• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.457-467
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• 2019

To investigate the long-term variation characteristics of nutrients in the east coast of Korea, water temperature, salinity, dissolved oxygen, and nutrients were measured at three stations of Sokcho, Jukbyeon and Gampo coasts for five years from 2013 to 2017. For five years, the water temperature of the East Sea coast was in the range of $1.2{\sim}28.8^{\circ}C$, the salinity was in the range of 30.63~34.79 and the dissolved oxygen (DO) was in the range of 3.53~7.64 mL/L. Distribution and variation of the water environment factors in the study area were determined by the vertical stratification of water column and distribution of water temperature. The high DO concentration in Sokcho coast From 2015 to August 2016 is presumed to be the result of the southward inflow of North Korean Cold Water (NKCW). Concentrations of dissolved inorganic nitrogen (DIN, $NH_4-N+NO_2-N+NO_3-N$) ranged $0.11{\sim}24.19{\mu}M$, phosphate concentration ranged $0.01{\sim}1.75{\mu}M$, and silicate ranged $0.17{\sim}32.80{\mu}M$. The N:P ratio was in the range of 0.7~54.3 (mean 15.2) and the N:P slope was in the range of 11.67~13.75. The N:P ratios in this study were lower than the Redfield ratio (16), indicating that nitrate did act as a limiting factor in phytoplankton growth. The correlation ($R^2$) of total N:P ratio was as high as 0.95, indicating that the effect of the surrounding land or non-point sources was not significant. In conclusion, the spatial and temporal variation of nutrients in the east coast of Korea was determined by the vertical mixing of water mass with thermocline and mainly affected by physical factors such as influx of external water masses and coastal upwelling, and the influences from inflows from the land were minimal.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.38-55
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• 2019

The purpose of this study is to clarify the historical flow of baekdong alloy's usage according to the alloying materials mentioned in document records. For this purpose, we first overviewed the use of copper as a base material for white copper alloys and other types of copper alloys. Baekdong is an alloy of copper and other metals and is currently defined as an alloy of copper and nickel. However, depending on the research subjects and time of the scholars, baekdong may be defined as a metal with over a certain percentage of tin added to copper, or as an alloy of tin, zinc, and lead with copper. There is disagreement regarding the interpretation of this term. Baekdong, which started to appear in the literature of the Three Kingdoms Period, has been steadily seen through the Goryeo and Chosun Dynasties to the modern period. It has been used in various ways, according to each age and culture, from the symbol of the office to trading goods, daily life goods, and money. In the literature, baekdong's alloying material is not only copper and nickel, which are currently defined as alloys, but it is the same in that copper is used as the base metal of the alloy, although it varies slightly from generation to generation. In addition to copper, tin, zeolite, and emerald, zinc and lead also appeared. It was found that baekdong, which means alloy, and baekdong, which means white metal, were mixed. Nickel, which is the alloy material of baekdong as it is currently defined, is a metal with a relatively high discovery time and is widely used as a material for modern industrial fields. Nickel was introduced into Korea at the end of the Joseon Dynasty, but its use is not known in detail. In this study, we examined the acceptance and use of nickel-based baekdong in articles of modern newspapers and in statistical data. Based on the experience of craftsmen, we estimated the period when nickel-based alloys were used in crafts. Material is a direct factor in the development and deterioration of technology, and the development of technology is the basis for the changing of civilizations and cultures. In this context, this study was to investigate baekdong with the material of alloys as a starting point.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.354-361
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• 2021

Understanding the phytotoxic mechanism of methyl bromide (MB), an essential fumigant during the quarantine and pre-shipment process, is urgently needed to ensure its proper use and reduce international economic losses. In a previous study, two main MB-induced toxic mechanisms such as reactive oxygen species (ROS) and auxin distribution were selected by analyzing transcriptomic analysis. In the study, a 3-week-old A. thaliana was supplied with 1 mM ROS scavengers [N-acetyl-L-cysteine (NAC) or L-glutathione (GSH)] and 1µM indole-3-acetic acid(IAA) three times every 12 h, and visual and gene expression assessments were performed to evaluate the reduction in phytotoxicity by supplements. Phytotoxic effects on the MB-4h exposed group were decreased with GSH application compared to the other single supplements and a combination of supplements at 7 days post fumigation. Among these supplements, GSH at a concentration of 1, 2, and 5mM was suppled to A. thaliana with MB-fumigation. During a long-term observation of 2 weeks after the fumigation, 5 mM GSH application was the most effective in minimizing MB-induced phytotoxic effects with up-regulation of HSP70 expression and increase in main stem length. These results indicated that ROS was a main key factor of MB-induced phytotoxicity and that GSH can be used as a supplement to reduce the phytotoxicity of MB.

• Journal of the Korea Society of Computer and Information
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• v.26 no.3
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• pp.155-165
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• 2021

The measures to extend local education autonomy are as follows: First, it is necessary to correct the confusion of the legal system of the local education autonomy system. For this, Article 12, Paragraph 2 and 4 of the 「Special Act on Local Autonomy and Decentralization, and Restructuring of Local Administrative Systems」 which state that "The State shall endeavor to consolidate systems for autonomy in education and local government" and "The implementation of autonomy in education and the autonomous police system shall be prescribed separately by Acts" should be deleted. Second, it is necessary to clarify unnecessary legal matters and regulatory measures for unification at the national level and to proactively consider the introduction of the legal trust system, in which education affairs are designated as local governments' own work and the state carries out specific affairs. The decentralization of local education finance is a key factor for the development of local education autonomy, and it requires the transfer of authority and resources to the region, and the enhancement of local autonomy and corresponding responsibility. First, the ratio of special grants must be adjusted further (from 3% to 2%) or the ratio of national policy projects must be lowered. Second, the provision that requires a consultation with a mayor/governor when making a budget covered by transfers from general accounts should be deleted. Third, it is necessary to remove the elements that limit the authority of city and provincial councils. Fourth, it is necessary to integrate the national education tax and the local education tax to create the education autonomy tax (tentative name) for only one independent purpose. Fifth, it is necessary to strengthen the distribution of the total amount of grants and abolish the settlement regulations for the measurement items of standard financial demand. Sixth is the expansion of the participation of stakeholders and experts in the grant distribution process. Seventh, it is necessary to establish a long-term employment system by designating the education finance field as a special field. Eight is the expansion of cooperative governance.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.100-107
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• 2021

Along with an increase in the frequency of high-concentration fine particulate matter in Korea, interest and research on ammonia (NH₃) are actively increasing. It is obvious that agriculture has contributed significantly to NH₃ emissions. However, studies on the long-term effect of fertilizer use on the ambient NH₃ concentration of agricultural land are insufficient. Therefore, in this study, NH₃ concentration in the atmosphere of agricultural land was monitored for 11 months using a passive sampler. The average ambient NH₃ concentration during the total study period was 2.02 ㎍ m^-3 and it was found that the effect of fertilizer application on the ambient NH₃ concentration was greatest in the month immediately following fertilizer application (highest ambient NH₃ concentration as 11.36㎍ m^-3). After that, it was expected that the NH₃ volatilization was promoted by increases in summer temperature and the concentration in the atmosphere was expected to increase. However, high NH₃ concentrations in the atmosphere were not observed due to strong rainfall that lasted for a long period. After that, the ambient NH₃ concentration gradually decreased through autumn and winter. In summary, when studying the contribution of fertilizer to the rate of domestic NH₃ emissions, it is necessary to look intensively for at least one month immediately after fertilizer application, and weather information such as precipitation and no-rain days should be considered in the field study.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.188-197
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• 2020

Termites play an important role as decomposers of the forest ecosystem, while simultaneously causing enormous damage to wooden structures. Currently, two species of subterranean termites have been reported in Korea, and termite damage to historical wooden buildings is occurring nationwide due to climate change, forest fertility, and the locational characteristics of historical wooden buildings. Subterranean termites make their nests underground or inside timber. Termites move underground and access wooden structures through the lower parts of the buildings, adjacent to the ground. Once termites attack the wooden structures, it not only spoils the authenticity of cultural heritage structure, but also hampers structural stability due to the decrease in the strength of the material. Therefore, it is important to prevent termite damage before it occurs. Chemical treatments are mainly used in Korea to control and prevent the damage. In foreign countries, physical barriers are also used to prevent entry to wooden buildings, along with chemical treatments. Physical barriers involve installing nets or particles that termites cannot pass through in the lower part of the building, around the pipes, and between the edges of the building or exterior walls and interior materials. Advantages of a physical barrier are that it is an eco-friendly method, maintains long-term effect after installation, and does not require the use of chemical treatments. Prior to applying physical barriers, studies into the characteristics of termite species must be undertaken. In this study, we evaluated the minimum passage size that each caste of Reticulitermes speratus kyushuensis can move through. We found that workers, soldiers, and secondary reproductive termites were able to pass through diameters of 0.7mm, 0.9mm, and 1.1mm respectively. Head height of termites was an important factor in determining the minimum passing size. Results from the current study will be used as a basis to design the mesh size for physical barriers to prevent damage by termites in historical wooden buildings in Korea.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.48-67
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• 2021

Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

• Journal of Gastric Cancer
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• v.22 no.1
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• pp.67-77
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• 2022

Purpose: Tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) are standard adjuvant chemotherapies (ACs) administered after gastrectomy to patients with stage II or III gastric cancer. However, the efficacy of AC in elderly patients remains unclear. The objective of this retrospective multicenter cohort study was to compare the efficacies of S-1 and CAPOX AC in patients aged ≥70 years. Materials and Methods: Nine hundred eighty-three patients who were treated with AC using S-1 (768 patients) or CAPOX (215 patients) were enrolled in this study. Each patient underwent AC after curative gastrectomy for stage II or III gastric cancer at one of 27 hospitals in the Republic of Korea between January 2012 and December 2013. Relapse-free survival (RFS) and overall survival (OS) were analyzed according to AC regimen and age group. Results: Of the 983 patients, 254 (25.8%) were elderly. This group had a similar RFS (P=0.099) but significantly poorer OS (p=0.003) compared with the non-elderly group. Subgroup analysis of the non-elderly group revealed no AC-associated differences in survival. Subgroup analysis of the elderly group revealed significantly better survival in the S-1 group than in the CAPOX group (RFS, P<0.001; OS, P<0.001). Multivariate analysis revealed that the CAPOX regimen was an independent poor prognostic factor for RFS (hazard ratio [HR], 1.891; 95% confidence interval [CI], 1.072-3.333; P=0.028) and OS (HR, 2.970; 95% CI, 1.550-5.692; P=0.001). Conclusions: This multicenter observational cohort study found significant differences in RFS and OS between S-1 and CAPOX AC among patients with gastric cancer aged ≥70 years.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.237-250
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• 2020

The purpose of this study was to investigate the relationship between the performance factors of dance performance and the intention to revisit the audience, and to investigate the structural relationship between viewing satisfaction and viewing value. For data processing, SPSS Ver. 21.0 and AMOS Ver. The program of 21.0 was used. Structural relationships were analyzed using a two-step approach, and the significance of the effects was verified using bootstrapping. In addition, a full mediating effect and a partial mediating effect were presented using the three-step regression analysis mediating effect. The results of the study are as follows. First, it was found that the viewing factors influenced the viewing satisfaction and the viewing value. Second, it was found that viewing satisfaction had an intention to revisit and influenced the viewing value. It was also found that the viewing value had an effect on the intention to revisit. Third, in the relationship between the viewing factors of the dance performance and the viewing value, it was found that the viewing satisfaction had a partial mediating effect. Fourth, it was found that the attendance factor of the dance performance was not related to the intention to revisit. However, it was found that the satisfaction of viewing and the value of viewing had a complete mediating effect in relation to the viewing factors of dance performances and the intention to revisit. Through these studies, the dance performance should overcome the inherent limitations of space-time limitations and present basic data for establishing a mid- to long-term marketing strategy that can respond quickly.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.3
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• pp.1-9
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• 2022

This study compared and reviewed the recognition determinants by applying the OECMs criteria, focusing on old big trees, plant of natural monument that are natural heritage under the national heritage system of the Cultural Heritage Administration, and the results are as follows. First, among the protected areas designated and managed by government agencies according to each protection purpose, it is necessary to actively introduce new conservation measures, OECMs, to fulfill the Biodiversity strategy for 2030 while the land area is already saturated. Second, the OECMs are geographically defined areas(CBD, 2018), not currently recognized as a protected areas, governed and managed in a way that achieves positived sustained and effective contribution to in situ conservation of biodiversity. Since the selection of term, the scope of application criteria, and the context of interpretation are inevitably different, it is necessary to separately legislate and establish related laws of the OECMs suitable for each country's situation. Third, as a result of reviewing the OECMs criteria for plant of natural monument, the final 58 potential resources were recognized. Important elements among the OECMs criteria are that buffer zones should be spaced apart from designated zones to secure a certain area, and that economic activities through commercial production should not occur and meet biodiversity standards. Among the potential candidates, 23 areas were analyzed to be geographically isolated and independent, such as Forest of Oriental Arborvitae in Do-dong, Daegu, and forest types such as Carstor Aralia of Gungchon-ri, Samcheok and Forest of Common Camellias in Maryang-ri, Seocheon. As a result of reviewing the application of OECMs criteria for plant of natural monument, it was confirmed that the functions as a traditional uses were specialized among the values of biodiversity, and ecosystem services and cultural and spiritual values were inherited through Korea's unique culture of old big trees and Dangsan ritual. In terms of biodiversity criteria, it can be used as an important factor in connecting human and natural ecosystem networks without the discovery of new species.