• Journal of Korea Water Resources Association
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• v.42 no.8
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• pp.659-671
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• 2009

Fuzzy c-means clustering technique is applied to improve the accuracy of G/R ratio used for rainfall estimation by radar reflectivity. G/R ratio is computed by the ground rainfall records at AWS(Automatic Weather System) sites to the radar estimated rainfall from the reflectivity of Kwangduck Mt. radar station with 100km effective range. G/R ratio is calculated by two methods: the first one uses a single G/R ratio for the entire effective range and the other two different G/R ratio for two regions that is formed by clustering analysis, and absolute relative error and root mean squared error are employed for evaluating the accuracy of radar rainfall estimation from two G/R ratios. As a result, the radar rainfall estimated by two different G/R ratio from clustering analysis is more accurate than that by a single G/R ratio for the entire range.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.925-931
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• 2018

The characteristics of $PM_{10}$, $PM_{2.5}$ and Ratio($PM_{2.5}/PM_{10}$) of 11 urban air monitoring stations in Gyeongnam were analyzed for the last 3 years('15~'17). The average of the all stations was $PM_{10}\;45{\mu}g/m^3$, $PM_{2.5}\;24{\mu}g/m^3$ and Ratio 0.54, and annual reduction rates were $PM_{10}-2.9%$, $PM_{2.5}-2.7%$ and Ratio -1.2%, respectively. The seasonal characteristics of $PM_{10}$ were spring $54{\mu}g/m^3$ > winter $48{\mu}g/m^3$ > summer/autumn $40{\mu}g/m^3$, $PM_{2.5}$ were spring/winter $26{\mu}g/m^3$ > summer 23 > autumn $22{\mu}g/m^3$ and Ratio were summer 0.56 > winter 0.55 > autumn 0.54 > spring 0.51, respectively. The hourly characteristics of $PM_{10}$ were $11{\mu}g/m^3$ higher than 09:00~12:00 at 03:00~06:00, $PM_{2.5}$ were $6{\mu}g/m^3$ higher than 09:00~12:00 at 17:00~18:00 and Ratio were 0.07 higher than 04:00~06:00 at 19:00. By site, the highest concentration of $PM_{10}$ was YJ site $53{\mu}g/m^3$ and $PM_{2.5}$ was HW site $28{\mu}g/m^3$. And Ratio at HD site showed the largest reduction from '15 0.62 to '17 0.52.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.162-175
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• 2015

The purpose of this thesis was to develop pumpkin soup with different ratios of ingredients, using high-nutrient sweet pumpkins. P10G0 without sweet pumpkin and glutinous rice powder showed the highest moisture content, whereas, P5G0 whit Cheongdung pumpkin and sweet pumpkin at the same ratio whitout glutinous rice powder showed the lowest moisture content. For chromaticity lightness of control pumpkin soup scored the lowest. Lightness of P10G0 without sweet pumpkin and glutinous rice powder also scored the lowest. For redness, the P5 group with Cheongdung pumpkin and sweet pumpkin at the same ratio scored the highest while the P10 group without sweet pumpkin scored the lowest. As for yellowness, increased ratio of glutinous rice powder in pumpkin soup scored resulted in reduced yellowness in all groups P5 (p<0.01), P7 and P10 (p<0.001) A higher ratio of Cheongdung pumpkin was thus generally associated whit reduced yellowness (p<0.001). For the spread-ability, higher ratio of sweet pumpkin to Cheongdung pumpkin resulted in significant reduction of spread-ability. However, groups with 12% glutinous rice powder showed no significant differences. Spread-ability of the P5 and P10 groups significant increased and thereafter decreased according to the addition ratio of glutinous rice powder, viscosity of the G0 and G4 groups decreased according to the addition ratio of Cheongdung pumpkin, whereas they first decreased and then increased in the G8 and G12 groups. All groups showed increased viscosity whit more glutinous rice powder. For the sensory evaluation, P5G8 was mostly preferred in all aspects. P7G4 was superior in all aspects except for flavor. P10G4 scored the highest in all aspects except viscosity. For acceptance test, except for the control group, P7G4 whit added of 70% Cheongdung pumpkin, 30% sweet pumpkin and 4% glutinous rice powder was the most preferred in all aspects except color (gloss, viscosity, flavor, taste and overall quality).

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.17-28
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• 2011

This study applied the Kalman Filter for real-time forecasting the G/R (ground rain gauge rainfall/radar rainfall) ratio to correct the mean field bias of the very-short-range-forecast (VSRF) rainfall. The MAPLE-forecasted rainfall was used as the VSRF rainfall, also the methodology for deciding the G/R ratio was improved by evaluating the change of G/R ratio characteristics depending on the threshold and accumulation time. This analysis was done for the inland, mountain, and coastal regions, separately, for their comparison. As the results, more stable G/R ratio could be estimated by applying the threshold and accumulation time, whose forecasting accuracy could also be secured. The accuracy of the corrected rainfall forecasting by the forecasted G/R ratio was the best in the inland region but the worst in the coastal region.

• Geomechanics and Engineering
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• v.24 no.1
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• pp.57-65
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• 2021

The effects of initial soil fabric and aspect ratio (AR) on the small-strain stiffness (G0) of granular soils are studied by employing discrete element method (DEM) numerical analysis. Elongated clumps composed of subspheres were adopted, and the G0 values were obtained by DEM simulations of drained triaxial tests under different densities and initial confining pressure (p0). The DEM simulations indicate that the initial soil fabric has an insignificant effect on G0. The effect of the AR on G0 is related to the initial density. Namely, for dense specimens, G0 first increases with increasing AR, reaching a plateau value when the AR ≥ 1.5. However, for loose specimens, G0 gradually increases as the AR increases. Microscopic examination reveals that G0 uniquely depends on the coordination number of the particles (CN-particle) rather than the subspheres (CN-sphere) at the particulate level for the effects of initial soil fabric and AR. Finally, Poisson's ratio ν0 is also determined by CN-particle. In addition, based on data in literature and this study, ν0 can be fitted as ν0 = 5.920(G0/(p0)1/3)-0.99, which can be used to predict ν0 of granular soils based on the measured G0.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.825-831
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• 2012

The retrofitting of a thickening unit process is widely considered in municipal wastewater treatment plants in Korea to enhance the anaerobic digestion efficiency. The authors examined the effect of feed concentration (2-34.1 g VS/L) and feed to microorganism (F/M) ratio (0.50-1.35 g VS/g VS) on anaerobic batch digestion of sewage sludge. Methane yield over 90 mL $CH_4/g$ $VS_{feed}$ was found at a feed concentration in the range of 12-26 g VS/L and a F/M ratio below 0.6 g VS/g VS. A high F/M ratio decreased methane yield and rate with oragnic acid accumulation. As sudden increase of sewage sludge concentration prior to anaerobic digestion would jeopardize the digester performance due to the rasied F/M ratio, gradual increase of the sludge feed concentration or an additional biomass retention in the digester is recommended.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.810-816
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• 1996

This study was conducted to measure the hydration characteristics at $20^{\circ}C$ and investigated the effect of water to rice ratio(v/w) on the texture properties of cooked rice of ten different varieties based on maturity. Water absorptions during soaking were completed between 30min and 35min at $20^{\circ}C$. The ranges of equilibrium moisture content were between 0.3247g $H_2O/g$ dry matter and 0.3577g H201g dry matter. During the cooking process, the water content of cooked rice increased 6~7% with increased the ratio of water to rice from 1.4 to 1.6(v/w). The hardness(H) of cooked rice decreased, while the stickiness(-H) and -H/H ratio increased with increased ratio of water to rice.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.69-74
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• 2002

The following results are achieved from a mortar flow test depending on stainless steel slag fineness, replacement ratio, and a research on material age compressive strength, strength activity index. 1. Flow is proportional to the stainless steel slag fineness within the limits of 4000~8000$\textrm{cm}^2$/g, but in the case of fineness 20000$\textrm{cm}^2$/g flow decreases at all conditions except the case of replacement ratio 10%. 2. As stainless steel slag replacement ratio increases, Mortar of flow somewhat decreases. 3. As stainless steel slag blends, compressive strength decreases, but in proportion to the increase of age, compressive strength increases. 4. As stainless steel slag replacement ratio, compressive strength decreases. 5. In the case of stainless steel slag fineness 6000$\textrm{cm}^2$/g and 20.000$\textrm{cm}^2$/g, compressive strength of revelation ratio has the maximum value when it's replacement ratio is 10%.

• KSBB Journal
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• v.9 no.4
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• pp.365-371
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• 1994

The effects of ratios of initial concentration of carbon source to the initial concentration of nitrogen source in the fermentation media on both the yields of PHB fermentation variables and the accumulation of poly-${\beta}$-hydroxybutyric acid(PHB) were investigated. The fermentation media were composed of the combination of varing glucose concentrations, 10, 20, 25, 30, 40, $50g/\ell$ and the NH4Cl concentrations 0.33, 0.4, 0.5, 1.5, 3, $5g/\ell$. The yield of biomass on glucos, Yx/s, decreased very slowly according to the increase of the ratio of C to N. And the yield became constant at 0.35(g biomass/g glucose) with the ratio higher than 70. The yield of residual biomass, Yx/s, also decreased with the ratio of C to N and finally showed a constant value of 0.065(g residual biomass/g glucose) when the ratio was higher than 65. In accordance with the augmentation of the ratio, the yield of PHB, YPHB/S, however, increased and showed the maximum value of 0.35 (g PHB/g glucose) between 40 and 60 of the ratio. The maximum yield of PHB to the change of biomass, YPHB/S, was 0.87(g PHB/g biomass), and the yie1d YPHB/RX, was 4.2(g PHB/g residual biomass). The maximum accumulation percent of PHB to the final biomass was 81% when the ratio was higher than 67.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1282-1289
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• 2001

One feeding trial and two metabolic trials were conducted to investigate the effects of lysine to protein ratio in practical swine diets on growth performance and efficiency of nitrogen retention and utilization in different growing phases. In Trial one (the feeding trial), 90 mixed sex pigs weighing $9.1{\pm}1.4kg$ (Duroc ${\times}$ Landrance ${\times}$ Beijing Black) were used to study the effects of concentrations of 5.2, 5.3, 5.8, 6.4 and 7.2 g lysine/100 g CP in diets containing 1.2% lysine on growth performance and serum urea nitrogen. The results showed that feed conversion efficiency and economic efficiency were best for pigs fed the diet containing the lysine concentration of 5.8 g /100 g crude protein. Serum urea nitrogen concentration decreased linearly (p=0.0009) and serum free lysine content increased linearly (p=0.0017) as the lysine to protein ratio in diets increased from 5.2 to 7.2 g/100 g. In Trials two and three (the metabolic trials), five growing barrows (Duroc ${\times}$ Landrance ${\times}$ Beijing black), with initial body weights of approximately $26{\pm}2.4kg$ and $56.3{\pm}3.5kg$, respectively, were allotted to five dietary treatments according to a $5{\times}5$ Latin square design. Trial two contained 5.2, 5.7, 6.1, 6.7 and 6.8 g lysine/100 g CP treatments. Trial three contained 4.6, 5.0, 5.6, 6.1 and 6.6 g lysine/100 g CP treatments. The results showed that nitrogen retention in growing pigs decreased linearly (p=0.0011 in Trial two; p=0.0099 in Trial three) as the lysine to protein ratio in diets increased. The ratio of lysine to protein in diets resulting in maximum nitrogen retention was 5.2 g/100 g and 5.0 g/100 g in Trial two and Trial three, respectively. In Trial two, apparent biological value and gross nitrogen efficiency increased linearly (p=0.0135 and p=0.0192, respectively) as the lysine to protein ratio increased from 5.2 to 6.8 g lysine/100 g CP. In summary, we concluded that the optimal Lysine to Protein Ratios for 8-20 kg and 20-80 kg pigs were 5.8 g/100 g and 5.0 to 5.2 g/100 g, respectively.