• Title/Summary/Keyword: 소음 진단

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Evaluation on Expectation of Deflection of Floor Damping Materials Subjected to Long-Term Load (장기하중을 받는 바닥완충재의 처짐 예측 평가)

  • Kim, Jung-Min;Hong, Yoon-Ki;Kim, Jin-Koo;Lee, Jung-Yoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.4
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    • pp.19-26
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    • 2016
  • Floor damping materials used in floating floor system to diminish the floor noise have been made with low density and dynamic stiffness. Owing to this low density and dynamic stiffness, the deflection in these materials under long-term loading and cracking of the floor finishing mortar in the floating floor system may occur. This paper presents the results of long-term loading effects on the deflection of different types of floor damping materials. The experimental program involved the long-term loading tests for 490 days loading period on sixteen specimens. Specimens were classified as DM1(Damping Materials) to DM8, depending upon the four main parameters; types, bottom shapes and densities of floor damping materials and amount of loading. Results indicated that the long-term deflection of all specimens of damping materials remained unchanged after 200 days at all loading amounts, except the specimens made up of Polystrene, in which long-term deflection remained unchanged after 160 days at 250 N load and 100 days 500 N load. In this paper, two types of correlation expressions were shown in the deflection range prior to the range where deflection remained constant; two analyses by ISO 20392 and linear regression. In comparison of two analyses and experimental results on the difference of deflection of 16 specimens, the difference of deflection was below 0.4 mm in those analyses in case of that total deflection was below 10 mm. Restrictively, it was judged that the analysis for the deflection of specimens made up of Polystrene is more appropriate using ISO 20392.

Development of Thickness Measurement Method From Concrete Slab Using Ground Penetrating Radar (GPR 기반 콘크리트 슬래브 시공 두께 검측 기법 개발)

  • Lee, Taemin;Kang, Minju;Choi, Minseo;Jung, Sun-Eung;Choi, Hajin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.3
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    • pp.39-47
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    • 2022
  • In this paper, we proposed a thickness measurement method of concrete slab using GPR, and the verification of the suggested algorithm was carried out through real-scale experiment. The thickness measurement algorithm developed in this study is to set the relative dielectric constant based on the unique shape of parabola, and time series data can be converted to thickness information. GPR scanning were conducted in four types of slab structure for noise reduction, including finishing mortar, autoclaved lightweight concrete, and noise damping layer. The thickness obtained by GPR was compared with Boring data, and the average error was 1.95 mm. In order to investigate the effect of finishing materials on the slab, additional three types of finishing materials were placed, and the following average error was 1.70 mm. In addition, sampling interval from device, the effect of radius on the shape of parabola, and Boring error were comprehensively discussed. Based on the experimental verification, GPR scanning and the suggested algorithm have a great potential that they can be applied to the thickness measurement of finishing mortar from concrete slab with high accuracy.

Tunnel Safety Diagnosis in Near-excavation by In-depth Inspection of Tunnel (기존터널 안전진단 결과를 통한 근접시공 시 터널 안정성 평가)

  • Kim, Seok-Jae;Kim, Min-Seok;Kim, Jun-Chul;Yoo, Young-Il;Oh, Joung-Bae;Oh, Sae-Joon
    • Tunnel and Underground Space
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    • v.16 no.4 s.63
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    • pp.347-356
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    • 2006
  • We analyzed case studies doing in-depth inspection of tunnel to maintain safety of existing tunnel in constructing new tunnel near to a existing tunnel with single track. Futhermore, We accomplished in-depth inspection of existing tunnel and numerical analysis. We suggested remedies to security safety of existing tunnel. We applied line drilling and pre-large hole boring method not to have an effect on existing tunnel and convinced the safety of existing tunnel from blast-vibration and blast-noise of numerical analysis. We planed to install basset system to measure displacement of existing tunnel according to excavating new tunnel.

Development of Diagnosis System for Intelligent High-Speed Micro-Machining and Evaluation of Micro-Machining Characteristics (고속.지능형 마이크로머시닝을 위한 진단시스템 및 특성평가)

  • 김흥배;이우영;최성주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.993-998
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    • 1997
  • The advanced technology of micro-machining is starting to penetrate our lives. This technology, with which it is possible to make micro-structures by means of processing on the order of nm (micrometer = 1/1,000 mm) or less, is realizing machines that were only part of our wildest imagination. However, the fact is that many issues remain in the quest for a variety of applications. With the advent of computing technologies, information technologies, and telecommunications technologies, we foresee the need for new approaches in design, process, and the use of materials, technologies, and people in a globalized manufacturing enterprise. A new thinking paradigm is needed to focus on quality of service on the products we design and manufacture. Factories in different regions need to be co-ordinated through use of the state-of-the-art information on productivity, diagnostics, and service evaluation of manufacturing systems could be shared among different locations and partners. In this research, We develope the internet based Diagnosis system for micro machining and evaluate its characteristics by using mechatronic sensor like Dynamometer, acoustic emission, Acceleration sensor, micro phone, vision, infra-red thermometer.

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Development of a Lifetime Test Bench for Robot Reducers for Fault Diagnosis and Failure Prognostics (고장 진단 및 예지가 가능한 로봇용 감속기 내구성능평가 장치 개발)

  • Shin, Ju Seong;Kim, Ju Hyun;Kim, Jong Geol;Jin, Maolin
    • Journal of Drive and Control
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    • v.16 no.3
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    • pp.33-41
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    • 2019
  • This study presents the development of a lifetime test bench for the strain wave reducer which is a precision gear reducer of the robot to realize fault diagnosis and failure prognostics. To this end, the lifetime test bench was designed to detect the vertical forward/reverse direction rotation load. Through the lifetime test bench, it is possible to apply the same load spectrum from robot working scenarios. We developed a data integration gateway for fault data collection. Through the development of dedicated software for fault diagnosis and failure prognostics, these data from vibration, noise and temperature sensors were collected and analyzed along with the operation of the lifetime evaluation.

Case about cardiogenic general edema of Soeumin apoplexy patient (소음인(少陰人) 전신부종(全身浮腫)에 대한 증례(證例))

  • Shin, Mi-ran;Kim, Sun-hyung;Kim, Dal-rae
    • Journal of Sasang Constitutional Medicine
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    • v.12 no.1
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    • pp.265-270
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    • 2000
  • Occasionally, apoplexy is caused by functional or physiologic cardiopulmonary abnormality. In addition, theses may become the factor of aggravating apoplexy and involve complication. If patient has cardiopulmonary disease, progressing of apoplexy is commonly used to be accelerate and prognosis is deteriorative. There by the patient who has cardiopulmonary disease, should be particularly treated for cardiopulmonary disease. We got good result, during treat Soeumin cerebral vascular infarction patient who has pulmonary edema leaded from congestive heart failure, with Sasang Constitutional treatment. Therefore I reported them here. She was 68 years old, female patient. She visited our hospital for apoplexy with right side hemiparesis, dysphagia, dysphasia. After her admission into our hospital, we knew that she has congestive heart failure. The diagnosis is established. She presented with severe general edema and pulmonary edema. Although Soeumin edema usually classified as Taiyin Disease, we classified this as Shaoyin Disease, through diet, discharge, sleep, tongue and symptoms. We has prescribed Gungguichongsoyijung-tang(芎歸蔥蘇理中湯) in accordance with the principle of invigorating the Spleen and lower Yin(建碑而降陰). And her symptoms has improved.

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병원에서의 산업보건관리

  • Jeon, Gyeong-Ja
    • Korean Journal of Occupational Health Nursing
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    • v.2
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    • pp.40-51
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    • 1992
  • 본 연구는 병원에서의 산업보건관리 실태를 파악하기 위하여 전국에 있는 병원을 대상으로 1992년 12월 1일부터 1993년 1월 23일까지 설문조사를 설시하였다. 설문조사에 응당한 병원은 41개병원으로 회수율은 51.9%였다. 조사에 이용된 설문지는 산업안전보건법 내용을 기초로 하여 본 연구자가 작성한 것이며 안전보전에 관한 제반 규정, 안전보건관리체계, 근로자건강관리, 작업환경관리, 보건교육, 보건관련시설, 질병 및 상해에 대한 보상 등에 관한 45개문항으로 구성되어 있다. 분석결과는 다음과 같다. 첫째, 전체 병원 중 68.3%가 안전보건관리 규정이 있다고 답하였으며, 77.5%의 병원이 단체협약 중 근로자의 안전과 보건에 관한 조항을 포함시키고 있는 것으로 나타났다. 단체협약에 포함된 내용 중에는 정기건강진단(23.7%)과 질병 및 상해에 대한 보상(20.9%), 안전보건위원회의 구성(18.1%)등이 많았다. 둘째, 대상 병원중 66.7%가 안전보건관리책임자, 관리감독자, 안전담당자를 두고 있는 것으로 나타났고, 근로자수가 1,000명 이상인 병원은 83.3%가 이들 인력을 선임하고 있다. 그러나, 보건관리자와 안전관리자를 전담으로 두고 있는 경우는 한 곳도 없었으며 50%이내에서 겸직으로 선임하고 있었다. 또한, 안전보건위원회를 운영하고 있거나 노사협의회로 이를 대치하고 있는 병원은 54.2%로 절반 수준에 머물렀고, 그나마 정기적으로 운영을 하고 있다고 답한 병원은 3개 병원 밖에 되지 않았다. 세째, 근로자 건강관리를 위한 건강진단 실시 현황을 보면, 채용시검진 97.6%, 일반건강진단 100.0%, 특수 건강진단 24.4%가 실시하고 있었다. 건강진단에서 주로 실시하고 있는 항목은 흉부 X선검사, 시력, 혈압, 혈청GOT/GPT, 체중, 신장등이었다. 그러나, 병원에서 감염될 수 있는 기회가 높은 간염항원/항체검사의 실시율은 85.7%로 아직도 실시하지 않는 병원이 있음을 알 수 있다. 네째, 작업환경관리를 위하여 정기적으로 환경측정을 실시하는 병원은 21.6%였고 주로 측정하는 항목은 방사선이었다. 특히 소음, 조명, 분진에 대한 측정이 이루어지지 않음은 근로자뿐아니라 환자의 안위에도부정적인 영향을 미칠 수 있다. 다섯째, 안전한 작업과 근로자의 건강을 위하여 정기적인 보건교육을 설시하고 있는 병원은 불과 5.6%였다. 교육내용은 주로 안전에 관한 것이었다. 여섯째, 근로자의 일상적인 건강문제를 해결해주는 의무실을 독립적으로 마련하고 있는 병원은 한 곳도 없었고, 교대근무자나 당직자를 위한 수면시설은 44.7%, 작업 후에 사용할 수 있는 샤워시설은 35.1%의 병원이 마련하고 있었다. 일곱째, 근무중 다치거나 병에 걸렸을 때 치료비에 대한 부담은 대체로 병원이 하고 있으며 치료기간 중 근무는 병가나 휴직으로 처리되고 있다. 이는 병원이 산재보상보험법에 적용을 받지 않은 사업으로 분류되어 있는 현실에 기인된 것으로 보상과 관련된 부담을 병원이나 근로자 모두가 안게 되는 결과를 초래하게 되는 것이다. 이상에서 볼 때 병원근로자를 위한 산업보건관리는 주로 건강진단과 질병 및 상해에 대한 보상제도가 이루어지고 있는 실정이다. 그러므로 질병의 예방이나 악화방지 나아가 건강증진을 도모하기 위한 지속적인 노력을 기울이고 있는 병원은 전무한 상태임을 알 수 있다. 이러한 현실을 병원근로자를 위한 산업보건관리에 대한 인식이 전반적으로 부족함을 드러내는 것으로 이를 개선하기 위한 보다 적극적인 노력이 시급히 요청되고 있다.

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Evaluation of the Railroad Track Life Cycle Based on the Metro Rail Wear Data Regression Analysis (지하철 마모 데이터 회귀분석을 통한 궤도 수명 평가)

  • Jeong, Min-Chul;Kim, Jung-Hoon;Lee, Jee-Ha;Kang, Yun-Suk;Kong, Jung-Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.4
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    • pp.86-93
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    • 2010
  • The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

Time-Frequency Analysis Using Linear Combination Wavelet Transform and Its Application to Diagnostic Monitoring System (선형조합 웨이브릿 변환을 사용한 시간-주파수 분석 및 진단 모니터링 시스템의 적용)

  • 김민수;권기룡;김석태
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.1
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    • pp.83-95
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    • 1999
  • Wavelet transform has localization for time or frequency. It is useful to analyze a nonstationary signal. Basic function on wavelet transform is generated dilating and translating the original wavelet(mother wavelet). In this paper, time-frequency analysis method using linear combination wavelet transform is proposed. And it is applied to diagnostic monitoring system using the proposed linear combination wavelet transform. The stationary and nonstationary signal is used linear chirp signal, fan noise signal, a sinusoid signal from revolution body, electronic signal. Transform applied to signal analysis use fast Fourier transform (FFT), Daubechies, Haar and proposed linear combination method. The result of time-frequency analysis using linear combination wavelet transform is suited for portraying nonstationary time signal as well as stationary signal. Also the diagnostic monitoring system carry out the effective the signal analysis.

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Usefulness of Acoustic Noise Reduction in Brain MRI Using Quiet-T2 (뇌 자기공명영상에서 Quiet-T2 기법을 이용한 소음감소의 유용성)

  • Lee, SeJy;Kim, Young-Keun
    • Journal of radiological science and technology
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    • v.39 no.1
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    • pp.51-57
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    • 2016
  • Acoustic noise during magnetic resonance imaging (MRI) is the main source for patient discomfort. we report our preliminary experience with this technique in neuroimaging with regard to subjective and objective noise levels and image quality. 60 patients(29 males, 31 females, average age of 60.1) underwent routine brain MRI with 3.0 Tesla (MAGNETOM Tim Trio; Siemens, Germany) system and 12-channel head coil. Q-$T_2$ and $T_2$ sequence were performed. Measurement of sound pressure levels (SPL) and heart rate on Q-$T_2$ and $T_2$ was performed respectively. Quantitative analysis was carried out by measuring the SNR, CNR, and SIR values of Q-$T_2$, $T_2$ and a statistical analysis was performed using independent sample T-test. Qualitative analysis was evaluated by the eyes for the overall quality image of Q-$T_2$ and $T_2$. A 5-point evaluation scale was used, including excellent(5), good(4), fair(3), poor(2), and unacceptable(1). The average noise and peak noise decreased by $15dB_A$ and $10dB_A$ on $T_2$ and Q-$T_2$ test. Also, the average value of heartbeat rate was lower in Q-$T_2$ for 120 seconds in each test, but there was no statistical significance. The quantitative analysis showed that there was no significant difference between CNR and SIR, and there was a significant difference (p<0.05) as SNR had a lower average value on Q-$T_2$. According to the qualitative analysis, the overall quality image of 59 case $T_2$ and Q-$T_2$ was evaluated as excellent at 5 points, and 1 case was evaluated as good at 4 points due to a motion artifact. Q-$T_2$ is a promising technique for acoustic noise reduction and improved patient comfort.