• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.54-61
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• 2021

This work describe an efficient method for the shoot induction and plant regeneration of seedling-derived apical bud explants of Tilia mandshurica Rupr. & Maxim. The highest rate of shoot induction (82.2%) was obtained when apical bud explants from juvenile seedlings (5 months old) were cultured on Murashige and Skoog (MS) medium containing 1.0 mg/L 6-benzylaminopurine (BAP). However, apical bud explants obtained from mature trees (12 years old) did not produce any shoots, even with BAP supplementation. Among the three cytokinins tested for shoot multiplication (BAP, zeatin, and kinetin), BAP was the most effective; the highest number of shoots per explant (2.1) was observed on MS medium supplemented with 1.0 mg/L BAP. In contrast, the longest average shoot length (3.0 cm) was observed after growth on MS medium with 2.0 mg/L zeatin. No multiplication occurred when apical bud explants were cultured with kinetin-supplemented media. During rooting of in vitro-elongated shoots, the highest rooting rate (100%) was observed in half-strength MS medium supplemented with 0.5 ~ 1.0 mg/L indole-3-butyric acid (IBA) or 3.0 mg/L 1-naphthaleneacetic acid (NAA). During the acclimatization process, plantlets that were rooted on the IBA (0.5 mg/L)-supplemented medium had the highest survival rate (100%) and maximum root length (18.5 cm). These findings suggest that a low concentration (0.5 mg/L) of IBA is appropriate for the rooting and acclimatization of T. mandshurica. Plants were successfully transferred to the greenhouse with a 100% survival rate. This protocol will be useful for the large-scale propagation of Tilia species.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.10
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• pp.1432-1440
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• 2022

Recently, as Virtual Desktop Infrastructure(VDI) is widely used not only in office work environments but also in workloads that use high-spec multi-core-based applications, the requirements for real-time and stability of VDI are increasing. Accordingly, the display protocol used for remote access in VDI and performance optimization of virtual machines have also become more important. In this paper, we propose two ways to configure desktop virtualization for multi-core-based application operation. First, we propose a codec configuration of a display protocol with optimal performance in a high load situation due to multi-processing. Second, we propose a virtual CPU scheduling optimization method to reduce scheduling delay in case of CPU contention between virtual machines. As a result of the test, it was confirmed that the H.264 codec of Blast Extreme showed the best and stable frame, and the scheduling performance of the virtual CPU was improved through scheduling optimization.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.261-273
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• 2022

This study aims to analyze whether facilities linked to the inside and outside of the station affect the revitalization of commercial spaces inside the station where individual rental stores are clustered. Rent, which can replace sales, was set as the determining factor for revitalization. In addition to the variables related to sales, culture, office work/residential, public institutions, and transportation facilities, the independent variables were the number of daily passengers, which is a location factor of the station, and the product sales business, which accounts for the largest number of industries in the commercial space inside the station. As a result of regression analysis, it was proved that rent has an effect on product sales business, linked sales facilities, transportation facilities, and the number of passengers on board. These results indicate that the formation of sales products that can increase purchasing power and the direction of facility linkage that can increase the inflow population into the station are needed to revitalize commercial spaces in the station. In this study, the establishment of a living-friendly SOC for residents' convenience daily life was suggested as a policy management plan for stations with a high vacancy rate due to reduced vitalization.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.477-489
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• 2021

This study was conducted to confirm whether organization culture unbalance plays a role as a moderating variable on the mediation process that protean career orientation influences subjective career success through continuous learning activity. To this end, a survey was carried out on 276 office workers with more than 5 years of work experience in large companies, and the data were analyzed using SPSS 25 and Process Macro v3.5. The results showed that continuous learning activity mediates the relationship of protean career orientation affecting subjective career success, but moderating effect of organizational culture unbalance and the moderated mediation effect were not statistically significant. However, statistical significance was found on the moderating effect of organizational culture unbalance on the mediation process, that 'self-direction', protean career orientation's sub-factor, affects subjective career success and its' sub-factor 'employability', and 'career satisfaction' through continuous learning activity. The significance and limitations of our findings are also discussed.

• Journal of dental hygiene science
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• v.22 no.3
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• pp.180-190
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• 2022

Background: Like direct infection from COVID-19, psychological concern about infection could affect health. Concern about COVID-19 infection was associated with individual habits to practice rules for preventing infection. Therefore, this study aimed to check occupational types and whether to practice tooth brushing after lunch depending on the occupation of economic workers and find correlations between concerns about infection due to COVID-19 pandemic and tooth brushing after lunch. Methods: The raw data was from the community health survey conducted in 2020. Among 229,269 adult participants aged 19 years and older, 138,970 economic workers were included in the final analysis. The chi-squared test was used to find differences in psychological concerns due to the COVID-19 pandemic. According to the participants, the rate of practicing tooth brushing after lunch was based on COVID-19-related psychological concerns. Multiple logistic regression analysis was conducted to check the influence of psychological concerns due to the COVID-19 pandemic on the rate of practicing tooth brushing after lunch. Results: According to occupational classifications, professionals and office workers and career soldiers had 1.551- and 1.581-times higher practicing rates than managers, respectively, whereas machine operators, agricultural and fishery sector workers, and daily laborers had lower practicing rates. Regarding COVID-19-related psychological concerns, the group with a lower concern about infection had a 1.076 times higher practicing rate than that with greater concern. The group with greater concern about blame from neighbors had 1.119 times higher practicing rate than that with lower concern. Conclusion: The correlations between higher economic workers' concerns about infection and blame from neighbors and higher recognition of the necessity to prevent COVID-19 and practice tooth brushing after lunch were confirmed. It is necessary to prepare measures for practicing tooth brushing after lunch suitable to the characteristics of occupational types and work environments of economic workers.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.873-882
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• 2022

Purpose: The purpose of this paper is to analyze accidents and potential risks occurring at container terminals and to conduct on safety management plans tailored to container terminals. Method: A model for establishing a safety management plan is presented through a case study of container terminal risk assessment and literature analysis. Result: According to the 'Statistics of Accidents in the Harbor Handling Industry', 2,800 people were killed or injured during port work for 10 years from 2011 to 2021. This corresponds to an occupational accident rate of one person every 1.5 days. As a method of improving these accidents and disasters, a highly effective safety management plan should be established to prevent the recurrence of accidents in accordance with the Special Act on Port Safety. It is proposed to establish a safety management plan that reflects the risk assessment of container terminals, safety organization, safety budget, safety rules, and safety education.

• Anxiety and mood
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• v.18 no.2
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• pp.80-91
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• 2022

Objective : Hospital workers' mental health has deteriorated because of the ongoing COVID-19 pandemic. The purpose of this study was to investigate the impact of the prolonged COVID-19 pandemic on the mental health of hospital workers and its determinants. Methods : Two surveys were conducted among employees working in a hospital that received COVID-19 patients from the early phase of the pandemic in South Korea. Data on demographics, perceived threat, workplace evaluation, resilience, and mental health status were collected using the Korean General Health Questionnaire-20 in the initial phase (February 2020) and during the third wave of COVID-19 (December 2020) for 467 and 545 workers, respectively. The mental health of hospital workers in the two phases was compared, and the risk and protective factors during the third wave were investigated. Results : The proportion of patients in the psychiatric high-risk group increased from 2.8% in the initial phase to 11.4% during the third wave. The perceived threat, workplace evaluation, and resilience of respondents deteriorated. Risk factors for mental health during the third wave included the perceived threat items of job stress, loss of control, and considering resignation. Protective factors included presence of children, workplace satisfaction, and hardiness in resilience. Conclusion : Hospital workers' mental health deteriorated as the pandemic progressed. General stress and tension such as job stress, loss of control, considering resignation rather than COVID-19-specific stress had negative effects on mental health of hospital workers. Therefore, care for work stress itself can be helpful to maintain the mental health of hospital workers. Also, governance to improve workplace satisfaction or hardiness in resilience can be a potential protective factor for hospital workers' mental health during the prolonged pandemic.

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.4
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• pp.33-40
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• 2022

Sharehouse has been supplied as an alternative to solving the steadily increasing one-room housing problem of single-person households every year, and it is necessary to investigate the satisfaction of residents who actually live in sharehouse through P.O.E. Therefore, this study analyzed priror researches related to the existing one-person households, sharehouses, and satisfaction surveys, and summarized indicators with high relevance and frequency to derive satisfaction survey factors that can clearly evaluate the improvement architectural plan of sharehouses. As a result, it was classified into 4 items in the 'general information' category to investigate the status, housing rental type, and housing cost of the sharehouse, 15 factors in the 'peripheral environment' category to evaluate the safety, 3 factors in the 'community' category, and 17 factors in the space (facility) and service category. In the "General Information" section, the overall one-person housing satisfaction, desired sharehouse type, housing rental type, housing cost, and living expenses were reduced. In the "Surrounding Environment", accessibility to public office, accessibility to cultural facilities, accessibility to medical facilities, accessibility to work and school, convenience stores, noise pollution and safety. In addition, in the "community" section, it consists of interactions with various people, relationships with housemates and in the "space (facilities) and service" section, heating, waterproof, soundproof, ventilation, moisture and condensation blocking, facility management, interior, room size, built-in furniture, storage space, laundry, parking. Most of the scales for each factor were 5-point Likert scales, allowing evaluation of the degree of satisfaction, and some factors presented criteria to induce structured answers. Therfore, it is expected that the survey will be conducted on residents who actually live by deriving factors for the satisfaction survey of one-person households living in the sharehouse, and the current status of the sharehouse will be identified, and the degree of satisfaction will be analyzed to be used for research.

• Smart Structures and Systems
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• v.31 no.5
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• pp.485-500
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• 2023

Machine learning-based structural health monitoring (ML-based SHM) methods are researched extensively in the recent decade due to the availability of advanced information and sensing technology. ML methods are well-known for their pattern recognition capability for complex problems. However, the main obstacle of ML-based SHM is that it often requires pre-collected historical data for model training. In most actual scenarios, damage presence can be detected using the unsupervised learning method through anomaly detection, but to further identify the damage types would require prior knowledge or historical events as references. This creates the cold-start problem, especially for new and unobserved structures. Modal-based methods identify damages based on the changes in the structural global properties but often require dense measurements for accurate results. Therefore, a two-stage hybrid modal-machine learning damage detection scheme is proposed. The first stage detects damage presence using Principal Component Analysis-Frequency Response Function (PCA-FRF) in an unsupervised manner, whereas the second stage further identifies the damage. To solve the cold-start problem, mode shape assessment using the first mode is initiated when no trained model is available yet in the second stage. The damage identified by the modal-based method would be stored for future training. This work highlights the performance of the scheme in alleviating the cold-start issue as it transitions through different phases, starting from zero damage sample available. Results showed that single and multiple damages can be identified at an acceptable accuracy level even when training samples are limited.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.65.1-65.1
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• 2021

The Donggungilgi (東宮日記) is the daily records of the Siganwon (侍講院), which was a royal office in the Joseon dynasty that took charge of the education for the crown prince who dwelled in the Donggung (East Palace). This literature contains records of meteorological and astronomical observations as well as educational matters. The Sohyeon-Donggungilgi (昭顯東宮日記) includes records from 1625 to 1645, when Prince Sohyeon, the first son of King Injo (仁祖), was the crown prince. We investigate the records of solar halo observations in the Sohyeon-Donggungilgi. For consistency, we restrict our investigation to the period before the second Manchu invasion of Korea (i.e., 1625 to 1635). We extract 2,684 records and classify them into ten events according to the terms in their descriptions. The largest and smallest number of observation records are for the Hun (暈) and Geuk (戟) events (1,794 and 7 records, respectively). To verify what each event represents in modern atmospheric terms, we refer to historical documents of the Seoungwanji (書雲觀志, Treaties on the Bureau of Astronomy) and Cheonmundaeseong (天文大成, Great Achievements in Astronomy). We also calculate the solar altitude based on the observation hour and compare the descriptions to compute simulations provided by Arbeitskreis Meteore e.V.. We find that the descriptions of the Hun, Junghun (重暈), Yi (珥), and Baekhonggwanil (白虹貫日) events indicate a 22˚ halo, 22˚ and 46˚ halos, a parhelion, and a parhelic circle, respectively, Alternatively, we estimate that the Gwan (冠), Dae (戴), Bae (背), Li (履), and Gyohun (交暈) events describe arcs tangent to a 22˚ or 46˚ halo such as a upper or lower tangent arc, a circumzenithal arc, or a parry arc. We suggest that further studies are required for the Geuk event because the descriptions of this event differ from both documents referred to this study. In the sense that the number of observation records of the Geuk event is the smallest, however, this event may describe a rare phenomenon. We believe that this work will contribute to the study of historical records of solar or lunar halos.