• Journal of Embryo Transfer
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• v.11 no.3
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• pp.301-307
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• 1996

This study was carried out to produce twin calves by embryo transfer in Hanwoo and investigate the pregnancy and twin rate by recipient's conditions. All recipients were bred at estrus by artificial insemination with Hanwoo semen and then transfered an additional embryo produced in vivo or in vitro to tbe uterine horn contralateral to the corpus luteum on Day 7. The results obtained were as follows ; 1. The pregnancy rate was higher in young recipients of 3 years (68.8%) than in old ones of 10 years and greater(36.4%). And for CL size pregnancy rate was 57.9, 45.4 and 60.1% in large, medium and small size of CL of recipients, respectively. 2. 447recipients were transferred an additional embryos at 7th day after Al and average pregnancy rate was 57.5% and twin production rate was 22.2%. 3. Average pregnancy and twin production rate by direct transfer methods of frozenthawed IVF embryos was 56.0 and 16.7%. 4. The ratio of male to female twin in a total of 55 twin pairs was 54.6%, and average gestation lengths of male to female and female to female twin were 280.6$\pm$5.4 and 279.715.4 days, respectively. Average birth weight of twins was beavior in male and male twin(23.2i5.8kg) than in male and female twin(20.5$\pm$2.6kg).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.305-307
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• 2021

In this paper, we propose a study related to the development of a Digital-Twin platform using a smart factory based CPPS (Cyber Pysical Production System) using ICT (Information Communication Technology) technology. The platform developed through this study performs a 3D model simulation function in conjunction with P3R (Product, Process, Plant, Resource) including BOP (Bill of Process) management function from the preceding manufacturing process planning stage. In addition, we propose a digital twin platform that can predict production processes, equipment, layout, and production. The platform proposed through this paper proposes a feature that can manage the entire smart factory manufacturing process from the initial planning design stage to the manufacturing, production, operation, and maintenance stages.

• Journal of Embryo Transfer
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• v.14 no.3
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• pp.171-176
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• 1999

This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system (modified TALP ; mTALP) on the conception of embryos transferred, and pregnancy and twin birth rates after transfer of fresh or frozen-thawed bovine blastocysts produced in vitro were also evaluated. Oocytes from the slaughterhouse ovaries were matured and fertilized using general protocol. The results obtained were as the following. The pregnancy rate after transfer was higher in co-culture group than in mTALP group, but was not signficantly different, and there is no difference between fresh embryo group and frozen-thawed embryo group in conception rate. The conception rate was not different whether 3∼4 blastocysts or 2 blatocysts transferred into a recipient, but the production rate of twin calves was significantly higher (p<0.05) when 3∼4 embryos transferred. The average birth weight of twin calves(24.38kg) was numerically, but not significantly lighter than that of single calves(26.68kg).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.204-206
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• 2022

Digital twin, which is evaluated as the core of smart factory advancement, is a technology that implements a digital replica in the virtual world with the same properties and functions of assets in the real world. Since the smart factory to which digital twin is applied can support services such as real-time production process monitoring, production process simulation, and predictive maintenance of facilities, it is expected to contribute to reducing production costs and improving productivity. AAS (Asset Administration Shell) is an essential technology for implementing digital twin and supports a method to digitally represent physical assets in real world. In this paper, we design AAS for manufacturing data gathering to be used in real-time CNC (Computer Numerical Control) monitoring system in operation by considering manufacturing facility in smart factory as assets.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.91-102
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• 1997

This study was carried out to enhance the efficiency of Korean Native cattle embryos and establish the techniques for producing the twin calves. Bisected embryos without zona pellucida which were divided by simple method not using holding pipette or whole two embryos were transferred to recipients.The pedigrees of monozygotic twin calves produced by transfer of bisected pair embryos were identified. The results obtained were as follows ; The average successful bisection rate was 89.16%. The embryos of blastocyst stage (91.66%) were bisected successfully at significantly (P<0.05) higher rate, compared with the morula stage embryos (86.66%). The average survival rate of bisected embryos following 24 hours culture was 59.02%. The survival rate of morula stage embryos (62.50%) was significantly (P<0.05) higher than that of blastocyst stage embryos (55.5%). For the production of monozygotic twin calves, ten pairs of flesh or frozen demi-em- lymphocytes antigen, the twin calves produced by transfer of bisected pair embryos of Korean Native cattle were identified in pedigrees and confirmed as monozygotes.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1735-1740
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• 2005

Forty-two single-bearing and 42 twin-bearing mature Angus${\times}$Hereford cows were allocated, seven per cell to 3 replications of 2 stocking rates (3.2 cows/ha; medium stocking rate [MSR], and 3.8 cows/ha; high stocking rate [HSR]) to graze summer-active and winter-active pastures from late pregnancy to the weaning of their calves. Cow liveweights and growth of calves were recorded as well as estimates of pasture quantity and forage intake. Pasture quantity did not differ in the paddocks grazed by single- and twin-bearing cows during pregnancy, nor effectively did forage intake. Subsequently, intake was higher during mid-lactation especially with twin-rearing cows (25% higher than single-rearing cows at the MSR; 9% at the HSR). However, quantity of pasture decreased for twin-rearing cows and was less than that available to single-rearing cows as lactation progressed. Liveweights of twinrearing cows decreased by 16% from late pregnancy to weaning at the MSR, and by 14% at the HSR, compared to decreases of 1% for single-rearing cows. Twin calves were lighter at birth, had slower growth rates, and were lighter at weaning than single calves. In spite of weaning smaller calves twinning increased the output (kg of calf weaned) per cow and per ha, and increased the efficiency (kg calf weaned per unit of forage eaten by the cow) over single calf production by 46% at the MSR and by 58% at the HSR. Twinning also increased the marginal returns from investment in high input pastures required by the enterprise.

• Journal of Practical Engineering Education
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• v.13 no.3
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• pp.483-490
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• 2021

In this paper, we proposed the development of a smart factory intergrated technology education platform using smart factory based CPPS (Cyber Physical Production System) and VR (Vitrual Reality) technology and educational methods using the platform. A platform has been developed to learn how to integrate 3D digital twin and BOP (Bill of Process)-based manufacturing processes. In addition, Digital Twin established a smart factory-based integrated education platform by linking mechanical systems, digital twins, and virtual reality through the OPC-UA server. Based on this platform, the smart factory integration platform is proposed to have individual elements of the smart factory integration platform through BOP-based digital twin simulation, OPC-UA integration, MES system, SCADA system, and VR interworking.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.47-56
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• 2000

This study was carried out to improve a technique of embryo transfer for twin calves production in Hanwoo cattle. Blastocysts for the donor of embryo transfer were classified into three criteria by accessment of morphology; early blastocyst, blastocyst and expanded blastocyst. Tow embryos were introduced transcervically into utrerine horn either of Hanwoo or Holstein by ipsilaterally or contralaterally to the corpus luteum. Thiry-six out of 57 recipients cows were inseminated by artificially on the next day of estrus, and followed by transfer of embryos into contralaterally. The pregnance rates of recipients following transfer of bovine embryos of day 7, 8 and 9 was 43.5, 18.2 and 8.3%, respectively. These results appeared that these was a significant (P<0.05) difference between on day-7 embryos and day-9 embryos, but not between on day-8 and day-9 embryos. Although there was not significant(P<0.05) difference in the pregnancy rates between the blastocysts(11/25, 44%) and expanded blastocysts(2/19, 10.5%) and between the blastocysts and early blastocysts(2/13, 15.4%), the embryos at blastocyst stage are more suitable than others for obtaining higher rate of pregnancy. There was no significant difference on pregnancy of the embryos transferred prior to presence(6/21, 29%) or absence (9/36, 25%) of artificial insemination. On pregnancy of Holstein, 2(15.4%) out of 13 recipients were pregnant in heifer. Similar Pregnancy rates were obtained between 1∼2 parities and 3∼4 parities by 30% (6/20) and 27.3%(3/11), respectively. Taken together, there was not significant difference in pregnancy rate due to small number of recipients used for this experiment. Both of Hanwoo and Holstein introduced the embryos by contralsterally to the corpus luteum were slightly higher pregnancy rate compare to by ipsilaterally (12/41, 29.3% vs, 3/16, 18.8%). The ratio of production of twin and single calves in Holstein was 20% (9/45) and 2.2% (1/45), respectively. However, in Hanwoo cows both of production of twin and single were similar as 8%. This result suggests that Holstein as recipients was superior to Hanwoo cows for production of twin calves. Out of all 15 pregnant, 12(80%) were produced a total of 22 normal calves in which the others composed of abnormal, as judging as 2(13.3%) for abortion and 1(6.6%) for stillbirth during the pregnant period.

• Journal of Welding and Joining
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• v.26 no.4
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• pp.44-49
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• 2008

Generally, wear plate is steel plate having improved surface contact strength and impact strength by surface hardening which is welded using materials with good corrosion resistance, wear resistance and thermal resistance property. CFP GMAW(Compound Filler Plate Gas Metal Arc Welding) is the cladding method using GMAW with the CFP, which is bound with waterglass, on the substrate. It has advantages of reducing compound powder loss, uniform penetration, and preventing hardness decrease. To develope mass production technique of CFP GMAW process for production of high quality wear plate, the method for controling shallow penetration and increasing productivity is required. In this study, twin torch method applied to CFP GMAW process for increasing productivity. And the method was developed by controling penetration control, CFP dry time, gas formation flux and water glass concentration. As a result, applying twin torch method to CFP GMAW process was possible and high quality wide bead could be made without overlap joint.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2399-2416
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• 2024

The current automotive industry is transitioning from Internal Combustion Engine (ICE) vehicles to Electric Vehicles (EVs), adopting a mixed assembly production approach to respond to fluctuating demand. While mixed assembly production offers the advantages of lower investment costs and flexibility in responding to changing demands, the supply of EV components requires more extensive provisioning compared to ICE vehicle components, potentially leading to unexpected issues such as congestion of transport vehicles. This study proposes a digital twin system architecture that uses Discrete Event Simulation (DES) and Business Intelligence (BI) tools to specifically address logistics challenges. The proposed architecture facilitates real-time, data-driven decision making across three layers; Data source, Simulation, and BI. It was implemented in factories engaged in the mixed assembly production of ICE and EV vehicles. The simulation challenges involve a tier 1 vendor supplying parts to Korean automobile manufacturers that produce both ICE and EV parts. A total of 240 scenarios were created to run the simulations. The deployment of the proposed architecture demonstrates its capability to quickly respond to diverse experimental situations and promptly identify potential issues.