• Earthquakes and Structures
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• v.7 no.6
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• pp.909-935
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• 2014

The seismic characteristics of two semi-gravity reinforced concrete cantilever retaining walls are examined via an experimental program using an outdoor shake table (one with and the other without concrete masonry sound wall on top). Both walls are backfilled with compacted soil and supported on flexible foundation in a steel soil container. The primary damages during both tests are associated with significant lateral displacements of the wall caused by lateral earth pressure; however, no collapse occurs during the tests. The pressure distribution behind the walls has a nonlinear trend and conventional methods such as Mononobe-Okabe are insufficient for accurate pressure estimation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.221-225
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• 2007

Recently, on account of stress relief and settlement of a healthy drinking culture, many people are visiting a song practice room. In case of such song practice room, since the mechanical voice through a loud accompaniment-music and microphone is on using, there has made a very loud noise, and it influences a lot to the adjacent other space and song practice room booth. Consequently, from the designing stage an efficient measures for soundproof and sound-insulation should be arranged. However, as most of the song practice room wall-bodies that already built up or under construction step were constructed merely with consideration on an interior-wise factor only, it is suffering at the soundproof and sound-insulation. Reflecting such viewpoint, this Study has measured Sound Transmission Loss on the subject for the song practice room wall-body recently built up, and based on the actually measured data, by practice of comparison?analysis on it using various evaluation methods, would intends to present a fundamental material for establishment an efficient sound-insulation measure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.969-973
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• 2007

The heavy-weight floor impact sound field of the receiving room in a testing building with bearing wall structure was investigated using bang machine and impact ball. The sound field was investigated through the impact sound pressure level distribution by the field measurement and computational analysis. Predicted sound field using the computational analysis agree with measurement result in the low frequency band. Result shows that standard deviations of the single number rating value are about 2dB in each impact source. Particularly, impact sound pressure level at 120cm height in 63Hz octave band was 5dB lower than spatial averaging value. It was found that receiving positions in the ministry of construction and transportation notice should be reconsidered.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.11
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• pp.1012-1019
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• 2013

Recently, awareness of noise is increased and high performance sound insulation performance wall is designed. But in spite of installing high performance sound insulation performance wall, sound insulation performance in space is reduced by door. In this study, Sound insulation performance of doors which commonly used in buildings was measured to analyze current situation in the field and effect of method which increase sound insulation performance is analyzed quantitatively. As a result, sound insulation performance of doors which commonly used in buildings is FSTC 17~29 and can be increased about 2~3 dB by install rubber seal or mohair.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.283-286
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• 2005

This study measures the levels of various receiving points for reducing deviations the floor impact sound. According to the results, 63-125Hz band appeals the large deviations. Among the spacial points, the spot of 0.75m from the wall correspond with the average of all spots. The KS stipulates that the receiving point should be off the wall more than 0.5m But obeying the rules, the large deviation appears. So, this study shows that the adequate receiving point is 0.75m from the wall.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.740-745
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• 1994

In the actual situation of measuring the environmental noise, it is very often that only the resultant phenomenon fluctuation contaminated by the additional noise of arbitrary distribution type can be observed. Furthermore, the observed data is usually given in a sound level form the purpose of estimating only the undisturbed objective output response, some estimation method is necessary to reasonably remove the effect of the above additional noise. In this paper, first, a mathematical model of arbitrary sound insulation systems is introduced in the form of a linear system on intensity scale, by using the well-known additive property of energy quantities. Next, some estimation method of the output response under the existence of background noise is derived. Then, based on the expression of the above estimation method, a new prediction method of only the output response probability function form for arbitrary sound insulation systems without. a background noise is proposed by use of observed data contaminated by a background noise. Finally, the effectiveness of the proposed method is confirmed experimentally too by applying it to the actual various type sound wall systems.

• The Journal of the Acoustical Society of Korea
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• v.24 no.4E
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• pp.139-143
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• 2005

The present study aims to investigate the effects of speaker location on the speech intelligibility in a classroom. In order to this, acoustic measurements were undertaken in a classroom with three different sound source locations such as center of front wall (FC), both sides of front wall (FS) and the center of ceiling (CC). SPL, RT, $D_{50}$, RASTI were measured in the 9 measurement points with same sound power level of sound source and MLS was used as the sound source signal. Also, subjective listening tests were carried out using Korean language listening materials which were recorded in an anechoic chamber. The recorded syllables were replayed and recorded again in the classroom with same sound source at three different locations and listening tests were undertaken to 20 respondents who were asked to write the correct syllables which were recorded in the classroom. The results show that higher sound intelligibility ($D_{50}$ of $47\%$, RASTI of 0.56) was obtained when sound source was located at the FS. The results also show that high sound intelligibility was obtained at the area nearby walls.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.104-109
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• 2002

The purpose of this study is to calculate transmission loss of KHST passenger vehicle's wall section accurately Typical transmission loss measurement of wall in the laboratory condition was carried out in advance, which is easier than KHST. Transmission loss results were compared with those by statistical acoustic method. Transmission loss values of KHST calculated by experimental method are compared with those from closed form solution.

• Journal of the Korea Institute of Building Construction
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• v.14 no.2
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• pp.143-149
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• 2014

Recently, the structure system for apartment buildings in Korea has been changing from wall to post-beam structure. This study examines the fire resistance and sound insulation of light-weight dried wall, a component of post-beam structure. For the fire resistance and sound insulation in Korea, the Compartment wall of apartment house in the case of building regulation has regulations specify the detailed requirement of fire compartment walls in apartment, but do not specify that of interior walls. This study proposes the fire resisting rate of the interior wall into three grades in which the highest grade requires fire resistance of 30 minutes and also proposes the requirement of sound insulation performance into three grades in which the lowest grade requires 35dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.488-492
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• 2007

Since Equipment-Noises occurring in machine room penetrate wall-body and travel to the adjacent room in the form of air-borne sound and structure-borne sound, it is appearing as the main factor that injures a peaceful residential environment, and due to this, such noise-damage is currently increasing rapidly. Consequently, despite the measures for sound-insulation and soundproof against the equipment-noise penetrated wall-body is urgently required, but as the subjective evaluation considered for psychological response about the equipment-noise was not practiced, many dissatisfactions are still raising even after some measure was taken. On such point of view, this Research, at the spot, has actually measured the equipment-noise that had permeated various wall-bodies, and examined its physical characteristics, thence based upon this, has conducted Psycho-Acoustics Experiment and investigated the interrelation between the physical evaluation value and psychological reaction value. It is considered that such study result could be utilized as the useful material at the time of establishment of the Grading Standard for the insulation performance against the Architectural Plumbing Noise, in the future.