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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society for Noise and Vibration Engineering
Journal Basic Information
Journal DOI :
The Korean Society for Noise and Vibration Engineering
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Volume & Issues
Volume 16, Issue 12 - Dec 2006
Volume 16, Issue 11 - Nov 2006
Volume 16, Issue 10 - Oct 2006
Volume 16, Issue 9 - Sep 2006
Volume 16, Issue 8 - Aug 2006
Volume 16, Issue 7 - Jul 2006
Volume 16, Issue 6 - Jun 2006
Volume 16, Issue 5 - May 2006
Volume 16, Issue 4 - Apr 2006
Volume 16, Issue 3 - Mar 2006
Volume 16, Issue 2 - Feb 2006
Volume 16, Issue 1 - Jan 2006
Selecting the target year
Application of Taguchi Method to Robust Design of Acoustic Performance in Mobile Phones
Hwang, Gun-Yong ; Hwang, Sang-Moon ; Kwon, Joong-Hak ; Kim, Kwang-Seok ; Lee, Hong-Joo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 997~1004
DOI : 10.5050/KSNVN.2006.16.10.997
With the growth in electronics and the remarkable advance in wireless communication technology, mobile devices, such as mobile phones and PDAs are incessantly improved in their diverse functional performance. Lighter weight and smaller size has been gradually accomplished by recent circuit integration technology resulting in rapid growth in the number of mobile phone subscribers. Driven by customer demand, recent mobile devices are fully capable of realizing a variety of dazzling multimedia effects powered by electro-acoustic parts that have become one of the generic components. However, This paper also presents an oval micro-speaker, that is' expected to show an excellent performance within limited space of mobile phone, and its performance design has been suggested as well. Finally, a statistical approach to achieve high characteristic and performance is suggested by Taguchi method to identify a certain relationship between a mobile phone and a micro-speaker.
A Combined Rating System for Multiple Noises in Residential Buildings
Ryu, Jong-Kwan ; Jeon, Jin-Yong ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1005~1013
DOI : 10.5050/KSNVN.2006.16.10.1005
A survey and auditory experiment on multiple residential noises such as floor impact, airborne, bathroom, drainage and traffic noises were conducted to develop a combined rating system and to establish criteria for multiple residential noises. Subjective reactions such as annoyance, activity disturbance, sleep disturbance, and satisfaction to overall noise environment and each residential noise were recorded. The effect of individual noise perception on the evaluation of the overall noise environment was also investigated. The survey results showed that satisfaction for floor impact noise most greatly affects the overall satisfaction for overall noise environment and annoyance most greatly affects the satisfaction for individual noise sources. Auditory experiments were undertaken to determine the percent satisfaction for individual noise levels. Result of auditory experiment showed that the noise level corresponding to 40 % satisfaction is 49 dB
for floor impact and is about 40 dB(A) for airborne, drainage and traffic noise. From the results of the survey and the auditory experiments, an equation for predicting the overall satisfaction for multiple noises was developed and a classification of multiple residential noises was proposed.
An Experimental Study on the Noise Evaluation of H.D. TV sets by Psycho-acoustic Experiments
Lee, Ju-Yeob ; Lee, Tai-Gang ; Kim, Hye-Jin ; Kim, Sun-Woo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1014~1023
DOI : 10.5050/KSNVN.2006.16.10.1014
The purpose of this study is to propose the proper vocabularies for evaluating H.D TV set fan noise. To achieve this goal, psycho-acoustic experiments were carried out with TV set fan noise modulated at specific frequency band. Finally, a correlation analysis between vocabularies, and a factor analysis of psycho-acoustical responses were conducted. As a result of this study, followings are suggested. Analyzing the psycho-acoustical response corresponding to the various sound level, the higher the sound levels, the higher the response values were. It is estimated that the sound level determined psycho-acoustical responses. On the degree of response to fan noise, the initial level of negative feeling is located on
dB(A). The factor of evaluating H.D. TV set fan noise has induced three the appropriate korean adjectives; Irritate, Monotonous, stuffy and dryness. The result of this study may be used to evaluate the acoustic threshold level for indoor noise or a basis for specifying the desired acoustic environment of dwellings.
Three-dimensional Vibration Analysis of Circular Rings with an Elliptical or Circular Cross-section
Shim, Hyun-Ju ; Woo, Ha-Young ; Kang, Jae-Hoon ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1024~1035
DOI : 10.5050/KSNVN.2006.16.10.1024
A three-dimensional (3-D) method of analysis is presented for determining the free vibration frequencies and mode shapes of thick, complete (circumferentially closed), circular rings with an elliptical or circular cross-section. Displacement components
in the radial, circumferential, and axial directions, respectively, are taken to be periodic in
and in time, and algebraic polynomials in the r and z directions. Potential (strain) and kinetic energies of the circular rings are formulated, and upper bound values of the frequencies are obtained by minimizing the frequencies. As the degree of the polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies of the rings. Novel numerical results are presented for the circular rings having an elliptical cross-section based upon 3-D theory. Comparisons are also made between the frequencies from the present 3-D Ritz method and ones obtained from thin and thick ring theories, experiments, and another 3-D method.
Vibration Characteristics of the Floor Structures Inserted with Damping Materials
Jeon, Jin-Yong ; Jeong, Young ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1036~1043
DOI : 10.5050/KSNVN.2006.16.10.1036
Damping materials for reducing heavy-weight floor impact noise in reinforced concrete structures were tested in apartment buildings. The effect of damping materials and an impact isolator were compared with an on-site experiment conducted in a high-rise apartment building. The loss factor of damping material analyzed more than 2 times than rubber to
, could know that Damping layer has excellent attenuation performance in side of vibration reduction. The results showed that the resonance frequency increased but vibration acceleration level decreased when the damping materials were used. The heavy-weight impact sound levels of the structure decreased substantially at 63 Hz, whereas the sound levels of the structure with the impact isolator increased.
The Measurements of Vibration Displacement of the Piezoelectric Exciter Using Mach-Zehnder Optical Fiber Interferometer
Cho, Seung-Il ; Kim, Sung-Boo ; Lee, Jong-Kyu ; Lee, Yong-Bong ; Lee, Doo-Hee ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1044~1049
DOI : 10.5050/KSNVN.2006.16.10.1044
The vibration exciter with the accurate calibration requires a low distortion along a single axis over a wide range of frequency. The fabricated piezoelectric exciter was composed of a base, piezoelectric element(Venitron PZT 5A), electrode and seismic mass. Its performance characteristics is evaluated the Mach-Zehnder optical fiber interferometer. The phase of the optical wave passing through the optical fiber around the piezoelectric element was related the vibrational amplitude with a change of the applied sinusoidal voltage on the piezoelectric element. The dynamic characteristics of vibration exciter can be obtained by measuring the vibrational amplitude with a sinusoidal applied voltage on the piezoelectric element. The sensitivity of the fabricated piezoelectric exciter had a 0.4 nm/V which was uniform up to 20 kHz.
Vibration Analysis of Pipes Considering Fluid Pulsation
Seo, Young-Soo ; Jeong, Seok-Hyeon ; Lee, Seong-Hyeon ; Hong, Chin-Suk ; Jeong, Weui-Bong ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1050~1056
DOI : 10.5050/KSNVN.2006.16.10.1050
In this paper, a new method for the stability analysis of a pipe conveying fluid which pulsates periodically is presented. The finite element model is formulated liking into consideration of the effects of the fluid pulsating in a pipe. The damping and stiffness matrices in the finite element equation vary with time due to pulsating fluid. Coupled effects of several harmonic components in the velocity of fluid to a pipe is discussed. A new unstable region appears which will not appear in the stability analysis of single pulsating frequency. A method to directly estimate the forced response of pipe is also discussed. The results presented in this paper are verified by the time domain analysis.
Rapid Cooling Mechanism Utilizing Acoustic Streaming Generated by Ultrasonic Vibrations
Loh, Byoung-Gook ; Kwon, Ki-Jung ; Lee, Dong-Ryul ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1057~1066
DOI : 10.5050/KSNVN.2006.16.10.1057
Acoustic streaming Induced by longitudinal vibration at 30 kHz is visualized for a test fluid flow between the stationary glass plate and ultrasonic vibrating surface with particle imaging velocimetry (PIV) To measure an increase in the velocity of air flow due to acoustic streaming, the velocity of air flow in a gap between the heat source and ultrasonic vibrator is obtained quantitatively using PIV. The ultrasonic wave propagating into air in the gap generates steady-state secondary vortex called acoustic streaming which enhances convective cooling of the stationary heat source. Heat transfer through air in the gap is represented by experimental convective heat transfer coefficient with respect to the gap. Theoretical analysis shows that gaps for maximum heat transfer enhancement are the multiple of half wavelength. Optimal gaps for the actual design are experimentally found to be half wavelength and one wavelength. A drastic temperature variation exists for the local axial direction of the vibrator according to the measurement of the temperature distribution in the gap. The acoustic streaming velocity of the test fluid in the gap is at maximum when the gap agrees with the multiples of half wavelength of the ultrasonic wave, which are specifically 6 mm and 12 mm.
An Experimental Evaluation of Friction Noise between Road Surface and Tyre
Kim, J.H. ; Choi, T.M. ; Moon, S.H. ; Seo, Y.G. ; Park, J.S. ; Do, C.S. ; Cho, D.S. ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1067~1073
DOI : 10.5050/KSNVN.2006.16.10.1067
In this paper, we present noise measurement results of 8 vehicles. The measurement was done by a close proximity method attaching surface microphones on the test vehicle. For the 9 road surface types constructed at Korean highway test road, the vehicles were tested from 50 to 120 km/h at the interval of 10 km/h in normal steady state and inertia cruising conditions. Using the results, we evaluate and discuss the effect of vehicle noise generation depending on the different conditions for vehicle type, speed, road surface and loading condition, especially focused on friction noise between tyre and road surface.
Dynamic Stability Analysis of Clamped-Hinged Columns with Constant Volume
Kim, Suk-Ki ; Lee, Byoung-Koo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1074~1081
DOI : 10.5050/KSNVN.2006.16.10.1074
This paper deals with the dynamic stability analysis of clamped-hinged columns with constant volume. Numerical methods are developed for solving natural frequencies and buckling loads of such columns, subjected to an axial compressive load. The parabolic taper with the regular polygon cross-section is considered, whose material volume and column length are always held constant. Differential equations governing both free vibrations and buckled shapes of such columns are derived. The Runge-Kutta method is used to integrate the differential equations, and the Regula-Falsi method is used to determine natural frequencies and buckling loads, respectively. The numerical methods developed herein for computing natural frequencies and buckling loads are found to be efficient and robust. From the numerical results, dynamic stability regions, dynamic optimal shapes and configurations of strongest columns are reported in figures and tables.
Flow-induced Vibration Analysis for Cascades with Stator-rotor Interaction and Viscosity Effect
Oh, Se-Won ; Park, Oung ; Kim, Dong-Hyun ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 16, issue 10, 2006, Pages 1082~1089
DOI : 10.5050/KSNVN.2006.16.10.1082
In this study, advanced computational analysis system has been developed in order to investigate flow-induced vibration(FIV) phenomenon for general stator-rotor cascade configurations. Relative movement of the rotor with respect to stator is reflected by modeling Independent two computational domains. Fluid domains are modeled using the unstructured grid system with dynamic moving and local deforming methods. Unsteady, Reynolds-averaged Wavier-stokes equations with one equation Spalart-Allmaras and two-equation SST
turbulence models are solved for unsteady flow problems and also relative moving and vibration effects of the rotor cascade are fully considered. A coupled implicit time marching scheme based on the Newmark integration method is used for computing the governing equations of fluid-structure interaction problems. Detailed vibration responses for different flow conditions are presented and then vibration characteristics are physically investigated in the time domain as computational virtual tests.