• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.159-169
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• 2009

In this study, static loading tests and numerical analyses of the composite beam strengthened by multi-stepwise thermal prestressing method were carried out to evaluate the prestressing effect of the thermal prestressing prestress and the sectional effect of the installed cover-plate on the increase in the load-carrying capacity of composit beam. From this study, the strengthening method using multi-stepwise thermal prestressing method (TPSM) can be applied to reduce the deflection of the composite beam as well as to strengthening the composite beam by inducing the prestress in case of the occurrence in the large deflection by the insufficiency of the section properties of the composite beam. because of the expectation of the increase in the yield load and the sectional properties of the composite beam.

• Journal of the Korean Data and Information Science Society
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• v.19 no.3
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• pp.789-800
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• 2008

Current credit evaluation models based on financial data make use of smoothing estimated default ratios which are transformed from each financial variable. In this work, some problems of the credit evaluation models developed by financial experts are discussed and we propose improved credit evaluation models based on the stepwise variable selection method and Box-Cox transformed data whose distribution is much skewed to the right. After comparing goodness-of-fit tests of these models, the validation of the credit evaluation models using statistical methods such as the stepwise variable selection method and Box-Cox transformation function is explained.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.3
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• pp.167-181
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• 2001

A stepwise driving method was used for reducing the AC power consumption in a TFT-LCD. The AC power takes the largest portion of the total power consumption of a TFT-LCD. Experimental results confirmed that the AC power saving efficiency reached up to 75% when a 5-stepwise driving with each step time of $2\mu$ sec was applied to a 14.1 inch-diagonal XGA TFT-LCD. The second largest component of power consumption called the DC power comes from the quiescent currents in Op-amps. A simple and efficient architecture was proposed in this work to reduce this DC power consumption: Half of the Op-amps have the 5V-supplies, and the rest half have the 10V-supplies, and two Op-amps are shared by adjacent two channels. Measurements of test circuits showed that this simple method could reduce over 40% of the DC power consumption..

• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.51-56
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• 1999

Finite element method was utilized to analyze crack tip stress and displacement field under drying stress case as stepwise loading. Opening mode of single-edge-notched model was employed and analyzed by linear elastic fracture mechanics of plane stress case. The drying stresses were applied as stepwise loads at the boundary elements of the model with 10 steps of time serial. The stress intensity factor($K_I$) for opening mode reached to its maximum just prior to the stress reversal. The $K_I$ from the displacement fields revealed 1.7 times higher than those from stress fields. By comparing the two sets of $K_I$ from displacement and stress fields, single parameter $K_I$ showed its validity to characterize displacement fields around the crack tip front while stress field could not be characterized due to large variations between two sets of data.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.4
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• pp.277-281
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• 2006

Cyber counseling, one of the most compatible type of consultation for the information society, enables people to reveal their mental agonies and private problems anonymously, since it does not require face-to-face interview between a counsellor and a client. However, there are few cyber counseling centers which provide high quality and trustworthy service, although the number of cyber counseling center has highly increased. Therefore, this paper is intended to enable an appropriate consultation for each client by analyzing client propensity using Bayesian variable selection. Bayesian variable selection is superior to stepwise regression analysis method in finding out a regression model. Stepwise regression analysis method, which has been generally used to analyze individual propensity in linear regression model, is not efficient since it is hard to select a proper model for its own defects. In this paper, based on the case database of current cyber counseling centers in the web, we will analyze clients' propensities using Bayesian variable selection to enable individually target counseling and to activate cyber counseling programs.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.238-241
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• 2006

The needs for strengthening and rehabilitation of the concrete bridges are a growing concern in many countries and has been emphasized in various researches and papers. Traditional external post-tensioning method using either steel bars or tendons is commonly used as a strengthening method. However, the method has some disadvantages such as stress concentration at the anchorages. Multi-stepwise thermal prestressing method is a newly proposed method for strengthening and rehabilitation of concrete girder bridges. Founded on a simple concept of thermal expansion and contraction of steel, the method is a hybrid method of external post-tensioning and steel plate bonding, combining the merits of two methods. In this paper, basic concepts on strengthening and rehabilitation of concrete girder are presented and an illustrative experiment is introduced.

• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.133-147
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• 2001

Recently developing method of age determination using stepwise dissolution technique to expand the applicability of absolute age determination significantly is evaluated whether it is applicable to the Korean samples. The materials selected for the study are uranium-bearing black slates from Changni Formation of Ogcheon metamorphic belt, tourmaline separated from Naedeongni granite of Yeongnam massif, garnet and ilmenite separated from ilmenite-bearing anorthositic rock of Yeongnam massif, scheelites from Ogbang mine, and magnetite separated from Gyemyeongsan Formation of Ogcheon metamorphic belt. For the stepwise dissolution, various acid steps with different normalities and different durations were applied to leach the samples. The leachate from each step was analyzed to determine the Pb isotopic composition and concentrations of Pb and U using thermal ionization mass spectrometer. The black slates from the Changni Formation and the tourmaline from the Naedeongni granite reveal significant variation of Pb isotopic composition, which reveals the potential of such stepwise dissolution technique as a dating method. The behaviors of uranium and lead during the each stage of step leaching are different, which seem to reflect the differences in positions within the crystal lattices depending upon mineral species.

• Journal of Korean Academy of Nursing
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• v.33 no.5
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• pp.625-632
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• 2003

Purpose: The purpose of this study was to assess the importance and sensitivity to nursing interventions of four nursing sensitive nursing outcomes selected from the Nursing Outcomes Classification (NOC). Outcomes for this study were 'Knowledge: Diet', 'Knowledge: Disease Process', 'Knowledge: Energy Conservation', and 'Knowledge: Health Behaviors'. Method: Data were collected from 183 nurses working in 2 university hospitals. Fehring method was used to estimate outcome and indicators' content and sensitivity validity. Multiple and stepwise regression were used to evaluate relationships between each outcome and its indicators. Result: Results confirmed the importance and nursing sensitivity of outcomes and their indicators. Key indicators of each outcomes were found by multiple regression. 'Knowledge: Diet' was suggested for adding new indicators because the variance explained by indicators was relatively low. Not all of the indicators selected for stepwise regression model were rated for highly in Fehring method. The R² statistics of the stepwise regression models were between 18 and 63% in importance by selected indicators and between 34 and 68% in contribution by selected indicators. Conclusion: This study refined what outcomes and indicators will be useful in clinical practice. Further research will be required for the revision of outcome and indicators of NOC. However, this study refined what outcomes and indicators will be useful in clinical practice.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.31-39
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• 2015

This paper deals with a method for estimating variance components on the basis of projections under the assumption of random effects model. It discusses how to use projections for getting sums of squares to estimate variance components. The use of projections makes the vector subspace generated by the model matrix to be decomposed into subspaces that are orthogonal each other. To partition the vector space by the model matrix stepwise procedure is used. It is shown that the suggested method is useful for obtaining Type I sum of squares requisite for the ANOVA method.

• Asia-Pacific Journal of Atmospheric Sciences
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• v.54 no.4
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• pp.611-622
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• 2018

Observed climate data are processed under the assumption that their time series are stationary, as in multi-step temperature and precipitation prediction, which usually leads to low prediction accuracy. If a climate system model is based on a single prediction model, the prediction results contain significant uncertainty. In order to overcome this drawback, this study uses a method that integrates ensemble prediction and a stepwise regression model based on a mean-valued generation function. In addition, it utilizes empirical mode decomposition (EMD), which is a new method of handling time series. First, a non-stationary time series is decomposed into a series of intrinsic mode functions (IMFs), which are stationary and multi-scale. Then, a different prediction model is constructed for each component of the IMF using numerical ensemble prediction combined with stepwise regression analysis. Finally, the results are fit to a linear regression model, and a short-term climate prediction system is established using the Visual Studio development platform. The model is validated using temperature data from February 1957 to 2005 from 88 weather stations in Guangxi, China. The results show that compared to single-model prediction methods, the EMD and ensemble prediction model is more effective for forecasting climate change and abrupt climate shifts when using historical data for multi-step prediction.