• English Language & Literature Teaching
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• v.9 no.2
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• pp.1-16
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• 2003

This paper describes a video exchange project between English classes in South Korea and in Japan. Korean and Japanese students worked in groups to make short videos in English which were then exchanged. After viewing their counterparts' videos, students e-mailed feedback to each other. This project was the third video exchange project between Korean and Japanese university students since 2001. However, it was the first time to try it with three universities together. Students from the different universities tried to compete with each other. It provided a better chance for students to improve their English. Most students expressed the importance of the video exchange project in developing their English proficiency and enabling them to use English in an international context. Many students agreed that the project was an educational, enjoyable and worthwhile experience.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.843-847
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• 2012

The nucleophilic substitution reactions of dibutyl chlorothiophosphate (4S) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $55.0^{\circ}C$. The obtained deuterium kinetic isotope effects (DKIEs;$k_H/k_D$) are primary normal ($k_H/k_D$ = 1.10-1.35). A concerted mechanism involving predominant frontside nucleophilic attack is proposed on the basis of the primary normal DKIEs and selectivity parameters. Hydrogen bonded, four-center-type transition state is proposed. The steric effects of the two ligands on the anilinolysis rates of the chlorothiophosphates are discussed. The anilinolyses of P=S systems are compared with those of their P=O counterparts on the basis of the reactivities, thio effects, selectivity parameters, and DKIEs.

• KDI Journal of Economic Policy
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• v.39 no.3
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• pp.19-41
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• 2017

This paper examines the aspects of changes in China's consumer market since the mid-1980s. By comparing urban and rural residents' expenditures, I find that the rural consumer market has exhibited extraordinary growth. Over the past decade, the consumption growth rate and average propensity to consume by rural residents have surpassed those of their urban counterparts, with the former's consumption patterns becoming increasingly similar to the latter's. Such a phenomenon prevails in rural areas which neighbor second-and third-tier cities where urbanization is progressing rapidly. These findings imply that Korean companies need to diversify their export goods in line with China's expanding rural markets while further differentiating their product composition to satisfy the heterogeneous demands in urban areas. With regard to the government, efforts must be made to strengthen the export cooperative system so that it targets not only urban but also rural markets in China.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.151.1-151.1
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• 2016

Complex oxide heterointerfaces have been extensively explored in the past due to the novel phenomenon emerging at such interfaces that differ from their individual bulk counterparts. The integration of a ferromagnetic (FM) material with the superconducting (SC) material leading to proximity effect is one of the commonly studied phenomenon in these heterostructures. In continuation, we have stabilized the FM layer La0.7Ca0.3MnO3 (LCMO) on SC material YBa2Cu3O7-${\delta}$ (YBCO) using pulsed laser deposition technique and explored the structural, magnetic, electrical and magneto-transport properties of this heterostructure. ${\Phi}$-scan measurements confirm the epitaxial nature of LCMO/YBCO heterostructure grown on single crystalline SrTiO3 substrate. The FM transition of LCMO and SC transition of YBCO are observed in the magnetization measurements of the bilayer structure. Through electrical measurements, we understood that the proximity effect leads to lowering of the SC transition of YBCO. The role of interface in the bilayer structure is also realized through electrical transport measurements.

• Journal of Navigation and Port Research
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• v.40 no.5
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• pp.317-328
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• 2016

The steady growth of seaborne trade has resulted in the further development of container ships, ports, and container terminals, and the operating efficiency of a container terminal is a decisive element for its competitive ability in international markets. The aim of this research is to evaluate the relative efficiency of Russian and South Korean container terminals. For this purpose, the output-oriented DEA was applied to 31 container terminals of Russian and South Korean seaports for the years from 2012 to 2014. The results indicate that Korean container terminals exhibited higher efficiency scores than their Russian counterparts.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.1
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• pp.37-44
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• 2018

In this work, a 4-DOF industrial robot system with three translational and one rotational motions which is widely used in palletizing applications is developed. In order for small robot manufacturing companies to develop their own robot systems for CNC machining and/or general automations, the analysis and design methods of a 4-DOF robot manipulator are presented and the development of a PC-based robot controller with EtherCAT are introduced. It is noted that the robot controller is developed by using Simulink Real-Time, which can provide an integrated environment of easier control algorithm development and data logging. Through position control and accuracy/repeatability measurement results, the developed robot prototype has comparable performances with commercial counterparts. In the future works, the advanced functions of industrial robots such as kinematic calibration, vibration suppression control, computed torque control, etc. will be investigated.

• Progress in Superconductivity and Cryogenics
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• v.20 no.1
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• pp.23-27
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• 2018

As the wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air, there are advantages compared with the wired counterparts, such as convenient, safety and fearless transmission of power. From this reason, the WPT systems have started to be applied to the wireless charging for various power applications such as train, underwater ship, electric vehicle. This study aims for the effect and characteristics of different inserted resonance coil between Tx and Rx coils for charging system of superconducting magnetic levitation (MAGLEV) train. The transfer efficiency and effect are evaluated with helix type, rectangular type copper resonance coil, and HTS resonance coil under bulb and HTS magnet load, respectively. The input power is adapted with radio frequency (RF) power of 370 kHz below 500 W.

• Communications for Statistical Applications and Methods
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• v.22 no.6
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• pp.625-637
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• 2015

We develop a Bayesian clustering procedure based on a Dirichlet process prior with cluster specific random effects. Gibbs sampling of a normal mixture of linear mixed regressions with a Dirichlet process was implemented to calculate posterior probabilities when the number of clusters was unknown. Our approach (unlike its counterparts) provides simultaneous partitioning and parameter estimation with the computation of the classification probabilities. A Monte Carlo study of curve estimation results showed that the model was useful for function estimation. We find that the proposed Dirichlet process mixture model with cluster specific random effects detects clusters sensitively by combining vague edges into different clusters. Examples are given to show how these models perform on real data.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.309-310
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• 2016

Sealed flooded lead acid batteries are becoming popular in the industry because of their low cost as compared to their counterparts. State of Charge (SOC) estimation has always been an important factor in battery management systems. For the accurate SOC estimation, open circuit voltage (OCV) hysteresis should be modelled accurately. The hysteresis phenomenon of the sealed flooded lead acid battery is discussed in detail and its ultimate modeling is proposed based on the conventional parallelogram method. The SOC estimation is performed by using Unscented Kalman Filter (UKF) while the parameters of the battery are estimated using Auto Regressive with external input (ARX) method. The validity of the proposed method is verified by the experimental results. The SOC estimation error by the proposed method is less than 3 % all wing the 125hr test.

• Membrane and Water Treatment
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• v.9 no.6
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• pp.393-403
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• 2018

In this research commercial polyethersulfone (PES) membrane was modified using $TiO_2$ nanoparticles (P-25 Degussa) and further irradiated using UV light to overcome the hydrophobicity and fouling nature of the membrane. Further the membranes were characterized using SEM and FTIR. Contact angle measurements study confirmed the hydrophilic tendency of the modified membrane by decreasing the contact angle from $73^{\circ}$ to $20.28^{\circ}$. The modified membranes showed higher flux and better anti-fouling properties as compared to the unmodified counterparts. The optimum conditions were found to be 0.5 wt% $TiO_2$ loading with 60 min membrane immersion and 10 min UV light illumination. The effect of different pH conditions of feed was analysed. Real wastewater filtration experiments also indicated better performance of modified membranes as opposed to neat PES membranes.