• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.191-197
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• 2013

In this paper, we present the college curriculum for the acoustics and audio engineering on digital convergence environment. For these purposes, we categorized the colleges which linked on the ASA and AES websites into three types according to their characteristics such as an acoustics-oriented type, an applied-acoustics type, and a convergence-oriented type. And a basic step-by-step curriculum model for the audio acoustics is suggested based on the characteristics of the category analysis. The proposed model can be effectively used to build an acoustics and audio technology course at the domestic colleges.

• The Journal of the Acoustical Society of Korea
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• v.25 no.2
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• pp.72-77
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• 2006

British acoustics in the nineteenth century is important as a foundation for modern acoustics in the history of acoustics. The Purpose and objective of acoustics was different from those in modern age. and musical motivation was distinguished among them. This study intends to clarify various aspects of interaction between music and acoustics in nineteenth-century Britain by examining related materials in both published and unpublished forms. Then music Provided acoustics with instruments, subjects, and personnel, and acoustics did much as musical science in helping to improve and develop musical scales and enhancing the exactness of measurement of absolute pitches. Music played an essential role in developing acoustics to a modern discipline in Europe, especially in Britain. all through the nineteenth century.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.525-528
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• 2002

The speed of sound, transmission coefficient, and attenuation are measured around the center frequency 1 and 2 MHz in solid materials such as bone, sediment, rubber, and Lucite materials. Common and different characteristics of such materials in the sound speed, transmission coefficient, and attenuation are discussed. Ambiguities in estimating such acoustic characteristics we also addressed. Ultrasonic properties of the first and second kind waves are clarified for different materials. Discussions are concentrated on classes of sound speed, broadband ultrasonic attenuation (BUA), and correlations of sound speed and BUA with apparent density. New correlations of inverse sound speed square and BUA with apparent density are suggested.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.24-33
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• 2004

Recently, ship acoustics takes more important role in acoustic stealth and classification of underwater targets. In this paper, a theoretical concept is proposed for M＆S-based test and evaluation of ship acoustics. The concept is based on two different approaches: on Top-Down method which emphasizes the survivability of the ship and on Bottom-Up method which considers acoustic characteristics of the ship-equipments. In order to improve the effectiveness of M＆S-based T＆E for ship acoustics, it is recommended in this paper to compromise the two approaches as adequate.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.589-590
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• 2008

Sound absorption characteristics of audience seating is very important when design and simulate room acoustics of concert halls or multi-purpose auditoriums. Sound absorption characteristics of audience seats were measured in reverberation chamber by varying the row to row spacing and number of audiences. By the increment of the row to row spacing, sound absorption characteristics in mid frequency band was increased. Also, sound absorption was proportionated to the number of audience.

• Journal of Korean Association for Spatial Structures
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• v.8 no.3
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• pp.53-63
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• 2008

In this study, the reverberation characteristics of coupled spaces were investigated using a scale model. Two rooms were connected through an acoustically transparent opening known as an aperture. The acoustic characteristics of the coupled room by varying three parameters, the aperture opening size, the absorption ratio between the two rooms and the locations of the secondary room, were measured and analysed. The results indicated that a reverberant secondary room, produced large variations of the acoustics in the main room and an absorptive secondary room was effective to provide systematic control of the acoustics in the main room. The reverberant secondary room should be located at the rear of the stage and the aperture opening ratio over 6.25% produced large variations of the acoustics in the main room. However, the aperture opening ratio over 25% had no effect on variations of the acoustics in the main room. The absorptive secondary room should be located at the rear of the audience areas and the aperture opening ratio over 3.13% produced large variations of the acoustics in the main room.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.148-158
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• 2015

It is difficult to test a detection system in underwater acoustics channel environments. The system can be evaluated by using simulation analysis tool. In this paper, a simulation tool is proposed to analyze the effectiveness of underwater acoustics detection based on database for real environments. First, the underwater environment is built based on HYCOM underwater environment database. Then, a multipath characteristic is considered through calculating underwater acoustics propagation path/pressure based on the ray theory. Also, hydrophone thermal noise and underwater ambient noise are considered to reflect underwater noise characteristics.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.329-332
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• 2001

피아노 향판의 진동 특성은 피아노 음질을 결정짓는 매우 중요한 요소이다. 그런데 피아노를 제작함에 있어 브릿지를 향판에 부착함으로서 진동 특성이 브릿지 부착 전과 달라지게 된다. 본 연구에서는 브릿지가 부착되지 않은 피아노 향판의 진동 특성을 측정한 후 동일한 항판에 대하여 브릿지를 부착한 상태에서의 진동 특성을 클라드니 패턴을 이용하여 비교, 측정하였다. 두 경우에 대한 비교 측정 결과 저주파에 대해서는 진동 특성이 큰 차이를 보이지 않지만 고주파에 대한 진동 특성은 크게 달라짐을 확인할 수 있었다

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.5
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• pp.429-436
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• 2012

In concert halls and auditoriums, acoustic reflector and stage enclosure is one of the main factors on the room and stage acoustic characteristics. As a stage enclosure and acoustic reflector honey comb based light-weight reflector is widely used, because it is easy to install. However, there was not enough research on the surface density effect on room and stage acoustics. In this study, sound absorption coefficient tests on three kinds of wooden acoustic reflectors with different surface density were conducted. Surface density of acoustic reflector was changed from 11 kg/$m^2$ to 41 kg/$m^2$. For the low frequency excitation, sub-woofer was used with omnidirectional loud-speaker simultaneously. From the experiments, it was found that sound absorption coefficient below 250 Hz band was decrease by the increment of surface density. In order to check the influence of the surface density on room and stage acoustic parameters, room acoustic simulation was conducted with sound absorption coefficients, which were tested in reverberation chamber. By the increment of surface density of acoustic reflector, RT(reverberation time) and EDT(early decay time) were increased. Also, ST(stage support) was improved in low frequency bands.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1347-1351
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• 1987

This thesis aims at studying laplacian pyramid vector quantization which keeps a simple compression algorithm and stability against various kinds of image data. To this end, images are devied into two groups according to their statistical characteristics. At 0.860 bits/pixel and 0.360 bits/pixel respectively, laplacian pyramid vector quantization is compared to the existing spatial domain vector quantization and transform coding under the same condition in both objective and subjective value. The laplacian pyramid vector quantization is much more stable against the statistical characteristics of images than the existing vector quantization and transform coding.