• KIEAE Journal
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• v.16 no.6
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• pp.135-142
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• 2016

Purpose: The purposes of this paper are to investigate effects of indoor thermal environment on acoustical perception and effects of acoustics on indoor thermal perception, and to understand basic human perception on indoor environment. Method: Subjective assessment was performed in an indoor environmental chamber with 24 university students. Thermal conditions with PMV -1.53, 0.03, 1.53, 1.83 were simulated with a VRF system, a humidifier, a dehumidifier, and a ventilation system. Six noise sources - Cafe, Fan, Traffic, Birds, Music, Water- with sound levels of 45, 50, 55, 60 dBA were played for 2 minutes in random order. Temperature sensation, temperature preference, humidity sensation, humidity preference, noisiness, loudness, annoyance, and acoustic preference were assessed using bipolar visual analogue scales. The ANOVA and Turkey's post hoc test were used for data analysis. Result: Thermal environmental perceptions were not altered through 2 minutes noise exposure. Acoustical perceptions were altered by thermal conditions. The results were consistent with previous papers, however, the noise exposure time should be carefully considered for further development.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1268-1271
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• 2006

This paper introduces what amount of railway vibration level observed from residential area. Five residential area located near the railway were selected to measure the vibration levels generated by the different types of Korean railway vehicles. Those 3-axis vibration measurements are applied to the frequency-dependent weighting functions recommended by ISO 2631-2, which are used to evaluate the 3-axis combined vibration levels such as peak levels, L 10 levels and root-mean-squared values. These evaluated results are shown to indicate the environmental vibration severity for the different residential area. In addition to those physical vibration measurements, the survey of subjective responses of residents was also carried out by distributing the questionnaire suggested by WHO. The questionnaire includes the subjective scales for assessing the annoyance and the sleep-disturbance caused by the environmental vibration. The statistical analysis results collected from 386 respondents are introduced. The highly annoyed population and the highly sleep-disturbed one are examined to identify the .elation between their subjective scale and their corresponding environmental vibration levels. These attempts are shown to lead to the salient model to relate the environmental vibration level and the subjective responses of Korean residents to annoyance and sleep-disturbance.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.2
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• pp.99-104
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• 2013

Assessment of noise exposed population is to check the environmental noise level and social influence in order to reduce the risks such as annoyance and disturbance that are generated by environmental noise. Also, this method suggests the preferential noise abatement policy and action plan by accurately finding the area that the noise causes harmful effect to human health. Recently, a noise map, which can predict noise in comprehensive areas, is used for the assessment of noise exposed population, breaking from the methods using existing measures. In particular, countermeasure for the noise can be considered more effectively by using assessment methods of noise exposed population for specific noise levels, areas, and building types which are the main input factors in noise maps. In this study, assessment methods of noise exposed population by using 2 dimensional noise map are compared with those by 3 dimensional noise map.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.523-526
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• 2007

Currently, there are various sounds in the urban surrounding environment such as natural, human, mechanical or sound, etc., and these urban environmental sounds remain in several memories according to magnitude, repetition, learning and experience of sounds. However, there are limitations in memorizing these environmental sounds, thus they are forgotten or reminded, or replaced with new ones from time to time. This study was attempted to look into the changes of the memory of noisiness annoyance and sharpness of the suggested sound sources with urban environmental sounds as time goes by and the order of memorization of the sound sources.

• Journal of KSNVE
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• v.7 no.5
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• pp.827-836
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• 1997

To suggest the standard of railroad noise and its measures and grasp its status 15 open sites of the Jungang. Taeback and Youngdong line in which the background noise level is very low and the railroad is at grade and 7 urban sites of the Kyungboo and Honam line were selected and the sound level which 373 trains passing through the former and 271 trains passing through the latter emitted was investigated. The community response of railroad noise was surveyed for apartment near wayside. Noise reduction of wall for apartment at the wayside was investigated. The prediction of electric train subway noise is derived for the environment impact assessment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.436-441
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• 2007

This study was carried out to evaluate health effects of aircraft noise using THI(Todai Health Index). The questionnaire survey was conducted around the Gimpo International Airport in Seoul, Korea from 8 August to 9 September. Study subjects, 614 residents, were divided into three groups following to the aircraft noise level: under 75WECPNL(area(1)), $75{\sim}80$WECPNL(area(2)) and $80{\sim}85$WECPNL(area (3)). Twelve scale scores are converted to dichotomous variables based on scale scores of 90 percentile value or 10 percentile value in the control group. Logistic regression analysis taking twelve scores converted as the dependent variables and WECPNL(area), age, gender as the independent variables is conducted. Significant dose-response relationships are found in the scale of MOUT, DEPR, NERV, LIFE, where p denotes significance probability of trend test. Factor analysis was carried out and 2 factors are extracted which may be called "somatic factor" and "mental factor". The dose-response relationship with these factors and noise exposure is not clear. But strangely the odds ratio of mental factor in area 2 is the highest and the annoyance of this area is also higher than other areas.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.39-48
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• 2014

Objective: This entire study has two parts. Study I aimed to develop a psychological assessment scale and the study II aimed to investigate the effects of LFN (low frequency noise) on the psychological responses in humans, using the scale developed in the study I. Background: LFN is known to have a negative impact on the functioning of humans. The negative impact of LFN can be categorized into two major areas of functioning of humans, physiological and psychological areas of functioning. The physiological impact can cause abnormalities in threshold, balancing and/or vestibular system, cardiovascular system and, hormone changes. Psychological functioning includes cognition, communication, mental health, and annoyance. Method: 182 college students participated in the study I in development of a psychological assessment scale and 42 paid volunteers participated in the study II to measure psychological responses. The LFN stimuli consisted of 12 different pure tones and 12 different 1 octave-band white noises and each stimulus had 4 different frequencies and 3 different sounds pressure levels. Results: We developed the psychological assessment scale consisting of 17 items with 3 dimensions of psychological responses (i.e., perceived physical, perceived physiological, and emotional responses). The main findings of LFN on the responses were as follows: 1. Perceived psychological responses showed a linear relation with SPL (sound pressure level), that is the higher the SPL is, the higher the negative psychological responses were. 2. Psychological responses showed quadric relations with SPL in general. 3. More negative responses at 31.5Hz LFN than those of 63 and 125Hz were reported, which is deemed to be caused by perceived vibration by 31.5Hz. 'Perceived vibration' at 31.5Hz than those of other frequencies of LFN is deemed to have amplified the negative psychological response. Consequently there found different effects of low frequency noise with different frequencies and intensity (SPL) on multiple psychological responses. Conclusion: Three dimensions of psychological responses drawn in regard to this study differed from others in the frequencies and SLP of LFN. Negative psychological responses are deemed to be differently affected by the frequency, SPL of the LFN and 'feel vibration' induced by the LFN. Application: The psychological scale from our study can be applied in quantitative psychological measurement of LFN at home or industrial environment. In addition, it can also help design systems to block LFN to provide optimal conditions if used the study outcome, .i.e., the relations between physical and psychological responses of LFN.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.624-631
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• 2008

This study evaluates the impact of aircraft noise on people's health using the Todai health index(THI). A questionnaire survey was conducted in the vicinity of Gimpo International Airport in Seoul, South Korea, from August 8th to September 9th, 2005. The survey area was divided into three groups based on different aircraft noise levels : area (1) for $80{\sim}85$ WECPNL, area (2) for $75{\sim}80$ WECPNL and area (3) for less than 75 WECPNL. In each area, approximately 200 respondents were sampled. Twelve scale scores of THI are converted to dichotomous variables based on scale scores of 90 percentile value or 10 percentile value in the control group. Logistic regression analysis taking twelve scores converted as the dependent variables and WECPNL(area), age, gender as the independent variables is conducted. Significant dose-response relationships are found in the scale of MOUT, DEPR, NERV, LIFE. Factor analysis was carried out and 2 factors are extracted. Those two factors might be called the "somatic factor" and the "mental factor". The dose-response relationship between two factors and noise seems to be unclear. Unexpectedly the odds ratio of the menatl factor in area (2), where the noise exposure level is lower than that of the area (1), is the highest and the annoyance in this area is also higher than area (1).

• Smart Structures and Systems
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• v.19 no.1
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• pp.1-10
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• 2017

The operation of subway trains induces secondary structure-borne vibrations in the nearby underground spaces. The vibration, along with the associated noise, can cause annoyance and adverse physical, physiological, and psychological effects on humans in dense urban environments. Traditional tethered instruments restrict the rapid measurement and assessment on such vibration effect. This paper presents a novel approach for Wireless Smart Sensor (WSS)-based autonomous evaluation system for the subway train-induced vibrations. The system was implemented on a MEMSIC's Imote2 platform, using a SHM-H high-sensitivity accelerometer board stacked on top. A new embedded application VibrationLevelCalculation, which determines the International Organization for Standardization defined weighted acceleration level, was added into the Illinois Structural Health Monitoring Project Service Toolsuite. The system was verified in a large underground space, where a nearby subway station is a good source of ground excitation caused by the running subway trains. Using an on-board processor, each sensor calculated the distribution of vibration levels within the testing zone, and sent the distribution of vibration level by radio to display it on the central server. Also, the raw time-histories and frequency spectrum were retrieved from the WSS leaf nodes. Subsequently, spectral vibration levels in the one-third octave band, characterizing the vibrating influence of different frequency components on human bodies, was also calculated from each sensor node. Experimental validation demonstrates that the proposed system is efficient for autonomously evaluating the subway train-induced ambient vibration of underground spaces, and the system holds the potential of greatly reducing the laboring of dynamic field testing.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.9-17
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• 2009

Discomfort Glare from the artificial light sources is an important issue in assessment of lighting quality for healthy buildings. Glare, as a factor of the characteristics of brightness, which has been defined as the sensation produced by contrast and luminance within an entire field view, unfavorably influences the occupants who performs visual tasks. It may cause annoyance and discomfort by interruption of visibility. In the whole visual field, glare can be determined by effects of the position, the luminance and the size of the light source and brightness of the surroundings. Therefore, experimental equipment is required to maintain a constant visual lighting environment. Recent studies have been developed and used the instrument for glare sensation evaluation but the instruments showed some difficulties to verify the correlation of glare indicators. The instrument have been developed with reference to former studies. It is called the Glare Tester. This is consist of 2[m]-diameter vertical dome screen painted with white flat paint, and light sources installed inside the screen. These light sources can provide various range of brightness at any inner surface of the screen. 2 Glare light sources can provide the value of luminance within the range of $0{\sim}150,000[cd/m^2]$. Moreover, 12 light sources are used for background luminance and it can perform the value of luminance within the range of $0{\sim}350[cd/m^2]$. Several experiments have been conducted using this Glare Tester to evaluate the range of the visibility, the values of BCD and the glare sensation in lower and upper visual field.