• Journal of Applied Reliability
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• v.17 no.4
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• pp.305-315
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• 2017

Purpose: The purpose of this research is to propose procedure and methodology for developing failure rate databook which is suitable for Korean operation environment. Methods: To this end, we investigate failure databooks used in foreign countries and study the procedure and methodology for collecting failure data, organizing the data, estimating failure rate and summarizing results. Results: We develop the procedure of development of failure databook, the items for data collection, database schema of part details and part summary and contents of failure databook by considering the application environment in Korea. Conclusion: The results of our research could be utilized for the development of Korean failure rate databook and research of reliability prediction model and could ultimately contribute to improve the accuracy of reliability prediction.

• Journal of Embryo Transfer
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• v.26 no.2
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• pp.117-122
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• 2011

In this study, we examined the effectiveness of in vitro fertilization of porcine immature oocytes on the embryo development of blastocysts or hatched blastocysts and the number of cells according to the in vitro fertilization conditions. In the in vitro fertilization of in vitro matured porcine oocytes, there were no significant differences between treatment groups regarding fertilization rate, blastocyst rate, and embryo development of hatched blastocysts according to the storage periods of liquid sperm of 24, 48, and 72 hours. The embryo development rate of hatched blastocysts after the fertilization according to different spermatozoa concentrations ($0.4{\times}10^5$, $1.2{\times}10^5$, and $3.6{\times}10^5$ cells/ml) showed the highest rate in the group with a spermatozoa concentration of $1.2{\times}10^5$ cells/ml; in particular, this rate was significantly higher than that in the $0.4{\times}10^5$ cells/ml group (p<0.05). The total number of blastocysts cells as well as trophectoderms (TE) that developed in each treatment group were also significantly higher in the $1.2{\times}10^5$ cells/ml group than in any other groups (p<0.05). In contrast, the embryo development rate of blastocysts according to different co-incubation periods of sperm and oocyte (1, 3, and 6 hr) was high in the 6-hour group; in particular, the rate was significantly higher than that of the I-hour group (p<0.05). Furthermore, the total number of oocytes cells and TEs that developed was significantly higher in the 6-hour group than any other group (p<0.05). In this study, the most effective treatment conditions for porcine embryo development and high cell number were found to be as follows: a sperm storage period of less than 72 hours, a spermatozoa concentration of $1.2{\times}10^5$ cells/ml, and a 6-hour co-incubation period for sperm and ooocyte.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.127-132
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• 2016

This study evaluated the economic value of the development of a new variety of Citrus unshiu using the income approach, Net Present Value (NPV), Internal Rate of Return (IRR), and Benefit/Cost (B/C) ratio. The new variety of Citrus unshiu was developed by the national institute of horticultural and herbal science in Korea, rural development administration. The technological evaluation of the development of a new variety of Citrus unshiu can be used to improve the efficiency and practicality of the development of a new variety of citrus. From the research results, the technological value of development of a new variety of Citrus unshui was evaluated at 109,455(discount rate=8%, minimum), 195,040(discount rate=4%, maximum), and 145,375(discount rate=6%, average) million won. The IRR was 51.4%, which was greater than the discount rate(4~8%). The NPV was evaluated at 145.3 billion won(discount rate=6%, average), 195.0 billion won(discount rate=4%, maximum) and 109.4 billion won(discount rate=8%, minimum), all of which were greater than 0. The B/C ratio was evaluated at 60.9(discount rate=6%, average), 81.3(discount rate=4%, maximum) and 46.1(discount rate=8%, minimum), all of which were greater than 1. Therefore, the economic validity of the development of a new variety of Citrus unshiu was identified by this technological evaluation.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1117-1123
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• 2009

This study investigated the effects of IGF-I and EGF on the development of blastocysts or hatched blastocysts during the in vitro culture of embryos from immature porcine oocytes. After the in vitro maturation and fertilization of cumulus-oocyte complexes (COCs) and their culture in vitro in PZM3 medium, we examined the embryo development rate for 168 h. When different concentrations of IGF-I (0, 1, 10, 20 ng/ml) were supplemented to fertilized porcine embryos in vitro, there were no significant differences in cleavage rate, blastocyst development rate or blastocyst hatching rate among the treated groups. On the other hand, when different concentrations of EGF (0, 1, 10, 20 ng/ml) were supplemented to the in vitro culture medium, blastocyst development rate was highest in the group in which EGF was not supplemented and, specifically, it was higher than in the 20 ng/ml treatment group (p<0.05). When 10 ng/ml IGF-I and 1 ng/ml EGF were supplemented separately or simultaneously, there were no significant differences among the treated groups in blastocyst hatching rate and the number of cells in each condition. This study demonstrated that the addition of IGF-I and EGF into PZM3 medium did not enhance development of the blastocyst stage and total cell number in blastocysts.

• Korean Journal of Animal Reproduction
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• v.14 no.1
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• pp.9-16
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• 1990

This study was carried out in order to investigate effects of cryoprotectant concentration and equilibration time on survival of ultrarapidly frozen 2-cell mouse embryos. Mouse 2-cell embryos, following dehydration by exposure to DMSO and sucrose, were directly immersed into liquid nitrogen and thawed in 37$^{\circ}C$ water. Viability was defined by development rate to the blastocyst stage after in vitro culture for 72 hours. The results are summarized as follows ; 1. When 0.25M of sucrose was added into the freezing medium at various concentrations of DMSO and dilution medium, higher development rate of embryo was obtained in 3.0M DMSO concentrations (82.6%). However, when sucrose concentraitons of 0.25 and 0.5 M were added to the freezing medium with 3.0 M DMSO and dilution medium, development rate of embryos were 81.7% and 24.1%, respectively. 2. In the equilibration time at room temperature, higher development rate was attained after short period of time (2.5min) in 3.0 M DMSO＋0.25 M sucrose (85.9%). 3. The development rate of embryos at in vitro 2-cell, in vitro 2-cell, solution control and untreated control was 84.6%, 90.9%, 89.9%,, and 89.7%, respectively.

• Korean Journal of Veterinary Research
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• v.20 no.1
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• pp.59-64
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• 1980

Incidence of avian infectious diseases in breeder chickens was followed serologically. Serum samples were collected during the period of 1978~1979 from breeders throughout country and tested for the presence of antibodies against Salmonella pullorum(SP), Mycoplasma gallisepticum(MG), Avian Infectious Bronchitis virus(AIBV), Infectious Bursal Disease virus(IBDV) and Egg Drop Syndrome Virus(EDS). The tests used serum plate agglutination for SP and MG, immuno-diffusion for AIBV and IBDV and hemagglutination-inhibition test for EDS virus. The results are summarized as follows: 1. Individuals and Hocks incidence rate of Avian Infectious Bronchitis virus were 16.9% and 55.3%. 2. Individuals and Hocks incidence rate of Infectious Bursal Disease virus were 50.1% and 66.4%. 3. Individuals and Hocks incidence rate of sal. pullorum were 17.2% and 65.9%. 4. Individuals and flocks incidence rate of M. gallisepticum were 36.2% and 63.2%. 5. Individuals and flocks incidence rate of Egg Drop Syndrome (BC 14) virus were 14.1% and 46.3%.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.395-406
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• 2023

Ten women in their 20s and 10 women in their 50s were selected to investigate the effect of an elastic band exercise program for 8 weeks according to age on women's knee speed expression rate and balance. Knee isokinetic muscle strength measurement, single-legged standing with eyes closed, and YBT were performed 1 week before and after the exercise program. The measured data were analyzed through a mixed design two-way ANOVA, and if there was a significant difference, post hoc verification was performed using the bonferoni method. In our study, as a result of an 8-week elastic band exercise program, there was no difference in the speed development rate according to the measurement period, and the speed development rate according to age was found to be higher in people in their 50s than in their 20s. In our study, there was no difference in balance ability depending on the measurement period, and there was also no difference in balance ability depending on age. Discussing the results of our study, we found that 8 weeks of elastic band exercise cannot bring about significant changes in speed development ability and balance ability, which become more accurate with age.

• Computers and Concrete
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• v.33 no.5
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• pp.519-533
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• 2024

Many materials including cementitious concrete-type materials undergo material property changes during high-rate loading. There is a wealth of research regarding this phenomenon for concrete in compression and tension. However, there is minimal knowledge about how mortar material used in concrete masonry unit (CMU) construction behaves in high-rate shear loading. A series of experiments was conducted to examine the bond strength of mortar bonded to CMU units under high-rate shear loading. A novel experimental setup using a shock tube and dynamic ram were used to load specially constructed shear triplets in a double lap shear configuration with no pre-compression. The Finite Element Method was leveraged in conjunction with data from the experimental investigation to establish if the shear bond between concrete masonry units and mortar exhibits any rate dependency. An increase in shear bond strength was observed when loaded at a high strain rate. This data indicates that the CMU-mortar bond exhibits a rate dependent strength change and illustrates the need for further study of the CMU-mortar interface characteristics at high strain rates.

• Journal of Microbiology and Biotechnology
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• v.18 no.8
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• pp.1377-1385
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• 2008

The uracil-sensing domain in archaeal family B-type DNA polymerases recognizes pro-mutagenic uracils in the DNA template, leading to stalling of DNA polymerases. Here, we describe our new findings regarding the molecular, mechanism underpinning the stalling of polymerases. We observed that two successive deaminated bases were required to stall TNA1 and KOD1 DNA polymerases, whereas a single deaminated base was enough for stalling Pfu DNA polymerase, in spite of the virtually identical uracil-sensing domains. TNA1 and KOD1 DNA polymerases have a much higher extension rate than Pfu DNA polymerase; decreasing the extension rate resulted in stalling by TNA1 and KOD1 DNA polymerases at a single deaminated base. These results strongly suggest that these polymerases require two factors to stop DNA polymerization at a single deaminated base: the presence of the uracil-sensing domain and a relatively slow extension rate.

• Mycobiology
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• v.39 no.3
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• pp.158-163
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• 2011

This study was conducted to confirm the possible use of female Yangwonjam as a host for synnemata production of Isaria tenuipes in eight local areas in Korea. Silkworm pupation rate, infection rate and synnemata characteristics of I. tenuipes were examined. Normal silkworms had a higher pupation rate than silkworms inoculated with I. tenuipes. The pupae survival percentage of normal silkworm in cocoons was 92.5~97.6%, whereas it ranged from 91.1~95.6% in silkworms sprayed with I. tenuipes. Female Yangwonjam showed the highest survival percentage at 97.6% among the silkworm varieties tested. I. tenuipes infection rate of larvae of 5th instar newly-exuviated silkworms was 89.2~90.7% in the spring rearing season and 98.2~99.3% in the autumn rearing season. Synnemata production of I. tenuipes was excellent in female Yangwonjam with an incidence rate of 98.0% followed by male Yangwonjam (94.1%) and Baegokjam (93.3%) in the spring rearing season. Synnemata living weight ranged from 1.44~0.94 g in the spring rearing season. The female Yangwonjam had the heaviest synnemata weight (1.44 g) in the spring rearing season. The synnemata of I. tenuipes produced on pupae were white or milky-white in color, and were similar in shape and color to wild synnemata collected in Korea.