• Korean Journal of Microbiology
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• v.26 no.3
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• pp.262-269
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• 1988

In order to investigate the virulence of Y. enterocolitica isolated in Korea, all necessary experiments were done including several virulence determinating tests-autoagglutination test, calcium-dependency test, HeLa cell invasion test, Sereny test, crystal violet binding test, and electrophoresis for plasmid pattern. The obtained results are as follows: The virulent strains of Y. enterocolitica revealed positive reactions on autoagglutination test, cacium-dependency test, and drystal violet binding test, while the avirulent strains did not. A positive reaction was observed only at $37^{\circ}C$ implying that the expression of virulence is temperature-dependent. In Sereny test, the standard reference virulent strain (serotype 0:8) showed positive reactions while the virylent experimental strains (serotype 1:3, 0:9) revealed negative results, which indicates that the virulence of Y. enterocolitica in experimental animals varied according to their serotypes. Most of the virulent strains contained 36-38Mdal plasmids, but the avirulent strains did not. In addition, it was noted that autoagglutination, calcium-dependency, and crystal violet binding were related to the presence of plasmids.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.257-265
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• 2019

The purpose of the present study was to examine the causal relationship between aggression and mobile phone dependency among high school students and to test the mediating effect of self-esteem, and to draw out implications in order to encourage proper use of mobile phone. In this paper, we proposed a research model between aggression, self-esteem and mobile phone dependency. The present study analyzed the fourth, fifth, and sixth wave data from KCYPS 2010, using the structural equation modeling. The primary results were as follows. First, the effect of high school students' aggression on mobile phone dependency was not significant. Second, high school students' aggression had a significantly negative effect on self-esteem. Third, high school students' self-esteem had a significantly positive effect on mobile phone dependency. Fourth, high school students' self-esteem could be a significant mediator between aggression and mobile phone dependency. In conclusion, theoretical and practical suggestions were discussed in order to solve the problem of adolescents' mobile phone dependency.

• Human Ecology Research
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• v.62 no.3
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• pp.573-583
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• 2024

Smart devices have become an essential part of human life; however, excessive dependency on these devices has become a serious issue for both children and adults. In this study, a research model was developed which hypothesized that mothers' smartphone addiction influences children's media dependency, and that this effect is sequentially mediated by mothers' work-family strains and parental monitoring. To test this hypothesis, an analysis of data from the 13th Wave of Panel Study on Korean Children (PSKC), conducted in 2020, was performed. The data were collected from 726 children (359 boys, 367 girls) with an average age of 12.23 years (SD=.30). The analysis was conducted using SPSS 27.0 and Process MACRO Ver. 4.2. The results were as follows. Maternal smartphone addiction increased mothers' work-family strains, which in turn lowered the level of parental monitoring, which was associated with an increase in children's media dependency. Furthermore, mothers' smartphone addiction had a partial mediation effect on children's media dependency. In sum, this study revealed that the mothers' smartphone addiction increased children's media dependency, and this effect was sequentially mediated by an increase in mothers' work-family strains and a decrease in parental monitoring. This study verifies that mothers' smart device usage as well as their working environment has a significant effect on children's media dependency. Therefore, to increase parental monitoring of children's media usage, mothers' work-family strains need to be reduced.

• Journal of Korean Biological Nursing Science
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• v.18 no.4
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• pp.213-220
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• 2016

Purpose: The aim of this study was to identify the influence of knowledge, attitude and preventive health behavior of cancer on nicotine dependency in male college students who have a habit of smoking. Methods: In this study, a cross-sectional survey design was adopted for the 254 male college students who smoke in D and S city. The data was analyzed for descriptive statistics, t-test, Pearson's correlation coefficient and multiple regression analysis using the SPSS 20.0 program. Results: Knowledge about lung cancer (${\beta}=-.407$, p<.001), preventive health behaviors about cancer (${\beta}=-.223$, p<.001) and the smoking period ($5years{\leq}$) (${\beta}=.198$, p=.001) were identified as the factors influencing nicotine dependency of the subjects. The model explained 33% of variance in nicotine dependency (F=20.49, p<.001). Conclusion: The results suggest that anti-smoking educators should include the strategies to increase knowledge about lung cancer and preventive health behaviors of cancer, and to reduce the smoking period in their smoking cessation program.

• Women's Health Nursing
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• v.26 no.2
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• pp.191-199
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• 2020

Purpose: The purpose of this study was to investigate the effects of anxiety and smartphone dependency on sleep quality in pregnant women with preterm labor. Methods: The participants of this study were 111 pregnant women who were between 20 and 37 weeks of gestation and experienced preterm labor. The data were collected from October 1, 2018 to October 25, 2019. The collected data were analyzed using descriptive statistics (frequency, percentage, and standard deviation), as well as the t-test, Pearson correlation coefficients, and hierarchical multiple regression. Results: Significant negative correlations were found between anxiety and sleep quality and between smartphone dependency and sleep quality. Participants' history of preterm birth, pregnancy method, bowel movements, anxiety, and smartphone dependency significantly affected sleep quality, with an explanatory power of 18%. Conclusion: In order to improve the quality of sleep, which is an important health-related factor for pregnant women experiencing preterm labor, it will be necessary to identify a history of premature birth, pregnancies achieved using artificial reproductive technology, bowel problems, and smartphone dependency in advance and to provide nursing interventions accordingly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3C
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• pp.115-125
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• 2009

The preconsolidation pressure has been commonly determined by oedometer test. However, it can also be determined by insitu test, such as piezocone test with theoretical and(or) empirical correlations. Recently, Neural Network (NN) theory was applied and some models were proposed to estimate the preconsolidation pressure or OCR. It was already found that NN model can come over the site dependency and prediction accuracy is greatly improved when compared with present theoretical and empirical models. However, since the optimization process of synaptic weights of NN model is dependent on the initial synaptic weights, NN models which are trained with different initial weights can't avoid the variability on prediction result for new database even though they have same structure and use same transfer function. In this study, Committee Neural Network (CNN) model is proposed to improve the initial weight dependency of multi-layered neural network model on the prediction of preconsolidation pressure of soft clay from piezocone test result. Prediction results of CNN model are compared with those of conventional empirical and theoretical models and multi-layered neural network model, which has the optimized structure. It was found that even though the NN model has the optimized structure for given training data set, it still has the initial weight dependency, while the proposed CNN model can improve the initial weight dependency of the NN model and provide a consistent and precise inference result than existing NN models.

• Human Ecology Research
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• v.56 no.2
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• pp.145-156
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• 2018

This study investigates the effects of over-parenting behavior and peer-alienation on adolescents' school adjustment and explores the mediating effects of smartphone dependency on the above relations. The subjects were 1,882 first grade students in middle school selected from the 7th year data of the 2010 Korea Children and Youth Panel Survey (2010 KCYPS). Data were analyzed by descriptive statistics, Pearson's correlation, structural equational models, and Sobel test with SPSS 21.0 and Amos 18.0. The findings were as follows. First, there was no significant difference in the school adjustment according to gender. However, boys were higher in the perception of over-parenting behavior and peer-alienation, and girls were higher in smartphone dependency. Second, peer-alienation and smartphone dependency had negative impacts on the school adjustment. But over-parenting behavior had no significant effect on school adjustment. Third, smartphone dependency played a mediator role between over-parenting behavior and peer-alienation as well as the school adjustment. Fourth, there were no significant differences between boys and girls in the relations among over-parenting behavior, peer-alienation, smartphone dependency and school adjustment. But there was a slight difference in influence. The findings of this study suggest that interventions on how to use smartphone correctly are important for improving adolescents' school adjustment. In addition, gender differences in school adjustment should be considered for a better understanding.

• Journal of Korean Association for Spatial Structures
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• v.15 no.3
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• pp.103-110
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• 2015

Various hybrid dampers have been developed as increasing tall buildings in Korea. To minimize the installment space and cost, the new hybrid friction damper was developed using friction components. It is composed of two one-nodal rotary frictional components and a slotted bolted frictional connection. Because of these components, hybrid friction damper can be activated by building movements due to lateral forces such as a wind and earthquake. In this paper, displacement amplitude dependency tests were carried out to evaluate on the structural performance and the multi-slip mechanism of the hybrid damper. Test results show that the multi-slip mechanism is verified and friction coefficients are increasing as displacement amplitudes are increasing.

• Journal of Families and Better Life
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• v.21 no.4
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• pp.55-67
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• 2003

Nowadays, computer game dependency among adolescents, especially male adolescents, is emerging as a social problem. Therefore, treatment for computer game dependency has become positively necessary. This study aimed at investigating the effects of participation in sociodrama on the students suffering from computer game addiction. For this study, 380 male students in the 8th grade were asked to complete a questionnaire about themselves. After these data had been analyzed using SPSS, eight students were selected as the experimental group. The control group consisted of eight adolescents who were similar to the experimental group in the level of computer game dependency and in the psychological factors such as impulsiveness, depression, and the lack of self-control. The experimental group participated in twelve sociodrama sessions over 11 weeks, whereas the control group did not receive any treatment. The first follow-up test was conducted eleven weeks after the pretest, and the second follow-up test was done nine weeks after the first one. The results indicate that the sociodrama played an important role in alleviating the computer game addiction. At the same time, the participation in sociodrama brought positive changes in the psychological factors of the adolescents.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.644-655
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• 2008

Conventional hyperbolic model does not satisfactorily predict the overall stress-strain behaviors of various geomaterials. Tatsuoka and Shibuya(1992) suggest the generalized hyperbolic equation(GHE) considering strain dependency and calculated performance is in good agreement with precise triaxial compression test results of stress-strain relations over wide range of strains before peak stress condition in some cases, but GHE model also does not satisfactorily predict stress-strain relations as strain goes on state of peak stress in most cases. For improve a weak point of the GHE, in this study, modified form of generalized hyperbolic equation (MGHE model) is proposed which can predict highly nonlinear stress-strain behavior for various geomaterials from small strain to peak stress condition.