• Proceedings of the Korean Magnestics Society Conference
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• 2000.05a
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• pp.106-107
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• 2000

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.109-113
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• 2003

The study was carried out to investigate the effects of morphology, preservation and reproductive cycle of oocytes in vitro maturation of cats oocytes and development of IVM embryos. The results were summarized as follows : 1. Nuclear status of GV and MI of in vitro cultured(24 h) oocytes with and whithout cumulus cells were 74.3% and 25.7%, 28.6% and 11.4%, 77.1% and 5.7%, respectively, The rate of oocytes with cumulus cells was higher than that of denuded oocytes. 2. Nuclear status of GV and MI of in vitro cultured(24 h) oocytes recovered from ovaries collected at different stages of the reproductive cycle(inactive, follicular and luteal) were 88.6% and 6.5%, 60.0% and 11.4%, 77.1% and 5.7%, respectively. 3. Nuclear status of fresh and salts-stored oocytes with and whithout cumulus cells were 74.3%, 25.7% and 37.1%, 11.4% and 57.1%, 13.3%, 17.1%, 3.3%, respectively. The rate of oocytes with cumulus cells(13.3%∼74.3%) was higher than that of denuded oocytes(3.3%∼57.1%).

• Korean Journal of Clinical Laboratory Science
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• v.38 no.1
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• pp.72-81
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• 2006

Wee1 is a kinase regulator of the M-phase promoting factor (MPF; a complex of cdc2 and cyclin B1). The present study was undertaken to determine the role(s) of wee1 in the early stages of mouse ovarian follicles. The expression of wee1 and the correlated cell-cycle components, namely cdc2, cyclin B1, and cdc25C, were evaluated by immunohistochemistry. In addition, the expression of Tyr15-phosphorylated cdc2 (cdc2-p) was also examined to determine whether wee1 kinase phosphorylates cdc2 existed. Each component except cdc25C was found cytoplasmic in the oocytes at all stages of follicles, while cdc25C was not detected in primordial follicles. It was found primarily in ovarian somatic cells and to a small extent in granulosa cells of the growing follicles. To further confirm the expression of cell-cycle components in the primordial follicular oocytes, day1 ovaries were enzymatically and mechanically dissociated, then oocytes were isolated from somatic including pre-granulosa cells, and we confirmed that cdc2-p was expressed in oocytes of primordial follicles. From the results of the present study, we concluded wee1, without the counteracting cdc25C, would cause meiotic arrest of oocytes by the inhibitory phosphorylation of cdc2. The expression of all these proteins in the granulosa cells of growing follicles may regulate their mitosis concurrently with the growth of oocytes and follicles.

• Food Science and Preservation
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• v.16 no.2
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• pp.223-229
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• 2009

The effects of 0.01%(w/v) chitosan-ascorbate(CA) and 10 ppm morea on the number of total microbes, Escherichia coli levels, and growth of food poisoning bacteria in dombaeki during storage at $10^{\circ}C$ over 6 days were investigated. Total microbes in meat, cartilage, and skin of untreated samples increased by 4.24, 3.81, and 2.20 logs compared to the zero timepoint, respectively, but, in CA-treated samples, counts fell by 2.66, 2.37, and 1.24 logs. Total microbial levels in morea-treated meat, cartilage, and skin showed similar tendencies but the effects were slightly less than seen in CA-treated samples. E. coli numbers in CA-treated meat, cartilage, and skin stored for 6 days decreased by 1.69, 1.25, and 1.52 logs respectively, compared with control samples. Morea-treated samples showed similar falls, but the effects were again slightly less than seen after CA-treatment. Both Salmonella and Vibrio parahaemolyticus were detected in untreated meat stored for 3 or 6 days. Food poisoning bacteria were found in both untreated and morea-treated samples stored over 6 days. However, no such bacteria were detected in CA-treated samples. Also, CA-treated meat, cartilage, and skin showed low degrees of degeneration. Thus, CA treatment enhanced shelf-life and dombaeki quality by inhibiting microorganism growth and tissue breakdown during storage.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.306-314
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• 2003

Purpose : In our Previous study, we have shown the main cel1 death pattern Induced by irradiation or protein tyrosine kinase (PTK) inhibitors in K562 human myeiogenous leukemic cell line. Death of the cells treated with irradiation alone was characterized by mitotic catastrophe and typical radiation-induced apoptosis was accelerated by herblmycin A (HMA). Both types of cell death were inhibited by genistein. In this study, we investigated the effects of HMA and genistein on cell cycle regulation and its correlation with the alterations of radiation-induced cell death. Materials and Methods: K562 cells In exponential growth phase were used for this study. The cells were Irradiated with 10 Gy using 6 MeV Linac (200-300 cGy/min). Immediately after irradiation, cells were treated with 250 nM of HMA or 25 $\mu$N of genistein. The distributions of cell cycle, the expressions of cell cycle-related protein, the activities of cyclin-dependent kinase, and the yield of senescence and differentiation were analyzed. Results: X-irradiated cells were arrested In the G2 phase of the cell cycle but unlike the p53-positive cells, they were not able to sustain the cell cycle arrest. An accumulation of cells in G2 phase of first ceil-cycle post-treatment and an increase of cyclin Bl were correlated with spontaneous, premature, chromosome condensation and mitotic catastrophe. HMA induced rapid G2 checkpoint abrogation and concomitant p53-independent Gl accumulation. HMA-induced cell cycle modifications correlated with the increase of CDK2 kinase activity, the decrease of the expressions of cyclins I and A and of CDK2 kinase activity, and the enhancement of radiation-induced apoptosis. Genistein maintained cells that were arrested in the G2-phase, decreased the expressions of cyclin Bl and cdc25c and cdc25C kinase activity, increased the expression of pl6, and sustained senescence and megakaryocytic differentiation. Conclusion: The effects of HMA and genistein on the radiation-induced cell death of KS62 cells were closely related to the cell cycle regulatory activities. In this study, we present a unique and reproducible model in which for investigating the mechanisms of various, radiation-induced, cancer cell death patterns. Further evaluation by using this model will provide a potent target for a new strategy of radiotherapy.

• Journal of Ocean Engineering and Technology
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• v.25 no.6
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• pp.72-79
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• 2011

In this paper, the fatigue characteristics of shot peened A7075-T651 alloy were compared with those of the specimens without the shot peening. The multi-spindle and single-spindle rotating bending fatigue testing machines were employed for the evaluation. Shot peening (SP) with various pressure (5 psi, 10 psi, 15 psi, 25 psi and 35 psi) were used in this test. In order to investigate the effect of the applied pressure during the SP, we carried out the surface roughness test, compressive residual stress test, hardness test, tensile test, VHCF (Very high cycle fatigue) test and SEM observation. SP induced the formation of remarkable compressive residual stress from the surface to certain depth of sample by means of the plastic deformation. The surface hardness and the fatigue characteristics of the specimens were also modified by the SP. According to the S-N curves, fatigue lives of shot peended sample with 25 psi measures 50 times higher than that of the untreated sample. The fatigue lives of shot peened sample with 15 psi and 35 psi measure approximately 10 times higher than that of the untreated ones.

• Journal of Sport and Applied Science
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• v.2 no.1
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• pp.25-38
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• 2018

One of the largest and fastest growing segments of the tourism industry, sport tourism refers to travel to play sports, watch sports, or to visit a sport attraction including both competitive and non-competitive activities. In this respect, cycling can be considered as not only a form of physical exercise but also a form of tourism in which cycling is a usual tourism-related activity, heading to a particular destination. The purpose of this study is to examine how demographical differences of cycle tourists are related to the quality of their life. An online survey was conducted and data was analyzed using frequency, reliability, and one - way ANOVA using SPSS 22.0. First, we found that there was no significant difference on the quality of physical life based on demographical characteristics. Second, the analysis of the relationship between demographical characteristics and the quality of mental life showed that income level affects their quality of mental life. Third, the analysis of the relationship between socio demographic characteristics and the quality of social life showed that marital status affects the quality of social life. Fourth, no statistically significant difference was found between the demographical characteristics and the quality of environmental life. Further implications were discussed.

• The Journal of Society for e-Business Studies
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• v.25 no.3
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• pp.63-76
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• 2020

In the 21st century, informatization is playing a huge role in people's lives. Korea is experiencing the tremendous changes in social structure and lifestyle caused by informatization. This paper focuses on economic phenomena rather than discussion on social structure due to informatization. We check whether the Goodwin model, which can comprehensively express economic growth, economic cycle, and income distribution, is suitable for the Korean economy in the information age. This model is simulated by selecting a quantitative economic methodology that estimates coefficients from time series data of the Korean economy. The simulation results confirmed that the Goodwin model is suitable for analyzing functional income distribution in Korea.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.4
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• pp.208-215
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• 2013

An experimental study of an ORC (Organic Rankine Cycle) system has been performed for small-scale applications in the range of a few kW for low-grade-recovery heat sources. The ORC system was equipped with a scroll expander. Experimental tests were carried out using this system, and showed good performance and reliability for the small-scale system. The effects of various operating conditions were selected as the main parameters for the performance of ORC system, such as the expander speeds and mass flow rates of R-134a for expander inlet temperatures ranging from $100^{\circ}C$ to $190^{\circ}C$, as well as the thermal power, thermal efficiency, expansion efficiency, and volumetric efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.13-14
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• 2008

$Al_2O_3$ thin films were deposited on GaN (0001) by remote plasma atomic layer deposition (RPALD) technique using trimethylaluminum (TMA) precursor and oxygen radicals in the temperature range of 25 ~ $500^{\circ}C$. Growth rate per cycle was varied with substrate temperature from 1.8 $\breve{A}$/ cycle at $25^{\circ}C$ to 0.8 $\breve{A}$/cycle at $500^{\circ}C$. The chemical structure of the $Al_2O_3$ thin films was studied using X-ray photo electron spectroscopy (XPS). Excellent electrical properties of $Al_2O_3$/GaN MIS capacitor were grown at $300^{\circ}C$ process temperature.