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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
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Journal DOI :
The Korean Society for Noise and Vibration Engineering
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Volume & Issues
Volume 15, Issue 12 - Dec 2005
Volume 15, Issue 11 - Nov 2005
Volume 15, Issue 10 - Oct 2005
Volume 15, Issue 9 - Sep 2005
Volume 15, Issue 8 - Aug 2005
Volume 15, Issue 7 - Jul 2005
Volume 15, Issue 6 - Jun 2005
Volume 15, Issue 5 - May 2005
Volume 15, Issue 4 - Apr 2005
Volume 15, Issue 3 - Mar 2005
Volume 15, Issue 2 - Feb 2005
Volume 15, Issue 1 - Jan 2005
Selecting the target year
The Optimal Design for Noise Reduction of the Intake System in Automobile Using DACE Model
Ryu, Je-Seon ; Jin, Jung-Un ; Cha, Kyung-Joon ; Oh, Jae-Eung ; Sim, Hyoun-Jin ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1123~1130
DOI : 10.5050/KSNVN.2005.15.10.1123
We propose an optimal design to improve the capacity by reducing the noise of the intake system. The length and radius of each component of the current Intake system are selected as control factors. We accept the output from computer simulator with orthogonal arrays. Then, the Kriging estimates are computed. From this, we exploit the optimal design of the intake system by adapting simulated annealing. From the results of this optimal design, we conclude that Kriging method with the orthogonal arrays is the efficient method for Design and Analysis of Computer Experiments and we propose the useful results for the low noise intake system.
Application of Minimum Phase Condition to the Acoustic Reflection Coefficient Measurement
Heo, Jun-Hyeok ; Kim, Deok-Ki ; Lim, Byoung-Duk ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1131~1136
DOI : 10.5050/KSNVN.2005.15.10.1131
For the accurate measurement of acoustic properties of a surface, efforts have been made to reduce errors caused by external disturbance. If the reflection coefficient is considered as a transfer function between reflected wane and incident wave, the causality is required between them and the reflection coefficient should be of minimum phase. In this thesis, the minimum phase condition is applied to measure correct reflection coefficient. The reflection coefficient is approximated as a rational function In the Z domain by minimizing the sum square error. Then the minimum phase reflection coefficient is reconstructed using the distribution of poles and zeros of the reflection coefficient model.
Vibration Analysis of Flexible Rotor Having a Breathing Crack
Jun, Oh-Sung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1137~1147
DOI : 10.5050/KSNVN.2005.15.10.1137
The dynamic response due to the unbalance and crack and the quasi-static response due to gravity are analytically derived based on the complex transfer matrix. The additional slope is expressed as function of the bending moment at crack position based on the fracture mechanics concept, and inversely the bending moment is expressed as function of the additional slope at the crack Position. At each angle step during the shaft revolution, the additional slope and bending moment are calculated by an iterativemethod. The transient behavior is considered by introducing Fourier series expansion concept for the additional slope. Simulation is carried out for a simple rotor similar to those available in the literature and comparison of the basic crack behavior is shown. Using the additional slope, the cracked rotor behavior is explained with the crack depth increased: the magnitude of the additional slope increases and the closed crack duration during a revolution decreases as the crack depth increases. The direction of unbalance is also shown as a factor to affect the crack breathing. Whirl orbits are shown near the sub-critical speed ranges of the rotor.
Robust Servo Design and Application for Optical Disk Drive Using Robust Control Theory : H
Lee, Kwang-Hyun ; Yang, Hyunseok ; Park, No-Cheol ; Park, Young-Pil ; Choi, Jin-Young ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1148~1159
DOI : 10.5050/KSNVN.2005.15.10.1148
In this paper, the various uncertainties generated in an optical disk drive (ODD) and the robust servo designs considering the uncertainties are studied. First, the brief introduction an ODD and the servo error tolerance of it are discussed. Then, the classifications of uncertainty and the concept of relative stability are introduced. Considering the uncertainty of an ODD, two robust control approaches are applied: (i) mixed sensitivity approach in H
control theory for unstructured uncertainty, (ii) QFT for structured uncertainty Finally, the designed controllers are realized by DSP, and these controllers are applied to a commercial DVD-ROM drive. From these experiments, we prove that the designed robust controllers have more good disturbance rejection performance and robustness when it is compared to the conventional lead-lag controller.
Floor Impact Noise Measurement and Evaluation Method Using Impact Ball
Jeon, Jin-Yong ; Jeong, Jeong-Ho ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1160~1168
DOI : 10.5050/KSNVN.2005.15.10.1160
Floor impact noise isolation performance of reinforced concrete floors was investigated through new measurement method using impact bail. Strong impact force in Bow frequency band below 63 Hz of bang machine is not similar to human impact source and causes some problem in evaluating heavy-weight Impact noise but heavy-weight impact noise measurement and evaluation using impact ball which is very similar to human impact is more reliable than bang machine. Correction value on the background noise and sensitivity of residents should be considered on the floor impact noise evaluation classes
A Study on the Characteristic of Driving Sound Noise for Various Optical Disk Drives
Oh, Se-Won ; Kim, Yu-Sung ; Kim, Dong-Hyun ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1169~1176
DOI : 10.5050/KSNVN.2005.15.10.1169
In this study, experimental tests for driving noise of various optical disk drives (ODD) have been performed using 1/2` microphone noise measurement system. Several new and old ODD models by different manufacturers are practically considered and compared for realistic driving conditions. Sound insulation case with absorbing material for the present experimental tests is designed and constructed using CATIA system. It is found that average data transfer rate, operating RPM, and sound noise level seem to be different for the ODD models with same denoted speed by different manufacturers. Moreover, driving sound noise level can be largely affected by both tray shape and driving speed even for the condition of the same apparent data transfer rate.
High-frequency Approximate Formulation for the Prediction of Broadband Noise of Airfoil Cascades with Inflow Turbulence
Jung, Sung-Soo ; Cheung, Wan-Sup ; Lee, Soogab ; Cheong, Cheolung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1177~1185
DOI : 10.5050/KSNVN.2005.15.10.1177
This paper investigates the noise radiated by a cascade of flat-plate airfoils interacting with homogeneous, isotropic turbulence. At frequencies above the critical frequency, all wavenumber components of turbulence excite propagating cascade modes, and cascade effects are shown to be relatively weak. In this frequency range, acoustic power was shown to be approximately proportional to the number of blades. Based on this finding at high frequencies, an approximate expression is derived for the power spectrum that is valid above the critical frequency and which is in excellent agreement with the exact expression for the broadband power spectrum. The approximate expression shows explicitly that the acoustic Power above the critical frequency is proportional to the blade number, independent of the solidity, and varies with frequency as
is the wavenumber spectrum of the turbulence velocity and W is mean-flow speed. The formulation is used to perform a parametric study on the effects on the power spectrum of the blade number stagger angle, gap-chord ratio and Mach number. The theory is also shown to provide a close fit to the measured spectrum of rotor-stator interaction when the mean square turbulence velocity and length-scale are chosen appropriately.
Natural Vibration Analysis of Thick Rings
Park, Jung-Woo ; Kim, Sehee ; Kim, Chang-Boo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1186~1194
DOI : 10.5050/KSNVN.2005.15.10.1186
In this paper, we have systematically formulated the equations concerned to the in-plane and out-of-plane motions and deformations of a thick circular beam by using the kinetic and strain energies in order to analyse natural frequencies of a thick ring. The effects of variation of radius of curvature across the cross-section and also the effects of bending shear, extension and twist are considered. The equations of motion for natural vibration analysis of a ring are obtained utilizing the cyclic symmetry of vibration modes of the ring. The frequencies calculated using thick ring model and thin ring model are compared and discussed with the ones obtained from finite element analysis using the method of cyclic symmetry with 20-node hexahedral solid elements for rings with the different ratio of radial thickness to mean radius.
Effect of Moving Mass on Dynamic Behavior of Cracked Cantilever Beam on Elastic Foundations
Ahn, Sung-Jin ; Son, In-Soo ; Yoon, Han-Ik ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1195~1201
DOI : 10.5050/KSNVN.2005.15.10.1195
In this paper, the effect of a moving mass on dynamic behavior of the cracked cantilever beam on elastic foundations is presented. Based on the Euler-Bernoulli beam theory, the equation of motion can be constructed by using the Lagrange`s equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments. That is, the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory The crack is assumed to be in the first mode of fracture. As the depth of crack is increased, the tip displacement of the cantilever beam is Increased. When the depth of crack is constant, the frequency of a cracked beam is proportional to the spring stiffness.
Development of the Computer Model Considering Flexible Effect of a Large-sized Truck on the Bump Road
Moon, Il-Dong ; Chi, Chang-Hun ; Kim, Byoung-Sam ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1202~1210
DOI : 10.5050/KSNVN.2005.15.10.1202
This paper develops a computer model for estimating the bump characterisitcs of a cat)over type large-sized truck. The truck is composed of front and rear suspension systems, a frame, a cab, and ten tires. The computer model is developed using MSC.ADAMS. A shock absorber, a rubber bush, and a leaf spring affect a lot on the dynamic characteristic of the vehicle. Their stiffness and damping coefficient are measured and used as input data of the computer model. Leaf springs in the front and rear suspension systems are modeled by dividing them three links and joining them with joints. To improve the reliability of the developed computer model, the frame is considered as a flexible body. Thus, the frame is modeled by finite elements using MSC.PATRAN. A mode analysis is performed with the frame model using MSC.NASTRAN in order to link the frame model to the computer model. To verify the reliability of the developed computer model, a double wheel bump test is performed with an actual vehicle. In the double wheel bump, vortical displacement, velocity, acceleration are measured. Those test results are compared with the simulation results.
A Study on Design of Underwater Acoustic Transducers Using the Electro-mechanical Coupling Analysis Code ATILA
Lee, Jeong-min ; Cho, Yo-han ; Kim, Jung-suk ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 15, issue 10, 2005, Pages 1211~1216
DOI : 10.5050/KSNVN.2005.15.10.1211
Underwater acoustic transducers are widely used for SONAR application, whose important design parameters are shapes. materials, dimensions and supporting structures. Practical design method of transducers consists of manufacturing, experiments and modifications so that it requires much time and expenses. In this study, an analytical method was developed for the Tonpilz type transducers using the commercial finite element analysis code ATILA which can solve the electro-mechanical coupling problems. A finite element model was established including the transducer elements such as ceramic stack, head mass, tail mass, tensile bolt, and molding layers. The proposed model was verified and modified by comparing the in-air and in-water test results of prototypes. The developed analysis method will be effectively used for the sensitivity analysis of design parameters in transducer design process.