• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.581-586
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• 2020

In this paper, the design process and method for a compact wideband loop antenna for terrestrial digital TV (DTV) and ultra high definition (UHD) TV applications was proposed. Horizontal slits were added on the two circular sectors of the proposed loop antenna in order to miniaturize the existing wideband loop antenna consisting of a square loop and two circular sectors. A CPW transmission line was inserted in the center of the lower circular sector as a feed line. The CPW feed line was designed using the 75 ohm port impedance for DTV and UHD TV applications, and a tapered center-signal line was designed to improve the impedance matching. The final designed antenna was fabricated on an FR4 substrate with a thickness of 0.8 mm. The experiment results show that the proposed compact loop antenna operates in the frequency band of 444.3-820.1 MHz for a VSWR < 2, which fully covers the DTV and UHD TV bands.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.38-46
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• 2024

In general, EEG signal analysis has been the subject of several studies due to its ability to provide an objective mode of recording brain stimulation, which is widely used in brain-computer interface research with applications in medical diagnosis and rehabilitation engineering. In this study, we developed EEG reception hardware to measure electroencephalograms and implemented a processing system, classifying it into server and data processing. It was conducted as an intermediate-stage research on the implementation of a brain-computer interface using electroencephalograms, and was implemented in the form of predicting the user's arm movements according to measured electroencephalogram data. Electroencephalogram measurements were performed using input from four electrodes through an analog-to-digital converter. After sending this to the server through a communication process, we designed and implemented a system flow in which the server classifies the electroencephalogram input using a convolutional neural network model and displays the results on the user terminal.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.333-340
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• 2011

KJJVC(Korea-Japan Joint VLBI Correlator) was installed at the KJCC(Korea-Japan Correlation Center) and has been operated by KASI(Korea Astronomy and Space Science Institute) from 2009. KJNC is able to correlate the VLBI observed data through KVN(Korean VLBI Network), VERA(VLBI Exploration of Radio Astrometry), and JVN(Japanese VLBI Network) and its joint network array. And it is used exclusively as computer in order to process the observed data for the scientific purpose KJJVC used the VSI(VLBI Standard Interface) as the VLBI international standard at the data input-output specification between each component. Especially, for correlating the observed data, the data is transmitted with 1024Mbps speed between Mark5B high-speed playback and RVDB(Raw VLBI Data Buffer). The EMI(Electromagnetic lnterference), which is occurred by data transmission with high-speed, cause the data loss and the loss occurrence is frequently often for long transmission cable. Finally it will be caused the data recognition error by decreasing the voltage level of digital data signal. In this paper, in order to minimize the data loss by measuring the EMI noise level in transmission of the VSI specification, the 3 methods such as 1) RC filtering method, 2) lmpedance matching using Microstrip line, and 3) Signal buffering method using Differential line driver, were proposed. To verify the effectiveness of each proposed method, the performance evaluation was conducted by implementing and simulations for each method. Each proposed method was effectively confirmed as the high-speed data transmission of the VSI specification.

• ETRI Journal
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• v.29 no.3
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• pp.371-380
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• 2007

This paper proposes a new automatic compensation network (ACN) for a system-on-chip (SoC) transceiver. We built a 5 GHz low noise amplifier (LNA) with an on-chip ACN using 0.18 ${\mu}m$ SiGe technology. This network is extremely useful for today's radio frequency (RF) integrated circuit devices in a complete RF transceiver environment. The network comprises an RF design-for-testability (DFT) circuit, capacitor mirror banks, and a digital signal processor. The RF DFT circuit consists of a test amplifier and RF peak detectors. The RF DFT circuit helps the network to provide DC output voltages, which makes the compensation network automatic. The proposed technique utilizes output DC voltage measurements and these measured values are translated into the LNA specifications such as input impedance, gain, and noise figure using the developed mathematical equations. The ACN automatically adjusts the performance of the 5 GHz LNA with the processor in the SoC transceiver when the LNA goes out of the normal range of operation. The ACN compensates abnormal operation due to unusual thermal variation or unusual process variation. The ACN is simple, inexpensive and suitable for a complete RF transceiver environment.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.176-180
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• 2004

The ST-segment that the beginning part of T wave is the important diagnostic parameter to finding myocardial ischemia. Abnormal ST appears in two types. One is the level change, and the other is the pattern change. In this paper, we describe the monitoring of abnormal ST using PC based system. Hardware of this system consists of transmitter, receiver and PC. The function of transmitter is measuring ECG in three channels which are selected manually and transmitting the data to receiver by digital radio way. Connection with receiver and PC is by RS232C, and the data received on the PC is analyzed automatically by ECG analysis algorithm and saved to file. In the algorithm part for detecting abnormal ST, ST-segments are approximated by a polynomial. This method can detect all of the deviation and pattern change of ST-segment regardless the change in the heart rate or sampling rate. To gain algorithm reliability, the method rejects distorted polynomial approximation by calculation the difference between the approximated ST-segment and original ST-segment. In pre-signal processing, the wavelet transformation separates high frequency bands including QRS complex from the original ECG. Consequently, the process improves the performance of detecting each feature points.

• Journal of Information Processing Systems
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• v.12 no.2
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• pp.263-274
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• 2016

The exceptional development of electronic device technology, the miniaturization of mobile devices, and the development of telecommunication technology has made it possible to monitor human biometric data anywhere and anytime by using different types of wearable or embedded sensors. In daily life, mobile devices can collect wireless body area network (WBAN) data, and the co-collected location data is also important for disease analysis. In order to efficiently analyze WBAN data, including location information and support medical analysis services, we propose a geohash-based spatial index method for a location-aware WBAN data monitoring system on the NoSQL database system, which uses an R-tree-based global tree to organize the real-time location data of a patient and a B-tree-based local tree to manage historical data. This type of spatial index method is a support cloud-based location-aware WBAN data monitoring system. In order to evaluate the proposed method, we built a system that can support a JavaScript Object Notation (JSON) and Binary JSON (BSON) document data on mobile gateway devices. The proposed spatial index method can efficiently process location-based queries for medical signal monitoring. In order to evaluate our index method, we simulated a small system on MongoDB with our proposed index method, which is a document-based NoSQL database system, and evaluated its performance.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.12
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• pp.1479-1485
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• 1999

This paper proposes a fuzzy decision making method for power transformer protection to identify an internal fault from other transient states such as inrush, over-excitation and an external fault with current transformer (CT) saturation. In this paper, analyzing over 300 EMTP simulations of disturbances, four input variables are selected and fuzzified. At every sampling interval from half to one cycle after a disturbance, from the EMPT simulations, different fuzzy rule base is composed of twelve if-then fuzzy rules associated with their basic probability assignments for singleton- or compound-support hypotheses. Dempster's rule of combination is used to process the fuzzy rules and get the final decision. A series of test results clearly indicate that the method can identify not only an internal fault but also the other transients. The average of relay operation times is about 12(ms). The proposed method is implemented into a Digital Signal Processor (TMS320C31) and tested.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.10a
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• pp.39-45
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• 2000

A small camera module fabricated by including bare chip bonding methods is utilized to realize advanced mobile devices. One of the driving forces is the TOG (Tape On Glass) bonding method which reduces the packaging size of the image sensor clip. The TOG module is a new thinner and smaller image sensor module, using flip chip interconnection method with the ACP (Anisotropic Conductive Paste). The TOG production process was established by determining the optimum bonding conditions for both optical glass bonding and image sensor clip bonding lo the flexible PCB. The bonding conditions, including sufficient bonding margins, were studied. Another bonding method is the flip chip bonding method for DSP (Digital Signal Processor) chip. A new AC\ulcorner was developed to enable the short resin curing time of 10 sec. The bonding mechanism of the resin curing method was evaluated using FEM analysis. By using these flip chip bonding techniques, small camera module was realized.

• ETRI Journal
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• v.36 no.2
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• pp.206-213
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• 2014

This paper presents a novel 90 GHz band 16-quadrature amplitude modulation (16-QAM) orthogonal frequency-division multiplexing (OFDM) communication system. The system can deliver 6 Gbps through six channels with a bandwidth of 3 GHz. Each channel occupies 500 MHz and delivers 1 Gbps using 16-QAM OFDM. To implement the system, a low-noise amplifier and an RF up/down conversion fourth-harmonically pumped mixer are implemented using a $0.1-{\mu}m$ gallium arsenide pseudomorphic high-electron-mobility transistor process. A polarization-division duplex architecture is used for full-duplex communication. In a digital modem, OFDM with 256-point fast Fourier transform and (255, 239) Reed-Solomon forward error correction codecs are used. The modem can compensate for a carrier-frequency offset of up to 50 ppm and a symbol rate offset of up to 1 ppm. Experiment results show that the system can achieve a bit error rate of $10^{-5}$ at a signal-to-noise ratio of about 19.8 dB.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.587-592
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• 2015

According to increase in the use of the LED, the demand for low power consumption LED display design of the controller block has increased. In this paper, the low power LED controller block was designed through the power source supply that leads adiabatic operation from constant current source circuit operated by digital signal control. The proposed circuit was implemented using a 0.35um CMOS process. and it demonstrated linear operation of the circuit. From the simulation result, the proposed circuit was evaluated with about 82% power consumption reduction effect in comparison with conventional LED controller block. This research is expected to be helpful for the low power operation and the solution for heat problem of LED display.