• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.372-379
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• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.78-89
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• 2007

Two design examples of deep foundations for high-rise buildings on soft ground are introduced in this paper. The first one is a 54-story building in Ho-Chi-Minh city, Vietnam, which was designed to be founded on $2.8m{\times}1.0m$ barrette foundations with approximately 60m to 75m depth. Based on a number of design guides and existing load test data from the construction sites in Ho-Chi-Minh city, the capacity of a barrette foundation in sand or clay layered ground was calculated to be 17.2MN to 27.8MN depending on the installing depth. The second one is a 40-story building in Baku city, Azerbaijan, which was designed to be supported by 2.0m diameter bored pile foundations with approximately 23m depth. As analytical or empirical guides for the local ground conditions were very limited, the design procedure from the SNiP Code, one of Russian specifications, was adopted and used to calculate the pile capacity. The capacity of bored pile foundation in highly weathered soil was expected to be 14.8MN to 15.5MN depending on the boring depth.

• Journal of Korean Academy of Nursing
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• v.41 no.5
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• pp.633-641
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• 2011

Purpose: The purpose of this study was to propose and test a predictive model that could explain and predict Korean nurses' turnover intentions. Methods: A survey using a structured questionnaire was conducted with 445 nurses in Korea. Six instruments were used in this model. The data were analyzed using SPSS 15.0 and Amos 7.0 program. Results: Based on the constructed model, organizational commitment, and burnout were found to have a significant direct effect on turnover intention of nurses. In addition, factors such as empowerment, job satisfaction, and organizational commitment were found to indirectly affect turnover intention of nurse. The final modified model yielded ${\chi}^2$=402.30, p<.001), ${\chi}^2$/df=2.94, RMSEA=0.07, RMR=0.03, GFI=0.90, AGF=0.87, NFI=0.88, CFI=0.92 and good fit indices. Conclusion: This structural equational model is a comprehensive theoretical model that explains the related factors and their relationship with turnover intention in Korean nurses. Findings from this study can be used to design appropriate strategies to further decrease the nurses' turnover intention in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.294-303
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• 2017

As the elderly population increases, the prevalence of various geriatric chronic diseases and dementia diseases is also rapidly increasing; accordingly, dementia is becoming a major concern of our society. In this study, 48 elderly patients with mild cognitive impairment located in K district were selected from a group of experimental groups in one building and a control group in one building and evaluated for blood homocysteine levels and cognitive function changes after 4,8, and 12 weeks of taking vitamin supplements. The Chi-squared test, Fisher's Exact test, independent t-test, repeated measures ANOVA, contrast test, repeated measures ANCOVA, and Wilks' lambda test were utilized to analyze the data. The results revealed that the cognitive function of the experimental group was significantly higher than that of the control group at 12 weeks (p<0.05), and so, the experimental group higher than that of the control group (p<0.01), the effect of taking vitamins was significantly increased, indicating that homocysteine was decreased relative to the control group. Therefore, vitamin supplements may prevent decreases in cognitive functions and dementia among elderly patients with mild cognitive impairment.

• Journal of The Korean Association For Science Education
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• v.33 no.6
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• pp.1237-1247
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• 2013

The purposes of this study are 1) to revalidate the developed Measuring Instrument Systems Thinking and 2) to compare systems thinking skills between gifted and non-gifted high school students. For the test, 116 gifted science students and 553 non-gifted students were sampled from high schools. Exploratory factor analysis and confirmatory factor analysis were performed and Independent t-test was performed using the average of the two groups. The finding of the exploratory factor analysis indicated 5 factors in the model with 4 items per single factor. The result of confirmatory factor analysis was generally appropriate and acceptable (5 factor model: ${\chi}^2/df$ : 2.765, TLI=.907, CFI=.929, IFI=.930, RMSEA=.044). The reliability for 20 items turned out to be high because the Cronbach's alphas were at .875 and .693~.751 per each factor. In addition, the result of t-test showed that systems thinking skills among gifted science students were significantly higher than non-gifted students. This study could be expanded to measuring systems thinking with qualitative research tools and to various school levels.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.1-6
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• 2014

Power system of the tilt-duct VTOL aerial robot has been developed. This paper focuses on the power train with small liquid-type engine for the R/C boat and presents the test results with design procedures. The hardware aspects of the power system include details about the hardware configurations for the interfaces with the vehicle. The ground test and tether test for measuring the thrust performance of vehicle and evaluating the endurance of power train carried out.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.9
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• pp.818-826
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• 2002

Since multipath phenomenon frequently occurs when a Global Positioning System receiver is placed in urban area crowded with large buildings, efficient mitigation of multipath effects is necessary to resolve. In this paper, we propose a new multipath detection technique that is useful in real-time positioning with a general Global Positioning System receiver. The proposed technique is based on a channelwise multipath test statistic that efficiently indicates the degree of fluctuations induced by multipath error. The proposed multipath test statistic is operationally advantageous because it does not require any specialized hardware nor any pre-computation of receiver position, it is directly related to standard $\chi$$^2$-distributions, and it can adjust the detection resolution by increasing the number of successive measurements. Simulation and experiment results verify the performance of the proposed multipath detection technique.

• Child Health Nursing Research
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• v.12 no.1
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• pp.104-113
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• 2006

Purpose: This study was conducted to develop and evaluate the effectiveness of a prenatal parental role education program. Methods: The participants were healthy primiparous women and their healthy newborn babies. 57 mother-infant diads(27 in the intervention group, 30 in the control group). For the intervention group, an additional 4 prenatal parental role education programs and 2 postnatal telephone calls(1st & 3rd week after birth) were provided. Data were analyzed by frequency, chi-square test, t-test and repeated measures ANOVA using SPSS PC+ 10.0 program. Results: Significant differences were found in self-confidence in maternal role performance, mother-infant interaction and infant physical growth between the two groups. This result indicate that the intervention program was effective in improving self-confidence in maternal role performance, mother-infant interaction and in facilitating infant physical growth. Conclusions: The prenatal parental role education program developed by the author was a very effective program in promoting maternal self-confidence, mother-infant interaction, and fostering infant's physical growth at 4 weeks after infant's birth.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.63-72
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• 1993

The purpose of this study was to investigate nutritional knowledge, nutrition attitude and food preference among middle school students and to evaluate the effect of nutrition deucation in middle school. The survey was conducted from June 15, to June 25, 1993 by questionnaires which was composed of ntrition knowledge test, nutrition attitude test and food preference test. The subjects of this study were composed of 106 male and 105 female students of middle school. The results obtained were summarized as follows: Nutrition knowledge score Nutrition Knowledge score Nutrition knowledge score of female group was significantly higher than that of male group at P<0.001 Nutrition Attitude Score Nutrition Attituds Score of female group was significantly higher than that of male group at P<0.001 Correlations between nutrition knowledge and nutrition attitude scores in both group were significant Food Preferences Preferences for pork cutlet, hot dog, chicken, beef, kim chi, cooked rice, ptoato were high in both groups.

• Fashion & Textile Research Journal
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• v.10 no.2
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• pp.173-180
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• 2008

The purposes of this study are to investigate what star marketing is and to examine whether star marketing influences clothing purchase behavior of adolescents or not. The concept and the instances of star marketing were reviewed and the characteristics and clothing behavior of adolescence were analyzed. The data were obtained from questionnaires completed by 341 middle and high school students and analyzed by frequency, t-test, chi-square test, cluster analysis, ANOVA, and Scheffe test. The Cronbach's alphas were calculated for the internal consistency. The results of the study are as follows. The sample was classified into three groups(high interest/high awareness group, high interest/low awareness group, and low interest/low awareness group) by the interest of TV watching and TV stars, the identification with TV stars, and the awareness and the interest of star marketing. There were significant differences in clothing purchase motives, the use of information sources, clothing buying places, clothing purchase frequency, and clothing expenditure among three groups.