• 한국초전도ㆍ저온공학회논문지
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• 제10권1호
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• pp.19-23
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• 2008

Spherical $MgB_2$ powders was synthesized with the ultrasonic spray pyrolysis(USP) process using aqueous solutions of boron and magnesium ion. The properties of synthesized $MgB_2$ powder were characterized by XRD, SEM and EDS. A small amount of MgO was detected as the secondary phase out of the synthesized powder and the ratios of $MgB_2$ to MgO increased with increasing furnace temperature. The particle size and morphology of $MgB_2$ powder were investigated with varying molar concentration of the boron and magnesium solution and furnace temperature between $600^{\circ}C$ and $1000^{\circ}C$ in $Ar/H_2$. The average particle size of $MgB_2$ showed narrow distribution ranging from 300nm to 400nm. The morphology of particles exhibited mostly spherical shapes and uniform distribution.

• Asian-Australasian Journal of Animal Sciences
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• 제18권1호
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• pp.3-7
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• 2005

The insulin-like growth factors (IGFs), their receptors, and their binding proteins play key roles in regulating cell proliferation and apoptosis. Insulin-like growth factor binding protein-3 (IGFBP3, OMIM #146732) is one of the proteins that bind to the IGFs. IGFBP3 is a modulator of IGF bioactivity, and direct growth inhibitor in the extravascular tissue compartment. We identified twenty-two novel single nucleotide polymorphisms (SNPs) in IGFBP3 gene in Korean cattle (Hanwoo, Bos taurus coreanae) by direct sequencing of full gene including -1,500 bp promoter region. Among the identified SNPs, five common SNPs were screened in 650 Korean cattle; one SNP in promoter (IGFBP3 G-854C), one in 5'UTR region (IGFBP3 G-100A), two in intron 1 (IGFBP3 G+421T, IGFBP3 T+1636A), and one in intron 2 (IGFBP3 C+3863A). The frequencies of each SNP were 0.357 (IGFBP3 G-854C), 0.472 (IGFBP3 G-100A), 0.418 (IGFBP3 G+421T), 0.363 (IGFBP3 T+1636A) and 0.226 (IGFBP3 C+3863A), respectively. Haplotypes and their frequencies were estimated by EM algorithm. Six haplotypes were constructed with five SNPs and linkage disequilibrium coefficients (|D'|) between SNP pairs were also calculated. The information on SNPs and haplotypes in IGFBP3 gene could be useful for genetic studies of this gene.

• 대한수학회논문집
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• 제35권1호
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• pp.1-12
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• 2020

A pathos block line cut-vertex graph of a tree T, written P BL_c(T), is a graph whose vertices are the blocks, cut-vertices, and paths of a pathos of T, with two vertices of P BL_c(T) adjacent whenever the corresponding blocks of T have a vertex in common or the edge lies on the corresponding path of the pathos or one corresponds to a block B_i of T and the other corresponds to a cut-vertex c_j of T such that c_j is in B_i; two distinct pathos vertices P_m and P_n of P BL_c(T) are adjacent whenever the corresponding paths of the pathos P_m(v_i, v_j) and P_n(v_k, v_l) have a common vertex. We study the properties of P BL_c(T) and present the characterization of graphs whose P BL_c(T) are planar; outerplanar; maximal outerplanar; minimally nonouterplanar; eulerian; and hamiltonian. We further show that for any tree T, the crossing number of P BL_c(T) can never be one.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
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• pp.5-8
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• 2001

The $Sr_{0.8}Bi_{2.4}Ta_{2}O_{9}(SBT)$ thin films are deposited on Pt-coated electrode$(Pt/TiO_{2}/SiO_{2}/Si)$ using RF magnetron sputtering method. With increasing annealing tempera ture from $600[^{\circ}C]$ to $850[^{\circ}C]$, Bi-layered perovskite phase was crystallized above $650[^{\circ}C]$. The dielectric constant is 213 at annealing temperature of $750[^{\circ}C]$ and dielectric loss have a stable value within 0.1. Leakage current density is $1.01{\times}10^{-8} A/cm^{2}$ at annealing temperature of $750[^{\circ}C]$ The fatigue characteristics of SBT thin films did not change up to $10^{10}$ switching cycles.

• 대한기계학회논문집
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• 제10권6호
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• pp.937-946
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• 1986

본 논문에서는 이와 같은 점을 고려하여 두께가 얇은 평면응력 상태의 CT 시 험편을 이용하여 W와 z의 변화에 따른 파괴인성치와 J저항곡선의 거동 및 크랙성장을 고려한 J적분식도 검토하였다. 또한, 재료를 변형경화 재료로 가정하고 HRR 응력변 형율장의 특성을 이용하여 컴퓨터 프로그램을 작성하여 J적분을 구한 후 실험치와 상 호 비교 검토하였다. 이 때 사용한 입력자료는 실험치의 그것과 동일하게 하였다.

• 열처리공학회지
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• 제7권1호
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• pp.25-34
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• 1994

To investigate the effect of austenitizing tempratures on the mechanical properties and corrosion resistance of 0.19%C-13.6%Cr martensitic stainless steel, the changes in martensitic trasformation temperatures, mechanical properties and anodic polarization curve were examined after changing the austenitizing temperatures and tempering temperatures. On increasing heating rate at the same austenitizing temperatures, $A_s$, $A_r$ and $M_s$ increased. And the $M_s$ temperature showed to be decreased with increasing austenitizing temperature. With increasing tempering temperature up to $500^{\circ}C$, strength, hardness and impact value were not changed remarkably, on the other hand the tensile strength and hardness decreased and impact value increased after tempering above $550^{\circ}C$ owing to the $M_{23}C_6$ carbide precipitation. The abrupt decrease in elongation at the tempering temperture of $500^{\circ}C$ proved to the precipitation of $M_7C_3$ carbide. The effect of austenitizing temperature on the mechanical properties of the tempered specimen showed to be decreased in impact value and elongation at the austenitizing temperature of $1150^{\circ}C$. At low tempering temperatures the corrosion resistance of the tempered specimen was not changed obviously with increasing tempering temperature. On the other hand, the resistance decreased above the tempering temperature of $600^{\circ}C$ due to the precipitation of $M_{23}C_6$ carbides. The corrosion resistance showed to be improved with increasing the austenitizing temperature owing to the dissolution of carbides.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권1호
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• pp.29-35
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• 2010

To compare the quality of manufactured goods distributed in the domestic markets, 6 isolates of Dongchongxiacao products, namely, 4 Paecilomyces tenuipes specimens (J2P, 901A, 901B, and 901C), 1 Cordyceps militaris specimen (901D), and 1 Cordyceps sinensis specimen (CI-1), were analyzed for their physicochemical properties and sequence-structure relationships. P. tenuipes (J2P), a kind of Dongchongxiacao, was successfully inoculated on silkworms by percutaneous infection of Rural Development AdminstraionNam et al., 1999); fruiting bodies were then formed on the complete surface of the pupa. Since P. tenuipes (J2P) from silkworm larva was also proved to have remarkable pharmacological activities, it has been produced in bulk and has been successfully sold to buyers in the Korean market. Additionally, imitation products such as 901A, 901B, 901C, 901D, and CI-1 were sold simultaneously, resulting in deterioration of product quality. This research focuses on establishing quality standards to discriminate between the original and imitation products circulating in the market. The products obtained for the experiments included J2P, 901A, 901B, 901C, 901D, and CI-1; proximate analysis was performed for these products. The hosts and methods of conidia inoculation for proliferation of mycelia differed among the products. P. tenuipes (J2P) was proliferated in live silkworm larvae, and dead silkworm pupae were used to produce 901A, 901B, and 901C. On the other hand, 901D was produced on hulled rice medium. Quality analysis of C. sinensis revealed that CI-1, which was imported from China, smelled bad and proved to be a counterfeit with the fruiting body glued to the insect by twigs. The results of the proximate analysis of 901A, 901B, 901C, and 901D were similar to those of J2P with respect to the moisture content. Otherwise, J2P contained higher crude protein than 901A, 901B, 901C, and 901D, but contained very low fat. C. militaris (901D) and C. sinensis (CI-1) had low crude protein content-12.79% and 9.78% respectively-as compared to that of J2P, which was 62.38%. In contrast to the crude ash content of 6.4% in J2P, the crude ash content of CI-1 was 18.51% and this specimen was found to contain many impurities. phylogenetic analysis of P. tenuipes revealed that the sequence similarity of J2P, 901B, and 901C was in the range of 92.3~92.7%. Additionally, differences in the sequences were found at the positions 65 bp, 436 bp, 441 bp, 463 bp, etc.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.85-85
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• 2002

Pregnancy block by male pheromones in mice differs in incidence depending on the combination of strains. Female mice of BALB/cA strain mated with BALB/cA males show a 100% pregnancy block when exposed to males of inbred strain DDK shortly after copulation (Chung et al., Biol Reprod 1997). In the present study, BALB/cA females mated with the males of other strains (CBA/J, C3H/HeN, C57BL/6Cr, and IXBL) showed higher pregnancy rates (66.6-87.5%) even when they were exposed to DDK males. In the pharmacological induction of pregnancy block with dopamine agonist (Bromocriptine, 4mg/kg BW), BALB/cA females mated with BALB/cA males showed a 100% pregnancy block. In contrast, BALB/cA females mated with CBA/J, C3H/HeN, and C57BL/6Cr males showed higher pregnancy rates (40-70%). These results suggest that the better pregnancy rate of BALB/cA females mated with alien males may be due to the stronger viability of F 1 embryos. This interpretation was confirmed by an embryo transfer experiment in which a higher implantation rate was observed when BALB/cA embryos grown in BALB/cA females exposed to BALB/cA males were transferred into recipient BALB/cA females exposed to DDK males. These results suggest that the embryonic genotype or viability of the embryo is one factor contributing to the occurrence of pregnancy block by male pheromones in mice.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.68.1-68.1
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• 2008

• 대한수학회논문집
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• 제30권2호
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• pp.65-72
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• 2015

The minimum rank mr(G) of a simple graph G is defined to be the smallest possible rank over all symmetric real matrices whose (i, j)-th entry (for $i{\neq}j$) is nonzero whenever {i, j} is an edge in G and is zero otherwise. The corona $C_n{\circ}K_t$ is obtained by joining all the vertices of the complete graph $K_t$ to each n vertex of the cycle $C_n$. For any t, we obtain an upper bound of zero forcing number of $L(C_n{\circ}K_t)$, the line graph of $C_n{\circ}K_t$, and get some bounds of $mr(L(C_n{\circ}K_t))$. Specially for t = 1, 2, we have calculated $mr(L(C_n{\circ}K_t))$ by the cut-vertex reduction method.