• Journal of Korean Institute of Industrial Engineers
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• v.28 no.4
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• pp.390-396
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• 2002

We present a meaningful interpretation of the equations for the steady-state queue length distribution of the GI/GI/c/K queue so that the equations are better understood and become more applicable. As a byproduct, we present an exact expression of the mean queue waiting time for the M/GI/c queue.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.65-69
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• 2004

This study was performed with Hartmann type dust explosion apparatus and Godbert-Greenwald furnace apparatus in order to research the effect of temperature and humidity affecting LEL, minimum ignition temperature of Hydroxy Propyl Methyl Cellulose. The experimental determinations in the range between $20^{\circ}C\;and\;60^{\circ}C$ of temperature was not affected $LEL(180g/m^3)$ but LEL showed $200g/m^3\;and\;250g/m^3\;at\;80^{|circ}C\;and\;100^{\circ}C$. As the change of humidity LEL was $180g/m^3\;for\;50\%,\;200g/m^3\;for\;60\%\;and\;250g/m^3\;for\;70\%$ but dust explosion didn't occur over $80\%$. The ignition temperature of HPMC dust clouds was increased as increasing of humidity. So, the minimum ignition temperatures at $50\%,\;60\%,\;70\%\;80\%$ of humidity was $363^{\circ}C,\;375^{\circ}C,\;397^{\circ}C,\;405^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.39-51
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• 1991

The primary production of phytoplankton in oyster farming bays were seasonally measured by $^{14}C$ method in Hansan-Koje Bay and Kamagyang Bay for one year period. In Hansan-Koje Bay, mean daily prima production was $0.52gC/m^2/day\;(0.22{\~}1.02gC/m^2/day)$, and it was relatively high in summer and low in winter. Annual primary production was estimated to be $189gC/m^2/yr.$. Mean chlorophyll a content was $1.70mg/m^3$, and it was relatively high in summer. In Kamagyang Bay, mean daily prima production was $0.91gC/m^2/day(0.11{\~}3.61gC/m^2/day)$. and it was maximum in summer and minimum in fall. Annual primary production was estimated to be $334gC/m^2/yr$. Mean chlorophyll a concentration was $2.34mg/m^3$, and it was maximum in summer and relatively high in winter. Considering the water area of the two osyter farming bays, annual carbon production by phytoplankton were 9,450 ton in Hansan-Koje Bay and 37,000 ton in Kamagyang Bay. In general pattern of primary production in these bays, high production occurs in summer with increasing trend since spring.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.380-384
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• 1988

The coefficients of the hot-air and freeze dried garlic isotherms and the critical water activities of these were estimated to be 0.85-0.94 by the linear regression and 0.58-0.60 by the sensory evaluation and ${\Delta}E$ value. Water adsorption rate(K) of hot-air dried garlic packaged with $48{\mu}m$ low density polyethylene(LDPE) decreased from $0.12g\;H_2O/100g/day\;to\;0.093g\;H_2O$/100g/day with decreasing the package dimension from $0.051m^2\;to\;0.029m^2\;at\;40^{\circ}C$ and 75% RH, and that of freeze dried one decreased from $0.17g\;H_2O/100g/day\;to\;0.12g\;H_2O$/100g/day as the filling weight increased from 50g to 10g in the package of $0.051m^2$. Shelf-life of hot-air dried garlic packaged with $80{\mu}m$ LDPE were 99days at $40^{\circ}C,\;283day\;at\;30^{\circ}C\;and\;455\;days\;at\;15^{\circ}C$ in the 75% RH. The differences of water contents between predicted data with water vapor permeability of the conventional method and experimental data were 0-1.5% in the water content range of around 13-18%, but about 2 in the water content range of around 8-11%.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.522-525
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• 2014

The effects of temperature and inosine monophosphate (IMP) on the germination of artificially inoculated Bacillus cereus spores in ganjang, doenjang, and gochujang sauces were investigated. The pH and salt concentration of the sauces were as follows: ganjang (4.84, 7.45%), doenjang (4.26, 5.07%), and gochujang (3.54, 3.24%), respectively. Treatment at $40^{\circ}C$ or $80^{\circ}C$ resulted in a B. cereus growth of 0.8 log CFU/g in ganjang sauce; this concentration increased to 2.25 log CFU/g and 1.21 log CFU/g, respectively, when 10 mM IMP was added. Compared with that for ganjang sauce, the germination effect was comparatively lower for doenjang sauce by 10 mM IMP+$40^{\circ}C$ treatment (0.46 log CFU/g) and 10 mM IMP+$80^{\circ}C$ treatment (0.85 log CFU/g). However, no germination effect was noted for gochujang sauce by any treatment in this study. Therefore, the results suggested that pH is an important factor affecting spore germination in sauces.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.320-326
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• 2018

In this study, Graphite/Silicon/Carbon (G/Si/C) composites were synthesized to improve the electrochemical properties of Graphite as an anode material of lithium ion battery. The prepared G/Si/C composites were analyzed by XRD, TGA and SEM. Also the electrochemical performances of G/Si/C composites as the anode were performed by constant current charge/discharge, rate performance, cyclic voltammetry and impedance tests in the electrolyte of $LiPF_6$ dissolved inorganic solvents (EC:DMC:EMC=1:1:1 vol%). Lithium ion battery using G/Si/C electrode showed better characteristics than graphite electrode. It was confirmed that as the silicon content increased, the capacity increased but the capacity retention ratio decreased. Also, it was shown that both the capacity and the rate performances were improved when using the Silicon (${\leq}25{\mu}m$). It is found that in the case of 10 wt% of Silicon (${\leq}25{\mu}m$), G/Si/C composites have the initial discharge capacity of 495 mAh/g, the capacity retention ratio of 89% and the retention rate capability of 80% in 2 C/0.1 C.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.415-418
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• 1999

The characteristics of VRLA (valve regulated Iead-acid) battery with the tubular positive plate and gel type electrolyte were examined as a function of active material filling density. The filling density of positive plate was 3.2 g/mL, 3.4 g/mL, and 3.6 g/mL, respectively. These VRLA batteries were cycled with 100% DOD (depth of discharge) at the $C_5/5$ rate, followed by IU-type recharge with $I_{max}=0.2C_{10}/10$ and a final voltage V=2.40 V/cell. The test was performed in a thermostatic room at $25{\pm}1^{\circ}C$. The result indicated that the initial capacity was independent of active material filling density, i.e., the highest initial capacity was 3.4 g/mL of filling density and the lowest was 3.6 g/mL. On aspect of the cycle-life performance of the VRLA battery, the filling density of 3.6 g/mL was similar to that of 3.4 g/mL in the positive plate, and both were higher than that of 3.2 g/mL. Water-loss and degradation of the VRLA battery were decreased according to an increase of the filling density in the positive plate. The optimum filling density of the active material was 3.4~3.6 g/mL.

• The Korean Journal of Ecology
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• v.28 no.6
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• pp.347-351
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• 2005

The amounts of organic carbon and several nutrients in litterfall on the forest floor of Quercus mongolica forest were assessed for two years from 1998 through 2000 in Mt. Songnisan National Park in Korea. The amounts of organic carbon (C) in litterfall were the highest in autumn with the values of $150.4g/m^2$ (62.6%) in 1998 and $219.2g/m^2$ (61.0%) in 1999. In winter, organic C was the lowest with the values of $16.3g/m^2$ (6.8%) in 1998 and $12.5g/m^2$ (6.7%) in 1999. It was estimated that the organic C added to forest floor via litterfall was 240.1 $g{\cdot}m^{-2}yr^{-1}$ and 186.6 $g{\cdot}m^{-2}yr^{-1}$ 1998 and 1999, respectively. The amounts of nitrogen (N) in litterfall were the highest in autumn with the values of 5.9 $g/m^2$ (58.0%) in 1998 and 5.2 $g/m^2$ (62.3%) in 1999. The amount of phosphorus (P) in litterfall showed its peak in autumn with 0.19 $g/m^2$ (52.9%) in 1998 and 0.11 $g/m^2$ (52.6%) in 1999. The amount of P returned to forest floor via litterfall was 0.35 $g{\cdot}m^{-2}yr^{-1}$ in 1998 and 0.22 $g{\cdot}m^{-2}yr^{-1}$ in 1999. The amount of potassium (K) in litterfall showed its peak in autumn with 0.57 $g/m^{2}$ (53.8%) in 1998 and 0.42 $g/m^2$ (55.3%) in 1999. The amounts of K returned to forest floor via litterfall was 1.11 $g{\cdot}m^{-2}yr^{-1}$ in 1998 and 0.81 $g{\cdot}m^{-2}yr^{-1}$ in 1999.

• Journal of fish pathology
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• v.35 no.2
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• pp.241-246
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• 2022

White spot syndrome virus (WSSV) is a prevalent and virulent pathogen affecting cultured whiteleg shrimp (Litopenaeus vannamei) in Korea. In this study, seven monoclonal antibodies (mAbs) (10A12, 16C3, 17G4, 21G5, 22C4, 23B6 and 24G6) were produced by using purified WSSV. The reactivity of these mAbs was analysed by Western blot (WB), indirect immunofluorescence (IIF), and lateral flow immunochromatographic assay (LFIA). WB analysis demonstrated that three mAbs (17G4, 22C4, and 23B6) reacted specifically to VP28 with an approximate molecular weight of 24 kDa, mAb 16C3 reacted with approximately 17 kDa. IIF analysis demonstrated specific fluorescence signals on gill tissues of WSSV-infected shrimp, with five mAbs (10A12, 16C3, 22C4, 23B6, and 24G6), pleopods from WSSV-infected shrimp were used for LFIA, where, two mAbs (21G5 and 22C4) exhibited positive reaction. In conclusion, it can be inferred that the mAbs usage and specificity depends on the nature of assay used for diagnosis.

• Journal of the Korean Mathematical Society
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• v.36 no.1
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• pp.97-107
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• 1999

Given a C-dynamical system (A, G, $\alpha$) with a locally compact group G, two kinds of C-algebras are made from it, called the full C-crossed product and the reduced C-crossed product. In this paper, we extend the theory of the classical C-crossed product to the C-dynamical system (A, G, $\alpha$) with a left-cancellative semigroup M with unit. We construct a new C-algebra A $\alpha$rM, the reduced crossed product of A by the semigroup M under the action $\alpha$ and investigate some properties of A $\alpha$rM.