• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.3
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• pp.289-295
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• 1998

The purpose of this paper is to propose an improvement method of BER for coded 16-QAM under Rayleigh fading channel. To overcome the BER degradation due to the fading under mobile communication, we apply delay modulation technique which is efficient to get both a coding gain and approximately one-half those needed by Manchester coding on bandwidth requirements. Especially, the delay modulation scheme is insensitive to the $180^{\circ}$phase ambiquity common to NRZ-L and Manchester coding schemes. From the computer simulation, BER performance of our scheme has achieved about 3.8 dB improvement of about $10^{-4}$, compared to Manchester coded 16-QAM.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1275-1282
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• 2012

This paper proposes the 16-channel LED Driver IC for Full color LED display system. The proposed LED driver IC in this paper can draw current independent of temperature and supply voltage in each channel. Current flow in the channel is configurable via an external resistor. LED brightness is adjusted by 12-Bit PWM(Pulse Width Modulation) and 8-Bit DC(Dot Correction). A real-time monitoring of IC temperature ($130^{\circ}C/150^{\circ}C$) and LED status (open/short) is provided by LED driver IC and the user can receive warning and get information on problems. A 16-channel LED driver IC is produced using 0.35 um BCD process and the size is $2.5mm{\times}2.5mm$. In this paper, channel current characteristic and channel current control function were measured in order to verify am embodied 16-channel LED driver IC by producing a single IC test board.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1085-1092
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• 2010

This paper describes the development of estimating equation for under 16 aged children's exposure to habitat's magnetic field for 24 hours by using particle swarm optimization(PSO) algorithm, which was carried out by using the measured database collected from the exposure survey to Korean habitat's magnetic field as to under 16 aged Korean students such as preschooler, children in elementary school, and children in middle school. Sex, age, residence type, size of habitation site, distance from power line, and power transmission voltage are used as the input data of estimating 24 hour's personal exposure to magnetic field. And distribution of 24 hour's personal exposure to magnetic field, exposure characteristic to magnetic field, and exposure characteristic to magnetic field according to special conditions, are analyzed for under 16 aged children.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.12
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• pp.1140-1144
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• 2012

In this paper, we propose a timing offset estimation scheme for initial ranging of IEEE 802.16e systems. The conventional scheme estimates the timing offset by using the cross-correlation between the local and received signals only. On the other hand, this paper proposes a timing offset estimation scheme with additional cross-correlations accumulated on the conventional cross-correlation. The additional cross-correlations are obtained by using the ranging signal with a repetitive structure. Numerical results show that the proposed scheme provides the better timing offset estimation performance compared with that of the conventional scheme.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1730-1736
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• 2015

This paper presents a 16-channel transimpedance amplifier (TIA) array implemented in a standard $0.18-{\mu}m$ CMOS technology for the applications of panoramic scan LADAR (PSL) systems. Since this array is the front-end circuits of the PSL systems to recover three dimensional image for unmanned vehicles, low-noise and high-gain characteristics are necessary. Thus, we propose a voltage-mode inverter TIA (I-TIA) array in this paper, of which measured results demonstrate that each channel of the array achieves $82-dB{\Omega}$ transimpedance gain, 565-MHz bandwidth for 0.5-pF photodiode capacitance, 6.7-pA/sqrt(Hz) noise current spectral density, and 33.8-mW power dissipation from a single 1.8-V supply. The measured eye-diagrams of the array confirm wide and clear eye-openings up to 1.3-Gb/s operations. Also, the optical pulse measurements estimate that the proposed 16-channel TIA array chip can detect signals within 20 meters away from the laser source. The whole chip occupies the area of $5.0{\times}1.1mm^2$ including I/O pads. For comparison, a current-mode 16-channel TIA array is also realized in the same $0.18-{\mu}m$ CMOS technology, which exploits regulated-cascode (RGC) input configuration. Measurements reveal that the I-TIA array achieves superior performance in optical pulse measurements.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.2043-2047
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• 2010

This study is to solve problems of depletion of RF bandwidth frequency, confusion possibility, security that current wireless communications system have and is to confirm possibility of applying next generation network. To solve problems of current wireless communications system, visible light communications system for power line communications using ATmega16 Microcontroller is was realized and receiver property was analyzed. PLC exclusive chip APLC-485MA, Microcontroller ATmega16, 5pi bulb type LED and high flux LED, visible light receiving sensor LLS08-A1 were used for transmitter and receiver. Performance was analyzed by designed program and an oscilloscope. It was showed average 20% improved receiver rate rather than bulb type LED in the case of high flux LED through voltage change rate on communication distance and LED type of distance between 10 to 50 cm. The blue LED showed the best performance among measured LED types with above 10% of voltage decreasing rate. But As it gradually becomes more distant, the precise date was difficult to obtain due to weak light. To overcome these sort of problems, specific values such as changing conditions and efficiency value relevant to light emitting parts and visible light receiving sensor should be calculated and continuous study and improvements should also be accomplished for the better communications condition.

• Journal of Microbiology
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• v.41 no.4
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• pp.312-319
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• 2003

In an attempt to develop a method for rapid and accurate identification of six Vibrio species that are clinically important and most frequently detected in Korea, 16S rDNA restriction fragment length polymorphism (RFLP) of Vibrio type strains, as well as environmental isolates obtained from the Korean coastal area, was analyzed using ten restriction endonucleases. Digestion of the 16S rDNA fragments amplified by polymerase chain reaction (PCR) with the enzymes gave rise to 2~6 restriction patterns for each digestion for 47 Vibrio strains and isolates. An additional 2~3 restriction patterns were observed for five reference species, including Escherichia coli, Aeromonas hydrophila, A. salmonicida, Photobacterium phosphoreum, and Plesiomonas shigelloides. A genetic distance tree based on RFLP of the bacterial species correlated well with that based on 16S rDNA sequences. The very small 16S rDNA sequence difference (0.1%) between V. alginolyticus and V. parahaemolyticus was resolved clearly by RFLP with a genetic distance of more than 2%. RFLP variation within a species was also detected in the cases of V. parahaemolyticus, V. proteolyticus, and V. vulnificus. According to the RFLP analysis, six Vibrio and five reference species were assigned to 12 genotypes. Using three restriction endonucleases to analyze RFLP proved sufficient to identify the six pathogenic Vibrio species.

• Bulletin of the Korean Chemical Society
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• v.20 no.11
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• pp.1335-1339
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• 1999

The function of 5S rRNA, a constituent of a large subunit of ribosome, is not clearly known yet. To identify RNA motifs interacting with 5S rRNA, and thereby to get an insight into the function of 5S rRNA in the ribosome, a SELEX (Systematic Evolution of Ligands by Exponential Enrichment) experiment was performed. RNA molecules binding to Escherichia coli 5S rRNA were selected from a 48-mer random sequence library through 12 rounds of selection, cloned, and sequenced. Two groups of the selected RNA molecules had the consensus sequences GCGG and GUGAAA, respectively, which are present in the segment, G688 through A696, of E. coli 16S rRNA. The gel mobility shift assay showed that 5S rRNA interacted with the 16S rRNA fragment containing the GCGG and GUGAAA sequences. The enzymatic protection experiment shows that the A29CCUGA34 and G51AAGUG56 sequences of 5S rRNA and the C680AGG683 and G688CGG691 sequences of the 16S rRNA fragment are involved in the interaction between the two RNA molecules. On the basis of this observation, we suggest that 5S rRNA and 16S rRNA play a role for the association of two ribosomal subunits.

• YAKHAK HOEJI
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• v.56 no.6
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• pp.395-400
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• 2012

To investigate the possibility of development as a whitening agent using arctigenin, we measured DPPH assay, NBT/XO assay, intracellular ROS scavenging assay, tyrosinase assay and MSH-induced melanin production in B16 melanoma cells. Arctigenin dose-dependently had anti-oxidant activity in DPPH, NBT/XO and intracellular ROS assay. Although arctigenin did not inhibit purified tyrosinase activity, it dose-dependently inhibited tyrosinase activity and melanin production in B16 melanoma cells stimulated by $1{\mu}M$ ${\alpha}$-MSH. In particular, arctigenin at a concentration $100{\mu}M$ inhibited ${\alpha}$-MSH-stimulated tyrosinase activity and melanin production by $50.9{\pm}2.9%$ and $69.0{\pm}6.5%$ respectively. And typical tyrosinase inhibitor, arbutin, inhibited $57.7{\pm}2.9%$ and $65.1{\pm}5.0%$ respectively. Such an similar inhibitory effect of arctigenin and arbutin in B16 melanoma cells may be due to the inhibition of MSH signal pathway rather than the direct inhibition of tyrosinase. Therefore, these results suggest that arctigenin may be useful for the development as whitening agents.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.418-423
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• 2019

The purpose of this study was to determine how the different number of channels of coils were related in the perceived signal intensity under identical parameters and area. Dedicated knee phantoms were scanned consecutively using both of the 16-channel and 8-channel knee coils. The T1 weighted and T2 weighted sequences were acquired using both coils to compare the signal intensities according to the number of channels. As a result, the 16-channel knee coils outperformed the 8-channel knee coils and the signal intensity was significantly increased in both of the T1 and T2 weighted images with the 16-channel coil. In conclusion, it is considered that better signal intensities and more clinical utility can be provided, when coils with more number of channels are used rather than using the coils with smaller number of channels.