• Korean Journal of Child Studies
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• v.33 no.3
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• pp.131-148
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• 2012

This study examines the scientific concept development of young children in terms of the day-night cycle. The subjects consisted of 180 three-, four-, and five-year-old children from two kindergartens and one children's center located in Seoul and Jeju. Individual interviews were conducted to collect verbal and pictorial responses on the day-night cycle. The scientific concepts on the day-night cycle are classified five stages including : no recognition, egocentric concept, initial mental models, synthetic mental models, and scientific mental models. Using two-way ANOVA, scores for the types of concept on the day-night cycles were then analyzed according to both the ages and genders of the children. The results reveal the existence of significant differences in terms of the types of concept of young children according to age. Most three-year-olds children had no recognition. Most three, four, and five-year-old children revealed egocentric concepts. Four-year-old children revealed that were in the initial stages of experiencing the mental models and synthetic mental models of the day-night cycle. Five-year-old children revealed that they were in the early stages of experiencing the initial, synthetic, scientific mental models of the day-night cycle. The results suggest appropriate ways of science education for young children based on the development of scientific concepts of the day-night cycle.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.217-223
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• 1997

This study was performed to determine if women with day 3 serum inhibin-B concentrations <45pg/ml (conversion factor to SI unit, 1.00) demonstrate a poor response to ovulation induction and assisted reproductive technology outcome to women with inhibin-B${\ge}45pg$/ml, independant of day 3 FSH, E2 and patient age. From Jan 1996 to Dec 1996, 16 volunteers patients who underwent 25 IVF cycles with luteal phase GnRH agonist suppression and HMG stimulation were allocated to the study group. We evaluated day 3 serum inhibin-B, FSH, E2, peak E2, cancellation rate per initiated cycle (%) and clinical pregnancy rate per initiated cycle (%) according to the above two groups and independent of patient age, day 3 FSH, day 3 E2 and all of above combined. Women with day 3 serum inhibin-B${\ge}45pg$/ml demonstrated higher average day 3 inhibin-B level, clinical pregnancy rate per initiated cycle ($20.3{\pm}2.5$ pg/ml vs $80.9{\pm}5.0$ pg/ml, p<0.05; 24.8% vs 8.5%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle ($6.9{\pm}0.3$ mIU/ml vs $8.5{\pm}0.5$ mIU/ml, p<0.05; 1.5% vs 9.0%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml and age<40 year demonstrated higher pregnancy rate per initiated cycle (28.2% vs 7.4%, p<0.05) and lows. day 3 FSH level, cancellation rate per initiated cycle ($6.9{\pm}0.5$ mIU/ml vs $8.2{\pm}0.7$ mIU/ml, p<0.05; 1.0% vs 9.0%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml and day 3 FSH<15mIU/ml demonstrated higher pregnancy rate per initiated cycle (33.5% vs 9.5%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle ($7.7{\pm}0.2$ mIU/ml vs $8.5{\pm}0.5$ mIU/ml, p<0.05; 1.5% vs 10.0%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml and day 3 E2<50pg/ml demonstrated higher pregnancy rate per initiated cycle (30.0% vs 9.5%, p<0.05) and lower cancellation rate per initiated cycle (1.5% vs 9.5%, p<0.05). Women with day 3 serum inhibin${\ge}45pg$/ml, age<40 year, day 3 FSH<15mIU/ml and day 3 E2<50pg/ml demonstrated higher pregnancy rate per initiated cycle (30.0% vs 10.8%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle ($6.8{\pm}0.6$ mIU/ml vs $8.4{\pm}0.9$ mIU/ml, p<0.05; 1.5% vs 7.8%, p<0.05). Therefore women with low day 3 serum inhibin-B concentrations demonstrate a poorer response to ovulation induction and are less likely to conceive a clinical pregnancy though ART relative to women with high day 3 inhibin-B and day 3 serum inhibin-B, in addition to a day 3 FSH, E2 and patient age, appears helpful in prediction in IVF-ET outcome.

• 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 of Forest Science
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• v.101 no.3
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• pp.344-355
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• 2012

This study was conducted to analyze on the operational time and productivities of logging operations in whole-tree logging operation system by tower-yarder and swing-yarder, and in cut-to-length logging operation system by excavator with grapple in order to establish the efficient logging operation system and to spread logging operation technique. In the analysis of operational time, in case of whole-tree logging operation system, the felling time was 46.6 sec/cycle by chain saw, the yarding time was 480.6 sec/cycle by tower-yarder, the yarding time was 287.4 sec/cycle by swing-yarder and the bucking time was 155.14 sec/cycle by chain saw. In case of the cut-to-length logging operation system, the felling and bucking time was 225.65 sec/cycle by chain saw, the cut-to-length extraction time was 4,972 sec/cycle by excavator with grapple, the branches and leaves extraction time was 3,143 sec/cycle by excavator with grapple. The forwarding time was 4,688 sec/cycle by wheel type mini-forwarder, the forwarding time was 2,118 sec/cycle by excavator with grapple and small forwarding vehicle. In the analysis of operational productivities, in case of whole-tree logging operation system, the average felling performance was $57.89m^3/day$ by chain saw, the average yarding performance was $20.3m^3/day$ by tower-yarder, $31.55m^3/day$ by swing-yarder respectively, the average bucking performance was $20.3m^3/day$ by chain saw. In case of the cut-to-length logging operation system, the average felling and bucking performance was $11.96m^3/day$ by chain saw, the average cut-to-length extraction performance was $34.75m^3/day$ by excavator with grapple, the average branches and leaves extraction performance was $37.66m^3/day$ by excavator with grapple, the average length of operation road construction was 73.8 m/day by excavator with grapple. The average forwarding performance by wheel type mini-forwarder and the average forwarding performance by excavator with grapple and small forwarding vehicle was $15.73m^3/day$ and $65.03m^3/day$, respectively.

• Journal of Veterinary Clinics
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• v.13 no.2
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• pp.114-122
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• 1996

The aim of this study was to assess the precision of the estimates of the time of estrous cycle, optimal breeding and ovulation derived by vaginal cytology. The thirteen Korea Jin-do dogs were examined the vaginal cytology, plasma estradiol-17$$\beta $ and progesterone assay during the estrous cycle. Day 0 was the day of the first male acceptance. The main change of vaginal cytology during the estrous cycle was the high proportion of anuclear cell and erythrocyte in proestrus, superficial cell, anuclear cell and erythrocyte in estrus, parabasal cell, large intermediate cell and leukocytes in diestrus, and parabasal cell and small intermediate cell in anestrus, respectively. These data indicated that vaginal cytology was reliable method for estimating estrous cycle in Korea Jin-do dogs. In the cell indices during estrus the maximum eosinoghilic index was $92.0{\pm}$2.6 (Mean{\pm} SEM$)% at Day 2 and the maximum cornification indez was $96.0{\pm}1.3%$ at Day 2, respectively. The eosinothilic indez and cornification indez of up to 70% were found at Day -1 to Day 5 and Day -6 to Day 8, and up to 80% at Day 1 to Day 4 and Day -4 to Day 6, respectively. From these data it was presumed that eosinophilic index was more reliable index for monitoring optimal breeding time than cornification indexm because eosinophilic index peak period was shorter than cornification indeX peak period and Day 2 was the day of ovulation. Therefore, optimal breeding time was the eosinophilic index peak period, more than 80% of eosinoghilic index. The $estradiol-17{\beta}$ peak, with 3 days delayed when progesterone concentration was $4.5{\pm}0.5 ng/ml$. These data estimated that the ovulation time was the day of eosinophilic index peak, Day 2. breeding time and pvulation time in Korea Jin-do dogs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.115-118
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• 2007

A tall building construction is needed to reduce the construction duration for project profitability. Reducing the cycle time of typical floor in the structural frame work which have the largest duration in the whole construction, greatly affects construction duration. Nowadays, some projects are accomplished in the 3 day cycle. In order to accomplish efficiently 3 day cycle, productivity information of similar projects is supported. Therefore, this study proposed labor productivity and application by slab formwork to construct by the 3 day cycle. In order to perform an analysis, we selected 3 cases and analyzed the labor productivity on the basis of the amount of slab forms, labors, and durations. Then, we performed the questionnaire to analyze the application by formwork of tall building construction engineers. This study will contribute to establish a reasonable scheduling in structural frame work of a new similar project.

• Journal of Embryo Transfer
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• v.4 no.1
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• pp.41-45
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• 1989

Total thirty of flushing were attempted on day 4 to 15 of estrus cycle with S heifers and 9 cows by nonsurgical method. The flushed or recovered rate among flushings was 86.7% (26/30) or 88.5% (23/26), respectively. There was no difference in the recovered rate between heifers (85.7%,6/7) and cows (89.5%, 17119). The embryo was recovered on day 4 to 15 of estrus cycle from the donors in natural heat without any technical difficulties.The I2FG Foley catheter used for pubertal heifers had sometimes plug in it with uterine mucus during flushing of uterine horn. But the problem could be overcomed by pumping the catherter with fluthing solution or by changing the catheter. Three normal embryos were recovered from 3 pubertal (10-11 month old) heifers. The rate of normal and abnormal eggs was 60.9% (14123) and 39.1% (9/23), respectively. The abnormal eggs were on degenerating except one unfertilized egg and were mostly recovered from heifers or cows flushed consecutively during the estrus cycle. The developmental states of normal embryos were l6-cells on day 5, 32-cells on day 6, compacted-morula on day 7, early-to expanded-blastocyst on day 8-to 9, and hatching-to hatched-blastocyst on day 10 to 11 of estrus cycle. The stage of embryos on day 8 to 10 showed varities among donors. On day 8 to 9 of estrus cycle hatching-blas tocyst was recovered from some donors.

• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.27.1-27.12
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• 2022

Background: Shift work that interferes with normal sleep patterns, is known to be a cause of sleep disturbance and has been studied through various occupational groups. However, it is not known which shift type is better for sleep health. Methods: This study included 568 firefighters. Sleep quality was evaluated using Pittsburgh Sleep Quality Index. Sleep quality was categorized into 2 groups; good quality (≤ 5 points) and poor quality (≥ 6 points). Demographic variables, depression, anxiety, type of shift, and job were collected by self-reported questionnaires. The χ² test, t-test, and multiple logistic regression analysis were used to evaluate the effect of shift type on the sleep quality of firefighters. Results: Three hundred thirty-seven firefighters (59.3%) have poor sleep quality. Compared to day workers, the odds ratios (ORs) of poor sleep quality were 2.169 (95% confidence interval: 1.137-4.134) in 6-day cycle, 2.161 (1.150-4.062) in 9-day cycle, 1.805 (1.087-2.997) in 21-day cycle, and 1.485 (0.718-3.069) in 3-day cycle. The ORs of poor sleep quality were 1.697(1.021-2.823) in fire suppression and 2.325 (1.213-4.455) in emergency medical service compared to administration. Conclusions: All shift work type except for the 3-day cycle was associated with poor sleep quality compared to day work.

• Korean Journal of Animal Reproduction
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• v.16 no.2
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• pp.133-139
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• 1992

The study was conducted to find out the changes of progesterone and 20$\alpha$-dihydroprogesterone (20$\alpha$-OHP) levels during the oestrous cycle in Korean native goats. 4 cyclic goats were offered for this experiment. Blood samples were taken from jugular vein on day 0, 1, 3, 5, 7, 9, 11, 13, 15, 17 and 19 during the oestrous cycle, then the next oestrous day. The serum levels of progesterone and 20$\alpha$-OHP were measured by radioimmunoassay. The progesterone concentration in seurm of the cyclic goats was 0.29$\pm$0.06ng/ml on the first day of oestrous (day 0), increased to 5.29$\pm$0.73ng/ml on day 9, reached to a peak level of 5.73$\pm$0.61ng/ml on day 13, and thereafter decreased to 0.35$\pm$0.30ng/ml on day 1. The serum level of 20$\alpha$-OHP during the oestrous cycle was 0.42$\pm$0.33ng/ml on day 0 and then decreased to 0.28$\pm$0.01ng/ml on day 5. This basal level was maintained until day 13, increased gradually, and reached a peak level of 0.62$\pm$0.05ng/ml on day 19. From the above results, it was suggested that the enzyme 20$\alpha$-hydroxysteroid dehydrogenase(20$\alpha$-HSD) catalyzing the conversion of progesterone to a biologically inactive steroid, 20$\alpha$-OHP, should be active in the luteal cells during the oestrous cycle in Korean native goats.

• Fisheries and Aquatic Sciences
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• v.22 no.1
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• pp.4.1-4.10
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• 2019

Russian sturgeon (Acipenser gueldenstaedtii) is commercially important in Korea because its caviar is highly prized. Although the early ontogeny of the species has been described, behavioral modifications in response to various light intensities or diel photoperiodicity patterns have not been studied extensively. The objective of the present study was to examine the behavioral characteristics of hatchery-produced A. gueldenstaedtii prelarvae over a diel photoperiodic cycle. During a diel light cycle comprising 16 h of daylight (450 lx), 4 h of dim light (10 lx), and 4 h of darkness (< 1 lx), newly hatched A. gueldenstaedtii prelarvae exhibited negative phototaxis in daylight (day 0-day 2), and this early behavior was not significantly affected by changes of light intensities. Rheotactic and non-rheotactic aggregation into schools was typical between days 3 and 6. Under the diel light cycle conditions described, rheotaxis was not influenced by environmental light intensity as much as non-rheotactic schooling behavior. Post-schooling behavior, which progressed from day 7 to day 8, did not change significantly during the diel light cycle. The data from the present study could be of practical value in developing a visual guide for assessing the fitness and quality of Russian sturgeon prelarvae under diel light cycle conditions in hatcheries.