• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.109-116
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• 2006

This paper presents a real time distance measuring device using a W-band linear frequency modulated continuous wave(FMCW) radar and TMS320C6701 digital signal processor(DSP). We used FFT operation for measuring distance with the beat signals and the results of FFT could be converted to distance with ease. We presented how to implement a real time miniaturized hardware system including network protocols using a single DSP core. Also how to control the modulation signal of FMCW system to compensate the VCO nonlinearity using the Time Gating control of DSP is presented. We have shown that the proposed system has good performances for measuring distance in real time via outdoor environment experiments.

• Electronics and Telecommunications Trends
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• v.32 no.6
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• pp.66-72
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• 2017

The frequency range of a radio wave is from 3kHz to 300GHz, and radio technologies use this range to improve the quality of human lives. Radio technologies have entered a new phase of communication. The core infrastructure used as the basis for technologies leading the fourth industrial evolution, such as artificial intelligence, the Internet of Things, autonomous cars/drones, augmented reality, robots, and remote medical diagnoses, is the 5G network. The 5G network enables transmitting and receiving large amounts of data at very high speed. In particular, application technologies with artificial intelligence have been studied, including radar, wireless charging, electromagnetic devices and their effects on humans, EMI/EMC, and microwave imaging. In this study, we present a future radio technology that is needed to prepare for the upcoming industrial revolution and digital transformation.

• Korean Journal of Computational Design and Engineering
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• v.14 no.1
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• pp.10-17
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• 2009

Surface detection and parameter estimation in point cloud is a relevant subject in CAD/CAM, reverse engineering, computer vision, coordinate metrology and digital factory. In this paper we present a software for a fully automatic surface detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting, which work interactively. Our newly developed algorithms for orthogonal distance fitting(ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. We demonstrate the performance of the software on a variety of point clouds generated by laser radar, computer tomography, and stripe-projection method.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.205-211
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• 1997

For the prediction of multi-site rainfall with radar data and ground meteorological data, a rainfall prediction model was proposed, which uses the neural network theory, a kind of artifical Intelligence technique. The Input layer of the prediction model was constructed with current ground meteorological data, their variation, moving vectors of rain- fall field and digital terrain of the measuring site, and the output layer was constructed with the predicted rainfall up to 3 hours. In the application of the prediction model to the Pyungchang river basin, the learning results of neural network prediction model showed more Improved results than the parameter estimation results of an existing physically based model. And the proposed model comparisonally well predicted the time distribution of ralnfall.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.71-78
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• 2007

We suggest a multi-path propagation analysis method using DTM(Digital Terrain Map). Generally, the total signal strength at a target is calculated by adding the field propagated in free space and the field reflected from the ground surface. In this paper, we also consider the vertical reflections associated with the vertical surfaces such as precipitous cliffs and electricity pylons in the mountain area. In addition, we primarily take account the main slope of the ground surface to improve the accuracy of the total field density at the target.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.4
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• pp.97-104
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• 2010

In this paper, we provide an embedded type non-contact bio-radar heart and respiration rate monitoring system. We implemented the rate finding algorithm into the embedded system. The high-speed and reliable real-time signal processor is then tested. To avoid null-point data loss problem, we applied quadrature demodulation. Among several other combining techniques, we suggest arctangent demodulation for quadrature channel combining and DSP is used for real-time signal processing. We also suggest DC-offset compensation technique to preserve the wanted DC components of the IQ signals for accurate demodulation while keeping the dynamic range of the ADC lower. Using Texas Instrument C6711 series DSP and external 12Bit ADC, we implemented proper elliptic digital filter and autocorrelation detection algorithm for robust commercial hand held device.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.12
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• pp.1243-1251
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• 2009

This paper presents design and test results of X-Band Transmit/Receive(T/R) module for active phased-array radar. Active phased array radars typically require solid state T/R modules with high output power, low noise figure, high Third Order Intercept(TOI), and sufficient gain in both transmit and receive. The output power of the module is 9 watts over a wide bandwidth. The noise figure is as low as 2.8 dB. Phase and amplitude are controlled by the 6-bit phase shifter and 5-bit attenuator, respectively. Highly integrated T/R module is achieved by using LTCC(Low Temperature Co-fired Ceramic) multiple layer substrate. The module incorporates a compact digital interface, requires only three supply voltages.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.738-746
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• 2016

As the trend of future war has been changed to network centric warfare, tactical data link should be needed for fast and accurate situation awareness. Nowadays, Korean air force conducts military operations by using aircrafts equipped with Link-16. The Link-16 can conduct multiple mission at the same time because it supports multi-net capability. Due to lack of frequency resource, the way to share the frequency with other systems has been studied and using L band with radar is considered as one of the candidates bands. However, the data link can be affected by the interference from radars when it shares the L-band because the L-band in Korea is already assigned to long-range detection radars. In this paper, we evaluate operational possibilities of tactical data link in the L-band based on Link-16.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.51-57
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• 2017

In this paper, we designed a frequency synthesizer using DDS (Direct Digital Synthesizer) for Ka-band compact Radar. DDS is applied to generate various waveform and to cover high-speed frequency sweep. In order to reduce size, waveform generator and Ka band frequency up-converter are integrated in one module. Proposed frequency synthesizer provides LFM(Linear Frequency Modulation) waveform and Phase modulated FMCW (Frequency Modulation Continuous Wave) waveform. It is observed that fabricated synthesizer performs $0.191{\mu}sec$ frequency switching time and -89.16 dBc/Hz phase noise at offset 1 kHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.143-148
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• 2013

This paper study about multi-beam for ditection of arrival estimation in wireless system. estimate a direction of arrival of target in multi input-output array antennas system. Beam steering method are divided by beam steering method of elevation angle or beam forming method, stack beam steering, frequency steering, phase steering radar and digital beam forming radar. Proposed algorithm is combined SVD method and antenna weight error compensation method with phase and amplitude compensation to effectivity beam steering. Through simulation, we were analysis of performance that general algorithm and proposed target estimation algorithm in this paper. It was proved to improved proposal algorithm than general algorithm in target direction of arrival estimation.