• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.888-895
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• 2020

In the construction industry, off-site construction (OSC) is drawing attention as a production method due to changes in working hours and the supply and demand of manpower. In 1991, there was a policy of spreading and expanding the use of precast concrete (PC) apartment homes, but they have not been actively used so far since they were discontinued due to quality problems. In this study, policy tasks were analyzed to motivate the application of OSC-based PCs in the apartment housing sector, and policy directions were derived by conducting focus group interviews (FGI). Nine policies are suggested regarding the following topics: PC apartment supply quantity provision, priority application of public housing, priority supply of public housing, preferential floor area ratio, funding, tax support, improvement of business area structure, improvement of delivery method, factory certification system, and training of experts. The results of the FGIs are as follows. First, in order to revitalize PC apartment homes, leading efforts from the public sector are required. Second, rather than reorganizing the business sector or introducing a new delivery method, a policy direction that induces the strengthening of cooperation is desirable. Third, PC activation should be promoted on an institutional basis for securing appropriate construction costs and quality.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.343-348
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• 2022

This study aims to analyze the user experience of unmanned checkout counters perceived by consumers using SNS big data. For this study, blogs, news, intellectuals, cafes, intellectuals (tips), and web documents were analyzed on Naver and Daum, and 'unmanned checkpoints' were used as keywords for data search. The data analysis period was selected as two years from January 1, 2020 to December 31, 2021. For data collection and analysis, frequency and matrix data were extracted through Textom, and network analysis and visualization analysis were conducted using the NetDraw function of the UCINET 6 program. As a result, the perception of the checkout counter was clustered into accessibility, usability, continuous use intention, and others according to the definition of consumers' experience factors. From a supplier's point of view, if unmanned checkpoints spread indiscriminately to solve the problem of raising the minimum wage and shortening working hours, a bigger employment problem will arise from a social point of view. In addition, institutionalization is needed to supply easy and convenient unmanned checkout counters for the elderly and younger generations, children, and foreigners who are not familiar with unmanned calculation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.729-740
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• 2022

This study analyzed the effects of job stress and sleep disorders on sleepiness during the daytime for a night-shift urban railway crew. As a result of the analysis, measurements on a daytime sleepiness index were higher for the crew than those during other working hours, indicating that the degrees of sleepiness and drowsiness were severe. Afterwards, aromatic essential oils, which are generally known to help relieve sleep disorders and stress, were utilized to verify the effect on stress on night-shift workers. The experimental group treated with aromatherapy was found to show improved stress reduction and overall activity levels in the autonomic nervous system compared to an untreated control group. This study proves that night work by an urban railway crew negatively affects stress levels by increasing stress and negatively affects the autonomous nervous system, also showing that an aromatherapy treatment can be a good alternative to alleviate these conditions. The results of this study are expected to help prevent safety accidents by relieving the stress of nighttime workers.

• Journal of Family Resource Management and Policy Review
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• v.26 no.2
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• pp.19-36
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• 2022

The purpose of this study was (a) to identify latent profiles among employed Korean mothers of third graders based on work-family conflict, work-family enrichment, work-parenting conflict, and work-parenting enrichment, (b) to examine the antecedents of profile membership at the individual, family, work, and community levels, and (c) to investigate the differences in the various psychological outcomes across the profiles. The sample of 451 married employed mothers was a subset of data from the 10th Wave of the Panel Study of Korean Children, which was collected in 2017 when the focal child was in the third grade. Our latent profile analysis suggested a three-profile model that comprised enriched (11.91%), moderate (47.85%), and mixed (40.24%) profiles. The significant antecedents of profile membership were subjective health status, the child's adjustment to school, working hours, the community's suitability for childrearing, and satisfaction with community service facilities. Regarding psychological outcomes, the levels of life satisfaction, marital satisfaction, and job satisfaction were higher in the following order: enriched, moderate, and mixed profiles. The levels of depressive symptoms were in the reverse order: mixed, moderate, and enriched profiles. This study contributes to a comprehensive understanding of the literature on work-family interactions by considering various predictors and outcomes at multiple levels.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.91-102
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• 2022

Many industries are being severely damaged by COVID-19, a respiratory infection that has recently been prevalent around the world. In particular, for workers in the construction industry, it is impossible to work from home, and if an outbreak on a construction site is confirmed, it can lead to great damage. Accordingly, the government has drafted 「Guidelines for Response to Construction Sites for Prevention and Spread of COVID-19」. In addition, domestic and foreign research about COVID-19 in the field of construction sites is being actively conducted. However, Korea has lacked studies on the effectiveness of the countermeasures in place at construction sites, or that reflect the opinions of construction site workers. Therefore, this study conducted a survey of construction site workers by dividing the construction of the COVID-19 quarantine management system and response plan into on-site management and social management. Through the AHP/IPA analysis, it was found that among social management, 'infectious disease management system and cooperation system with related institutions' and 'reduction of working hours' are areas with high importance but low satisfaction. After that, the causes of the two items were analyzed and related countermeasures were suggested. The results of this study will be able to contribute to the improvement of the quarantine management system and response plan at construction sites, and to minimize the damage to the construction industry related to COVID-19.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.227-239
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• 2023

Major depressive disorder is a leading cause of disability in more than 280 million people worldwide. Monoamine-based antidepressants are currently used to treat depression, but delays in treatment effects and lack of responses are major reasons for the need to develop faster and more efficient antidepressants. Studies show that ketamine (KET), a PCP analog, produces antidepressant effects within a few hours of administration that lasts up to a week. However, the use of KET has raised concerns about side effects, as well as the risk of abuse. 4 -F-PCP analog is a novel PCP analog that is also an NMDA receptor antagonist, structurally similar to KET, and might potentially elicit similar antidepressant effects, however, there has been no study on this subject yet. Herein, we investigate whether 4-F-PCP displays antidepressant effects and explored their potential therapeutic mechanisms. 4-F-PCP at 3 and 10 mg/kg doses showed antidepressant-like effects and repeated treatments maintained its effects. Furthermore, treatment with 4-F-PCP rescued the decreased expression of proteins most likely involved in depression and synaptic plasticity. Changes in the excitatory amino acid transporters (EAAT2, EAAT3, EAAT4) were also seen following drug treatment. Lastly, we assessed the possible side effects of 4-F-PCP after long-term treatment (up to 21 days). Results show that 4-F-PCP at 3 mg/kg dose did not alter the cognitive function of mice. Overall, current findings provide significant implications for future research not only with PCP analogs but also on the next generation of different types of antidepressants.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.75-82
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• 2023

The purpose of this study was designed to help the operation of the hospital organization through analysis of factors influencing organizational commitment of general hospital nurses. 129 nurses in general hospitals were targeted in G City. This study was conducted to analyze the effects of group efficacy, self-efficacy, and nursing professionals on organizational commitment. T-test, ANOVA, Pearson's correlation coefficient, Descriptive statistics and multiple regression were used. Stepwise regression analysis found that organizational commitment was affected by group efficacy(β=0.240, p =.003), nursing professionalism(β=0.229, p =.004) and daytime work(β=0.249, p =.003), The F statistic was 10.478 (p <.001). Therefore, in order to improve organizational commitment, it will be necessary to prepare communication programs and cooperation programs per unit to improve collective efficacy. In addition, it is necessary to improve the system, such as a system dedicated to night workers, so that the working hours of nurses in general hospitals can be maintained constant. In addition, it is necessary to develop a support program so that nursing professionals do not decrease due to disappointment in reality in the nursing field.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.103-114
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• 2023

Objectives: This study was conducted to evaluate hand-arm vibration (HAV) exposure levels due to the use of power hand tools and to evaluate the determinants in the automobile assembly process. Methods: The exposure level to HAV was evaluated for 30 work lines in five assembly processes (body, engine, chassis, door, and design) that use air-powered tools and battery-powered tools and operate in circulation for two hours. The 2-hr equivalent energy vibration acceleration, A (2), of the task was measured. The 8-hr equivalent energy vibration acceleration, A (8), was estimated in consideration of the number of tasks that can be performed per day by each process. In addition, a survey on the working environment was conducted with workers exposed to vibration. Results: The geometric mean of the HAV exposure level, A (2), for a total of 30 tasks was 2.51 m/s², and one case was 10.30 m/s², exceeding TLV (2hr). The HAV exposure level of A (8) was evaluated from 1.03 m/s² to 5.36 m/s². A (2) showed a statistically significant difference (P<0.01) for each process, and the chassis process (GM=3.90 m/s²) was the highest. The larger the tool size and the longer the tool length, the higher was the vibration acceleration when using a battery-powered tool than an air-powered tool (P<0.01). Battery-powered tool users showed higher dissatisfaction on all items than did air-powered tool users. Conclusions: As a result of this study, it is necessary to implement a program to reduce the HAV exposure levels.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.115-125
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• 2023

Objectives: This study was conducted to measure the level of radon in the air at a highway tunnel construction site in a gneiss area using the New Austrian Tunneling Method (NATM) and to evaluate exposure levels by occupation. Methods: Radon concentrations in the air were measured using E-PERM at points 300 m, 600 m, and 900 m from the tunnel entrance during the excavation and waterproofing work inside the tunnel. In addition, radon concentrations were measured during external excavation to compare with the inside of the tunnel. Personal exposure levels for major occupations including tunnel workers, construction equipment operators, waterproofers, shotcrete workers, and safety and health managers who participated in the construction were estimated using radon concentration measured in the work process area and working hours by occupation. Results: As a result of a total of 77 radon measurements, the geometric mean (GM) concentration was 71.1 Bq/m³, and the maximum concentration was 127.3 Bq/m³, which was below the indoor air quality criteria. Radon concentration by process decreased in the order of the tunnel excavation process (GM= Bq/m³, GSD=1.2), waterproofing process (GM=73.35 Bq/m³, GSD=1.2), and outside excavating process (GM=45.28 Bq/m³, GSD=1.2). Processes inside the tunnel were significantly higher than outside excavating processes (p<0.05). There was no statistically significant difference in radon concentration measured inside by distance from the tunnel entrance, but the innermost point of the tunnel, 900 m (GM=79.24 Bq/m³, GSD=1.27), measured the highest. Conclusions: The occupation with the highest individual exposure to radon was tunnel worker (64.16 Bq/m³), followed by construction equipment driver (64.04 Bq/m³) and waterproofer (63.13 Bq/m³).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.10-20
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• 2022

Objectives: The aim of this study is to evaluate exposure levels of the extremely low frequency magnetic fields(ELF-MF) radiated from various electric facilities in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the exposure levels of personal and local ELF-MF for the electronic facilities installed in two LCD manufacturing companies. Samplers were installed around workers' waist during working hours to identify personal exposure levels, and direct reading equipment were located at 3 cm, 10 cm, and 30 cm away from the surface of the electronic facilities to measure local exposure levels. Average and maximum(ceiling) values were calculated for personal and local exposure levels. Results: Average and maximum of personal exposure levels for each worker were 0.56(mean) ± 0.02(SE) µT and 6.31 ± 0.75 µT, respectively. Statistical analyses of the study found that maximum of the personal exposure levels for engineers was significantly higher than that for operators since engineers spend more time near the electronic facilities for repairing. The range of maximum personal exposure levels was 0.50 ~ 43.50 µT and its highest level was equivalent to 4.35 % of ACGIH(American Conference of Governmental Industrial Hygienists) exposure limit value(1 mT). Maximum of local exposure levels was 8.18 ± 0.52 µT and the electronic facilities with higher exposure levels were roof rail and electric panel, which were not related to direct manufacturing. The range of maximum local exposure levels was 0.60 ~ 287.20 µT and its highest level was equivalent to 28.7 % of the ACGIH exposure limit value. Lastly, the local exposure levels significantly decreased as the measurement distance from the electronic facilities increased. Conclusions: Maximum of personal and local exposure levels did not exceed the exposure limit value of ACGIH. However, it is recommended to keep the workers as far as possible from the sources of ELF-MF.