• Journal of Power Electronics
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• v.18 no.5
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• pp.1369-1379
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• 2018

In this paper, a model predictive torque control (MPTC) without the use of a weighting factor for surface mounted permanent-magnet synchronous machine (SPMSM) drive systems is presented. Firstly, the desired voltage vector is predicted in real time according to the principles of deadbeat torque and flux control. Then the sector of this desired voltage vector is determined. The complete enumeration for testing all of the feasible voltage vectors is avoided by testing only the candidate vectors contained in the sector. This means that only two voltage vectors in the sector need to be tested for selecting the optimal voltage vector in each control period. Thus, the calculation time can be reduced when compared with the conventional enumeration method. On the other hand, a novel cost function that only includes the dq-axis voltage errors between the desired voltage and candidate voltage is designed to eliminate the weighting factor used in the conventional MPTC. Thus, the control complexity caused by the tuning of the weighting factor is effectively decreased when compared with the conventional MPTC. Simulation and experimental investigation have been carried out to verify the proposed method.

• Fashion & Textile Research Journal
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• v.8 no.1
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• pp.55-63
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• 2006

The purpose of this study examines difference of cunsumer satisfaction by expected selection attribute of wedding dress and bride make-up. It is looking into influencing variables in consumer satisfaction, and is supplying real information to wedding market. The subjects of this study were 241 women getting married within one year of Daegu. The data were analyzed by using frequency, mean, the standard deviation, ANOVA, duncan test, correlation analysis, cross-analysis. Conclusion obtained from the results and discussions of the research are as follows: 1) In the attribution of expected selection according to occupation, blue-collar women are concerned about cost factor but they are low content with the perceptual satisfaction factor. 2) When selecting places for wedding dresses and wedding make-up, in the attribute of expected selection about the number of visiting the shop for wedding dresses and make-up, people who visit over 7 dress shops are highly interested in the appearance fancy degree, advertisements effect factors. But they are concerned with advertisements effect factor, cost factor in the perceptual satisfaction factor about wedding dress. Besides, the more they get chances to visit many dress shops, they are concerned with advertisements, cost factors, and satisfied with both the effect of advertisements and appearance factor degree in the attribution of expected selection about wedding make-up. 3) In the attribution of expected selection about the cost of wedding dresses and make-up, the lower the cost paid, people are interested in price factor. Furthermore, in the attribution of expected selection about the wedding dress and make-up cost, those who spent over 150 million Won are interested in quality, others influence factor, and the case of less than 120~150 million Won, people are highly interested in the appearance fancy degree, advertisements effect factor, and the women are satisfied with the advertisement effect factor in the perceptual satisfaction factor of wedding make-up.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.490-499
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• 2015

In this study, for the introduction factors of ERP system suggested in the prior study, I analyzed the importance of each introduction factor by using Delphi methodology and AHP. As a result of analysing the importance of the introduction factors of the 1st layer, the supplier factor was analyzed to be the most important factor among innovation factor, information technology factor, the user factor, the supplier factor, and in the weight analysis on the 2nd layer considering the importance of 1st layer, the standard work model of the supplier factor was a suitable factor, and the CEO participation factor(.086) was analyzed as the second most important introduction factor. These analysis results enable to determine that domestic Small & Medium enterprises' position hope to introduce by selecting a system in which the company characteristics and management strategies are applied well, because they should operate an ERP system that has already been developed, and in this course, the participation of CEO was also found to be a very important factor.

• Journal of Korea Port Economic Association
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• v.18 no.2
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• pp.65-90
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• 2002

Despite the importance and necessity, the 3PL has not been activated to date. Among many views, customers claim that logistics service provider(LSP) are not prepared or capable of offering satisfactory 3PL services, while LSP emphasize the lack of mutual trust, closed corporate culture of the customer and excessive demand for reducing the costs. With this keeping in mind, it surveyed difference of perception between users and providers of 3PL services in terms of the actual status of using 3PL services, the degree of satisfaction and key factors for selecting 3PL provider through the questionnaire. As shown in this study, 43.3％ of the respondents outsourced logistics services. However, Most company outsourced only inland transportation (49.5％) which is a simple and limited scope of 3PL services, but it also indicated that the percentage of users have ranged was less then 10% in outsourcing their whole logistics sector to 3PL provider and employing other logistics functions. Among respondents, a majority of the service provider stated that they offered satisfactory cost-saving to the customers, while users felt that the degree of satisfaction for using 3PL services was evaluated as at an average level and they more highly regarded the strong partnership of their 3PL provider rather than the saving of cost and improvement of customer's services. Moreover, in contrast to the 3PL providers which regard the most important factor for selecting 3PL service provider is the logistics cost quoted, users of 3PL services felt that the quality of services was more significant than the reduction of cost, and this tendency for selecting 3PL providers was shown in more advanced countries. While users of 3PL services indicated that the main reason for not using 3PL services was to avoid disclosing information of their business and it costs much for employing 3PL providers than doing themselves, 3PL providers thought it was due to reluctancy of opening information and resistance from the logistics division engaged in logistics activities concerned. Accordingly, providers and users of 3PL services should trust each other and prepare plan to activate 3PL services under the collaborative relationships as soon as possible.

• 전기의세계
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• v.17 no.3
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• pp.39-42
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• 1968

We have been studying on the discharged phenomena if compound dielectrics for insulator which is very important in electric machinery and et al. In this paper we come to the couclusion that as a result of studying on the electric design of Ozonizer, the higher frequency becomes the better output could be got, and then discharge power could be the greatest by selecting the distance of the discharge gap and atomospheric pressure properly under the same applied voltage, and that power factor of the Ozonizer reached the maximum power at a particular frequency when the discharge power is maintained at constant.

• The Journal of Information Systems
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• v.14 no.1
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• pp.19-40
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• 2005

The history of computer virus comes along with that of computer. Computer virus han surfaced as a serious problem in information age. The advent of open network and widespread use of Internet made the problem even more urgent. As a method of defense for computer virus most companies use anti-virus software. Selecting appropriate anti-virus software involves various criteria and thus it is a multiple-attribute decision making problem. The purpose of this study is to prioritize anti-virus software evaluation factors. To do that, first of all, important evaluation factors are selected based on previous research on anti-virus software as well as general software evaluation models. Then, a questionnaire survey was conducted on end-users, system administrators and anti-virus software developers. The survey result was analyzed with ExpertChoice 2000 which is based on Analytic hierarchy Process technique. This study found that there are clear differences among three survey groups regarding the relative importance of overall evaluation factors. End-user group ranked "cost" first, but it was the least important factor to developer group. Developers pointed out "operational support" ad the most important factor. There were also obvious differences in the relative importance of detail evaluation items. Both end-users and system administrators shared 7 common items among top 10 most important items. Moreover, neither of the two groups ranked any of the items in the "operational support" factor in top 10, whereas all 4 items in the factor were included in top 10 by developer group.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.6
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• pp.937-954
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• 2010

This study analyzes the body characteristics of Korean obese women using 2004 Size Korea data. For selecting the obesity sample, 7 obesity judgment indices were chosen from previous clothing-related studies. A total of 636 females defined as "obese" by 5 out of 7 indices were selected as subjects for this study. 54 body measurements and obesity judgment indices were used. First, the subjects had a BMI 27.11, R$\ddot{o}$hrer index 1.76, Vervaeck index 104.77, Relative weight 133.00, and WHR 0.90. In the case of the distribution by age groups, the twenties were 6.4% of the entire subjects, the thirties were 18.2%, the forties were 16.4%, the fifties were 37.4%, and the sixties were 21.5%. The result of the ANOVAs (divided into 5 age groups) showed significant differences in 41 measurement items except for bust circumference, waist length front, and all of obesity judgment indices. Second, according to the ANOVAs among stature groups divided by 5cm pitches there are significant differences in all measurements except for bust circumference. The results of the ANOVAs among bust circumference groups divided by 5cm pitches show that significant differences were observed in all measurements except four measurement items (including body rise). According to the ANOVAs among the waist circumference groups divided by 5cm pitches, there are no significant differences in all height measurements and shoulder length, waist to hip length, and crotch length. It is confirmed that stature and bust circumference have a deep relationship with measurements other than waist circumference. Third, as the factor analysis were conducted using 39 measurement items to extract the body characteristics of obese women Factor 1 is "circumference measurements & obesity judgment indices," Factor 2 is "heights & arm-related lengths," and Factor 3 is "size and ratio of waist circumference & hip circumference." Factor 4 was "lengths in upper body," Factor 5 was "back width in upper body," Factor 6 was "side neck point to bust & bust circumference," Factor 7 was "length in lower body & arm circumferences," and Factor 8 was "neck base circumference & front widths in upper body." These 8 factors explained 76.54% of the total variance.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.1
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• pp.18-28
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• 2006

Some issues which should be considered in an R&D project selection problem are as follows: First, quantitative analysis on the efficiencies of R&D projects is required to guarantee objective validity in the evaluation of the projects. For this reason, the methodology for selecting R&D projects should be based on mathematical models that perform quantitative analysis. Second, in general there are ordinal factors like Likert-scale in the data for evaluating R&D projects. Previous researches, however, couldn't suggest explicit methods incorporating these ordinal factors into models. Third, for the R&D project selection problems with limited resources like budget, it is necessary to decide the perfect ranking of the all projects. This paper develops a mathematical model that can be applicable to the problems of selecting R&D projects with the previous features. In this paper, we improve the original DEA model for evaluating efficiency to incorporate ordinal factors and suggest a new model which can decide the perfect ranking of all projects by merging the improved DEA model and AHP method. Furthermore a web-based R&D project selection system using the DEA/AHP model suggested in this paper is developed and illustrated.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.498-500
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• 2004

QPSK (Quaternary Phase Shift Keying) will be adopted as the modulation of HRIT (High Rate Information Transmission) which is transmitted to COMS (Communication, Ocean and Meteorological Satellite) through HPA (High Power Amplifier) in ground segment. Due to the nonlinearity of HPA, IMD (Inter-Modulation Distortion) of multi-carrier signals and PAPR (Peak-to-Average Power Ratio) of modulated HRIT must be considered to estimate the output power of HPA. In this paper, we measured the PAPR to various the roll-off factor of RRC (Root Raised Cosine filter) which is filtering the modulated HRIT signal for reducing ISI (Inter-Symbol Interference) and bandwidth. It was found that the minimum PAPR is 2.78dB at 0.5 of roll-off factor for scrambled data. It's 2.78dB of P APR will be in output power selecting in COMS earth station.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.1
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• pp.70-76
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• 1998

A switch-mode AC/DC converter with high input power factor and sinusoidal input current waveforms is analyzed and modelled for computer simulation. The developed mathematical model for this converter can be used to examine the transient and steady-state performance for selecting the proper ratings of filter, boost inductor and semiconductor devices or the effects of this converter under normal and fault operating conditions on the associated power systems. The proposed model and computer programs are confirmed by comparing with the experimental results.