• Journal of Digital Convergence
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• v.18 no.6
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• pp.297-309
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• 2020

This study focuses on the application of the data mining technique logistic regression analysis and decision tree analysis to the domestic public database called Korean Children Youth Panel Survey (KCYPS) to derive a series of important factors affecting the enhancement of life satisfaction of domestic youth. As a result, the general impact factors on life satisfaction for each grade were derived from logistic regression. Using decision tree analysis, we came to conclusions that those factors such as depression, overall grade satisfaction, household economic level, and school adaptation play crucial roles in affecting high school adolesscents' life satisfaction.

• Journal of Korea Multimedia Society
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• v.10 no.10
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• pp.1271-1283
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• 2007

To detect defect of FPD(flat panel displays) is very difficult due to uneven illumination on FPD panel image. This paper presents a method to detect various types of defects using the approximated image of the uneven illumination by B-spline. To construct a approximated surface, corresponding to uneven illumination background intensity, while reducing random noises and small defect signal, only the lowest smooth subband is used by wavelet decomposition, resulting in reducing the computation time of taking B-spline approximation and enhancing detection accuracy. The approximated image in lowest LL subband is expanded as the same size as original one by wavelet reconstruction, and the difference between original image and reconstructed one becomes a flat image of compensating the uneven illumination background. A simple binary thresholding is then used to separate the defective regions from the subtracted image. Finally, blob analysis as post-processing is carried out to get rid of false defects. For applying in-line system, the wavelet transform by lifting based fast algorithm is implemented to deal with a huge size data such as film and the processing time is highly reduced.

• The Korean Journal of Financial Management
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• v.27 no.2
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• pp.63-84
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• 2010

We investigate whether FX hedging materially increases firm value by testing the valuation effect of Foreign Exchange Risk Insurance in Korea, using our sample of 84 listed firms with 617 observations between 2000 and 2008, Employing Tobin's Q as a proxy of firm value and foreign exchange risk insurance as a proxy of hedging instrument, we find a positive relation between firm value and the use of foreign exchange risk insurance. The hedging premium is statistically significant and is on average 7.4% of sample firm value. We also find our empirical results consistent with the preceding evidence that firm uses the hedging instrument in order to alleviate economic frictions and then hedging causes an increase in firm value.

• Environmental and Resource Economics Review
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• v.26 no.1
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• pp.37-56
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• 2017

This study analyzed the mutual causal relationship between energy consumption, production, and export for manufacturing industry in Korea. The Korean manufacturing industry was divided into nine industries and panel data was constructed from 1991 to 2013. The panel Granger causality test method developed by Demitrescu and Hurlin (2012) was used along with the Vector Error Correction Model. This analysis showed that there was Granger Causality from production to energy consumption, from exports to energy consumption. However, Granger Causality was not established in the opposite direction. Therefore, this result supports the conservation hypothesis of Qzturk (2010) that energy-saving policies in the manufacturing sector can be implemented without adverse effects on production or exports in short-run. There is a long-run cointegrating relationship between production, energy consumption, exports, labor, and capital in the Korean manufacturing sector. Furthermore, the energy consumption contributes to the increasing of production in long-run equilibrium relationship.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.2
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• pp.149-166
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• 2013

The purpose of this study is to analyze the regional disparity and its determinants of $CO_2$ emission from the residential energy consumption in China. This study examines factors that affect the $CO_2$ emission per capita using the panel model. The panel model was set by a balanced panel data for 30 provinces and for the period of 2006~2011. $CO_2$ emission per capita is used as the dependent variable and characteristics of the household and regional physical environmental factors are selected as the explanatory variables. The important findings can be summarized as follows. $CO_2$ emission per capita is influenced by the ratio of the graduate students, household size, the ratio of the old-aged, female economic participation rate. High residential density is negatively affected on $CO_2$ emission. The findings suggest that the effect of policies reducing $CO_2$ emission per capita may vary by characteristics of the household, energy sources and regional climate. The results of this empirical study give some implications to reduce the residential energy consumption in the era of climate change.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.711-720
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• 2010

This study is aimed to compare choices on interaction problems, and to consider the reason of the choices. It was expected that the interaction problems are influenced from national culture, age, gender and so on. The first interaction problem in this study is default answer button when user operates to delete all messages on SMS in-box. Second one is action when pop-p window warning dangerousness of install showed on web browsing. The third one is type(analog/digital) and information expression of control panel on soup maker. 639 Korean data and 784 data from China, Japan and the Netherlands are analyzed through cross-tabulation and chi-square test. In the results, many Japanese choose 'No' answer at SMS delete problem, while many Dutch choose 'Yes'. The result suggests that uncertainty avoidance effect on interaction problems. On warning pop-up, Younger generation and men choose actively 'install' than older one and women. On type of control panel, Dutch subjects preferred analog type than other countries' subjects. On expression of control panel, older generation and individualistic subjects relatively preferred text style than other style.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.340-352
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• 2015

The purposes of this study is to analyze gender difference in predictors of mobile phone dependency in youth. The analysis is performed with third-year panel survey data of middle school 1st grade students from Korean Child-Youth Panel Survey. The results are as follows. First, the female students' mobile phone dependency is more serious than the male students' mobile phone dependency. Second, while the identified male gender predictors are aggression, parental abuse, aprosexia, study activity and social withdrawal, the identified female gender predictors are depression, aprosexia, aggression, study activity and social withdrawal. Based on these results, theoretical and practical implications in planning of prevention or intervention of mobile phone dependency are proposed.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1147-1154
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• 2016

Impact of Korea train express (KTX) on the regional economy in Korea has been studied by many researchers. Current research is limited in the lack of quantitative research using a statistical model to study the effect of KTX on regional economy. This paper analyses the influence of KTX to the household final consumption expenditure, which is one of important regional economic index, using spatial panel regression model. The spatial structure is introduced through spatial autocorrelation matrix using adjacency of KTX connection. The result shows a significant effect of Korea train express on the regional economy.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.6
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• pp.31-38
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• 2009

To improve the image quality and lower the power consumption of the mobile applications, it is the one of the best candidate to control the backlight unit of the LCD module with ambient light. Ambient light sensor and readout circuit were integrated in LCD panel for the mobile applications, and we designed them with LTPS TFT. We proposed noble start-up correction in order to correct the variation of the photo sensors in each panel. We used time-to-digital method for converting photo current to digital data. To effectively merge time-to-digital method with start-up correction, we proposed noble dual slope correction method. The entire readout circuit was designed and estimated with LTPS TFT process. The readout circuit has very simple and stable structure and timing, so it is suitable for LTPS TFT process. The readout circuit can correct the variation of the photo sensors without an additional equipment, and it outputs the 4-levels digital data per decade for input luminance that has a dynamic range of 60dB. The readout rate is 100 times/sec, and the linearity error for digital conversion is less than 18%.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.55-65
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• 2015

An increase in patients' medical expenses for their injury. accident and intoxication is a major challenge to improve the sustain-ability of a national health security system, and increasing medical expenses need be suppressed through improving relevant systems and/or efficiently operating and managing the health insurance. At this juncture, in Korea which has a high rate of injury incidence and mortality, it is necessary to estimate social and/or economic costs for injuries with a focus on their social effects. This research has examined the results of a Korea medical panel investigation conducted in 2008, which largely surveyed of the actual conditions of outpatients' medical use for their injury, accident and/or intoxication and investigated relevant medical expenses, with a view to estimating the directly incurred costs when the patients use medical services and the production loss costs caused by an production decline and others, so that social and/or economic costs for injuries may be ultimately aggregated.