• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.212-217
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• 1989

The shrinking and overall drying rate equations which can accomodate experimental date and the rate of initial drying ratio were investigated. The results obtained from hot air drying experiments of radish and sweet potatoes were as follow. The drying rate constant and the order were affected by the thickness of sample and temperature. The empirical drying rate and shrinking equations at constant drying conditions (d=4mm, $Ta=50^{\circ}C$, RH=10%, U=0.8m/s) for radish and sweet potatoes were found to $dx/dt=0.112{\times}10^{-2}\;A(1-x)^{0.43}$, A=Ao(-0.480x+1) and rates of initial drying ratio were expressed of sample thickness, relative humidity and air velocity; for radish $dx/dt=0.0648(RH)^{-0.31}\;(d)^{-0.75}\;(U)^{0.39}$ and for sweet potatoes $dx/dt=0.0547(RH)^{-0.28}\;(d)^{-0.63}\;(U)^{0.37}$

• International Journal of Advanced Culture Technology
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• v.7 no.1
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• pp.84-88
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• 2019

This paper examines whether the exchange rate respond differently to monetary policy shocks in Korea using regression model. We find an asymmetric response of the monetary policy shocks to the monetary policy shocks in the context of Korea. Over the whole period sample, we do not find the effect of an actual interest rate on exchange rate. But we find that the estimated coefficient on the expected and unexpected change in the policy rate are negative and statistically significant. In the period of monetary policy easing, the estimated coefficient on the expected and unexpected change in the policy rate are negative but not statistically significant. In contrast, the period of monetary policy tightening, the estimated coefficient on the expected and unexpected change in the policy rate are negative and statistically significant.

• Analytical Science and Technology
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• v.27 no.1
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• pp.34-40
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• 2014

SPLITT fractionation (SF) allows continuous (and thus a preparative scale) separation of micronsized particles into two size fractions ('fraction-a' and 'fraction-b'). SF is usually carried out in a thin rectangular channel with two inlets and two outlets, which is equipped with flow stream splitters at the inlet and the outlet of the channel, respectively. A new large scale splitter-less gravitational SF (GSF) system had been assembled, which was designed to eliminate the flow stream splitters and thus is operated by the full feed depletion (FFD) mode (FFD-GSF). In the FFD mode, there is only one inlet through which the sample is fed. There is no carrier liquid fed into the channel, and thus prevents the sample dilution. The effects of the sample-feeding flow rate, the channel thickness on the fractionation efficiency (FE, number % of particles that have the size predicted by theory) of FFD-GSF was investigated using industrial polyurethane (PU) latex beads. The carrier liquid was water containing 0.1% FL-70 (particle dispersing agent) and 0.02% sodium azide (used as bactericide). The sample loading rate was varied from about 4 to 7 L/hr with the sample concentration fixed at 0.01%. The GSF channel thickness was varied from 900 to $1300{\mu}m$. Particles exiting the GSF channel were collected and monitored by optical microscopy (OM). Sample recovery was monitored by collecting the fractionated particles on a $0.45{\mu}m$ membrane filter. It was found that FE of fraction-a was increased as the channel thickness increases, and FE of fraction-b was increased as the flow rate was increased. In all cases, the sample recovery has higher than 95%. It seems the new splitter-less FFD GSF system could become a useful tool for large scale separations of various types of micron-sized particles.

• The Korean Journal of Applied Statistics
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• v.26 no.4
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• pp.595-610
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• 2013

Testing of order-restricted alternative hypothesis in $2{\times}k$ contingency tables can be applied to various fields of medicine, sociology, and business administration. Most testing methods have been developed based on a large sample theory. In the case of a small sample size or unbalanced sample size, the Type I error rate of the testing method (based on a large sample theory) is very different from the target point of 5%. In this paper, the exact testing method is introduced in regards to the testing of an order-restricted alternative hypothesis in categorical data (particularly if a small sample size or extreme unbalanced data). Power and exact p-value are calculated, respectively.

• Communications for Statistical Applications and Methods
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• v.22 no.5
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• pp.519-530
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• 2015

The geometric chart has proven more effective than Shewhart p or np charts to monitor the proportion nonconforming in high-quality processes. Implementing a geometric chart commonly requires the assumption that the in-control proportion nonconforming is known or accurately estimated. However, accurate parameter estimation is very difficult and may require a larger sample size than that available in practice in high-quality process where the proportion of nonconforming items is very small. Thus, the error in the parameter estimation increases and may lead to deterioration in the performance of the control chart if a sample size is inadequate. We suggest adjusting the control limits in order to improve the performance when a sample size is insufficient to estimate the parameter. We propose a linear function for the adjustment constant, which is a function of the sample size, the number of nonconforming items in a sample, and the false alarm rate. We also compare the performance of the geometric charts without and with adjustment using the expected value of the average run length (ARL) and the standard deviation of the ARL (SDARL).

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.116-117
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• 2008

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.545-546
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• 2018

• Korean journal of food and cookery science
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• v.32 no.2
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• pp.178-187
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• 2016

Purpose: This study investigated the quality characteristics of Jeungpyun prepared with brown rice and sea tangle powder. Methods: The pH, volume, and spreadability of the dough and moisture content, color, texture and sensory evaluation of the Jeungpyun were performed. Results: The results showed that the pH of the dough decreased in all sample groups with the lapse of fermentation time, and ultimately revealed a pH ranging from 4.55-4.65. The spreadability of the dough significantly decreased as the substitute amount of the brown rice flour increased; the sample group with 1% sea tangle powder showed a significantly larger spreadability than the sample group with 2% sea tangle powder (p<0.05). The moisture content in the Jeungpyun showed a significantly lower result as the substitute amount of brown rice flour increased (p<0.05). Lightness (L) was reduced as the substitute amount of brown rice flour increased, and redness (a) and yellowness (b) also appeared to increase. As a result of measuring the texture, the 50% sample group with a high substitute rate of brown rice flour was observed to have high characteristics of hardness, gumminess and chewiness, and was low in cohesiveness. The result of the acceptance test showed that the sample group that substituted 25% brown rice flour and added 1% sea tangle powder was evaluated to have a significantly higher acceptance than the sample group that added 2% sea tangle powder in terms of color, texture and overall acceptance. Conclusion: The result of the acceptance test showed that the sample group that substituted 25% of brown rice flour and added 1% of sea tangle powder showed higher tendency in all acceptance attributes than the sample group that did not substitute the brown rice flour to show the possibility of developing the Jeungpyun with brown rice.

• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.353-365
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• 2008

The sample size in a clinical trial is determined by the hypothesis, the variance of observations, the effect size, the power and the significance level. Dropouts in clinical trials are inevitable, so we need to consider dropouts on the determination of sample size. It is common that some proportion corresponding to the expected dropout rate would be added to the sample size calculated from a mathematical equation. This paper proposes new equations for calculating sample size dealing with dropouts. Since we observe data longitudinally in most clinical trials, we can use a last observation to impute for missing one in the intention to treat (ITT) trials, and this technique is called last observation carried forward(LOCF). But LOCF might make deviations on the assumed variance and effect size, so that we could not guarantee the power of test with the sample size obtained from the existing equation. This study suggests the formulas for sample size involving information about dropouts and shows the properties of the proposed method in testing equality of means.

• Journal of the Korean Society of Food Culture
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• v.36 no.2
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• pp.218-225
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• 2021

The quality characteristics of sugar-reduced green tea cookies were tested, and there was no significant differences in density, spreadability, loss rate, and pH in all experimental groups (p<0.05). The sugar content of the sample with 100% sugar replaced was 0.96°Brix, which was significantly higher than the 0.80 °Brix of the control (p<0.05). The sample with 75% sugar substituted was 0.76°Brix, which was similar to that of the control (p>0.05). The calories per 100 g of cookies were reduced from 482 to 433 kcal in the sample groups, where the sugar content was reduced from 0 to 100%. Carbohydrates also decreased with decreasing sugar content. The protein was 5g in the sugar sample group reduced by 0-25%, and 6 g in the sugar sample group reduced by more than 50%. Dietary fiber was three times higher in the sugar sample group reduced by 75% than the control, and four times higher in the sugar sample group reduced by 100% than the control. No significant differences in the sweet sensory intensities were observed between the control and the 75% reduced sugar sample group (p>0.05). The brightness, savory, sweet, and aftertastes were similar in all experimental groups (p>0.05). Overall, high value-added green tea cookies with a more than 75% reduction in sugar were successfully developed with added functions of immunity, anti-cancer, antioxidant functions, preventing constipation and obesity, without deteriorating the sensory and physicochemical qualities tested.