• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.6
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• pp.50-57
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• 1997

TiO$_{2}$ tin films have been grown by MOCVD and their cahracteristics of crystallization and microstructures ahve been invetigated. Envelope mehtods are applied to the analysis of the transmission spectra to obtain the optical constants such as refractive indices and extinction coefficients for the TiO$_{2}$ thin films. The envelope methods are proved to be accurate by simulatin gthe transmission spectra. TiO$_{2}$ thin films start to crystallize at 350.deg.C and then crystallize fully into anatase phase at 400.deg.C or higher temperatures. Activation energies are obtained by plotting the deposition rate with varying the substrate temperature. It is 17.8 kcal/mol for the reaction limited regions. The refractive index and the extinction coefficient of the TiO$_{2}$ thin film at .gamma.=632.8 nm increases from 2.19 to 2.32 and decreases from 0.021 to 0.007, respectively, as the substrate temperature increases from 400 to 600.deg. C.

• Convergence Security Journal
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• v.8 no.4
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• pp.121-126
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• 2008

It is of great practical interest to decide when to stop testing a software system in development phase and transfer it to the user. This decision problem called an optimal release policies. In this paper discussed to specify an optimal release policies. In this paper, propose an optimal release policies of the life distribution applied Erlang distribution of special pattern of Gamma distribution. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. From Sensitivity Analysis, make out estimating software optimal release time.

• Korean Journal of Materials Research
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• v.15 no.12
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• pp.760-764
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• 2005

The influences of the oxidant($O_2\;and\;O_3$) on the FeOOH formation were studied with fixed $FeSO_4{\cdot}7H_2O$ concentration (0.5M) and NaOH equivalent ratio(0.5). The characteristics of the synthesized powders were evaluateed by XRD, and equantitative phase analysis. $\alpha-FeOOH$ (Geothite) and/or $\gamma-FeOOH$ was promoted when $O_3$ was used as a oxidant which is stronger oxidizing agent than $O_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.2
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• pp.128-132
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• 2010

Photonic crystal is dielectric materials or a set of different dielectric materials with periodic structure. Line defect is obtained by leaving out a row of rods along the $\Gamma$-X direction. We showed the change of group velocity in waveguide mode and found resultant small group velocity. Characteristics of the small group velocity were described by electric field distribution. Investigating the phase shift, it is confirmed if small group velocity is positive or negative.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.472-473
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• 2006

Maghemite and hematite nanospheres were synthesized by using the Sol-gel technique. The structural properties of these nanosphere powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and pore size distribution. Hematite phase shows crystalline structures. The mean particle size that resulted from BET and XRD analyses were 4.9 nm and 2 nm. It can be seen from transmission electron microscopy that the size of the particles are very small which is in good agreement with the FESEM and the X-ray diffraction. The BET and pore size method were employed for specific surface area determination.

• Journal of Surface Science and Engineering
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• v.39 no.4
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• pp.147-152
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• 2006

Failure mechanisms of electron beam physical vapor deposited thermal barrier coatings(EB-PVD TBCs) that occur during thermal cyclic oxidation were investigated. The investigations include microstructural degradation of NiCrAIY bond coat, thermally grown oxides(TGOs) along the ceramic top coat-substrate interface and fracture path within TBCs. The microstructural degradation of the bond coat during cyclic oxidation created Al depleted zones, resulting in reduction of NiAl and ${\gamma}$-Ni solid solution phase. It was observed that the fracture took placed primarily within the TGOs or at the interfaces between TGOs and bond coat.

• Journal of the Mineralogical Society of Korea
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• v.3 no.2
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• pp.65-71
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• 1990

Compositions and thermal changes of pyrrhotites from Ohtani and Uljin mines were examined by Arnold's method and DTA analysis. The results are as follow: 1) The compositions of hexagonal type pyrrhotite are in some range from 47.23-47.42 atom.% Fe in the Ohtani mine, and 47.40-47.64 atom.% Fe in the Uljin mine. 2) The compositions of hexagonal pyrrhotite with exsoluted lamellae of monoclinic pyrrhotite are in 47.35-47.50 atom.% Fe in the Ohtani mine, and 47.15-47.40 atom.% Fe in the Uljin mine. This fact does not agree with phase diagrams of Fe-S system shown by Nakazawa and Morimoto(1970) and Sugaki and Shima(1977). 3) DTA data show two endothermic peak corresponding to ${\gamma}$ and $\beta$ transformation. Sturctural conversions from order(intermediate) to disorder(high) forms occur at about $300^{\circ}C$ for hexagonal type and further lower temperature with increasing Fe-content.

• Journal of Surface Science and Engineering
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• v.14 no.1
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• pp.5-9
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• 1981

The effects of silicon content on the corrosion rates of Cu-7wt% Al alloys have been investigated by the use of electrochemical methods. The corrosion current densities of the alloys are decreased with the addition of Si up to 2wt%, and the slightly increased at 2.5%Si. This increased corrosion rates are attributed to the precipitation of more anodic gamma-2 phase. The X-ray diffraction tests reveal the dealuminumification of these alloys and mixtures of CuCl and Al2O3 formed on the surface of the specimens, which are considered to passivate the alloys at noble potentials.

• Molecules and Cells
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• v.42 no.11
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• pp.794-803
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• 2019

Ultraviolet light (UV)-induced cellular response has been studied by numerous investigators for many years. Long noncoding RNAs (lncRNAs) are emerging as new regulators of diverse cellular process; however, little is known about the role of lncRNAs in the cellular response to UV treatment. Here, we demonstrate that levels of lncRNA-HOTTIP significantly increases after UV stimulation and regulates the UV-mediated cellular response to UV through the coordinate activation of its neighboring gene Hoxa13 in GC-1 cells (spermatogonia germ cell line). UV-induced, G2/M-phase arrest and early apoptosis can be regulated by lncRNA-HOTTIP and Hoxa13. Furthermore, lncRNA-HOTTIP can up-regulate ${\gamma}-H_2AX$ and p53 expression via Hoxa13 in UV-irradiated GC-1 cells. In addition, p53 has the ability to regulate the expression of both lncRNA-HOTTIP and Hoxa13 in vitro and in vivo. Our results provide new data regarding the role lncRNAs play in the UV response in spermatogenic cells.

• YAKHAK HOEJI
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• v.16 no.4
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• pp.180-185
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• 1972

A new spectrophotometric method was established for the determination of undecylenic acid. The method is based on the solvent extraction into nitrobenzene of the ion pair formed between tris(1,10-phenanthroline)Fe(II) chelate and the anion of undecylenic acid. The maximum absorbance of the extract in the organic phase was at 518nm. A maximum extraction was obtained at pH 9-11, when excess of at least 50-fold(molar) of the phenanthroline-Fe(II) chelate to undecylenic acid was present. The color intensity of the extracted species remained constant at room temperature for the several hours after separation of the organic layer. A linear relationship was obtained over the tested range of 5-20${\gamma}$/ml of undecylenic acid. The effect of several other fungicids on this method was investigated. The method was applied to the determination of undecylenic acid in preparations and the results were in good agreement with those added amounts.