• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.11
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• pp.503-507
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• 2005

Both ratio error and phase angle error in voltage transformer(VT) depend on values of VT burden used. Thus, precise measurement of burden is very important for the evaluation of VT. A method of evaluation for VT burden has been developed by employing the portable decade resistor, with AC-DC resistance difference less than 10-3. The burden value(value and power factor) can be obtained by conductance and susceptance, obtained by measuring the change of ratio error and phase angle error caused by the resistance change of decade resistor. The burden value and power factor obtained by the method are consistent with those obtained using power analyzer within corresponding uncertainties.

• Journal of Agricultural Extension & Community Development
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• v.16 no.3
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• pp.557-586
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• 2009

The objective is to find the classification criteria between urban and rural, and to classify the urban and rural area all the country in Korea. For the research objectives, reviews of related literature and statistical yearbooks were used for finding criteria and analysing data. Through reviewing the literature, some indicators were selected in views of rurality and urbanity, and gathered the data from statistical yearbooks. And factor analysis was used to find first and second factor for classifying region. Six factors as a city surrounding(36%), non-farmer household population ratio(28.1%), cultivated acreage(12.48%), agricultural production surrounding (12.40%), the farm family number change(5.58%) and household number rise and fall(5.54%) were finding. And rurality factors were cultivated acreage, agricultural production surrounding, the farm family number change and household number rise and fall, and urbanity factors were city surrounding and non-farmer household population ratio. Based on the first and second factor loaded amount, four type regional classification was followed.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.981-996
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• 2003

Bayesian inference is considered for switching mean models with the ARMA errors. We use noninformative improper priors or uniform priors. The fractional Bayes factor of O'Hagan (1995) is used as the Bayesian tool for detecting the existence of a single change or multiple changes and the usual Bayes factor is used for identifying the orders of the ARMA error. Once the model is fully identified, the Gibbs sampler with the Metropolis-Hastings subchains is constructed to estimate parameters. Finally, we perform a simulation study to support theoretical results.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.433-438
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• 2000

The purpose of this study is to examine the resistance of water-permeable concretes to freezing and thawing action. The water-permeable concretes with cement-aggregate ratio of 1:5.5(by weight) and two kinds of admixture content [SP : superplasticizer(0, 1.0%), HPAE : high performance air entraining agent(0.5, 1%)] used OPC(ordinary portland cement) as binder were prepared, and then tested for relative dynamic modulus of elasiticity, mass change, length change and durablity factor. It's been concluded from the test results that the superior relative dynamic modulus of elasiticity and durability factor of water-permeable concretes were obtained at superplaciticizer 1.0% after 300 cycles. The water-permeable concretes used superplasiticizer 1.0% having relative durability factor of 88% after 300 cycles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.264-269
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• 2009

Marginal Loss Factor(MLF) is represented as the sensitivity of transmission loss, which is computed from the change of the generation at slack bus by the change of the load at the arbitrary bus. The MLF dependent on the selection of slack bus is one of the key factors affecting nodal pricing, Genco's profits, social welfare(SW) and Nash Equilibrium in a competitive electricity market. This paper addresses the methodology of slack bus selection by using Cournot model of Cost Based Pool market. Numerical results from sample cases show that the slack bus of MLF of the highest average is beneficial from the view points of SW.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.19-26
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• 2006

In this study, psychological assessment was carried out to investigate the driver's psychological characteristics by the change of the headlight. The participants were 20 men and 20 women in their 20s and thirty-two different conditions in combinations of waveform of light, voltage, and alteration time were used. The questionnaire for the assessment was evaluated by 8 subjective item and 5-point SD criteria of 19 pair's adjective. The results were as follows : 1. The assessment results from SD method indicated 4 factors by factor analysis, and it was shown that A waveform had significances in a sense of security and impetus and B waveform had a significance in a sense of security. The levels of the limitations for the voltage change were 12[V] in the factor of a sense of security and 11[V] in the factor of a sense of impetus for A waveform, 12.6[V] in the factor of a sense of security for B waveform. 2. The results of the subjective assessment showed that the limitation of A waveform's brightness change was 12[V]. Moreover, the limitations of voltage changes were 12.67[V] for B waveform brightness change, 12.12[V] for discomfort, 12.71[V] for darkness. And the limitation of C waveform's brightness change was 12[V].

• Journal of Technology Innovation
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• v.15 no.2
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• pp.1-24
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• 2007

In this study, we estimated a CES production function for the Korean economy. We have found in the empirical results that the elasticity of the factor substitution is less than one and that the Korean economy exhibits labor-saving technological progress. In addition, we obtained the regression coefficient of R&D investment on technological change, i.e., the elasticity of R&D investment with respect to the technological change was 0.26% point. It implies that if R&D stock increases by 1%, labor efficiency increases 0.26% point through technological progress which is Hicksian non-neutral. It confirms that innovation-based growth strategy by increasing R&D investment would be effective on the one hand. Some policy consideration on the other might be needed for an increase in employment which is offset by technological progress.

• Korean Journal of Health Education and Promotion
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• v.20 no.3
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• pp.255-267
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• 2003

The purpose of this study is to analyze the affecting factors on self-efficacy of walking exercise. The subjects were 413 working men. Whose data and material were collected through an organized questionnaire from October, 1999 to May 2000. The major results of this were as follows； 1. 61.1％ of the subjects' major affecting factor was deep sleep, 65.0％ of the subjects' majo affecting facto was regular physical screening, 51.1％ of the subjects' regular exercise, 18.7％ of the subjects' walking exercise. 2. stages of change related to walking exercise of the subjects were as follows, 15.8％ of the subjects were in the precontemplation stage, 51.1％ of the subjects were in the precontemplation stage. 3. The average self-efficacy concerning walking exercise was 3.16 points. 4. With stepwise multiple regression, the most significant factor on self-efficacy related to walking exercise in stages of change was the preparation stage. According to the results of this study, a concrete practice program is needed to promote self-efficacy related walking exercise.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.262-264
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• 2002

This paper describes the proposed application of MLF(marginal loss factor) in korean wholesale electricity market in accordance with the proposal of wholesale market design, and presents the analysis result of the impact of MLF change on the electric power trading when the reference node for the MLF calculation is changed.

• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.367-372
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• 2006

Since 1990's, many enterprises have constructed Integration Information System. Especially, they want to become an advanced company use ERP package. Already, ERP system come to high level which is stabilized and support independent business process of many industry sectors. Therefore, important success factors for ERP project are change management and organization activation. Although most companies had previous good plans, but those are not satisfied. Because of failed to change management and discontinued next activity for promotion. This paper studied success factors of project team and plan for organization activation. Also, it proposed next study subject about investigate the role of the member of task force team as a factor that makes the ERP system a success. The results of this study can be used for a successful construction of the ERP system as a solution about internal problems of Project team.