• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1075-1079
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• 2002

This paper presents a result of sound transmitting system with power line communication technique, Sound transmitting system is a transmitter which transmits modulated audio signal to power to power line and receiver which is capable of detesting it with earphone or speaker. It has been evaluated with the frequency characteristics and spectrum analysis. And, from the result of evaluation on the developed system, we confirm the superior sound transmitting characteristics, and the possibility of application on a language laboratory.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.128-134
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• 2004

This paper presents a result of sound transmitting system with power line communication technique. Sound transmitting system is a transmitter which transmits modulated audio signal to power to power line and receiver which is capable of detecting it with earphone or speaker. It has been evaluated with the frequency characteristics and spectrum analysis. And, from the result of evaluation on the developed system, we confirmed the superior sound transmitting characteristics, and the possibility of application on a language laboratory.

• Journal of the Korean Institute of Oriental Medical Informatics
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• v.14 no.2
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• pp.1-9
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• 2008

With the booming complementary medicine as a social trend of well-being, treatment by the sound waves of six kinds of syllables is believed to restore that healthy balance to the body. Sound therapy refers to a range of therapies in which sound is used to treat physical and mental conditions. Healing is done by transmitting beneficial sound to the affected area related to five viscera and six bowels. The healing sound may be produced by a voice. sound wave vibrations are to treat physical and mental conditions. In general, this therapy is based on the theory that all of life vibrates, including people's bodies. When a person's healthy resonant frequency is out of balance, physical and emotional health is affected. When a person's healthy resonant frequency is out of balance, physical and emotional health is affected. This paper focuses on the sound therapy by six syllables of 'hyu', 'huo', 'ho', 'sa', 'chi' and 'hui'.

• Journal of Multimedia Information System
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• v.8 no.1
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• pp.11-16
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• 2021

This study developed a design to estimate the location of rescue demander using the sound system at disaster site, in the conditions of indoor positioning cannot be performed properly. It is a location tracing system through smart phone application. It generates sound wave information of rescuer at the rescue site, and it can be used as assistant means for indoor location tracing at the disaster site using sound wave receiving measurement technology.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.806-814
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• 2009

This paper reviews a study about sound reflection control using an active sound absorber. An active sound absorber includes sound transmitting and receiving piezocomposite sensor layers molded by water tight epoxy, and connected with a feedback controller. The multi-layer sensors and the controller consists a closed feedback loop, whose intrinsic characteristics shows excellent impedance matching performance within specified frequency band, and consequently, minimizes reflection waves. Multilayer sound transmission model is derived based on one dimensional model, and its performance is verified with experiment using a pulse tube setup.

• The Journal of the Acoustical Society of Korea
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• v.31 no.2
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• pp.73-78
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• 2012

The photophone, Alexander Graham Bell's device for transmitting sound through light was patented in 1880. It included the transmitter modulating and reflecting strong light like sunlight to a distant receiver which produced sound. In this working of the photophone, the discovery of the sound-emitting effect under illumination was very essential. Longing for being famous in the scientific community, Bell focused on presenting various methods for producing sounds and for maximizing the loudness by performing intensive research on the photoacoustic effect. Bell's scientific research on photoacoustics was successful in establishing himself as a scientist and laid a foundation of photoacoustic analysis. And his invention became a basis for other researchers' subsequent technologies like fiber-optic communication.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.701-705
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• 2007

The equipment noise of machine room that generates at the building where human-being is living, is becoming to an object of strong civil appeal, and because it influences to the residential space through the floor or wall, its damage is very serious level. Accordingly, while an efficient forming of the sound insulating measures is earnest, as most of the transmission loss data was the material measured in laboratory, in case when it was applied to the job site, due to the precision difference of constructing work and the influence of detoured transmitting sound, the case of disaccord is the most. Therefore, this thesis has intended to present a fundamental data for an efficient establishment of sound insulation measure, by means of comparison analysis with the existing transmission loss data, after measurement of the transmission loss on the object of various walls, at the construction equipment machinery room.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.480-485
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• 2002

The overall noise reduction was compared in regard to the vibrational characteristics of floor impact noise in a multi story residential building which has several noise reduction treatments. The vibration through its structural elements such as wall, floor and ceiling and sound emitting were investigated for each insulation treatment. It was found that, in case of heavy-weight impact noise, the vibration energy is emitted mostly from ceiling, but for the light-weight impact noise, most of the energy comes through ceiling and walls. That is, the vibration of a ceiling is the main factor that determines the frequency characteristics of the transmitting noise to lower floors.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.1
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• pp.27-34
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• 2016

The type of ultrasound transducer used influences the quality of a reconstructed ultrasound image. This study analyzed the effect of transducer type on ultrasound computed tomography (UCT) image quality. The UCT was modeled in an ultrasound simulator by using a 5 cm anatomy model and a ring-shape 5 MHz 128 transducer array, which considered attenuation, refraction, and reflection. Speed-of-sound images were reconstructed by the Radon transform as the UCT image modality. Acoustic impedance images were also reconstructed by the delay-and-sum (DAS) method, which considered the speed of sound information. To determine the optimal combination of transducers in observation, point-source, flat, and focused transducers were tested in combination as trasmitters and receivers; UCT images were constructed from each combination. The combination of point-source/flat transducer as transmitting and receiving devices presented the best reconstructed image quality. In UCT implementation, the combination of a flat transducer for transmitting and a point transducer for receiving permitted acceptable image quality.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.656-659
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• 2017

In this paper, we propose a digital method for transmitting audio signals using LED visible light communication system. In the proposed method, we compare the method for transmitting audio signal in analog signal and the method for transmitting by digital signal. When amplifying the audio sound and transmitting the analog signal using the LED visible light communication, attenuation corresponding to the transmission distance occurs, and there is a disadvantage that it is noisy. In order to overcome this, we propose a method for transmitting digital audio signals. The proposed method has the advantage of reducing the influence of noise, but it turned out that it is affected much by the LED blinking speed. Various methods to overcome this need to be continuously studied.