• Journal of information and communication convergence engineering
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• v.1 no.4
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• pp.213-216
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• 2003

A VPN is widely used in a communications environment which access is controlled to permit peer connections only within a defined community of interest. It is constructed through some form of partitioning of a common underlying communication medium, where this underlying communications medium provides services to the network on a non-exclusive basis. In this paper, we have analyzed a variety of architecture to implement Giga bps VPN system. The proposed architecture will satisfy the needs of clients who adopt Giga bps VPN system in the various environments.

• Proceedings of the IEEK Conference
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• summer
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• pp.321-324
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• 2004

A VPN is widely used in a communications environment which access is controlled to permit peer connections only within a defined community of interest. It is constructed through some form of partitioning of a common underlying communication medium, where this underlying communications medium provides services to the network on a non-exclusive basis. In this paper, we have analyzed a variety of architecture to implement Giga bps VPN system. The proposed architecture will satisfy the needs of clients who adopt Giga bps VPN system in the various environments.

• Journal of Mechanical Science and Technology
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• v.16 no.7
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• pp.959-965
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• 2002

Effective hydraulic conductivity of a statistically anisotropic heterogeneous medium is obtained for steady two-dimensional flows employing stochastic analysis. Flow equations are solved up to second order and the effective conductivity is obtained in a semi-analytic form depending only on the spatial correlation function and the anisotropy ratio of the hydraulic conductivity field, hence becoming a true intrinsic property independent of the flow field. Results are obtained using a statistically anisotropic Gaussian correlation function where the anisotropy is defined as the ratio of integral scales normal and parallel to the mean flow direction. Second order results indicate that the effective conductivity of an anisotropic medium is greater than that of an isotropic one when the anisotropy ratio is less than one and vice versa. It is also found that the effective conductivity has upper and lower bounds of the arithmetic and the harmonic mean conductivities.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2261-2266
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• 2007

In this study, the numerical analysis to estimate condensation heat and mass transfer of the condenser was carried out using the PMA (porous medium approach). In the PMA, the details of tube bundle in the condenser are replaced by the porous medium, and the flow resistance term is added in the momentum equation. In this regard, the PMA is quite helpful for the study of tube bundle in the large condenser. The pressure loss through tube bundle can be compensated by viscous and inertial momentum sink terms, which was validated numerically. Value of the pressure drop was compared to that of Butterworth correlation. Three dimensional analysis of condensation for McAllister condenser with the PMA was conducted using Fluent 6.2 and UDFs (use-defined functions). The result of condensation rate was analogous to previous results (experimental and numerical data).

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.85-93
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• 1995

In order to examine the effect of testosterone of the cell growth, using a primary rabbit kidney proximal tubule cell culture system, we observed the effect of 3 growth factors and testosterone supplementation on the growth of primary rabbit kidney proximal tubule cells in the serum-free medium. 1 nM of testosterone showed a potentiation of the effect on the growth of the proximal tubule cell in serum-free medium, but higher concentration (>10 nM) of testosterone indeed inhibited the growth. In the absence of hydrocortisone as a growth supplement in serum-free medium, testosterone caused to potentiate the growth of the cell. In the presence of hydrocortisone, testosterone also potentiated the grwoth of the proximal tubule cells. According to the Northern analysis, testosterone increased significantly the level of ${\beta}-actin$ mRNA in proximal tubular cells of rabbit kidney. Consequently we may suggest that growth stimulatory effect of testosterone on the primary rabbit kidney proximal tubule cell in serum-free and hormonally defined media ascribed to increase the synthesis of ${\beta}-actin$, which is an important protein consisting of cellular microfilament.

• Reproductive and Developmental Biology
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• v.38 no.4
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• pp.143-146
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• 2014

Antioxidants, as reactive oxygen species scavengers, are one of the beneficial additives in serum-free defined culture medium. In this study, three separate experiments were performed to determine the effects of 3-hyroxyflavone added to the culture medium on the developmental competence of follicular bovine oocytes during in vitro maturation (IVM) and/or in vitro culture (IVC). The rate of blastocyst developed from oocytes cultured in IVM medium with 3-hyroxyflavone was significantly higher than that from control oocytes (39.0% vs. 26.3%, p<0.001), respectively. However, oocytes cultured in the medium with addition of 3-hyroxyflavone only at IVC period did not show significance in the blastocyst development when compared with control. When 3-hyroxyflavone was added to both IVM and IVC media, the rate of blastocyst formation was even significantly lower (21.1%) than control (26.5%; p<0.05). The present findings suggested that antioxidative activity of 3-hydroxyflavone added to only IVM medium beneficially affected the developmental competence of follicular bovine.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.41-47
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• 2012

To adapt to a rapidly changing business environment, introduction of new management techniques and innovative activities are crucial. In the case of small and medium companies, the compensation for scarce management resources and sustainable development can be obtained from advantage of management consulting. In this study, we propose the enterprise process evaluation model for small and medium business consulting, which can deploy the process improvement activities with considering the process maturity level within an organization. The process evaluation area of proposed Small and Medium Business, Staged Maturity Model (SMB-SMM) consists of four following parts: supply management, demand management, business management, and research and development (R&D) management. For each area, we set goals and also define the practices to achieve their goals respectively. By applying the SMB-SMM model to the small and medium sized companies, the process maturity level can be defined. And then to overcome the gap between the goals and evaluation results, the customized management consulting activities can be drawn from the predefined consulting approaches from the SMB-SMM.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.362-367
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• 2003

Coriolus versicolor was grown in a defined synthetic liquid medium and citrus extracts, and the culture extracts were examined for antioxidant activity, nitrite scavenging activity, and in vitro anticancer activity against HeLa, PC-3, HepG2, and A-549 cells. Whereas the culture extracts obtained from the synthetic medium and the un-inoculated citrus extract showed 60 and 22％ of the 1,1-diphenyl-2-picrylhydrazyl radical scavenger activity, the culture extracts obtained from the citrus extracts medium exhibited antioxidant activity up to 89％. The nitrite scavenging activity of the culture extracts obtained from the citrus extracts medium and the synthetic liquid medium, and the un-inoculated citrus extract at pH 1.2 were up to 67, 55, and 34％, respectively. The culture extract obtained from the synthetic liquid medium inhibited the growth of HeLa, PC-3, HepG2, and A-549 up to 66, 23, 18, 10％ at 48 h of incubation, respectively; however, the culture extract obtained from the citrus extracts medium inhibited the growth of HeLa, PC-3, HepG2, and A-549 up to 75, 82, 55, and 82％, respectively. As a negative control, the un-inoculated citrus extract was examined in the same way and inhibited the growth of HeLa, PC-3, and HepG2 cells 20, 6, and 15％ at 48 h incubation, respectively; the inhibition of A-549 cell growth was negligible. These results clearly showed that the fermentation of C. versicolor in the citrus extracts rather than in the defined synthetic medium significantly enhanced the anticancer activity, antioxidant activity, and nitrite scavenging activity.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.500-506
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• 2009

A modified Tris-buffered medium (mTBM) has been widely used as an insemination medium for porcine in vitro fertilization (IVF). We examined whether mTBM could be used for bovine IVF. Bovine cumulus-oocyte complexes (COCs) were cultured in a serum-free medium containing 30 ng/ml EGF for 22 h. After culture, COCs were inseminated with spermatozoa for 12 h in mTBM containing 5 mM caffeine and 10 g/ml heparin. The penetration of oocytes increased significantly (p<0.05) as the sperm concentration increased from 0.1 (30%) to 1-10 $(87-100%){\times}10^6$ cells/ml. This was significantly different from values obtained at 1 (87%) and 10 $(100%){\times}10^6$ cells/ml. However, when COCs were inseminated with spermatozoa from different bulls, the proportions (62-100%) of oocytes penetrated varied according to the bull. The proportion (18%) of oocytes penetrated was significantly (p<0.05) lower in a fertilization medium without caffeine and heparin but increased with the addition of caffeine and/or heparin to the medium, and the proportion (93-96%) of oocytes penetrated increased significantly (p<0.05) when the medium was supplemented with heparin and caffeine. In this medium, sperm penetration was first observed at 3 h after insemination. Irrespective of the presence of glucose in the fertilization medium, the proportion (93-97%) of oocytes penetrated and the proportion (83-84%) of embryos at the ${\geq}2$-cell stage cultured in a chemically defined medium were not significantly different. However, the proportion of embryos developing to the blastocyst stage was significantly (p<0.05) higher in the presence (11%) of glucose in the fertilization medium than in its absence (2%). In conclusion, the present study demonstrated that bovine oocytes penetrated in vitro in mTBM can develop to the blastocyst stage and mTBM may be used for the in vitro production of bovine embryos.

• ETRI Journal
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• v.26 no.3
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• pp.241-251
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• 2004

We propose two improved scalar multiplication methods on elliptic curves over $F_{{q}^{n}}$ $q= 2^{m}$ using Frobenius expansion. The scalar multiplication of elliptic curves defined over subfield $F_q$ can be sped up by Frobenius expansion. Previous methods are restricted to the case of a small m. However, when m is small, it is hard to find curves having good cryptographic properties. Our methods are suitable for curves defined over medium-sized fields, that is, $10{\leq}m{\leq}20$. These methods are variants of the conventional multiple-base binary (MBB) method combined with the window method. One of our methods is for a polynomial basis representation with software implementation, and the other is for a normal basis representation with hardware implementation. Our software experiment shows that it is about 10% faster than the MBB method, which also uses Frobenius expansion, and about 20% faster than the Montgomery method, which is the fastest general method in polynomial basis implementation.