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.

본 연구는 수직농장에서 상업적 생산에 적합한 왜성 토마토 를 대상으로 음이온을 처리하고, 생육단계별(영양생장, 생식 생장) 생육 특성과 기체교환 활성 반응을 분석하여, 과채류에 대한 음이온의 적용 가능성을 평가하고자 수행되었다. 실험 을 위해 왜성 토마토 묘를 온도 24도, 습도60%, 이산화탄소 농도 600μmol·mol-1, 광도 320μmol·m-2·s-1 PPFD, white LED, 광주기16h의 수직농장 모듈에서 5주간 재배하였다. 음 이온은 광주기 시간동안 12 × 105ions∙cm-3의 음이온을 처리 하였다. 정식 후 5주 동안 매주 생육조사를 진행하였고, 정식 후 4주 동안 매주 광합성율과 증산율을 측정하였다. 정식 1주 차 광합성율은 음이온 처리구에서 유의적으로 높게 나타났으 나, 이후에는 광합성율과 증산율 모두 처리구간 유의 차이는 확인되지 않았으나, 전반적으로 음이온 처리구가 대조구보다 높은 수치를 나타내는 경향을 보였다. 영양생장 지표들은 처 리간 차이가 크지 않았으나, 생식 기관의 발달(화방수, 꽃수, 과실수)은 대조구에 비해 유의적으로 높은 값을 나타냈다. 이 러한 결과는 음이온 처리가 과채류인 왜성 토마토의 생식생장 을 촉진하고 과실 생산량을 증가시켰음을 확인하여, 과채류 에 음이온의 적용 가능성을 확인하였다. 향후에는 음이온 처 리 농도의 최적화 및 수확한 과실의 품질 비교를 포함한 후속 연구가 필요하다.

This experiment was carried out to study the effect of elapsed time after air flow cutoff on the germination rate of Italian ryegrass seed with different moisture contents during natural drying on reclaimed land, Jangheung and Kimje of Korea from 2023 to 2024, respectively. Seeds with moisture contents of 15.3, 22.3 and 28.0% were placed in vinyl bag (30 × 40 cm) at storage thicknesses of 10, 15, and 20 cm, and air flow was cutoff for 48 h. Seed moisture content, seed temperature (℃) and germination rate were investigated at 12-h intervals. After 48 h of airflow cutoff during natural drying, seed moisture content did not significantly differ among storage thickness treatment (p>0.05). When Italian ryegrass seeds with moisture contents of 27~28% were stored under conditions with air flow cutoff at 15~20cm thickness for 48 h, the seed temperature reached up to 30℃ and the germination rate was excellent at around 70~80%.

이 연구는 다목적 선박(MPV)의 공기역학적 구조물 설계, 분석 및 향상을 통해 그린 워터 압력에 의한 구조적 안전을 보장하고, 탈탄소화 및 에너지 효율성에 이바지하는 방법을 기술하였다. 유한 요소 분석(FEA)을 통한 초기 평가에서 좌굴 발생에 대한 잠재적인 취약점 이 있음을 확인하였다. 이러한 문제를 해결하기 위해 보강재(Carling stiffener)와 두께 증가를 통하여 응력을 재분배하고 국부적인 좌굴 발생의 위험을 최소화하였다. 보강 후 분석 결과, 한국선급(KR)의 안전 기준인 항복 강도, 미국 선급(ABS) 좌굴 강도 및 노르웨이 표준(NORSOK) 변 위 기준을 모두 충족하는 것이 확인되었다. 결과적으로 고유치 좌굴 해석 결과가 안전 기준을 초과하고 최대 변위가 허용 한계 내에 있는 등 중요한 개선이 이루어졌다. 이러한 개선은 극한의 해양 조건에서 운영 신뢰성을 보장할 수 있다. 이 연구는 공기역학적 항력 감소와 구조적 안전성의 이중적인 이점을 강조하며, 국제 해사 기구(IMO)의 2050 탈탄소화 목표에 부합하는 연료 효율성 및 온실가스 배출 감소에 이바지할 수 있다. 연구 결과는 다양한 선박 유형에 걸쳐 항력 감소 기술을 확장하기 위한 기초 자료를 제공하며, 지속 가능하고 탄력적인 해양 운영을 위한 대안을 제시하였다. 향후 연구는 구조적 안전 평가를 가속할 수 있는 단순화된 모델링 기술 개발에 집중할 것이다.

This study proposes a mathematical model to optimize the fighter aircraft-weapon combinations for the ROKAF(Republic Of Korea Air Force). With the recent emergence of the population declining issue in Republic of Korea, there is an urgent need for efficient weapon system operations in light of decreasing military personnel. In order to solve these issues, we consider to reduce the workload of pilots and maintenance personnel by operating an optimal number of weapons instead of deploying all possible armaments for each aircraft type. To achieve this, various factors for optimizing the fighter-weapon combinations were identified and quantified. A model was then constructed using goal programming, with the objective functions based on the compatibility, CEP(Circular Error Probable), and fire range of the weapons, along with the planned wartime mission-specific weapon ratios for each aircraft type. The experimental result's analysis of the proposed model indicate a significant increase in mission performance efficiency compared to the existing system in both operational and maintenance aspects. We hope that our model will be reflected to help improve the operational capabilities of Republic of Korea Air Force.

This study analyzed IoT-based indoor air quality monitoring data in a cooking room at a high school in Seoul. As a result of measuring the type and concentration change of cooking fumes generated during roasting, frying, and stir-fry, each cooking method showed a different pattern. Some cooking fumes were observed high during the distribution process, not during cooking, and it is necessary to observe and control indoor air quality during the entire process of cooking, storage, and distribution as well as various elements of cooking fumes. Through these results, we propose the addition of an IoT-based real-time indoor air quality monitoring system and ventilation facilities linked to it.

The importance of indoor air quality has significantly increased after the COVID-19 pandemic. This study analyzed the energy consumption of a ventilation system based on various operating methods considering indoor and outdoor conditions. From March to May 2024, experiments were conducted on ventilation systems installed in a hospital in Incheon, comparing the experimental and control groups. The results showed that using the bypass mode in the experimental group reduced total energy consumption by 25.34% compared to the control group. Additionally, utilizing the air-cleaner mode further reduced energy use. This study demonstrates that optimal use of bypass and air-cleaner modes can enhance energy efficiency. Further research is needed to verify long-term applicability under diverse conditions.

본 연구는 우리나라 연근해 선박의 친환경 기술 도입이 대기오염물질 저감에 미치는 효과를 분석하고, 이를 통해 향후 정 책 방향을 제안하기 위해 수행되었다. 최근 국제해사기구(IMO)와 정부·기관들은 해양 대기오염 문제를 해결하고 탄소중립 목표를 달 성하기 위해 다양한 친환경 기술의 적용을 촉구하고 있으며, 특히 연근해 운항 선박에서 발생하는 질소산화물(NOx), 황산화물(SOx), 미세먼지(PM)와 같은 주요 오염물질의 저감이 시급한 상황이다. 다양한 대체연료(LNG, 메탄올, 배터리 등)와 후처리기술(DPF)을 시나 리오별로 적용하고, 각 시나리오에서 대기오염물질(PM10, PM2.5)의 배출 감축량을 예측하였다. 분석 결과, 2030년까지는 DPF와 바이오 연료와 같은 즉각 적용 가능한 기술들이 효과적인 저감 수단으로 나타났으며, 2050년까지는 무탄소 연료와 전기 추진 기술의 상용화 가 필수적임을 확인하였다. 친환경 기술 도입이 대기오염물질 배출량에 미치는 영향을 정량적으로 제시함으로써, 해운 분야의 친환경, 탄소중립 달성을 위한 정책적, 기술적 인프라 확충의 필요성을 강조하고 있다. 이를 통해 정부의 지원 및 규제 필요성을 제안하고자 한다.