• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.728-733
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• 2003

In human-mechanical cooperative systems, a significant issue is to improve the control performance and the maneuvering feeling of human operation. However, since it is not easy to evaluate the feeling of operators numerically, control engineers design controllers only through experience. Thus, in this paper, a new evaluation method for control performance of human-mechanical cooperative system is proposed based on the reserge waveform. Various distortions of waveform represent deteriorations of control performance and maneuvering feeling. In some cases, since there is a tradeoff between the control performance and the maneuvering feeling, it is difficult to compensate for both of them by usual feedback controllers. To overcome this situation, the two degrees of freedom control system is applied to human-mechanical cooperative system. Some numerical simulation results for an electric power steering system are shown to confirm the effectiveness of proposed control design method.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.12
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• pp.606-615
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• 2004

The discharge characteristics of a ramp reset waveform in the alternating current plasma display panel(ac PDP) were studied using a 2-dimensional numerical simulation. We analyzed the wall charge variation during the reset discharge, address discharge and sustain discharge adopting a ramp reset waveform. Then we investigated the principal parameters for a successful discharge. In this paper, we suggest a new parameter, printing particles' density and its effects on the stability of the ramp discharge. The maximum current flows of the three electrodes during the ramp reset period were decreased with the increase in the priming particles's density which was explained with the wall charge characteristics and the current flow characteristics obtained by a 2-D simulation.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.556-560
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• 2001

In this paper, a soft-switching discontinuous mode (DCM) power factor corrected (PFC) converter is analyzed by applying the double Fourier series expansion. It is found that the fundamental component and higher-order harmonics included in the input current waveform are obtained by the Fourier series expansion of the mean value of the inductor current. From the theoretical analysis, a new method removing the distortion of the input current waveform is proposed. In spite of an open loop system, the proposed method makes a great improvement of the total harmonic distortion even if the ratio of output voltage to input voltage is very low.

• Journal of Information Display
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• v.3 no.4
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• pp.13-18
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• 2002

In general, the background light that is produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to an imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes are found to occur during the reset period. We also adopted the MgO coated phosphor layer to improve the address voltage margin that was reduced when the bias voltage in the modified ramp reset waveform was applied. As a result, the address voltage margin of 45 V which is the same level of the conventional method was ortained and the dark room contrast ratio was improved up to 7500 : 1.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.10
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• pp.517-521
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• 2001

The voltage controlled ramp(VCR) waveform has recently been introduced in the reset period prior to addressing for plasma display. However, this method shows the oscillation of gap voltage when the ramp rate is increased in order to reduce reset period. In this paper a current controlled ramp(CCR) waveform method is suggested. This method can suppress the oscillation of gap voltge under the condition of shorter ramp time. Moreover, the reset time can be reduced about 30% compared with VCR method under the same background luminance.

• Journal of Biomedical Engineering Research
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• v.14 no.3
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• pp.265-272
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• 1993

We present a new waveform detection method, based on the search of distinctive line-segments. The method is based on the basic assumption that the waveform morphology of biological signals is readily characterized by a sequence of the distinctive line-segments and their structural features. In this method, the distinctive line-segments are first searched for, and a structural feature analysis is performed an the distinctive line-segments found. Experiments of detecting epileptic spikes were carried out to evaluate the detection per formance of the method. Two subjects were used for training and tuning the algorithm and four subjects for testing the method. The results were obtained on two different performance indices, detection ratio and the number of false detections per minute.

• Geomechanics and Engineering
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• v.12 no.1
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• pp.1-8
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• 2017

An experimental technique for determining the spalling strength of rock-like materials under a high strain rate is developed. It is observed that the spalling strength of a specimen can be determined by only knowing the wavelength, loading peak value and length of the first spallation of an incident wave under a specific loading waveform. Using this method in combination with a split-Hopkinson pressure bar (SHPB) and other experimental devices, the spalling strength of granite specimens under a high strain rate is tested. Comparisons with other experimental results show that the new measuring method can accurately calculate the dynamic tensile strength of rock materials under a high strain rate.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.121-122
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• 1992

We present a new EEG waveform detection method, based on the search of distinctive line-segments. The method is based on the assumption that EEG waveform morphology is characterized by a sequence of its distinctive line-segments and their structural features. In this method, the distinctive line segments are first searched for, and the structural feature analysis is performed on the found line-segment sequence. Experiments of detecting epileptic spikes are performed on four different subjects.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1391-1392
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• 2007

A selective reset waveform which can improve the dark room contrast ratio in a large sustain gap structure is suggested in this paper. When conventional selective reset discharge is performed, frequent unexpected misfiring happens because of high Vxb and much quantity of negative wall charge formed on Y electrode during final sustain period. The misfiring between sustain electrode and address electrode can be removed by lowering Vxb value and the misfiring between address electrode and scan electrode can be prevented by applying last sustain pulse of 40us and rectangular pulse of Vscan on Y electrode. When the selective reset waveform has one time reset per 8 subfields, black luminance of 1.55 cd/m2 can be obtained without any misfiring.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.9
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• pp.1271-1274
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• 2021

RF fingerprinting based on deep learning (DL) has gained interests as a means to improve the security of near field communication (NFC) by allowing identification of NFC tags based on unique physical characteristics. To achieve high accuracy in the identification of NFC tags, it is crucial to utilize a large number of training data, however it is hard to collect such dataset in practice. In this study, we have provided new methodology to generate RF waveform from NFC tags, i.e., data augmentation, based on a conditional generative adversarial network (CGAN). By using the RF waveform of NFC tags which is collected from the testbed with software defined radio (SDR), we have confirmed that the realistic RF waveform can be generated through our proposed scheme.