• Journal of The Korean Association For Science Education
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• v.28 no.1
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• pp.24-31
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• 2008

This study aims at examining the concepts that apply in understanding the water cycle, to inquire into the concept related to the unit of earth structure that are taught in the Earth Science I. Analysis of word association, drawing and questionnaires showed that it was difficult for them to understand the water cycle within the earth system, and to put components into one integrated system together. In other words, it showed that they have a low standard of understanding in connection with the water cycle, that their understanding of water cycle are simple thoughts rather than systematic thought. It showed that they had an understanding of the atmosphere and hydrosphere to some extent, but they took no notice of the effect of the lithosphere or biosphere, nor do they have an understanding of its effect. Analysis of questionnaires showed that they have no well understanding of water cycle of cyclic nature, and that they have low standard of understanding of the components of water cycle.

• Journal of Sport and Applied Science
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• v.2 no.1
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• pp.1-10
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• 2018

Today, the population of cycle participants is consistently increasing. Cycling is becoming not only a form of physical exercise but also a form of tourism in which cycle activities are related to visiting a particular destination. With the perspective of participation sport tourism, the purpose of this study is to investigate how the level of cycle tourists' participation affects their quality of life. An online survey link was sent to cycle participants to collect data. Out of the total 337 respondents, a total of 226 samples were used for the final analysis, disregarding those that were found to be inadequate or unreliable. For data analysis, frequency analysis, reliability test, validity, correlations, and regressions were employed with SPSS 22.0. For our first result, we found that the level of cycle participation did not significantly affect the quality of physical life. Second, the level of cycle participation did not have significant effect on the quality of mental life. Third, the level of cycle participation behavior did not have a significant effect on the quality of social life. Fourth, the level of cycle participation behavior did not have a significant effect on the quality of environmental life. Conclusions and political implications are discussed.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.307-311
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• 2016

The aim of this study was to compare the appearance rate of vaginal cytology during estrous cycle in small pet bitches. A characteristic features of vaginal cytology during the estrous cycle were the high proportion of superficial cell in proestrus, anuclear cell in estrus, small intermediate cell in diestrus, and small intermediate cell in anestrus, respectively. There were no statistically significant differences of appearance rate of vaginal cytology among small pet bitches in the each phase of estrous cycle. These results indicated that the vaginal cytology was useful method for estimating estrous cycle and optimal breeding time in small pet bitches.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1312-1314
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• 1998

SOFC system is often subject to thermal cycle condition during normal start/stop, shutdown, and emergence state. Under the thermal cycle condition of heating and cooling, the SOFC components expand or shrink, which produces thermal stress and thermal shock. The SOFC performance is degraded by the thermal factors. To protect SOFC system from the thermal degradation, the optimum thermal condition must be clarified. In this study, to examine the thermal cycle characteristics, we fabricated single cells of planar SOFC with an area of $5{\times}5cm$. The electrolyte and PEN were tested under thermal cycle conditions in the range of$ 2-8^{\circ}C/min$. After thermal cycle test. crack creation of the components were examined using ultraviolet apparatus. No crack in the electrolyte and PEN were observed. The single cell system with alumina frame were also tested under thermal cycle conditions of 2, 3, $4^{\circ}C/min$. The single cell was fractured at the thermal cycle of 3 and $4^{\circ}C/min$ and the optimum condition of the thermal cycle to be found below $2^{\circ}C/min$.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.10
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• pp.399-409
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• 2006

This paper presents a novel method for satisfying the thermal comfort of indoor environment and reducing the summer peak demand power by minimizing the power consumption for an Air-conditioner within a space. Korea Electric Power Corporation (KEPCO) use the fixed duty cycle control method regardless of the indoor thermal environment. However, this method has disadvantages that energy saving depends on the set-point value of the Air-Conditioner and direct load control (DLC) has no net effects on Air-conditioners if the appliance has a lower operating cycle than the fixed duty cycle. In this paper, the variable duty cycle control method is proposed in order to compensate the weakness of conventional fixed duty cycle control method and improve the satisfaction of residents and the reduction of peak demand. The proposed method estimates the predict mean vote (PMV) at the next step with predicted temperature and humidity using the back propagation neural network model. It is possible to reduce the energy consumption by maintaining the Air-conditioner's OFF state when the PMV lies in the thermal comfort range. To verify the effectiveness of the proposed variable duty cycle control method, the case study is performed using the historical data on Sep. 7th, 2001 acquired at a classroom in Seoul and the obtained results are compared with the fixed duty cycle control method.

• Culinary science and hospitality research
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• v.2
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• pp.59-87
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• 1996

This study has been done by giving the guide when development of menu or doing marketing strategy in Hotel Restaurant. All products and service has a regular course from induction in market to disappear, so it shall be come out Products Life Cycle theory. In eating business, under the tendency and existing cycle to change menu by taste of customers, liking variation, change of periodic status (environment), MLC(Menu Life Cycle) shall be advised by application PLC(Products Life Cycle) in the process of induction of some menu first and spreading the same business field and then deletion (disappearance) from menu because of no popular. In Emergence Stage, it shall be tried to inform new menu through Cooking Contest, presentation of new menu, free sampling party and others. In Growth Stage, it shall be changed package menu or set menu. In Maturity Stage, it shall be provided complimentary ticket, gift coupon or discount for the customers with some degree of selling record in order to increase using frequency and selling amount after insure new customers. In Decline Stage, it shall be groped for entry underdeveloped country or less advance nation, but there is no possibility to devote in enterprise, it shall be planned substitute menu development in order to withdraw. By inducting MLC concept, it shall be provided the available informations such as“how could some menu be circulate in some restaurant”“Accordingly do strengthen promotion activities or go to low developed area or overseas, or delete it from menuitems and so on”. In the time of decline some menu, it is judged to the time of plan(preparation) of new menu development. In the broad view, when consideration of the concept of menu life cycle, it shall be possible to know which menu is decayed and which menu is developed newly or grown-up, so it shall be provided the important information to estimate the tendency of changing menu and set-up a menu development plan.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.195-199
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• 2007

Inositol hexaphosphate ($IP_6$) is a major constituent of most cereals, legumes, nuts, oil seeds and soybean. Previous studies reported the anticancer effect of $IP_6$ and suggested that co-treatment of $IP_6$ with inositol may enhance anticancer effect of $IP_6$. Although the anticancer effect of $IP_6$ has been intensively studied, the combinational effect of $IP_6$ and inositol and involved mechanisms are not well understood so far. In the present study, we investigated the effect of $IP_6$ and myo-inositol (MI) on cell cycle regulation and apoptosis using PC3 prostate cancer cell lines. When cell, were co-treated with $IP_6$ and MI, the extent of cell growth inhibition was significantly increased than that by $IP_6$ alone. To identify the effect of $IP_6$ and MI on apoptosis, the activity of caspase-3 was measured. The caspase-3 activity was significantly increased when cells were treated with either $IP_6$ alone or both $IP_6$ and MI, with no significant enhancement by co-treatment. To investigate the effect of $IP_6$ and MI of cell cycle arrest, we measured p21 mRNA expression in PC3 cells and observed significant increase in p21 mRNA by $IP_6$. But synergistic regulation by co-treatment with $IP_6$ and MI was not observed. In addition, there was no significant effect by co-treatment compared to $IP_6$ treatment on the regulation of cell cycle progression although $IP_6$ significantly changed cell cycle distribution in the presence of MI or not. Therefore, these findings support that $IP_6$ has anticancer function by induction of apoptosis and regulation of cell cycle. However, synergistic effect by MI on cell cycle regulation and apoptosis was not observed in PC3 prostate cancer cells.

• Korean Journal of Animal Reproduction
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• v.13 no.3
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• pp.179-187
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• 1989

The experiment was carried out to study the profile of uterine specific protein during early pregnancy in sows and to test it's immunosuppressive activity. Uterine protein samples were obtained by flushing the uterine horn on Day 3, 6, 9, 12 and 15 of the estrous cycle and the pregnancy respectively and the protein concentration of each sample was determined. The change of uterine protein was examined by sodium dodecyl sulfate(SDS)-PAGE. The immunosuppressive activity of uterine secretory protein was investigated according to the lymphocyte blastogenesis response to mitogen. The results of this experiment are summarized as follows ; 1. The uterine protein during estrous cycle and early pregnancy was relatively constant up to Day 9, but increased on Day 12. Maxium total protein values were found on Day 15. The concentration of serum proteins were about 82-95 mg during estrous cycle, but decreased to about 70-82 mg during early pregnancy. 2. The proteins components similar electrophoretic patterns(PAGE) that were no differences (band ; a, b, c, d, e, f, g, I) on Days 3, 6 and 9 of the estrous cycle and pregnancy. But there were more 2 bands specifically on Day 12 of the pregnancy and on Day 15 of estrous cycle and showed more 4 bands on Day 15 of early pregnancy. They seemed to be acidoprotein and their average molecular weight were 38,000, 22,300 and 12,600. 3. When uterine protein were added 500$\mu\textrm{g}$/ml, there was no immunosuppresive activity on Day 3 of estrous cycle and lymphocyte blastogenesis was slightly suppressed on Day 3 of pregnancy. The immunosuppressive activity on Day 9 of estrous cycle and pregnancy appeared in 500$\mu\textrm{g}$/ml and 150$\mu\textrm{g}$/ml, respectively the uterine protein on Day 12 and 15 showed immunosuppresive activity, which at the level of 150$\mu\textrm{g}$/ml during non-pregnancy and at the level of 100 to 125$\mu\textrm{g}$/ml during early pregnancy, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.745-756
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• 2013

The purpose of this study is to evaluate representativeness of fuel-based emission factors. Twelve light-duty diesel vehicles which meet Euro-3 to 5 legislative emission limits were selected for emission tests. Second-by-second modal emission rates of vehicles were measured on a standard laboratory chassis dynamometer system. An off-cycle driving cycle was developed as a representative Korean real-world on-road driving cycle. Fuel-based emission factors were developed for short trip segments that involved in the selected driving cycle. Each segment was defined to have unit travel distance, which is 1 km, and characterized by its average speed and Relative Positive Acceleration (RPA). Fuel-based $NO_x$ emission factors demonstrate relatively good representativeness in terms of vehicle operation conditions. $NO_x$ emission factors are estimated to be within ${\pm}20%$ of area-wide emission factor under more than 40% of total driving situations. This result implies that the fuel-based $NO_x$ emission factor could be practically implemented into the on-road emission management strategies, such as a remote sensing device (RSD). High emitting vehicles as well as high emitting operating conditions heavily affect on the mean values and distributions of CO and THC emission factors. Few high emitting conditions are pulling up the mean value and biasing the distributions, which weaken representativeness of fuel-based CO and THC emission factors.

• Korean Journal of Veterinary Research
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• v.55 no.2
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• pp.111-116
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• 2015

In the present study, the effects of different photoperiods on stress, immunity, and hematological parameters in ICR mice were evaluated. Fifty male ICR mice 7 weeks old (body weight, $27.3{\pm}2.5g$) were divided into five groups: DP-0 (0/24-h light/dark cycle), DP-6 (6/18-h light/dark cycle), DP-12 (12/12-h light/dark cycle), DP-18 (18/6-h light/dark cycle), and DP-24 (24/0-h light/dark cycle). During the experimental period, no significant differences in body weight or feed intake were observed between the groups. Hematological analysis revealed that white blood cell, red blood cell, and hemoglobin values for the DP-0 group were significantly different compared to those of the other groups. After 28 days, no significant difference in serum cortisol concentration was observed among the groups, but serum cortisol levels increased in a light exposure-dependent manner. Total serum immunoglobulin G (IgG) concentrations of the DP-0 and PD-6 groups were significantly increased compared to those of the other groups (p < 0.05), and serum total IgG levels decreased in a light exposure-dependent manner. Results of the present study indicated that various photoperiods affect hematological parameters and total serum IgG levels in ICR mice while having no significant effects on body weight, feed intake, or cortisol levels.