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  • Title/Summary/Keyword: 소음 감소

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Control of Parallel Hybrid Electric Vehicle using AI Logic (인공지능을 이용한 병렬 복합형 전기자동차 구동 시스템의 제어)

  • Koo, Euh-Suh;Kim, Woo-Suk;Choi, Hyun-Sung;Lee, Hyeoun-Dong;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.527-530
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    • 1997
  • 최근 환경에 대한 각국의 관심이 높아지면서 자동차의 배기가스 및 소음에 관한 규제 차들이 날로 높아 가고 있는 실정이다. 이에 대한 해결책의 하나로 전기 자동차에 관한 관심이 고조되고 있으며, 특히 기계적 에너지와 전기적 에너지를 동시에 제어함으로써 외부의 별도 전원 공급이 필요 없이 구동이 가능한 병렬 복합형 전기자동차가 많은 연구의 대상이 되고 있다. 병렬 복합형 전기자동차의 전동기는 저속에서 구동 회전력을 보조하여 배기가스와 소음을 감소시키며, 고속에서는 내연 기관으로부터 에너지를 공급받아 배터리를 충전한다. 본 논문에서는 인공지능을 이용하여 다양한 주행 조건, 운행 패턴 등에 효과적으로 대응할 수 있으며 배기가스 및 소음을 감소시킬 수 있는 운행 제어 알고리즘을 제안하고 이를 주행시험을 통하여 그 타당성을 입증하였다.

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Analysis of Traffic Noise for Single and Double Layered Porous Pavement with SPB Method -National Route 1, Sejong-Si Section- (SPB측정법에 의한 복층 및 단층 다공성포장의 소음분석 -국도 1호선 세종시 구간-)

  • Yoo, In-Kyoon;Lee, Su-Hyung;Han, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.92-102
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    • 2020
  • Porous pavement (PP) has attracted attention as a new alternative measure against road traffic noise. PP refers to pavement that reduces the fines in the asphalt mixture to form voids. These voids can reduce traffic accidents and friction noise. For active application, verification of the noise reduction effect is required. In this study, the noise reduction of single-layer PP(SLPP) and double layer PP(DLPP) was analyzed. First, the Sejong section was selected, and traffic noise was measured using the SPB method on the roadside. The traffic volume, speed, and mixing ratio of large vehicles were measured. As a result, the DLPP was evaluated to be 7.95 dB(A) smaller on average and 7.57dB(A) smaller at the 95% reliability level than the SLPP. The traffic volume was more influential than the speed and the mixing rate of large vehicles. As the traffic volume increased, the noise increased, but the difference in noise between the two pavements decreased gradually. The results showed that the most effective way to reduce road traffic noise is to change the road pavement rather than reduce traffic speed, restrict traffic for heavy vehicles, or reduce traffic volume.

A Numerical Study on Analysis of Low Frequency Aero-acoustic Noise for a HAWT of NREL Phase VI (NREL Phase VI 수평축 풍력터빈의 저주파 공력소음 해석에 관한 수치적 연구)

  • Mo, Jang-Oh;Lee, Young-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.8
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    • pp.1170-1179
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    • 2009
  • The purpose of this work is to predict the low frequency aero-acoustic noise generated from the horizontal axis wind turbine, NREL Phase VI for the whole operating conditions of various wind speeds using large eddy simulation and Ffowcs-Williams and Hawkings model provided in the commercial code, FLUENT. Because there is no experimental data about wind turbine noise, we first of all compared aerodynamic performance such as shaft torque and power with experimentally measured value. Performance results show a good agreement with experimental data within about 0.8%. As the wind speed increases, the overall sound pressure level and the sound pressure level by the quadrupole and dipole source show a increasing tendency. Also, sound pressure level is proportional to r2 in the near field and r1 in the far field according to the increase of distance from the center of hub of wind turbine. According to 2 times increase of distance, sound pressure level is reduced by about 6dB.

A study of the Indoor-Impulse Noise Attenuation Effect for the Hearing Protection Devices (청각 보호 장구의 실내 충격소음 차음성능에 관한 연구)

  • Chung, Sung-Hak;Song, Kee-Hyeok
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.5
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    • pp.37-42
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    • 2014
  • The objective of this study is the frequency of the noise source 170 dB level of impulsive sound attenuation performance by earplugs to identify, to analyze the frequency characteristics of a shape and pattern. The attenuation performance of the impulsive noise by the frequency levels on the Combat Arm and 3M Form types 1100 Earplugs were evaluated. In order to check the sound attenuation performance of the B&K head and torso simulator and sound attenuation performance of the ear simulator data was verified. Previous studies have most impact, even in the noise source and the impulse noise level is 140 dB, but this study is higher than that of the impulsive noise source features. The results of the impulse noise attenuation effect is frequency-dependent mean 28.58 dB.

Comparative analysis of noise from three Falcon 9 launches (Falcon 9 로켓 3회 발사 소음의 비교 분석)

  • Mathews, Logan T.;Gee, Kent L.;Hart, Grant W.;Rasband, Reese D.;Novakovich, Daniel J.;Irarrazabal, Francisco I.;Vaughn, Aaron B.;Nelson, Pauline
    • The Journal of the Acoustical Society of Korea
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    • v.39 no.4
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    • pp.322-330
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    • 2020
  • This study investigates the far-field noise from three Falcon 9 vehicle launches from Vandenberg Air Force Base, CA, USA, as measured from the same location within the nearby community of Lompoc. The overall sound pressure levels for the three launches are shown to be similar, but some differences in the early launch period are thought to be weather-related. The peak directivity angle in overall level is approximately 65 deg, which is consistent with horizontally-fired, static rocket data. For the third launch, waveforms and spectra are analyzed for different events during the launch sequence. The measured spectral bandwidth decreases with time, but spectral levels remain above the ambient noise throughout the main-engine firing. Additionally, late-launch phenomena observed in the data appear to be correlated with main-engine cutoff and second-stage engine start.

Performance Evaluation Based on Low-Noise Asphalt Pavement Use (저소음 아스팔트 포장 공용에 따른 성능평가)

  • Hwijae Shin;Sungho Mun
    • Land and Housing Review
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    • v.15 no.3
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    • pp.165-175
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    • 2024
  • As living standards improve, the demand for quiet and comfortable environments is increases. However, noise sources are rising due to population growth, urbanization, and industrialization. One solution to this problem is low-noise asphalt pavement, which has fewer installation regulations and can reduce noise at the source. Despite its advantages, there are few evaluation cases and no domestic guidelines for low-noise asphalt pavement. This study aims to evaluate the overall performance of low-noise asphalt pavement on roads in Seoul, focusing on average noise levels, skid resistance, and permeability. Noise measurements were conducted using a digital noise analyzer according to the Ministry of Environment's standards. Results indicated that noise reduction was maintained for 1 to 2 years but decreased over time. Skid resistance, assessed with the British Pendulum Tester, showed excellent performance with values above the standard of 57 in the initial stages after paving. Permeability, evaluated using the KS F 2394 method, was initially effective across all sections but declined over time.

Raynoise를 이용한 철도소음의 예측에 관한 연구

  • 김태구;박민수;박철우;김광일
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2003.10a
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    • pp.286-292
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    • 2003
  • 철도는 1960년대 산업화 이후 급속한 도시화 과정에서 인구의 집중, 도시의 비대화로 인해 늘어나는 교통의 수요와 대량운송 및 정시운행이라는 장점으로 국가산업의 발전과 국민편익에 편리함을 제공하는 등의 지대한 공헌을 하였다. 그럼에도 불구하고, 이러한 발전과 편리함 속에 소음과 진동의 환경공해를 유발하여 철도 주변에 위치하고 있는 거주시설 및 상업시설 등의 거주민들이 생활을 영위함에 있어 불쾌감, 수면방해, 집중력 감소, 시설물의 피해 등의 영향을 주고 있다.(중략)

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Implementation of Noise Reduction for Digital Video Camcorder (디지털비디오캠코더 소음 저감 알고리즘 구현)

  • Park Jaeha;Oh Yoonhak;Lee Hyuckjae
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.249-252
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    • 2004
  • 본 논문에서는 TeakLite DSP 프로세서를 이용하여 캠코더에서 레코딩을 할 때 모터 소음과 주변 잡음이 입력되어 오디오 신호의 명료도가 떨어지는 문제점을 해결하기 위한 잡음 제거 기법의 실시간 구현에 대해서 기술하고자 한다. 잡음 제거를 위해서는 일반적으로 많이 사용되고 있는 Spectral Subtraction 기법을 사용하였다. 알고리즘 구현시 MIPS 감소에 효과적이었던 최적화 기법들을 적용하여 TeakLite DSP 프로세서에서 최적화되어 동작하도록 하였다. 최적화된 Spectral Subtraction 어셈블리 코드는 TeakLite DSP 프로세서에서 32 kHz, 16 bit 입력에 대해 40 MIPS에서 동작하였다.

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Vibration Control of Press for soundproof barrier (타공형 방음벽 프레스의 방진대책)

  • 정정교;박진일;박해동;김두훈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.656-661
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    • 2001
  • 생산 현장의 진동환경은 부품생산활동과 관련된 공정변수중 대표적인 것으로 기계 부품 생산의 품질 및 생산품의 불량률에 큰 영향을 미치며 또한 주변으로 전파된 진동은 우수한 진동환경을 요하는 다른 생산장비에 나쁜 영향을 미치기도 한다. 본 연구의 대상은 공장의 이전으로 인한 환경변화에 의해 발생한 타공형 방음벽 생산 프레스의 진동을 제어하기 위해 바닥의 진동가속도 레벨을 측정하고 DIN 5140에 제시된 기준에 적합하도록 방진 시스템을 설계하였으며 그 결과 방진전과 비교하여 약 20 ㏈ 가량의 바닥 진동 가속도 레벨이 감소하였다.

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