• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.205-208
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• 2008

Sulfonated polySEBS and sulfonated PS were synthesized by sulfonation at the aromatic group of polySEBS and PS. Novel sulfonated polySEBS/sulfonated PS blending films for the ion exchange membrane of polymer electrolyte fuel cell were prepared from these sulfonated polymers. The proton conductivities of these blending films were varied in $10^{-2}{\sim}10^{-3}S/cm$ with the blending ratio of sulfonated polySEBS/sulfonated PS. Especially, the film prepared from the addition of the sulfonated PS (0.5 g) in the sulfonated polySEBS (10.0 g) has the best proton conductivity (0.07 S/cm) with ion exchange capacity (0.75 meq/g) and water uptake (25%).

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.116-121
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• 1996

Antisense oligonucleotides seem to provide a promising new tool for the therapy. Choi et al. (1995) reported antisense phosphorothioate oligonucleotides (PS-ODN, 25 mer) complementary to TGF-.betha. mRNA designed for scar formation inhibitor to eliminate scars, which was caused by undesired collagen deposition due to overexpression of TGF-.betha., in wounded skin. PS-ODN were evaluated in vitro for skin penetration using normal and tape-stripped damaged rat skin. The in vitro skin transports were carried out with partially modified PS-ODN (6S) and fully modified PS-ODN (25S). The cumulative amount of PS-ODN (6S) penetrated through normal rat skin was $0.234{\pm}0.041{\mu}g/cm^2$ and that of tape-stripped damaged rat skin was $1.077{\pm}0.301{\mu}g/cm^2$ over 8 hrs. PS-ODN (25S) can not be found in receptor medium through normal skin due to high molecular weight (Mol.Wt.=8,000) and polyanionic charge. However, the cumulative amount of PS-ODN (25S) penetrated across damaged rat skin in PBS was $0.340{\pm}0.296{\mu}g/cm^2$ over 8 hrs. The absense of dermis raised the cumulative amount of PS-ODN (6S) penetrated through rat skin. And the fluxes of PS-ODN (6S) and PSODN (25S) at 8hrs across damaged rat skin were $134.63{\pm}37.67{\mu}g/cm^2$ h, and $42.50{\pm}36.95ng/cm^2$ h, respectively. While PS-ODN (25S) was stable in 10% heat inactivated fetal bovine serum (FBS) during 24 hrs, PS-ODN (6S) was less stable than PS-ODN (25S), but was markedly stable than unmodified phosphodiester. It is suggested that the cumulative amount of PS-ODN (6S) penetrated through damaged rat skin is larger than that of PS-ODN (25S) since the former is easier to degrade by nuclease than the latter and then is apt to penetrate into skin. Thus, PS-ODN represents a logical candidate for further evaluation due to the potential for delivery into the wounded skin.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.05a
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• pp.219-219
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• 2017

This study aims at examining each firm's decision-makings of complex product and system (hereafter CoPS) innovation strategy, so that it tries to reveal the nature and role of CoPS innovations strategy. And it designed a comparative case study along with qualitative methods, by having two mobile operators' digital rights management (hereafter DRM) innovation in South Korea's digital music service industry. Through literature review, this study formulated three research propositions: (i) Each firm's decision-makings of CoPS innovations strategy are analytical negotiation process among economic actors in an industry; (ii) Each firm's market power originated from its market share from the installed base through network effect and switching cost influence decision-makings of CoPS innovation strategies; (iii) Each firm's decision-makings of different CoPS innovation strategies are related to their intension of achieving better market power, consequently dominant design. Through empirical examination of two mobile operators' decision-makings of DRM innovation strategy, this study empirically verified three research propositions.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.173-177
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• 1996

The Pneumococcus, Streptococcus pneumoniae, has an ample polysaccharide (PS) capsule that is highly antigenic and is the main virulence factor of the organism. The capsular PS is the source of PS vaccine. This investigation was undertaken to optimize the culture conditions for the production of capsular PS by type 4 pneumococcus. Among several culture media, brain heart infusion (BHI) and Casitone based medium were found to support luxuriant growth of pneumococcus type 4 at the same level. Therefore in this study, the Casitone based medium was used to study optimization of the culture condition because of BHI broth's high cost and complex nature. The phase of growth which accomodated maximum PS production was exponential phase. Concentrations of glucose greater than 0.8% did not enhance growth or PS production. Substitution of nitrogen sources with other resources or supplementation of various concentrations of metal ion (with the exception of calcium, copper, and magnesium ions) had adverse effects on growth and PS production. On the other hand, low level aeration and supplementation of 3 mg/l concentration of asparagine, phenylalanine, or threonine were beneficial for increased PS production. The synergistic effect of all the favorable conditions observed in pneumococcal growth assays provided a two-fold cumulative increase in capsular PS production.

• Food Science of Animal Resources
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• v.20 no.3
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• pp.231-235
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• 2000

원유에 존재하는 Ps. fluorescens의 균수를 신속하게 측정하기 위한 Inhibition Enzyme Linked Immunosorbant Assay (ELSIA)를 개발하기 위해 Ps, fluorescens(KCTC 2344)을 산란계에 접종하여 Ps.fluorescens에 대한 anti-Ps. fluorescens IgY 항체를 생산하고 그 항체의 역기를 ELISA로 측정한 결과 32일까지 항체 역가가 증가하였으며, 분리된 IgY 항체의 titer는 1:128,000으로 나타났다. Anti-Ps.fluorescens IgY 항체에대한 교차반응을 조사한 결과 그람양성균 Lactococcus faecalis, Staphylococcus aureus 뿐만 아니라 그람음성 균인 Achrombacter sal-monisida, Escherichia coil와도 교차반응을 거의 하지 않는 것으로 나타났다. Anti-Ps. fluo-rescens IgY 항체를 가지고 Inhibition ELISA 방법으로 Ps. fluorescens 균수를 신속한 측정할 수 있는 표준곡선을 작성한 결과 Ps. fluorescens균을 5.0$\times$$10^4$cfu/ml부터 5.0$\times$$10^{8}$cfu/ml 측정할 수 있는 것으로 나타났다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.186-186
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• 1996

Streptococcus pneumoniae (pneumococcus), the most common cause of bacterial pneumonia, has an ample polysaccharide(PS) capsule that is highly antigenic and is the source of PS vaccine. This investigation was undertaken to optimize the culture conditions for the production of capsular PS by type 1 pneumococcus. Among several culture media, brain heart infusion (BHI) and Casitone based media were found to support luxuriant growth of pneumococcus type 1 at the same level. Because BHI medium is rather expensive and more complex than the Casitone based media, the Casitone based media was used to study optimization of the culture condition. The phase of growth which accomodated maximum PS production was logarithmic phase. Concentrations of glucose greater than 0.2% did not enhance growth or PS production. Substitution of nitrogen sources with other resources or supplemention of various concentrations of metal ion (with the exception of calcium ion) had adverse effects on growth and PS production. On the other hand, low level aeration was beneficial for increased PS production. Addition of 3 mg/I concentration of methionine, phenylalanine, and threonine were found to enhance growth and PS production. The synergistic effect of all the favorable conditions observed in pneumococcal growth assays provided a two-fold cumulative increase in capsular PS production.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.89-99
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• 2005

HPI system provides 1-3 Mbps data transmission speed to terminals moving up to 60 km/sec. Since HPI supports rtPS, nrtPS, and BE services requiring different QoS, it needs an efficient scheduling method based on those different QoSs. This paper suggests an uplink scheduling method which gives priority to services in the order of rtPS, nrtPS and BE services but which reserves some bandwidth for the low priority services before it allocates the bandwidth to higher priority services. Simulation results show that it can improve the uplink performance by reserving mean transmission rate to each nrtPS terminal and by reserving bandwidth, which amounts to about 1.5 times the mean transmission rate of the whole BE terminals, to the whole BE terminals.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.783-787
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• 2008

IEEE 802.16/WiBro, one of the representative Broadband Wireless Access (BWA) systems, defines QoS negotiation between BS and SS and five service classes to guarantee QoS for flows. The five service classes are UGS, ertPS, rtPS, nrtPS, and BE, but the standard does not define how to provide services to flows according to the service classes. Existing research works have been studied about the scheduler architecture to effectively utilize the IEEE 802.16/WiBro systems. These works use the original packet scheduling algorithm for service classes. However, it is necessary to consider bandwidth allocation mechanisms in scheduling algorithms since bandwidth allocation mechanisms are different according to service classes. Especially, bandwidth allocation mechanisms should be considered for the scheduling of rtPS class since rtPS class uses the polling mechanism that takes time to allocate bandwidth and has the minimum latency constraint. Therefore, we propose two stage dropping scheme for rtPS class that is sensitive to latency, and thus it reduces the wasted resources and provides efficient service to rtPS class.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.971-980
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• 2013

System performance improvement through the concentrated residual dispersion per span (RDPS) in special transmission fiber spans in optical transmission links with dispersion management (DM) for wavelength division multiplexed (WDM) transmission is investigated through the comparison with the performance in optical transmission links with uniform RDPS in every fiber spans. It is confirmed that, in optical links with RDPS of 0 ps/nm uniformly distributed in the rest fiber spans, if RDPS of 300 ps/nm and 1,320 ps/nm are concentrated in 5th-13th fiber spans and 6th-13th fiber spans, respectively, then the best performance is obtained. It is also confirmed that optimal net residual dispersion (NRD) controlled by precompensation and postcompensation are 10 ps/nm and -10 ps/nm, respectively, in all two cases, and the effective launching power range below 1 dB eye opening penalty (EOP) in the concentrated RDPS of 300 ps/nm and 1,320 ps/nm are improved by 2 dB and 6 dB than optical transmission links with the uniformly distributed RDPS, respectively.

• Polymer(Korea)
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• v.27 no.6
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• pp.603-608
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• 2003

Syndiotactic polystyrene (s-PS) presents a very complex polymorphic behavior depending on the sample preparation history and exhibits a solid-solid phase transition. Each different polymorphic structures of the s-PS sample were prepared by annealing the samples from room temperature to 220 $^{\circ}C$. The structural changes induced by annealing were investigated using FTIR and FT-Raman spectroscopy. Although the crystallization kinetics of s-PS are difficult to investigate with DSC due to its fast crystallization rate, it was possible to determine crystallinity changes in the s-PS sample using infrared characteristic peaks with Beer-Lambert's law.