• Nuclear Engineering and Technology
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• 제39권6호
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• pp.717-724
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• 2007

A measurement-based time-domain noise simulation of radiation detector-preamplifier (front-end) noise in nuclear spectroscopy is described. The time-domain noise simulation was performed by generating "noise random numbers" using Monte Carlo's inverse method. The probability of unpredictable noise was derived from the empirical cumulative distribution function via the sampled noise, which was measured from a preamplifier output. Results of the simulated noise were investigated as functions of time, frequency, and statistical domains. Noise behavior was evaluated using the signal wave-shaping function, and was compared with the actual noise. Similarities between the response characteristics of the simulated and the actual preamplifier output noises were found. The simulated noise and the computed nuclear pulse signal were also combined to generate a simulated preamplifier output signal. Such simulated output signals could be used in nuclear spectroscopy to determine energy resolution degradation from front-end noise effect.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.357-361
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• 2003

According to the remarkable reduction of the vehicle noise, the important of tire noise which is generated from the vehicle and the necessities of the researches for the noise reduction are emphasized. In this study, we have studied the road noise which is excited by the interaction between tire and road. In order to evaluate the road noise, we carry out the subjective test(feeling test). In order to consider the effect of the vehicle suspension for the tire/road noise, we are equipped with identical tires on the differential vehicle suspension and evaluate the road noise. In order to consider the effect of the tire structure for the tire/road noise, we evaluate the some tires with various structures. From the test results, we fine that the difference of road noise is generated by the variation of the vehicle suspension. Also, we can select the optimized tire structure which can be reduced the road noise.

• Journal of information and communication convergence engineering
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• 제9권1호
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• pp.59-63
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• 2011

Conventional noise reduction filtering schemes realize limited improvements of the peak signal-to-noise ratio (PSNR) in the low-level noisy images. The flatness degree and the edge information are effectively used to estimate the noise volume. We propose a noise estimator for reducing noise in the AWGN (additive white gaussian noise) corrupted images using three intermediate image maps (FGM(flatness gray map), FIM(flatness index map), NEM(noise estimate map)). The proposed noise estimator is fed into the conventional noise reduction filters as a pre-processor. The performance of noise reduction is tested in the various AWGN corrupted images.

• 소음진동
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• 제7권6호
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• pp.1001-1006
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• 1997

Railroad noise is one of the main causes of environmental impact. Whenever a new railroad line is planned or a housing project near an existing railroad is proposed, an estimate of the relevant noise levels is usually required. For this, it is necessary to quantify those paramters that affect the railroad noise. This paper presents an accurate prediction of railroad noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.1045-1049
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• 2001

Before building houses or apartments, we need to predict noise propagation to eliminate possible noise problems to residents. However, we do not try to predict noise propagation during estimation of noise effect for the developing area since we did not have a good mathematical model to predict noise level due to a traffic noise. In this article, an adequate mathematical model has been developed and proved to predict noise effect to living area due to a traffic noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.750-753
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• 2006

Noise prediction is required as part of an environmental impact assessment. However, there has not been any comprehensive study or review en the major factors of specific vehicles affecting traffic noise so that there is difficulty when trying to figure out the source of noise. This study was to evaluate the noise effect of specific vehicles passing through a certain road by using noise map.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.1182-1186
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• 2003

Noise map is becoming an increasingly important tool supporting noise policy. In order to main am a quiet environment of urban areas, noise map was developed by using GIS technique which combines geographic and noise informations with a database management system. By evaluating various methods of the spatial anal: sis, it was concluded that the inverse distance weighted method gave the best results and was applied to develope the noise maps of road noise.

• 한국전자파학회논문지
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• 제9권4호
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• pp.552-559
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• 1998

Conducted noise in power line contains both the common mode(CM) and differential mode(DM) noise. These two modes of noise are caused by different noise sources and paths. Therefore, CM/DM noise must be deal with individually in EMI filter. In this paper the technique to separate power line noise is presented, which can be used to measure both the CM and the DM noise from total generated noise. Also, noise-separator is designed and experimental results showed 30 dB above of separation performance in 10 kHz~10 MHz.

• 한국환경과학회지
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• 제6권6호
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• pp.551-562
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• 1997

Nine districts in Seoul were chosen randomly and a questionnaire containing 23 questions was distributed to survey the perception of noise pollution by the citizens. The results were primarily analyzed to understand the perception of Seoul citizen as a whole, and then analyzed according to 4 demographic variables -district area, age, gender and occupation -to see if there were any possible relation between nonnoise variables and noise annoyance. Actual noise level data measured by the city government were used to compare quantified noise level with the surveyed people's perception. It was found that people consider road traffic noise to be the naix source of noise pollution In Seoul and that most people have experienced annoyance in everyday life. Also it was verified that the responsibility for noise control should be on both city government and the individuals, but It was generally considered that very little effort Is actually put Into solong norse pollution from both groups. From the survey, It could be analyzed that domographic variables do affect people In the awareness of noise pollution, and that one's sensitifty and annoyance due to noise increase as one ages. From the study, It was concluded that noise pollution Is not considered currently as a hazardous problem to most Seoul citizens, however specific noise reduction policies, especially regarding road traffic noise, should be put Into practice In the near future.

• 한국소음진동공학회논문집
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• 제21권5호
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• pp.400-407
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• 2011

The suggested method of previous Son's study dichotomized subjective response data to modeling noise exposure-response. The method used maximum liklihood estimation instead of least square estimation and the noise exposure-response curve of the study was logistic regression analysis result. The method was originated to modeling community response rate such as %HA or %A. It can be useful when the subjective response was investigated based on predicted noise level. It is difficult to measure the single source emitting noise such as railway because various traffic noise sources combined in our life. The suggested method was adopted to model in this study and railway noise-exposure response curves were modeled because the noise level of this area was predicted data. The data of this study was used by previous Ko's paper but he dealt the area as combined noise area and divided the data by dominant noise source. But this study used all data of this area because the annoyance response to railway noise was higher than other noise according to the result of correlation analysis. The trend of the %HA and %A prediction model to train noise of this study is almost same as the model based on measured noise of previous Lim's study although the investigated areas and methods were different.