• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.3
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• pp.205-214
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• 2024

The aircraft delay rate has increased nearly three times in 2023 due to change in Korea policy of delay criteria. One of the primary causes of delays in domestic flights is related to reactionary delays, with Turnaround Time being a key factor. To mitigate reactionary delays and reduce aircraft delays, it is essential to establish an appropriate Turnaround Time and integrate it into flight schedules. This study aims to analyze the appropriate Turnaround Time for aircraft operating at Gimpo, Gimhae, and Jeju International Airports, which handle a high frequency of domestic flights. The research applies air traffic simulation, using variables such as current flight schedules, actual flight times, Turnaround Time, and flight routes to simulate actual conditions. Based on this analysis, the study seeks to identify the fitting Turnaround Time across various scenarios. The findings are expected to address reactionary delays and help reduce overall delay rates in domestic flights.

• International Journal of Molecular Medicine
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• v.43 no.6
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• pp.2499-2506
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• 2019

Photoaging is a consequence of chronic exposure to ultraviolet (UV) radiation and results in skin damage. In this study, whether tyndallizate of the probiotic bacterium Lactobacillus acidophilus IDCC 3302 (ACT 3302) can protect against UVB-induced photodamage to the skin was investigated. For this, HaCaT keratinocytes were used as a model for skin photoaging. HaCaT cells were treated with ACT 3302 prior to UVB exposure and skin hydration factors and matrix metalloproteinase (MMP)-1, MMP-2, and MMP-9 levels in the culture supernatant were evaluated by ELISA. The protective effects of ACT 3302 against UVB-induced oxidative stress in HaCaT cells was also assessed by measuring superoxide dismutase and catalase activity and detecting the expression of pro-inflammatory cytokine-encoding genes and mitogen-activated protein kinase (MAPK) signaling components by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. UVB exposure increased MMP expression and MAPK activation; these changes were attenuated by pretreatment with ACT 3302. Treatment with ACT 3302 prior to UVB exposure also attenuated inflammation. These results demonstrate that tyndallized ACT 3302 can mitigate photodamage to the skin induced by UVB radiation through the suppression of MMPs and could therefore be used clinically to prevent wrinkle formation.

• Journal of Environmental Science International
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• v.33 no.9
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• pp.675-685
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• 2024

This study aimed to analyze the effects of cesium (Cs) treatment concentrations and organic matter on the growth of Chinese cabbage plants. The growth responses of cabbage to the Cs treatment varied depending on the concentration of Cs and the organic matter content in the soil. Higher concentrations of Cs in the soil presented a detrimental effect on cabbage growth. Specifically, increased Cs levels led to a reduction in leaf number, leaf area, chlorophyll content, and fresh and dry weights. However, an increase in the soil organic matter content positively affected the fresh and dry weights. These trends were particularly pronounced in Chinese cabbage plants grown for 80 days after treatment. Soil organic matter proved to effectively mitigate the negative effects of Cs on plant growth. Incorporating organic matter into Cs-contaminated soils can, therefore, enhance the immobilization of radioactive isotopes and contribute to the stabilization of contaminated soils, making it a useful strategy for managing radioactive contamination.

• Journal of Korean Academy of Nursing
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• v.54 no.3
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• pp.329-339
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• 2024

Purpose: This study investigated the moderating role of general self-efficacy (GSE) on how stress caused by pregnancy and daily hassle affect the risk of preterm birth (PTB) in women experiencing preterm labor. Methods: This cross-sectional study included 196 pregnant women experiencing preterm labor before 37 weeks of gestation. We used IBM SPSS Statistics 27 and employed Hayes process macro version 4 (model 1) and hierarchical regression to analyze the moderating effect of GSE on the relationship between pregnancy stress, daily hassle stress, and PTB risk. Results: Stress caused by pregnancy and daily hassle was positively correlated to PTB risk (r = .54, p < .001; r = .25, p < .001, respectively). While GSE did not significantly correlate with pregnancy stress, it negatively correlated with daily hassle stress (r = - .19, p = .009). GSE significantly moderated the relationship between combined stressors and PTB risk. As GSE levels increased, escalation in PTB risk in response to increasing stress levels was a more pronounced, highlighting a complex interaction between higher GSE levels and response to escalating stress levels. This model accounted for 39.5% of the variance in the PTB risk. Conclusion: Higher GSE may amplify the impact of stress on PTB risk, rather than mitigate it, which suggests a more nuanced role of GSE in the stress response of pregnant women at risk of preterm labor. GSE should be considered in care strategies, and managing its impact on stress perception and responses in pregnant women is crucial.

• The Journal of Industrial Distribution & Business
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• v.15 no.9
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• pp.21-29
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• 2024

Purpose: This study aims to explore the relationship between exclusion experiences and tactile sensations in online contexts, moving beyond existing frameworks of social exclusion research. Social exclusion induces psychological and physiological pain similar to physical pain, which can lead to various behavioral responses aimed at overcoming these distressing experiences. This study focuses on the potential of touch to mitigate psychological and physiological pain. Individuals who experience social exclusion feel emotional distress, leading to an increased desire for physical contact, which is expected to influence their responses to positive tactile products. Data and methodology: To validate this, the study examines how individuals who have experienced social exclusion respond to tactile products, such as sweaters, in online environments. Results: The results indicate that participants in the exclusion condition had a higher purchase intention for tactile products compared to those in the control condition, confirming the psychological mechanism of the desire to touch these products. Conclusions: This research is the first to analyze the relationship between social exclusion and tactile products, contributing to the expansion of the field of social exclusion studies. Additionally, it provides practical implications for marketers regarding the exposure of products targeting individuals experiencing social isolation and emotional loneliness.

• Journal of Information Science Theory and Practice
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• v.12 no.3
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• pp.36-48
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• 2024

The information retrieval (IR) process often encounters a challenge known as query-document vocabulary mismatch, where user queries do not align with document content, impacting search effectiveness. Automatic query expansion (AQE) techniques aim to mitigate this issue by augmenting user queries with related terms or synonyms. Word embedding, particularly Word2Vec, has gained prominence for AQE due to its ability to represent words as real-number vectors. However, AQE methods typically expand individual query terms, potentially leading to query drift if not carefully selected. To address this, researchers propose utilizing median vectors derived from deep median networks to capture query similarity comprehensively. Integrating median vectors into candidate term generation and combining them with the BM25 probabilistic model and two IR strategies (EQE1 and V2Q) yields promising results, outperforming baseline methods in experimental settings.

• Journal of muscle and joint health
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• v.31 no.2
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• pp.95-106
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• 2024

Purpose: This study investigated how distress and stigma affect the quality of life (QOL) in stroke patients. Methods: A descriptive research design was utilized with 150 stroke patients from three general and three long-term care facilities. Data were collected through an 86-item questionnaire from February 15 to April 10, 2023, using measures of distress, stigma, and QOL. Analysis was conducted using descriptive statistics, independent t-tests, one-way ANOVA, Pearson's correlation coefficients, and hierarchical regression analysis in SPSS/WIN 25.0. Results: The average QOL score was 156.37±38.27 out of 245 points. Factors affecting QOL of stroke patients were distress (β=-.56, p<.001), stigma(β=-.26, p<.001), biplegia (β=-.11, p=.045), and unemployment (β=-.10, p=.045), explaining 68% of the QOL variance. Conclusion: Programs aimed at reducing distress and stigma in stroke patients are essential for enhancing QOL. Effective strategies should address post-stroke physical and mental states, prevent complications, restore health, reduce anxiety, and leverage family and social support to mitigate stigma. Special attention is needed for stroke patients with hemiplegia and those who are unemployed.

• Journal of Hydrogen and New Energy
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• v.35 no.4
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• pp.428-436
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• 2024

Liquid hydrogen, which operates in cryogenic environments has a density 800 times greater than gaseous hydrogen, making it advantageous for large-scale storage and transportation. However, continuous evaporation due to external heat intrusion and internal heat generation poses challenges. To mitigate heat conduction, various insulation materials are used. In pipe systems, viscous heating effects from turbulence and viscosity, especially in bends, cause heat generation. This study employs computational fluid dynamics (CFD) to analyze the impact of fluid velocity, pressure drop, inner diameter, and curvature radius of pipe bends on viscous heating. Using liquid nitrogen at 77 K as a working fluid, the CFD results showed that increased velocity and pressure drop along with smaller inner diameter and curvature radius enhanced viscous heating, raising fluid temperature.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.885-895
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• 2022

Since the supply and demand of agricultural products are unstable, which causes instability in farm income and consumer prices, the government has sought to mitigate the problems caused by unstable supply and demand by generating and providing agricultural outlook information. However, research should be carried out to increase the quality and utilization of agricultural observation information, because the value of agricultural observation information increases only when more users use this information and apply it to their decisions. In this study, a survey was conducted targeting producers and experts who are users or potential users of agricultural outlook information, and the results were analyzed through quantitative model, specifically importance-performance analysis (IPA) and analytic hierarchy process (AHP). The results show that improvement of promptness was required among the seven items evaluated with regard to agricultural outlook. Also, measures for dissemination of agricultural outlook information and the contents of outlook information should be improved to increase its use. If the quality level and use of agricultural observation information are increased by reflecting the results of the above analysis, decision-making on the supply and demand of agricultural products in Korea will be improved, and it is thought that it will be possible to increase farm household income and stabilize consumer prices through stabilization of supply and demand of agricultural products.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.2916-2922
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• 2024

\\In memory semiconductors such as a static random access memory (SRAM), a common problem is soft errors under radiation environment. These soft errors cause bit flips, which are referred to as single event upsets (SEUs). Some radiation-hardened SRAM cells such as a Quatro SRAM, we-Quatro SRAM, and DICE SRAM cells have been reported for years. However, these designs have the disadvantage of taking up more area than a conventional 6T SRAM cell. Thus, we propose a radiation-hardened SRAM cell design that we named capacitor-static random access memory (C-SRAM) without area overhead. The C-SRAM is formed by simply adding a capacitor to the conventional 6T SRAM. It was designed to mitigate the radiation effect using the conservation law of electrical charge. Moreover, it has the same cell size as the conventional 6T SRAM cell. Its static noise margins (SNMs), which are indicators of operational stability, are equal to the conventional 6T SRAM values of 530 mV, 220 mV, and 860 mV in hold, read, and write modes, respectively. The results of the SEU simulation test showed that it had 4.761 times better flipping tolerance than the conventional 6T SRAM with a charge value of 247.494 fC. In addition, irradiation experiments also confirmed that the C-SRAM cell was more tolerant than the 6T SRAM cell. The conventional 6T SRAM and C-SRAM were fabricated using a standard 0.18 ㎛ CMOS process.