• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1364-1373
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• 2016

Ultra High Definition Television (UHDTV) has attracted much attention as one of next generation broadcasting services. For the commercialization of UHD broadcasting service, standardization groups including the DVB (Digital Video Broadcasting) and the ATSC (Advanced Television Systems Committee) have decided to adopt the Orthogonal Frequency Division Multiplexing (OFDM) for signal transmission. However, when the carrier frequency is not properly synchronized at the receiver, inter-symbol interference (ISI) and inter-carrier interference (ICI) may occur. In order to avoid performance degradation resulting from ISI or ICI, receivers should synchronize the carrier frequency by using preambles and pilot symbols. However, there only few published literature dealing with the frequency offset estimation methods regarding the next generation terrestrial broadcasting. In this respect, this paper proposes a method to estimate timing and fractional frequency offset for the ATSC 3.0 system by using a preamble bootstrap symbol. The proposed detector can detect the fractional frequency offset by adding a complex conjugate product on the conventional estimator where only timing offset can be estimated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.340-348
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• 2020

This study was conducted to find the mediating effect of self-leadership in the relationship between academic self-efficacy and college-life satisfaction of Chinese students majoring in beauty. Surveys were answered by 400 Chinese students from July to August 2019 and analyzed as follows. We used the SPSS22.0 program and Process macro for SPSS to analyze the frequency, descriptive statistics, correlation analysis, and bootstrap method. The results of the analysis showed a positive correlation among the college-life satisfaction, self-leadership, and academic self-efficacy of Chinese students, and self-leadership acted as a partially mediating variable between academic self-efficacy and college-life satisfaction. Therefore, it was found that a higher college-life satisfaction and self-leadership resulted in a higher academic self-efficacy. Based on these results, in order to alleviate the problems of college life maladjustment and low learning efficiency of Chinese students majoring in beauty, the development of self-leadership education programs is becoming more important. This must be emphasized in the Edu-Tech era due to the need for customized education programs for international students amidst the COVID-19 pandemic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.618-627
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• 2017

Recently, the number of cases of child abuse has been increasing and, consequently, the social interest in this issue is increasing. The purpose of this study is to examine the relationship between child abuse, rejection sensitivity and emotional regulation and to identify the mediating effects of rejection sensitivity in the relationship between child abuse and emotional regulation. For this purpose, a survey on child abuse, rejection sensitivity and emotional regulation was administered to 217 elementary school students in the fourth, fifth and sixth grades, who had been reported as victims of child abuse or managed as suspected child abuse victims in the Seoul, Gyeonggi, Gangwon, Chungcheong, and Gyeongsang regions. The data was analyzed using structural equation modelling and bootstrapping. The findings showed that child abuse was significantly negatively correlated with emotional regulation, but positively correlated with rejection sensitivity. Emotional regulation was significantly negatively correlated with rejection sensitivity. Second, the structural equation analysis also revealed that rejection sensitivity fully mediated the relationship between child abuse and emotional regulation. This means that child abuse has an indirect effect on emotional regulation through rejection sensitivity. Therefore, when counseling abused children with emotional regulation problems, it is important for the counselors to include interventions designed to lower their rejection sensitivity.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.15-21
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• 2017

Our current study aimed to verify the mediating effect of growth mindset and grit in the relationship between human rights victimization and self-esteem. The survey was conducted on 233 college students. Reliability analysis, correlation analysis, and Macro Process were performed, and bootstrap method was used to verify the mediating effect of growth mindset and grit. The results were as follows. First, human right victimization were significantly and negatively correlated with self-esteem, growth mindset, and grit while self-esteem were significantly and positively correlated with growth mindset, and grit. Second, as a result of path analysis, the human rights victimization had a significant negative impact on self-esteem, growth mindset and grit. On the other hand, growth mindset and grit had a significant positive effect on self-esteem. Third, growth mindset and grit had a mediating effect in the relationship between human right victimization and self-esteem. This implied that self-esteem of college students can be increased by increasing their growth mindset and grit. Future research is needed to clarify the role of human rights research and growth mindset and self - esteem in college students.

• Journal of Industrial Convergence
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• v.18 no.1
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• pp.87-96
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• 2020

The purpose of this study was to examine the dual mediating effects of growth mindset and hope between body image and successful aging of the elderly. For this purpose, we surveyed 422 elderly people in D and S city of Chungcheongnam-do, and D metropolitan city. Collected data were analysed using SPSS 25.0 and PROCESS macro 3.4 program. Frequency analysis, reliability analysis and dual mediating effect analysis by using bootstrap were performed. The results of the study are as follows. First, as a result of correlation analysis there was a statistically significant positive correlation between variables. Second, as a result of path analysis, body image had a positive effect on growth mindset and hope, growth mindset had a positive effect on hope and successful aging, and hope also had a significant effect on successful aging. Third, as a result of dual mediation effect analysis, growth mindset and hope mediated in the relationship between body image and successful aging. This study provided new models and basic data by using body image, growth mindset and hope for successful aging of the elderly.

• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.628-633
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• 2006

ITS DNA sequences from five individuals, representative of five groups designated according to the degree of leaf teeth and lobes from simple to palmate compound leaf in the Viola albida complex, established and further analysed in order to solve the taxonomic difficulty. A total 702 bp was sequenced at the 5.8S ribosomal DNA and internal transcribed spacer 1 and 2. The 5.8S coding region is 163 bp, and has no sequence variations. The ITS1 and ITS2 noncoding regions have a little bit sequence variations, and those were further analysed by the methods of the analysis of variance (ANOVA), the analysis of sequence divergence and the phylogenetic analysis. The result of ANOVA showed no significant differences among individuals investigated. The analysis of sequence divergence with Kimura 2-parameter distance revealed that in-groups showed much less than 0.05 in absolute value among individuals, while two out groups more than 0.05, V. grypoceras and V. orientalis. This result appeared that the sequence divergence among in-groups was not yet occurred in the species level but situated at somewhere below the species level. In the phylogenetic analysis, two outgroups formed the basal clades in order. Five individuals in-groups formed a clade. The clade was, however, not very robust as around 50% in bootstrap value, suggesting that this result was not meaningful in the phylogenetic point of views.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.203-215
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• 2013

This study calculated meta Malmquist indices and their bootstraped estimates and then decomposed them into technical efficiency change(TEC), technology change(TC), pure technology catch up(PTCU), frontoer catch up(FCU), using annual data set of general hospitals from year 2007 to 2011 collected by Korean Hospital Association and then analyzed productivity change and technology gap of Korean general hospitals. The results and implications were as follows below. First, public general hospitals showed higher meta technical efficiencies than private general hospitals while exhibited lower technology gap ratio which meant a few large private general hospitals led the whole general hospitals. Second, group productivity of private general hospitals increased larger than public general hospitals due to the differences of PTCU rather than FCU. But, there was no statistically significant differences for technical efficiency, productivity change, technology gap. Thus, public general hospitals played the same role as the private general hospitals in terms of the number of patients treated. But, considering financial hardships of public general hospitals, public hospitals needed to share and learn medical and managerial skills of the best practice of private general hospitals.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.9
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• pp.375-384
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• 2021

Deep learning techniques have been proven to have high performance in image processing and are applied in various fields. The most widely used methods for validating a deep learning model include a holdout verification method, a k-fold cross verification method, and a bootstrap method. These legacy methods consider the balance of the ratio between classes in the process of dividing the data set, but do not consider the ratio of various features that exist within the same class. If these features are not considered, verification results may be biased toward some features. Therefore, we propose a deep learning model validation method based on data feature coverage for image classification by improving the legacy methods. The proposed technique proposes a data feature coverage that can be measured numerically how much the training data set for training and validation of the deep learning model and the evaluation data set reflects the features of the entire data set. In this method, the data set can be divided by ensuring coverage to include all features of the entire data set, and the evaluation result of the model can be analyzed in units of feature clusters. As a result, by providing feature cluster information for the evaluation result of the trained model, feature information of data that affects the trained model can be provided.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.140-154
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• 2021

This study examines the structural relationship between parents' positive and negative parenting attitudes, life satisfaction, and academic helplessness. To this end, 2,595 middle school students (1,405 boys and 1,185 girls) were used among the KCYPS 2018 panel materials. The model was validated using a structural equation model, and the verification of the mediated effects of life satisfaction was significant with bootstraps. The results of the study are as follows. First, the positive and negative parenting attitudes of parents have a significant impact on life satisfaction. These results can be interpreted as having an impact on the lives of adolescent children, depending on their parenting attitudes. Second, the positive and negative parenting attitudes of parents have a significant impact on academic helplessness. These results can be interpreted as having an effect on the academic performance of adolescent children depending on their parenting attitudes. Third, satisfaction in life has a significant adverse effect on academic helplessness. These results can be interpreted as having a positive impact on studies according to the satisfaction level of youth's life, and having a negative impact on studies if life satisfaction is high and life satisfaction is low. Fourth, the satisfaction of life is mediated between parents' positive and negative parenting attitudes and academic helplessness. Through this study, it is meaningful in that it allows parents to understand the process of life satisfaction affecting their academic helplessness according to their parenting attitudes.

• Environmental and Resource Economics Review
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• v.28 no.2
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• pp.277-306
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• 2019

Mackerel is one of the most widely consumed aquatic products in Korea. Concerns about the depletion of stocks have also arisen as the catch has decreased. The primary purpose of this study is to estimate the mackerel stock and derive the optimal level of catch in Korea. We apply a generalized maximum entropy econometric method to estimate the mackerel growth function, which does not require the steady state assumption. We incorporate a bootstrapping approach to derive the significance levels of parameter estimates. We found that the average ratio of catch to the estimated total stock was less than 30% before the 1990s but exceeded 40% in the 1990s. After 2000, it dropped back to about 36%. This finding indicates that mackerel may have been over-fished in the 1990s, but the government regulations introduced in the 2000s alleviated over-fishing problems. Nevertheless, our dynamic optimization analysis suggests that the total allowable catch may need to be carefully controlled to achieve socially optimal management of resources.