• Journal of Information Technology Applications and Management
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• v.27 no.6
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• pp.153-170
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• 2020

The Educational Restitution Rate is an important parameter that determines the quality of university education. This paper analyzed data from 148 private universities over the 10 years from 2009 to 2018 using data mining techniques in Korea. A significant causal relationship is detected in the fixed effect model as a result of the panel estimation. And the scale of faculty expansion and fund management, which are the university evaluation indicators, and the size of basic funds, respectively, have a positive effect on the ERR, which is within the confidence interval. In the analysis, the more private universities improve the tuition dependence rate, the more decisively positive affecting ERR. As a result of nonparametric regression estimation, when the faculty expansion ratio is reinforced, the effect of economies of scale is detected in some sections, the improvement of the tuition dependence rate, and the result value is generated through the improvement that results are derived at a certain point in time. We hope that the university based on this study can be a basic Indicators for the diagnosis of basic competencies and policy of student-centered education.

• Structural Engineering and Mechanics
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• v.58 no.4
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• pp.719-729
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• 2016

The main objective of the present paper is to study the effect of the yield criterion on the magnitude of the strain rate and plastic work rate intensity factors in axisymmetric flow of isotropic incompressible rigid perfectly plastic material by means of a problem permitting a closed-form solution. The boundary value problem consisting of the axisymmetric deformation of a plastic tube is solved. The outer surface of the tube contracts. The radius of the inner surface does not change. The material of the tube obeys quite a general yield criterion and its associated flow rule. The maximum friction law is assumed at the inner surface of the tube. Therefore, the velocity field is singular near this surface. In particular, the strain rate and plastic work rate intensity factors are derived from the solution. It is shown that the strain rate intensity factor does not depend on the yield criterion but the plastic work rate intensity factor does.

• ETRI Journal
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• v.16 no.3
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• pp.11-26
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• 1994

In Korea, the price schedule for local telephone combines two-part tariffs and peak-load pricing subject to rate-of-return (RoR) regulation. Although the effect of RoR regulation on two-part tariffs or peak-load pricing has been separately analyzed by many authors in some detail, the behaviour of regulated firm under combined two-part and peak-load pricing has not been studied until now. This paper examines the effect of regulation on the rate structure and welfare under combined two-part and peak-load pricing.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.586-592
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• 2017

This study analyzed the effect of four control factors, RPM, load, EGR rate and cooling water temperature on the exhaust emissions of the small DI diesel engine. The amount of NOx and smoke emissions were measured through experiments for three levels of four control factors according to orthogonal array table, and the effect of four factors on NOx and smoke emissions was analyzed quantitatively. The main results obtained in this study are summarized as follows: 1. RPM, load and EGR rate have a great influence on NOx and smoke emissions, and the effect of cooling water temperature is negligible. 2. As RPM and load increases NOx emission increases and decreases sharply as the EGR rate increases. 3. Smoke emission decreases or increases randomly according to RPM and load, but increases sharply in proportion to the EGR rate. 4. EGR rate has the greatest effect on NOx and smoke emissions by more than 60% of contribution to variance, especially in the case of NOx emission, EGR rate represents a significant result even under the confidence level of 99% on ANOVA.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.966-974
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• 2019

Arthrospira platensis has been reported to contain a variety of substances such as phycocyanin, ${\beta}$-carotene, vitamin E and other carotenoids. In this study, zebrafish were treated with indoor cultivation spirulina ethanol extracts(ICAE) to determine toxicity(coagulation rate, hatching rate, heart rate). We used the DCFH-DA staining method to detect the effect of reactive oxygen species(ROS) generation on lipopolysaccharide(LPS)-induced zebrafish embryos ROS various concentrations(0.01, 0.05, 0.1, 0.5mg/ml) of ICAE. Cell toxicity was measured by WST-1 assay on RAW 264.7 macrophage cell line. Also, measured the inhibitory effect of nitric oxide(NO) and prostaglandin $E_2$ ($PGE_2$) production in RAW264.7 macrophages induced by LPS at various concentrations of ICAE. The results of embryo coagulation rate, hatching rate, heart rate of zebrafish at various(0.01, 0.05, 0.1mg/ml) of ICAE was no toxicity. The ICAE treated group had an inhibitory effect on NO and $PGE_2$ production compared and decreased with concentration. The results of this study ethanol extract of Arthrospira platensis has an anti-inflammatory effect and suggest that is worthy of use cosmetics for skin protection.

• Industry Promotion Research
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• v.1 no.1
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• pp.129-135
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• 2016

This study verified the water saving effect in case of raising water rate depends on water rate awareness. The study results showed that the perceived appropriacy of government aid(p<.001), home water rate(p<.01), water rate pricing system, water rate, water rate diffrences depend on use and area(p<.05) significantly affected the degree of agreement of raising water rate. Also, education, residence, member of household, occipation, monthly household income, monthly water rate significantly affected the degree of agreement of raising water rate, consumer behavior for saving water. This study provided implication for water rate pricing policy by analyzing the water saving effect in case of raising water rate depends on water rate awareness and revealing the determinants of the degree of agreement of raising water rate.

• The Journal of the Korea Contents Association
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• v.13 no.1
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• pp.417-424
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• 2013

The purpose of this study is to find out the effect of macroeconomic variables on the hotel profitability and suggest the reasonable way to handle them. To achieve this purpose, seven macroeconomic variables were used as an independent variable. These were the index of industrial production, West Texas Intermediate, the consumer price index, the unemployment rate, the money supply, the trade balance and the exchange rate. And ROA and ROE of total hotels were used as a dependant variable respectively. As the result of regression, it was found that the index of industrial production and the exchange rate had a significant and positive effect on ROA. And West Texas Intermediate, the consumer price index and the unemployment rate had a significant and negative effect on ROA. Also the consumer price index and the unemployment rate had a significant and negative effect on ROE and the exchange rate had a significant and positive effect on ROE. Through the analysis two key variables were found to be very important ones. These were the unemployment rate and the exchange rate. So the hotel managers need to emphasize on the good price of domestic hotel products and supply the various productions and services to the guests when the exchange rate is increased. But when the unemployment rate is increased, the hotel managers should consider to supply the middle price products with the hight price products.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.3
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• pp.293-301
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• 2014

We present a study of vertical dynamics control of an electrostatically levitated gyro-accelerometer considering the wobbling effect and propose a tilt stabilization method with newly introduced control electrodes. Typically, a rotor in a vacuum rotates at high velocity, which may create a drift rate and lead to displacement instability due to the tilt angle of the rotor. To analyze this, first we set up a vertical dynamic equation and determined simulation results regarding displacement control. After deriving an equation for drift dynamics, we analyzed the drift rate of the rotor and the wobbling effect for displacement control quantitatively. Then, we designed new sub-electrodes for moment control that will decrease the drift amplitude of wobbling dynamics. Finally, a simulation study demonstrated that the vertical displacement control with the wobbling compensation electrodes mitigated the rotor's drift rate, showing the effectiveness of the newly proposed control electrodes.

• Journal of applied mathematics & informatics
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• v.7 no.3
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• pp.861-873
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• 2000

Rate-based flow control plays an important role for efficient traffic management of Available Bit Rate(ABR) services. We deal with the problem of the buffer dimension for rate-based ABR control. In this paper, we analyze the Allowed Cell Rate(ACR) of a source and the queue size in a steady state. First, we investigate the effect of the number of active sources on the behavior of the ACR and the maximum queue size. Reflecting the effect of this real scenes, we determine the optimal buffer size and buffer threshold. Furthermore, our analytic results are compared with the case when the effect of the number of active sources is disregarded.

• Transactions of Materials Processing
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• v.19 no.7
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• pp.393-398
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• 2010

This paper investigates the effect of material properties on the formability of sheet metals based on the Marciniak-Kuczynski model (M-K model). The hardening behavior of the material is modeled as the Hollomon model with the strain rate effect. The yield surfaces are constructed with Hosford79 yield function. The material properties considered in this study include the R-value, the strain hardening exponent, the strain rate hardening exponent, and the crystal structure of the material. The effect of the crystal structure on formability is roughly expressed as the change of the yield surface by varying the value of the exponent in Hosford79 yield function. Results show that the R-value affects neither the magnitude nor the shape of right hand side of forming limit diagrams (FLDs). Higher strain hardening exponent and higher strain rate hardening exponent improve the formability of sheet metals because they stabilize the forming processes.