• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.422-427
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• 2003

The purpose of this study analyzes the effects of M＆A between conglomerate and non-conglomerate corporational with 57 samples of firms during the period from 1990 to 1997 right before IMF. financial crisis. These models employed to measure effects of M＆A in this paper are both market model and market adjusted return model using test of t-statistics. Results of this article show that negative excess returns are observed for non-conglomerate mergers and positive excess gains are exhibited for conglomerate mergers. This implies that conglomerate mergers are more effective than firm specialization in terms of merger effects.

• The Plant Pathology Journal
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• v.32 no.2
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• pp.145-156
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• 2016

Fusarium graminearum Schwabe causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss of wheat and other cereal crops. Twelve isolates of F. graminearum were collected from naturally infected spikes of wheat from Assiut Egypt. These isolates were compared using SRAP. The results indicated distinct genetic groups exist within F. graminearum, and demonstrated that these groups have different biological properties, especially with respect to their pathogenicity on wheat. There were biologically significant differences between the groups; with group (B) isolates being more aggressive towards wheat than groups (A) and (C). Furthermore, Trichoderma harzianum (Rifai) and Bacillus subtilis (Ehrenberg) which isolated from wheat kernels were screened for antagonistic activity against F. graminearum. They significantly reduced the growth of F. graminearum colonies in culture. In order to gain insight into biological control effect in situ, highly antagonistic isolates of T. harzianum and B. subtilis were selected, based on their in vitro effectiveness, for greenhouse test. It was revealed that T. harzianum and B. subtilis significantly reduced FHB severity. The obtained results indicated that T. harzianum and B. subtilis are very effective biocontrol agents that offer potential benefit in FHB and should be harnessed for further biocontrol applications. The accurate analysis of genetic variation and studies of population structures have significant implications for understanding the genetic traits and disease control programs in wheat. This is the first known report of the distribution and genetic variation of F. graminearum on wheat spikes in Assiut Egypt.

• Korean Parent-Child Health Journal
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• v.15 no.2
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• pp.51-59
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• 2012

Purpose: The purpose of this study was to identify factors influencing health promoting behavior of school-aged children on community child center. Methods: Participant were 207 elementary school student located in Mokpo. For data analysis descriptive statistics, t-test, ANOVA pearson correlation coefficients and stepwise multiple regression were used with SPSS/WIN ver 18.0 program. Results: The mean score for health promoting behavior was below the lower point at $3.39{\pm}0.61$. There were significant differences in health promoting behavior according to gender (t=9.41, p=.002), father's job (F=2.28, p=.048), perceived health status (F=5.70, p=.001), There were significant correlations between health promoting behavior and self-esteem (r=.655, p=.001), self-efficacy (r=.530, p=.001). The explanatory power of these variables accounted for 47.1% of health promoting behavior. The most significant variable was self-esteem (t=7.60, p=.001) and explained 42.8%. Conclusion: The finding indicate that self-esteem of children on community child center are important variables for health promoting behavior. This result suggests that interventions focusing on self-esteem, on enhance health promoting behavior.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.591-599
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• 2016

This study has examined and compared the Organizational performance of the Diversity management focusing on Japanese Companies Employing the Elderly and persons with disabilities. To achieve the research objectives, I performed T-test. The total number of the date used in this study is 1,704. The findings from the t-tests are: the Organizational Productivity and Organizational security of companies employing the Elderly and persons with disabilities are better than those of companies managing Gender Diversity or not carrying out at all.

• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.675-691
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• 2017

Jets in cross flow are of fundamental industrial importance and play an important role in validating turbulence models. Two jet configurations related to thermal fatigue phenomena are investigated: ${\bullet}$ T-junction of circular tubes where a heated jet discharges into a cold main flow and ${\bullet}$ Rectangular jet marked by a scalar discharging into a main flow in a rectangular channel. The T-junction configuration is a classical test case for thermal fatigue phenomena. The Vattenfall T-junction experiment was already subject of an OECD/NEA benchmark. A LES modelling and calculation strategy is developed and validated on this data. The rectangular-jet configuration is important for basic physical understanding and modelling and has been analyzed experimentally at CEA. The experimental work was focused on turbulent mixing between a slightly heated rectangular jet which is injected perpendicularly into the cold main flow of a rectangular channel. These experiments are analyzed for the first time with LES. The overall results show a good agreement between the experimental data and the CFD calculation. Mean values of velocity and temperature are well captured by both RANS calculation and LES. The range of critical frequencies and their amplitudes, however, are only captured by LES.

• The Mathematical Education
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• v.49 no.3
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• pp.299-311
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• 2010

The purpose of this study was to examine the effects of abstraction offer of basic concept principle and feedback of self-efficacy attributional and mathematical study ability of math underachievers in high school based on the attribution theory and self-efficacy theory. The hypothesis were posed as below : Hypothesis 1: The experimental group that takes the abstraction offer of concept principle and attributional feedback training would be better at most self-efficacy than the control group that doesn't. Hypothesis 2: The experimental group that takes the abstraction offer of concept principle and attributional feedback training would have better math achievement than the control group that doesn't. They were divided into an experimental group and a control group, and the attribution disposition, self-efficacy and academic achievement of the children were measured by pretest and posttest. For data analysis, SPSS/PC+ program was employed and t-test was conducted. The main findings of this study were as below : First, the abstraction offer of concept principle and attributional feedback training was effective for enhancing the math self-efficacy in high school underachievers. Second, the abstraction offer of concept principle and attributional feedback training was effective for increasing the math achievement in high school underachievers.

• Journal of Cancer Prevention
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• v.21 no.3
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• pp.135-143
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• 2016

Background: Fraxetin (7,8-dihydroxy-6-methoxy coumarin), a coumarin derivative, has been reported to possess antioxidative, anti-inflammatory and neuroprotective effects. A number of recent observations suggest that the induction of heme oxygenase-1 (HO-1) inhibits inflammation and tumorigenesis. In the present study, we determined the effect of fraxetin on HO-1 expression in HaCaT human keratinocytes and investigated its underlying molecular mechanisms. Methods: Reverse transcriptase-PCR and Western blot analysis were performed to detect HO-1 mRNA and protein expression, respectively. Cell viability was measured by the MTS test. The induction of intracellular reactive oxygen species (ROS) by fraxetin was evaluated by 2′,7′-dichlorofluorescin diacetate staining. Results: Fraxetin upregulated mRNA and protein expression of HO-1. Incubation with fraxetin induced the localization of nuclear factor-erythroid-2-related factor-2 (Nrf2) in the nucleus and increased the antioxidant response element-reporter gene activity. Fraxetin also induced the phosphorylation of Akt and AMP-activated protein kinase $(AMPK){\alpha}$ and diminished the expression of phosphatase and tensin homolog, a negative regulator of Akt. Pharmacological inhibition of Akt and $AMPK{\alpha}$ abrogated fraxetin-induced expression of HO-1 and nuclear localization of Nrf2. Furthermore, fraxetin generated ROS in a concentration-dependent manner. Conclusions: Fraxetin induces HO-1 expression through activation of Akt/Nrf2 or $AMPK{\alpha}/Nrf2$ pathway in HaCaT cells.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.3
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• pp.33-38
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• 2021

Type 1 diabetes mellitus (T1DM) is caused by insufficient production of insulin, which is involved in carbohydrate metabolism. Type 2 diabetes mellitus (T2DM) has insulin resistance in which cells do not respond adequately to insulin. The purpose of this study was to estimate the characteristics of type 1 diabetes using streptozotocin-treated mice (STZ-mouse). The sera samples were collected from the models of hyperglycemic mouse and healthy mouse. Based on the pair-wise comparison, five metabolites were found to be noticeable: glucose, malonic acid, 3-hyroxybutyrate, methanol, and tryptophan. It was very natural glucose was upregulated in STZ-mouse. 3-hyroxybutyrate was also increased in the model. However, malonic acid, tryptophan, and methanol was downregulated in STZ-mouse. Several metabolites acetoacetate, acetone, alanine, arginine, asparagine, histidine, lysine, malate, methionine, ornithine, proline, propylene glycol, threonine, tyrosine, and urea tended to be varied in STZ-mouse while the statistical significance was not stratified for the variation. The multivariate model of PCA clearly showed the group separation between healthy control and STZ-mouse. The most significant metabolites that contributed the group separation included glucose, citrate, ascorbate, and lactate. Lactate did not show the statistical significance of change in t-test while it tends to down-regulated both in DNP and Diabetes.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.147-157
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• 2022

Electrochemical characteristics and damage behavior of 6061-T6 aluminum alloy used as a battery housing material for electric vehicles were investigated in solution simulating the acid rain environment with chloride concentrations. Potentiodynamic polarization test was performed to analyze electrochemical characteristics. Damage behavior was analyzed through Tafel analysis, measurement of damage area, weight loss, and surface observation. Results described that corrosion current density was increased rapidly when chloride concentration excceded 600 PPM, and it was increased about 7.7 times in the case of 1000 PPM compared with 0 PPM. Potentiodynamic polarization experiment revealed that corrosion damage area and mass loss of specimen increased with chloride concentrations. When chloride concentration was further increased, the corrosion damage area extended to the entire surface. To determine damage tendency of pitting corrosion according to chloride concentration, the ratio of damage depth to width was calculated. It was found that the damage tendency decreased with chloride concentrations. Thus, 6061-T6 aluminum alloy damage becomes larger in the width direction than in the depth direction when a small amount of chloride is contained in an acid rain environment.

• Journal of Korean Clinical Health Science
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• v.10 no.1
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• pp.1569-1577
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• 2022

Purpose: This study was conducted to investigate academic self-efficacy, metacognition and major satisfaction which influence learning flow in nursing students. Method: The subjects of this study were 239 nursing students in D college. Structured questionnaire was self-administered from May 3 to 30, 2021. The date was analyzed by t-test, ANOVA, Pearson'correlation coefficients, stepwise and multiple regression using SPSS/WIN 22.0. program. Results: In academic self-efficacy, there were significant differences in age. In metacognition, there were significant differences in age, school record. There was a statistically positive correlation between learning flow and academic self-efficacy(r=.211, p=.001), metacognition(r=.357, p<.001), major satisfaction(r=.281, p<.001). The factors influencing learning flow were metacognition(t=.682, p<.001), major satisfaction(t=2.147, p=.023)Multiple regression analysis description is 61.2%. Conclusion: To improve the learning outcomes for nursing students, it is necessary to develop teaching program and curriculum for increasing, metacognition and major satisfaction.