This mixed-methods study investigated language anxiety among Korean military air traffic controllers (ATCOs) when communicating with native English-speaking pilots. The quantitative phase (N = 81) used hierarchical regression analysis examining relationships between individual characteristics and anxiety levels. The qualitative phase (N = 13) employed semi-structured interviews exploring controllers' experiences, anxiety triggers, and coping mechanisms. Results revealed that general communication anxiety (β = .69, p < .001) and English proficiency (β = -.28, p < .05) significantly predicted anxiety with American pilots, with psychological factors explaining 58.8% of variance. These findings suggest that language anxiety stems from broader communication apprehension rather than isolated linguistic difficulties. Qualitative analysis identified five themes: communication breakdown, technical factors, skills hierarchy, informal coping, and institutional gaps. Overall, the study indicates that language anxiety in military ATC contexts is complex, influenced by individual psychological traits, situational demands, and organizational factors. It contributes to a deeper understanding of professional language anxiety in safety-critical contexts and provides evidence-based recommendations for aviation English training reform.

This study analyzed policy measures to comprehensively achieve two goals: carbon neutrality in buildings and optimization of indoor air quality. While buildings account for approximately 40% of total energy consumption and greenhouse gas emissions, and present-day individuals spend 90% of their daily lives indoors, both goals are critically important. However, these objectives often conflict with each other, and current policies have limitations in effectively addressing this complex relationship. Analysis of related policies, including the Green Building Creation Support Act and the Indoor Air Quality Management Act, revealed significant drawbacks such as the lack of an integrated approach due to policy fragmentation, insufficient consideration of lifecycle carbon emissions, imbalance in economic incentive structures, and rigidity in technical standards. To overcome these challenges, this study proposes innovative improvement measures, including the following: establishing an integrated policy framework, introducing a multi-layered air quality management system, expanding performance-based design that simultaneously considers energy efficiency and indoor air quality, developing region-specific policies, implementing AI-based self-assessment systems, mandating green space ratios, controlling high-radon concentration areas, and expanding government incentives.

This study analyzed the emission characteristics of major air pollutants from 97 domestic municipal solid waste incineration facilities using tele-monitoring system (TMS) data collected from 2015 to 2023. Focusing on the effects of the enforcement of enhanced national emission standards in 2019, this research examined changes in emission factors (EFs) of dust and nitrogen oxides (NOX) by facility capacity and aging level. The results showed that the average EFs for dust and NOX significantly decreased by up to 30% after enforcement (p<0.01~0.001), indicating the practical effectiveness of the strengthened standard. This trend was observed consistently across all facility sizes and aging levels, including large-scale and older facilities. In contrast, hydrogen chloride (HCl) and carbon monoxide (CO) did not show clear reductions and remained highly variable, suggesting that emission standards alone may not be sufficient for stable control. These findings demonstrate the need for optimized combustion conditions and improved post-treatment systems for pollutants such as HCl and CO. This study provides empirical evidence highlighting the importance of appropriate facility scale and systematic refurbishment cycles for stable emission reduction in municipal waste incinerators.

The COVID-19 pandemic has caused significant disruptions in global air travel demand, presenting new challenges for accurately forecasting passenger volumes. This study analyzes the monthly air passenger demand data from 2010 to 2022 to identify key external factors that influence passenger demand. Our analysis shows that the number of international visitors to Singapore is a critical determinant of passenger demand. Consequently, we propose a SARIMAX (Seasonal AutoRegressive Integrated Moving Average with eXogenous variables) model to forecast monthly air passenger demand at Singapore's Changi Airport, integrating international visitor numbers as an exogenous variable. Through comprehensive model identification and parameter estimation, we select the best SARIMAX configuration. To validate the performance of the model, traditional time series methods such as SARIMA, various exponential smoothing methods, and advanced machine learning methods like LSTM (Long Short-Term Memory) and Prophet were compared for forecasting monthly air passenger demand at Changi Airport in 2023. The results show that the SARIMAX model significantly outperforms all other tested models, achieving the best performance across multiple forecasting metrics, including the Mean Absolute Percentage Error.

This study analyzed the emission characteristics of major air pollutants (dust, nitrogen oxides, hydrogen chloride, and carbon monoxide) emitted from domestic public waste incineration facilities based on their operating elements. Using automatic measuring equipment for smokestacks (TMS), data was collected from 97 facilities from 2015 to 2023. The emission source unit (kg/ton) was evaluated based on the facility’s capacity, aging level, and incineration type. Emissions were calculated, and descriptive statistical analysis was performed based on the mean, standard deviation, and coefficient of variation. As a result of the analysis, it was found that the larger the facility capacity, the lower the average emission and volatility, which suggests that the operational stability of large facilities is high. On the other hand, facilities that had deteriorated for 10 to 15 years had the highest emission rates, and emissions decreased in facilities that were aged more than 20 years. In addition, the pyrolysis and high-temperature melting incineration facilities had lower NOx and HCl emissions than the conventional incineration type. Furthermore, CO showed the greatest volatility overall, which was found to be particularly difficult to manage in facilities in the early to mid stages of aging. These results provide empirical evidence that the structural characteristics and incineration type of incineration facilities have a significant impact on air pollutant emissions and can serve as useful basic data for policy-making, including for implementing region-wide initiatives and planning major repairs in the future.

This study examined the influence of multiple factors—particularly occupant presence and air purifier operation—on indoor PM2.5 concentrations across 104 households in the Seoul metropolitan area. Both indoor and outdoor PM2.5 concentrations were continuously monitored and integrated with time-specific survey data to analyze spatial and temporal patterns of indoor exposure. Results showed that occupant presence significantly elevated indoor PM2.5 concentrations, especially during periods of high activity (08:00~15:00 and 18:00~20:00). The indoor/outdoor (I/ O) concentration ratio was also significantly higher during these periods, indicating that occupant activities were a major contributor to indoor PM2.5 concentrations. Air purifier use was found to be associated with a consistent reduction in indoor PM2.5 concentrations, regardless of occupancy status. Notably, the I/O ratio also decreased when air purifiers were in operation, demonstrating their effectiveness in controlling both indoor emissions and the infiltration of outdoor pollutants. These findings provide empirical evidence of the multifactorial dynamics governing indoor PM2.5 exposure and highlight the importance of occupant-centered and time-specific strategies for effective residential air quality management.

This study aims to enable early detection of low-concentration airborne respiratory viruses in multi-use facilities using a cyclone-based air sampler (Coriolis® m , Bertin). To achieve this, bacteriophage MS2 of Escherichia coli was aerosolized into a chamber at varying concentrations, reflecting levels observed in indoor environments. The rationale for differentiating viral concentrations was to assess field applicability and optimize sampling conditions. Sampling efficiency was maximized by adjusting sampling time, flow rate, and media volume to determine optimal detection parameters. The effectiveness of the optimized conditions was further validated through cross-validation using Influenza A and field testing. Field experiments conducted on 10 samples across five locations confirmed airborne virus detection in one of the samples (10%), demonstrating the feasibility of the cyclone-based air sampler method for airborne virus collection and detection.

Considering the intrinsic activity of non-precious metal oxygen reduction reaction (ORR) catalysts is typically lower than that of precious metal catalysts, it is crucial to focus on the rational design of their micro-morphology and active site. This paper employed a simple molten salt-mediated template method to fabricate a Fe3C composite N-doped C catalyst with a layered porous framework ( Fe3C@NC). Tannic acid was utilized to form a strong coordination with iron to limit the grain size of Fe3C nanocrystals generated by high-temperature pyrolysis. Moreover, urea achieved nitrogen doping in tannic acidderived porous carbon, while the graphite phase nitrogen-doped carbon (g-C3N4) formed by its pyrolysis, together with the molten salt-mediated environment, jointly controlled the two-dimensional sheet-like structure of the material. The optimized Fe3C@ NC-800 demonstrated efficient ORR performance, with an ORR half-wave potential of 0.883 V. Its application as a cathode catalyst in a liquid zinc-air battery (ZABs) exhibits a maximum power density of 211.5 mW cm− 2, surpassing that of a Pt/C-based ZAB and indicating the potential practical utility of this material.