• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.2
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• pp.119-126
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• 1999

Current transformer (CT) saturation may cause a variety of protective relays to malfunction. The conventional CT is designed that it can carry up to 20 times the rated current without exceeding 10% ratio error. However, the possibility of CT saturation still remains if the fault current contains substantial amounts of ac and/or dc components. This paper presents a design method of iron-cored CTs for use with protective relays to prevent CT saturation. The proposed design method determines the core cross section of the CT; it employs the transient dimensioning factor to consider relay's operating time (duty cycle) and dc component as well as ac components contained in the fault current, and symmetrical short-circuit current factor to consider as well as ac components contained in the fault current, and symmetrical short-circuit current factor to consider the biggest fault current. The method designs the cross section of CTs in cases of reclosure and no reclosure.

• Journal of the Korean Data and Information Science Society
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• v.17 no.4
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• pp.1329-1341
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• 2006

When X and Y have independent gamma distributions, we consider the testing problem for two gamma means. We propose a solution based on a Bayesian model selection procedure to this problem in which no subjective input is considered. The reference prior is derived. Using the derived reference prior, we compute the fractional Bayes factor and the intrinsic Bayes factors. The posterior probability of each model is used as a model selection tool. Simulation study and a real data example are provided.

• Journal of Applied Reliability
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• v.10 no.1
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• pp.25-38
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• 2010

In this paper, an accelerated degradation test procedure for an electronic appliance compressor is proposed. We investigate the amount of wear of the compressor and consider several factors as accelerating factors. Finally we select the operating pressure as a main accelerating factor. The test condition of accelerated degradation test is determined. The modified accelerating test reduces the test time in design phase by using the suggested accelerating factor.

• MALSORI
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• no.67
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• pp.79-102
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• 2008

In this paper, we investigate the relation between Bayes factor and likelihood ratio test (LRT) approaches and apply the neighborhood information of Bayes factor to building an alternate hypothesis model of the LRT system. To consider the neighborhood approaches, we contemplate a distance measure between models and algorithms to be applied. We also evaluate several methods to improve performance of utterance verification using neighborhood information. Among these methods, the system which adopts anti-models built by collecting mixtures of neighborhood models obtains maximum error rate reduction of 17% compared to the baseline, linear and weighted combination of neighborhood models.

• Journal of the Korean Data and Information Science Society
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• v.17 no.3
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• pp.843-850
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• 2006

In this paper, we consider the Bayesian multiple comparisons problem for K bivariate exponential populations to make inferences on the relationships among the parameters based on observations. And we suggest the Bayesian procedure based on fractional Bayes factor when noninformative priors are applied for the parameters. Also, we give a numerical examples to illustrate our procedure.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1310-1320
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• 2007

This study investigated the differences in the importance of store characteristics depending on on-line clothing store type and consumer age. The questionnaires were given to female residents in the ages between 20-39 in Seoul and Kyung-gi province during October 2006. The results were summarized as follows: 1. By analyzing the differences in importances of on-line store characteristics factors it was found that buying process service factor and product searching system factor were important in on-line general merchandise store. and buying process service factor and product factor(all the factors, such as store credit, product, screen-displayed design, searching and approaching system, customer management service) were important in on-line specialty store. 2. By analyzing the differences in importances of on-line store characteristics depending on the store type, buying process system such as refund policy, shipping, high-speed payment and rapid searching, screen-displayed design system, approaching and searching system were more important in on-line general merchandise store when comparing to specialty store. It also showed that the consumer considered the reputation of the store and its image more important in on-line general merchandise store. 3. By analyzing the differences in of on-line clothing store importance depending on age, in the case of on-line general merchandise store, it showed that people in their thirties regarded buying process service factor more important than twenties, and when it came to the product and searching system, it was vice versa. Twenties had a tendency to consider the aspect of product important and, relatively, thirties regarded searching and approaching system factor important. in the case of specialty store. It was found that women in their twenties had a tendency to consider product factor more important.

• Journal of Korean Physical Therapy Science
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• v.18 no.2
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• pp.9-15
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• 2011

Purpose: The purpose of this study was to provide the information of renal disease patients and to provide evidence the physical therapy recipient of renal disease patients. The reviews suggest that renal disease patients are physical inactivity situation, increase on cardiopulmonary risk factor, developed complication disease, increased psychosocial factor like depress and anxiety, decreased Quality of life because their disease effects. Thus. exercise program seems to have beneficial effect on physiologic and psychosocial functioning, Quality of life. It is expected that this study will consider rehabilitation program for internal medicine patients and should be consider as availability of therapeutic exercise program on understanding renal disease in physical therapy.

• Culinary science and hospitality research
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• v.11 no.1
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• pp.87-104
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• 2005

A lifestyle changes according to environment. It appears more in the dietary life connected with the necessities in life. This study is executed empirically through the questionnaire that consists of selection attribute and variables connected with "well-being" that is examined in empirical analysis. It was carried out for 20 days from July 15 to August 5, 2003 with the customers who live in Seoul and the suburbs. With collected data, there were frequency analysis and factor analysis, reliability analysis using SPSS 10.0 packages, and T-test and ANOVA were enforced for the verification of differences between demographic elements with each factor. The result indicates that the inclinations of customers changed from the "well-being" trend have four factors: health consideration factor, food materials factor, cooking factor, and habit factor. And the housewife group shows the great changes in habit factor. In case of the changes according to incomes, the larger income earners tend to consider health more. In conclusion, people came to prefer the healthy Korean style food from the well-being trend.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.215-223
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• 2007

On-Line Shopping mall is becoming important strategic environment that decide corporation's competitive advantages because of that can achieve quality of customer service and offer speed elevation through both-way communication effectively. Accordingly, as interest about electronic commerce rises, various research had been gone. But, most researches are applying off-line market's quality of service measurement tool just as it is doing not consider special quality of internet. Consider and prescribe by system quality, and saw that thing with grasp relation with customer satisfaction along with qualify of service is important for factor that environmental element influences in customer satisfaction as existing commercial transaction in this research hereupon. That is, wished to present quality strategy necessary to examine whether some quality factor of system quality and quality of service affects more customer satisfaction, and satisfy various customer's needs accordingly after ermine whether it are switching and some relation that search purchase alteration availability of market that is different from loyalty which recommend internet shopping mall to another person who is system quality factor and quality of service factor and customer satisfaction factor actively.

• The Korean Journal of Applied Statistics
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• v.35 no.2
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• pp.189-201
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• 2022

In this study, we propose factor augmentation to improve forecasting power of cryptocurrency return. We consider financial and economic variables as well as psychological aspect for possible factors. To be more specific, financial and economic factors are obtained by applying principal factor analysis. Psychological factor is summarized by news sentiment analysis. We also visualize such factors through impulse response analysis. In the modeling perspective, we consider ARIMAX as the classical model, and random forest and deep learning to accommodate nonlinear features. As a result, we show that factor augmentation reduces prediction error and the GRU performed the best amongst all models considered.