• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.1-12
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• 2017

Recently, the Go game has been performed between the 'AlphaGo' of the DeepMind and Lee Sedol, a famous professional Go-player of Korea, which leads to arise a lot of interests in the AI (Artificial Intelligence) research area. Based on the Fuzzy logic of the AI, we have also developed another game's AI, .i.e., the Yutnori game, one of Korean traditional board games. However, it is not easy and simple to consider all the cases of the Yutnori game since it is a non-perfect information game in terms of the AI. Thus, we have developed the Fuzzy-logic-based AI which tries to simulate humans' selections, meaning that the suggested AI has focused on the humans' choices depending on diverse situations in the Yutnori. With our extensive simulations using the suggested Yutnori AI, we have analyzed its performances with respect to 10 Yutnori situations among various scenarios. In conclusion, our suggested AI have demonstrated that 6 out of 10 situations are exactly same with the humans' choices and the rest 4 cases are also similar to that of human's, which reveals that our Fuzz-logic-based Yutnori AI can effectively simulate human's choices.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1965-1969
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• 2011

1,2,4,5-tetraoxane, mono and dinitrate glycerol carbonate ester derivatives of stearic acid were synthesized along with the known 9(10)-keto methyl sterate, methoxy mono-nitrate and dinitrate of methyl stearate. Their cetane numbers (CNs) were investigated to evaluate their viability for use as CN improvers. The CN performances of tetraoxane and all of the nitrate derivatives were investigated at 500 and 1000 ppm concentrations and compared to that of a traditional CN improver 2-ethylhexyl nitrate (2-EHN). The experimental results suggest that all derivatives evaluated in this study showed better CN improvement than base diesel fuel. Specifically, the 1,2,4,5-tetraoxane derivative of stearic methyl ester was superior to all derivatives studied, also being superior to 2-EHN. We also discussed the correlations between the observed CN trends and thermo-analytical data resulted from thermo gravimetric analysis curves (TGA) and differential scanning calorimetry (DSC).

• Korean Journal of English Language and Linguistics
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• v.3 no.2
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• pp.281-308
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• 2003

The purpose of this study is to determine the effects of CMC-based English learning. In this study, CMC components were found to provide circumstances of facilitating interactions between student-student and student-student-teacher, which enabled students to accomplish language learning tasks. Findings of this study are as follows: First, CMC based language learning experience helps students have positive attitudes toward their English language learning. Second, student-student-instructor interaction group outperformed other groups in academic achievement and class activity participation. Third, cooperative learning groups more actively participated in the class activity than the individual learning group resulting in better academic performances. These findings supported the fact that cooperative learning with CMC components are useful in bringing more class participation and positive attitude that were believed to foster language learning than other groups in traditional language learning environments. This study suggests that the instructor needs to use instructional design strategies helpful to facilitate active interactions between instructors and students in order to achieve better effectiveness of English learning in a CMC based learning environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2080-2085
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• 2008

KEPCO's AMR (Automatic Meter Reading) is a system that performs the real-time inspection and management of the 15-minute load profile of electric power consumption through a wired and/or wireless network such as CDMA. It has been utilized widely for real-time collection and data analysis. So far, KEPCO has focused on establishing wireless networks using CDMA and collecting data in real time but failed to consider sufficiently performances that can improve the quality of the original data required in terms of data utilization as well as establish the summary information. In this paper, we are going to show the functions that improve data quality by recording the final renewal time of any erroneous data and maintaining such data lists to use them in the rebuilding of summary information. The goals are to reduce any load applied mainly on the DBMS (Database Management System) of AMR, to enable the real-time performance of establishment in the summary information, and to obtain high-quality inspection data. The performance evaluation result has revealed a 10-fold improvement compared to the traditional disk-based DBMS system when the summary information is established.

• Journal of the Korean Society of Costume
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• v.28
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• pp.169-186
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• 1996

Wangeja Chulgungdo (The Painting for a Crown Prince's Outgoing for Schooling to Sungkyunkwan) for this study which is held by the Korean university Museum is a kind of documentary paintings which not only have the value of art history but also give a glimpse of the court ceremonies for a Crown Prince. This painting offers various historical clues to understand the procedure for a Crown Prince's official entrance of Sungkyunkwan participants of the ceremony and other ceremony-related items$\ulcorner$Wangseja chulgungdo$\lrcorner$ was the painting drawn for a series of court procedures of Crown Prince Munjo's official en-trance of Sungkynkwan. When he was old enough to begin learning Sohak on March 11. 1817 that is ; he held Heonjakrye(a ceremony for offering drinks to the ancestors) at Munmyo passed Iphakye(a ceremony for en-trance of school) at Myungryundang and received Suharye the next day. $\ulcorner$Wangseja Chulgungdo$\lrcorner$ had the strong char-acteristics of documentary paintings in terms of art history which was intended to leave the historical event of a Crown Prince's entrance. It reflected the traits of documentary painting style in late Chosun Dynasty; a technique that strongly relieved the ceremonial scenes against the background such as mountains and rivers; a painting that not only captured the vivid actions of personalities ar the crucial moment of the ceremony but also depicted the cer-emonial vessels and items very realistically. Authors could confirm the ceremonial think-ing of the traditional society through a Crown Prince's entrance which controlled the details of every part of the performances of the court ceremony.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.135-142
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• 2016

Generally, closed slots are adopted to reduce the water friction loss in both the stator and the rotor of water filling submersible motor due to the special environment of operation. One of the obvious differences between the traditional induction motors and water filling submersible motors is that the submersible motors only need relatively smaller starting torque. This paper aims to analyze the slot leakage reactance of water filling submersible motor during starting transient operation. An improved analytical method which considered the magnetic saturation of the slot bridge and the skin effect of rotor bars is proposed. The slot permeance factor which has a direct impact on the slot leakage reactance is calculated. Then finite element models with different stator slot types are constructed and search coils are introduced to measure the slot flux linkage. Moreover, the starting performances of the models with two typical stator slots are compared and the flux leakage characteristics are obtained. Finally, the results obtained by finite element method are very close to the results obtained by analytical method.

• The Korean Journal of Health Service Management
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• v.10 no.2
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• pp.15-23
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• 2016

Objectives : The purpose of this study was to evaluate the productivity changes of 18 public health centers in Gangwon-do from 2006 to 2013 using the Malmquist Productivity Index(MPI). Methods : Data were collected from Statistics Korea from 2006 to 2013. The input variables were the numbers of medical, nursing and administrative personnels. The output variables were the performances of health promotion programs. Along with the traditional input-oriented DEA analysis, the MPI was calculated. Results : First, among the 18 public health centers, the productivity index of 14 public health centers was increased. Second, the annual productivity showed a 6% increase. Third, the productivity improvements were mainly caused by Scale Efficiency Change. Conclusions : Improving the productivity of public health centers requires the support and external policies of the national and local government. Internally, public health centers need to maintain scale optimization of the center. Additionally, efforts should be made to effectively use limited resources.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.4
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• pp.213-224
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• 1998

Since the late 1980s, an Increasing number of neural network models have been studied in the areas of financial prediction and analysis. The purpose of this study is to Investigate the possibility of building a neural network model that is able to construct a profitable trading strategy in the Korean Stock Market. This study classifies stocks into the future market winners and losers from the publicly available accounting information and builds portfolios based on this information. The performances of the winner portfolios and the loser portfolios are compared with each other and against the market index. The empirical result of this research is consistent with the traditional fundamental analysis where it is claimed that the financial statements contain firm values that may not be fully reflected In stock prices without delay. Despite the supporting empirical evidence. It is somewhat Inconclusive as to whether or not the abnormal return in excess of market return is the result of the extra knowledge obtained in the neural network models derived from the historical accounting data. This research attempts to open another avenue using neural network models for searching for evidence against market efficiency where statistics and intuition have played a major role.

• Wind and Structures
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• v.26 no.6
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• pp.383-395
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• 2018

An accurate determination of wind speed distribution is the basis for an evaluation of the wind energy potential required to design a wind turbine, so it is important to estimate unknown parameters of wind speed distribution. In this paper, Gumbel distribution is used in modelling wind speed data, and alternative robust estimation methods to estimate its parameters are considered. The methodologies used to obtain the estimators of the parameters are least absolute deviation, weighted least absolute deviation, median/MAD and least median of squares. The performances of the estimators are compared with traditional estimation methods (i.e., maximum likelihood and least squares) according to bias, mean square deviation and total mean square deviation criteria using a Monte-Carlo simulation study for the data with and without outliers. The simulation results show that least median of squares and median/MAD estimators are more efficient than others for data with outliers in many cases. However, median/MAD estimator is not consistent for location parameter of Gumbel distribution in all cases. In real data application, it is firstly demonstrated that Gumbel distribution fits the daily mean wind speed data well and is also better one to model the data than Weibull distribution with respect to the root mean square error and coefficient of determination criteria. Next, the wind data modified by outliers is analysed to show the performance of the proposed estimators by using numerical and graphical methods.

• Journal of the Korean Operations Research and Management Science Society
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• v.21 no.3
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• pp.109-125
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• 1996

Biases and errors in the human being's reasoning process have been studied continuously by the researchers, especially psychlogists and social scientists. These bias phenomenon is classified on the basis of the origin, i. e. motivation and cognition. Furthermore the necessity of research on the bias in the management and management information system areas in increased more and more recently, which have their academic backgrounds in the psychology and social science. The biased information stream is transformed into the systematic error due to the motivation and cognitive bias of human-being, then its resulting phenomena are as follows; 1. the availability of salient information 2. preconceived ideas or theories about peoples and event 3. anchoring and perseverence phenomena. In order to reduce the information errors, Satty suggested the Analytic Hierarchy Process (AHP) that is the subject of this paper and that is widely used for evaluation of complex decision making alternatives. THerefore this paper studies AHP's effects and its limitations in applying to the management area. Thus this paper compared the performances of the 3 models : 1 the traditional additive regression model. 2 regression model using the factor score, and 3 the regression model with AHP. As a result, 3 models produce the different outcomes.