• ETRI Journal
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• v.30 no.4
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• pp.495-505
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• 2008

This paper presents a parallel processing searcher structure for the initial synchronization of a direct sequence ultra-wideband (DS-UWB) system, which is suitable for the digital implementation of baseband functionalities with a 1.32 Gsample/s chip rate analog-to-digital converter. An initial timing acquisition algorithm and a data demodulation method are also studied. The proposed searcher effectively acquires initial symbol and frame timing during the preamble transmission period. A hardware efficient receiver structure using 24 parallel digital correlators for binary phase-shift keying DS-UWB transmission is presented. The proposed correlator structure operating at 55 MHz is shared for correlation operations in a searcher, a channel estimator, and the demodulator of a RAKE receiver. We also present a pseudo-random noise sequence generated with a primitive polynomial, $1+x^2+x^5$, for packet detection, automatic gain control, and initial timing acquisition. Simulation results show that the performance of the proposed parallel processing searcher employing the presented pseudo-random noise sequence outperforms that employing a preamble sequence in the IEEE 802.15.3a DS-UWB proposal.

• Journal of Life Science
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• v.8 no.2
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• pp.119-125
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• 1998

Column-purified double-stranded RNA binding factor (RBF) protein was tested for its binding affinity for the different forms of nucleic acids structure such as single-stranded(ss) and double-stranded(ds)RNA and ss- and dsDNA. The RBF protein was incubated with each of these nucleic acid structures in separate reactions and its comparative binding affnity was visualized by SDS-polyacrylamide gel electrophoresis. The RBF protein bound to the dsRNA molecule to form a tight RNA:protein complex in agreement with previous studies, but not to the other nucleic acid molecules confirming its distinctive affinity for the dsRNA structure. In phosphorylation assay in vito, the purified RBF protein significantly inhibited the autophosphorylation of the PKR derived from not only human but mouse source in the presence of poly(I):poly(C). It is suggesting that PKR vs. RBF is similarly under a competitive interaction among different eukaryotic organisms during protein synthesis.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.5-8
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• 2001

SSB(Single Sideband) modulation scheme is high bandwidth efficient method in the mobile communication system compared with present DSB(Double Sideband) modulation scheme. Using the othogonality between inphase PN code and Hilbert transformed quadrature PN code, we propose phase estimation structure that enables coherent demodulation in the reverse link basestation receiver Several system characteristics, bit error rate and phase error variance, are simulated and compared with balanced QPSK DS/CDMA system. To verify system performance, SSB/BPSK-DS/CDMA test board is implemented using FPGA chips.

• Molecules and Cells
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• v.45 no.1
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• pp.33-40
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• 2022

The various DNA-protein interactions associated with the expression of genetic information involve double-stranded DNA (dsDNA) bending. Due to the importance of the formation of the dsDNA bending structure, dsDNA bending properties have long been investigated in the biophysics field. Conventionally, DNA bendability is characterized by innate averaging data from bulk experiments. The advent of single-molecule methods, such as atomic force microscopy, optical and magnetic tweezers, tethered particle motion, and single-molecule fluorescence resonance energy transfer measurement, has provided valuable tools to investigate not only the static structures but also the dynamic properties of bent dsDNA. Here, we reviewed the single-molecule methods that have been used for investigating dsDNA bendability and new findings related to dsDNA bending. Single-molecule approaches are promising tools for revealing the unknown properties of dsDNA related to its bending, particularly in cells.

• Information and Communications Magazine
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• v.13 no.11
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• pp.181-191
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• 1996

In this paper we discuss narrow-band interference rejection schemes for spectrum overlay communications where direct sequence spread spectrum (DS/SS) communication system and narrow-band communication systems share the same frequency band. In this case, it is essential to reject the narrow-band signals to guarantee the performance of DS/SS system, while it is not necessarily required to reject the DS/SS signal to recover the narrow-band signal. We discuss several schemes such as time domain processing, frequency domain processing and exploiting the device characteristics to reduce the effect of narrow-band signal on DS/SS communication systems. Furthermore, we suggest a structure of tunable notch filter using gyrator that can easily be customized to ASIC.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.247-250
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• 2003

Mobile wire technology is a publicly available general purpose for Radio Frequency(RF) communication for short-range and point-to-multi point voice and data transfer. In this paper, we proposed a new technology of the synchronized frame structure which is based on the CDMA technique, and it's implemented into the VLSI design by FPGA. The developmental technique consists of an assigned coded type mobile communication equipments and available local mobile or wireless communication scheme quasi BT(Blue Tooth)'s functions as multiplexer or do-multiplexer for each other applications. We implement this architecture with special proposed frame structure in the local area network. Also, we expect the above proposed structure extend into the DS3 network architecture and applicable to the TE(Terminal Equipment) in the local communication area and the other one etc.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10A
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• pp.949-957
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• 2005

In this paper, the performances of a single-user DS-UWB system applying two simple proposed channel estimation schemes are introduced, according to the newly updated DS-UWB PHY Layer standard from IEEE P802.15.3a. The performances of error control coding, different combining schemes in selective Rake receiver for DS-UWB system are analyzed. Both of the two channel estimation schemes using data-independent structure work well in DS-UWB system with few pilot bits. For the purpose of channel estimation and reduces the number of pilot bits, we apply a pilot symbol spreaded with $2{^8}-1\;or\;2{^9}-1$ periods of m-sequence for different channel estimation schemes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1725-1731
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• 2010

In this paper, we proposed preamble structure and code acquisition method to improve code acquisition performance for DS-SS/TDMA packet communication systems. Proposed algorithm changes the short PN code position depending on the sub slot number. Proposed algorithm also saves position differences between short PN codes and position offsets between short PN codes and data starting position of the TDMA packet. By using the position difference table, proposed algorithm can find out exact data starting position even though some sub slots were defected. As a result of simulation, we concluded that proposed algorithm has at least 5dB gain compared to conventional method when same short PN code is used. Moreover, proposed algorithm shows same code acquisition performance only with 1/4 shortened short PN code compared to conventional method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.5
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• pp.493-502
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• 2009

In this paper, we compare the performance of initial timing acquisition in direct sequence ultra-wideband(DS-UWB) systems with different transmit pulse shaping filters through extensive computer simulations. Simulation results show that the timing acquisition performance of the DS-UWB system, whose chip rate is 1.32 Gchip/s, employing a rectangular transmit filter is similar to that employing a square root raised cosine(SRRC) filter with an interpolation factor of 4 in the realistic UWB channels(CM1 and CM3) as well as the additive white Gaussian noise(AWGN) channel. Additionally, we present both a 24-parallel digital correlator structure and a 24-parallel processing searcher operating at a 55 MHz system clock, and then briefly discuss the initial timing acquisition procedure. Because we can adopt an 1.32 Gsample/s digital-to-analog(D/A) converter and an 1.32 Gsample/s analog-to-digital(AID) converter in the DS-UWB system by employing the rectangular transmit filter, we have a realistic solution for the DS-UWB chipset development.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.1-12
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• 2016

This study is to make the liquid crystalline structure using sucrose distearate (Sucro-DS) emulsifier to create the hydrophilic type oil-in-water (O/W) emulsion, the droplets of the emulsion having a structure of a multi-lamellar structure. We have studied the physicochemical properties of Sucro-DS using those techniques. And it has been studied in the emulsion performance. In order to form the liquid crystalline structure applying 3 wt% of Sucro-DS, 5 wt% of glycerin, 5 wt% of squalane, 5 wt% of capric/caprylic triglyceride, 3wt% of cetostearyl alcohol, 1wt% of glyceryl mono-stearate, 78 wt% of pure water in mixture having the lamellar structure of stable multi-layer system was found to formed. By applying them, they were described how to create an unstable active material encapsulated cream. Further, the moisturizing cream was studied using this technique. It reported the results to the skin improvement effect by the human clinical trials. The pH range to produce a stable liquid crystal phase using a Sucro-DS was maintained in 5.2~7.5. In order to increase the stability of the liquid crystal, it was when behenyl alcohol containing 3 wt%, the hardness at this time was 13 kg/mm,min. Viscosity of the same amount was 25,000mPas/min. After a test for the effects of the emulsions, the concentration of 6 wt% Sucro-DS is that was appropriate, the particle size of the liquid crystal was 4~6mm. It was observed through a microscope analysis, reliability of the liquid crystal changes for 3 months was found to get stable at each $4^{\circ}C$, $25^{\circ}C$ and $45^{\circ}C$. In clinical trial test, before applying a moisturizing effect it was $13.4{\pm}7%$. Moisturizing cream liquid crystal was not formed in $14.5{\pm}5%$. Therefore, applying than ever before could see the moisture about 8.2% was improved. On the other hand, it was the moisturizing effect of the liquid cream is $19.2{\pm}7%$. The results showed that 43.3% improvement than that previously used. Applications fields, Sucro-DS emulsifier used liquid cream, lotion, eye cream and a variety of formulations can be developed, as well as the cosmetics industry is expected to be wide fields in the application of the external preparation for skin emulsion technology in the pharmaceutical industry and pharmaceutical industry.