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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 18, Issue 12 - Dec 2008
Volume 18, Issue 11 - Nov 2008
Volume 18, Issue 10 - Oct 2008
Volume 18, Issue 9 - Sep 2008
Volume 18, Issue 8 - Aug 2008
Volume 18, Issue 7 - Jul 2008
Volume 18, Issue 6 - Jun 2008
Volume 18, Issue 5 - May 2008
Volume 18, Issue 4 - Apr 2008
Volume 18, Issue 3 - Mar 2008
Volume 18, Issue 2 - Feb 2008
Volume 18, Issue 1 - Jan 2008
Selecting the target year
Proposition of Copper - Foil Magnetic Sensor for the Two-axis Remote Measurement of Bending Vibration of a Non-metallic Cylinder
Kim, Jin-Ki ; Han, Soon-Woo ; Kim, Yoon-Young ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 381~385
DOI : 10.5050/KSNVN.2008.18.4.381
This paper suggests a non-contact sensor for measuring bending vibration of a non-metallic cylinder in two orthogonal directions simultaneously. Recent research shows that a solenoid can pick up bending vibrations of a nonmetallic cylinder based on the reversed Lorentz force mechanism if an electrically conductive patch is attached to the cylinder. In this work, pairs of specially designed patches are used to make two independent paths for the current induced by bending vibrations, which enables the measurement of bending vibrations along two orthogonal directions simultaneously. The working performance of the developed sensor was verified by using two accelerometers.
Active Vibration Control Using Piezostack Based Mount
Nguyen, Vien-Quoc ; Choi, Sang-Min ; Paeng, Yong-Seok ; Han, Young-Min ; Choi, Seung-Bok ; Moon, Seok-Jun ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 386~392
DOI : 10.5050/KSNVN.2008.18.4.386
This paper presents active vibration control performance of a hybrid mount. The proposed hybrid mount is devised by adopting both piezostack as an active actuator and rubber as a passive element. After experimentally identifying actuating force characteristics of the piezostack and dynamic characteristics of the rubber, the hybrid mount was designed and manufactured. Subsequently, a vibration control system with a specific mass loading is constructed, and its governing equations of motion are derived. In order to actively attenuate vibration transmitted from the base, a feedforward controller is formulated and experimentally realized. Vibration control responses are then evaluated in time and frequency domains.
Sound Quality Evaluation and Grade Construction of the Level D Noise for the Vehicle Using MTS
Park, Sang-Gil ; Park, Won-Sik ; Sim, Hyoun-Jin ; Lee, Jung-Youn ; Oh, Jae-Eung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 393~399
DOI : 10.5050/KSNVN.2008.18.4.393
The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver`s perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.
A Study on the Transmitted Energy Contribution Analysis of SUV Engine Mount by Vibration Power Flow Measurement
Kim, Su-Gon ; Lee, Sang-Kwon ; Kim, Sung-Jong ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 400~410
DOI : 10.5050/KSNVN.2008.18.4.400
Reduction of structure-borne noise in the compartment of a car is an important task in automotive engineering. Many methods which analyze noise transfer path have been generally used for structure-borne noise. These methods are useful in solving particular problem but do not quantify the effectiveness of vibration isolation for each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow measurement has been used for a simple isolation system or a laboratory based isolation system. This paper identifies the transfer path of booming noise in a SUV. The powertrain used for test has a in-line 4cylinder engine and 5-shift auto-transmission. This powertrain is transversely supported by four isolators. We calculated the energy flow throughout four isolator by the measurement of power flow and the contribution of energy flow at each isolator.
An Efficient Transmissibility-design Technique for Pneumatic Vibration Isolator
Lee, Jeung-Hoon ; Kim, Kwang-Joon ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 411~423
DOI : 10.5050/KSNVN.2008.18.4.411
Pneumatic vibration isolator has a wide application for ground-vibration isolation of vibration-sensitive equipments. Recent advances In precision machine tools and instruments such as nano-technology or medical devices require a better isolation performance, which can be efficiently done by precise modeling- and design- of the isolation system. This paper will discuss an efficient transmissibility design method for pneumatic vibration isolator by employing the complex stiffness model of dual-chamber pneumatic spring developed in our previous research. Three design parameters of volume ratio between the two pneumatic chambers, the geometry of capillary tube connecting the two pneumatic chambers and finally the stiffness of diaphragm necessarily employed for prevention of air leakage were found to be important factors in transmissibility design. Based on design technique that maximizes damping of dual-chamber pneumatic spring, trade-off among the resonance frequency of transmissibility, peak transmissibility and transmissibility in high frequency range was found, which was not ever stated in previous researches. Furthermore this paper will discuss about negative role of diaphragm in transmissibility design. Then the design method proposed in this paper will be illustrated through experiment at measurements.
Development of Underwater Wide-band Acoustic Transducer Using the 1-3 Piezoelectric Composite
Lee, Kyung-Woo ; So, Hyoung-Jong ; Lim, Sil-Mook ; Kim, Won-Ho ; Kim, Dae-Yun ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 424~431
DOI : 10.5050/KSNVN.2008.18.4.424
Recently, it is required that acoustic transducers for underwater detection and communication sensor have wide bandwidth and low operating frequency. In this research, the new acoustic transducer is proposed. This transducer is tonpilz type, and made of 1-3 piezoelectric composites as a driving parts. The developed transducer is evaluated the TVR(transmission voltage response) and RVS(receiving voltage sensitivity) characteristics around
frequency range and is compared to conventional tonpilz transducer made of solid piezoelectric ceramics as a driving parts. The resonance frequency of the developed transducer is decreased by 30% and the -3 dB bandwidth is increased by 90%, compared to conventional transducer with same dimensions. The value of TVR is decreased by 9 dB and The value of RVS is the same at resonance frequency.
Performance Characteristics of High Speed Jetting Dispenser Using Piezoactuator
Yun, Bo-Young ; Nguyen, Quoc-Hung ; Sohn, Jung-Woo ; Choi, Seung-Bok ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 432~438
DOI : 10.5050/KSNVN.2008.18.4.432
This paper presents a new jetting dispenser driven by a piezoelectric actuator at high operating frequency to provide very small dispensing dot size of adhesive in modern semiconductor packaging processes. After describing the mechanism and operational principle of the dispenser, a mathematical model of the structured system is derived by considering behavior of each component such as piezostack and dispensing needle. In the fluid modeling, a lumped parameter method is applied to model the adhesive whose rheological property is expressed by Bingham model. The governing equations are then derived by integrating the structural model with the fluid model. Based on the proposed model, dispensing performances such as dispensing amount are investigated with respect to various input trajectories.
Structural Modification for the Reduction of Radiation Noise of a Powertrain Based on CAE Technology
Song, Min-Keun ; Oh, Ki-Seok ; Lee, Sang-Kwon ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 439~447
DOI : 10.5050/KSNVN.2008.18.4.439
One of the key elements in efforts to minimize noise radiation from a powertrain is the knowledge of the main radiating component and the relation between the surface vibration of a powertrain and the sound pressure. In this research, the powertrain model is developed based on FEM(finite element method). This model is applied to the prediction of the vibration of a powertrain by using ADAMS and the radiation noise by using BEM(boundary element method). According to this numerical analysis, the surface vibration of a powertrain is investigated as a source of radiated noise. This surface vibration is caused by the 1st order natural vibration of the cylinder block and its mode shape is the torsion mode. Therefore, this mode shape is modified to reduce the surface vibration of the powertrain. The radiation noise of the modified powertrain is also reduced to
. This modification is very successful for the noise reduction based on the CAE technology.
Modeling of Median-plane Head-related Impulse Responses Using a Set of General Basis Functions
Hwang, Sung-Mook ; Park, Young-Jin ; Park, Youn-Sik ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 448~457
DOI : 10.5050/KSNVN.2008.18.4.448
A principal components analysis (PCA) of the median-plane head-related impulse responses (HRIRs) in the CIPIC HRTF database reveals that the individual HRIRs in the median plane can be adequately reconstructed by a linear combination of 12 orthonormal basis functions. These basis functions can be used to model arbitrary median-plane HRIRs, which are not included in the process to obtain the basis functions. Memory size can be reduced up to 5-fold depending on the number of HRIRs to be modeled. To clarify whether these basis functions can be used to model other set of arbitrary median plane HRIRs, a numerical error analysis for modeling and a series of subjective listening tests were carried out using the measured and modeled HRIRs. The results showed that the set of individual HRIRs in the median plane, which were measured in our lab using different measurement conditions, techniques, and source positions, can be modeled with reasonable accuracy. All subjects, involved in the subjective listening test, reported not only the accurate vertical perception but also the front-back discrimination with the modeled HRIRs based on 12 basis functions.
System Identification of a Building Structure Using Wireless MEMS System
Kim, Hong-Jin ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 458~464
DOI : 10.5050/KSNVN.2008.18.4.458
The structural health monitoring has been gaining more importance in civil engineering areas such as earthquake and wind engineering. The use of health monitoring system can also provide tools for the validation of structural analytical model. However, only few structures such as historical buildings and some important long bridges have been instrumented with structural monitoring system due to high cost of installation, long and complicated installation of system wires. In this paper, the structural monitoring system based on cheap and wireless monitoring system is investigated. The use of advanced technology of micro-electro-mechanical system(MEMS) and wireless communication can reduce system cost and simplify the installation. Further the application of wireless MEMS system can provide enhanced system functionality and due to low noise densities. Identification results are compared to ones using data measured from traditional accelerometers and results indicate that the system identification using wireless MEMS system estimates system parameters accurately.
Automotive Windshield Wiper Linkage Dynamic Modeling for Vibration Analysis
Lee, Byoung-Soo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 465~472
DOI : 10.5050/KSNVN.2008.18.4.465
An automotive windshield wiper system is modeled mainly for vibration analysis purpose. The model is composed of solid links, ideal joints, imperfect joints to simulate unavoidable manufacturing defects and bushings having stiffness, contact between a wiper blade and a wind screen glass, friction, a spring and an actuator. Main stream of wiper dynamics analysis has been obtaining a closed form of system of equations using Newton`s or Lagrange`s formula and doing a numerical simulation study to understand and predict the behavior of it. However, the modeling process is complex since a wiper system is of multibody and a contact problem occurs. When imperfection, such as dead zone of a joint and stiffness of a rubber bushing, should be included, the added complexity makes the modeling difficult. Since the imperfection is understood as main cause of problematic vibration, the dynamics model of a wiper system aiming vibration analysis should include such unavoidable manufacturing defects in the model. An open form of dynamic model of a automotive windshield wiper system with imperfect joints using a commercial software is obtained and a simulation analyssis is conducted for vibration reduction study.
Analysis of Total Harmonic Distortion in Microspeaker Considering Coupling Effect
Kwon, Joong-Hak ; Kim, Kwang-Suk ; Bang, Ki-Chang ; Hwang, Sang-Moon ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 18, issue 4, 2008, Pages 473~479
DOI : 10.5050/KSNVN.2008.18.4.473
With the advent of mobile phone, digital multimedia broadcasting(DMB) service is to be realized for multimedia data communication. For an acoustic part, a smaller and lighter microspeaker is also soon to be realized as an MP3 song player and a speakerphone. Sound quality in the microspeaker is becoming more important in mobile phones. It is evaluated by total harmonic distortion(THD). THD is the proportion of higher order frequencies output response to sinusoidal input signal. It is affected by uneven magnetic distribution and nonlinear response of diaphragm. In this paper, harmonic distortion is analyzed by considering magnetic and mechanical coupling effects. Simulated results of THD are compared with experimental data. Results show that THD in lower frequency range is higher due to high displace on voice coil and high mechanical response of high order frequency.