• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.2
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• pp.118-123
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• 2002

A torque transmission system, which is composed of serveral gears and couplings, is flexible. Therefore, the torsion vibration occurs when the motor speed abruptly changes. Consequently, for accuracy characteristic response of motor, we must suppressed vibration. Therefore, vibration suppression is very important motor control. In order to suppress the vibration, various control method have been proposed. Specially, one method of vibration suppression is used disturbance observer and filter. The disturbance observer is used to suppress the vibration in this method. By feedback of the estimated torsion torque, the vibration can be suppressed. The coefficient diagram method is used to design the filter and proportional controller. But using coefficient diagram method, not adapted controller parameter in disturbance. In order to solve this problem. we used fuzzy controller for auto tuning controller parameter $K_P$. We proved of this approach is confirmed by simulation. 

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.59-66
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• 2015

The production of high value-added products requires efficient processing and this constant demand for complex shape processing has led to the need for hybrid processing. In this study, the surface characteristics of hybrid machining, which combines wire-cut E.D.M and vibration, are examined. The selected experimental parameters are verticality, waveform, amplitude, peak current and frequency. The experimental results provide a guideline for selecting reasonable machining parameters. Surface roughness was improved by increasing the amplitude of the vibration.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.81-88
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• 2016

Recently, high-efficiency machining in the production of high-value products with complex shapes has constantly been required along with the need for hybrid machining. In this study, in addition to wire-cut Electric Discharge Machining (EDM) and vibration, we present the possibility of a hybrid process by carrying out an experiment with aluminum alloy, and the hybrid process determines the nature of the surface. The selected experimental parameters are waveform, amplitude, peak current, and two-dimensional (2D) vibration. The experimental results give the guideline for selecting reasonable machining parameters. The surface roughness was improved about 20% with increases in the amplitude of the vibration.

• The Journal of the Acoustical Society of Korea
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• v.8 no.1
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• pp.31-37
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• 1989

The effectiveness of using a composite beam with constrained visco-elastic layer as a dynamic vibration absorber is investigated. The performance of this absorber is evaluated in terms of displacement transmissibility when to a primary beam with built-in ends and compared to that of the uniform beam absorber. The results of analysis and design show that it is possible to suppress simultaneoulsy the peak transmissibilities at two or more resonance frequencies and the optimal parameters are located within the available viscoelastic material properties.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.100-107
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• 2015

Recently, high-efficiency machining in the production of high-value products with a complex shape has constantly been required with the need for hybrid machining. In this study, in addition to the wire-cut E.D.M. and vibration used to present the possibility of a hybrid process by carrying out the aluminum alloy experiment, the hybrid process determines the nature of the surface. The selected experimental parameters are horizontality, waveform, amplitude, peak current, and frequency. The experimental results give guidelines for selecting reasonable machining parameters. The surface roughness was improved by about 20% with increases in the amplitude of the vibration.

• Journal of KSNVE
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• v.6 no.4
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• pp.493-497
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• 1996

TVs or computer monitors with speakers often have a phenomenon called microphonic which shows fringe-like dark pattern on their screens. The major source of this phenomenon is vibration of the shadow mask inside of the Cathode RAY Tube(CRT) which is caused by the sound generated from the speakers. Reducing phenomenon microphonic by modifying the structure of the shadow mask frame in CRT has been examined in this study. A 15" for computer monitor were chosen. Using finite element analysis for vibration and impact, shape of the shadow mask frame was found to reduce microphonic phenomeon. Improved 15" monitors showed good results.d results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.138-140
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• 2014

The image quality of the color laser printer is highly related with the motion quality of actuators. However, the high precision system requires high production costs in general. The proposed design method in this paper improves image quality without increasing production costs. Using the synchronization method, time gap between exposure and transfer in organic photo conductive (OPC) drum and the period of driving gear revolution are synchronized. The proposed method is verified by computer simulations and experiment, and showed by printed images.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1665-1671
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• 2012

The purpose of this study was to look into changes in voice using acoustic analysis during the process of neuromuscular electrical stimulation targeting dysphagia treatment. Fifteen man with dysphagia caused by stroke was treated neuromuscular electrical stimulation for two months and intensity of voice, $F_0$, Jitter, Shimmer, NNE were measured. The results of this study that improvement in functions of dysphagia and Jitter, Shimmer were stabilized. But there was not significantly changes of $F_0$. NNE was improved after the intervention, but still showed abnormal levels. This result suggests a possibility of effects that Neuromuscular electrical stimulation has on stabilization of Jitter, Shimmer and intensity of voice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.2975-2981
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• 2011

We propose an efficiency analysis method to test whether Schisandra tea is beneficial to the health of internal organs, and, if so, to find which organ is mostly benefited. Firstly, for this, the color change in the right cheek region of face images before and after drinking Schisandra tea is analyzed using image processing techniques. Also, acoustic analysis experiments on both of the vocal cords vibration and the intensity value of acoustic signal are performed to investigate further Schisandra tea's effectiveness. The results of lung function smoothly by eating omijacha become. Vocal cords vibration and voice energy intensity of the right cheek region has changed a steady increase of the b values were observed.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1430-1433
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• 2010

삶의 지표가 상승함에 따라 선진국에서는 건강에 대한 관심도가 높아져 질병이 발생되기 전에 조기에 진단하여 예방하는 건강 패턴이 행해지고 있는 실정이다. 이와 같은 예방 분야를 반영한 것이 대체의학이며 이침 요법은 부작용이 적은 방법으로 널리 사용되고 있다. 이침 요법은 교육과정을 거친 후 자가 진단을 통해 응급처지가 가능한 것으로 실생활에서 손쉽게 이용되고 있다. 따라서 본 논문에서는 신장에 해당하는 이(耳)혈 상응점을 자극하여 신장과 관련된 음성 요소의 변화를 측정하였다. 이를 위해 신장 이혈 상응점을 자극하기 전과 후의 음성을 수집하여 음성 분석 요소 중 제 1 Formant Bandwidth와 Jitter, Shimmer값을 적용하여 비교, 분석하였다. 결과적으로 신장 이혈 상응점 자극에 의해 성대 진동의 변화율이 낮아져 발음의 정확성을 나타내는 결론을 도출하였다.