• Korean Journal of Materials Research
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• v.9 no.12
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• pp.1234-1239
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• 1999

Electromagnetic wave asorbing properties of the $Ni_{0.5}-Zn_{0.4}-X_{0.1}{\cdot}Fe_2O_4$, where X was replaced by substitution elements Cu, Mg, Mn, have been studied. The structure, shape, size and magnetic properties of the $Ni_{0.5}-Zn_{0.4}-X_{0.1}{\cdot}Fe_2O_4$ were analyzed by XRD, SEM, VSM. The relative complex permittivity, permeability, and electromagnetic wave absorbing properties were measured by Network Analyzer. The structure, shape, size and magnetization value of the $Ni_{0.5}-Zn_{0.4}-X_{0.1}{\cdot}Fe_2O_4$ were found to be similar in spite of substitution elements. The coercive force and hysteresis-loss showed maximum value when Mg was substituted for X. The dielectric loss(${\varepsilon}_r"/{\varepsilon}_r'$) was found to be maximum value when Mn was substituted for X. Also the magnetic loss(${\mu}_r"/{\mu}_r'$} was found to be maximum with Cu substitution. The electromagnetica wave absorbing property of the $Ni_{0.5}-Zn_{0.4}-X_{0.1}{\cdot}Fe_2O_4$-Rubber composite with 4mm thickness was excellent as over - 40dB at 9GHz, and the $Ni_{0.5}-Zn_{0.4}-X_{0.1}{\cdot}Fe_2O_4$-Rubber composite with 8mm thickness was over-40dB at 2GHz. Those composites also showed superior microwave absorbing properties.

• Transactions on Electrical and Electronic Materials
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• v.16 no.2
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• pp.90-94
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• 2015

In this study, the characterizations of oxide contact hole etching are investigated with C₄F₈/O₂/Ar and CH₂F₂/C₄F₈/O₂/ Ar plasma. As the percent composition of C₄F₈ in a C₄F₈/O₂/Ar mixture increases, the amount of polymer deposited on the etched surface also increases because the C_xF_y polymer layer retards the reaction of oxygen atoms with PR. Adding CH₂F₂ into the C₄F₈/O₂/Ar plasma increases the etch rate of the oxide and the selectivity of oxide to PR. The profile of contact holes was close to 90°, and no visible residue was seen in the SEM image at a C₄F₈/(C₄F₈+O₂) ratio of 58%. The changes of chemical composition in the chamber were analyzed using optical emission spectroscopy, and the chemical reaction on the etched surface was investigated using X-ray photoelectron spectroscopy.

• Korean Journal of Crystallography
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• v.15 no.2
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• pp.99-103
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• 2004

The structure of $C_{16}H_{19}O_2N_3CuCl_2\;{\cdot}\;H_2O$ has been determined by X-ray diffraction methods. The crystal system is triclinic, space group Pl, unit cell constants. $a=7.6202(9)\; \AA,\; b=8.5943(7) \AA,\; c= 8.6272(6) \AA,\; \alpha= 67.518(6)^{\circ}.\; \beta= 68.043(8)^{\circ},\; \gamma=74.370(8)^{\circ},\; V=478.89(8)\; \AA^3,\; T=295K,\; Z=1,\; D_c=1.504Mgm^{-3}$The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with graphite monochromated $MoK\alpha$ radiation $(\alpha=0.7107\;\AA)$. The molecular structure was solved by direct method.』 and refined by full-matrix least squares to a final $R=2.47\%$ for 1659 unique observed $F_0>4\sigma(F_0)$ reflections and 234 parameters.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.955-960
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• 2008

We investigated and estimated at the characteristics of decomposition and mineralization of benomyl using a design of experiment(DOE) based on the general factorial design in an E-beam process, and also the main factors(variables) with benomyl concentration(X$_1$) and E-beam irradiation(X$_2$) which consisted of 5 levels in each factor was set up to estimate the prediction model and the optimization conditions. At frist, the benomyl in all treatment combinations except 17 and 18 trials was almost degraded and the difference in the decomposition of benomyl in the 3 blocks was not significant(p > 0.05, one-way ANOVA). However, the % of benomyl mineralization was 46%(block 1), 36.7%(block 2) and 22%(block 3) and showed the significant difference of the % that between each block(p < 0.05). The linear regression equations of benomyl mineralization in each block were also estimated as followed; block 1(Y$_1$ = 0.024X$_1$ + 34.1(R$^2$ = 0.929)), block 2(Y$_2$ = 0.026X$_2$ + 23.1(R$^2$ = 0.976)) and block 3(Y$_3$ = 0.034X$_3$ + 6.2(R$^2$ = 0.98)). The normality of benomyl mineralization obtained from Anderson-Darling test in all treatment conditions was satisfied(p > 0.05). The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were Y = 39.96 - 9.36X$_1$ + 0.03X$_2$ - 10.67X$_1{^2}$ - 0.001X$_2{^2}$ + 0.011X$_1$X$_2$(R$^2$ = 96.3%, Adjusted R$^2$ = 94.8%) and 57.3% at 0.55 mg/L and 950 Gy, respectively. A Microtox test using V. fischeri showed that the toxicity, expressed as the inhibition(%), was reduced almost completely after an E-beam irradiation, whereas the inhibition(%) for 0.5 mg/L, 1 mg/L and 1.5 mg/L was 10.25%, 20.14% and 26.2% in the initial reactions in the absence of an E-beam illumination.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.6 s.360
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• pp.1-7
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• 2007

This paper proposes CMOS semi-digital data recovery with 2X converse oversampling to reduce power consumption and chid area of high definition multimedia interface (HDMI) receivers. Proposed recovery can reduce its power and the effective area by using nt converse oversampling algorithm and semi-digital architecture. Proposed circuit is fabricated using 0.18um CMOS process and measured results demonstrated the power consumption of 14.4mW, the effective area of $0.152mm^2$ and the jitter tolerance of 0.7UIpp with 1.8V supply voltage.)

• Journal of Power System Engineering
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• v.8 no.3
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• pp.18-22
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• 2004

Boiler is one of the most important utilities providing steam to turbine in order to supply mechanical energy in thermal power plant. It is composed of thousands of tubes for high efficient heat transfer. The material for boiler tubes is used in such high temperature and pressure condition as $540^{\circ}C$, 22MPa. The boiler tube material is required to resist creep damage, fatigue cracking, and corrosion damages. 2.25%Cr-1Mo steel is used for conventional boiler tubes, and austenitenite stainless steel is used for higher temperature boiler tubes. But the temperature and pressure of steam in power plant became higher for high plant efficiency. So, the property of boiler tube material must be upgaded to fit the plant property. Several boiler tube material was developed to fit such conditions. X20CrMoV12.1 steel is also developed in 1980's and used for superheater and reheater tubes in supercritical boilers. The material has martensite microstructures which is difficult to evaluate the degradation. In this thesis, degrade the X20CrMoV12.1 steel at high temperatures in electric furnace, and evaluate hardness with Vickers hardness tester and strengths with Indentation tester.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.609-612
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• 1998

Pyroelectric properties of rhombohedral $Pb(ZrxTi_1-x)O_3ceramics$ with various Zr/Ti ratios of 84/16, 87/13, 90/10, and 93/7 are investigated using dynamic method. The response characteristics of PZT samples are examined by considering frequency dispersion. Since the reorientation of the grain does not the influence on the increase of frequency at low frequency (2~200Hz), the maximum pyroelectric response can be obtained with the change of spontaneous polarization. However, the pyroelectric response of PZT samples could be reduced as the spontaneous polarization decreases due to the restrain of the reorientation of the grain with the increasing of requency at high frequency (200~2000Hz). We have obtained the good pyroelectric response in the PZT sample having 84/16 Zr/Ti ratio, then the pyroelectric coefficient (${\gamma}$) and the figure of merit (FV) were $17.3nC/\textrm{cm}^2K$ and 2.28$\times$10-11Ccm/J, respectively. The noise equivalent power (NEP), the detectivity (D*) were 1.21$\times$10-7W/Hz$\frac{1}{2}$ and 8.26$\times$106cmHz$\frac{1}{2}$/W, respectively.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.77-84
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• 2015

This paper presents the design of a low-power, low area 256-radix 16-bit crossbar switch employing a 2D Hyper-X network topology. The Hyper-X crossbar switch realizes the high radix of 256 by hierarchically combining a set of 4-radix sub-switches and applies three modifications to the basic Hyper-X topology in order to mitigate the adverse scaling of power consumption and propagation delay with the increasing radix. For instance, by restricting the directions in which signals can be routed, by restricting the ports to which signals can be connected, and by replacing the column-wise routes with diagonal routes, the fanout of each circuit node can be substantially reduced from 256 to 4~8. The proposed 256-radix, 16-bit crossbar switch is designed in a 65 nm CMOS and occupies the total area of $0.93{\times}1.25mm^2$. The simulated worst-case delay and power dissipation are 641 ps and 13.01 W when operating at a 1.2 V supply and 1 GHz frequency. In comparison with the state-of-the-art designs, the proposed crossbar switch design achieves the best energy-delay efficiency of $2.203cycle/ns{\cdot}fJ{\cdot}{\lambda}2$.

• BMB Reports
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• v.35 no.5
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• pp.452-458
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• 2002

Exposure to ultraviolet light (UV) induces apoptosis in mammalian cells, The caspase group of proteases is required for the appotosis. This pathway is initiated by a release of cytochrome c from the mitochondria into the cytosol. Several Bcl-2 family proteins can regulate the release of cytochrome c by stabilizing the mitochondrial membrane. Here we show that expression of the endogenous bcl-xL was strongly downregulated in NIH3T3 cells within 2 h after UV-C irradiation, and that of bax was upregulated from 8 h after irradiation. Apoptosis was induced in more than 50% of the NIH3T3 cells 48 h after irradiation. Constitutive overexpression of bcl-xL in NIH3T3 cells protected the UV-induced apoptosis by preventing the loss of mitochondrial membrane potential and the activation of caspase 9. There results suggest that downregulation of Bcl-xL is relevant to UV-induced apoptosis of tibroblasts.

• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.536-543
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• 2005

3D online game, with its striking realistic value, is leading the entire Korean game market which has various game genres. Technology sharing is very hard within the Korean game industry. That is because 1)there are few professionals, 2)most of the companies are small-scaled, and 3)there are security reasons. Therefore, it should be significant if we have software design techniques which make it possible to reuse the existing code when developing a network game so that we could save a lot of efforts. In this paper, the author analyzes the demand through the case in the client's design of the network game based on DirectX and proposes the effective software design methods for reusable code based on the creative patterns application in the GoF in the class design.