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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 22, Issue 12 - Dec 2012
Volume 22, Issue 11 - Nov 2012
Volume 22, Issue 10 - Oct 2012
Volume 22, Issue 9 - Sep 2012
Volume 22, Issue 8 - Aug 2012
Volume 22, Issue 7 - Jul 2012
Volume 22, Issue 6 - Jun 2012
Volume 22, Issue 5 - May 2012
Volume 22, Issue 4 - Apr 2012
Volume 22, Issue 3 - Mar 2012
Volume 22, Issue 2 - Feb 2012
Volume 22, Issue 1 - Jan 2012
Selecting the target year
Study of Wrinkle Effect on Primary Natural Frequency of Nano-resonator
Yoon, Juil ; Kang, Sang-Wook ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1157~1163
DOI : 10.5050/KSNVE.2012.22.12.1157
Natural frequency of a nano-resonator via nano transfer printing is studied. Through a nano transfer printing, the hybrid metal/polymer membrane may evolve a wrinkle. Natural frequency of a wrinkled hybrid membrane decreases significantly, as the amplitude to wavelength ratio becomes larger. To address the design limit of a hybrid nano resonator, we perform parametric study using finite element analysis. Specifically, we study the effects of the Young's modulus ratio of the metal/polymer membrane, thickness ratio and wrinkle amplitude to wavelength ratio, respectively. The results from the parametric studies can serve as guideline to design hybrid nano resonators.
Stability Analysis of a Wind Turbine Blade Considering Wind Force and Variation of Pitch Angle
Kwon, Seung Min ; Kang, Moon Jeong ; Yoo, Hong Hee ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1164~1171
DOI : 10.5050/KSNVE.2012.22.12.1164
Recently, researches related to the green energy generation systems have increased significantly. Among them wind turbines are the most spread practical green energy generation systems. In order to enhance the power generation capacity of the wind turbine blade, the length of wind turbine blade has increased. It might cause undesirable excessive dynamic loads. Therefore dynamic characteristics of a wind turbine blade system should be identified for a safe design of the system. In this study, the equations of motion of a wind turbine blade system undergoing gravitational force are derived considering wind force and pitch angle. Effects of wind speed, variation of pitch angle of the wind turbine blade, rotating speed, and the blade length on its stability characteristics are investigated.
Tonality Design for Sound Quality Evaluation for Gear Whine Sound
Kim, Eui-Youl ; Jang, Ji-Uk ; Lee, Sang-Kwon ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1172~1183
DOI : 10.5050/KSNVE.2012.22.12.1172
Aure's tonality was considered as the sound metrics for the expression of the tonality of gear whine sound in a previous research. It was failed to use the Aure's tonality as a sound metric for the tonal impression. Thus Aures's tonality, was developed for tonal impression in previous research. However, this metric did not express well the tonality of gear whine sound since the whine sound is a non-stationary signal with frequency modulation and amplitude modulation. In this study, the new method for the tonality evaluation for a non-stationary signal is presented. It is developed based on the prominence ratio, tonality impression function, and lower threshold level. It improves the accuracy and reliability of the sound quality index being used for the sound quality evaluation of the axle-gear whine sound.
Experimental Analysis of the Effect of Phase Change at the Entrance of a Capillary Tube by Sub-cooling Control on Refrigerant-induced Noise
Oh, Young-Hoo ; Kim, Min-Seong ; Han, Hyung-Suk ; Kim, Tae-Hoon ; Jeong, Weui-Bong ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1184~1190
DOI : 10.5050/KSNVE.2012.22.12.1184
This study is focused on the experimental analysis of the noise induced by phase change of refrigerant at the entrance of capillary tube. The refrigerant is usually two-phase condition when it flowed into the capillary tube. At the entrance of capillary tube, the phase condition of refrigerant is formed by sub-cool control. If it has sufficient sub-cool temperature, all of the vapor refrigerants turned to liquid, which means there is only liquid. Otherwise, the gas is coexisted. Based on this theory, we experiment on each case by changing sub-cool temperature using refrigerant-supplying equipment. The noise level is measured for each case and compared.
Characteristics Analysis of Highway Traffic Noise
Kim, Chulhwan ; Chang, Taesun ; Kim, Deuk Sung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1191~1198
DOI : 10.5050/KSNVE.2012.22.12.1191
Highway traffic noise is the one of the most frequent pollutant source of environmental claims in Korea for the last 10 years. For abating the noise from the highways, characteristics of highway noise source should be investigated and identified before performing the abatements. Highway noises are affected by traffic volume, vehicle types and speed, tyre and pavement types. In this study, highway noises which measured from different pavements have been analyzed and compared. Especially, the noise from the asphalt concrete pavement, cement concrete pavement and low-noise pavement have been measured simultaneously at the same traffic condition and compared each other. Hopefully, the data of the study may be used for abating highway noise and further studies.
An Empirical Acoustic Impedance Model for the Design of Acoustic Resonator with Extended Neck at a High Pressure Environment
Park, Soon-Hong ; Seo, Sang-Hyun ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1199~1205
DOI : 10.5050/KSNVE.2012.22.12.1199
An empirical acoustic impedance model of acoustic resonators with extended neck at a high sound pressure environment is proposed. The acoustic resonator with extended neck into its cavity is appropriate for the launcher fairing application because the length of neck does not increase the total height of the resonator. This enables one to design slim and light acoustic resonators for launch vehicles. The suggested acoustic impedance model considers the incident pressure and geometric variables(the neck length, the perforation ratio and the hole diameter) in terms of non-dimensional variables. Several acoustic resonators with extended neck are manufactured and their wall impedances are measured according to the pre-defined incident pressure levels. Effects of non-dimensional variables on the non-linear acoustic impedance are investigated so that a simple non-linear impedance model for the launcher fairing application can be proposed. It is demonstrated that the estimated acoustic resistance and acoustic length correction show reasonable agreement with the measured ones within the range of design parameters for launcher fairings.
Unstable Brake Pad Mode Due to Friction-velocity Slope
Nam, Jaehyun ; Kang, Jaeyoung ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1206~1212
DOI : 10.5050/KSNVE.2012.22.12.1206
The brake squeal propensity due to the friction-velocity curve is numerically investigated. The finite element models for the disc and pad are correlated with the modal test. In the friction-engaged system modeling, the friction function is linearized at the equilibrium. The damping term induced by friction-velocity slope is incorporated into the equations of motion. In the complex eigenvalue analysis, it is found that the pad shear mode is very sensitive to the friction curve. The results shows that the squeal propensity of the pad shear mode can be controlled by the design parameters such as pressure and stiffness.
A Study on Sampling Techniques to Assure the Representativeness of Short-term Equivalent Noise Level
Ryu, Hun Jae ; Ko, Joon Hee ; Chang, Seo Il ; Lee, Byung Chan ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1213~1219
DOI : 10.5050/KSNVE.2012.22.12.1213
The purpose of this study is to present a guideline to design a short-term manual measurement of environmental noise level, which is more economical and flexible, but less representative than long-term automatic measurement. The proposed guideline can provide the number of measurement times and the length of measurement term required to secure the extent of the representativeness. The data was collected at 4 sites located in Seoul and at 4 sites located outside of Seoul. The probabilities for five-minute equivalent noise levels, Leq, 5min, to stay in an error range from the quarterly representative noise level were used to evaluate sampling techniques. The probability analysis of the daytime period showed that the noise levels measured between 10 am and 2 pm and between 9 pm and 10 pm have the probabilities higher than 60 %. On the other hand, even for the same length of total measurement time, increasing the number of random samplings results in higher probabilities than increasing the length of measurement term.
Design and Performance Evaluation of Tactile Device Using MR Fluid
Kim, Jin-Kyu ; Oh, Jong-Seok ; Lee, Snag-Rock ; Han, Young-Min ; Choi, Seung-Bok ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1220~1226
DOI : 10.5050/KSNVE.2012.22.12.1220
This paper proposes a novel type of tactile device utilizing magnetorheological(MR) fluid which can be applicable for haptic master of minimally invasive surgery(MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field(or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.
Fault Detection of Rolling Element Bearing for Low Speed Machine Using Wiener Filter and Shock Pulse Counting
Park, Sung-Taek ; Weon, Jong-Il ; Park, Sung Bum ; Woo, Heung-Sik ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1227~1236
DOI : 10.5050/KSNVE.2012.22.12.1227
The low speed machinery faults are usually caused by the bearing failure of the rolling elements. As the life time of the bearing is limited, the condition monitoring of bearing is very important to maintain the continuous operation without failures. A few monitoring techniques using time domain, frequency domain and fuzzy neural network vibration analysis are introduced to detect and diagnose the faults of the low speed machinery. This paper presents a method of fault detection for the rolling element bearing in the low speed machinery using the Wiener filtering and shock pulse counting techniques. Wiener filter is used for noise cancellation and it clearly makes the shock pulse emerge from the time signal with the high level of noise. The shock pulse counting is used to determine the various faults obviously from the shock signal with transient pulses not related with the bearing fault. Machine fault simulator is used for the experimental measurement in order to verify this technique is the powerful tool for the low speed machine compared with the frequency analysis. The test results show that the method proposed is very effective parameter even for the signal with high contaminated noise, speed variation and very low energy. The presented method shows the optimal tool for the condition monitoring purpose to detect the various bearing fault with high accuracy.
Study on Establishment of the Noise Grade Criteria for Household Appliances
Park, Hyungkyu ; Lee, Jaewon ; Lee, Wooseok ; Han, Jinseok ; Gu, Jinhoi ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1237~1242
DOI : 10.5050/KSNVE.2012.22.12.1237
No matter how low it might be, noise from home appliances in indoor environment cause displeasure for residents as it is produced nearby. Electronic goods including vacuum cleaner and washing machine generate high frequency noise, which interrupts TV-watching or conversations and cause noises between floors in apartment houses. In particular, refrigerators make constant noise late at night, hampering the study for exams and causing sleeplessness. Korea, despite the government's efforts to promote low-noise goods based on the noise test by corporation, there is a lack of standardization in the test method, test condition and measuring equipments. This is a major reason that lowers the reliability of low-noise products. At present, low-noise home appliances are certified with eco labeling in the nation but, only 7 brands of refrigerators, 4 brands of washing machines and 97 brands of air-conditioners obtained certification as of august, 2011. In addition, none of Kimchi-refrigerator and vacuum cleaner brands were approved as low-noise home appliances. This shows Korea's relatively underdeveloped market for low-noise products, which, in part, is because of the difficulties companies face in being certified with eco labeling as they should satisfy various requirements such as power-saving and eco-friendly design besides low-noise features. As a result, low-noise labeling for home appliances should be established for the revised noise and vibration management law and the study was carried out to establish low-noise labeling system for major noise sources including vacuum cleaner, washing machine, air-conditioner and refrigerator.
Updating of Finite Element Models Including Damping
Lee, Gun-Myung ; Ju, Young-Ho ; Park, Mun-Soo ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1243~1249
DOI : 10.5050/KSNVE.2012.22.12.1243
Finite element models are updated in two stages in this paper. In the first stage, damping is neglected, and mass and stiffness matrices of a finite element model are updated using an optimization technique. The objective function for optimization consists of natural frequencies and mode shapes obtained from experimental modal testing data and finite element analysis. In the second stage, damping is considered with the mass and stiffness matrices fixed. A damping matrix is estimated assuming a proportional damping system. Then the damping matrix is adjusted using an optimization process so that the difference between the analytical and measured frequency response functions becomes minimum. This procedure of model updating has been applied to a simulated system and an experimental cantilever beam.
Correspondence Research of Long-term Compressive Creep of Resilient Materials and ISO 20392
Kim, Kyoung-Woo ; Yeon, Jun-Oh ; Yang, Kwan-Seop ;
Transactions of the Korean Society for Noise and Vibration Engineering, volume 22, issue 12, 2012, Pages 1250~1256
DOI : 10.5050/KSNVE.2012.22.12.1250
Resilient materials are used to reduce the floor impact sound in apartment buildings. Since an on-dol layer is installed in the resilient materials' upper part, thickness deformation can be occur in the resilient material. It is necessary to check a thickness deformation grade for a long period of time. In this research, we measured thickness deformation over 400th day to the resilient materials(EPP, EPS, EVA) which is used in Korea. Although there was a difference according to the kind of measurement test specimens, it became clear that thickness was decreases as to time increased. The thickness deformation grade of ten years after was calculated based on the thickness measurement result. Compare with the calculated result and result of ISO 20392. Larger thickness deformation occurred in the measurement result of these research findings compare with the ISO standard.