• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.6
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• pp.18-26
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• 1999

This paper presents the architecture and design of a DSSS MODEM ASIC chip for wireless local area networks (WLAN). The implemented MODEM chip supports the DSSS physical layer specifications of the IEEE 802.11. The chip consits of a transmitter and a receiver which contain a CRC encoder/decoder, a differential encoder/decoder, a frequency offset compensator and a timing recovery circuit. The chip supports various data rates, i.e., 4,2 and 1Mbps and provides both DBPSK and DQPSK for data modulation. We have performed logic synthesis using the $SAMSUNG^{TM}$ $0.6{\mu}m$ gate array library and the implemented chip consists of 53,355 gates. The MODEM chip operates at 44MHz, the package type is 100-pin QFP and the power consumption is 1.2watt at 44MHz. The implemented MODEM architecture shows lower BER compared with the Harris HSP3824.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.35-42
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• 2007

The finite-field division can be applied to the elliptic curve cryptosystems. However, an efficient algorithm and the hardware design are required since the finite-field division takes much time to compute. In this paper, we propose a radix-4 systolic divider on $GF(2^m)$ with comparative area and performance. The algorithm of the proposed divide, is mathematically developed and new counter structure is proposed to map on low-cost systolic cells, so that the proposed systolic architecture is suitable for YLSI design. Compared to the bit-parallel, bit-serial and digit-serial dividers, the proposed divider has relatively effective high performance and low cost. We design and synthesis $GF(2^{193})$ finite-field divider using Dongbuanam $0.18{\mu}m$ standard cell library and the maximum clock frequency is 400MHz.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.3
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• pp.21-29
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• 2012

This paper presents optimized searching technique to improve the performance of H.264/AVC. By using the proposed forward and backward searching algorithm, redundant cycles of latency for data reordering can be removed. Furthermore, in order to reduce the total number of execution cycles of CAVLC encoder, early termination mode and two stage pipelined architecture are proposed. The experimental result shows that the proposed architecture needs only 36.0 cycles on average for each $16{\times}16$ macroblock encoding. The proposed architecture improves the performance by 57.8% than that of previous designs. The proposed CAVLC encoder was implemented using Verilog HDL and synthesized with Magnachip $0.18{\mu}m$ standard cell library. The synthesis result shows that the gate count is about 17K with 125Mhz clock frequency.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.52-60
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• 2008

The deblocking filter in the H.264/AVC video coding standard helps to reduce the blocking artifacts produced in the decoding process. But it consumes one third of the computational complexity in H.624/AVC decoder, which advocates an efficient design of a hardware accelerator for filtering. This paper proposes an architecture of deblocking filter using two filters and some registers for data reuse. Our architecture improves the throughput and minimize the number of external memory access by increasing data reuse. After initialization, two filters are able to perform filtering operation simultaneously. It takes only 96 clocks to complete filtering for one macroblock. We design and synthesis our architecture using Dongbuanam $0.18{\mu}m$ standard cell library and the maximum clock frequency is 200MHz.

• Environmental Mutagens and Carcinogens
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• v.16 no.1
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• pp.6-12
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• 1996

To investigate the clastogenicity of taxol and its precursor, 10-aleacetyl baccatin III, we performed chromosomal aberration assay with chinese hamster lung cells in vitro. The IC$_{50}$ values of taxol and 10-deacetyl baccatin III were determined as $1/16 \times 10^{-4}$ M (5.34 $\mu$g/ml) and $1 \times 10^{-2}$ M (560 $\mu$g/ml) in MTT assay, respectively. It means that the cytotoxicity of taxol revealed 100 times more cytotoxic than 10-deacetyl baccatin III in chinese hamster lung cell line. Nevertheless the strong positive genetic toxicity of taxol in the bone marrow micronucleus assay in vivo which was recently reported, we observed weak positive clastogenicity of taxoi only in the absence of metabolic activation system in the concentration ranges used in this experiment. Moreover, to clarify the involvement of metabolic fate of taxol because of its strong positive result in vivo, 10-deacetyl baccatin III which is a precursor in taxol synthesis, also subjected in chromosomal aberration assay in vitro. However, we observed no clastogenicity of 10-deacetyl baccatin III in this experiment. From above results, it was suggested that the esterification at C-13 appears to be relative for its genetic toxicity in chromosome aberration using chinese hamster lung cell in vitro.

• The Journal of Internal Korean Medicine
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• v.25 no.3
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• pp.482-491
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• 2004

Alzheimer's disease(AD) is a geriatric dementia that is widespread in old age. In the near future AD may be the biggest problem in public health service. Although a variety of oriental therapies in the study of Jimitang have been traditionally utilized for the treatment of AD, their pharmacological effects and active mechanisms have not been fully elucidated. This study in an investigation of effects of Jimitang on apoptotic cell death induced by CT105 overexpression in SK-N-SH neuroblastoma cell lines. DNA fragmentation, neurite outgrowth assay and LDH activity assay were examined. The regeneratory and inhibitory effects on Alzheimer's disease in pCT105-induced neuroblastoma cell lines by Jimitang water extract were examined. Findings from these experiments have shown that Jimitang inhibits the synthesis or activities of CT105, which has neurotoxicities and apoptotic activities in cell lines. In addition, pretreatment of $Jimitang(>50\;{\mu}g/mL\;for\;12\;hours)$ partially prevented CT(105)-induced cytotoxicity in SK-N-SH cell lines, and were inhibited by pretreatment. $Jimitang(>50\;{\mu}g/mL\;for\;12\;hours)$ repaired CT(105)-induced neurite outgrowth when SK-N-SH cell lines were transfected with CT(105). Results of this study show that. in the Jimitang group, the apoptosis in the nervous system in inhibited, the repair against the degerneration of neuroblastoma cells by CT105 expression is promoted. In addition, Jimitang was found to inhibit DNA fragmentation induced by CT105 overexpression, and promote neurite outgrowth. These findings suggest that Jimitang is beneficial for the treatment of AD.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.136-144
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• 1996

Polyacrylic super absorbent polymer(SAP) containing sorbitol was synthesized by inverse-suspension polymerization method. Sodium acrylate and acrylic acid were used as a monomer, ethylene glycol dimethacrylate(EGDMA) and glycerol polyglycidyl ether(GPGE) were used as a crosslinking agent, potassium persulfate(PPS) was used as an initiator, and cyclohexane was used as a solvent. Content of sorbitol was from 10mol% to 50mol% according to the mol ratio of acrylic acid monomer. The size distribution of the round shaped polymeric particle was $177{\sim}707{\mu}m$. Absorption amount of the polymer containing sorbitol was 785 to 1086 times of the polymer weight in distilled water, was 50 to 83 times in 0.9 % NaCl solution. Absorption and retention amount of the polymer were decreased with increasing the amount of sorbitol, but the polymer has an endothermic property which is +5 cal/g SAP.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.4 s.346
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• pp.38-48
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• 2006

In this paper, we developed a hardware architecture of Reed-Solomon RS(255,239) decoder for the DMB mobile terminals. The DMB provides multimedia broadcasting service to mobile terminals, hence it should have small dimension for low power and short decoding delay for real-time processing. We modified Euclid algorithm to apply it to the key equation solving which is the most complicated part of the RS decoding. We also designed a small finite field divider to avoid the use of large Inverse-ROM table, and it consumed 17 clocks. After synthesis with Synopsis on Samsung STD130 $0.18{\mu}m$ Standard Cell library, the Euclid block had 30,228 gates and consumed 288 clocks, which gave the 25% reduced area compared to other existing designs. The size of the entire RS decoder was about 45,000 gates.

• Archives of Pharmacal Research
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• v.26 no.4
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• pp.306-311
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• 2003

Soy, high dietary intake for the oriental population, is a main source of isoflavonoids. Sophoricoside (SOP) an isoflavone glycoside was isolated from immature fruits of Sophora japonica (Leguminosae family) and its inhibitory effect on chemical mediators involved in inflammatory response was investigated in this study. SOP inhibited the interleukin (IL)-6 bioactivity with an $IC_{50}$ value of 6.1 $\mu$M whereas it had no effects on IL-1$\beta$ and TNF-a bioactivities. SOP was identified as a selective inhibitor of cyclooxygenase (COX)-2 activity with an $IC_{50}$ value of 4.4 $\mu$ M, but did not show inhibitory effect on the synthesis of COX-2. However, SOP had no effect on the production of reactive oxygen species including superoxide anions and nitric oxide. These results revealed that in vitro anti-inflammatory action of SOP is significantly different from that of genistein known as a phytoestrogen of soy products. This experimental study has documented an importance of dietary soy isoflavonoids as multifunctional agents beneficial to human health, and will help to clarify protective mechanisms of SOP against inflammatory conditions.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.91-96
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• 2011

Deficiency of collagen regeneration, denaturalization of fibers, increased melanin synthesis and reactive oxygen species are important factors inducing deterioration of healthy skin function. They induce freckles and decrease in skin elasticity. Vitamin C, vitamin A and their derivatives have been used as cosmetic ingredients for improvement of these problems but they have various problems. We have been developing the various derivatives of these ingredients. In this study, we investigated whitening effect of 3-o-cetyl-L-ascorbic acid (VCCE), a new vitamin C derivative. The VCCE inhibited melanogenesis in a dose dependent manner(44 % at $20\;{\mu}g/mL $) and tyrosinase expression. For 8 weeks, we also investigated skin brightening effect of VCCE on pigmented spots in UV-irradiated human skin. In results, VCCE showed a statistically significant skin whitening effect by mechanical and visual evaluation. Taken together, our findings suggest that the VCCE has potential benefits as an active ingredient for whitening cosmetics.