• Korean Journal of Animal Reproduction
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• v.22 no.3
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• pp.277-286
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• 1998

The effect of MAP kinase activity on maturation of porcine oocytes was investigated. MAP kinase was detected by immunofluorescence staining in nucleus of oocytes just before entering GVBD (germinal vesicle breakdown)stage. In a Western blot with GV (germinal vesicle) from these oocytes (cultured for 25 hours), a shift of MAP kinase band a, pp.ared, suggesting an activated stage of the kinase. No activity was shown in the blot with GV isolated from, oocytes cultured for 0 hour. To confirm that activation of MAP kinase induce GVBD, we microinjected MAP kinase purified from matured oocytes starfish into the cytoplasm of oocytes in GV stage (cultured for 0 hour). The injected MAP kinase did not cause early a, pp.arance of GVBD. No oocytes showed GVBD state until 20 hours of culture. Activity of MAP kinase did not increase significantly after the injection. When the exogenous MAP kinase was injected into GV, GVBD was induced in about 20% of oocytes cultured for 5 to 10 hours. These results suggest that MAP kinase is traslocated to nucleus and function as a factor inducing GVBD.

• Transactions of the Society of Information Storage Systems
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• v.10 no.1
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• pp.27-31
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• 2014

Optical Archive system consists of cartridge, drive and transfer robot. Transfer robot moves disc in cartridge to drive that reads data of disc. Distance between disc in cartridge and transfer robot very short, about 4mm. When disc projects, there is a danger of collision. Collision can cause breakage of disc and breakdown of system. To prevent collision of disc and transfer robot, projection of disc should be detected. In this paper, we proposed error monitoring method of projecting disc in archive data storage using camera. Proposed algorithm is evaluated by experiments with archive system.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.813-816
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• 1988

This study is to investigate the adhesive strength of composite material's interface on the experimental methode of tree growth in the material. The results are as follows 1) The irradiations of ultrasonic energy cause the mechanical vibration in the polymer composite materials of fluid state, so then bring about physical dispersion and heat for inorganic materials, being supposed to produce chemical interlinking reaction, decreasing of voids between filler and matrix. 2) As the intensity of ultrasonic energy and its irradiated time are larger, the tree inception and breakdown voltages increase and the tree growing is slower. so we obtain that the interface adhesive force can be strengthened by the irradiation of ultrasonic energy.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1684-1686
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• 1998

Gas Insulated Switchgear(GIS) acts as an indispensible part in power transmission network. In order that GIS may have its high reliability, it is necessary to pay careful attention to its whole process e.g., designing, manufacturing, installation, and operation. The main hazard in GIS comes from free conducting particles, which can move and cause breakdown under the influence of the electric field. Although the concentration on protecting the GIS inner part against the free conducting particles is made, it is, actually, almost impossible to avoid the hazard from the particles throughly. In this paper, using the EHV test chamber, partial discharge quantity in GIS was measured when free conducting particles initiate to discharge for providing fundamental data for the purpose of developing predictive diagnosis technology on site GIS.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1711-1713
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• 1998

This paper describes the insulation characteristics of GIS by the free conducting particles under alternating voltage. The particles of the GIS can cause decrease in breakdown voltages. Various materials and sizes of free conducting particles were used to study the lift-off and fall-down characteristics. The measured lift-off voltage for copper particle agreed with the calculated one.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.100-102
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• 1994

VCB, with its big arc extinction in very short switching time, produces the high switching surge voltage which may cause the breakdown of motor insulation or acceleration of insulation deterionation. To protect motor winding insulation, we developed the computer algorithm for simulating the surge occurred in VCB by EMTP. And we established the effect of the C-R surge absorber by the surge measurement in the motor-VCB circuit.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1801-1803
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• 1997

The Gas Insulated Switchgear(GIS) has made it an indispensible part of power transmission network. In order that the GIS may have its high reliability, it is necessary to pay careful attention to its whole process e.g., designing, manufacturing, installation, and operation. The main hazard in GIS comes from free conducting particles, which can move and cause breakdown under the influence of the electric field. Although the concentration on protecting the GIS inner part against the free conducting particles is made, it is, actually, almost impossible to avoid the hazard from the particles throughly. In this paper, the corona discharge in GIS initiated by the free conducting particles was discribed through laboratorial experiment The magnitude of the corona discharge voltage was measured using current measuring method by the impedance. The purpose of this experiment is to get fundamental data which is essential to develop GIS diagnosis technology.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.3
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• pp.167-171
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• 2014

This paper examines the destruction behavior of NPN BJT (bipolar junction transistor) by repetition pulse. The injected pulse has a rise time of 1 ns and the maximum peak voltage of 2 kV. Pulse was injected into the base of transistor. Transistor was destroyed, current flows even when the base power is turned off. Cause the destruction of the transistor is damaged by heat. Breakdown voltage of the transistor is 975 V at single pulse, and repetition pulse is 525~575 V. Pulse repetition rate increases, the DT (destruction threshold) is reduced. Pulse Repetition rate is high, level of transistor destruction is more serious.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.5
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• pp.761-769
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• 1994

VCB (Vacuum Circuit Breaker), with the strong arc extinction capability in switching the source of an induction motor, occurs the severe switching surge voltage which can cause the breakdown or the deterioration of motor insulation. Therefore, a method which reduces surge voltage across motor windings is necessary. So, it is analyzed that fast-rise-time surges resulting from VCB switching operations give rise to severe voltage stress on turn insulation. Additionally, the switching surge simulation algorithms using EMTP are developed, and C, R values of surge suppressor minimizing the steep-fronted stress in winding insulation surges are calculated.

• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.53-55
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• 2005

Because of the continuous growth of energy consumption and also the tendency to site power lines and pipelines along the same route, the close proximity of power lines and buried metallic pipelines has become more and more frequent. The lightning strokes collected by an electric substation or power line tower might cause arcing through the soil to an adjacent gas pipeline. This paper gives the review of the breakdown mechanism and the standards of separation distance between lower and pipelines.