• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.198-203
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• 2012

Salting-out technique was adopted to crystallize dye crystals from dye solution. In this research solubility of dye solution and crystallization kinetics of Reactive dye (RB-8, RB-49, RR-218) was investigated. The empirical expressions of salting-out crystallization kinetics for Reactive dye (RB-8, RB-49, RR-218) in continuous MSMPR crystallizer was RB-8 in crystal growth kinetics $G=7.1{\times}10^{-4}{\Delta}C^{0.67}$ and nucleation kinetics $B^0=3.1{\times}10^{15}{\Delta}C[1.2{\times}10^{-8}+{\Delta}C^{0.7}M_T{^2}]$, RB-49 in crystal growth kinetics $G=5.2{\times}10^{-4}{\Delta}C^{0.3441}$ and nucleation kinetics $B^0=7.2{\times}10^{15}{\Delta}C[3.3{\times}10^{-8}+({\Delta}C)^{0.7}M_T{^2}]$, RR-218 in crystal growth kinetics $G=4.4{\times}10^{-4}{\Delta}C^{0.2361}$ and nucleation kinetics $B^0=6.3{\times}10^{15}{\Delta}C[7.9{\times}10^{-8}+({\Delta}C)^{0.7}M_T{^2}]$. Also, comparison of calculated crystal size distribution applying to characteristic curve method with experimental crystal size showed good agreement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6269-6273
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• 2015

Performance of the Alamouti algorithm based M-ary $2{\times}N$ OSTBC(Orthogonal Space Time Block Coded) MIMO(Multi Input Multi Output) system has been simulated varying two main parameters - the number of constellation(M), and the number of receiving antennas(N). Computer simulation has also been carried out using Matlab software for performance comparison between $2{\times}N$ MIMO and MRC(Maximal Ratio Combining) diversity antenna system to evaluate the degree of enhancement achieved through the use of Alamouti $2{\times}N$ MIMO. Under 10 dB EbNo QPSK scenario, $2{\times}1$ MIMO brought 4.2 dB BER improvement over single antenna system and $2{\times}2$ MIMO resulted in 7.4 dB BER improvement over $1{\times}2$ MRC.

• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.5-10
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• 1998

The geometric structure of dimer atoms on clean Si(001) surface was studied using CAICISS. We confirmed that dimer atoms were certainly buckled, and also found that asymmetry (2$\times$1) and c(4$\times$2) were coexisted. The intradimer bond length and the buckling angle of a dimer measured by CAICISS system were 2.3$\pm$0.1 $\AA$ and 18$\pm$$1^{\circ}$, respectively.

• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.512-520
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• 2001

Kimchi is one of the traditional Korean food and a very popular side dish in Korea. To obtain funda mental data on how to prevent over ripening in kimchi after acidity of 0.4% was reached during the lactate fermentation, the physicochemical characteristics such as pH. acidity. organic acids, enzyme activity were measured and the time dependent ecology of microorganism were observed. In the initial stages of fermentation, the pH of kimchi was markedly changed and slowly decreased in 0.5% acidity The acidity was slowly increased and markedly increased in pH 4 by growth of microorganism. HPLC analysis showed oxalic acid, lactic acid, acetic acid, malic acid and succinic acid and this results reconfirmed by GC-MSD. Lactic acid was changed a lot during fermentation period as the time of storage went on, where as malic was decreased. Kimchi A, having acidity of 0.75%, showed the highest acidic Protease and lipase activity. Also, the amylase activity was high in kimchi C, having 0.95% acidity. The total viable bacteria showed 8.1$\times$10$^{5}$ , 4.7$\times$10$^4$, 1.2$\times$10$^3$, 3.2$\times$10$^4$, 4.9$\times$10$^{5}$ cfu/ml in the kimchi A, B, C, D and E, respectively. The numbers of lactic acid bacteria counted 1.0$\times$10$^{5}$ , 1.3$\times$10s, 1.2$\times$10$^3$, 2.3$\times$ 10$^3$, 2.1$\times$10$^4$c1u/m1 in the kimchi A, B, C, D and E, respectively. The numbers of acetobactor were counted 1.8$\times$10$^{5}$ , 9.3$\times$10$^4$, 7.0$\times$10$^1$, 4.5$\times$10$^4$, 5.3$\times$10$^3$cfu/m1 in the kimchi A, B, C, D and E, respectively.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.51-57
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• 2007

This study examined the possibility on the dietary value and cryopreservation of the marine microalga, Isochrysis galbana. Four cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), glycerol (Gly) and 1.2-propanedial (PD) were tested at the concentrations of 1.0, 1.5, 2.0, 2.5 and 3.0 M respectively. The highest survival rates were obtained with 1.5 and 2.0 M of four cryoprotectants yielding a survival rate of 80%. Cell concentration of $30\;{\times}\;10^4\;cell/ml$ at the initial point of the experiment was increased to $365\;{\times}\;10^4\;cell/ml$ in 1.5 M of dimethyl sulfoxide, $298\;{\times}\;10^4\;cell/ml$ in 1.5 M of ethylene glycol, $512\;{\times}\;10^4\;cell/ml$ in 1.5 M of glycerol, and $385\;{\times}\;10^4\;cell/ml$ in 1.5 M of 1.2-propanedial after five days, respectively. In dietary value experiment, survival rate and growth were not significantly different.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.1-8
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• 2006

An experimental study was carried out in order to investigate the influence of Reynolds number on the near-wake of an oscillating airfoil. An NACA 0012 airfoil was sinusoidally pitched at the quarter chord point, and is oscillated over a range of instantaneous angles of attack of $\pm$6$^{\circ}$. An X-type hot-wire probe was employed to measure the near-wake of an oscillating airfoil, and the smoke-wire visualization technique was used to examine the flow properties of the boundary layer. The free-stream velocities were 1.98, 2.83 and 4.03 m/s and the corresponding chord Reynolds numbers were 2.3${\times}10^4$, 3.3$\times$104 and 4.8${\times}10^4$, respectively. The frequency of airfoil oscillation was adjusted to fix a reduced frequency of K=0.1. The results show that the properties of the boundary layer and the near-wake can dramatically be distinguished in the range of Reynolds numbers between 2.3${\times}10^4$ and 3.3${\times}10^4$, on the other hand, it is similar in the cases of Re=3.3$\times$104 and 4.8$\times$104. This is caused by that the unsteady separation point is dramatically delayed in case of Re= 2.3${\times}10^4$.

• Korean Journal of Optics and Photonics
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• v.10 no.1
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• pp.73-79
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• 1999

Semiconductor optical switch modules of 1$\times$2, 1$\times$4, and 4$\times$4 types for 1550 nm optical communication systems were fabricated by using laser welding technique, embodying in 30-pin butterfly package. For better coupling efficiency between switch chip and optical fiber, tapered fibers of 10~15mm lens radii were used, which provided up to 60% optical coupling efficiency. With the help of new laser hammering process, we could recover the lost optical power almost completely up to average 82% of initially obtained power. The fabricated optical switch modules showed good thermal stability of less than 5% degradation even after 200 times thermal cycling test. The 2.5 Gbps optical transmission characteristics of the 4$\times$4 switch module showed low sensitivities of less than -30dB for all possible switching paths. The transmission penalties of 1$\times$2 switch module at $10^{-10}$ BER were 0.6dB and 0.7dB for 50Xm and 90 Km optical fibers, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.153-160
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• 2008

To estimate microbial contaminant loading discharged from diffuse sources, rainfall runoff of six rainfall events were monitored at three study watersheds of forestry and agricultural land use. Monitored indicator microorganism constituents were total coliform (TC), fecal coliform (FC), Escherichia coli (EC), and fecal streptococcus (FS). Soil loss during elevated flow rate caused higher suspended solid concentrations. Indicator microorganism concentrations were closely related with flow rate. TC event mean concentration (EMC) from unpolluted forestry was $5.3{\times}10^3CFU/100ml$, FC EMC was $1.4{\times}10^3CFU/100ml$, EC EMC was $1.1{\times}10^3CFU/100ml$, and FS EMC was $2.9{\times}10^2CFU/100ml$. From a watershed with agricultural-forestry land use, TC EMC was $1.7{\times}10^5CFU/100ml$, FC EMC was $8.5{\times}10^4CFU/100ml$, EC EMC was $8.9{\times}10^4CFU/100ml$, and FS EMC was $3.4{\times}10^4CFU/100ml$. Mixed land use of agricultural-forestry with bigger area, TC EMC was $1.9{\times}10^5CFU/100ml$, FC EMC was $9.6{\times}10^4CFU/100ml$, EC EMC was $7.0{\times}10^4CFU/100ml$, and FS EMC was $5.1{\times}10^4CFU/100ml$.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.39-42
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• 1990

The properties of amylose of cow pea starch were investigated. Amylose content of cow pea was 25.1 % and iodine binding capacity was 20.2 %. The ${\beta}-amylolysis$ limit of the amylose was 82.3%. The limiting viscosity number of the amylose fraction was 204 ml/g and the corresponding average degree of polymerization was 1,510 glucose units. The percent distribution of molecular weight of the amylose by gel chromatography was $1{\times}10^4$(0.7 %), $1{\times}10^4{\sim}4{\times}10^4$(4.1 %), $4{\times}10^4{\sim}5{\times}10^5$(44.6 %), $5{\times}10^5{\sim}4{\times}10^7$(49.6 % ).

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.295-297
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• 2010

H.264/AVC 무손실 인트라 압축을 위하여 사용되는 픽셀 예측 방법은 Sample by Sample DPCM (SbS DPCM) 으로서 이 방법에서는 각각의 픽셀을 주변 픽셀로부터 예측하고 그 오차를 전송한다. 본 논문에서는 $4{\times}4$ 블록에 대한 Multiple Partition 예측과 SbS DPCM을 이용하여 H.264/AVC 의 무손실 인트라 압축 효율을 증가시키는 방법을 제안한다. 제안하는 방법은 각 $4{\times}4$ 블록을 $4{\times}4$, $4{\times}2$, $2{\times}4$, $2{\times}2$, $1{\times}1$ 크기의 sub-partition 을 가지는 다양한 partition 으로 예측한다. 이 때 각 sub-partition 들은 SbS DPCM을 이용하여 예측되고 이 때 사용하는 예측 방향의 개수는 예측 방향 정보량을 고려하여 sub-partition 크기에 따라 조절한다. 실험 결과에 의하면 제안하는 방법은 기존 H.264/AVC에 비하여 최대 17.02 %p, 평균 13.29 %p 의 압축율 개선을 보여주며 SbS DPCM만 사용하는 방법에 비하여 최대 4.74 %p, 평균 3.62 %p 정도의 압축율 개선을 보여준다.