• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.199-202
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• 2002

본 논문에서는 사람의 청각 모델을 기반으로 잡음에 의해 손상된 음성 신호로부터 잡음 신호의 마스킹 특성과 신호에너지의 지각(知覺)을 나타내는 임계대역(critical band)에서의 잡음 에너지에 대한 지각 패턴인 noise excitation pattern을 이용한 잡음 에너지 차감과 잡음 추정 오차에 의한 변형된 음성신호 내의 순음(tonal) 성분과 비순음(non-tonal)성분의 보정을 통해 효과적인 음성 품질의 개선을 위한 연구를 하였다.

• Journal of Navigation and Port Research
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• v.43 no.2
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• pp.110-121
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• 2019

Ports play a key role in international trade, as integral hubs where passengers and cargoes are loaded, discharged, and transshipped. However, the function of ports is becoming more diversified, expanding on roles as industrial clusters, as well as logistical centers. Such roles combined, reap numerous and significant benefits, mainly with growth of jobs and wealth creation, for the local population living in the city, and beyond. Citizens' awareness of the function and value of ports may not be positive, because of a range of negative factors such as emissions, noise, and road congestion, which can influence their perception. This study's contribution focuses on empirically evaluating the perception of Busan citizens of the local port, by applying Q methodology. The links connecting the port-city and local population, are assessed by identifying: 1) The level of awareness of the Busan citizens of the port; 2) Factors perceived as positive as well as factors perceived as negative by Busan citizens. There are four main factors, derived from the analysis: 1) Port functional knowledge; 2) Lack of social connectedness port-city; 3) Environmentally concerned and; 4) Absent port's ripple's effect. Policy recommendations suggest focusing on improving citizens' perception of the port, for each of the four main factors derived from the analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.311-317
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• 2007

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.4
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• pp.393-399
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• 2008

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• Journal of KSNVE
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• v.10 no.2
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• pp.254-260
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• 2000

the reduction of the interior nosie level has been the main interest of NVH engineers in the development of vehicles. However, the consumer's perception on the car noise is affected largely by the psychoacoustic characteristics of the noise, as well as the sound pressure level. In this study, the quality of the vehicle interior nosie is analyzed by employing the subjective evaluations and by representing them in temrs of the objective quantities. The subjective evaluatins were performed for the seven vehicles in the range of subcompact to luxury cars. The methods of paired comparisons and semantic differential were used to study the preference, the quality of interior noise and their correlation. The linear regression models were obtained for the subjective evaluation and the sound quality metrics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.511-516
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• 2002

Pitch is a perception related to the subjective frequency that is one of the psychological aspects or attributes of tones. It is also an important factor to determine the sound quality together with loudness and timber. Although the study on pitch has been active in the field of speech communication, but its application to the product sound quality is not yet enough. In this study, the empirical data by Zwicker is made use in the modification of the currently available pitch extraction model based on the place theory. By applying this modified model to various sound samples composed of tonal or banded components, the applicability of the model is suggested. As a demonstration example, the algorithm is used for the sound quality analysis of a product noise having fundamental frequency and harmonics. The result shows that the pitch should be regarded as an important subjective cue in the sound quality analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.586-591
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• 2002

Recently, the research and discussion to set up the evaluation standard for nor impact noises in multistory residential buildings has been vividly carried out In Korea. Therefore, the correlation between the methods and auditory responses was investigated through this research to investigate the applicability of the L index evaluation method and the reverse A characteristics evaluation method that are listed in JIS A 1419 since Japanese circumstance are similar to Korean after evaluating the duality of Korean multistory residential buildings. As a result, it was found that the correlation between the value resulted from L index evaluation and the value from reverse A characteristics evaluation is high. In addition, it was also revealed that human responses to each Impacter was similar. Consequently, it is considered th:31 the tendency about the two methods would be similar.

• Speech Sciences
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• v.6
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• pp.197-217
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• 1999

In a noisy class, the acoustic-phonetic features of the teacher and the perceptual features of learners are changed comparison with a quiet environment. Acoustical analyses were carried out on a set of French monosyllables consisting of 17 consonants and three vowel /a, e, i/, produced by 1 male speaker talking in quiet and in 50, 60 and 70 dB SPL of masking noise on headphone. The results of the acoustic analyses showed consistent differences in energy and formant center frequency amplitude of consonants and vowels, $F_1$ frequency of vowel and duration of voiceless stops suggesting the increase of vocal effort. The perceptual experiments in which 18 undergraduate female students learning French served as the subjects, were conducted in quiet and in 50, 60 dB of masking noise. The identification scores on consonants were higher in Lombard speech than in normal speech, suggesting that the speaker's vocal effort is useful to overcome the masking effect of noise. And, with increased noise level, the perceptual response to the French consonants given had a tendency to be complex and the subjective reaction score on the noise using the vocabulary representative of 'unpleasant' sensation to be higher. And, in the point of view on the L2(second language) acquisition, the influence of L1 (first language) on L2 examined in the perceptual result supports the interference theory.

• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.627-636
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• 2023

Due to the COVID-19 pandemic, the global population has experienced drastic changes, one of which is the increase in remote work. Given the ongoing possibility of exposure to infectious diseases and various other circumstances, the expansion of remote work is anticipated. To enhance the efficiency of remote work and address its existing limitations, this study surveyed the perceptions of indoor environments among individuals who worked from home during the COVID-19 pandemic. The study examined how the characteristics of individuals influenced their perceptions of indoor environments. It was found that the number of occupants and rooms, size of the house, and noise sensitivity affected the perceptions of outdoor noise, neighbor noise, and indoor noise caused by cohabitants. The findings can be used as foundational data for designing multipurpose housing that can be utilized not only for residential purposes but also for work and educational settings in the future.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.175-187
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• 1999

To investigate the risk perception of environmental issues, two consequtive surveys were conducted to environmental professionals using a standardized questionnaire from September to October in 1999. The number of subjects were 72 for the first survey and 68 for the second one. The questionnaire was consisted of items such as the degree of environmental pollution in Korea, risk perception of some issues on human health and ecosystem, and seriousness of the problems in the real situation in Korea. For the degree of environmental pollution in Korea, the average risk rating in the second test (7.4 point) was significantly higher than that in the first test (7.2 point). The risk perception on the general human health and ecosystem, and the seriousness in Korea situation were analyzed in the order of ′air pollution′, ′water pollution′,′soil contamination′,′waste′,′toxic chemical pollutants′,′food contamination′,′ocean contamination′, ′odor pollution′, and ′noise pollution′. Also ′toxic chemical pollutants′ problem was perceived to be the highest risk on general human health or ecosystem, and on present situation in Korea. ′Automotive vehicle exhaust′ problem was perceived to be the most severe environmental problems among specific 30 items. ′Industrial source air pollution′,′toxic air pollutants′, and ′domestic and industrial source pollutants to surface water′ were relatively severe environmental problems comparing to other problems. The pollution issues were classified into four categories by two aspects of perception; risk in general setting and seriousness in Korea situation. If the issues were highly serious in Korea and low risk perception in general setting then it is named "the Korea-specific group". Those that were all high score in two aspects, named "the Common group". Those that were all low in two aspects, named "the Nonsignificant group". And the issues were high risk perception in general setting and low seriousness in Korean situation, named "the Latent group".