• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.348-354
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• 1994

Chitin and chitosan samples prepared from crab's shells under different conditions were compared for their physicochemical properties; and functionality in gastrointestinal tract by in vitro test. Their bulk density was in the range of $127{\sim}208\;mg/ml$, and their viscosity was $80{\sim}581\;cP$ in 0.1 chitin and $80{\sim}3,670\;cP$ in 0.5% chitosan solution, showing a wide variation. The degree of deacetylation in chitosan samples as determined by IR spectral analysis was relatively high, showing $81{\sim}93%$. At the same alkali concentration and reaction temperature, a longer reaction period gave an increased degree of deacetylation and lower viscosity. The water holding capacity of chitic substance became greater at higher soaking temperature; chitosan D at $37^{\circ}C$ showed the greatest value. Chitic substance with lower bulk density showed the higher water holding capacity. The retardation effect toward glucose absorption was higher in critic substances of lower density and higher water holding capacity; chitosan D showed the highest value of 38%. The retardation index toward bile acid absorption after 1 hour dialysis was $15{\sim}34%$ in chitic substances, 39% in pectin and 9% in cellulose. The retarding effect showed the highest value of 34% in chitosan D at 3% concentration.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.3 s.18
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• pp.73-82
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• 2005

The scheme for the conveyance increasement of urban river is presented in this study. For the use of the lower part of the road paralleled to urban river as a conveyance, the 2-dimensional flood flow between main channel and added conveyance section is analyzed by mathematical model SMS(2-D simulation model). The result of the HEC-RAS(1-D simulation model) is used to calibrate the parameters of SMS. New scheme is applied to the Cheonggeyecheon Restoration Project. The capacity of flood flow between main channel and added conveyance is simulated for 50, 80, 200 year frequency flood and suitable size of pathway is proposed.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.922-928
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• 1997

The conformational transition of poly(L-proline) (PLP), Form Ⅱ → Form Ⅰ and the intermolecular aggregation of the product, Form Ⅰ, during and after the transition in water-propanol (1:7, 1:9, 1:15.7, and 1:29 v/v) were studied. For the study, the viscosity change and excess light scattering intensity were measured in the course of the transition which was determined by the Form Ⅰ fraction, fI of the sample solution. For the PLP sample of molecular weight Mv=31,000 the experimental results show that the reaction course is roughly divided into three regions: in the first region [fI=0.27 to 0.40 (- [α]D=400 to 330)], the conformational change of Form Ⅱ → Form Ⅰ occurs with decrease of viscosity, in the second region [fI=0.40 to 0.80 (- [α]D=330 to 120)], a partial side-by-side (p-S-S) type aggregation in which Form Ⅰ blocks interact with each other, which induces the increase of viscosity, starts to occur, and in the third region [fI=0.80 to 1.00 (- [α]D=120 to 15)], a side-by-side type (raft like) aggregation of Form Ⅰ or an end-to-end (E-E) type aggregation occurs according to the solvent situation, i.e., in a water-rich medium [water-propanol (1:9 or 1:7 v/v)], the (S-S) type aggregation with a gross decrease in viscosity occurs while in a water-poor medium [water-propanol (1:29 or 1:15.7 v/v), the (E-E) type aggregation with a large increase in viscosity occurs. The (S-S) type aggregation was promoted at high temperatures. Based on the structure of PLP, a reasonable mechanism for the (p-S-S) and (S-S) aggregation which occurs with the transition of Form Ⅱ → Form Ⅰ is considered. The suggested mechanism was also supported by the result of chain length effect of PLP for the aggregation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.80-84
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• 2013

The EU in order to surpass the United States in the world economy have tried several aspects. Economic growth is possible through the technological competitiveness of this industry, and also through the development of industrial technology and employment. Such EU Commission has taken several support policies in order to raise the R & D capabilities. Non-EU member countries, Korea, R & D pipe central incisor see support for the policy proposal evaluation for women is important. The aim of this paper is to analyze the proposal evaluation process of the EU commission for R&D projects. I argue that the EU's methode of proposal evaluation for EU R&D consists of five stages: expert briefings, proposals for individual assessment, consensus and finally a panel evaluation. The main features of the EU's R&D evaluation process for proposals are experts and panel evaluation. The Korean government could select, operate and manage experts for the EU's R&D evaluation. That would lead to a higher rate of success for Korean proposals in the EU.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.623-632
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• 1996

The reactivity ratios, melting temperature and polymer morphology in propylene/butene-1 and propylene/hexene-1 copolymerization reactions were studied by examining comonomer compositions of resulting polymers. The catalysts used here are different in their supports which are silica(catalyst I) and magnesium(catalyst II). As the content of comonomer(butene-1 and hexene-1) increased in the copolymer, the melting temperature of the copolymer decreased. The morphology of polymer was amorphous in the range of comonomer(butene-1) composition over 40% in the propylene/butene-1 copolymerization and comonomer(hexene-1) composition over 80% in the propylene/hexene-1 copolymerization. The reactivity ratios were obtained by the Fineman-Ross and Kelen-$T{\ddot{u}}d{\tilde{o}}s$ methods.

• Journal of Advanced Navigation Technology
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• v.24 no.1
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• pp.28-36
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• 2020

Korea augmentation satellite system (KASS) is the Korean satellite based augmentation system (SBAS) developed by ministry of land, infrastructure, and transport (MOLIT) since 2014. Since KASS is the safety critical system that can affect to the safety of airplane, the software of KASS is developed according to the DO178B software level induced from safety analysis. In case of KASS control station (KCS), most of the software of KCS get assigned software level E in DO178B. In that case, ECSS-Q-ST-80C category D is assigned as a software product assurance standard. In this paper, the software related standard ECSS-E-ST-40C, ECSS-Q-HB-80-04A are analyzed to satisfy ECSS-Q-ST-80C and as a result the software product assurance activities regarding software life cycle and the software quality model, metric is proposed for the product assurance of the KCS software.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.841-848
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• 2016

In this paper, a microstrip-fed dual-band monopole antenna with DGS(: Defected Ground System) for WLAN(: Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a microstrip-fed structure, and composed of two strip lines and DGS structure and then designed in order to get dual band characteristics. We used the simulator, Ansoft's High Frequency Structure Simulator(: HFSS) and carried out simulation about parameters W2, L10, W3, and DGS to get the optimized parameters. The proposed antenna is made of $21.0{\times}36.0{\times}1.6mm3$ and is fabricated on the permittivity 4.4 FR-4 substrate. The experiment results are shown that the proposed antenna obtained the -10 dB impedance bandwidth 700 MHz(2.10~2.80 GHz) and 1,780 MHz(5.02~6.80 GHz) covering the WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required dual-band(2.4GHz band/5.0GHz band), respectively.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.878-884
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• 1995

In order to use whey lactose in alcohol fermentation, we investigated fermentation conditions of Saccharomyces cerevisiae and Kluyveromyces fragilis in lactose-hydrolyzed whey with ${\beta}-D-galactosidase$. and optimum conditions of the above two yeasts through oxygen regulation by Pasteur effect which is the characteristic of the yeasts were determined. In addition, optimum condition for application of fermented whey in Tak-ju process was also examined. With 0.7% ${\beta}-D-galactosidase$, 93% lactose was hydrolyzed at pH 6.5 in 30 minutes. Because S. cerevisiae is unable to ferment galactose, the production of ethanol by S. cerevisiae was lower than that of K. fragilis in lactose-hydrolyzed whey. But ethanol productivity by S. cerevisiae was higher than that by K. fragilis in glucose added whey. In fermentation with oxygen regulation and addition of 60 g/l glucose, the ethanol productivity of K. fragilis and S. cerevisiae were 18.9 g/l (11.8% increase) and 43.5 g/l (22.1% increase), respectively. It appeared that the ethanol productivity of S. cerevisiae was higher than thst of K. fragilis under the above conditions. In ethanol fermentation added rice starch, Aspegillus oryzae hydrolyzed 80% of starch in 60 hours, and the production of ethanol was 80.2 g/l

• The Korean Journal of Nuclear Medicine
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• v.31 no.4
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• pp.421-426
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• 1997

We evaluated the in vivo kinetics, distribution, and pharmacology of N-(4-[$^{18}F$]fluoromethylbenzyl)spiperone ([$^{18}F$]FMBS), a newly developed derivative of spiperone, as a potentially more selective radiotracer for the dopamine (DA) $D_2$ receptors. Mice received 1.9-3.7 MBq (1.8-3.6 nmol/kg) of [$^{18}F$]FMBS by tail vein injection. The time course and regional distribution of the tracer in brain were assessed. Blocking studies were carried out by intravenously preinjecting DA $D_2$ receptor blockers (spiperone, butaclamol) as well as drugs with high affinity for DA $D_1$ (SCH 23390), DA transporter (GBR 12909), and serotonin $S_2$ ($5-HT_2$) (ketanserin) sites. After injection of the tracer, the radioactivity in striatum increased steadily over time, resulting in a striatal-to-cerebellar ratio of 4.8 at 120 min postinjection. By contrast, the radioactivity in cerebellum, frontal cortex, and remaining cortex washed out rapidly. Preinjection of unlabeled FMBS (1 mg/kg) and spiperone (1 mg/kg) reduced [$^{18}F$]FMBS striatal-to-cerebellar ratio by 41% and 80%, respectively. (+)-Butaclamol (1 mg/kg) blocked 80% of the striatal [$^{18}F$]FMBS binding, while (-)-butaclamol (1 mg/kg) did not. Preinjection of SCH 23390 (1 mg/kg) and GBR 12909 (5 mg/kg) had no significant effect on [$^{18}F$]FMBS binding. Ketanserin (1 mg/kg), a ligand for the $5-HT_2$ receptors, did not cause significant inhibition either in striatum, in frontal cortex, or the remaining cortex. The results demonstrate that [$^{18}F$]FMBS labels DA $D_2$ receptors selectively in vivo in the mouse brain. It may hold promise as a selective radiotracer for studying DA $D_2$ receptors in vivo by PET.

• ETRI Journal
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• v.29 no.3
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• pp.408-410
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• 2007

A 9-bit 80-MS/s CMOS pipelined folding analog-to-digital converter employing offset-canceled preamplifiers and a subranging scheme is proposed to extend the resolution of a folding architecture. A fully differential dc-decoupled structure achieves high linearity in circuit design. The measured differential nonlinearity and integral nonlinearity of the prototype are ${\pm}0.6$ LSB and ${\pm}1.6$ LSB, respectively.