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.

This study investigates hybrid propulsion for UAM & AAM as demand shifts toward short-range urban and suburban mobility enabled by advances in lightweight aircraft technologies. Urban low-altitude operations with frequent takeoffs and landings under stricter noise regulations require both high propulsion efficiency and low acoustic emissions. While electric propulsion provides precise controllability and low vibration, limitations in battery energy density and charging infrastructure constrain range, endurance, and turnaround. Hybrid propulsion can mitigate these constraints by combining the high energy density of fuel with the motor’s low-noise, fast-response operation. Accordingly, this study quantitatively compares thrust performance and noise spectra of an identical propeller when driven by an electric motor versus an internal combustion engine, providing baseline evidence to support hybrid propulsion system design.

소음성난청은 장기간의 소음 노출에 의해 누적적으로 진행되며, 일단 발병하면 회복이 어렵다는 특성이 있으므로 예방적 관리가 무엇보다 중요하다. 이러한 근로자 건강장해 예방을 위해 청력보존프로그램(Hearing Conservation Program)은 사업주가 수립하고 운영 해야 할 종합적인 관리 계획이며, 정부의 산업안전보건 정책에서도 청력보존프로그램의 수립 대상을 청력손실 가능성이 있는 모든 작업으로 확대하는 등 그 중요성이 지속적으로 강조되고 있다. 본 연구는 소음성난청 예방을 위한 청력보존프로그램의 실효성 확보를 위한 개선 방안을 제시하는 것을 목적으로 수행하였다. 이를 위해 학술 논문, 산재승인 현황, 작업환경측정 결과 등 사례 중심의 조사와 청력보존프로그램의 운영실태는 FGI 면담을 통해 분석하였다. 그 결과, 소음수준이 높은 사업장일수록 특수건강진단 결과에서 C1, D1 판정자의 분포가 높게 나타나 소음성난청 발생 위험이 있으며 현재 시행중인 청력 보존프로그램은 보호구 착용, 정기 건강진단에 치우쳐 있어 소음관리와 청력보존프로그 램의 실효성 확보는 시급한 과제임이 확인되었다. 이를 위해, 경영진의 정책적 지원, 근로 자의 참여, 관리감독자의 지속적인 관심을 포함한 종합적 운영이 필수적으로 프로그램의 각 단일요소의 실행이 아닌 “유해인자 확인(식별)→노출(위험)의 평가→조치(공학･관리 대책)→검토 후 피드백으로 구성된 PDCA 기반 통합순환 체계를 상호보완적으로 적용할 필요가 있다. 본 연구에서 제시한 실효성 확보방안은 근로자 청력 보호를 위한 정책적･실 천적 기초자료로 활용될 수 있을 것이며, 또한 기업의 ESG 경영요소 중 하나인 기업활동 의 리스크 관리와 책임경영에 도음이 될 것으로 기대된다. 향후 연구에서는 실제 산업현장 에 적용하여 효과를 비교･검증하고, 소음 수준별 맞춤형 대책을 구체적으로 제시하는 등 개선효과를 실증적으로 검증할 필요가 있다.

도로변 투명 방음벽은 소음 저감 효과뿐만 아니라 경관 개선이라는 관점에서 널리 설치되고 있으나, 높은 반사율과 투명도로 인해 야생조류 충돌의 주요 원인으로 지목되고 있다. 본 연구는 경상남도 전역을 대상으로 조류 충돌 현황을 파악하고, 충돌 위험지역의 공간적 특성을 규명하여 투명 방음벽의 조류충돌 저감 대책 수립을 위한 기초 자료로 제공하고자 수행되었다. 2000년부터 2023년까지 현장 조사, 비영리 단체 자원봉사, 시민과학 자료를 통해 총 3,638건(74 종 3,686개체)의 충돌 정보를 수집하였다. 분석 결과 멧비둘기, 물까치, 직박구리 등 텃새가 주요 충돌 종으로 나타났으며, 계절별로는 겨울철이 가장 많았다. 방음벽 주변 토지피복은 충돌 여부와 무관하게 80m 이내 구간에서 시가화 건조지역과 초지 비율이 급격히 증가하는 경향을 보였다. 종분포 모델(MaxEnt) 분석 결과, 다양한 요인 중 산림과의 거리가 가장 큰 연관성을 보였으며, 산림-농업, 산림-도시 등 생태계 경계부의 저지대에서 충돌 위험이 집중되는 것으로 나타났다 (AUC=0.921). 이 결과는 투명 방음벽의 충돌 위험이 방음벽의 구조적 특징뿐만 아니라 주변 공간구조와 지형적 특성과 밀접하게 연관됨을 시사한다. 따라서 신규 방음벽 설치 시 방음벽의 조류충돌 저감 설계 반영과 함께, 시민과학 참여를 통한 지속적 모니터링 등을 통한 위험지역 도출과 고위험지역에 대한 우선 저감 조치가 필요하다.

Priority should be considered to encourage businesses to participate by activating the low-noise machine certification system. However, the domestic low-noise machine certification system has not yet been significantly activated. There is a need for a system that only products that meet the environmental sign certification standards for low-noise construction machinery are recognized as "low-noise machines". A compliance evaluation agency (CAB) in the field of low-noise equipment should be introduced in Korea to help facilitate international certification of domestic company products. Therefore, it is believed that it will help expand the supply of low-noise machines through technology development and export improvement.

In recent years, airport construction projects have been promoted in island regions such as Gadeokdo, Baengnyeongdo, Ulleungdo, and Heuksando. However, a systematic review of the potential impact of aircraft noise transmitted underwater on marine life remains insufficient. This study acoustically analyzes the transmission process of airborne noise generated by aircraft as it passes through the sea surface and enters the underwater environment. The physical mechanisms are examined with a focus on transmission loss, conditions for total internal reflection, and acoustic impedance differences. In particular, the theoretical transmission coefficients of sound pressure and particle velocity at the air–water interface are reviewed and compared to the auditory reception ranges of marine organisms to assess the potential for acoustic impact. The findings of this study can serve as foundational data for establishing coastal and island airport noise management standards and formulating marine ecosystem protection policies.

This study quantitatively analyzed Buzz, Squeak, and Rattle (BSR) noises occurring during automotive operation and identified their root causes. Abnormal noises were initially detected during a first test drive and were classified into BSR types based on data from a Noise Observer system. Case analysis revealed that in the 2020 G model, a squeak noise was caused by friction between solid components due to durability degradation and damage to the suspension bushing. In contrast, the 2022 G model exhibited a rattle noise resulting from insufficient structural gaps. As modern vehicles continue to pursue higher performance, safety, and cabin quietness, the reduction in component gaps has increased the likelihood of BSR occurrences. This study demonstrates the effectiveness of diagnosing the root causes of BSR and confirms its practical value in reducing maintenance time and minimizing misdiagnoses.

This study investigated the operation status of major construction machines used in domestic construction sites and analyzed the characteristics of noise generated by these machines. In addition, we tried to understand the impact of construction machine noise on the working environment and the surrounding environment. As a result of the analysis, the noise level of the working breaker was the highest at 101.5 dB(A). This suggests that it can act as a major factor in the spread of noise to the residence around the construction site and the occurrence of civil complaints from residents. Therefore, this study is expected to provide a scientific basis for the noise problem of construction machinery and be used as basic data for effective noise management policies and system improvement.

This study examines the impact of Propeller blade pitch angle mismatch on Noise, thrust, and vibration in light aircraft. Tests were conducted using a simulator with one blade set at increased pitch angles (10°, 12°, 14°) compared to the standard 8°. Results showed that mismatches increased vibration (above 0.26 IPS), Noise levels, and caused operational issues such as fuel leakage and backfire. While thrust initially increased with pitch, it dropped at 14° due to fuel flow instability. These results highlight the need for strict pitch alignment tolerances to ensure optimal performance and safety in aircraft maintenance and operation.