• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.314-314
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• 2010

The SiC-$ZrB_2$ composites were fabricated by combining 40vol.% of Zirconium Diboride(hereafter, $ZrB_2$) powders with Silicon Carbide(hereafter, SiC) matrix. TheSiC+40vol.%$ZrB_2$ composites were manufactured through Spark Plasma Sintering(hereafter, SPS) under argon atmosphere, uniaxial pressure of 50MPa, heating rate of $100^{\circ}C$/min, sintering temperature of $1,500^{\circ}C$ and holding time of 5min. But one on/off pulse sequence(one pulse time: 2.78ms) is 10:9(hereafter, SZ10), and the other is 48:8(hereafter, SZ48). The physical and mechanical properties of the SZ12 and SZ48 were examined. Reactions between $\beta$-SiC and $ZrB_2$ were not observed via X-Ray Diffraction(hereafter, XRD) analysis. The apparent porosity of the SZ10 and SZ48 composites were 9.7455 and 12.2766%, respectively. The SZ10 composite, 593.87MPa, had higher flexural strength than the SZ48 composite, 324.78MPa, at room temperature. The electrical properties of the SiC-$ZrB_2$ composites had Positive Temperature Coefficient Resistance(hereafter, PTCR).

• Korean Management Science Review
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• v.32 no.4
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• pp.135-153
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• 2015

In this paper, we intend to understand distinguishable SNS technology contributions for B2C commerce. In order to theorize this, we draw upon Technology-to-Performance chain (TPC) theory to develop the model that could explain how the technology value of the SNS could be realizable. For the purpose of capturing SNS technology effect to B2C channel effectiveness, on the basis of TPC theory, personal productivity is selected as a performance variable instead of satisfaction from SNS usage. Accordingly, as the antecedents of personal productivity, two variables of locatability and timeliness are extracted to reflect Task-technology-fit (TTF) dimension of performance precursors. For the utilization dimension of TPC framework, convenience and recreation tendency of the personal traits in shopping are included as the precursors of SNS utilization in the sense of reflecting utilitarian and hedonic value of SNS adoption. Empirical validation is conducted with reference to promotion and sales event on Facebook, which is chosen as the typical SNS based B2C commerce scenario. The data analysis result provide useful insights to further investigate the firm's SNS usage potentials for business applications.

• Toxicological Research
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• v.8 no.2
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• pp.331-342
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• 1992

The chicken major histocompatibility complex (MHC), the B complex, is beginning to be analyzed at the DNA level. Inbred lines of chickens have been reported to possess 3~5 MHC class II genes. To further analyzed the molecular structure of the chicken MHC class II genes, cDNA clones coding for chicken MHC class II (B-L) ${\beta}$ chain molecules were isolated from chicken spleen and liver. Tissue-specific transcription of B-L ${\beta}$genes was studied by Northern blot analysis. A high level of expression was detected for spleen poly(A)$^+$ RNA whereas a faint signal was detected for liver poly(A)$^+$ RNA. Twenty-nine cDNA clones were isolated from the spleen and eight cDNA clones were isolated from the liver. Based on restriction maps, most clones could be clustered into one family of genes. Four cDNA clones were sequenced (S7, S10 and S19 from the spleen and L1, which was identical to S19, from the liver). Complete amino acid sequences of B-L ${\beta}$ chain molecules were predicated from the nucleotide sequences of the cDNA clones. Although both the nature and the location of the conserved residues were similar in chicken and mammalian sequences, some species-specific differences were found, suggesting that the structures of the B-L molecules are similar, but not identical to their mammalian counterparts.

• Archives of Pharmacal Research
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• v.27 no.10
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• pp.1073-1079
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• 2004

Interactions of the cell adhesion molecules are known to play important roles in mediating inflammation. The proinflammatory cytokine, tumor necrosis factor-${\alpha}$(TNF-${\alpha}$), activates the NF-kB signaling pathway, which induces the expression of various genes, such as intercellular adhesion molecule-1 (ICAM-1). In this study, the effect of vitamin C on the ICAM-1 expression induced by TNF-${\alpha}$ in a human neuroblastoma cell line, SK-N-SH was investigated. Treatment with vitamin C resulted in the downregulation of the TNF-${\alpha}$-induced surface expression and ICAM-1 mRNA levels in a concentration-dependent manner. Moreover, a gel shift analysis indicated that vitamin C dose-dependently inhibited the NF-kB activation and IkB${\alpha}$ degradation induced by TNF-${\alpha}$. Taken together, these results suggest that vitamin C downregulates TNF-${\alpha}$- induced ICAM-1 expression via the inhibition of NF-kB activation.

• The Korea Journal of Herbology
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• v.36 no.4
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• pp.41-50
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• 2021

Objectives : This study is to check the quality of Moschus products in Korean markets using a chromatographic analysis. Methods : We collected musk products, two genuine products from Russia (A, B), two authentic products from Hong Kong (C) and Korea (D), the Ministry of Food and Drug Safety (MFDS) standard (E), and two fire ants products (E, F). Results : For identification, TLC analysis of 60% ethanol extracts of each product showed that A, B, C, and E have the suitable patterns before color development at 365 nm UV light for the MFDS regulation in Korea. A clear red spot was observed from the E at R_f 0.6 with 365 nm UV light after color development, but this spot was not found in A and B. For the purity test, a distinct violet spot with R_f 0.87 was observed from the A and B in TLC analysis of methanol extracts of each product at white light, however, this spot was not matched with the impurities of E and F. In HPLC-UV pattern analysis, a similar peak pattern was shown in A, B and E, and similar peaks were observed C, although the similarity was weaker than that of A, B, and E. The F and G showed different peak patterns compared with the peak patterns of other samples. Conclusions : Hence, it is considered that the test methods need flexibility in application for identification and purity test depending on the type of sample.

• Journal of Powder Materials
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• v.17 no.2
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• pp.154-159
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• 2010

In this study, the sintering behavior of (Nd, Dy)-Fe-B powder which fabricated by strip-casting was investigated with various sintering temperatures and holding times. The relative density over 99% could be obtained by both sintering at $1070^{\circ}C$ for 1h and sintering at $970^{\circ}C$ for 20h. The grain growth was observed in sintered specimen at $1050^{\circ}C$ compared to one at $970^{\circ}C$. The isothermal sintering process below $1000^{\circ}C$ led to suppress grain growth showing the improved magnetic properties. The phase transformation of Nd-rich was confirmed by X-ray diffraction pattern.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.473-474
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• 2006

Boron Phosphide films were deposited on (111) Si substrate at $650^{\circ}C$, by the reaction of B2H6 with PH3 using APCVD. N2 was carried out as carrier gas. The optimal gas rates were $20\;m{\ell}/min$ for B2H6, $60\;m{\ell}/min$ for PH3 and $1\;{\ell}/min$ for N2. After as grown the films were insitu annealed for 1hour in N2 ambient at $550^{\circ}C$ and measured. The measurement of AFM shows that the RMS is $29.626{\AA}$ for the reaction temperature at $650^{\circ}C$. The measurement of XRD shows that the films have the orientation of (101). Also, the measurement of AES is shown that the films have B13P2 stoichiometry.

• The Korean Journal of Food And Nutrition
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• v.22 no.3
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• pp.402-408
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• 2009

The study assessed the quality characteristics of Sulgiddeok with self-made and commercially-available rice flours during a 1-day storage at ambient temperature($20\sim22^{\circ}C$). The nutritional components, color value, physical tests, internal structure as revealed by scanning electron microscopy SEM, and sensory evaluation of Sulgiddeok were determined. Sulgiddeok prepared with self-made rice flour and two commercial rice flour were designated as sample A, B, and C, respectively. Moisture content, crude protein, crude lipid, and pH did not differ significantly among the preparations. Sweetness was highest in sample B(p<0.01) and crude ash was highest in sample A(p<0.001). L color, a value, and b value was highest in sample B, C, and C, respectively. Texture property analysis showed that hardness, gumminess, and chewiness tended to decrease during the 1-day storage, while adhesiveness, springiness, and cohesiveness tended to increase. Sensory characteristics of color, flavor, chewiness, gumminess, externals, and overall quality of sample A were superior to samples B and C. However, softness was highest in sample B. The internal structure of Sulgiddeok was preserved in sample A. It is concluded that rice flour B can make Sulgiddeok comparable to that prepared using self-made rice flour.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.1
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• pp.72-82
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• 2017

Sharing economy is expected to grow high with the notable development of Internet technology. Despite this importance, however, existing studies so far have addressed the consumers for the services of sharing economy in limited perspectives and have not properly considered the recent advent of technology. Especially, car sharing service is one of the cases that have been changed rapidly with growth of the Internet technology. In this sense, the present study focuses on car sharing service and analyzes the effects of its service factors on consumers' attitude and intention to use. In addition, we examine differences in such effects between two types of services, business to customer (B2C) and customer to customer (C2C). Based on the analysis results, we discuss the guidelines for successful development of services in sharing economy.

• Progress in Superconductivity and Cryogenics
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• v.19 no.1
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• pp.36-41
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• 2017

The effects of $MgB_4$ addition on the superconducting properties and the microstructure of in situ processed $MgB_2$ bulk superconductors were studied. $MgB_4$ powder of 1-20 wt.% was mixed with (Mg + 2B) powder and then pressed into pellets. The pellets of (Mg + 2B + $xMgB_4$) were heat-treated at $650^{\circ}C$ for 1 h in flowing argon. The powder X-ray diffraction (XRD) analysis for the heat-treated samples showed that the major formed phase in all samples was $MgB_2$ and the minor phases were $MgB_4$ and MgO. The full width at half maximum (FWHM) values showed that the grain size of $MgB_2$ decreased as the amount of $MgB_4$ addition increased. $MgB_4$ particles included in a $MgB_2$ matrix is considered to suppress the grain growth of $MgB_2$. The onset temperatures ($T_{c,onset}$) of $MgB_2$ with $MgB_4$ addition (0-10 wt.%) was between 37-38 K. The 20 wt.% $MgB_4$ addition slightly reduced the $T_{c,onset}$ of $MgB_2$ to 36.5 K. This result indicates that $MgB_4$ addition did not influence the superconducting transition temperature ($T_c$) of $MgB_2$ significantly. On the other hand, the small additions of 1-5 wt.% $MgB_4$ increased the critical current density ($J_c$) of $MgB_2$. The $J_c$ enhancement by $MgB_4$ addition is attributed not only to the grain size refinement but also to the possible flux pinning of $MgB_4$ particles dispersed in a $MgB_2$ matrix.