• 음성과학
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• 제8권4호
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• pp.139-156
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• 2001

Speech intelligibility in patients with complete dentures is an important clinical problem depending on the material used. The objective of this study was to investigate the speech of two edentulous subjects fitted with a complete maxillary prosthesis made of two different palatal materials: chrome-cobalt alloy and acrylic resin. Three patients with complete dentures in the experiment group and ten people in the controls groups participated in the experiment. CSL, Visi-Pitch were used to measure speech characteristics. The test words consisted of a simple vowel /e/, meaningless three syllabic words containing fricative, affricated and stops sounds, and sustained fricative sounds /s/ and /$\int$/. The analysis speech parameters were vowel and lateral formants, VOT, sound durations, sound pressure level and fricative frequency. Data analysis was conducted by a series of paired T-test. The findings like the following: (1) Vowel formant one of patients with complete denture is higher than that of the control group (p<0.05), while lateral formant three of patients with complete denture is lower than that of the control group (p<0.0l). (2) Patients with complete denture produced lower speech intelligibility with low fricative frequency (/$\int$/) than control group (p<0.0). The speech intelligibility of patients with metal prosthesis was higher than that of those with resin prosthesis (p<0.05). (3) Fricative, lateral and stop sound durations of patients with complete denture were longer than those of the control group (p<0.01 and p<0.05), respectively. Total sound durations of patients with metal prosthesis were similar to that of the control group (p<0.05), while those with resin prosthesis had a shorter duration (p<0.01). This implied that those with metal prosthesis had higher speech intelligibility than those with resin prosthesis. (4) Patients with complete denture had higher sound pressure levels /t/ and /c/ than the control group (p<0.01). However, sound pressure levels for /c/ of patients with metal prosthesis or resin prosthesis was similar to the control group (p<0.05). (5) Patients with complete denture had higher fundamental frequency than the control group (p<0.01).

• 소음진동
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• 제8권6호
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• pp.1030-1036
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• 1998

When the lateral dimensions of a duct is larger than or comparable to the wavelengths of Interest, higher order modes propagate in the duct. These modes will be radiated and produce noise. A number of sensors and actuators for control of radiating noise from the duct have to be incorporated with the number of modes which one wants to control. These considerations motivated the present study that considers a control system which has less microphones and control sources than required. In this work, by theoretical analysis, the control performance of such a kind of system is investigated in terms of sound-field variables and control system variables. The possible maximum and minimum value. mean and variance of residual acoustic potential energy are derived for the set of primary sound fields.

• Journal of Forest and Environmental Science
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• 제12권1호
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• pp.13-25
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• 1996

최근의 사방사업(砂防事業)은 방재공간(防災空間)의 확보뿐 만 아니라 주변환경(周邊環境)에 잘 조화되고 생물자원(生物資源)이 풍부한 환경공간(環境空間)의 확보가 강조되고 있다. 일본에서도 이와같은 노력이 1990년대에 들어 활발히 진행되고 있으므로 우리나라의 사방사업의 참고가 될 수 있도록 일본의 친환경적(親環境的) 사방사업(砂防事業)에 대한 자료를 수집, 분석하였다. 구체적인 내용은 합리적인 수변환경(水邊環境) 조성(造成)과 친환경형(親環境型) 사방사업(砂防事業)이며, 친환경적(親環境的)인 사방사업(砂防事業)은 사방(砂防)댐, 유로공(流路工)과 호안공(護岸工), 어도(魚道) 및 수질보전공(水質保全工) 등에 대하여 정리하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.811-816
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• 2011

This study includes investigation on sound transmission phenomena through a structural panel including structural vibration and feedback control methodology to minimize the transmission. Focus is placed on finding the relation between vibration pattern and sound transmission, and on finding optimal sensor and actuator location. A simple analog feedback control circuit is designed and implemented to verify the approach.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.955-956
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• 2014

Active noise control is noise reduction method by generate anti-phase control signal for destructive interference of through control speaker. purpose of this paper is create a virtual control source at a using the DBAP(Distance Based Amplitude Panning) algorithm which is one of the three-dimensional sound reproduction method, and verified through the experimentally for noise control method through the virtual control source. We compared active noise method by using one control speaker with active noise control method by using DBAP algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1398-1403
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• 2003

In this paper, a simple method to design an MIMO sound field control system was proposed. The control system was designed to achieve 1) noise attenuation and 2) sound equalization by utilizing feedback and feedforward controllers. The method was based on partial model matching on frequency domain which only required measured frequency response data, or impulse response data in order to tune parameters of the controller. The proposed method was applied to a normal office room and results of experiment showed effectiveness of the proposed method.

• 한국소음진동공학회논문집
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• 제12권12호
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• pp.950-955
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• 2002

The coupled finite/boundary element method is used in numerical analysis for acoustic radiation from the vibration of rectangular composite plate which is simply supported. This analysis is validated using the Wallace equation for an isotropic plate. Active control of sound fields has been tarried out using 3 pairs of piezoelectric sensor/actuator and a pair of viscoelastic material by Passive constrained layer damping treatment. The results show that the optimal placement of piezoelectric sensor/actuator and VE patch is required to control the sound fields from a vibrating composite plate.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.611-614
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• 2005

The introduction of the sound based on the soundscape concept has the effect to offer comfortable sound environments at the public spaces by masking undesired ones and to identify the spaces. Sound installation, sound sculptor and the soundscape are used for these purpose, but the most important factors to be considered therein are to determine what kind of sounds to offer and how to adjust them to the changing circumstances. But, installing, maintaining and adjusting the soundscape system directly in the field will ensue numerous problems as well as high costs. And, even if it was epochal and novel when the soundscape is first installed at a space, new different sound environment is necessary to continue the effectiveness as time goes. Thus, this study aims at devising the instrument system that has the artificial intelligence, enables to remote control, with a great ease, numerous variables, reproduce most agreeable sound sources, and can produce the proper sound fit to the space automatically and spontaneously.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1297-1301
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• 2007

The Conventional noise control attempts to simply reduce the level of product noise. But it is very straight forward way that we have consider human perception on noise. Since human listening is very sensitive to sound. Evaluation of the sound quality of a Vacuum Cleaner is studied base on human sensibility engineering. In this paper, we choose two Vacuum Cleaners that are sold in Korea and reduced noise control. Comparison Method is used to evaluate noise and preference of Vacuum Cleaner by steps. The sound quality of Vacuum Cleaner noise is analyzed by employing the subjective evaluation and by representing them in terms of the objective quantities. Semantic Differential Method is used to study sound quality Evaluation. To analyze the sound quality of Vacuum Cleaner noise, consider the coefficients of correlation between sound metrics and subjective rating. The linear regression models were obtained for the subjective evaluation and sound quality metrics.

• 한국소음진동공학회논문집
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• 제20권12호
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• pp.1223-1228
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• 2010

The conventional noise control attempts to simply reduce the level of product noise. But it is very straight forward way that we have considered human perception on noise. Since human listening is very sensitive to sound. Evaluation of the sound quality of a vacuum cleaner is studied base on human sensibility engineering. In this paper, we choose six vacuum cleaners that are sold in Korea and reduced noise control. The sound quality of vacuum cleaner noise is analyzed by employing the subjective evaluation and by representing them in terms of the objective quantities. Semantic differential method is used to study sound quality Evaluation. To analyze the sound quality of vacuum cleaner noise, consider the coefficients of correlation between sound metrics and subjective rating. The linear regression models were obtained for the subjective evaluation and sound quality metrics.