• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.331-340
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• 2006

In this Paper, we propose to extend the TSS-LS(Two-Step Search scheme with Linear search based Second step) scheme which was already proposed by the authors for coherent UWB(Ultra Wide Band) systems, to rapid and reliable acquisition of noncoherent UWB systems in multipath channels. The proposed noncoherent TSS-LS employing simple energy window banks utilizes two different thresholds and search windows to achieve fast acquisition. Furthermore, the linear search is adopted for the second step in the proposed scheme to correctly find the starting point in the range of effective delay spread of the multipath channels, and to obtain reliable BER(Bit Error Rate) performance of the noncoherent UWB systems. Simulation results with multipath channel models by IEEE 802.15.3a show that the proposed two-step search scheme can achieve significant reduction of the required mean acquisition time as compared to general search schemes. ]n addition, the proposed scheme achieves quite good BER performance for large signal-to-noise ratios, which is favorably comparable to the case of ideal perfect timing.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1995.04a
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• pp.93-108
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• 1995

SART(Search and Rescue Radar Transponder) is a radar transponder capable of operating in the 9GHz band which is one element of GMDSS. the fundamental function of the SART is to indicate its position. Thus it is so much available to assist SAR operation when an emergency and casualty occur at any sea area, In the thesis we designed manufactured each part of circuit to develop the advanced SART and configured to test the characteristics in many ways, As the results of detailed things we confirmed that the developed SART could be high possibility of production.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.373-376
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• 2001

This paper has been studied a real-time video frame data processing control that used the linear systolic array for motion estimation. The proposed data control processing provides to the input data into the multiple processor array unit(MPAU) from search area and reference block data. The proposed data control architecture has based on two slice band for input data processing. And it has no required external control logic blocks for input data as like reference block or search area data.

• Journal of the Korean Institute of Navigation
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• v.19 no.1
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• pp.17-32
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• 1995

SART(Search and Rescue Radar Transponder) is a radar transponder capable of operating in the 9GHz band, which is one element of GMDSS. The fundamental function of the SART is to indicate its position. Thus, it is so much available to assist SAR operation when an emergency and casualty occur at any sea area. In the thesis, we designed, manufactured each part of circuit to develop the advanced SART and configured to test the characteristics in many ways. As the result of detailed things, we confirmed that the developed SART could be high possibility of production.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1851-1854
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• 2003

This paper suggests an algorithm which can retrieval images using correlations between the region classification of spatial image and the wavelet transform even though the images are rotated in a ${\pm}$90 degree arc. Owing to this proposed method, it was confirmed from experiments that the search about the whole image is not processed and only a few amount of informations are saved by using the mathematical statistics from the block map and transformed band which is resulted from region classification, and by performing the image search based on these, the improvement of search speed and the efficient search can be done.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.685-697
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• 2017

In this paper, it is presented the result of design and fabrication for C-band solid state high power amplifier unit and components using in search radar. The solid state power amplifier(SSPA) assembly was fabricated using GaN(Gallium Nitride), which is semiconductor device, and the transmit signal output power of the solid state high power amplifier unit is generated by combining the transmit signal power of the solid state power amplifier configured in parallel through a design and fabricated waveguide type transmit signal combine assembler. Designed solid state high power amplifier unit demonstrated C-band 500 MHz bandwidth, maximum 10.5% duty cycle, transmit pulse width from $0.0{\mu}s{\sim}000{\mu}s$, and transmit signal power is 44.98 kW(76.53 dBm).

• Korean Journal of Remote Sensing
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• v.35 no.4
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• pp.535-544
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• 2019

This study demonstrated the ability of a Landsat-8 OLI multispectral data to identify and delineate hydrothermal alteration zones around auriferous prospects within the crystalline basement, North-western Nigeria. Remote sensing techniques have been widely used in lithological, structural discrimination and alteration rock delineation, and in general geological studies. Several artisanal mining activities for gold deposit occur in the surrounding areas within the basement complex and the search for new possible mineralized zones have heightened in recent times. Systematic Landsat-8 OLI data processing methods such as colour composite, band ratio and minimum noise fraction were used in this study. Colour composite of band 4, 3 and 2 was displayed in Red-Green-Blue colour image to distinguish lithologies. Band ratio ${\frac{4}{2}}$ image displayed in red was used to highlight ferric-ion bearing minerals(hematite, goethite, jarosite) associated with hydrothermal alteration, band ratio ${\frac{5}{6}}$ image displayed in green was used to highlight ferrous-ion bearing minerals such as olivine, amphibole and pyroxenes, while ratio ${\frac{6}{7}}$ image displayed in blue was used to highlight clay minerals, micas, talc-carbonates, etc. Band rationing helped to reduce the topographic illumination effect within images. The result of this study showed the distribution of the lithological units and the hydrothermal alteration zone which can be further prospected for mineral reserves.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.141-146
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• 2005

In this paper, we propose to extend the TSS-LS (Two-Step Search scheme with Linear search based Second step) scheme which was already proposed by the authors for coherent UWB (Ultra Wide Band) systems, to rapid and reliable acquisition of noncoherent UWB systems in multipath channels. The proposed noncoherent TSS-LS employing simple energy window banks utilizes two different thresholds and search windows to achieve fast acquisition. Furthermore, the linear search is adopted for the second step in the proposed scheme to correctly find the starting point in the range of effective delay spread of the multipath channels, and to obtain reliable BER (Bit Error Rate) performance of the noncoherent UWB systems. Simulation results show that the proposed TSS-LS can achieve significant reduction of the required mean acquisition time as compared to general search schemes. In addition, the proposed scheme achieves quite good BER performance, which is favorably comparable to the case of ideal perfect timing.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.80.2-80.2
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• 2021

Galactic young massive clusters are the ideal laboratories to study massive stellar evolution. Unfortunately, such objects are rare. Of particular interest are so-called Red Supergiant Clusters (RSGCs) that are currently only found toward the Scutum-Crux Galactic arm. Confirming their nature as RSGC is often not straight-fortward as distinguishing RSGs from AGB stars is still difficult even with high spectral resolution spectra. Here we report that broad band colors using 2MASS JHK and GAIA G band data can be useful in reducing the AGB contamination, thus providing selection criteria that effectively reveal the known RSGCs with negligible false positives. On the other hand, we suggest that RSGC4, one of the proposed RSGC candidates, may not be a cluster of RSGs as their colors are not compatible with our selection criteria. We discuss the nature of these stars together with our IGRINS spectroscopic observations. We also employ the same selection criteria to search for RSGC candidates in other parts of the plane, resulting in no prominent candidates.

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.373-374
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• 2008