• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.125-132
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• 2002

This study was conducted to examine the effects of electric stimulation conditions on in vitro developmental ability of procine embryos after somatic cell nuclear transfer, The porcine ear cell was cultured in vifro for confluency in serum-starvation condition (TCM-199＋0.5% FBS) for cell confluency. The zona pellucida of IVM oocytes were partially drilled using laser system. Single somatic cell was individually transferred into the enucleated oocyte. The reconstructed embryos were electrically fused with 0.3M mannitol. After electric fusion, the embryos were activated and cultured in NCSU-23 medium containing 10% FBS at 39$^{\circ}C$, 5% $CO_2$ in air for 6 to 8 days. Nuclear transferred(NT) oocytes which fused at a field strength of 1.90kv/cm showed a higher (P<0.05) fusion rate(49.5%, 50/101) compared to 2.10 kv/cm(25.8%, 24/93) or 2.50kv/cm(30.3%, 27/89). After electric activation, the cleavage rate of NT embryos was 48.0(24/50), 66.6(16/24) and 70.3% (19/27), respectively and these were not different. There was no significant difference in fusion rate by duration and pulse of electric stimulation. In cleavage rate, however, more NT embryos(76.3%, 45/59) cleaved at 60 $\mu$sec twice than other embryos(49.1 to 56.5%) with different conditions of electric stimulation(P<0.05). NT embryos activated at a field strength of 1.50kv/cm showed a higher developmental rate(9.8%, 5/51) than those embryos activated at 1.25kv/cm(0%) or parthenotes(6.4%, 7/109). These results suggest that some factors such as field strength, duration and pulse of electric stimulation could be affected to in vitro developmental ability of nuclear transplanted porcine embryos.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.41-48
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• 2004

The objective of the CM model projects is to achieve gradually the development of Domestic Construction, Industry with function, effects, problems and improvement which are the results after assessing tills finished project on the basis of CM Plan. The result is very useful of being activated CM and giving good orders continuously. Therefore this study describes work scope, organization, performance and management process for Baekseok-Cheonan 2BL project and picks out practical problems about CM and then suggests CM technical development directions and institutional improvements.

• Journal of the Korean Society of Safety
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• v.22 no.5
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• pp.77-83
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• 2007

This study is conducted on spontaneous ignition temperature and activation energy of Hydroxypropyl Methyl Cellulose(HMC) powder. HMC is a kind of cellulose derivative and used as additives for building material, surface coating, printing ink, adhesives, cosmetics and medical supplies. So this material has been widely used as important additive in the chemical industry fields and a mount of production has increased year by year. Therefore, it is very important to find out the thermal ignition characteristics of its danger and the critical ignition temperature. This study was performed by the Spontaneous Ignition Tester(SIT) and so on. Based on the data of the SIT-II, the critical ignition point of HMC is about $186^{\circ}C$ which is slightly lower than normal cellulose.

• Journal of the Korean Professional Engineers Association
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• v.36 no.2
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• pp.50-55
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• 2003

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.292-304
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• 2023

Purpose: This study was conducted to obtain experimental data for the establishment of preventive measures against fire, as large and small fire accidents occur at production and storage sites of superabsorbent polymers developed for the convenience of daily life. Method: The sample container was fixed at 0.2m in both length and width, and was shaped into a rectangular cuboid with heights of 3cm, 5cm, 7cm, and 14cm to access an infinite flat plane. The sample container was fixed in the center of a thermostatic bath that was heated to a predetermined temperature according to a preset temperature control program. If the central temperature of the sample rose more than 20℃ above the set temperature, it was determined to have 'ignited', and if it remained similar to the set temperature, it was determined to have 'unignited'. Result: The critical autoignition temperature was calculated to be 212.5℃ for a sample container with a height of 3cm, 202.5℃ for 5cm, 192.5℃ for 7cm, and 177.5℃ for 14cm. The ignition induction time to reach the highest temperature was approximately 42hours for 3cm, 91hours for 5cm, 151hours for 7cm, and 300hours for 14cm. Conclusion:① As the size of the sample container increased, the autoignition temperature decreased and the ignition induction time to reach the highest temperature increased. ② The apparent activation energy was calculated to be 39.30kcal/mol, with a correlation of 99.5%.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.31-40
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• 2004

Ever since the CM was implanted in a domestic construction in 1996, it has been needed to take root and activate the CM system as soon as possible. Especially, the applied CM to private construction sector could be a fundamental barometer that how much changed and being advanced the construction system is This means, it is easy to apply CM to a governmental construction, yet it is hard to expect to successfully fix and activate CM for a private construction project unless they admit the necessity and validity of CM. Dongbu Corporation already acknowledged the need of CM in a private enterprise and willingly applied it to a construction sector while building Dongbu financial center, even before the CM was implanted to this country Therefore, this study suggests that the developmental direction of practical CM by examining effects and problems of the CM process.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.207-212
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• 2002

The Construction Management(CM) System in Korea is systematized both in name and reality by being prescribed in Construction Industry Act('97) and Construction Management Act('01) through various discussions considering reformation of construction industry structure and enhancement of construction technology competitiveness. Specially in the public construction works, CM Pilot Project is promoted by central government for the activation of CM system introduced for efficiency of public construction project. The promotion of Pilot Project is not only the settlement and activation of CM system but also the process to embody and diversify the CM system. Now we should develop various CM application type such as Owner type, PM type and type for private capital project in doing so. And with this efforts, we could expect that CM system should play an important role to enhance the efficiency of public construction works and should affect private construction sector.

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.37-44
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• 1987

The rates of solvolysis of $cis-[Co(en)_2Cl_2]^+$ complex have been investigated using spectrophotometric method at various pressures up to 1500 bar in several binary-aqueous mixtures(water-methyl alcohol, water-acetone, water-isopropyl alcohol and water-ethylene glycol). The activation volumes obtained from the pressure effect on rate constants were 1.13∼4.44 cm3mole-1 for methyl alcohol, 1.13∼3.59$cm^3mole^{-1}$ for acetone, 0.82∼3.44$cm^3mole^{-1}$ for isopropyl alcohol and 1.13∼2.68cm3mole-1 for ethylene glycol. In case of water-methyl alcohol, in addition to, the rates of solvolysis of this complex were determined in the presence of Fe(Ⅱ) ion and the activation volumes were -0.56∼1.59cm3mole$^{-1}$. The rates of solvolysis of this complex were analyzed by comparing with the results obtained from activation volumes and free energy cycle.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.244-256
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• 2008

The Construction Management contracting method and administration system had introduced to Korea 10 years ago. The actual CM consulting contract has adapted just for 5 years only. The CM administration system proves lots of innovative construction practices, upgrading construction industry from corporations to site operations. However, there are more tasks to the CM professionals to revitalize CM contracting methods and administration system. This research investigated what CM has achieved for the past 10 years and what CM should accomplish for the coming 10 years as future strategy and missions. Overseas CM practices are reviewed and domestic market, regulations, requirements are investigated through structured interviewed and in-depth survey to CM professionals. Many interesting issues were found through research process and those topics were categorized by industry, academy and government for defining current problems and future tasks. These issues for future strategy and mission needs to be utilized to develop future CM contracting methods and administration system. The system to follow up these meaningful results of CM is important for the future progress.

• Korean Journal of Construction Engineering and Management
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• v.21 no.6
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• pp.56-65
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• 2020

Urban renovation projects (reconstruction and redevelopment) have a longer licensing period than general housing projects, and many consultations with the licensing authorities require expertise. Most of the members of the union do not have basic knowledge of the maintenance business, so they have a lot of authority to promote smooth business Is entrusted to the union leader. However, contrary to the original purpose entrusted by the members, it is easy to find a case where the business is suspended because the union leader is exposed to corruption for the private interests of the union, and the members' disputes could not be resolved. In order to overcome this risk, the problem of the maintenance project was found through a questionnaire survey composed of practical experts, and a solution was presented through the KCSI evaluation model. This study mentioned the necessity of a responsible CM that can make independent business decisions without interference from the union, rather than a management-type CM limited to the cooperative's work assistance. In order to promote the construction industry's national role, it was necessary to revitalize responsible CM, so six practical alternatives were proposed.