• Title/Summary/Keyword: Early Design Stage

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Effect of Monosodium Glutamate on In Vitro Oocyte Maturation and Embryonic Development after Parthenogenesis in Pigs

  • Kim, Minji;Shin, Hyeji;Lee, Joohyeong;Lee, Seung Tae;Lee, Eunsong
    • Journal of Embryo Transfer
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    • v.32 no.4
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    • pp.297-304
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    • 2017
  • This study was designed to determine the effect of monosodium glutamate (MSG) on in vitro maturation (IVM) of oocytes and early development of parthenogenesis (PA) embryos in pigs. Each IVM and IVC medium was supplemented with various concentrations (0, 0.1, 0.5 and 5 mM) of MSG and non-essential amino acids (NEAA) depending on the experimental design. Immature pig oocytes were matured for 44 h and then oocytes reached metaphase II (MII) stage were electrically activated to induce parthenogenesis (PA). When immature oocytes were treated with MSG in the absence of NEAA during IVM, nuclear maturation (83.1-87.1%), intra-oocyte glutathione content, cumulus expansion, and cleavage (91.4-93.4%) of PA embryos were not influenced by MSG treatment at all concentrations. However, blastocyst formation of PA embryos was significantly increased by 5.0 mM MSG ($45.3{\pm}6.2%$) compared to control ($25.6{\pm}3.4%$). MSG treatment during IVM in the presence of NEAA did not show significant effect on nuclear maturation of oocytes and blastocyst formation after PA while 0.5 mM MSG ($89.3{\pm}1.9%$) decreased (P < 0.05) cleavage of PA embryos compared to 0.1 mM MSG ($94.6{\pm}1.1%$). When PA embryos were treated for 7 days with MSG during IVC, 5.0 mM MSG significantly decreased blastocyst formation ($27.8{\pm}4.9%$) compared to no treatment ($41.4{\pm}1.9%$) while no decrease in blastocyst formation was observed in 0.1 and 0.5 mM ($37.4{\pm}3.4%$ and $34.4{\pm}2.6%$, respectively). Our results demonstrated that 5 mM MSG in a NEAA-free chemically defined maturation medium showed positive effect on PA embryonic development while 5 mM MSG treatment during IVC was deleterious to PA embryonic development in pigs.

The Analysis of Elasto-Plastic Thermal Stresses for Welding Part in Double Capstan Drum (더블 캡스턴 드럼의 용접부에 대한 탄소성 열응력해석)

  • 김옥삼
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.4
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    • pp.329-336
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    • 2000
  • Welding is a important technological method in mechanical engineering. $CO_2$MAG(metal active gas) welding means that metal part in double capstan drum for the inshore and costal vessels are joined by melting(with or without a filler material) or that new material is added to a metal part by melting. The thermal stresses appear due to a non-uniform temperature field, inhomogeneous material properties, external restraint and volume changes during phase transformations. In this study analysis the elasto-plastic thermal stresses distribution of welding part in double capstan drum for the inshore and costal vessels using finite element method (FBM). Therefore it calculates the numerical value that can be applied to the optimum design of welding parts and the shapes. The significant results obtained in this study are summarized as fellows. At early stage of the cooling after welding process, the abrupt thermal stresses gradient has been shown in the vicinity of welding part. In the thermal stresses analysis due to temperature gradient and heat shocking maximum stress was occurred of welding part and stresses were distributed from 54MPa~48MPa.

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Cable-free Seismic Acquisition System (무선 탄성파 탐사 시스템)

  • Lee, Donghoon;Kim, Byung-Yeop;Jang, Seonghyung
    • Geophysics and Geophysical Exploration
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    • v.19 no.3
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    • pp.164-173
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    • 2016
  • Cable-free seismic technology is to acquire seismic data with independent receivers which are not connected by cables. This is an effective method for survey designs with less topographical conditions. With technology advancement for cable-free receivers, reliable data quality, easy deployment, and picking up the receivers, the cable-free technology has begun to apply to land seismic acquisition. In this study we introduced a cable-free seismic system and its equipment. We tried to build up the cable-free seismic technology through the field application. In the seismic tomography field applications, the seismic signals of the cable-free receiver and cabled receiver with the same distance from the source show the same phase in early stage. The difference of the first arrival times between two signals is less than 0.4 ms, which could be accepted. In the field application for seismic reflection exploration, we acquired shot gathers with different source depth and dynamite charge. The shot gathers from cable-free and cabled system are similar to each other. With an efficient method for receiver deployment and survey design, the application of the cable-free technology will increase.

The LVC Linkage for the Interoperability of the Battle Lab (Battle Lab에서의 상호운용성을 위한 LVC 연동방안)

  • Yun, Keun-Ho;Shim, Shin-Woo;Lee, Dong-Joon
    • Journal of the Korea Society for Simulation
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    • v.21 no.1
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    • pp.81-88
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    • 2012
  • In the M&S filed, The Battle Lab is available for acquisition, design, development tool, validation test, and training in the weapon system of development process. Recently, the Battle Lab in the military of Korea is still in an early stage, in spite of importance of battle lab construction. In the environment of network centric warfare, a practical use of the M&S which is connecting live, virtual and constructive model can be applied to all field of System Engineering process. It is necessary thar the Battle Lab is not restricted by time and space, and is possible for the technical implementation. In this paper, to guarantee the interoperability of live and virtual simulation, virtual simulators connect live simulators by using the tactical data link. To guarantee the interoperability of virtual and constructive simulation, both virtual simulators and constructive simulators use the RTI which is the standard tool of M&S. We propose the System that constructed the Air Defence Battle Lab. In case of the approach of target tracks, The Air Defence Battle Lab is the system for the engagement based on a command of an upper system in the engagement weapon system. Constructive simulators which are target track, missile, radar, and launcher simulator connect virtual simulators which are MCRC, battalion, and fire control center simulators using the RPR-FOM 1.0 that is a kind of RTI FOM. The interoperability of virtual simulators and live simulators can be guaranteed by the connection of the tactical data links which are Link-11B and ATDL-1.

Numerical Simulation of Full-Scale Crash Impact Test for Fuel Cell of Rotorcraft (회전익항공기 연료셀 충돌충격시험 Full-Scale 수치모사)

  • Kim, Hyun-Gi;Kim, Sung Chan;Kim, Sung Jun;Kim, Soo Yeon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.5
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    • pp.343-349
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    • 2013
  • Crashworthy fuel cells have a great influence on improving the survivability of crews. Since 1960's, the US army has developed a detailed military specification, MIL-DTL-27422, defining the performance requirements for rotorcraft fuel cells. In the qualification tests required by MIL-DTL-27422, the crash impact test should be conducted to verify the crashworthiness of fuel cell. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. Because the crash impact test itself takes a long-term preparation efforts together with costly fuel cell specimens, the failure of crash impact test can result in serious delay of a entire rotorcraft development. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error with full-scale fuel cells. Present study performs the numerical simulation using SPH(smoothed particle hydro-dynamic) method supported by a crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the resulting equivalent stresses of fuel cell itself are calculated and vulnerable areas are also evaluated.

Water Supply Alternatives for Drought by Weather Scenarios Considering Resilience: Focusing on Naju Reservoir (회복탄력성을 고려한 기상 시나리오별 가뭄 용수 공급방안: 나주호를 중심으로)

  • Park, JinHyun;Go, JeaHan;Jo, YoungJun;Jung, KyungHun;Sung, MuHong;Jung, HyoungMo;Park, HyunKyu;Yoo, SeungHwan;Yoon, KwangSik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.5
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    • pp.115-124
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    • 2018
  • Resilience has been widely used in various fields including design and operation of infrastructures. The resilient infrastructures not only reduce the damage scale of various disasters but also reduce the time and cost required for restoration. However, resilience rarely applied to promote efficient management of agricultural infrastructures. Recently, drought is an aggravating disaster by climate change and need countermeasures. Therefore, we tried to demonstrate evaluating measures in case of drought under consideration of resilience. This study applied the robustness-cost index (RCI) to evaluate alternative solution of the supply problem of a large agricultural reservoir under drought conditions. Four structural alternatives were selected to estimate the robustness index (RI) and the cost index (CI) to obtain the RCI values. Structural alternatives are classified into temporary measures and permanent measures. Temporary measures include the development of a tube wells and the installation of the portable pump, while the permanent measures include the installation of a pumping stations and the pumping water to the reservoir (Yeongsan River-Naju reservoir). RCI values were higher in permanent measures than those of temporary measures. Initial storage of the reservoir also affected RCI values of the drought measures. Permanent measures installation and management of early stage of the reservoir storage shortage was identified as the most resilient system.

Current Limiting and Recovery Characteristics of Two Magnetically Coupled Type SFCL with Two Coils Connected in Parallel Using Dual Iron Cores (이중철심을 이용한 병렬연결된 자기결합형 초전도한류기의 전류제한 및 회복특성)

  • Ko, Seok-Cheol;Lim, Sung-Hun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.717-722
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    • 2016
  • In this paper, in order to support the peak current limiting function depending on the intensity of the fault current at the early stage of failure, a two magnetically coupled type superconducting fault current limiter (SFCL) is proposed, which includes high-Tc superconducting (HTSC) element 1, where the existing primary and secondary coils are connected to one iron core in parallel, and HTSC element 2, which is connected to the tertiary winding using an additional iron core. The results of the experiments in this study confirmed that the two magnetic coupling type SFCL having coil 1 and coil 2 connected in parallel using dual iron cores is capable of having only HTSC element 1 support the burden of the peak current when a failure occurs. The reason for this is that although HTSC element 1 was quenched and malfunctioned because the instantaneous factor of the initial fault current was large, the current flowing to coil 3 did not exceed the critical current, which would otherwise cause HTSC element 2 to be quenched and not function. In order to limit the peak current upon fault through the sequential HTSC elements, the design should allow it to have the same value as the low value of coil 1 while having coil 3 possess a higher self-inductance value than coil 2. In addition, a short-circuit simulation experiment was conducted to examine and validate the current limiting and recovery characteristics of the SFCL when the winding ratio between coil 1 and coil 2 was 0.25. Through the analysis of the short-circuit tests, the current limiting and recovery characteristics in the case of the additive polarity winding was confirmed to be superior to that of the subtractive polarity winding.

Lessons from Haitai Distribution Inc's experience in Korea

  • Cho, Young-Sang
    • Journal of Distribution Science
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    • v.9 no.3
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    • pp.25-36
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    • 2011
  • Owing to the rapid growth of hypermarket/discount store formats since 1996, Korean retailing has suddenly attracted the significant attention from researchers. Before the emergence of large scale retailers such as E-Mart, Lotte Mart and Tesco Korea, there were the two retail formats who led the Korean retailing in the modern retailing history: department store and supermarket formats. Nevertheless, there has been little literature concerned about the two retail formats as a case study, while some authors have paid their attention to hypermarket/discount store formats. In addition, when mentioning the development process of retailing history, it is less likely that authors have made an effort to illustrate supermarket retailing history. In order to regard supermarket retailing as part of the Korean retailing, it is interesting to look at a representative supermarket retailer, Haitai, who was one of the subsidiaries of Haitai chaebol. Based on supermarket retailing, the company which was established as a joint venture in 1974 led a supermarket retailing in the Korean modernised retailing history. Before analysing whether Haitai failed or not, the definition of failure should be illustrated. With regard to the term, failure, in the academic world, authors have interchangeably used the following terms: failure, divestment, closure, organisational restructuring, and exit. To collect research data as a case study, the author adopted an in-depth interview method. The research is based on research interviews with 13 ex-staff who left after Haitai went bankruptcy, from store management department to merchandise department. By investigating Haitai's experiences through field interviews, the research found that Haitai restructured organisational decision-making process at the early stage when companies started to modernise organisational charts, benchmarking sophisticated retailing knowledge through the strategic alliance with a Japanese retailer. In respect of buying system, the company established firmly buying functions by adopting central buying system, and further, outstandingly allocated considerable marketing resources to the development of retailer brands with the dedicated team of retailer brand development. In the grocery retailing, abandoning a 'no-frill' packaging concept, the introduction of retailer brand packaging equal to, or better than national brand packaging design, encouraged other retailers to change their retailer brand development strategies. In product sourcing ways, Haitai organised for the first time the overseas sourcing team with the aim of improving the profit margins of foreign products and providing exotic products for customers, followed by other retailers. Regarding distribution system, the company introduced the innovative idea which delivered products ordered by stores directly to each store withboth its own vehicles and its own warehouse in which could deal with dry foods, chilly foods, frozen food, and non-foods, and even, process produce. In addition, Haitai developed many promotional methods to attract more customers like 'the guarantee of the lowest price', and expanded its own business to US in 1996, although withdrew, because of bankruptcy in 1997. Together with POS introduction in 1994, Haitai made a significant contribution to the development of the Korean retailing, influencing other retailers in many aspects. As a case study, the study has provided a number of lessons from Haitai's experiences for academicians and practitioners, suggesting that its history should be involved in the Korean modernised retailing.

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Numerical Analysis of Phase Behavior and Flow Properties in an Injection Tubing during Gas Phase CO2 Injection : Application of Demonstration-scale Offshore CO2 Storage Project in the Pohang Basin, Korea (기체상태의 CO2 주입시 주입관내 상변화 및 유동 특성의 수치해석적 연구 : 포항분지 해상 중소규모 CO2 지중저장 사업에 적용)

  • Jung, Woodong;Sung, Wonmo;Han, Jeong-Min;Song, Youngsoo;Wang, Jihoon
    • Journal of the Korean Institute of Gas
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    • v.25 no.4
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    • pp.10-18
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    • 2021
  • CO2 storage technology in an aquifer is one of the most effective way to decrease global warming due to a high storage capacity and economics. A demonstration-scale offshore CO2 storage project was performed in a geological deep aquifer in the Pohang Basin, Korea for a technological development of large-scale CO2 storage. A challenging issue in the early design stage of the project was to establish the proper injectivity during CO2 injection. To solve this issue, injection conditions were calculated by calculating injection rate, pressure, temperature, CO2 phase change, and thermodynamic properties. For this study, we simulated and numerically analyzed CO2 phase change from gas to supercritical phase and flow behavior in transport piping and injection tubing using OLGA program. Our results provide the injectivity conditions of CO2 injection system combined with a bottomhole pressure of an aquifer.

Effect of Seeding Density and Seeding Methods on the Dry Matter Yield of Barnyard Millet

  • Lee, Bae Hun;Yang, Seung Hak;Oh, Mirae;Choi, Ki Choon;Park, Hyung Soo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.3
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    • pp.205-209
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    • 2021
  • Barnyard millet (Echinochloa esculenta) can be processed through soiling, hay, and silage, depending on the weather conditions during harvesting. However, research on barnyard millet is insufficient, and standards for cultivar, seeding density, and fertilizers have not been established. This study was conducted to examine the effects of seeding density and seeding methods on dry matter yields. For this, we used the early-maturing (Shirohie millet) variety of the barnyard millet. The experimental design included different seeding density (10 kg/ha, 15 kg/ha, 20 kg/ha (standard seeding density), 25 kg/ha and 30 kg/ha), and different methods of seeding (drill seeding and broadcast seeding). The seeding date was May 13, 2021, and the harvest date was July 13, 2021. Harvesting was carried out when the heading reached 40 %. Lodging occurred at 5, 9 and 7 at 20, 25 and 30 kg/ha densities in the broadcast seeding, but not in the drill seeding. With decreasing density of seeding, tillage number showed an increasing trend in both drill seeding and broadcast seeding (p>0.05). The plant heights were comparable in both drill seeding and broadcast seeding (p>0.05). The heading stage of barnyard millet was checked July 7 for drill seeding, and, on July 8 for broadcast seeding. It took 62 days, i.e., till July 13 for the heading to reach 40 % of the output. The dry matter yield of barnyard millet was significantly higher at the seeding density of 30 kg/ha, for both the methods of seeding (p<0.05). There was no difference in the chemical composition of grain, based on the seeding method and seeding density. However, as the seeding density increased, the CP, NDF, ADF, and TDN contents increased in both drill seeding and broadcast seeding. We found that, the dry matter content was the highest at the seeding density of 30 kg/ha for both the methods of seeding, but this was only 1.3 times higher than that of 10 kg/ha. Considering the seed price and labor force involved in seeding, it is advisable to have a seeding density of 15-20 kg/ha.