• Proceedings of the KSPS conference
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• 2006.05a
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• pp.127-130
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• 2006

This paper suggests an algorithm that can estimate the direction of the sound source with three microphones arranged on a circle. The algorithm is robust to microphones' gains because it uses only the time differences between microphones. To make this possible, a cost function which normalizes the microphone's gains is utilized and a procedure to detect the rough position of the sound source is also proposed. Through our experiments, we obtained significant performance improvement compared with the energy-based localizer.

• The KIPS Transactions:PartB
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• v.14B no.4
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• pp.273-280
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• 2007

This paper presents a new 3D sound toolkit called $EVE-Sound^{TM}$ that consists of pre-processing tool for environment simplification preserving sound effect and 3D sound API for real-time rendering. It is designed so that it can allow users to interact with complex 3D virtual environments by audio-visual modalities. $EVE-Sound^{TM}$ toolkit would serve two different types of users: high-level programmers who need an easy-to-use sound API for developing realistic 3D audio-visually rendered applications, and the researchers in 3D sound field who need to experiment with or develop new algorithms while not wanting to re-write all the required code from scratch. An interactive virtual environment application is created with the sound engine constructed using $EVE-Sound^{TM}$ toolkit, and it shows the real-time audio-visual rendering performance and the applicability of proposed $EVE-Sound^{TM}$ for building interactive applications with complex 3D environments.

• Korean journal of communication and information
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• v.31
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• pp.85-111
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• 2005

This paper aims at dealing with the communication of Korean gong sound. It is based on 'music-spirit theory' of Han-Gi Choi and Mead's 'symbolic interactionism', and does this by interpreting the message of gong sound that is mentioned in Korean literature. The gong sound brings out the message of symbolizing evaporation of Korean people's joy and regrettable matters in the playing yard by regulating of breathing according to the steps. By the novel "Gong Sound" of Sun-Tae Moon Korean gong sound has a message of people's joy, anger, avarice, anxiety and sorrow. In Jeong-Rae Jo's novel "Arirang" the Korean Gong Sound includes a message of evaporation of people's regret and raises the national spirit during the Japanese Imperialism. By Jeong-Ja Yoo's collection of poems, "The sound of flower breathing carried by gong sound", the Korean gong sound carries a message of a roar of spirit and breathing of the spring flower. In conclusion, the Korean gong sound is a sublime sound of sky which carries the message of symbolizing evaporation of people's joy and regrettable matters through the sound communication in the open space, and awakes us to a method of breathing with sky.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.101-108
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• 2009

This study aims to design ergonomic warning sound that is not confusing and enhancing preference. Four factors of the warning sound represented as interval, chord, reverberation and pitch were selected as independent variables. And, perceived urgency, perceived criticality, degree of confusion and user preference are measured as dependent variables. An experiment was conducted in silent lab environment. Warning sounds were given in 90dB constantly to subjects through stereo speakers. A statistical analysis revealed that interval was significant for perceived urgency; also interval and chord were both effective for perceived criticality. Pitch, interval, chord and the interaction between pitch and chord were effective in degree of confusion, so were reverberation, the interaction between reverberation and pitch and the interaction between reverberation and chord for preference. This study characterized the situation under which warning sounds are required into three types in terms of urgency and criticality; and found the right warning sound that the subjects perceived to best represent the situation through the validation study. These findings are expected to help the designer choose the right warning sound according to the situational contexts in which such warning sounds are implemented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.911-916
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• 2001

Structural acoustic modification method based on the structural mobility analysis is applied to reduce the structure-borne noise radiated from hard disk drive system. Sound intensity techniques and ODS(Operational Deflection Shape) techniques are also used in order to provide the structural acoustic information for the mobility modification. The sound intensity is for the acoustic visualization of the noise source locations, and the ODS is for the visualization of the vibration pattern and its dynamic characteristics of the noise sources. Using visualization information of sound and vibration, local structural input mobility is reduced in the frequency band of interest by designing asymmetrical wave-stringer structure in the wave-number domain as well as frequency domain. The overall sound pressure level is reduced by 4dB and its controlled sound power radiated from the disk drive is proved to under 2.8Bel in idle-spinning mode and 3.1 Bel in random-seeking mode, which are the lowest noise levels in the hard disk drive industry.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1239-1242
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• 1998

In television stereo system, to produce a realistic sound effect is very difficult because the distance between stereo speakers is very narrow. Many signal processing methods of widening the sound image for spatial impression have been studied. One of the methods of widening the sound image is using the Precedence Effect by reflected sound. However, this method does not work effectively in lower frequencies because of directivity of a speaker. In this paper, we propose an effective method of expanding stereo image using Precedence Effect and Phase Shifting method to produce a whole band frequency sound expansion. In experiments, we confirm the usefulness of the proposed stereo sound image expansion system.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1231-1234
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• 1998

Many signal processing methods of widening the sound image for spatial impression have been studied. Most typical methods of widening the sound image are related to the phase shifting and precedence effect. However, these methods are not effective in center sound image. As listener's position moves from center to outside, the center sound image is shifted to the speaker. That is to say, the directional localization of center sound image is unstable. In this paper, we propose a television audio system including center speaker, and analyze the role of center speaker using theory of Makida and precedence effect. In experiments, we confirm the usefulness of the center speaker for the stability of center sound image.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2152-2155
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• 2003

Divine bell of king Songdok(3.663m of the height, 2.227m of the diameter, 18,900kg of the weight, 7.7-21.5mm of the thickness), known as the bell of Emille which has been molded in 771 year to the illustrious memory of King Songdok for 34 years is one of culture heritages in the world. Even though the appearance of bell is very beautiful, also the sound of bell was appeared miraculous characteristics of shaking the sky, earth and human. The bell of Emille caused by discontinuous sound in maintaining continuous, strongly emotional sound and moving the mind of human etc, is appeared the 'Macnorlee' phenomenon which having the discontinuous sound in maintaining continuous. So far, it has reasoned out the phenomenon of the bell of Emille. but it was first proved a realized a baby-boiling sound about the bell of Emille according to the comparison and analysis. In this study of bell, we proposed improvement and device of the wooden parts beating the bell why a baby-boiling sound was not heard well as before.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.170-177
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• 2003

This study is to analyze the influence of the Tsushima Warm Current (TWC) on the variation of sound speed in the southern part of the East Sea. Sound speed is calculated by method of Chen and Millero (1977:, based on the CTD data measured in June of 1996. Sound speed in the central part of the TWC is about $45ms^{-1}$ more fast than that in the other regions without the TWC. Sound speed minimum layer (SML) in the TWC region exists between loom and 341 m, while it exists between 260m and 290m in the non-TWC region. SML distributes along the path of TWC over continental shelf in the coastal waters of Japan.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.91-98
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• 2004

Human uses level difference and time difference to get space information. Therefore this paper shows that method to presume direction of sound source by time difference and to mark presumed position. The position means direction from geometrical center of sensors to the sound source. To get the time difference of microphones input level, we will be explained about arrangement of microphones which used for the sensor to take the sound signal. It is included distance among the 3 microphones and distance between microphones and sound source. Secondly, input signals are transmitted to CPU througth digital process. CPU is used to DSP(Digital Signal Processor) for manage the signal by real time. Finally, the position of sound source is perceived by an explained algorithm in this paper.