• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1860-1867
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• 2016

In this paper, first, a linearized modeling of a phase shift full-bridge converter used in chargers of electric vehicles is derived by using state-space approach and transfer functions from the duty ratio to output voltage and the inductor current are also verified. second, control systems for the output voltage and the inductor current are designed using the root locus technique. It is illustrated by experimental results that the control performance on the output variables is satisfied with the designed digital control system based on a automobile qualified 32-bit microcontroller.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.8-13
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• 2004

We presented the method to obtain four speckle interferograms with relative phase shift of $\pi$/2 by passive devices such as waveplate and polarizer, calculate the phase at each point of the speckle interferogram in shearography using Wollaston prism, and theoretically demonstrated the feasibility of the unposed method by Jones matrix.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.552-555
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• 2012

The main goal of this paper is to develop a robust visual tracking algorithm with particle filtering. Visual Tracking with particle filter technique is not easy task due to cluttered environment, illumination changes. To deal with these problems, we develop an efficient observation model for target tracking with particle filter. We develop a robust phase correlation combined with motion information based observation model for particle filter framework. Phase correlation provides straight-forward estimation of rigid translational motion between two images, which is based on the well-known Fourier shift property. Phase correlation has the advantage that it is not affected by any intensity or contrast differences between two images. On the other hand, motion cue is also very well known technique and widely used due to its simplicity. Therefore, we apply the phase correlation integrated with motion information in particle filter framework for robust tracking. In experimental results, we show that tracking with multiple cues based model provides more reliable performance than single cue.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.752-759
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• 2010

The low power consumption is the most important design factor for the In-Body communication system of WBAN. The conventional PSSK (Phase-Silence-Shift-keying) modulation technique can be regarded as an extension from PSK modulation. And this PSSK has better power efficiency than PSK modulation, and higher spectral efficiency than FSK modulation. PSSK modulation is to transmit two orthogonal symbols. The transmission power can be lowered because the symbol rate in signal period becomes half. BER performance is improved because transmission power is lower and the modulation symbol distance is widened. In addition, PSSK preserve the low-power and increase the data rate than FSK. In this paper, we analyzed existing PSSK and like to propose a new PSPM (Phase-Shift-Position-Modulation) modulation scheme. This PSPM is evaluated in terms of considered bandwidth efficiency and BER performance, compared with the PSSK. This PSPM modulation method transmits the information data by both PSK symbol data and symbol position data, so that we can significantly improve the power efficiency. New proposed PSPM method could be very useful for the In-body communication that requires the most power efficient system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.77-84
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• 2005

The orthogonal frequency division multiplexing (OFDM) technique and the single carrier with cyclic prefix (SC-CP) scheme are very attractive solutions for wireless applications, being computationally efficient since equalization is performed in the frequency domain. The equalizer could not entirely handle significant mean. Doppler shift. This motivates the use of a phase error tracking loop that operates jointly with the frequency equalizer. This paper describes the effect of the mean phase error and the performance of the proportional equalizer coupled with a phase error tracking loop based on decision-directed method. Furthermore, simulation results show that we can reduce the computational toad of the tracking loop with minimal performance degradation.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.144-149
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• 2016

In this paper, we analyze a QPSK MODEM over underwater acoustic channel model. Ambient noises and parameters of underwater environments debase the BER performance of an underwater modem. In the paper, the BER performance of uncoded QPSK and rate-2/3 convolutional coded QPSK is analyzed. And To improve BER Performance, we apply a channel equalization technique to the underwater modem.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1392-1401
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• 2015

Inverter configurations for multiple-load induction cooking applications need development. Inverter configurations for induction cooking applications are used in home appliances based on single coil inverters. For multiple-load configurations, multiple coils are used. They require proper inverters, which provide independent control for each load and have fewer components. This paper presents a three-leg inverter configuration for three load induction cooking applications. Each induction coil powers one induction cooking load. This configuration operates with constant switching frequency and powers individual loads. The output power of the required load is controlled with a phase-shift control technique. This configuration is simulated and experimentally tested with three induction loads. The simulation and experimental results are in good agreement. This configuration can be extended to more loads.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.52-60
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• 2001

In this paper proposes a multi-carrier MFSK-DPSK/DS-CDMA combined modulation techniques in Nakagami fading environment. Also, multi-carrier DS-CDMA combined system is a promising technique for mobile communications systems, since it has a strong immunity to multipath fading and increasing bandwidth efficiency. The modulations under consideration are noncoherent M-ary frequency shift keying (MFSK)and an MFSK based joint frequency phase modulation utilizing differential phase shift keying (DPSK). With the result, performance improvement of power efficiency and bandwidth efficiency combined system in multi-carrier MFSK-DPSK/DS-CDMA are better then conventional communication system.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.68-69
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• 2014

In the battery based applications such as electric vehicle and energy storage system, the performance of the system highly depends on the reliability of the battery. However, it is difficult to obtain the accurate information about the state-of-health (SOH) of battery during its operation. In this paper a 3kw battery charger with battery diagnosis function which can estimate the SOH of the battery by using online impedance spectroscopy technique is introduced. For the charger phase shift full bridge converter with synchronous rectification has been adopted to implement the charge and diagnosis functions. The impedance spectroscopy is performed after the charge to obtain the information about the internal impedance of the battery module, hence the SOH can be estimated online by observing the impedance variation of the battery over time. All the design procedure of the proposed charger is detailed and the feasibility of the system is verified by the experimental results.

• Journal of the Korean Chemical Society
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• v.21 no.4
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• pp.270-275
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• 1977

A rate constant is deduced for the reaction of tert-butoxy radicals and trimethylsilane from the measurement of the phase shift between the modulated light source and the ESR signal of trimethylsilyl radical. The rate constant was found to $3{\times}10^{-2}M^{-1}{\cdot}sec^{-1}$ at $-50^{\circ}C$.