• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.888-895
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• 2015

This paper shows an approximate equation which calculates a flapping angle of blade for verification of KUH safety area. The flapping behavior of blade must be reviewed in an aspect of safety because of a collision possibility with airframe. However, it is difficult to measure an exact flapping angle during flight. A prediction equation of a coning angle is derived from aeromechanics and that of a dynamic flapping angle is derived from analysis results in development phase, respectively. Following, the equations are verified by comparison the flapping angle through an aircraft simulation test to a calculation. Finally, the safety area, which was established in development phase, is verified by calculating a flapping angle during the flight which is required by the terms of safety based on AC29 and FAR29.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.534-538
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• 2003

Final disposal of radioactive waste generated from Nuclear Power Plant (NPP) requires the detailed knowledge of the natures and quantities of radionuclides in waste package. Many of these radionuclides are difficult to measure and expensive to assay. Thus it is suggested to the Indirect method by which the concentrations of DTM (Difficult-to-Measure) nuclide is decided using the relation of concentrations (Scaling Factor) between Key (Easy-to-Measure) nuclide and DTM nuclide with measured concentrations of Key nuclide. In general, scaling factor is determined by using of log mean average (LMA) and regression. These methods are adequate to apply most corrosion product nuclides. But in case of fission product nuclides and some corrosion product nuclides, the predicted values aren't well matched with the original values. In this study, the models using artificial neural network (ANN) for C-14 and Sr-90 are compared with those using LMA and regression. The assessment of models is executed in the two parts divided by a training part and a validation part. For all of two nuclides in the training part, the predicted values using ANN are well matched with the measured values compared with those using LMA and regression. In the validation part, the accuracy of the predicted values using ANN is better than that using LMA and is similar to or better than that using regression. It is concluded that the predicted values using ANN model are better than those using conventional model in some nuclides and ANN model can be used as the complement of LMA and regression model.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.422-426
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• 1984

According with variations in principal agronomic traits of fourteen malting barley cultivars as affected by different seeding methods and seeding rates. the analysis and interpretation of correlation coefficients and path coefficients was intended. From all treatments (seeding methods and rates), the positive significant relations detected between flowering days and maturing days, however the negative between maturing days and culm length, number of grains per spike, yields, and between 1000 grain weight and one liter weight, respectively. Direct effects on the yields were greatest by number of grains per spike in case of narrow-spaced row seeding and number of spikes per m$^2$ and number of grains per spike among others in broadcast seeding method On the other hand, indirect effects were not recognized in any treatments.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.1-9
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• 2015

Due to the increasing number of deteriorated bridges worldwide, the importance of maintenance and replacement of existing bridges are being emphasized. Cast-in-place concrete deck which is mainly applied to deck replacement of existing bridges have problems such as deterioration concerns by initial crack, labor cost increase, difficulties of maintenance and replacement, construction time increase, and indirect cost increase by traffic congestion. On the contrary, a precast concrete deck is considered as an effective alternative because of its quality assurance and accelerated construction. The connection method ensuring the required strength and durability is especially important, because the connection part of the precast concrete deck is vulnerable to cracks and leakage. Therefore, this study proposes precast bridge decks with ribbed connection which are more improved than existing bridge deck joints, and flexural performance is verified through various parameter tests.

• Korean Journal of Health Education and Promotion
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• v.25 no.2
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• pp.31-46
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• 2008

The purpose of this research is to increase adults' quality of life by improving oral health. Total 572 people participated in this study in Young-Nam area. Survey research method was used to measure various tools of participants' general index, subjective view of oral health status, oral health knowledge, oral health practice, dietary pattern, OHIP-14, THI, QOL for analyzing the effect on quality of life. The result of the study is summarized as follows; 1. Oral health knowledge has positive effects on oral health practice (0.442), dietary pattern(0.343). Diet has positive effects on OHIP-14(0.187) and OHIP-14 has significant positive effects on THI(0.564). THI also has positive effects on QOL(0.380). But oral health practice index has slight effects on OHIP-14(0.056). 2. Indirect effect indexes on QOL are OHIP-14(0.214), diet(0.040), oral health knowledge(0.019), oral health practice(0.012) listed in order of effect size, and the biggest direct effect on QOL is from THI(0.308). The result of this study shows oral health and total health are important to improve the quality of life. And the knowledge about oral health dietary pattern should be important to improve oral health. But, even with high level of oral health knowledge, the oral health practice is at low level. Health education developing program should be needed. It is required to present basic data which represent adults with national view by extracting groups using sample probability methods as of next task of this study.

• Journal of the Korean Home Economics Association
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• v.45 no.2
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• pp.1-22
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• 2007

The purpose of this study was to investigate the effect of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression. Subjects of this study consisted of 342 young children drawn from seven preschools in Cheongju city. The pilot study was used to examine the applicability of survey instrument. Data were analyzed by the method of frequency, percentage, Cronbach' ${\alpha}$, factor analysis, T-test. F-test, and Duncan post-hoc test using SPSSWIN program. The test of model was done with analysis of correlational matrix in LISREL VII package using a maximum likehood estimation. The results of this research were as follows: First, there were statistically significant differences in mother's characteristics consisting of neurosis symptom and extroversions, disciplinary methods consisting of coercive-punishment and indifferent-irresponsibility, young children's emotional regulation, and young children's aggression consisting of relation and overtness according to some socio-demographic variables. Girls had the higher emotional regulation than boys. Second, the direct effects of disciplinary methods and emotional regulation on boys' aggression were different in between relational and overt aggression. Third, the variables predicting boys' emotional regulation directly were the same in both relational and overt aggression. Forth, the direct effect of mother's characteristics on disciplinary methods was different in between coercive-punishment and indifferent-irresponsibility. Fifth, the indirect effects of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression were partly supported in this study. Sixth, the theoretical model of the impact of mother's characteristics, disciplinary methods, and young children's emotional regulation on young children's aggression was different according to gender.

• Human Ecology Research
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• v.56 no.2
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• pp.133-144
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• 2018

The study examined the longitudinal relations of preschool children's peer interaction, linguistic and cognitive abilities, and self-control, while taking into account gender differences. The study was conducted with 671 preschoolers from the $5^{th}$, $6^{th}$, and $7^{th}$ wave of the Korean Children and Youth Panel Study (KCYPS). Data were analyzed by means of basic descriptive statistics, Pearson's correlations, and structural equation modeling analysis. Bootstrapping method was also used to determine the significance of indirect effects. The analysis were conducted to find the longitudinal effects of peer interaction at the age of 4 on their self-control at the age of 6, and the mediating effects of linguistics and cognitive abilities at the age of 5 on its associations. The results indicated gender differences among the variables. According to multi-group analysis, there was a significant influence of 4 years' peer interaction on subsequent 5 years' linguistic and cognitive abilities but also on 6 years' self-control across time for boys; however, no significant direct effect of peer interaction on self-control was found for girls. Based on the findings of this study, it can be implied that it is necessary to apply different methods for boys and girls to promote self-control from the influence of peer interaction and linguistic and cognitive abilities.

• Korean Journal of Social Welfare
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• v.60 no.3
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• pp.107-127
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• 2008

This study examined the direct or indirect effects through burnout of sources of work stress of child welfare employees on turnover intentions. In addition, the study investigated the moderating effects of stress coping resources, which was hypothesized to buffer the negative effects of the sources of work stress on burnout. The study data were collected from 190 social workers in foster care services and child protective services. As a statistical method, structural equation model was employed. The study results showed that sources of work stress affect indirectly though raising the level of burnout. The study did not find the moderating effects of stress coping resources. Based on the results, implications for child welfare practice were discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.424-427
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• 2002

In this papaer, there is a basic research for the development of the Hybrid digital radiation detector with a new system, make up for existing digital radiation detector of direct/indirect method with a weak point. for enhance the efficiency characteristics of signal response from X-ray detector using the a-Se, We make sample with various kinds of layer, through the ratio of As(0.l%,0.3%,0.5%,1%,1.5%,5%,10%). We measure net charge with a leakage current and photo current for electric charateristics. Ratio of As in a-Se consist of 7 stage, It made of using the thermal deposition system, In the made of samples, we made multi layer using the EFIRON optical adhesives from phosphor layer consist of Oxybromide$(BrO_2)$. As a result of X-ray measurement, the best result is ; leakage current(0.30nA/cm2), net charge(610.13pC/cm2/mR) when the condition is voltage(9V/um), 0.3% ratio of As in multi layer(BrO2 + a-Se)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.416-419
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• 2002

There are being two prominent studying for Digital Radiography. Direct and Indirect method of Digital Radiography are announced for producing high quality digital image. The one is using amorphous selenium as photoconductor and the other is using phosphor layer as a light conversion. But each two systems have strength and weakness such as high voltage and blurring effect. In this study, we investigated the electrical characteristic of $multi-layer\left(CaWO_{4}+a-Se \right)$ as a photoconductor according to the changing arsenic composition ratio. This is a basic research for developing of Hybrid digital radiography which is a new type X-ray detector. The arsenic composition ratio of a-Se compound is classified into 7 different kinds which have 0.1%, 0.3%, 0.5%, 1%, 1.5%, 5%, 10% and were made test sample throught thermo-evaporation. The phosphor layer of $CaWO_4$ was overlapped on a-Se using EFIRON optical adhesives. We measured the dark and photo current about the test sample and compared the electrical characteristic of the net charge and signal-to-noise ratio. Among other things, test sample of compound material of 0.3% arsenic showed good characteristic of $2.45nA/cm^2$ dark current and $357.19pC/cm^2/mR$ net charge at $3V/{\mu}m$.