• 소음진동
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• 제10권1호
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• pp.49-56
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• 2000

In this paper performance of the noise barrier which is 53 m long and 6m high, and is located between the high rise apartment and road, is studied by using experimental and analytic method. The insertion loss is measured by using the direct method in accordance with the ISO code, while theoretical prediction is based on Muradali and Fyfe's method (Applied Acoustics, Vol. 53, 49~75, 1998). In addition to the diffraction at the top of the barrier, the waves are reflected infinite times between the building and the barrier, which is equivalent to replacing the building by the infinite series of the image receiver points. In two-dimensional study, the prediction of the insertion loss results in significantly overestimated values compared with the measurement. However three-dimensional analysis shows reasonable agreements, where traffic noise is assumed as incoherent line source and the length of the source is larger than that of the barrier.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.649-653
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• 2005

Recently, many membrane structure buildings are constructed with the trend of multi functional and high technological construction. The membrane structure has the characteristics such as distinguished architectural shape which can make variable space creation and can make economic use of material. Therefore, it is in the spotlight of sport complex, various concert hall, and public service buildings. However, the acoustic study of membrane structure has not been following up the increasing demand for the membrane structure. In this study, the acoustic characteristics of membrane structure will be studied and analyzed using architectural acoustic factors based on acoustic design theory And also, the differences between theoretical exhortation value and outcome of study will be studied with the basis of architectural acoustic material study.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.686-689
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• 2005

This study aims to analyzed the acoustics characteristics of Korean Traditional Houses in Chonnam Province varied with lay out and floor plane to reflect the way of control for environmental condition. These houses are surveyed the reverberation time and level difference between rooms of the main living room and other main floored room, master room and kitchen. As a result, the reverberation time of traditional rooms are below 0.6 second, and the sound insulation performance of Korean traditional door are mostly very low grade with D-15. The level difference between rooms are low grade not to meet minimum class except between main living room and master room away from main living building.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.25-32
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• 2005

In China, environmental noise policies are composed of correlated laws adopted by the Standing Committee of the National People's Congress and promulgated by the President of the country, regulations promulgated by the State Council and/or local government, standards issued by the Standardization Administration Committee (SAC) under the State Council. The laws mainly include the 'Environmental Protection Law' and the 'Law on Prevention and Control of Pollution From Environmental Noise' Regulations are often applied to a special noise pollution phenomenon of wide influence. They are generally only effective in a given area and/or a specific period. Tens of correlated standards specify the noise level limits of different functional zones of land use and of different equipment, machines, devices, appliances etc., and the measurement methods. In this presentation, a brief introduction to these policies and their operations is given and discussed. The conclusion is that the policies supply an effective legislative basis for environmental noise prevention and control in China, but still a lot of work should be conducted and completed to strive for a quiet society.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.910-915
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• 2001

For the environmental noises has various frequency spectrums and fluctuation characteristics. the dimensions of psychological influencing on persons IS also complex. Analyzing this complex-dimensional psychological factors and characteristics of them then developing the evaluation indexes which have a good correspondence are important for improvement of noise environment. To develop the effective evaluation procedures which reflect the psychological respects of persons, this study firstly we drove the psychological factors and classified the noises into several groups by their psychological response characteristics through the psycho-acoustical experiments using environmental noises. In addition, we analyzed the relationship between the various evaluation indexes, psychological factors and the noise groups, and then suggested several indexes for the simple and efficient psycho-acoustic evaluation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1093-1098
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• 2001

The interior sound pressure level of the Korean high speed train is predicted using ray acoustic method. The motor car, motorized car and passenger cabin are investigated under the environment of passing open countryside and inside tunnel Calculated sound levels of KHST are compared with the those of KTX prototype which vehicle shows similar acoustic behavior with KHST for the purpose of assuring the calculated data. In order to reduce the calculated SPL in systematic way, contribution analysis of sound sources and sensitivity analysis of concerning wall's transmission loss on the SPL of the designated receiving points are carried out. Finally, practical design suggestions are proposed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.482-485
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• 2004

On the basis of theoretical studies on the effect of the cylinders attached to semi-infinite screens, the tangential sound power-transport parallel to the surface of the attached cylinder is minimized by means of a secondary sound field, which is generated from a part of the attached cylinder. The numerical study shows the possibility of deflecting the incident sound by minimizing the acoustic surface impedance of the upper sections. The acoustical shadow region was more pronounced in both near- and far-field compared to the passive case with rigid surface, i.e. without active control. For a relatively wide frequency range it was possible to enhance shielding effects only with few secondary sources and error microphones. In this paper effects of some control parameters on the actively controlled sound field near the top edge of noise barriers are studied. Results of numerical study and model measurements are shown and discussed.

• 한국소음진동공학회논문집
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• 제17권3호
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• pp.201-206
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• 2007

It is important to consider the sound absorption characteristics of building interior decoration materials when we design a building and simulate acoustics in a room. The purpose of this study is to accumulate acoustic data on building interior decoration materials and give a basic data for improving the sound absorption performance by testing the sound absorption coefficients of 9 types of ceiling materials, 14 types of wall papers and 20 types of floor papers.

• Structural Engineering and Mechanics
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• 제74권3호
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• pp.425-434
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• 2020

The present paper is concerned at investigating the effect of hydrostatic initial stress, gravity and magnetic field in fiber-reinforced thermoelastic solid, with variable thermal conductivity. The formulation of the problem applied in the context of the three-phase-lag model, Green-Naghdi theory with energy dissipation, as well as coupled theory. The exact expressions of the considered variables by using state-space approaches are obtained. Comparisons are performed in the absence and presence of the magnetic field as well as gravity. Also, a comparison was made in the three theories in the absence and presence of variable thermal conductivity as well as hydrostatic initial stress. The study finds applications in composite engineering, geology, seismology, control system and acoustics, exploration of valuable materials beneath the earth's surface.

• 교육철학
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• 제66호
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• pp.77-103
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• 2018

This study focused on the meaning of 'educational philosophy' by the method of corpus analysis. There is the difference of meaning on educational philosophy between professional researchers and publics. This semantic phenomenon implies that the image acoustics of 'educational philosophy' are not matched between two groups. This study, which originated from Saussure's linguistics theory, examined the semantics of educational philosophy in the . Unlike philosophical inquiry on education, the definition of educational philosophy, the general public use 'educational philosophy' like the connotation of secret of successful learning and child nurturing. Given the power of the media and the mass, these tendency could affect the meaning and definition of educational philosophy. Professional researchers should investigate these acoustic image from the sense of linguistic and educational approaches. These researches could contribute to clarify descriptive and normative meaning of the educational philosophy.