• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.215-221
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• 2018

In this paper, a comprehensive design of HBC(Human Body Communication) system for capsule endoscope is presented. First, we propose a method of combining the signals received from multiple patches attached to the body of patient through differential operation and derive the signal SNR mathematically. To synchronize HBC transmission signal sent from capsule, we analyzed coarse timing synchronization method using PN code and fine timing synchronization performance among Manchester, NRZ and RZ modulation method using ZCD(Zero Crossing Detector). In addition, we evaluated the equalization performance of HBC signal frame in Rician and Rayleigh channel environments by applying LMS and RLS algorithm.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.7
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• pp.40-47
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• 1998

This paper presents the physiological signal processing CMOS one chip for transmitting human bodys small electrical signals such as electrocardiogram(EKG) or electromyogram(EMG) and the external system for receiving signals was implemented by the commercial ICs. For simultaneous four-subject four-channel telemetry, a new enfored synchronization techniqeu using infrared bi-directional communication has been proposed. The telemeter IC with the size of 5.1*5.1mm$^{2}$ has the following functions: receiving of command signal, initialization of internal state of all functional blocks, decoding of subject-selection signal, time multiplexing of 4-channel modulated physiological signals, transmitting of telemetry signal to external system and auto power down control. The newly designed synchronized oscillator with low supply voltage dependence in the telemeter IC operates at a supply voltage from 4.6~6.0V and the nonlinearity error of PIM modulator was less than 1.2%F.S(full scale). The power saving block operates at the period of 2.5ms even if the telemetry IC does not receive command signal from external system for a constant time.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.89-92
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• 2014

This paper presents a secure and blind adaptive audio watermarking algorithm based on Empirical Mode Decomposition (EMD). The audio signal is divided into frames and each one is decomposed adaptively, by EMD, into several Intrinsic Mode Functions (IMFs). The watermark and the synchronization codes are then embedded into the extrema of the last IMF. The experimental results show that the proposed method has good imperceptibility and robustness against signal processing attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1860-1875
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• 2013

In this paper, we present a comparative performance evaluation of the sampling frequency synchronization method that eliminates the initial sampling frequency offset (SFO) to reduce the overall synchronization time in Digital Radio Mondiale (DRM) receivers. To satisfy the advanced synchronization performance requirements of DRM receivers, we introduce the conventional DRM synchronization method (Method 1) and another method (Method 2), which does not perform the initial sampling frequency synchronization in the conventional synchronization method (both methods are mentioned later in this paper). To demonstrate the effectiveness of the performance evaluation, analytical expressions for frame detection are derived and simulations are provided. Based on the simulations and numerical analysis, our result shows that Method 2, with a negligible performance loss, is robust to the effects of the initial sampling frequency synchronization even if SFO is present in the DRM signal. In addition, we verify that the inter-cell differential correlation used between reference cells is robust to the effect of the initial SFO.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.505-508
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• 2003

In this paper, we introduce embedding drive synchronigation method using SC-CNN. SC-CNN provide us a good method to separate interconnected state variables of a system respectively and to make it possible to change current component to voltage component in the state variables. Using this advantage, We suggest another synchronization method called Embedding Drive Synchronization. Proposed Embedding Drive Synchronization change general drive synchronization method a little bit. we put transmitted signal between into the input of the state variables of the received part, not entirely replacing it. and we showed it proved.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.163-164
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• 2014

Pseudolite systems are used for backup systems of GPS satellite or indoor navigation systems. The pseudolite transmits GPS-like signal on the ground. Fundamentally, to estimate a position, clock synchronization among satellites is essential, because GPS receiver uses measurement based on TOA. Therefore, in order to improve the navigation performance in applications using pseudolite, clock synchronization with GPS satellites is required. This paper proposes design of monitoring system for pseudolite clock synchronization. The monitoring system analyzes clock synchronization accuracy of pseudolite and can be used for clock adjustment.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.26-32
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• 2007

Objective and Background: Laryngeal stroboscope is an useful equipment in evaluation of vocal cord vibration and in early detection of mucosal lesion including invasive cancer of the vocal cord. Recently Lee et al. (2006) developed portable stroboscope using voice as synchronization signal. It has been frequently impaired ability to synchronize the flashes even in normal female. Authors tried to investigate various methods including vibration pick-up, microphone, laryngeal microphone, and contact microphone for development of simple and accurate method like electroglottograph signal. The purpose of this study was to estimate wheher the vibration pick-up is available and is consistent with the signal of EGG. Subjects and Methods: Authors compared the signals between EGG and noncontact method such as voice, contact methods including vibration pick-up, laryngeal microphone, and contact microphone in normal twenty adults (male 10 and female 10). The number of peak in one cycle was compared with the number of the peak in EGG, and the percent of phase difference in the peak was compared with EGG Also, authors tried to investigate which site of vibration pick-up was most effective for synchronization of stobo flashes. Three site including anterior neck below the cricoid cartilage, thyroid ala, and suprahyoid region were analysed. Results: Among various methods for synchronization of strobo flashes, vibration pick-up was most effective method in peak detection. And anterior neck below cricoid cartilage was the most available site of the vibration pick-up. Conclusion: Authors suggest that vibration pick-up is most available and effective method for synchronization of strobo flashes.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.392-399
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• 2019

In this paper, we have studied wireless time division duplex(TDD) time synchronization technique considering the propagation delay between mobile vehicles. The existing IEEE 1588 precision time protocol(IEEE 1588 PTP) algorithm was applied and the time synchronization between the two nodes was achieved through the propagation delay and clock offset time correction calculated between master slave nodes during wireless TDD communication. The time synchronization process and procedure of IEEE 1588 PTP algorithm were optimized, thereby reducing the propagation delay error sensitivity for real-time moving vehicles. The sync flag signal generated through the time correction has a time synchronization accuracy of max +252.5 ns within 1-symbol(1.74 M symbol/sec, ${\pm}287.35ns$) through test and measurement, and it was confirmed that the time synchronization between master slave nodes can be achieved through sync flag signal generated during GPS disturbance.

• ETRI Journal
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• v.30 no.1
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• pp.59-67
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• 2008

The necessity for the precise time synchronization of measurement data from multiple sensors is widely recognized in the field of global positioning system/inertial navigation system (GPS/INS) integration. Having precise time synchronization is critical for achieving high data fusion performance. The limitations and advantages of various time synchronization scenarios and existing solutions are investigated in this paper. A criterion for evaluating synchronization accuracy requirements is derived on the basis of a comparison of the Kalman filter innovation series and the platform dynamics. An innovative time synchronization solution using a counter and two latching registers is proposed. The proposed solution has been implemented with off-the-shelf components and tested. The resolution and accuracy analysis shows that the proposed solution can achieve a time synchronization accuracy of 0.1 ms if INS can provide a hard-wired timing signal. A synchronization accuracy of 2 ms was achieved when the test system was used to synchronize a low-grade micro-electromechanical inertial measurement unit (IMU), which has only an RS-232 data output interface.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.909-917
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• 2009

In this paper, we proposed and implemented the method to efficiently generate TDD synchronization signal and the digital circuit for the RF repeater which can eliminate the shadow region in the wireless communication field using the time division duplex (TDD) method. After detecting the TDD signal from the transmitted or received RF signal, the detected TDD signal is fed to the RF repeater for the normal operation. The proposed technique detects the envelop of the downlink signal and amplifies the detected envelop, and then restores the degraded envelop with the proposed digital filtering method. Finally the restored envelop is manipulated to the TDD synchronization signal. Our focus on the proposed algorithm is to develop it with simple feature and low cost but robust performance. The proposed scheme was implemented to the integrated system which has both RF and digital circuit and tested under the same condition with the commercial WiBro service.