• Structural Engineering and Mechanics
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• v.77 no.2
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• pp.197-215
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• 2021

Under a severe environment of multiple hazards such as earthquakes and winds, the life-cycle performance of engineering structures may inevitably be deteriorated due to the fatigue effect caused by long-term exposure to wind loads, which would further increase the structural vulnerability to earthquakes. This paper presents a framework for evaluating the lifetime structural seismic performance under the effect of wind-induced fatigue considering different sources of uncertainties. The seismic behavior of a high-rise steel-concrete composite frame with buckling-restrained braces (FBRB) during its service life is systematically investigated using the proposed approach. Recorded field data for the wind hazard of Fuzhou, Fujian Province of China from Jan. 1, 1980 to Mar. 31, 2019 is collected, based on which the distribution of wind velocity is constructed by the Gumbel model after comparisons. The OpenSees platform is employed to establish the numerical model of the FBRB and conduct subsequent numerical computations. Allowed for the uncertainties caused by the wind generation and structural modeling, the final annual fatigue damage takes the average of 50 groups of simulations. The lifetime structural performance assessments, including static pushover analyses, nonlinear dynamic time history analyses and fragility analyses, are conducted on the time-dependent finite element (FE) models which are modified in lines with the material deterioration models. The results indicate that the structural performance tends to degrade over time under the effect of fatigue, while the influencing degree of fatigue varies with the duration time of fatigue process and seismic intensity. The impact of wind-induced fatigue on structural responses and fragilities are explicitly quantified and discussed in details.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.221-227
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• 2021

Recently, interests in mask-type skin care devices using light-emitting diodes have been increasing and optical stimuli at certain wavelengths have been known to have various therapeutic effects, such as skin whitening, acne treatment, elasticity and wrinkle improvement by controlling the exposure to wavelengths of light and irradiation time. In particular, light sources of different wavelengths are applied in masks for the purpose of suppressing skin aging, inducing cell proliferation, and alleviating skin inflammation. In this paper, we developed a light-emitting diode control system that is actively used in skin regeneration masks using a microcontroller. Optical stimuli with different manners were applied to skin fibroblast cells in a single or complex wavelengths, and then confirmed how they are effective in the cell differentiation. In addition, we found a specific wavelength that has a positive effect on cell proliferation rates, and confirm the effectiveness of cell proliferation by image processing based quantitative analysis.

• Journal of Environmental Health Sciences
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• v.48 no.5
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• pp.255-265
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• 2022

Background: Research in environmental health (EH) is of crucial strategic importance for contemporary society. It is becoming even more critical in light of the increasingly rapid pace of environmental changes, opportunities, and threats. Objectives: This study aimed to identify trends and the prospective of environmental health research using SWOT analysis. Methods: The trends in environmental health research were reviewed in previous studies and reports. Reviewed manuscripts were searched for using the keywords of 'environmental health' and 'environmental hygiene' in the KCI (Korean Journal of Citation Index), KISS (Korean Academic Information), PubMed, and Google Scholar. Results: It is essential to center the EH research agenda around key priorities focusing on technological innovation, job creation, and the increasingly prominent role of the private sector. Given the rapidly evolving global sustainability agenda, greater clarity on the ever-increasing sources of complexity and growing expectations of the public might be needed. This requires the identification of criteria to identify EH research priorities with the ultimate goal of maximizing societal benefit. Public health relevance, such as extent and severity of health impact, level of exposure, and inequalities of effects, could be included. Conclusions: Considering the recent interest in and importance of environmental health, a comprehensive approach to environmental health research should be required through the application of the latest science and technology, citizen participation, and environmental health surveillance systems.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.351-374
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• 2022

The purposes of this study include i) to understand the circumstances of exposure to information during foreign refugees' stay in South Korea, ii) to investigate their information needs and the use of information sources, and iii) to propose the change needed in the Korean society, the role of South Korea in the global community, and the service direction of libraries and information professionals. To this end, legally recognized refugees who have stayed in South Korea were recruited for semi-structured in-depth interviews and observations on their perception, situation, and active behavior. The discussions were transcribed for coding. The codes were analyzed by content analysis technics based on relevant previous studies and factors of Dervin's Sense-making theory and Chatman's Information Poverty theory. Based on these analyses, this study proposed strategies for foreign refugees and individuals and public organizations, including libraries and NGOs, from an information service perspective. It is expected that the proposed strategies will supplement related empirical quantitative research and add value to information services for solving information problems.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.2
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• pp.75-86
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• 2022

This review aims to identify the influence of the vehicle and its concentration used to carry calcium hydroxide (Ca(OH)₂) medicament on postoperative pain. The protocol for this review was registered in the open science framework (Registration DOI-10.17605/OSF.IO/4Y8A9) and followed the guidelines provided by the Joanna Briggs Institute. Reporting was based on the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR). Literature screening and searches were performed on PubMed/Medline, Scopus, and EBSCO hosts. Furthermore, additional records were manually analyzed using various sources. The selected studies were published in English and included the use of any vehicle adjunct to Ca(OH)₂ to evaluate postoperative pain using qualitative and quantitative pain assessment tools. Descriptive analysis was conducted to review the study design, vehicle elements, and their effects. A preliminary search yielded 7584 studies, of which 10 were included. According to the data collected, the most commonly used Ca(OH)₂ vehicles were chlorhexidine (CHX), normal saline, and camphorated paramonochlorophenol/glycerine (CPMC/glycerine), which had a significant effect on postoperative pain. Among the included studies, six evaluated the effect of CHX as a vehicle. It was observed that a higher concentration of the vehicle (2%) showed a favorable response in reducing postoperative pain. A majority of studies have validated a positive consequence of using a vehicle on postoperative pain. Although higher vehicle concentrations were found to alter postoperative pain levels, the data were insufficient to draw a firm conclusion. Our scoping review indicates that further clinical studies should focus on using different vehicles at various concentrations and application times to check for feasible and safe exposure in addition to providing pain relief.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.21-36
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• 2022

BACKGROUND/OBJECTIVES: The long-term health impacts of dietary sugar have begun to be reported. The committee on the 2020 Dietary Reference Intakes for Koreans for sugar intended to update the scientific evidence on the association of added sugar intake with health outcomes, including mortality. This study evaluated the evidence on the association of dietary sugar with the all-cause and cardiovascular disease mortality from cohort studies. SUBJECTS/METHODS: The PubMed and ScienceDirect databases were searched until July 2021. The search terms were based on multiple combinations of keywords, such as added sugar, beverage, and mortality, included in the title or abstract. Two authors independently assessed the eligibility criteria of study selection and extracted the information from each selected article for this systematic review. RESULTS: The literature search identified 276 articles. Seventeen cohort studies met the inclusion criteria and were included in this systematic review. This study extracted information on the cohort and participants, dietary assessment methods, exposure and its comparison groups, health outcomes, and risk measures. Five articles reported added sugar intake, and 15 articles reported the food sources of the added sugar in the association with mortality. Increased mortality was observed in higher added sugar intake and a lower intake of less than 5% of energy, while higher discrepancies between gender, age groups, and countries were noted. In addition, nutritious sugary foods and beverages did not increase mortality. CONCLUSIONS: A 'U' or 'J' shaped relationship between the added sugar intake and mortality was estimated. The observed discrepancy indicated the need for more evidence to establish the dose-response relationship for Koreans.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.68-76
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• 2023

Background: In the process of discussion on the possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, a strategy for the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. Materials and Methods: The radiological protection criteria that are likely to be applied to the source-related approach based on the International Commission on Radiological Protection recommendations and the International Atomic Energy Agency safety standards are summarized. We proposed five interpretations of radiation protection to contribute to the promotion of discussion on the possibility of using a part of low-level-radionuclide-contaminated soil and debris in the post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in the post-accident rehabilitation when the sources are handled in a planned activity." The former idea is subdivided into three based on the definition of the source, which is managed by the reference level, and the latter idea is divided into two depending on whether or not additional dose from using contaminated materials is deemed acceptable. Results and Discussion: To confirm the applicability of the five interpretations presented, we suggested the concrete values of protection criteria via two feasible cases. In this case study, we proposed radiation protection by the dose constraint based on the Interpretation IV and chose 1 mSv/yr for the public and 20 mSv/yr for workers dealing with radionuclide-contaminated materials. Conclusion: We concretely and systematically demonstrated how the concept of radiation protection can be applied to the process of discussion on the possibility of using radionuclide-contaminated materials within the framework of an international system of protection. This study's findings can provide necessary information to discuss the possibility of using radionuclide-contaminated materials as an alternative option for recovery and reconstruction after a radiation disaster from the viewpoint of radiation protection.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.419-426
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• 2023

Objectives: This study aims to develop an Occupational Safety and Health (OSH) guide for the safe cleaning of contaminated machinery, equipment, and parts used in the electronics manufacturing process. Methods: A literature review, field investigations, and discussions were conducted. An initial draft of an OSH guide was developed and reviewed by experts with significant experience in maintenance work in the electronics manufacturing process in order to refine the guide. Results: Workers involved in cleaning processes with chemicals, solvents, and abrasive blasting can face exposure to a wide range of chemicals, abrasives, and noise. Identifying potential risks associated with each cleaning technique was an essential first step toward enhancing safety measures. The OSH guide comprises approximately eleven to twelve sections spanning 20-25 pages. It includes engineering and administrative protocols systematically organized to address the necessary actions before, during, and after cleaning tasks, depending on the technique. It is recommended that airline respirator masks be used in conjunction with an air purification system to ensure adherence to air quality standard "D" for atmosphere level. The use of an oil-free air compressor is advised, preferably a stationary model that does not rely on fuel sources like diesel. Conclusions: This OSH guide is designed to protect workers involved in maintenance activity in the electronics industry and aligns with global standards, such as those from the International Organization for Standardization (ISO) and Semiconductor Equipment and Material International, ensuring a higher level of safety and compliance.

• Child Health Nursing Research
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• v.30 no.2
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• pp.87-96
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• 2024

Purpose: The rising prevalence of smartphone overdependence among adolescents and its detrimental impact on mental health have become a growing concern. This study aimed to investigate the association between smartphone overdependence and the mental health of Korean adolescents. Methods: Participants were drawn from the 16th Korea Youth Risk Behavior Web-based Survey conducted in 2020. The dependent variable as smartphone overdependence, while the main exposure of interest was mental health, encompassing generalized anxiety disorder (GAD), perceived stress, sources of perceived stress, perceived loneliness, and perceived depressive symptoms. The study employed the Rao-Scott chi-square test and multiple logistic regression using IBM SPSS version 26.0. Results: The participants comprised 54,948 adolescents aged 13 to 18 years. Among them, 25.1% (n=13,775) were categorized as smartphone overdependence group. Specifically, 20.3% of adolescents who reported GAD ≥10 and 22.5% of those who reported experiencing high levels of perceived loneliness were identified as smartphone overdependent. The GAD increased a risk of smartphone overdependence by 2.61 times (95% confidence interval [95% CI]: 2.46-2.77). Perceived loneliness was associated with 1.98-fold (95% CI: 1.87-2.09) increased risk of smartphone overdependence. Additionally, conflict with peers was found to increase the risk of smartphone overdependence by 4.63-fold (95% CI: 3.89-5.52), followed by conflict with parents (odds ratio [OR]: 4.52, 95% CI: 3.84-5.31), and family environment (OR: 4.52, 95% CI: 3.75-5.46). Conclusion: The findings underscore a significant association between smartphone overdependence and mental health in Korean adolescents. Healthcare services to improve their emotional coping and interpersonal skills are necessary.

• Journal of Preventive Medicine and Public Health
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• v.57 no.2
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• pp.108-119
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• 2024

Objectives: Abrupt changes in air pollution levels associated with the coronavirus disease 2019 (COVID-19) outbreak present a unique opportunity to evaluate the effects of air pollution on influenza risk, at a time when emission sources were less active and personal hygiene practices were more rigorous. Methods: This time-series study examined the relationship between influenza cases (n=22 874) and air pollutant concentrations from 2018 to 2021, comparing the timeframes before and during the COVID-19 pandemic in and around Thailand's Khon Kaen province. Poisson generalized additive modeling was employed to estimate the relative risk of hospitalization for influenza associated with air pollutant levels. Results: Before the COVID-19 outbreak, both the average daily number of influenza hospitalizations and particulate matter with an aerodynamic diameter of 2.5 ㎛ or less (PM_2.5) concentration exceeded those later observed during the pandemic (p<0.001). In single-pollutant models, a 10 ㎍/m³ increase in PM_2.5 before COVID-19 was significantly associated with increased influenza risk upon exposure to cumulative-day lags, specifically lags 0-5 and 0-6 (p<0.01). After adjustment for co-pollutants, PM_2.5 demonstrated the strongest effects at lags 0 and 4, with elevated risk found across all cumulative-day lags (0-1, 0-2, 0-3, 0-4, 0-5, and 0-6) and significantly greater risk in the winter and summer at lag 0-5 (p<0.01). However, the PM_2.5 level was not significantly associated with influenza risk during the COVID-19 outbreak. Conclusions: Lockdown measures implemented during the COVID-19 pandemic could mitigate the risk of PM_2.5-induced influenza. Effective regulatory actions in the context of COVID-19 may decrease PM_2.5 emissions and improve hygiene practices, thereby reducing influenza hospitalizations.