• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.125-125
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• 2017

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.249-258
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• 2003

The aim of this study was to investigate the effects of different hexoses in medium with IGF-I and/or EGF on in vitro development of porcine embryos. In first experiment, when the embryos were cultured in medium with concentrations of 5 ng/ml IGF-I and 10 ng/ml EGF, the morula and blastocyst rates were higher than in another culture conditions (P<0.05). In second experiment, the effect of IGF-I in medium with different hexoses during the embryo culture was examined. The higher cleavage rates were obtained in medium with glucose and IGF-I (P<0.05). However, the higher proportion of embryos developed to morula and blastocyst stages in medium with IGF-I were obtained than in medium without IGF-I in medium with glucose, mannose and galactose. In third experiment, the effect of EGF on in vitro development of porcine embryos in medium with different hexoses were examined. In the culture medium was supplemented with glucose, the higher proportions (P<0.05) of embryos developed to molura and blastocyst stages were obtained in medium with that than without EGF. However, the proportions of embryos developed to blastocyst stage were not significantly different between with and without of EGF in medium with different hexoses. In firth experiment, the effects of presence of IGF-I and EGF in medium with different hexoses on in vitro development of porcine embryos were examined. When culture medium was supplemented with IGF-I and EGF, the higher proportions of oocytes cleaved and developed to 8-cell stage were obtained in medium with glucose than mannose, galactose and fructose (P<0.05). These results show that glucose and growth factors, supported the development in vitro of porcine embryos, especially with greater embryo cleavage and development in medium with glucose added to media with IGF-I and/or EGF.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.32-37
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• 2000

The in vitro culture of rice panicles is a culturing technique only panicle without other organs in culture solution containing organic substance, so that would be useful to study how assimilate supply affects grain development and maturation. To find the optimum stage for in vitro culture, rice panicles grown in greenhouse were sampled periodically after anthesis and cultured in nutrient medium. The panicles older than 1 weeks after anthesis had produced normal grains. Grain-filling was apparently dependent upon sucrose concentration (8-12 %) in medium, but not affected by nitrogen concentration supplied with glutamine. As far as rice panicle was supplied with sucrose and N in nutrient medium, grains continued accumulation of dry matter and maturation regardless to light condition. Considerably, grain-filling was improved when panicles were positioned horizontally inside flask, so that each grain was partially submerged to nutrient medium.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.206-207
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• 2022

Currently, safety accidents in construction area are managed regardless of the size. Therefore, the objective of this study is to conduct for developing the quantitative risk assessment according to large and small and medium-sized construction sites. The scope of this study is limited to the fall accidents which is the biggest accidents in the construction sites. the regression analysis was conducted based on the collected data. As a result, it was confirmed that there was a statistically significant difference between larce and small and medium-sized construction sites. This study is expected to be used as basic data for research on the development of a risk quantitative model for small and medium-sized construction sites in the future.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.39-46
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• 2000

Objective: A number of studies to improve in vitro culture conditions have been tried over past ten years by using co-culture system with helper somatic cells. However, the mechanism of coculture is poorly understood. This study was designed to understand the mechanism for the mode of actual action of co-culture using co-culture system of ICR strain's 1-cell embryos with human oviduct epithelial cells by examining the effect of conditioned medium and contactless coculture using a cell culture insert on the embryo development and by measuring the level of superoxide anion from conditioned medium after co-culture. Methods: ICR strain's zygote embryos were cultured in medium alone (control), coculture, conditioned medium, or contactless coculture system for 6 days. Conditioned media (CM) were prepared as following 5 groups. All CM were collected after culturing oviduct cells for 2 days. CM-1 was stored at $-20^{\circ}C$ until use, and CM-2 was prepared just before use as a culture medium. CM-3 was cocultured with embryos and retrieved just before use. CM-4 and CM-5 were derives from the microfilteration of CM-2 and CM-3, respectively, using Microcon-10 (10 kDa molecular weight cut-off). The percentage of the embryos developed to hatched blastocyst stage and the level of superoxide anion in supernatant from medium alone culture (control), coculture, and contactless coculture were measured. Results: The rates of embryo development to the hatched blastocyst stage were significantly higher in coculture (43%) than in control (0%) (p<0.05). The CM-1 group had no embryo development since 2-cell embryonic stage, whereas the CM-2, CM-3, CM-4 and CM-5 groups had the improved development to 4 or 8 cell embryo stage, but the similar rate of development to hatched blastocyst compared to control. The effect of coculture on embryo development was disappeared in the contactless coculture group. The level of superoxide anion was significantly reduced in coculture group compared to control. Conclusion: It is concluded that the present coculture system overcomes the 2-cell block in vitro and improves the embryo development. This beneficial effect may be due to the direct cell-cell contact between embryo and helper cells or the removal of deleterious components from medium rather than the embryotrophic factors.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.43-52
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• 1998

The embryogenesis stimulating activity(ESA) had been shown in co-culture of embryos with bovine oviduct epithelial cell(BOEC) and culture in BOEG-conditioned medium. The present study was undertaken to purify and quantify the embryotropic proteins and to determine the optimum concentration of the embryotropic protein for the proper development of embryos. In BOEC-conditioned medium, five major bands of proteins were detected(66, 53, 40, 32 and 24 kDa) by SDS-PAGE. From these proteins, 288pg of protein that had a 32kDa molecular weight was purified by gel filtration column and perfusion chromatography ion-exchange column. When purified protein was supplemented to the in vitro culture media at various concentrations in protein-free media, 2.5$\mu$g /ml supplement group showed significantly higher rates of embryo development into morula /blastocyst stages than other groups(p<0.05). In conclusion, we purified 32kDa protein from BOEC-conditioned medium and this protein showed optimum embryogenesis stimulating effect at 2.5$\mu$g /ml.

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.211-219
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• 2009

In the process of oyster mushroom production, loading work of culture medium needs the most intensive labor power and cost. Therefore, the development of culture medium loading machine causes to reduce the manpower and cost. The main objectives of this study are identify cultivating environment, physical properties of culture medium and to make an element design of culture medium loading machine. The results are summarized as follows: 1. The moisture content and density of popularly used culture medium were 70%(w.b), $26\;kg/m^3$, respectively. 2. Pressure of the blower increased as the impeller speed increased, and the opening ratio of pressure controller decreased. 3. Recommendable c1earance(${\delta}$) between an impeller plate and a blower case was 25 mm at an impeller speed of 3183 rpm 4. Discharge device of type B with a hopper and suit was better than type A with a hopper.

• Journal of Korea Planning Association
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• v.54 no.3
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• pp.63-74
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• 2019

Korean government has implemented policies to strengthen the competitiveness of small and medium sized cities. However, since it is often difficult to enhance the competitiveness through individual projects, many local governments in metropolitan areas are working together to pursue local growth. On the other hand, small and medium sized cities that are not included in metropolitan areas due to their spatial limitations have difficulties in implementing effective growth policies. Given this background, the purpose of this study is to identify the functional correlation based on urban interactions and develop functional econometric model for the economic growth of small and medium sized cities. This study uses spatial econometrics models and functional weight matrix to identify the effects of functional networks on small and medium sized cities. The results show the effect of functional networks on the growth of small and medium sized cities and provide policy implications for regional spatial planning that addresses effective management of small and medium sized cities.

• Korean Journal of Animal Reproduction
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• v.19 no.1
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• pp.9-14
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• 1995

This study was conducted to investigate the effect of energy source on development of in vitro development of in vitro matured and fertilized porcine 2-cell embryos. The relative preferences of glucose, lactate and pyruvate for in vitro development of porcine 2-cell embryos were determined. The results obtained are as follows. 1. 33.3, 20.8 and 29.2% of porcine embryos reached morula stage in addition to lactate, glucose, and both glucose and lactate in the culture medium as energy source, respectively. 2. 38.5, 15.4 and 26.9% of porcine embryos reached morula stage in addition to pyruvate, glucose, and both glucose and pyruvate in culture medium as energy source, respectively. 3. 42.9, 21.4 and 28.6% of porcine embryos reached morula stage in addition to pyruvate and lactate, glucse alone, and glucose, lactate and pyruvate in culture medium as energy source, respectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.95-106
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• 1995

This study is aimed at development a plan to strengthen the competitiveness in technology of small and medium manufacturing enterprises, which can be assumed mainly by small and medium manufacturing companies, to improve the competitiveness of domestic industry. To remove these obstacles and strengthen the technological competitiveness, internally it is required to change the attitude of management about the development and innovation of technology first. Promotion of favorable atmosphere for the technological development and organized activity to acquire technological information are additional requirements. In conclusion, to survive the competition and to secure national industrial competitiveness, each individual company needs to endeavor for technological innovation and improvement in product quality and productivity.