In order to study the noise propagation characteristics and noise evaluation of military helicopters, this study conducted continuous noise monitoring of 20 noise-sensitive areas within 3 km around a military heliport in South Korea over a period of 5 days, and the results showed that the noise values at the 20 measurement points around the military heliport were lower than the limit of WECPNL 75 stipulated in the standard for civil airports, and it was found that the maximum noise level had the greatest influence on the evaluation indexes. The study found that the maximum noise level has the greatest influence on the evaluation index. At the same time, the analysis of the noise source spectrum shows that the helicopter noise is dominated by low and medium frequencies, and the low-frequency noise is more irritating in a short period of time.

Tire noise is one of major causes of vehicle noise, and urban traffic noise pollution is becoming more and more serious as the number of vehicles continues to increase. Especially in the age of electric vehicles, improvement of tire noise is getting more important. Especially during highway driving, the noise from the tire became the main noise source of the vehicle. Tire noise is generated from the mutual friction between the tire and the road surface when driving. In this paper, we analyze various factors affecting tire noise generation, reduce environmental noise pollution, and increase ride comfort. The EU carried out the EC 1222/2009 tire labeling system in 2012, which was a severe blow to the tire exporting countries of all countries due to the stringent demand for tire noise. In this paper, 5 tires from 3 countries were selected and selected as test subjects. The purpose of this study is to analyze the noise of road / tire noise according to road condition of each tire.

Exposure to extremely low frequency (ELF) electromagnetic fields (EMFs) from power transmission and distribution facilities has gained increasing attention with rising power demand driven by artificial intelligence (AI). This study proposes a practical EMF measurement method suitable for domestic power facility environments in Korea. Field measurements were conducted on 345 kV and 154 kV overhead transmission lines and 22.9 kV distribution lines based on ICNIRP guidelines and international standards IEC 62110 and IEEE Std 644. Measurements were performed at the maximum sag point at different lateral distances and representative heights. The results show that EMF levels were highest directly beneath the conductors and decreased rapidly with distance, while all measured values remained well below domestic exposure limits.

우리나라의 선박부문 대기오염물질 배출량 산정에 활용되는 배출계수는 유럽환경청의 가이드라인에서 제시하는 수치를 적용 하고 있다. 유럽환경청 가이드라인에서 제시하고 있는 수치는 2000년대 초에 발간된 문헌자료 기반의 배출계수로 선박부문의 다양한 규 제가 시행중인 현재의 배출상황과는 차이가 존재한다. 이에, 본 연구에서는 항만 입출항 선박현황을 조사하여, 여객선, 벌크선, 컨테이너 선, 탱커선 등 주요 선종을 대상으로 배기가스 실측 분석연구를 수행하였다. 배기가스 내 5종의 물질(CO2, CO, NOx, SOx, BC)을 대상으로 선박 운항형태별(운항모드,접안모드), 유종별(경유, 벙커유) 배출계수를 제시하였다. 실측기반의 배출계수를 활용하여 대기오염물질을 산 정하는 경우, 배출량 통계 정합성 확보에 기여할 수 있으며, 정확한 배출량 산출을 토대로 국가 대기환경개선 목표 달성에 이바지할 것으 로 기대된다.

This study aims to validate the feasibility of using LiDAR reflectivity data to quantitatively estimate the retroreflectivity of road lane markings. The goal is to establish the optimal scanning conditions considering the channel position, angle of incidence, and vehicle speed for an accurate and consistent retroreflectivity assessment in mobile environments. Fifteen standard lane marking samples with known retroreflectivity values were scanned using an OS1-128 LiDAR sensor under controlled field conditions. A two-phase experiment was conducted: (1) a speed-based test to assess the influence of vehicle velocity (20-80 km/h) on LiDAR reflectivity measurements, and (2) a channel–angle–distance test using a static testbed to analyze the relationship between retroreflectivity, LiDAR channel position (that is, the angle of incidence), and measurement distance. Ground truth retroreflectivity values were obtained using a high-precision handheld retroreflectometer. Reflectivity measurements showed a strong correlation with standard retroreflectivity values, particularly at scanning angle between 100-115° and distances of 4.9-5.6 m. The coefficient of determination (R2) exceeded 0.97 across optimal conditions. Speedrelated tests confirmed that the LiDAR-based reflectivity remained stable with a minimal RMSE (< 5), even under high-speed driving scenarios. LiDAR sensors provided reliable and contactless estimates of pavement marking retroreflectivity when the channel angle and scanning distance were appropriately selected. The findings demonstrated that channel-specific calibration and incidence angle correction significantly improved the measurement accuracy. This suggests a practical path forward for automated large-scale retroreflectivity monitoring in road asset management systems.

The results of the measurements using an optical surface roughness meter are shown according to the angle changes of 0, 0.5, 1, 1.5, 2, and 3°. Through the experiment, it can be seen that the measurement value is 3.140 at 0°, 3.148 at 0.5°, 3.140 at 1°, 3.151 at 1.5°, 5.078 at 2°, and 4.790 at 3° setting. In addition, the test statistic (P) value is 0.000, which is smaller than the significance level of 0.005, so it was confirmed through the experiment that a measurement error occurs according to the angle change when measuring the surface roughness.

Noise is defined as ‘unwanted sound’ or ‘undesired sound’. Recently, the aviation industry has been rapidly developing through convergence with cutting-edge technologies such as UAM. Accordingly, it is expected that new aviation industry models will continue to be created in Korea. In addition, it is expected that aircraft noise will be raised as a new social problem. The characteristic of aircraft noise is that it has a wide transmission range. Therefore, the area affected by aircraft noise is extensive, and the damage area varies depending on the flight path and flight environment. Additionally, it tends to occur continuously in certain areas. This study is an extension of the previous studies 􋺷Study on noise measurement and analysis of C172 aircraft at Muan Airport􋺸 and 􋺷Study on noise measurement and analysis of SR20􋺸, and investigated the noise characteristics of various piston engine trainer aircraft operated in Korea. We want to measure and analyze noise.

The main problem of airport noise is the impact of aircraft noise on the residents around the airport. In order to investigate the noise situation of a certain airport in South Korea, this article selects Muan Airport as the research project, selects five measurement points near the airport, takes aircraft takeoff as an example, measures the maximum noise level of each measurement point during each take off, and uses the American Airport Noise Prediction Software (AEDT 3C) to predict the noise of a single aircraft during take off, Calculate the contour area and sound exposure level data for four aircraft models. The results indicate that the average maximum noise level error between the measurement results and the simulation results is within 2dB, and the maximum noise level ranges from 65.1 to 88.1 decibels with the measurement range.

This study was conducted to verify the reliability of volatile organic compounds (VOCs) data derived from Selected Ion Flow Tube-Mass Spectrometers (SIFT-MS) measurements. In the previous study, the measurement reliability was validated using simultaneous measurements by SIFT-MS and gas chromatography-mass spectrometry (GS-MS), but in order to ensure more accuracy, and additional analysis was conducted by diluting standard gases (2 ppm) consisting of 10 types of VOCs mainly measured in industrial complexes (concentrations ranged from 0 to 500 ppb). As a result of 2 experiments, the SIFT-MS showed linearity and produced a coefficient of determination of over 0.99 for all cases. SIFT-MS has secured high measurement reliability, and it is considered to be able to efficiently manage VOCs emitted in industrial complexes.

In this study, data on indication errors within the range of 0 to 10 mm were measured using a dial gauge, which is widely used as a comparative measuring instrument in the field. Using Minitab, a statistical program, measurement conditions were determined during calibration of measuring instruments. Since the P value of the test statistic for the indication error is 0.000 to 0.003, the alternative hypothesis (H1) that no significant difference occurs due to a change in the measurement point at the significance level of 0.05 was adopted.

Painting pretreatment is an important task in determining the life of painting as it removes rust or foreign substances from the painting surface and gives adhesion between the painting surface and the painting surface. Since painting pretreatment is an important task, IMO strictly requires that the painting pretreatment surface be maintained at a Sa 2.5 grade and the surface roughness is 30μm~75μm. Painting pre-processing is an important task that determines the lifespan of a painting, but it is done through visual inspection by the inspector, and the quality varies depending on the inspector. In this study, in order to develop a quality measurement system for the painting pretreatment surface, Matlab2023b was used to determine the range of appropriate quality brightness by comparing the brightness of the painting pretreatment surface and surface roughness.

This study investigates the utilization of existing CCTV networks for road traffic volume measurement, a key indicator of road infrastructure utility. Traditionally, traffic studies, which are costly and time-consuming, are divided into continuous or ad-hoc surveys. By leveraging current CCTV systems, the proposed method eliminates the need for new installations, conserving resources and increasing efficiency. Preliminary results indicate that this approach offers a time and cost-effective alternative for traffic assessments, with the potential to transform traditional survey techniques.