• YAKHAK HOEJI
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• v.36 no.4
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• pp.370-378
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• 1992

A simple and sensitive high performance liquid chromatographic method to quantitate ${\alpha}-keto$ acids in serum and urine was investigated. ${\alpha}-Keto$ acids react with 1,2-diamino-4,5-methylenedioxybenzene (DMB) in the presence of 2-mercapto-ethanol and sodium hydrogen sulfite to form highly fluorescent derivatives, substituted 6,7-methylenedioxyquinoxalinol. The derivatization procedure was performed in water bath at $100^{\circ}C$, and completed within 50 min. By the use of a reversed-phase column and multi-step gradient with two solvents, a mixture containing twelve of these derivatives were efficiently resolved within 35 minutes. The optimal wavelengh of the fluorescence detector are ${\lambda}_{ex}=364\;nm$ and ${\lambda}_{em}=445\;nm$. The quantitation of the individual ${\alpha}-Keto$ acids was reproducible with relative standard deviation of $3.0{\sim}7.9%$ and had a detection limits of $10{\sim}60$ fmol, except for p-hydroxyphenylpyruvic acid (960 fmol).

• Journal of Broadcast Engineering
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• v.24 no.3
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• pp.395-400
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• 2019

The CBS and the AEAS functionalities are defined in cellular systems and T-DMB systems, respectively. In the case that communication facilities are disabled in indoor environments, it is impossible for the residents to receive the emergency messages. In this paper, a novel collaborative technology of intelligent mobile robots is proposed, which relies on cooperative communications among the intelligent mobile robots. In order to improve the performance, the intelligent mobile robots exploit their location information. Simulation results confirm that the proposed method is very suitable for reliable emergency alert broadcast.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.525-528
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• 2009

This paper attempts to conceptually examine the potential of IPTV(Internet Protocol Television). First, this paper reviews the concept of a bridging telecommunication service and a gap-filling telecommunications service. Second, the current status of various emerging telecommunications services including mobile WiMax, called WiBro, and both satellite and terrestrial digital multimedia broadcasting service, called DMB are comprehensively analyzed. Based on those analysis, this paper analyzes whether IPTV is regared as a bridging telecommunications service or a gap-filling telecommunications service and examine the potential growth possibility of IPTV. Finally, the suggestions for policy makers are discussed.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.527-532
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• 2023

Brewer's spent grain (BSG) is a waste product of the beer industry, and γ-aminobutyric acid (GABA) is a physiologically active substance important for brain and neuron physiology. In this study, we used the bacterial strains Bacillus velezensis DMB06 and B. licheniformis 0DA23-1, respectively, to ferment BSG and produce GABA. The GABA biosynthesis pathways were identified through genomic analysis of the genomes of both strains. We then inoculated the strains into BSG to determine changes in pH, acidity, reducing sugar content, amino-type nitrogen content, and GABA production, which was approximately doubled in BSG inoculated with Bacillus compared to that in uninoculated BSG; however, no significant difference was observed in GABA production between the two bacterial strains. These results provide the experimental basis for expanding the use of BSG by demonstrating the potential gain in increasing GABA production from a waste resource.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.103-112
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• 2006

For recent innovation of If technology and the beginning of Digital Multimedia Broadcasting (DMB) service, it has been dramatically increased to setup TV system in a car for watching TV and receiving traffic Information. Watching TV while driving would distract a driver s cognitive and visual attention as eating food, operating the radio, using a cell phone. However, there is paucity of empirical researches and it is uncertain how watching TV in driving impacts on the driver's cognition in the concrete. Therefore, we surveyed domestic drivers on the attitude watching TV while driving as well as conducted experiments through a driving simulator. Especially, we recruited two groups of participants to explore the effects of watching TV on driving behavior. The result proved that the participants who watched TV while their driving had relatively narrower the attention span than the Participants who did not watch TV. Also, those who watched TV drove with less stability and more urgent operations of the brake and accelerator than those who did not watched TV Finally, we discussed limitations and implications of the study.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.452-462
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• 2008

In this paper, we address issues associated with the real-time implementation of the MPEG-1/2 Layer-II (or MUSICAM) and MPEG-4 ER-BSAC decoders for Digital Multimedia Broadcasting (DMB) on TMS320C64x+ that is a fixed-point DSP processor with a clock speed of 330 MHz. To achieve the real-time requirement, they should be optimized in different steps as follows. First of all, a C-code level optimization is performed by sharing the memory, adjusting data types, and unrolling loops. Next, an algorithm level optimization is carried out such as the reconfiguration of bitstream reading, the modification of synthesis filtering, and the rearrangement of the window coefficients for synthesis filtering. In addition, the C-code of a synthesis filtering module of the MPEG-1/2 Layer-II decoder is rewritten by using the linear assembly programming technique. This is because the synthesis filtering module requires the most processing time among all processing modules of the decoder. In order to show how the real-time implementation works, we obtain the percentage of the processing time for decoding and calculate a RMS value between the decoded audio signals by the reference MPEG decoder and its DSP version implemented in this paper. As a result, it is shown that the percentages of the processing time for the MPEG-1/2 Layer-II and MPEG-4 ER-BSAC decoders occupy less than 3% and 11% of the DSP clock cycles, respectively, and the RMS values of the MPEG-1/2 Layer-II and MPEG-4 ER-BSAC decoders implemented in this paper all satisfy the criterion of -77.01 dB which is defined by the MPEG standards.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5A
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• pp.482-489
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• 2010

In this paper we have proposed a new architecture of DQ-IRM(Double-Quadrature Image Rejection Mixer) for image rejection in the low-IF receiver. It consist of a frequency-tunable RF PPF(Poly Phase Filter) and the quadrature mixers. The conventional DQ-IRM generates the quadrature RF signals for the RF wide band at once. But the proposed DQ-IRM with the frequency-tuable RF PPF generates the quadrature RF signals for the narrow band of 2~3 channels bandwidth, which is partitioned from the RF wide band. We designed the CMOS RF tuner for T-DMB(Terrestrial Digital Multimedia Broadcasting) with the proposed 3rd DQ-IRM using a 0.18um CMOS technology and verified the performances of the designed receiver such as the image rejection ratio, the noise figure and the power consumption. The overall NF of the RF tuner is about 1.26 dB and the image reject ratio is about 51 dB. The power consumption is 55.8 mW at 1.8 V supply voltage. The chip area is $3.0{\times}2.5mm^2$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.4 s.95
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• pp.366-372
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• 2005

This paper presents analysis of a slot array antenna having a low side lobe level and high front-to-back ratio for a repeater system of a satellite DMB(Digital Multimedia Broadcasting) service. Antennas for this repeater system require a high gain and enough isolation to reduce interferences between signals in system. Therefore, it is necessary to suppress a side lobe level and to increase front-to-back ratio. Unlike a structure 134 by lossy microstrip lines, in this work a single cavity-backed slot antenna array using a single waveguide feed is proposed to obtain the reliability for high power handling and high radiation efficiency. The side lobe level and front-to-back ratio are enhanced with tapered array technique and an optimized vertical reflector. The measured side lobe levels in H- and E-plane are under $-33.24\;\cal{dB}$ and $-35.78\;\cal{dB}$, respectively. The front-to-back ratio over $37.84\;\cal{dB}$, and the peak gain of over $17\;\cal{dBi}$ are measured.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.253-256
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• 2009

This paper describes a core generator (FFT_Core_Gen) which generates Verilog HDL models of 8 different FFT/IFFT cores with $N=64{\times}2^k$($0{\leq}k{\leq}7$ for OFDM-based communication systems. The generated FFT/IFFT cores are based on in-place single memory architecture, and use a hybrid structure of radix-4 and radix-2 DIF algorithm to accommodate various FFT lengths. To achieve both memory reduction and the improved SQNR, a conditional scaling technique is adopted, which conditionally scales the intermediate results of each computational stage, and the internal data and twiddle factor has 14 bits. The generated FFT/IFFT cores have the SQNR of 58-dB for N=8,192 and 63-dB for N=64. The cores synthesized with a $0.35-{\mu}m$ CMOS standard cell library can operate with 75-MHz@3.3-V, and a 8,192-point FFT can be computed in $762.7-{\mu}s$, thus the cores satisfy the specifications of wireless LAN, DMB, and DVB systems.

• Journal of Broadcast Engineering
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• v.27 no.1
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• pp.80-90
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• 2022

Currently, the domestic early warning system is issued differently for each disaster, and is operated independently by relevant organizations from central government to local governments. Representative domestic disaster warning systems include disaster broadcasting using CBS(Cell Broadcasting Service) and DMB(Digital Multimedia Broadcasting) Automatic Emergency Alert Service, DITS(Disaster Information Transform System) transmitted and displayed on TV screens, automatic response system, automated rainfall warning system, and disaster message board. However, due to the difference in the method of issuing each emergency alert at the site of an emergency disaster, the alerts are issued at different times for each media, and the delivered content is also not integrated. If these systems are integrated, it is expected that damage to people's property and lives will be minimized by sharing and integrated management of disaster information such as voice, video, and data to comprehensively judge and make decisions about disaster situations. Therefore, in this study, we present a plan for the integration of the disaster warning system along with the analysis of the operation status of the domestic early warning system.