• Title/Summary/Keyword: Vibration Exposure

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Acoustic Amenity Assessment of Urban Environmental Sound for the Ecological Soundscape (친환경 사운드스케이프 조성을 위한 도시 환경음의 쾌적성 평가)

  • Jang, Gil-Soo;Kook, Chan;Shin, Hoon;Ki, No-Gap
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.678-681
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    • 2005
  • The assessment of an urban site depends on the way it responds to multiple needs such as functionality, aesthetic and complex comfort of acoustic, thermal, lighting and air quality This study aims to investigate the assessment of various urban soundscapes in the sense of acoustic amenity by the questionnaires. As a result, acoustic amenity assessment was influenced by the non-acoustic factors such as environment assessment of visual, thermal, air quality etc.. And it was shown that the subjects tend to perceive the noise level less than 3$\sim$10dB L$_{Aeq}$ under the similar noise exposure level according to the urban landscapes.

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Suggestion of Prediction Equation for Environmental Noise of Saemaeul Trains (새마을 열차 환경소음 예측식 제안)

  • Cho, Jun-Ho;Kim, Jae-Chul;Koh, Hyo-In;Han, Hwan-Su
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.371-376
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    • 2005
  • For the reduction and efficient management of railway noise, first of all prediction of railway noise is necessarily requisited. Many studies for prediction of railway nearby noise have been accomplished. But it is impossible to predict easily and exactly for the Korean Railway, because the acoustic powers for each rolling stock operated in Korea have not been built yet. So in this study, prediction model equation for environmental noise for Korean rolling stock Saemaeul was suggested using SEL of engine and roiling noise component separately. Finally for the validation of prediction equation, the predicted result was compared to the measured.

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Study on the Noise-mapping Procedure in Korea and Application of Nosie map (국내의 소음지도 제작과 활용에 대한 연구)

  • Oh, Jin-Woo;Chang, Seo-Il;Lee, Ki-Jung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.778-781
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    • 2004
  • Recently, one of the reason of noise problems is urban planning has little concern about noise. For solving noise problems, strategic action is needed during urban planning. The noise map is one of the solution for concerning about noise in urban planning and EC has been studied the noise map for the strategic purpose since 1970s. The noise map is powerful tool for predicting sound level, calculating exposure population and evaluating the efficiency of the noise reduction plan. In Korea, The noise map is a unfamiliar field. The experience is few for noise-mapping and the noise mapping procedure has not been standardization yet. For activation of noise map, the study about fundamental problems of collecting data md noise-mapping procedure must be need. This paper is for studying on the noise-mapping procedure in Korea and application of noise map.

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Analysis on the Suporting Integrity of the PWR Fuel Rod (경수로 핵연료봉 노내지지 건전성 해석)

  • 임정식;구양현;윤경호;손동성
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.10a
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    • pp.177-183
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    • 1997
  • The fuel rod for PWR is supported by the spring of the sapcer grid to maintain its axial location and lateral space between fuel rods to get proper functions during the residence in the reactor. The long exposure duration makes the spring to be relax and loss the spring force that results in a fuel rod rattling which may cause fuel rod failure. Here considering the spring behaviour as a function of burnup the reaction forces of the springs are calculated by the finite element program developed herein to evaluate the integrity of the fuel rod from fretting. The results are compared with previous data and ANSYS for the validation of the program and procedures.

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Proteomic Changes in the Sound Vibration-Treated Arabidopsis thaliana Facilitates Defense Response during Botrytis cinerea Infection

  • Ghosh, Ritesh;Choi, Bosung;Kwon, Young Sang;Bashir, Tufail;Bae, Dong-Won;Bae, Hanhong
    • The Plant Pathology Journal
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    • v.35 no.6
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    • pp.609-622
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    • 2019
  • Sound vibration (SV) treatment can trigger various molecular and physiological changes in plants. Previously, we showed that pre-exposure of Arabidopsis plants to SV boosts its defense response against Botrytis cinerea fungus. The present study was aimed to investigate the changes in the proteome states in the SV-treated Arabidopsis during disease progression. Proteomics analysis identified several upregulated proteins in the SV-infected plants (i.e., SV-treated plants carrying Botrytis infection). These upregulated proteins are involved in a plethora of biological functions, e.g., primary metabolism (i.e., glycolysis, tricarboxylic acid cycle, ATP synthesis, cysteine metabolism, and photosynthesis), redox homeostasis, and defense response. Additionally, our enzyme assays confirmed the enhanced activity of antioxidant enzymes in the SV-infected plants compared to control plants. Broadly, our results suggest that SV pre-treatment evokes a more efficient defense response in the SV-infected plants by modulating the primary metabolism and reactive oxygen species scavenging activity.

Improvement of Dynamic Characteristics of an Optical Image Stabilizer in a Compact Camera (초소형 카메라 흔들림 보정장치의 동특성 개선)

  • Song, Myeong-Gyu;Son, Dong-Hun;Park, No-Cheol;Park, Kyoung-Su;Park, Young-Pil
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.2
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    • pp.178-185
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    • 2011
  • Optical image stabilization is a device to compensate the camera movement in the exposure time. The compensation is implemented by movable lens or image sensor that adjusts the optical path to the camera movement. Generally, the camera is moved by a handshake, thus the handshake is considered as an external disturbance. However, there are many other vibrations such as car and train vibration. In this paper, the optical image stabilization system in high frequency region is presented. Notch filter and lead compensator are designed and applied to improve the stability without changing the actuator. To verify the performance of the optical image stabilization system in high frequency region, the experiment equipment with moving object is established. It is confirmed that the opticalimage stabilization system does not diverge at the resonance frequency.

A Study on the Evaluation Metric of a Civil Aircraft Noise (민간항공기 소음평가 단위에 관한 연구)

  • Lee, Jun-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.5 s.110
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    • pp.503-513
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    • 2006
  • The duration time of aircraft noise event is also an important factor for the evaluation of civil aircraft noise, which is considered as a notable characteristic of military aircraft noise. SEL is proved as a suitable noise metric for the measuring military aircraft noise of various flight pattern considering the duration time of noise event. This study reviews whether SEL is a suitable for measuring civil aircraft noise and study shows SEL is fairly compensating the duration time of civil aircraft noise event for the evaluation of aircraft noise. Noise metric for the evaluation aircraft noise based on SEL is more appropriate than based on $L_{MAX}$ for compensating duration time of noise event either military aircraft or civil aircraft. In this reason, current formula of WECPNL based on energy average of measured $L_{MAX}$ for the evaluation of aircraft noise impact in 'Test Method of Noise and Vibration of Korea' is recommended to be amended to formula of WECPNL based on energy average of measured SEL considering compensation of noise event duration time, if WECPNL is not based on measured EPNL, a metric compensating duration time.

Development of the Railroad Geotechnical Information Management System Using Web GIS (웹 GIS 기반 철도 지반정보 관리프로그램의 개발)

  • 황선근;이성혁;김현기;김정무
    • Journal of the Korean Society for Railway
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    • v.7 no.1
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    • pp.20-25
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    • 2004
  • Railroad geotechnical information management system was developed by using Web GIS and DB in this study. The standardization of railroad geotechnical information is progressed by classifying three groups as like basic informations, vibration informations along railway lines and design drawings. The basic informations consisted of basic and dynamic properties of soils, geophysical exploration and seismic survey/exploration. And the specification for 'human exposure to whole-body vibration' was adopted to construct the vibration informations along railway lines. The informations as like drawings and photographs were saved by changing to graphic files in the standardization of design drawings. In the case of standardization of geographical information, the topographical maps(NGIS, 1:5000) were primarily used as digital maps. Another digital maps(KRRI, 1:5000) and their geographical DB based on NGI code system were added on this maps. The standardized informations were used to construct their database. And railroad information management system was developed using Entity-Relation(ER) model which had a good feasibility for expansion and transition to other system in designing stage of database. This system consisted of layer selection, search and analysis of geotechnical informations and Zeus DB was adopted for GIS operating and user interface. This system could be a good tool for saving, searching and analyzing the geotechnical and geophysical informations. These DB systems would offered the basic informations to plans, design and construction of railroad lines etc. in practical use.

Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

  • Dong, Ren G.;Sinsel, Erik W.;Welcome, Daniel E.;Warren, Christopher;Xu, Xueyan S.;McDowell, Thomas W.;Wu, John Z.
    • Safety and Health at Work
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    • v.6 no.3
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    • pp.159-173
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    • 2015
  • The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

Exposure assessment of musculoskeletal disorder risk factors in non routinized work: An application of PATH-KOSHA observational tool to hospital workers (비정형작업 근골격계질환 위험요인의 노출평가: 일부 병원근로자에 대한 PATH-KOSHA 관찰도구 적용사례)

  • Park, Jung-Keun;Han, Young-Sun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.19 no.4
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    • pp.412-422
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    • 2009
  • This study was conducted to assess exposure to musculoskeletal disorder(MSD) risk factors in hospital personnel who performed non-routinized work tasks. A tool ("PATH-KOSHA" version) was newly revised from PATH(Posture, Activity, Tools and Handling) method and uploaded into a personal digital assistant(PDA). The version was used, on a basis of direct-observation, to collect PATH data at the 2 hospital settings in different regions. Job analysis was performed to get various information (e.g., work and rest time, task type) as well. The data collected were visually checked for data cleaning and stored for future data analysis. A total of 1,992 PATH observations were made for 37 hospital workers. Exposure levels varied across 18 items of the MSD risk factors. The highest percent time spent on non-neutral postures was 53% for wrist deviation, followed by 47%(pinch grip), 35%(trunk posture), 23%(neck posture), and 20%(shoulder/arm posture). The highest percent time spent among hand activity level(HAL) variables was 55% for HAL-cat2 (HAL: 3.3 - <6.7). The percent time of items with respect to both loads with more than 5kg and contact stress was less than 4%. Vibration was not exposed in the study workers. Different aspects were discussed for findings. The study results showed that wrist deviation was highest in percent time spent on awkward posture while HAL-cat2 was highest in hand repetition. The study suggests that distal upper extremity posture and HAL should be primarily addressed and controlled in non-routinized work including the hospital settings.