• Annual Conference of KIPS
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• 2000.10a
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• pp.711-714
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• 2000

가상현실은 현실에 구애받지 않고 상상의 세계를 현실과 같이 만들어 내어 인체의 모든 감각기관이 인위적으로 창조된 세계에 몰입됨으로써 현실에 있는 것처럼 느낄 수 있는 사이버스페이스이다. 본 논문에서는 청취자의 머리움직임에 따라 머리 추적기로부터 수신된 정보로서 음향의 방향감 간의 상관모델을 구성하여 시스템내의 S/W 모듈에 전달하는 인터페이스와 이를 토대로 머리 움직임 변화에 부합되는 실감음향을 생성하고, 영상도 함께 동기화하여 몰입감을 증대시키는 실감음향 인터페이스에 대해서 논의한다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.2
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• pp.199-207
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• 2008

A hybrid technique that combines the advantages of binaural reproduction and sound field reproduction technique is proposed. The concept of HRTF-field, which is defined as the set of HRTFs corresponding to the various head dislocations, enables us to realize virtual source imaging over a wide area. Conventional binaural($2{\times}2$) reproduction system is redefined as a MIMO system composed of multiple control sources and multiple head locations, and HRTF variations corresponding to various head movement are quantified. Through the direct control of HRTF-field, reproduction error induced by head dislocation can be minimized in least-square-error sense, and consequential disturbances on the virtual source image can be reduced within a selected area. Simple lateralization examples are investigated, and the reproduction error of the proposed technique is compared to that of higher-order Ambisonics.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.506-515
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• 2023

This study is to find a method to learn engine sound after the start-up of a diesel generator installed in nuclear power plant with an unsupervised deep learning algorithm (CNN autoencoder) and a new method to predict the failure of a diesel generator using it. In order to learn the sound of a diesel generator with a deep learning algorithm, sound data recorded before and after the start-up of two diesel generators was used. The sound data of 20 min and 2 h were cut into 7 s, and the split sound was converted into a spectrogram image. 1200 and 7200 spectrogram images were created from sound data of 20 min and 2 h, respectively. Using two different deep learning algorithms (CNN autoencoder and binary classification), it was investigated whether the diesel generator post-start sounds were learned as normal. It was possible to accurately determine the post-start sounds as normal and the pre-start sounds as abnormal. It was also confirmed that the deep learning algorithm could detect the virtual abnormal sounds created by mixing the unusual sounds with the post-start sounds. This study showed that the unsupervised anomaly detection algorithm has a good accuracy increased about 3% with comparing to the binary classification algorithm.

• The Journal of the Acoustical Society of Korea
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• v.27 no.4
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• pp.207-214
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• 2008

To create 3D sound, we usually use two methods which are two channels or multichannel sound systems. Because of cost and space problems, we prefer two channel sound system to multi-channel. Using a headphone or two speakers, the most typical method to create 3D sound effects is a technology of head related transfer function (HRTF) which contains the information that sound arrives from a sound source to the ears of the listener. But it causes a problem to localize a sound source around a certain places which is called cone-of-confusion. In this paper, we proposed the new algorithm to reduce the confusion of sound image localization. HRTF grouping and psychoacoustics theory are used to boost the spectral cue with spectrum difference among each directions. Informal listening tests show that the proposed method improves the front-back sound localization characteristics much better than conventional methods.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.299-307
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• 2020

Since 1964, research and improvement projects on Gugak instruments have been carried out to modernize, standardize, and scientificize them, but their inherent problems of Gugak instruments have failed to produce significant results. It seems that one of the main reasons for this is that the study of instrumental acoustics on Korean traditional instruments was not preceded. In Gugak orchestra, Sogeum used in concertos and solo music is a musical instrument that plays the similar role in Western orchestras due to its clear tone and high sound range. In this paper, the sound colors of Sogeum and flute, which sound similar, were analyzed through the their harmonics distribution and sound structures of the instruments. This showed that the overall tone was richer and softer than Sogeum, and that the tones of the two instruments sounded similar due to the similar composition of harmonics. In the future, it is hoped that musical instrument acoustical researches on various Gugak instruments will continue to help popularize and globalize Gugak instruments.

• Journal of the Korea Society of Computer and Information
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• v.29 no.10
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• pp.157-164
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• 2024

In this paper, we propose a technique that utilizes the physical properties of foam particles to synthesize foam sounds and efficiently control their size. A typical way to represent sound in physics-based simulation environments is to generate and synthesize virtual sounds. In particular, foam particles have a large number of particles, so synthesizing sounds using only particles is computationally expensive, and a way to reduce the amount of computation is to use spatial information, lattices. In this paper, we present a method for reliably mapping and clustering foam particles into a lattice space. Furthermore, we utilize this structure to control the loudness of the sound according to the location of the sound source and the audience. As a result, the method proposed in this paper proposes an efficient way to synthesize the sound of bubble particles, which utilizes the velocity and position of the bubble particles projected in the lattice space, and synthesizes the sound of bubble particles based on the position relationship of the audience and the directionality of the sound.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.722-725
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• 2006

Studies on the ways to construct agreeable sound-amenity have been processed in Korea recently and Virtual Acoustics Field Simulation System (VAFSS) which is an active acoustics reproducing system has been made as a technique to realize the results of the study. This system catches the changes of surroundings and produce sounds which go well with the mood of the space. The fact that a man thinks a sound goes well with factors of the environment should be an individual evaluation. Thus, the standards to classify factors influencing the preference of the sound, which can be judged by the environment, are needed. This study suggests the standards of factors to provide agreeable sound for people according to changes of the time and other elements. Among the factors influencing environment, the temperature, the humidity and the wind were suggested as standards of discomfort Index and wind chin temperature. Besides, only the intensity of illumination has been chosen to estimate the intensity of radiation as a part of factors of the whether.

• Journal of Broadcast Engineering
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• v.28 no.2
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• pp.213-229
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• 2023

In this paper, we introduce a spatial sound rendering system that provides 6DoF spatial sound in real time in response to the movement of a listener located in a virtual environment. This system was implemented using MPEG-I AEP as a development environment for the CfP response of MPEG-I Immersive Audio and consists of an encoder and a renderer including a decoder. The encoder serves to offline encode metadata such as the spatial audio parameters of the virtual space scene included in EIF and the directivity information of the sound source provided in the SOFA file and deliver them to the bitstream. The renderer receives the transmitted bitstream and performs 6DoF spatial sound rendering in real time according to the position of the listener. The main spatial sound processing technologies applied to the rendering system include sound source effect and obstacle effect, and other ones for the system processing include Doppler effect, sound field effect and etc. The results of self-subjective evaluation of the developed system are introduced.

• Journal of the Korean housing association
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• v.19 no.4
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• pp.49-57
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• 2008

The case study for this research is a middle school music room located in Iksan City, Korea. Although the room is used for teaching music, indiscreet sound-absorbing materials were applied within the space. Accordingly, a number of difficulties have been experienced when using the room. During a music lesson, the sound-volume is inadequate for music appreciation, while the music performance has an arid sound due to an insufficient echo. In order to control the obstructive factors resulting from a short Reverberation Time, the acoustic factor is optimized in this study by using an Acoustic Simulation, following an arrangement of Acoustic Design. A Psycho-acoustics Experiment was conducted using the Auralizational Technique, whereby the Virtual Acoustic Field can be experienced at the design stage.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.157-160
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• 1999

지금까지 가상 현실 또는 가상 환경에 관한 많은 연구가 있었지만 그 대부분이 시각적 효과에 관한 연구에 치우쳐 있었다. 그 결과로 3D 그래픽등 시각적 효과에 관한 부분은 상당한 수준에 올라 있으나 청각적, 음향적 부분은 아직도 발전 정도가 상대적으로 낮다. 가상 현실을 위한 음향은 크게 HRTF등을 이용한 음상 정위와, 음장 재현으로 나눌 수 있다. 본 논문에서는 가상 현실 체험자의 이동에 따라 효과적으로 음장을 재현하는 방법에 대해 논하고자 한다. 본 논문에서 제안하는 시스템은 크게 전처리 부분과 실시간 처리 부분으로 구성되어 있으며 전처리 과정에서 음장을 계산하여 실시간 처리 부분에서 체험자의 위치를 추적하여 음장을 재현한다.