• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.4
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• pp.1216-1231
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• 2021

With the increase in the population of our cities and the rapid increase in the number of private cars, urban traffic has become more and more congested. At this stage, urban public transportation has become one of the main ways to improve urban traffic congestion. Aiming at the problem of how to improve the basic capacity of buses in multi-line transfer stations, this paper conducts simulation research based on anylogic software. Through micro-simulation analysis of vehicles entering, stopping, and exiting the station, combined with the delay model theory, the vehicle is given Stop organization optimization and station layout improvement methods, so that vehicles can run in the station more stably, smoothly and safely. Case analysis shows that applying this method to the roadside parking problem, the main and auxiliary bus stations have a significant improvement in operating capacity compared with the conventional tandem double bus stations, and the service level of the main and auxiliary bus stations has been significantly improved.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2007.10a
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• pp.609-609
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• 2007

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.91-99
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• 2014

Oxygen consumption is a useful parameter for evaluating mammalian embryo quality, since individual bovine embryos was noninvasively quantified by scanning electrochemical microscopy (SECM). Recently, several approaches have been used to measure the oxygen consumption rates of individual embryos, but relationship between oxygen consumption and pregnancy rates of Hanwoo following embryo transfer has not yet been reported. In this study, we measured to investigate the correlation between oxygen consumption rate and pregnancy rates of Hanwoo embryo using a SECM. In addition to, the expression of pluripotent gene and anti-oxidant enzyme was determined using real-time PCR by extracting RNA according to the oxygen consumption of in vivo embryo. First, we found that the oxygen consumption significantly increased in blastocyst-stage embryos (blastocyst) compared to early blastocyst stage embryos, indicating that oxygen consumption reflects the embryo quality (Grade I). Oxygen consumption of blastocyst was measured using a SECM and total cell number of in vitro blastocyst was enumerated by counting cells stained by propidium iodide. The oxygen consumption or GI blastocysts were significantly higher than those of GII blastocysts ($10.2{\times}10^{15}/mols^{-1}$ versus $6.4{\times}10^{15}/mols^{-1}$, p<0.05). Total cell numbers of in vitro blastocysts were 74.8, 90.7 and 110.2 in the oxygen consumption of below 10.0, 10.0~12.0 and over $12.0{\sim}10^{15}/mols^{-1}$, respectively. Pregnant rate in recipient cow was 0, 60 and 80% in the transplantation of embryo with the oxygen consumption of below 10.0, 10.0~12.0 and over $12.0{\times}10^{15}/mols^{-1}$, respectively. GPX1 and SOD1 were significantly increased in over -10.0 group than below 10.0 groups but in catalase gene, there was no significant difference. On the other hand, In OCT-4 and Sox2, pluripotent gene, there was a significant difference (p<0.05) between the below-10.0 ($0.98{\pm}0.1$) and over 10.0 ($1.79{\pm}0.2$). In conclusion, these results suggest that measurement of oxygen consumption maybe help increase the pregnant rate of Hanwoo embryos.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.311-315
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• 2005

This study was conducted to investigate the effects of disregarding of heat detection on embryo production in superovulation of Hanwoo cows. Donors which showed 1 or 2 times of normal heat and had no abnormality of reproductive tract were selected The superovulation was performed injection of 2.5 mL FSH (Antorin R-10, Japan) 2 times on 5 days before next heat and continuously with the reduction of dose to 0.5 mL of first injection 2 times in a day for next 3 days. Otherwise, the donors of CIDR group were inserted CIDR plus (with the capsule of estradiol benzoate 10 mg) on Day 10 from standing heat for 9 days. On 6 days from insertion of CIDR, FSH was injected above same manners. The response according to the natural heat and CIDR were $82.2\%,\;89.7\%$, respectively. There were no difference between both treatments. The recovery rates of embryos were 7.7, 10.5, respectively and transferable embryos were 3.4, 3.8. There showed significant difference between both treatments (p<0.05). These results suggested that disregarding of heat detection in superovulation could be produced transferable embryos for embryo transfer and preserve the donors from the excess hormonal administration and maintain the economical lift span of genetically available Hanwoo donors.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2001.10a
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• pp.15-15
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• 2001

• Progress in Superconductivity and Cryogenics
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• v.24 no.3
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• pp.62-67
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• 2022

Liquid hydrogen (LH₂) has a higher density than gaseous hydrogen, so it has high transport efficiency and can be stored at relatively low pressure. In order to use efficient bulk hydrogen in the industry, research for the LH₂ supply system is needed. In the high-pressure hydrogen station based on LH₂ currently being developed in Korea, a heat exchanger is used to heat up supercritical hydrogen at 700 bar and 60 K, which is pressurized by a cryogenic high-pressure pump, to gas hydrogen at 700 bar and 300 K. Accordingly, the heat exchanger used in the hydrogen station should consider the design of high-pressure tubes, miniaturization, and freezing prevention. A helical heat exchanger generates secondary flow due to the curvature characteristics of a curved tube and can be miniaturized compared to a straight one on the same heat transfer length. This paper evaluates the heat transfer performance through parametric study on the distance between coils, guide effect, and anti-icing design of helical heat exchanger. The helical heat exchanger has better heat transfer performance than the straight tube exchanger due to the influence of the secondary flow. When the distance between the coils is uniform, the heat transfer is enhanced. The guide between coils increases the heat transfer performance by increasing the heat transfer length of the shell side fluid. The freezing is observed around the inlet of distribution tube wall, and to solve this problem, an anti-icing structure and a modified operating condition are suggested.

• Journal of Embryo Transfer
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• v.26 no.3
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• pp.187-193
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• 2011

This study was carried out to establish most suitable freezing condition, to evaluate the different glycerol concentration of freezing and thawing rates on motility, viability, membrane integrity and acrosome intecrity of frozen Korean Jeju Black Bull spermatozoa, Semen was collected from a Korean Jeju Black Bull using an artificial vagina and transported to the laboratory. The semen was extended gradually 1:5 then cooled slowly for 2 hrs to 4$^{\circ}C$. The semen was diluted 1:1 with cryoprotectant extenders (3%, 5% and 7% glycerol) and equilibrated for 2 hrs at cold chamber and packed to 0.5 ml straws. The semen straws were located above 3 cm of liquid nitrogen for 5 minutes, above 5 cm for 10 min and above 8 cm for 10 min. And then the frozen straw was plunged into LN$_2$. The presented straws were examined the viability and motility after thawed at 37$^{\circ}C$ water bath. The viability and membrane integrity immediately post-thawing were significantly higher in samples frozen in 7% glycerol than 3% and 5% glycerol (p<0.05). After CTC staining to assess acrosome integrity, F pattern was significantly increased, but B pattern was significantly decreased in 7% glycerol (p<0.05). Freezing distance of 5 cm from liquid nitrogen and pre-cooling for 10 min yield better survival and membrane integrity, but not significant difference. However, AR pattern according to CTC staining was significantly decreased in 3 cm for 5 min.

• Proceedings of the KOR-KST Conference
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• 1995.05b
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• pp.15-50
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• 1995

• Journal of the Korean association of regional geographers
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• v.15 no.6
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• pp.789-802
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• 2009

The purpose of this study is to reveal general features and toponymical characteristics of station names of Seoul metropolitan railway system. Principal results of this study are as follows. At the present time of December, 2009, the number of station which is run is 508, the number of transfer station is 61 and the number of station which has another name is 89. Two-letter station names are 61.99%, and three-letter station names are 20.59%. Geographical names used as station name are classified into three types : administrative, physical, and human placename. In the three types, administrative placename is the most and physical placename is the least. In the administrative placename, the name of 'Dong' is the most. In the physical placename, the name of mountain is the most. In the human placename, the name of facilities is the most.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.383-389
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• 2011

Until now, in planning and constructing KTX and the Express Way, the connectivity and transfer between these facilities have not been considered. In this study the effect of mode choice behavior by connecting KTX and the Express Way is analyzed through estimating Multinomial Logit Model and Binary Logit Model. The SP and RP surveys to develop these models were carried out and the data were selected from the passengers using the KTX station, Express Bus Terminals and Rest Areas in the Express Way. To test the effect of connectivity and transfer in the field, the case study for Dongtan KTX station was carried out. According to the results, connecting the KTX station and the Express Way has the effect of increasing the demand by 30%. And this is caused by saving about 120 minutes of traveling time from Seoul to Pusan. This study shows that the connectivity and transfer can increase the efficiency of transportation system and the improvement in the mobility and accessibility will maximize the usages of these two facilities.