• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3702-3707
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• 2009

In this paper, a new approximated MAP algorithm for soft bit decision from QAM symbols is proposed for Gray Coded QAM signals, based on the Max-Log-MAP and a Gray coded QAM signal can be separated into independent two Gray coded PAM signal, M-PAM on I axis with M symbols and N-PAM on Q axis with N symbols. The Max-Log-MAP used distance comparisons between symbols to get the soft bit decision instead of mathematical exponential or logarithm functions. But in accordance with the increase of the number of symbols, the number of comparisons also increase with high complexity. The proposed algorithm is used with the Euclidean distance and constituted with plain arithmetic functions, thus we can know intuitively that the algorithm has low implementing complexity comparing to conventional ones.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.226-228
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• 1998

The objective of this study was to observe the effects of potassium-cyanoethylstarch (K-CES), which is a natural polymer derivate,. and polyacrylamide (PAM), which is a synthetic polymer, on the growth of spinach under environment-controlled biotron. K-CES was made from tapioca starch, and introductions of acrylonitrile was confirmed by FT-IR. Water absorbing capacities (WAC) of K-CES and PAM were 37.6 and 47.8 times, respectively. WAC of PAM was slightly higher than K-CES, WAC of PAM m saline solutions were more reduced than those of K-CES. It was introduced that K-CES treatment was more effective than PAM in higher salinity of water and soil. Dry super absorptive polymers were put into solution, and the solution was applied to soil as an soil conditioner. Both amendments, K-CES and PAM, increased the vegetative growth of the spinach when applied at 0.1% of soil weight. In general, the most favorable results for early vegetative growth of the spinach came from the PAM treatment, followed by the K-CES treatment.

• Polymer(Korea)
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• v.27 no.4
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• pp.358-363
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• 2003

Dispersion polymerization of acrylamide was carried out in the media of ethyl alcohol/water mixtures using hydroxypropyl cellulose and ammonium persulfate as steric stabilizer and initiator, respectively. The effects of concentrations of initiator and steric stabilizer, amount of monomer, polymerization temperature, ethyl alcohol/water ratio, and purification of monomer and nitrogen purge on the particle size of the latices and molecular weight of the polymers were investigated. The average particle diameter increased with increasing concentration of initiator, water content in ethyl alcohol/water media, and polymerization temperature, but decreased with monomer and stabilizer concentrations. The viscosity average molecular weight increased with increasing concentrations of monomer, steric stabilizer, and water content in dispersion media, but decreased with initiator concentration and polymerization temperature. The PAM polymers prepared with the purified monomer and the nitrogen purging before the reaction showed the highest molecular weight. In this study, PAM latices of 0.5∼2.4 $\mu\textrm{m}$ with 20000∼335000 in M$\_$v/ were prepared and the resulting PAM latices were all dissolved in water instantly.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.923-932
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• 2012

The purpose of this study was to determine parameters of surface cover materials and evaluation the effects on runoff and sediment reductions with rice straw mat with PAM at watershed scale using the SWAT model. In this study, 1) regression equation of CN for rice straw mat + PAM using SCS curve number method was developed, 2) the USLE P factor, being able to reflect simulation of rice straw mat + PAM in the agricultural field, was estimated for various slope scenarios with VFSMOD-w. Then regression equation for CN and USLE P factor were used as input data in the SWAT model. Assuming rice straw mat + PAM is applied to radish and potato fields, occupying 24% of agricultural fields at the study watershed. Result of direct runoff without rice straw mat + PAM was $65,964,368\;m^3,$ with rice straw mat + PAM, direct runoff was $65,637,336\;m^3$, $327,031.8\;m^3$ reductions compared without it. Also, result of sediment without rice straw mat + PAM was 163,531 ton, with rice straw mat + PAM, sediment was 84,779 ton, 78,752 ton reduction compared without it. This analysis showed that about 48% sediment reductions would be expected with rice straw mat + PAM. As shown in this study, rice straw mat + PAM would be used as an efficient site-specific BMPs to reduce runoff and sediment discharge from field.

• The Journal of the Korea Contents Association
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• v.7 no.1
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• pp.116-123
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• 2007

This paper proposed a new amplitude width modulation for OLED data driver IC. The data driver controls brightness of OLED by adjusting amplitude and width of the data drive current pulse. There were two conventional methods; pulse amplitude modulation(PAM) and pulse width modulation(PWM). The PWM method suffered from lower light emitting time efficiency at low luminance signal. The PAM method suffered from large chip area using DACs for each column. The proposed method was aiming at accurately controlling of the current level by MSB data and light emitting efficiency by LSB data to improve the inefficiencies of the PAM and a PWM. The proposed AWM driver circuit implemented using $0.35-{\mu}m$ 3-poly 4-metal CMOS high voltage process. The simulation result shows the improvement in the accuracy of the gray level control even though the driver circuit is smaller than the PAM.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 1999.11a
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• pp.67-74
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• 1999

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.559-562
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• 2002

본 논문에서는 최근 제한적으로 사용이 승인된 UWB(초광대역： Ultra-Wideband) 통신을 AWGN 하에서 다중 접속을 고려하지 않은 단일 사용사일 경우로 가정시, M진 값이 변화함에 따른 에러율과 성능 개선 기법으로 BCH를 채용시의 에러율을 비교 분석하였다. 기존에 연구되어 오던 변조로 PAM(Pulse Amplitude Modulation)과 PPM(Pulse Position Modulation)방식을 비교하였으며 에러율 $10^{-6}$을 기준으로 M=2, 4일 경우 PAM이 PPM보다 약 E$_{b}$/N$_{o}$ =3~4［dB］, M=8 이상의 경우 PPM이 약 E$_{b}$/N$_{o}$ =9［dB］, M=16일 경우 약 E$_{b}$/N$_{o}$ =15［dB］정도 성능이 우수하였다. AWGN 채널 하에서 에러 정정 부호인 BCH(15,7)를 도입하였을 경우 에러율 $10^{-6}$을 기준으로 PAM방식은 약 E$_{b}$/N$_{o}$ 가 약 1［dB］, PPM 방식은 M=2, 4일 경우 약 E$_{b}$/N$_{o}$ =1~1.5［dB］정도 개선되었다.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.95-102
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• 2012

The objective of this research was to experimentally test the effect of rice straw mats on the reduction of runoff, sediment discharge and turbidity under a laboratory scale. We used the small runoff plots of 1 m ${\times}$ 1 m ${\times}$ 0.65 m ($L{\times}W{\times}H$) in size filled with loamy sand. Experimental treatments were bare (control), rice straw mat cover of straw mats + PAM + Gypsum (SPG), rice straw mats + Chaff + PAM + Gypsum (SCPG) and rice straw mats + Sawdust + PAM + Gypsum (SSPG); slope of 10 % or 20 %; and rainfall intensity of 30 mm/hr. Runoff volume and rate of covered plots were significantly lower than those of control plot. Average runoff rate of covered plots, slope of 10 % and 20 %, decreased 85.6 % and 72 % in respectively. Sediment reduction ratio was more than 99 % regardless of slope. The differences runoff and sediment discharge among different cover materials were not significant. It was also shown that even if runoff reduction by surface cover were low, sediment discharge reduction could be very significant and contribute to improve the water quality of streams in sloping agricultural regions. It was concluded that the use of straw mat and soil amendments (PAM and Gypsum) on sloping agricultural fields could reduce soil erosion and muddy runoff significantly and help improve the water quality and aquatic ecosystem in receiving waters. But mixing effect of PAM and Gypsum was minimal.

• Journal of Yeungnam Medical Science
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• v.30 no.1
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• pp.10-16
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• 2013

Background: Toll-like receptors (TLRs) are well-known pattern recognition receptors. Among the 13 TLRs, TLR2 is the most known receptor for immune response. It activates mitogen-activated protein kinases (MAPKs), which are counterbalanced by MAPK phosphatases [MKPs or dual-specificity phosphatases (DUSPs)]. However, the regulatory mechanism of DUSPs is still unclear. In this study, the effect of a TLR2 ligand (TLR2L, Pam3CSK4) on DUSP4 expression in Raw264.7 cells was demonstrated. Methods: A Raw264.7 mouse macrophage cell line was cultured in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum and 1% antibiotics (100 U/mL penicillin and 100 g/mL streptomycin) at $37^{\circ}C$ in 5% $CO_2$. TLR2L (Pam3CSK4)-mediated DUSP4 expressions were confirmed with RT-PCR and western blot analysis. In addition, the detection of reactive oxygen species (ROS) was measured with lucigenin assay. Results: Pam3CSK4 induced the expression of DUSP1, 2, 4, 5 and 16. The DUSP4 expression was also increased by TLR4 and 9 agonists (lipopolysaccharide and CpG ODN, respectively). Pam3CSK4 also induced ERK1/2 phosphorylation and ROS production, and the Pam3CSK4-induced DUSP4 expression was decreased by ERK1/2 (U0126) and ROS (DPI) inhibitors. U0126 suppressed the ROS production by Pam3CSK4. Conclusion: Pam3CSK4-mediated DUSP4 expression is regulated by ERK1/2 and ROS. This finding suggests the physiological importance of DUSP4 in TLR2-mediated immune response.

• Polymer(Korea)
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• v.25 no.4
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• pp.460-467
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• 2001

Inverse suspension polymerization of acrylamide (AM) in cyclohexane was carried out to study the effects of concentrations of sorbitan ester (Span) stabilizers and 2,2'-azobis (2-methyl propionamidine) dihydrochloride (AIBA) initiator, amount of monomer, shaking speed, and polymerization temperature on the particle size of the resulting poly (acrylamide) (PAM) beads and their molecular weights. It was found that the particle diameter. in general, decreased with increasing concentration of stabilizer, shaking speed, and water content in the aqueous phase, and with decreasing concentration of initiator and polymerization temperature. The average molecular weight of the resulting PAM beads was also found to increase with increasing concentrations of monomer and stabilizer, and also with decreasing concentration of initiator, polymerization temperature, and water content in the aqueous phase. In this study, PAM beads ranging 2 ~ 50 ${\mu}$m in diameter, with 8000000 ~ 12000000 in the weight average molecular weight were successfully prepared in almost 100% conversion.