• Journal of Families and Better Life
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• v.30 no.2
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• pp.189-196
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• 2012

The purpose of this study was to investigate trajectories of relational aggression in preschool children. The latent growth curve model was used to examine relational aggression in 3 to 5 year olds. The participants were 3-year-old children recruited from preschools and daycare centers. The children's verbal ability was assessed by interview and teachers completed measurements of negative emotionality and relational aggression. The findings suggest that relational aggression decreased during the preschool years. Gender, language ability, and negative emotionality showed positive effects on the initial level of relational aggression. Moreover, gender and negative emotionality had negative effects, however, language ability had positive effects on the change rate of relational aggression.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.2
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• pp.40-45
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• 1986

In this paper, the I-resistance curve of low-carbon steel with 3 mm thickness was investigated for various crack ratios. The experiments were carried out for the center cracked tension (CCT) specimen with about 50 mm width on an instron machine. The plane stress fracture toughness obtained by the Simpson's formula was Ii. = 24.96 kgffmm. Simpson's formula which considers crack growth in obtaining J integral showed more conservative lin than Rice's and Sumpter's. For materials that may be approximated by the Ramberg and Osgood stress strain law, the relevant crack parameters like the J integral, load line displacement are approximately normalized. Crack driving forces in terms of the I integral are computed for low-carbon steel CCT specimen using the above estimation scheme. Comparison of the prediction with actual experimental measurements by Simpson's formula showed good agreement for several different sized specimen.

• Transactions of Materials Processing
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• v.21 no.3
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• pp.151-159
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• 2012

Finite element simulations were conducted to investigate the influence of grain growth in the superplastic blow forming process. A microstructure-based constitutive model considering grain growth effects is proposed and used in the simulations. Also, a grain growth rate equation accounting for both static and dynamic grain growth is implemented. The simulations were made using a 2D plane-strain model for constrained blow forming and an axisymmetric model for free bulging. These two models showed different features during the forming stages. However, the forming pressure-time curve and the thickness distribution obtained by both simulations explained well the deformation hardening induced by the grain growth during superplastic forming. This study shows that grain growth is an important factor in determining the material behavior during superplastic deformation.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.148-158
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• 2013

Generally, building construction projects have a complex decision-making process because of the participation of various agents. In this situation, a final decision is arrived at by relying on subjective judgments based on the experience of project participants. For this reason, a method of assessing the objectivity of opinions is needed. In previous studies, the multi-criteria decision making method was applied to arrive at a final decision objectively, but this method has a limitation, in that the experience of each decision maker is not considered differently in the decision making process. Therefore, this study proposed a theoretical model using the S-shaped growth curve and regression analysis by building construction project type to quantitatively estimate decision-making reliability according to the experience of individual project participant`s. The developed model could be added to the Multi-criteria decision making method, and secure the objectivity and reliability of project participants' final opinion.

• Convergence Security Journal
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• v.12 no.3
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• pp.115-121
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• 2012

Software failure time presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing. For data analysis of software reliability model, data scale tools of trend analysis are developed. The methods of trend analysis are arithmetic mean test and Laplace trend test. Trend analysis only offers information of outline content. In this paper, we discuss forecasting failure time case of failure time censoring. In this study, we predict the future failure time by using the curve regression analysis where the s-curve, growth, and Logistic model is used. The proposed prediction method analysis used failure time for the prediction of this model. Model selection using the coefficient of determination and the mean square error were presented for effective comparison.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.57-64
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• 2005

Samples of Corbicula japonica Prime of Jujin estuary in Gochang were collected from July 2000 to September 2001. Age of C. japonica was determined from the rings on the shell. The relationship between shell length and ring radius in each ring group was expressed as a regression line. Therefore, there is a correspondence in each ring formation. Based on the monthly variation of the marginal index (MI') of the shell, it is assumed that the ring of this species was formed once a year during the period of February and March. The relationship between shell length (SL; mm) and total weight (TW; g) was expressed by the following equation: TW = 1.0942 ${\times}10^{-4}SL^{3.3217}$ ($r^2$ = 0.9905). Shell length (SL) and shell height (SH; mm) was highly correlated with shell height as the following equation: SH = 0.9174 SL - 0.9935 ($r^2$ = 0.9885). The shell length (SL) - shell width (SW) relation was also expressed by the following equation; SW = 0.5925 SL - 1.1706 ($r^2$ = 0.9726). Growth curves for shell length and total weight fitted to the von Bertalanffy's growth curve were expressed as: $$SL_t = 46.4861[1-e^{-0.3383(t+0.0958)}]$$, $$TW_t = 34.54[1-e^{-0.3383(t+0.0958)}]^3.3217$$.

• Journal of Nutrition and Health
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• v.35 no.9
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• pp.926-931
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• 2002

The antimicrobial properties of extracts of Prunus mume were tested on Salmonella paratyphimurium and S. typhimurium. First, the Prumus mume was extracted with methanol at several temperatures, and then fractionation of the methanol extracts from Prunus mume was carried out by using petroleum ether, chloroform, ethyl acetate or butanol. Secondly, absorption column chromatoraphy (using a Diaion HP 20) was conducted to eliminate some water soluble materials that might inhibit the antimicrobial activity of some extracts. The antimicrobial activitry of each of the Prunus mume extracts was determined using a paper disc method against several food-borne pathogens, The growth inhibition curve was determine using butanol extracts of Prunus mume against Salmonella typhimurium. The extraction temperature did not have any significant effect on the yield of the extract or on the level of antimicrobial activity. The butanol extract of Prunus mume showed strong antimicrobial activity against Salmonella paratyphimurium and S. typhimurium; a 1,000 ppm of butanol extract of Prunus mume retared the growth of S. typhimurium up to 36 hours. (Korean J Nutrition 35(9) : 926~931, 2002)

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.147-153
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• 2003

In this study, Artemisia capillaries, which has been used as a folk remedy, was investigated for its antimicrobial activity. First, the Aremisia capillaris was extracted with methanol at room temperature, and fractionation of the methanol extracts from Artemisia capillaris was carried out using petroleum ether, chloroform, and ethyl acetate. Second, the antimicrobial activity of the Artemisia capillaris extracts was determined using a paper disc method and minimum inhibitory concentration of ethyl acetate extracts from Artemisia capillaris against food-borne pathogens and food spoilage bacteria was measured. Finally, the growth inhibition curve was determined using ethyl acetate extracts of Artemisia capillaris against Staphylococcus aureus and Salmonella typhimurium. The ethyl acetate extract of Artemisia capillaris showed strong antimicrobial activity against S. typhimurium at a concentration of 1,000 ppm. The 3,000 ppm of ethyl acetate extract from Artemisia capillaris retarded the growth of S. aureus and S. typhimurium for up to 6 hours.

• The Journal of Pediatrics of Korean Medicine
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• v.27 no.4
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• pp.50-56
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• 2013

Objectives The purpose of this study is to evaluate the effect of the herbal medicine in treating digestive system problem on children's growth. Methods We studied 135 children who visited ${\bigcirc}{\bigcirc}$ oriental medical hospital to treat digestive system problem from March 2010 to February 2012. We measured their height and body weight on their first time visit and a year later. We compared them using the Growth Statistics Curve made by the Korean Association of Pediatrics, 2007. Results Generally, total children's average height and weight were significantly increased after the herbal medicine. The difference between the height and weight of treated children and the average height and weight was significant. Conclusions Herbal medicine to treat disorder of digestive system helped growth of children.

• Journal of Power System Engineering
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• v.8 no.4
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• pp.11-16
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• 2004

In this study, to investigate the effects of omitting low-amplitude cycles from a flight-simulation loading, crack growth tests were conducted on 2124-T851 aluminum alloy specimens. Three test spectra were generated by omitting small load ranges as counted by the rain-flow count method. The crack growth test results were compared with the data obtained from the flight-simulation loading. The experimental results show that the ranges equal to or smaller than 5% of the maximum load do not contribute to crack growth behavior because these are below the initial stress intensity factor range. Omitting these from the flight-simulation loading, test time can be reduced by 54%. However, in the case of omitting the load ranges below 15% of the maximum load, crack growth rates decreased, and crack growth curve deviated from the crack growth data under the flight-simulation loading because loading cycles above fatigue fracture toughness were omitted.