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.

NVH(Noise, Vibration, and Harshness) characteristics are critical indicators for evaluating automotive quality and diagnosing mechanical issues through abnormal vibrations during driving. Among various components, tires are the only part of the automotive in direct contact with the road, making them a major source of noise and vibration. Tire-related anomalies not only affect ride comfort but can also pose serious safety hazards. This study presents a diagnostic approach that utilizes NVH analysis, wheel balance inspection, and RFV(Radial Force Variation) measurement to identify and repair tire faults. Through case analysis, it was confirmed that abnormal vibrations caused by internal moisture accumulation and structural deformation of tires could be accurately diagnosed and addressed. The proposed method enables early detection of tire-related issues, providing a preventive maintenance strategy and contributing to enhanced automotive safety and reliability.

산업현장에서 소음이 작업자의 건강과 안전에 중대한 문제로 대두되고 있는 가운데, 특히 단속음은 간헐적이고 불규칙한 소음으로 반복적인 음압 변화를 유발하여, 청각뿐만 아니라 생리적·심리적 건강에도 악영향을 미치고 있다. 본 연구는 산업현장에서 자주 접하는 단속음 이 인간의 생리적 스트레스 반응에 어떠한 영향을 미치는지를 규명하고자 하였다. 실험은 무소음 상태를 기준으로 75 dB, 80 dB, 85 dB의 단속음 조건에서 수행되었으며, 뇌파 (Electoencephalography, 이하 EEG) 측정을 통해 스트레스 반응을 정량적으로 분석하였다. 주요 분석 지표는 RA(Relative Alpha), RAB(Relative Alpha to Beta), RHB(Relative High Beta)로 설정하였다. 실험 결과, 단속음의 강도가 높아질수록 RA는 0.42에서 0.16으로, RAB는 7.05에서 1.40으로 각각 약 62%, 80% 감소하였고, RHB는 0.13에서 0.17로 약 31% 증가하는 경향을 보였다. 이러한 결과는 고강도 단속음이 신경계 안정성을 저해하고 스트레스 반응을 유의미하게 증가시킴을 시사한다. 본 연구는 ESG 경영 차원에서 산업현장의 건강친화적 소음 관리의 중요성을 강조하며, 소음 저감 정책 수립의 과학적 근거를 제공한다.

Recently, automotive are used not only as a means of transportation, but also as a private and leisure spaces. In order to secure competitiveness in the automobile market, we must improve durability and noise/vibration technologies. The driver wants to keep quiet even if the car is used for a long time. The types of noise and vibration generated by the automotive can be divided into NVH and BSR. NVH should be reduced because it is caused by mechanical defects and aging. In this study, it was possible to accurately analyze the cause of noise and vibration, also it could identify the location, and repair that. In the future, research of an abnormal and vibrations such as NVH and BSR in automotive is needed to clearly identify.

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.

Reducing underwater radiated noise from a ship is a critical issue for ensuring the survivability of the vessel. As high-speed signal processing and interlocking algorithms become more sophisticated, the heat intensity of shipboard equipment is increasing per unit volume. When designing shipboard equipment, it is necessary to consider the trade-off between heat dissipation and noise reduction. Following an analysis of the trade-offs, it was determined that the arrangement of Fan Ass'y A and B exhibited excellent noise and heat dissipation characteristics. Based on this, PWM control operating zones were derived. It was determined that the placement of Fan Ass'y A and B in the operating zone would increase the PWM duty cycle from 33% to 58% using a signal frequency of 25kHz band with guaranteed reliability. This would increase the noise by approximately 9dB(A) but reduce the internal board reference temperature by up to 15℃.

In the case of a rear-wheel drive vehicle, a propeller shaft is installed to transmit the driving force of the engine. At this time, the propeller shaft is divided into 2 or 3 pipes, and the bearing is mounted on the vehicle body. And the end of the propeller shaft is connected to the rear differential and connected to the body through the chassis. Due to this complex structure, the propeller shaft must be highly balanced and the mounting angle must be well maintained. However, depending on the driving conditions of the car, various noise and vibration problems occur due to the aging of the parts and the propeller shaft. Hyundai Motor Company's maintenance center uses 'Noise Observer' to resolve various noise and vibration customer complaints. This paper describes the mechanism of vibration problems caused by unbalance of the propeller shaft and the diagnosis process using a 'Noise Observer'.

소음공해는 인간과 해양환경에 악영향을 끼치며, 선박과 해양구조물에서 발생하는 유동소음을 예측을 통해 소음에 대한 안전 성을 평가하고 해양환경을 보존할 수 있다. 기존 수중구조 유동소음 해석기법은 전산유체역학과 FW-H음향상사식을 이용한 하이브리드법 기반이다. FW-H는 무한공간에서의 음향전파를 가정하여 소음해석을 수행하기 때문에 음파의 반사와 산란, 회절의 영향이 나타나는 근접 장 해석이 제한적이다. 반면 격자볼츠만기법 기반의 직접법 유동소음해석을 수행하면 근접장 음향효과를 소음해석에 반영할 수 있다. 직 접법 해석은 유동과 소음이 연성된 해석이 수행되고 구조경계에서의 반사와 회절, 유동에 의한 매질 불균일성에 따른 산란효과가 반영된 다. 그간 격자볼츠만기법이 수중조건에서 수치적으로 불안정하여 수중환경에 적용이 불가능했다. 하지만 수중환경에서 사용할 수 있는 DM-TS 격자볼츠만기법 충돌연산자가 개발되어 수중으로 확장이 가능해졌다. 본 연구에서는 파이프내 원형구멍에 대하여 격자볼츠만기 법 해석을 수행해 수중 유동소음해석이 가능함을 보였다. 격자볼츠만기법 해석을 통해 도출한 유동과 소음을 각각 실험과 비교하여 해석 의 신뢰도를 확보하였다. 파이프내 유동소음에 의한 주요 압력 피크가 해석에 반영되었으며 이를 통해 격자볼츠만기법을 이용한 근접장 유동소음해석이 가능함을 확인했다.

Noise is a sound that people don't want. In this study, noise is measured for SR20, a general aviation trainer used in Korea. In addition, noise measurement points are selected at Muan Airport, where most of the domestic trainers fly under the supervision of the Ministry of Land, Infrastructure and Transport, and the measured data are analyzed based on this. We also want to analyze the noise characteristics of SR20 aircraft through frequency analysis of the noise characteristics of SR20 aircraft are unique. We want to use this to understand what type of noise the trainer affects in future studies. this study will improve the reliability of the noise prediction scenario by comparing and analyzing the actual measured and predicted values when using the noise prediction program.

Environmental noise occurring on ships has various negative impacts on sailors’ health conditions such as hearing loss, sleep disturbance, psychological stress, etc., so regulations on them are required, but the ship noise regulations are usually applied to only large merchant ships. Although regulations on fishing boats with strong fishing and work intensity are determined to be necessary, there has been little relevant research. This study, therefore, attempted to measure the environmental noise of coastal composite fishing vessels less than two tones and provide the results of basic research on the noise regulations for fishing vessels. It measured them by setting the measurement zones as after side, midship and fore side, and based on the criterion of IMO MSC 337(91). The findings showed that the noise of them often exceeded 75dB(A), the criterion of the open deck noise in the zones in which the load of main engines was increased. In particular, the noise of the stern was as high as 92.2dB(A) during the full ahead. Hence, hearing loss may be caused by such a noise, so a variety of regulations on it are determined to be necessary.

Noise is a sound that humans do not want. In this study, noise is measured for C172, the most frequently used general aviation trainer in Korea and abroad. In addition, in this study, noise measurement points are selected for Muan Airport, where most of the domestic training aircraft fly under the supervision of the Ministry of Land, Infrastructure and Transport. Based on this, the measured data is scaled and analyzed. In addition, we intend to analyze what characteristics C172 aircraft have unique through frequency analysis of noise of C172. Through this, it is intended to understand what type of noise training aircraft affect in future studies.

Currently, many complaints have been filed by local residents on helicopter noise while the law on noise prevention and damage compensation at military airfields and military ranges has been in effect since November 27, 2020. The airfields operated by state agencies are inevitably used to defend the country, defend the country, and protect the lives of the people, but various efforts are needed to minimize noise complaints. In general, helicopters operating in a specific area exhibit different noise frequencies depending on the number or size of wings for each type, takeoff speed, and takeoff altitude. Therefore, by measuring and analyzing noise in the take-off stage of a number of helicopters operating in a specific area, this study aims to present more effective noise prevention measures by analyzing the compliance of each type of helicopter with variables such as take-off speed, take-off altitude, and rise rate. Therefore, the results of this study will be significant in terms of resolving complaints and reducing compensation expenditures of local residents around the airport.

ICT 산업의 글로벌 시장을 선점할 수 있는 다음 세대의 개발이 필요한 상황이 일어남에 따라 웨어러블 디바이스 의 생체 신호 모니터링에 대한 관심이 크게 증가하고 있다. 이에 따라 본 연구에서는 히스테리시스가 적은 E-Band를 사용하여 단일벽 탄소나노튜브(SWCNT) 분산 용액에 함침 공정을 통해서 저항형 직물 인장 센서(Resistive textile strain sensor)를 개발하였다. 전기전도성이 부여된 e-band에 저항 신호를 측정하기 위해 만능재료시험기(UTM)과 Microcontroller unit인 아두이노와 LCR 미터를 이용해서 인장의 변화에 따른 저항 변화를 측정하였다. 원단으로 이 루어진 텍스타일 스트레인 센서의 특성상 발생하는 다양한 노이즈들을 효과적으로 처리하기 위하여 신호처리 과정 (Signal processing)의 노이즈 필터링의 이동평균 필터, 사비츠키-골레이 필터, 중앙값 필터들을 사용하여 센서의 필 터 성능을 평가하였다. 그 결과 이동평균 필터의 필터링 결과의 신뢰도가 최소 89.82%, 최대 97.87%으로 이동평균 필터링이 텍스타일 스트레인 센서의 노이즈 필터링 방식으로 적합하였다.

최근 자기공명영상 획득을 위한 시뮬레이션 도구가 개발되어 오랜 시간이 소요되는 임상 연구를 대체할 수 있게 되었다. 이에 본 연구에서는 MRiLab 시뮬레이션을 사용하여 부가인자인 에코 시간의 변화에 따라 경사에코 펄스 시퀀스가 적용된 뇌 T2 강조 영상을 획득하여 영상의 신호 및 노이즈의 변화를 정량적으로 평가하고 경향성을 파악하고자 한다. 이를 위해 실제 MRI 장비를 기반으로 새롭게 개발된 MRiLab simulation tool을 사용하여 모든 파라미터를 같게 고정한 후 TE만을 20~95 ms범위에서 5 ms 간격으로 각각 설정하여 경사에코 펄스 시퀀스가 적용된 뇌 T2 강조 영상을 획득하였다. 획득된 영상들의 신호 및 노이즈 특성 변화를 정량적으로 평가하기 위해 신호대잡음비 및 대조대잡음비를 측정하였다. 결과적으로, TE가 증가할수록 SNR은 감소하고 CNR은 증가하는 경향을 보였다. 이는 TE가 증가할수록 관심 영역으로 설정된 뇌척 수액 신호는 일정하게 유지되는 반면 노이즈는 증가하였으며, 백그라운드로 설정된 백질의 경우 신호가 감소함과 동시에 노이즈가 증가한 것이 원인으로 분석된다. 결론적으로, 진단에 용이한 경사에코 펄스 시퀀스가 적용된 뇌 T2 강조 영상을 획득하기 위해서는 그 목적에 따라 적합한 TE를 설정하는 것이 중요함을 확인하였다.