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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 14, Issue 12 - Dec 2004
Volume 14, Issue 11 - Nov 2004
Volume 14, Issue 10 - Oct 2004
Volume 14, Issue 8 - Aug 2004
Volume 14, Issue 7 - Jul 2004
Volume 14, Issue 6 - Jun 2004
Volume 14, Issue 5 - May 2004
Volume 14, Issue 4 - Apr 2004
Volume 14, Issue 9 - Mar 2004
Volume 14, Issue 3 - Mar 2004
Volume 14, Issue 2 - Feb 2004
Volume 14, Issue 1 - Jan 2004
Selecting the target year
Dynamic Characteristics Analysis of the Carriage Structure Supported by Air Bearing
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1059~1065
DOI : 10.5050/KSNVN.2004.14.11.1059
In this paper, the dynamic characteristic analysis of carriage structure supported by air bearings were performed. Toward this end, the characteristics of air bearing were numerically analyzed to estimate the stiffness of the air bearing and the clearance between air bearing and guide surface. The modal analysis of the carriage structure was performed by using finite element method, and the experimental modal analysis was also performed to validate the finite element model, where rigid body modes were compared to validate the stiffness of the air bearings. From the results, the air spring stiffness can be estimated within the range of acceptable accuracy under any pressure and clearance condition.
Design and Verification of a Large Reverberation Chamber`s Isolation System
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1066~1074
DOI : 10.5050/KSNVN.2004.14.11.1066
A vibration isolation system for a large reverberation chamber (1,228
and 1,000 ton) has been installed and verified. The reverberation chamber generates loud noise and induces high level of vibration while performing spacecraft acoustic reliability tests. The isolation system prevents vibration transfer from the chamber to the enclosure buildings. This paper describes design process and commissioning experiments of the system. Design criteria have been derived from rigid body model of the chamber. The stiffness of neoprene pads has been selected by employing finite element analysis of the reverberant chamber and isolation system. A total of 21 neoprene pads have been installed between the chamber and supporting Pedestals. A sand bag of 800kg was dropped on the chamber floor to measure the natural frequency of the isolation system. While 136.9 dB noise is generated in the chamber, absolute transmissibility of the isolation system has been measured. The measured natural frequency of the chamber is 10.2Hz, which is 80% of the predicted value. Overall transmissibility at working frequency range (25∼10.000 Hz) is less than -12.4 dB.
Shock Analysis of Head and Disk in Hard Disk Drive According to Various Rotating Speed
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1075~1082
DOI : 10.5050/KSNVN.2004.14.11.1075
This research demonstrates the shock response analysis of a head disk assembly subjected to a half-sine shock pulse in the axial direction. In case of disk analysis, the numerical method presented by Barasch and Chen is used. Galerkin method is used with mode shape by numerical method. Head-suspension system is modeled as the cantilever in order to get simulation results. Simulation results of HDA are calculated by Runge-Kutta method. Finally, shock responses of head and disk are analyzed according to the change of the rotating speed of the disk.
Low Frequency Noise Reduction Inside Duct by Using Membrane
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1083~1090
DOI : 10.5050/KSNVN.2004.14.11.1083
Two noise reduction systems are proposed in order to overcome the geometric restriction of the reactive muffler such as an expansion chamber. First, membrane is installed as a part of a duct wall and an air cavity is covered outside membrane. Second, membrane is installed inside a duct, which gives no volume change of the duct. Structural-acoustic coupling between membrane and fluid inside the cavity and duct causes rapid impedance mismatching and thereby reflected wave. Theoretical prediction is conducted by using modal expansion approach. The results are compared with the experimental results, which show better noise reduction performance than an expansion chamber.
Fault Diagnosis of Induction Motors Using Data Fusion of Vibration and Current Signals
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1091~1100
DOI : 10.5050/KSNVN.2004.14.11.1091
This paper presents an approach for the monitoring and detection of faults in induction machine by using data fusion technique and Dempster-Shafer theory Features are extracted from motor stator current and vibration signals. Neural network is trained and Hosted by the selected features of the measured data. The fusion of classification results from vibration and current classifiers increases the diagnostic accuracy. The efficiency of the proposed system is demonstrated by detecting motor electric and mechanical faults originated from the induction motors. The results of the test confirm that the proposed system has potential for real time application.
Realization of Acoustic Scattering Holography
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1101~1106
DOI : 10.5050/KSNVN.2004.14.11.1101
There are many difficulties to get the scattered field generated by obstacle which has arbitrary shape or irregular surface impedance by using analytic solution or numerical methods. In this study, we propose a method of which makes acoustic scattering holography that can predict the far-field scattered field based on nearfield measurements. This method provides the scattered fields of each wave-number components of incident fields. We express the relationship of wave-number components between incident fields and scattered fields using scattering matrix which is transfer matrix of wave-number components. Lastly, we prove the relation between wave-number components of incident and scattered field by experiments. The errors which are caused by measurements and decomposition methods are also analyzed.
Design of Automotive Engine Cooling Fan and Study on Noise Reduction through Modification of System
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1107~1114
DOI : 10.5050/KSNVN.2004.14.11.1107
Axial fans are widely used for automotive engine cooling device due to their ability to produce high flow rate to keep engine cool. At the same time, the noise generated by these fans causes one of the most serious problems. Especially, engine cooling fan noise in idle condition of a car is noticeable. Therefore. the high efficient and low-noise fan is seriously needed. When a new fan system is designed, system resistance and non-uniform inflow are the key factors to get the high performance and low noise fan system. In this study, aerodynamic and acoustic calculations are carried out on the automotive cooling fan and system. Effects of various design parameters are studied through the free wake analysis and experiments. Better performance and noise characteristic are obtained for the new design fan using the methodology. Furthermore through the modification of the fan system geometry parameters, the fan system produce more flow rate and become less noisy.
The Effect of a Tip Mass on Dynamic Stability of Pipes on Elastic Foundations
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1115~1122
DOI : 10.5050/KSNVN.2004.14.11.1115
The paper discussed the effect of a tip mass on the stability of pipes on elastic foundations. Governing equations of motion are derived by extended Hamilton`s principle, and the numerical scheme using finite element method is applied to obtain the discretized equations. With or without internal damping, the critical flow velocities of the pipes are investigated according to the variation of elastic foundation parameters and tip mass ratios. Also. the relationship between the eigenvalue branches and the corresponding flutter modes of the cantilevered pipes with a tip mass on the elastic foundations is fully investigated.
The Measurement of Firing Noise of K2 Rifle at Close Distance
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1123~1128
DOI : 10.5050/KSNVN.2004.14.11.1123
An experimental study on firing noise of K2 rifle was performed. Firing noises of K2 rifle were measured at close distance to rifle. Firing noise of K2 rifle which made in Korea, has not measured before. The measurement of firing noise at close distance is not simple, because the amplitude of firing noise is much bigger than the measuring limit of ordinary sound level meter even though it uses a signal attenuator. The measurement of firing noise at close distance is necessary for noise source positioning and for obtaining the sound power of K2 rifle. By this experimental study, the firing noise levels of K2 rifle at different positions are obtained and these data can be used to Predict the sound pressure level at any distance from muzzle of the rifle. Also these data can be used to calculate the threshold shift of gunner`s ear.
Mount Design of Helicopter FLIR Sensor Using Experimental Dynamic Model
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1129~1136
DOI : 10.5050/KSNVN.2004.14.11.1129
The structural modification to install a heavy sensor was made at the front extremities of the foreign-produced helicopter operated in the Korea Navy Mounting the sensor directly to the nose structure is unlikely to be practical because it lowers a dynamic mode of the airframe close to rotor blade passing frequencies, leading to increased helicopter vibration. Unfortunately we have no information on dynamic characteristics of the imported helicopter. So the experimental modal model derived from shake testing on the overall airframe of a working helicopter was used to solve the sensor Installation problems. The sensitivity analysis was done to evaluate what the best of modification woo)d be. Simple ID model and experimental modal data for mount system with sensor were Incorporated into overall dynamic model to assess the effects of the sensor installation on helicopter. Modal testing for the modified helicopter shows that the airframe modes are sufficiently displaced from rotor passing frequencies. The mount system has been proven fight to be sufficiently stable to meet vibration-level requirement for all required operational profiles.
An Experimental Study on Evaluation of the Sound Insulation for Balcony Window in Apartment Houses
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1137~1146
DOI : 10.5050/KSNVN.2004.14.11.1137
In an apartment house In Korea, the balcony is one of the important spaces as a buffer zone for controlling the outdoor environments such as noise, heating & cooling load, humidity etc. Because most areas of building facade in apartment building occupy the area of balcony window the sound Insulation design of It Is very Important to provide the quiet indoor environment. The aim of this research is to evaluate the sound insulation of balcony windows in apartment building by new and revised Korean Industrial Standards. We measured and studied the sound insulations of 18 balcony windows by the type of measuring methods, noise sources, correction of reverberation time in balcony and so on. The results show that the single-number quantities for sound insulation of windows are ranged from 24 dB to 30 dB.
Optimal Design of the Optical Pickup Actuator Coil
Woo Chul, Kim ; Jae Eun, Kim ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1147~1152
DOI : 10.5050/KSNVN.2004.14.11.1147
The objective of this work is to develop a new design method to find optimal coils, especially the optimal coil configuration of an optical pickup actuator. In designing actuator coils, the developed Lorenz force in the coils along the desired direction should be made as large as possible while forces and torques in other directions should be made as small as possible. The design methodology we are developing is a systematic approach that can generate optimal coil configurations for given permanent magnet configurations. To consider the best coil configuration among all feasible coil configurations, we formulate the design problem as a topology optimization of a coil. The present formulation for coil design is noble in the sense that the existing topology optimization is mainly concerned with the design of yokes and permanent magnets and that the optimization of actuator coils is so far limited within shape or size optimization. Though the present design methodology applies to any problem, the specific design example considered is the design of fine-pattern tracking and focusing coils.
An Experiment Study on the Structure-borne Noise Reduction of Building Nearby the Road by Using Ballast Mat Pavement Method
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1153~1160
DOI : 10.5050/KSNVN.2004.14.11.1153
In contemporary society, vibration and noise in the road nearby buildings have become social problems as vehicles operation has increased. Especially. in the case of the building used to art performance, available suitability of the building is tested by the indoor noise class. Therefore, the Purpose of this paper is the measurement of the structure-borne noise of Seoul Art Center nearby Umyeonsan tunnel and analyzing the effects of countermeasure to it. To measure the effects of countermeasure, not only structure-borne noise is measured, but also the vibration is measured, before and after the construction of Pavement using pad and porous asphalt. Consequently, the sound pressure level in art center 1st floor is reduced after mat pavement method, structure-borne noise that was high In 25Hz wide-band before pavement decreased regardless of experimental vehicle`s velocity Using porous asphalt pavement the noise was reduced about 3 dB(A).
Status and Characteristics of High Speed Railway Noise
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1161~1165
DOI : 10.5050/KSNVN.2004.14.11.1161
Railway noise Is one of the main causes of environmental impact. Whenever a new railway line is planned or a housing project near an existing railway is proposed, an estimate of the relevant noise levels is usually required. For this, it is necessary to quantify those parameters that affect the railway noise. Therefore we investigated the noise level which 107 high speed trains generated passing through the block of test railway track between Chunan and Chungwon. This paper shows the status and characteristics of the high speed rallway noise and an accurate prediction of the high speed railway noise.
A Study on the Noise Near the Butane-can Explosion Location
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1166~1175
DOI : 10.5050/KSNVN.2004.14.11.1166
People in the advanced society have deep interest in such environmental problems as noise, air quality, water pollution, etc. This paper submits the result of the research on the noise In the surroundings of the butane can explosion location. First, the noise level measured in a residential area, 245 meters` away from the butane can explosion location, was 59.3 dB. Also, the noise level measured in the IGUP (International Graduate University of Peace), 300 meters` away from the explosion site, was 52.5 dB. Second, the above noise levels are lower than the level specified In the Environmental Standard (65 dB), which represented that the experiment was safe. Third, the noise level in a place away from the butane can explosion location varied in accordance with the direction of the wind. Consequently, the noise in all locations (the places where damage to people is expected) surrounding the experimental butane can explosion location was measured to identify the effect of the wind irection.
Repeatable Run-out Reduction by Servo Track Writing in Semi-vacuum Condition for Ultra-high TPI Disk Drive
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1176~1181
DOI : 10.5050/KSNVN.2004.14.11.1176
In high-capacity disk drives with ever-growing track density, the allowable level of position error signal(PES) is becoming smaller and smaller. In order to achieve the high TPI(track per inch) disk drive, it is necessary to improve the writing accuracy during the servo track writing(STW) Process through the reduction of track mis-registration sources. Among the main contributors of the non-repeatable runout(NRRO) PES, the disk vibration and the head-stack assembly vibration is considered to be one of the most significant factors. Also the most contributors of repeatable runout(RRO) come from the contributors of NRRO which is written-in at the time of STW process. In this paper, the effect of NRRO on servo written-in RRO is Investigated by experimentally, and the experimental result shows that the written-in RRO can be effectively reduced through a STW process under low dense medium condition such as semi-vacuum.
Disturbance Observer Based Sliding Mode Control for Multi-DOF Active Magnetic Bearing System Subject to Base Motion
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1182~1194
DOI : 10.5050/KSNVN.2004.14.11.1182
This paper addresses the application of an active magnetic bearing (AMB) system to levitate the elevation axis of an electro-optical sight mounted on a moving vehicle. In this type of system, it is desirable to retain the elevation axis in an air-gap between magnetic bearing stators while the vehicle is moving. To eliminate disturbance responses, a disturbance observer based sliding mode control is developed. This control can decouple disturbance observation dynamics from sliding mode dynamics and preserves the robustness of the sliding control. The sliding surfaces are designed in the consideration of scattering of received image. The proposed control is applied to a 2-DOF active magnetic bearing system subject to base motion. Along with experimental results, the feasibility of the proposed technique is illustrated.
A Study on Development of Sound Quality Index of a Refrigerator Based on Human Sensibility Engineering
Transactions of the Korean Society for Noise and Vibration Engineering, volume 14, issue 11, 2004, Pages 1195~1202
DOI : 10.5050/KSNVN.2004.14.11.1195
The international competition in refrigerator markets has continuously required the research for sound quality of a refrigerator to improve the quality of a life. In this paper, A new method for evaluation of the sound quality of a refrigerator is developed based on human sensibility engineering by using ANN(artificial neural network). In this paper, the loudness and the sharpness of the refrigerator`s signals was used for the input value in ANN`s training process because the loudness and the sharpness has a good correlation between the output of the ANN and the target of the individual evaluation In the training process. Two input factor was used repeatedly in the training process to get more optimum weighting value. And then finally we developed the sound quality index of a refrigerator. The developed sound quality index was confirmed by the 96.5 % of correlation between the output of the ANN and the real evaluation. It will be applied to evaluate the sound quality of a refrigerator in the industry.