• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.277-281
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• 2003

Effects of $CaF_2$ addition as a filler on the high frequency dielectric properties and sintering of CaO-$Al_2O_3-SiO_2-B_2O_3$(CASB) and ZnO-MgO-$B_2O_3-SiO_2$(ZMBS) glass composites were investigated. The optimal glass composition in the CASB system was 33.0CaO-$17.0Al_2O_3-35.0SiO_2-15.0B_O_3$(in wt%). The corresponding dielectric properties were k=8.1 and $Q{\times}fo$=1,200GHz. The sintering temperature was $800{\mu}m$. In case of 2MBS system, 25.0ZnO-25.0MgO-20.0$B_2O_3-30.0SiO_2$(in wt%) glass showed k=6.8 and $Q{\times}fo$=5,200GHz when it was sintered at $750^{\circ}C$. The maximum amount of $CaF_2$ in the CASB and 2MBS glass system without any detrimental effect on the sintering was 25.0 v/o and 15.0 v/o, respectively. The addition of $CaF_2$ in the glass systems improved the high frequency dielectric properties. In case of CASB+$CaF_2$ composite, k was 7.1 and $Q{\times}fo$ was 2,300GHz. And in case of 2MBS+$CaF_2$ composite, k was 5.9 and $Q{\times}fo$ was 8,100GHz. $CaF_2$ addition also reduced sintering temperature. Effects of $CaF_2$ on the dielectric and sintering properties was analyzed in terms of viscosity and crystallization behavior changes due to the interaction between $CaF_2$ and the glass systems.

• Journal of the Korean Electrochemical Society
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• v.3 no.4
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• pp.241-245
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• 2000

The objective of this work Is to design, fabricate, and characterize pseudo-capacitor using amorphous $MnO_2\;nH_2O$ electrode material. The cyclic voltammogram under 100mV/s scan rate of the material shows the electrochemically stable potential window of 1V and the specific capacitance of 250F/g. The TDMA pulse test result indicates that the TDMA system (2 parallel-pseudo-capacitor systems) has the ohmic voltage drop of 0.22V and the capacitor voltage drop of 0.38V. The total voltage drop of the TDMA system is 0.60V and less than 1V of which value is the maximum voltage drop requirement or the TDMA satellite phone. Also, the TDMA system had the ESR of $55m{\Omega}$ and the capacitance of 105mF. Therefore, it is confirmed that the TDMA system has the application feasibility as load-leveling capacitor for the satellite phone.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.25-29
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• 2003

This study was carried out to investigate a usefulness of the microsatellite DNA markers for parentage verification of Thoroughbred (TB) horses. 9 TB horses samples were genotyped for nine international minimum standard markers (AHT4, 5, ASB2, HMS3, 6, 7, HTG4, 10, and VHL20), and the additional panel of four markers, ASB17, CA425, LEX33, and TKY321. This methods consisted of multiplexing PCR procedures, and it showed reasonable amplification of all PCR products. Genotyping was performed with an ABI 310 genetic analyzer. Foal I was excluded according to principles of Mendelian genetics in AHT4 (H/K), ASB2 (Q/Q), HMS3 (I/P), HTG4 (M/O), HTG1O (K/R), VHL20 (M/P), ASB17 (F/N), LEX33 (M/O), and TKY321 (G/I) markets. Foal II was excluded with markers AHT5 (K/M), ASB2 (M/N), HMS7 (N/N), HTG1O (K/K), VHL20 (I/I), ASB17 (F/F) and TKY321 (G/I). Foal III was excluded with markers AHT4 (O/O), AHT5 (K/K), ASB2 (M/R), HMS6 (M/P), HMS7 (O/O), HTG10 (R/S), VHL20 (L/M), and ASB17 (N/O). These results suggest that the present DNA typing is so useful for parentage verification of TB horses.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.2-2
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• 1999

본 연구에서는 액체 로켓용 추진제 분사기로 많이 활용되는 충돌형 분사기중에서 2중 충돌(F-O-O-F)형 분사기에 대한 미립화 특성을 파악하였다. 액적의 크기를 측정하기 위하여 위상/도플러 입자분석기를 사용하였으며, 모의 추진제로 물을 사용하였다. 모의 추진제의 운동량비와 압력 강하량 변화에 따른 2중 충돌(F-O-O-F)형 분사기의 미립화 특성과 크기분포에 대하여 고찰하였다. 분사기 면으로부터 100mm 떨어진 단면에서 산화제/연료의 운동량비가 MR=1.19에서 MR=6.48까지 증가함에 따라 액적크기(SMD)는 감소하였으며, 액적크기(SMD)가 운동량비(MR)에 대하여 SMD= 193.480+15.687MR-5.036M$R^2$+0.415MR$^3$와 같은 관계식에 근사되었다 또한, 연료와 산화제의 압력강하량이 증가할수록 액적크기(SMD)가 감소하였다. 충돌 분무유동장의 액적크기 분포는 Rosin-Rammler 분포함수와 Upper-limit분포함수 모두에 대하여 잘 일치하고 있다. 본 연구의 결과는 액체 로켓용 충돌형 분사기의 초기 설계단계에서 유용하게 사용될 수 있을 것이다.

• Journal of the Korean Mathematical Society
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• v.55 no.3
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• pp.553-574
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• 2018

In this paper, we study harmonic maps and biharmonic maps on the principal G-bundle in Kobayashi and Nomizu and also the warped product $P=M{\times}_fF$ for a $C^{\infty}$(M) function f on M studied by Bishop and O'Neill, and Ejiri.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.251-254
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• 2001

This paper describes an efficiency improvement of buried contact solar cell (BSCS) with a structure of MgF$_2$/CeO$_2$/Ag/Cu/Ni grid/n$^{+}$ emitter/p-type Si base/p$^{+}$/Al. Theoretical and experimental investigations were performed on a double layer antireflection (DLAR) coating of MgF$_2$/CeO$_2$. We investigated CeO$_2$ films as an AR layer because they have a proper refractive index of 2.46 and demonstrate the same lattice constant as Si substrate. An optimized DLAR coating shewed a reflectance as low as 2.04 % in the wavelengths ranged from 0.4 ${\mu}{\textrm}{m}$ to 1.1 ${\mu}{\textrm}{m}$. BCSC cell efficiency was improved from 16.2 % without any AR coating to 19.9 % by employing DLAR coatings. Further details on MgF$_2$/CeO$_2$ DLAR coatings on the BCSC cells are presented in this paper.per.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.152-156
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• 2001

This study was conducted to investigate the flower organ removal effect on Atractylodes macrocephala Koidz which was introduced from China. The results were summarized as follows; The plant height of Flower Organ Cutting(F.O.N.C.) treatment short by 1.7∼2.5 cm compared to Flower Organ Non-Cutting(F.O.N.C.) treatment. But number of stem and stem diameter of F.0.C treatment were similar to that of F.O.N.C. treatment. The fresh weight of above-ground part of F.O.N.C. treatment was decreased 48∼60% compare to F.O.C. treatments. The later was period of F.O.C., the higher was fresh weight of above-ground part. The growth of underground part was more F.O.C. at July 15 and Aug. 20 treatments than F.O.N.D treatment. The dry rhizome yield of F.O.C. at July 15 treatment was increased 40% compare to F.O.N.D treatment. Essential oil content of F.O.C. at July 15 treatment was increased 12% compare to F.O.N.D treatment.

• Bulletin of the Korean Mathematical Society
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• v.38 no.3
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• pp.487-493
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• 2001

$Let \Omega$ be a bounded convex domain in C^n$ with smooth boundary. Let M be a subvariety of $\Omega$ which intersects $\partial$$\Omega$ transversally. Suppose that $\Omega$ is totally convex at any point of $\partial$M in the complex tangential directions.For f $\epsilon$O(M)$\bigcap$/TEX>$C^{\infty}$($\overline{M}$/TEX>), there exists F $\epsilon$ o ($\Omega$))$\bigcap$/TEX>$C^{\infty}$($\overline{\Omega}$/TEX>) such that F(z) = f(z) for z $\epsilon$ M.

• Journal of Life Science
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• v.13 no.4
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• pp.412-415
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• 2003

The purpose of this present study was to investigate the polymorphism of esterase locus for individual identification and parentage verification in Jeju native horse (JNH). Seventy three random JNH samples were studied by polyacrylamide gel isoelectric focusing(IEF) at pH 3.5 ∼ 6.0. We detected international recognized alleles, F, G, H, I, M, and an silent allele $I^o$. Gene frequencies of allele I showed 0.479 the highest, while allele H and M($I^o$) with relatively low frequencies were 0.027 and 0.014, respectively.

• Bulletin of the Korean Mathematical Society
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• v.33 no.3
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• pp.487-496
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• 1996

Let f(z) be an entire function. Then the order $\rho(f)$ of f is defined by $$ \rho(f) = \overline{lim}_r\to\infty \frac{log r}{log^+ T(r,f)} = \overline{lim}_r\to\infty \frac{log r}{log^+ log^+ M(r,f)}, $$ where T(r,f) is the Nevanlinna characteristic of f (see [4]), $M(r,f) = max_{$\mid$z$\mid$=r} $\mid$f(z)$\mid$$ and $log^+ t = max(log t, 0)$.