• 감성과학
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• 제4권2호
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• pp.79-88
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• 2001

본 연구는 청각적 감성을 만족시키는 의류소재의 개발을 위해 직물 마찰음에 따른 생리반응 측정 및 심리적·주관적 평가를 통해 감성을 측정하여 이들이 음향특성과 갖는 관련성을 밝히고, 또한 심리생리적 반응 간의 상호 관련성을 파악하고자 하였다. 이를 위해 직물 마찰음의 음향특성으로서 LPT, ΔL, Δf, loudness[Z], sharpness[Z]를 계산하였고, 직물 마찰음에 대한 감각·감성 표현어(부드러움, 시끄러움, 유쾌함, 날카로움, 맑음, 거침, 높음)를 이용하여 주관적 평가를 실시하였으며, 생리적 반응으로서 뇌파, 혈류량, 심박변화율, 피부전도수준 등을 측정하였다. 주관적 감각·감성은 대부분 직물소리의 크기와 관련이 깊은 것으로 나타나, loudness(Z)와 총음압 LPT가 증가할수록 시끄럽고 거칠며 딱딱하고 불쾌하며 탁하다고 지각하였다. 또한 LPT는 혈류량의 감소에, loudness(Z)는 피부전도수준의 증가에 각각 영향을 미치며, sharpness(Z)가 높고 ΔL이 작을수록 LF/HF는 증가하는 것으로 나타났다. 심리생리적 반응간의 관련성은 부드럽고 조용하며 맑다고 지각할수록 slow alpha파가 증가하였고, 유쾌하고 매끄럽다고 평가할수록 혈류량은 증가하였다. 또한, 높다고 지각하는 소리에 대해 LF/HF는 증가하였다. 따라서, 직물 마찰음의 특성에 따라 심리생리적 반응에 영향을 미치는 것으로 나타났다.

• 한국소음진동공학회논문집
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• 제17권3호
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• pp.241-248
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• 2007

A study has been conducted to investigate the subjective responses of loudness and annoyance according to the exposed time of urban traffic noise in controlled laboratory environment. To make a closer inspection into psychological response relevant to noise characteristics while varying the time of exposure to noise, the subjects were presented a set of noises with different exposed time and requested to judge spontaneously on a 100-unipolar scale. To be concrete, the subjects were exposed to noises being varied in time from 15 sec up to max. 1,200 sec for the controlled traffic noise sources. So far achieved from laborious tests, it has an importance being on the logarithmic relations of perceived loudness and exposed time, say, it is more increased the perceived loudness in the sorter exposed time than in the longer exposed time. However, the trend is said to be not effective for the case of annoyance. On the other hand, the subjective impressions on relative annoyance of noise is shown to be correlated with the noise characteristics such as loudness (sones), tonality and time with logarithmic scale, the product correlation moment being calculated as $R^{2}=0.99$. The variances to be explained for annoyance assessments through varying the time of exposure were ranged between 30 % and 50% for the exposed time, $27{\sim}37%$ for tonality, and $34{\sim}20%$ for loudness, respectively With these results, hopefully, it can be helpful for those who want to work out an experimental design for evaluating an environmental noise or to quantify any psychological dimensions found in annoyance assessments.

• Fibers and Polymers
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• 제4권4호
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• pp.199-203
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• 2003

In order to investigate the effects of cross-sectional shapes on the sound characteristics of polyester fibers, 10 specimens were woven into a twill structure made of round, hollow, triangular, u-shape, cruciform, and composite cross-sectional (▲/▲ ,()/▲, Y/Y) fibers. Their rustling sounds were recorded, and their sound spectra were obtained from FFT analysis. Physical sound parameters (LPT, ΔL, Δf) and Zwicker's psychoacoustic parameters of the loudness(Z), sharpness(Z), roughness(Z), and fluctuation strength(Z) were calculated from the sound spectra. According to noncircular cross-section fibers, the hollow shaped fiber had the highest value of LPT, ΔL, loudness(Z), and fluctuation strength(Z). The triangular shaped fiber had a lower value of LPT, ΔL, loudness(Z), and roughness(Z) than those of the round shaped fiber. Among composite cross-section fibers, C1(▲/▲) and C3 (Y/Y) had higher values of LPT, ΔL, Δf and loudness(Z) but C2(()/▲) had lower values. Also the LPT, ΔL, sharpness(Z), and roughness(Z) values of different denier were similar to each other, but the Δf and loudness(Z) values increased as the denier increased.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.279-284
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• 2011

The calculation of Zwicker's loudness which is needed for multiple frequency response with a fine frequency resolution using the finite element (FE) procedure usually requires significant computation time since a numerical solution must be obtained for each considered frequency. Furthermore, if the analysis is the basis for an iterative optimization procedure this approach imposes high computational cost. In this work, we present an efficient approach for obtaining Zwicker's loudness via the Pad$\acute{e}$ approximants and applying in an acoustical topology optimization procedure. The paper is focused on an efficient and accurate calculation of Zwicker's loudness, design sensitivity analysis, and the acoustical topology optimization method by using Pad$\acute{e}$ approximants. The paper compares the efficient algorithm to results obtained by a standard FEM. Comparison are made both in terms of accuracy and in terms of CPU-times needed for the calculation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.330-330
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• 2007

• Journal of Chest Surgery
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• 제22권4호
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• pp.589-593
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• 1989

The frequency spectrum of the metallic closing sound and its loudness were measured by non invasive techniques in 66 patients. They had examined a total of 7 Carbomedics valve, 10 Duromedics valve, 11 St. Jude heart valve in mitral position and 8 Carbomedics, 10 Duromedics, 20 St. Jude heart valve prostheses functioning normally in aortic position. Statistical comparison of the loudness from sound produced by the three valves in each position, the following; The Carbomedics valve has the lowest average loudness, followed by the St. Jude medical valve, and finally the Edward Duromedics valve. And we analysis the changing factor of the loudness of valve sound, only the velocity of the flow through the valve influenced to the valve sound.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.137-140
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• 2007

A prediction model for the sound quality of household refrigerator noise was proposed by investigating subjective and objective attributes of the noise [Jeon et al. (2007) Appl. Acoust.]. In the present study, the just noticeable difference (JND) of each sound quality metric - Zwicker's loudness, sharpness, roughness and fluctuation strength - which constitute the prediction model was investigated. Loudness of recorded sound samples from five refrigerators were varied according to constant intervals in sound pressure levels. Sharpness was also changed at 14-16 barks. Auditory experiments were conducted to discriminate the JNDs of loudness and sharpness by method of limit. The results indicated that JNDs of loudness and sharpness were 0.50 sone and 0.08 acum, respectively.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.121-123
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• 1995

This paper presents a new method which compensates loss of loudness for digital hearing aids. Loudness grows more rapidly in frequency domain with substantial shifts of hearing threshold, so that loud sounds reach the uncomfortable sound level (UCL) at about the same physical stimulus level as with normal hearing. The result is a compression of the available dynamic range of hearing. Many techniques have been developed to compensate for hearing losses. In this paper, we propose a digital hearing aid which uses a single digital filter for reducing distortion and the fuzzy function to calculate gain factors. This function describes how much gain is needed for every frequency to restore loudness perception of a normal ear.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.374-385
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• 2012

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.

• 대한전자공학회논문지
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• 제20권6호
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• pp.58-61
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• 1983

본 연구는 피이드백형 음량조절 회로와 이것에 결합한 음향재생 증폭기에 사용되는 라우드니스 제어회로에 관한 것이다. 재생 음계 레벨에 따라 변화하는 라우드니스 보상곡선에 추종하는 특성을 갖도록 브리지 트윈 T회로망과 피이드백 회로에 삽입한 석통의 음량조절용 가변저항기로 라우드니스 제어회로를 구성하였다. 이 새로운 방식에 의한 라우드니스 제어회로를 실현하여 그 특성을 측정하고 또 컴퓨터 시뮬레이션한 것을 비교한 결과 이상에 가까운 보상특성을 얻었다.