• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.449-454
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• 1995

The present study was conducted to assess gene expression of bacterial lacZ driven by the SV40 promoter at early developmental stages of bovine embryos. The lacZ gene was linearized with BamHI digestion and introduced into the pronucleus by microinjection at 20 hrs after the commencement of in vitro fertilization. Intact bovine blastocysts were not stained with X-Gal, suggesting that there is no endogenous beta-galactosidase activity in these blastocysts. In contrast, the bovine blastocyst cells microinjected with the lacZ gene exerted a characteristic greenish-blue color originating from the bacterial beta-galactosidase activity, albeit at a low rate, i.e. 2.1% of the total fertilized oocytes injected. It was concluded, therefore, that the lacZ gene driven by the SV40 promoter could be used for an indirect screening method in which the presence of transgene is evaluated from the product of transgene expression.

• Journal of the Korean Mathematical Society
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• v.57 no.2
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• pp.283-312
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• 2020

A sufficient condition for an Artinian complete intersection quotient S = 𝕜[x, y]/(x^m, yⁿ), where 𝕜 is an algebraically closed field of a prime characteristic, to have the strong Lefschetz property (SLP) was proved by S. B. Glasby, C. E. Praezer, and B. Xia in [3]. In contrast, we find a necessary and sufficient condition on m, n satisfying 3 ≤ m ≤ n and p > 2m-3 for S to fail to have the SLP. Moreover we find the Jordan types for S failing to have SLP for m ≤ n and m = 3, 4.

• Solar Energy
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• v.18 no.3
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• pp.205-215
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• 1998

Entrainment in thermosyphons and heat pipes was characterized in view of the interfacial stability associated with the critical Weber number and the entrainment limit at the onset of liquid entrainment from the liquid or wicked interface. Both literature review and theoretical analysis on the entrainment models were peformed in order to evaluate accuracy of the predicted value. For this purpose, the models were categorized in two groups according to their entrainment mechanism and interfacial configurations, i.e., the wave-induced entrainment and the shear-induced entrainment, respectively. Thus, the twelve models(five models for the wave-induced entrainment and seven for the shear induced entrainment) were examined to obtain individual trends and their discrepancies from the general tendency of the overall models. As a result, the critical Weber numbers and entrainment limits were calculated and represented as a function of vapor temperature for the chosen characteristic dimensions of the interface.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.118-121
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• 1999

PLZT thin films were fabricated with different energy density by pulsed laser deposition. PLZT films deposited on Pt/Ti/SiO$_2$/Sr substrate. This PLZT thin films of 5000$\AA$ thickness were crystallized at $600^{\circ}C$, 200mTorr $O_2$ pressure for 2 J/$\textrm{cm}^2$ laser energy density. 14/50/50 PLZT thin film showed a maximum dielectric constant value of $\varepsilon$$_{r}$=1289.9 P-E hysteresis loop of 14/ 50/50 PLZT thin film was slim ferroelectric. Leakage current density of 14/50/50 PLZT thin film was 10/ sup -7/=A/$\textrm{cm}^2$.>.

• Proceedings of the KIEE Conference
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• summer
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• pp.1288-1290
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• 2004

Fluorescent lamp ballast using piezoelectric transformer were fabricated and its characteristic was investigated. Traditional electronic ballast is composed of basic blocks, which are composed of rectifier, power factor corrector and resonant inverter fluorescent lamp. The proposed electronic ballast has several advantages accordingly, traditional ballast was replaced fabricated electronic ballast using piezo electronic transformer and VCO oscillated, because of its lighter weight, high efficiency and saving energy.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1187-1189
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• 2003

With development of Circuit technology, accuracy of dielectric or induction healing apparatus was developed. This study aims at realization of food insecticidal apparatus using dielectric heating. Equipment to measure gram's permittivity or vermin's permittivity and expectation for heating temperature by computer simulation is necessary for construction of the system. And the effect of extermination of vermin for food was confirmed by experiment using the system.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.106-108
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• 2008

This paper describes output characteristics analysis of outage and phase jump generator for microgrid. The outage and phase jump can be generated with 3-phase voltage disturbance generator. As soon as the outage occurs the STS(Solid Transfer Switch)s are switched off. At the beginning of the outage the PCS is required to limit the reverse current within the rated PCS output current. In case of phase jump the PCS output voltage phase should be adjusted. The generator output characteristics are analysed through simulation.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.621-623
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• 1993

This paper describes the research in condenser cone of sealing-end for 154kV oil-filled underground cable. We conducted the design based on the results of electric field analysis by electrostatics theory and FEM. In case that condenser cone type EB-A was compared with bell mouth type EB-A, the results of the AC and lightening impulse voltage test showed improvment of 10 percents.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.576-578
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• 2003

Hyperspectral image divides VNIR region to over 200 bands which can show continuous spectrum with 10 nm spectral resolution. This property is useful in geology where a spectral feature which is decided by chemical compositions and crystalline structures is recorded well. While this field has been studied variously in foreign countries, the studies are in the early stage in Korea. In this study, characteristic materials associated with AMD were classified by using EO-1 HYPERION data which is a spaceborne hyperspectral image and topographical map and DEM and geochemical map were analyzed in conjunction with the image in order to examine that classified minerals are secondary minerals by AMD.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.585-588
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• 2005

The dissolution characteristic of metal shows the different tendency according to the applied electrical potential, the kind of electrolyte and pH value, etc. In the micro electrochemical machining (ECM), unfavorable oxide/passive layer formation and overall corrosion of electrodes must be prevented. The anodic polarization curve of nickel has distinct three dissolution regions, i.e. two active regions and the transpassive dissolution region. In this paper, the stable electrode potentials of workpiece and tool were determined in sulfuric acid and hydrochloric acid solution, respectively. In each solution, different machining property was shown and possible electrochemical reactions were discussed. On the basis of this experiment, the methodology to obtain the proper electrode potential was suggested.