• Proceedings of the KSME Conference
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• 2001.06e
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• pp.613-618
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• 2001

For the evaluation of operability of MOV(Motor Operated Valve), the precision prediction of thrust/torque acting on the valve is important. In this paper, the analytical prediction method of thrust/torque was proposed. The design basis stem thrust calculation typically considers the followings: Packing thrust, Stem rejection load, design basis differential pressure load. In general, test results show that temperature, pressure, fluid type, and differential pressure, independently and combination, all have an effect on the friction factor. The prediction results of thrust/torque are well agrement with dynamic test results.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.167-170
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• 2000

The flexural vibration of a sandwich beam with partially inserted viscoelastic layer has been studied using the finite element analysis in combination with an experiment. Effects of length and thickness of partial viscoelastic layers on system loss factor(${\eta}_s$) and resonant frequency(${\omega}_r$) were considerably large. The thicker the viscoelastic layer in a sandwich beam, the larger the system loss factor in Mode 1 as compared with that in Mode 2. The loss factor increased almost linearly with increasing the length of partial viscoelastic layer. Effects of thickness of beams were also considered.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.19-22
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• 2001

This paper proposes a double cantilever sandwich-beam method for evaluating the frequency dependence of material dynamic characteristics. The flexural vibration of a double cantilever sandwich-beam specimen with a partially inserted rubber layer was studied using a finite element simulation in combination with the sine-sweep test. Quadratic relationships of dynamic elastic modulus and material loss factor of rubbers with frequency were quantitatively suggested employing the least square error method.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.797-803
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• 2001

The on-line cure monitoring of fiber reinforced thermosetting resin matrix composite material was performed for the better quality and productivity during manufacturing. Since the dissipation factor measured by dielectrometry method is dependent on the degree of cure and temperature of resin, in this study, a new method to obtain the degree of cure during on-line cure monitoring for glass/polyester composites was developed by employing a combination function of the temperature and the dissipation factor. Two sensor signals from a K-type thermocouple and an interdigitated dielectric sensor were processed during curing process under various cure cycles. The DSC (Differential Scanning Calorimetry) data was also used for the reference of degree of cure.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.129-138
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• 2010

For the fractional factorial designs, the resolution-IV designs can be used when we want to estimate the main effects and to investigate the structure of the non-negligible two-factor interaction effects, when the three-factor and higher order interaction effects are all negligible. However we need to add the additional treatment combination in order to identify the influential interactions for the resolution-IV fracrtional factorial designs. In this paper we investigate the statistical structure for 3-level resolution-IV designs constructed by fold-over scheme and introduce a method for analyzing the influential two-factor interactions.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.9-16
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• 2000

For aerodynamic design of missile bodies of non-circular cross-section, the combination of the slender body theory and the cross-flow analogy can hardly be applied owing to the lack of experimental data. An alternative is to utilize the Euler solution in the design stage. For enhanced accuracy, however, an adequate viscous correction is necessary to the Euler solution. In this work, such a procedure is examined to compensate the viscous effect by utilizing the concept of proportionality factor in cross-flow analogy. Predictions of aerodynamic coefficients combining the Euler solution and the viscous correction via proportionality factor are made for a missile body of elliptic cross-section. Results indicate that the present approach can be adopted in designing missile bodies of non-circular cross-sections.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.201-206
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• 2004

Vascular endothelial growth factor (VEGF), plays a key role in angiogenesis. Many endogenous factors can affect angiogenesis in endothelial cells. VEGF is known to be a strong migration, sprouting, survival, and proliferation factor for endothelial cells during angiogenesis in endothelial cells. Searching for novel genes involved in VEGF signaling during angiogenesis, we carried out differential display polymerase chain reaction on RNA from VEGF-stimulated human umbilical vein endothelial cells (HUVECs). In this study, follistatin (FS) differentially expressed in VEGF-treated HUVECs, compared with controls. Addition of VEGF (10ng/L) produced an approximately 11.8-fold increase of FS mRNA. F5 or VEGF produced approximately 1.8- or 2.9-fold increases, respectively, in matrix metalloproteinase-2 (MMP-2) secretion for 12h, compared to the addition of a control buffer. We suggest that VEGF may affect the angiogenic effect of HUVECs, through a combination of the direct effects of VEGF itself, and the indirect effects mediated via induction of FS in vitro.

• Journal of Korean Society for Quality Management
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• v.37 no.4
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• pp.43-51
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• 2009

This study was designed to analyze the relationship of process quality, result quality and management performance in Korean insurance industry. For this study the linkage scheme of service quality concept is used on PZB model and BSC(Balances Score Card) system. In the linkage model, the 5 service qualitry factors used in PZB model are used as the result quality variables, and internal process factor, learning/growth factor in BSC are used the process quality variables affecting the result quality variables. And also customer satisfation factor and financial performance index are used as the management performance variables. In the ivsurance industry, the process quality variables were verified to meaningfully affect the result quality variables, and the result service quality variables were verified to affect the management performance indices. As the result, the process quality and the service quality must be emhanced for the competitiveness of Korean insurance industry.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.6991-6996
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• 2015

In the past decade, the incidence and mortality rates of cholangiocarcinoma (CCA) have been increasing worldwide. The relatively low responsiveness of CCA to conventional chemotherapy leads to poor overall survival. Recently, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL or Apo2L) has emerged as the most promising anti-cancer therapeutic agent since it is able to selectively induce apoptosis of tumor cells but not normal cells. In this study, we aimed to investigate the therapeutic effect of TRAIL in CCA cell lines (M213, M214 and KKU100) compared with the immortal biliary cell line, MMNK1, either alone or in combination with a subtoxic dose of 5-fluorouracil (5-FU). We found that recombinant human TRAIL (rhTRAIL) was a potential agent which significantly inhibited cell proliferation and mediated caspase activities (caspases 8, 9 and 3/7) and apoptosis of CCA cells. The combined treatment of rhTRAIL and 5-FU effectively enhanced inhibition of CCA cell growth with a smaller effect on MMNK1. Our finding suggests TRAIL to be a novel anti-cancer therapeutic agent and advantage of its combination with a conventional chemotherapeutic drug for effective treatment of CCA.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.788-795
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• 2009

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis under various physiological and pathological conditions. We found that the VEGF isoforms VEGF120, VEGF164, and VEGF188 were expressed in the bovine mammary gland and bovine mammary epithelial cells (bMECs). Expression of VEGF in the mammary gland was significantly higher during the lactation period than during the dry period. Although dexamethasone or prolactin alone had little effect on the expression of VEGF, that in dexamethasone-treated cells was significantly induced after additional treatment with prolactin. Furthermore, the VEGF expression induced by the combination of dexamethasone and prolactin was reduced by PD98059 in a dose-dependent manner. This combination also stimulated the phosphorylation of p44/p42 MAP kinase in these cells. These results strongly suggest that the combination of dexamethasone and prolactin stimulates VEGF expression in bMECs via p44/p42 MAP kinase.