• Development and Reproduction
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• v.15 no.3
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• pp.197-204
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• 2011

Egg activation is a crucial step that initiates embryo development upon breaking the meiotic arrest. In mammalian, egg activation is accomplished by fusion with sperm, which induces the repeated intracellular $Ca^{2+}$- increases ($[Ca^{2+}]_i$ oscillation). Researches in mammals support the view of the $[Ca^{2+}]_i$ oscillation and egg activation is triggered by a protein factor from sperm that causes $[Ca^{2+}]_i$ release from endoplasmic reticulum, intracellular $[Ca^{2+}]_i$ store, by persistently activation of phosphoinositide pathway. It represents that the sperm factor generates production of inositol trisphosphate ($IP_3$). Recently a sperm specific form of phospholipase C zeta, referred to as PLCZ was identified. In this paper, we confer the evidence that PLCZ represent the sperm factor that induces $[Ca^{2+}]_i$ oscillation and egg activation and discuss the correlation of PLCZ and infertility.

• Korean Journal of Human Ecology
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• v.14 no.1
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• pp.1-13
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• 2005

This study has a purpose of developing a scale to evaluate maternal beliefs on preschool children's education. The subjects were 307 mothers of preschool children in Gwang-ju. The methods for data analyses included a factor analysis for construct validity, Pearson correlations between beliefs and learning-related activities for construct validity, and Cronbach's a for reliability. 4 factors were found, through literature review, in parental beliefs: passive learning, active learning, instruction, and expectation for academic-related skills acquisition. Factor analysis revealed that the 4-factor solution is the best fit. Correlations between beliefs and learning-related activities were statistically significant. Cronbach's a ranged from .65 to .87 for 4 sub-scales. It was concluded that the maternal beliefs scale is acceptable for use.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2258-2261
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• 2010

Since national mid-term target for GHG reduction was determined in 2009, various efforts in transportations have been prepared. Generally, the GHG emission of transportation is calculated using the emission factor published from IPCC guideline(2006). However, it is necessary to develop new emission factors considering the properties of transportation as well as fuel. In Korean railroad, main emission sources are the consumption of diesel and electricity from railcar operation. The GHG emission of electric-powered railcars can be estimated using national electric emission factor, but diesel-powered railcars show different trends. The purpose of this study was to establish the development plans of emission factors for diesel-powered railcars. As a result, the emission factors of diesel-powered railcars were classified into railcar type, engine type and life cycle, notch, load, and traffic volume. In future, several emission factors with this category will be presented quantitatively through field tests with the order of priority.

• Journal of Agricultural Extension & Community Development
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• v.23 no.4
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• pp.375-385
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• 2016

Since the discussion on solving some problems in modern socity began in the late 1990s, the interest in students' character education has increased. This study aims to identify the factors influencing educational needs assessment for character education in Korea. A self-administered survey was obtained from 318 students in a university. Three factors extracted from factor analysis were individual, interpersonal, social character factor. Results showed that the determinants influencing character educations are academic achievement and volunteer activities for individuals character, academic achievement and school activities in campus for interpersonal and social character educational factor. The findings should be of interest to practitioners to develop education programs for students.

• East Asian Economic Review
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• v.20 no.3
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• pp.339-363
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• 2016

This paper analyzes why the global financial crisis in 2008 severely affected Asia's trade. Asia has been suffering from the falls in export demand from developed countries. However the abrupt trade declines in Asia are not fully explained by reactions to this as in previous experiences. The question is why the financial crisis in 2008 brought about the abrupt and deep collapse in world trade, while other world-wide recessions had more moderate effects on world trade. This paper shows that the dynamic relationship between trade and trade finance is one important factor in explaining this question. This paper also applies the Granger (causality) test to uncover different relationships in the developed and developing economies and show different results for different countries in Asia. We employ a Markov-Switching FAVAR (Factor Augmented VAR) to show that global liquidity shocks are important factors in explaining the huge and abrupt trade drops in Asia.

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.75-79
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• 2008

Nerve growth factor (NGF) is a protein plays a major role in the development and maintenance of central and peripheral nervous system. Recent data suggest that reduced availability of NGF may play a significant role in the pathogenesis of diabetic $polyneuropathy.^{1)}$ In our previous study, steroidal saponin from Liriope platyphylla showed neurotrophic effect by stimulation of NGF synthesis and activation of tyrosine kinase $signaling.^{2)}$ In this study, we examined the neurotrophic effect of Liriope platyphylla (LP); which was from Mylyang(MYL) and Cheongyang(CHE), and Ophiopogon japonicus (CHI) on in vitro and in vivo model for the comparison of their NGF induction. We quantitatively analyzed spicatoside A in the LP and CHI by HPLC. And we investigated the correlation between the contents of spicatoside A and NGF induction efficacy on PC 12 cells and mouse serum. These results suggest that spicatoside A may enhance NGF induction in animal model.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.517-520
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• 2005

This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of cement mortar by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

• Journal of the Korean Home Economics Association
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• v.39 no.1
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• pp.221-232
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• 2001

The purpose of this study was to develop a scale for evaluation of preschool children's peer competence and to examine its validity and reliability. The 15 items of the preliminary scale were completed by teachers, and peer rating scale for assessment of peer acceptance was administered to 365 children 5 to 6 years of age. The methods for data analysis included item analysis, factor analysis for construct validity, Pearson correlations between teacher's ratings of peer competence and children's ratings of peer acceptance for concurrent validity, and Cronbach's u for reliability. The 15 items of the scathe were found be satisfactory in terms of item response distribution and item discrimination. Factor analysis revealed that a 3-factor solution was the best fit: sociability, prosocial behavior, leadership in peer relations. Correlations between teacher's ratings and children's ratings were as significant. Cronbach'so ranged from .88 to .93 for three subscales and .93 for the total scale. It was concluded that the psychometric properties of the peer competence scale in general were acceptable for use.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.703-706
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• 2004

This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of cement mortar by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.9-13
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• 1996

The high precision of electrical power and energy measurements with wide range of frequency and power factor can be achieved by using the thermo-electrical power comparators. The paper describes the development of a precision power measuring system by using a ac/dc power comparator for measurement of power. Based on a thermal principle, the instrument performs ac-dc transfer for ac power measurements in the range of currents from 0 to 5 $A_{ms}$ , voltages from 0 to 240 $V_{ms}$ , power factors from 0 to 1 and frequencies from 0 to 1000 Hz. Two thermal converters with two heater are used in the functional element of the comparators. The ac-dc transfer accuracy is better than 20 ppm at unity power factor and better than 50 ppm at 0.5 power factor. (author). 8 refs., 5 figs., 3 tabs.