• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.7
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• pp.483-487
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• 2000

The analysis of current distribution in a solidly modeled coil is very important for accurate of electric machines such as deflection yoke. In general, Modeling every coils is nearly impossible for analyzing magnetic field using the 3-D finite element method, so solidly modeled coil is usually used. Some methods have been developed for analyzing current distribution, but these methods have fatal disadvantages. The main disadvantages are that the methods cannot be applied to an arbitrary shaped coil and that they yield numerical errors. In this paper, a novel method for resolving the problems mentioned above is proposed. The new method is verified by the application to a test model and it shows a very accurate result.

• Journal of Applied Reliability
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• v.3 no.1
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• pp.13-40
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• 2003

The seasonal adjustment is an essential process in analyzing the time series of economy and business. One of the powerful adjustment methods is X11-ARIMA Model which is popularly used in Korea. This method was delivered from Canada. However, this model has been developed to be appropriate for Canadian and American environment. Therefore, we need to review whether the X11-ARIMA Model could be used properly in Korea. In this study, we have applied the method to the annual sales of refrigerator sales in A electronic company. We appreciated the adjustment by result analyzing the time series components such as seasonal component, trend-cycle component, and irregular component, with the proposed method. Additionally, in order to improve the result of seasonal adjusted time series, we suggest the demand forecasting method base on autocorrelation and seasonality with the X11-ARIMA PROC.

• Proceedings of the Korea Society of Design Studies Conference
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• 1998.10a
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• pp.44-45
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• 1998

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.211-219
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• 2013

The analysis method using Big Data has evolved based on the Big data Management Technology. There are quite a few researching institutions anticipating new era in data analysis using Big Data and IT vendors has been sided with them launching standardized technologies for Big Data management technologies. Big Data is also affected by improvements of IT gadgets IT environment. Foreran by social media, analyzing method of unstructured data is being developed focusing on diversity of analyzing method, anticipation and optimization. In the past, data analyzing methods were confined to the optimization of structured data through data mining, OLAP, statics analysis. This data analysis was solely used for decision making for Chief Officers. In the new era of data analysis, however, are evolutions in various aspects of technologies; the diversity in analyzing method using new paradigm and the new data analysis experts and so forth. In addition, new patterns of data analysis will be found with the development of high performance computing environment and Big Data management techniques. Accordingly, this paper is dedicated to define the possible analyzing method of social media using Big Data. this paper is proposed practical use analysis for social media analysis through data mining analysis methodology.

• Journal of Korean Society on Water Environment
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• v.30 no.5
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• pp.512-516
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• 2014

Two different methods for TOC (Total Organic Carbon) analysis of livestock manure including high strength solid organics were evaluated. Firstly, an analyzing method by dilution after pre-treated by Ultrasonicator and 100 mesh sieve for homogenization was defined as TOC 1; and secondly method divided by particulate organic carbon (POC) and dissolved organic carbon (DOC) was defined as TOC 2. 116 samples collected from 56 farms were analyzed in TOC1, TOC2, BOD and VSS. TOC1 method showed higher accuracy at less than 30,000 mg/L of TOC while TOC2 method presented significant reliability at over that concentration. Regarding to the sample with the same VSS concentration, the correlation between TOC 2 and VSS (${\rho}$: 0.806) was slightly higher than that between TOC 1 and VSS (${\rho}$: 0.784), resulted from a relatively low loss of solids and a low error probability (dilution and homogenization effects) in the analyzing procedures. In addition, the reliability between POC and VSS in TOC2 was high and the POC was about 4.4 fold that of the VSS. Consequently, TOC 2 without dilution effect was assessed as a proper method to increase the analyzing accuracy of swine manure including high solid organics.

• Journal of the Korean housing association
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• v.22 no.4
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• pp.71-81
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• 2011

This study aims to make evaluation method as a means to evaluate the crime prevention through environmental design of multi-family housing. According to the analysis of correctness and usefulness of evaluation method in multi-family housing, the preliminary evaluation method is selected. The correctness and usefulness of evaluation method is examined by 2 works. One is analyzing the results of experts' advice about evaluation method. The other is analyzing the results of the case studies of 3 housing sites. Those improve evaluation method to measure the crime prevention through environmental design objectively. As a result, the system of classification is divided into evaluation area and evaluation item. Evaluation area is sorted into four types, i.e. public space, semi-public space, semi-private space, and equipment. Evaluation scores according to evaluation area are different. Evaluation scores of public space are 73. Those of semipublic space are 196. Those of semi-private space are 75, Those of equipment are 28. Evaluation item is divided into 20 items. 20 items are; the entrance of complex, apartment building, recreational space and parking space etc. Checklists according to evaluation items are proposed and detail evaluation criteria according to checklist are proposed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.2
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• pp.181-186
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• 1994

This paper applicate the digital elevation model(DEM) method in geographic information systems(GIS) on the earthwork volumes, intending to present an efficient geographic information-obtain method and an optimum earthwork volumes method after analyzing the obtain method of geographic informations which are made up of as spatial data(X, Y) and attribute data(Z), analyzing area determination method by geographic information-obtain method each other and the accuracy of earthwork volumes computation. The results of this paper showed that the method of earthwork volumes computation, which was based on the earthwork volumes-calculation grid applied by the DEM method of based grid to randomly get the geographic information of geographic transformation point and translated geography into nonlinear and unequal interval, was very efficient.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.419-427
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• 2016

This paper proposes a design method of LCL-filter for a grid-connected three-phase inverter using a discontinuous PWM (DPWM) method. When using a DPWM method, many harmonic voltages are generated in the inverter output compared to a continuous PWM (CPWM) method. Therefore, an optimized grid-connected filter design is required for a DPWM method. The proposed design method provides generalized formula to design accurate LCL-filter without trial and error procedures. An inverter side inductance is designed by analyzing the current ripple injected to the grid. The Optimized parameters of LCL-filter can be designed by analyzing the total harmonic distortion (THD) and the ripple attenuation factor of the output current. The proposed LCL filter design method is demonstrated by simulation and experimental results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2871-2877
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• 2015

Shopping patterns are changing with the emergence of SNS. Recently, it is also interested in providing the information based on the users' needs. Generally, the provided information is obtained from the history of users' simple browsing. Best selling hot item list is also provided in order to reflect the preferences of public users. However, the provided information is irrelevant to an individual preference. In this paper, we propose a method to utilize inner and outer SNS for analyzing public preferences about goods which are interested by individual users. The inner analyzing module collects and analyzes the preferences of community members about two goods designated by individual users. The outer analyzing module supports to analyze public preferences by using the tweeter SNS. The results of implementation show that it is possible to recommend goods based on the individual users' preferences unlike the existing shopping mall.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.199-207
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• 2013

Recently, hacking is seen as a criminal activity beyond an activity associated with curiosity in the beginning. The malignant bot which is used as an attack technique is one of the examples. Malignant Bot is one of IRC Bots and it leaks user's information with attacker's command by attacking specified IP range. This paper will discuss an access method and a movement process by analyzing shadowbot which is a kind of a malignant Bot and will suggest possible countermeasure. This study has two distinct features. First, we analyze malignant Bot by analyzing tools such as VM ware. Second, we formulate a hypothesis and will suggest possible countermeasure through analyzing malignant Bot's access method and movement. Performance evaluation will be conducted by applying possible countermeasure to see if it can prevent attacks from malignant bot.