝛽=0.041, p<0.05) with more emotional exhaustion(𝛽=0.095, p<0.001), depersonalization(𝛽=0.065, p<0.001), and less reduction of personal achievement(𝛽=-0.081, p<0.001). Practical implication: Consequently, it is necessary to prevent physician's occupational burnout by ensuring sufficient consultation length and providing a medical environment to treat an appropriate number of patients. Therefore, national policies should expand health insurance coverage and compensate medical fees for sufficient consultation length that both patients and physicians can satisfy. It will ultimately contribute to ensuring the patients' health and improving the quality of national healthcare services.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.662-675
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• 2022

This study was intended to investigate and analyze the current status of the plant community structure in order to provide basic data for the systematic conservation and management of the Buxus sinica area appearing on the ridgeline connecting the Gyeokjabong(Mt.) and Keungiljae, on Bogildo Island. In consideration of location characteristics such as density, topography, and direction of B. sinica appearing in the shrub layers, a total of 26 sites were set as the survey area for representative vegetation communities or areas with changes in topography. According to DCA and TWINSPAN, it was classified into 6 communities, namely Carpinus turczaninovii-Deciduous broad-leaved, C. turczaninovii, C. turczaninovii-B. sinica, C. turczaninovii-Evergreen broad-leaved, Q. acuta, and D. trifidus-Q. acuta. The community dominated by C. turczaninovii maintains the status quo for the present moment, however, Q. acuta will dominate the surrounding area in the long term, so Q. acuta has high succesion potential. In the case of the Q. acuta and D. trifidus-Q. acuta communities, Q. acuta, known as the climax species of warm-temperate forests, will maintain dominant status. In a case of B. sinica, the community dominated by C. turczaninovii will remain in good status due to the topographical conditions, but the community dominated by Q. acuta growth difficulties are expected due to the high coverage. In the relationship between environmental factors and vegetation distribution, analysis showed that only soil pH affect vegetation distribution. Furthermore, the soil acidity (pH) was 3.78-5.30, the electrical conductivity was 0.186-0.543 dS/m, and the organic matter content was 2.25-2.89%.

• Journal of the Korean Society for information Management
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• v.40 no.2
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• pp.157-182
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• 2023

This study analyzed the structure and utilization of subject headings in the National Library of Korea Subject Headings List (NLSH) based on an analysis of subject headings assigned to 1,218,867 national bibliographies from 2003 to 2022. The findings of the study are as follows: Firstly, among all subject headings in the NLSH, there were 257,103 preferred terms, accounting for 50.2% of the total terms. Foreign language terms constituted 33% (169,466), while non-preferred terms comprised 12% (61,442). Among the preferred terms, 57,312 subject headings were used, accounting for 22.3%. However, it was observed that 54.7% (31,351) of these subject headings were assigned less than 5 times, indicating that only a small number of subject headings were frequently utilized. Secondly, the frequency of relationship indicators appeared in the order of RT, BT, and NT. The NLSH consisted of 12,602 top-level subject headings and 143,704 lowest-level subject headings, with a maximum depth of 17 levels. Thirdly, on average, 1.72 subject headings were assigned per bibliographic record. The number of subject headings assigned and the depth of the hierarchy increased for materials with more specific contents. Recent bibliographic records have been assigned more subject headings and deeper into the hierarchy of the NLSH. It was also found that the number of subject headings assigned per bibliography varied depending on the main class of KDC. Based on the findings, it is recommended to evaluate the coverage of terms in the NLSH, reorganize hierarchical relationships and depth of subject headings, and enhance the development of subdivisions within the NLSH.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.106-116
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• 2020

To examine distribution of the Zostera species growing naturally in Ulleungdo, scuba diving surveys using ships were conducted along the coast and inside the harbors of the island at the end of September 2019. In areas of seagrass occurrence, environmental factors such as nutrient concentrations in water column and sediment pore water, salinity, and sediment organic content were also analyzed. Zostera caulescens meadows appeared in the relatively deep waters (14-24 m MSL) of Cheonbu-ri, Jeodong-ri, Sadong-ri, and Namyang-ri in Ulleungdo, and the total seagrass coverage was approximately 4.9 ha. Approximately 0.9 ha of Zostera marina meadow was found at the depths of 3-5 m MSL within Hyeonpo-hang in Hyeonpo-ri. The average shoot density and biomass of Z. caulescens were 121.9±9.7 shoot m^-2 and 99.0±13.2 gDW m^-2, respectively, with no significant differences by location. The average shoot density and biomass of Z. marina were 193.8±18.8 shoot m^-2 and 102.6±6.8 gDW m^-2, respectively. The nutrient concentrations in the sediment pore water and sediment organic content in the seagrass meadows in Ulleungdo were lower than those in eelgrass meadows on the southern and eastern coasts of Korea. These results will provide useful basic information for the marine protected species, Z. caulescens and Z. marina, and for the conservation of the waters of Ulleungdo, which has been designated as a marine protected area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.393-403
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• 2008

While characteristics of topography, soil, and vegetation coverage were surveyed, also surface runoff and soil erosion for each rainfall event were measured to analyze effect of change of land cover conditions in mountain areas, Yangyang, directly after wildfire. Fifteen rainfall events were taken in total during the survey period. The result of this survey appeared that the amount of surface runoff and soil erosion are a great difference between plots with rapidly recovered vegetation and bare plots after wildfire. The burned plots where vegetation recovered rapidly generated two times or more of surface runoff and soil erosion than control plots, as burned plots with bare soil showed about ten times of surface runoff and sediment than control plots. The result of correlation analysis between main parameters of the surface runoff and soil erosion presented that rainfall factors and vegetation factors had significant effects on runoff and soil erosion. The sensitivity of runoff and soil erosion showed specially high correlation with vegetation indices. If the land surface disturbed by wildfire are recovered by natural vegetation as time passes, runoff and soil erosion may be decreased gradually. Because runoff and soil erosion in the areas with rare vegetation or bare soil are generated continuously, the discriminated mediation strategies would be established as condition of each region.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.1-11
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• 2024

Despite improvements in vaccine coverage, a resurgence of measles has been reported, especially in the infant and adult populations in recent years. We conducted a systematic review of seroprevalence studies conducted in the Western Pacific Region (WPR) to provide insights into seropositivity trends in different countries. This systematic review aimed to collect data from all available measles seroprevalence studies to characterize the differences in population immunity against measles in different countries. We searched the online databases PubMed and Embase to identify: 1) observational studies that investigated seroprevalence in all age groups, and 2) results reported as antibody levels. The following variables were extracted from different study arms: paper identification (title, first author, publication year), inclusion and exclusion criteria, study site, age of subjects, number of subjects, country/area, population, methods, and seropositivity (%). The search yielded a total of 69 studies included in the review. Among the 1-6-year-old group, seropositivity remained relatively high, at 81-100% in China, 86-94% in Korea, and 77-91% in Australia. In adolescents aged 7-18-years old, seropositivity was relatively constant in China and Australia over time; however, a decreasing trend was noted in Korea in 2011 (66%), 2014 (69%), and 2014 (50%) in this age group. A similar downward trend was observed among Korean adults aged 19-39 years in 2011 (74%), 2019 (71%), and 2019 (64%). Children are likely to be protected by universal vaccination programs in WPR countries and regions. However, susceptible individuals with waned immunity may be present among the adult population.

• Journal of the Korean earth science society
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• v.45 no.2
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• pp.111-120
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• 2024

Cloud coverage is a key factor in determining whether to proceed with observations. In the past, human judgment played an important role in weather evaluation for observations. However, the development of remote and robotic observation has diminished the role of human judgment. Moreover, it is not easy to evaluate weather conditions automatically because of the diverse cloud shapes and their rapid movement. In this paper, we present the development of a cloud monitoring program by applying a machine learning-based Python module "cloudynight" on all-sky camera images obtained at Miryang Arirang Astronomical Observatory (MAAO). The machine learning model was built by training 39,996 subregions divided from 1,212 images with altitude/azimuth angles and extracting 16 feature spaces. For our training model, the F1-score from the validation samples was 0.97, indicating good performance in identifying clouds in the all-sky image. As a result, this program calculates "Cloudiness" as the ratio of the number of total subregions to the number of subregions predicted to be covered by clouds. In the robotic observation, we set a policy that allows the telescope system to halt the observation when the "Cloudiness" exceeds 0.6 during the last 30 minutes. Following this policy, we found that there were no improper halts in the telescope system due to incorrect program decisions. We expect that robotic observation with the 0.7 m telescope at MAAO can be successfully operated using the cloud monitoring program.