• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.499-507
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• 2010

In this note, we study the local spectral properties of semi-shifts. If $T\;{\in}\;L(X)$ is a semi-shift on a complex Banach space X, then T is admissible. We also prove that if $T\;{\in}\;L(X)$ is subadmissible, then $X_T(F)\;=\;E_T(F)$ for all closed $F\;{\subseteq}\;\mathbb{C}$. In particular, every subscalar operator on a Banach space is admissible.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.844-847
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• 1989

This work describes an on-line method and procedure for calculating the fluid properties in real time while system is in operation. The method utilizes function blocks of distributed control systems. Thermodynamic relations of fluid from tables along with a fluid property formula are imbedded into the proposed signal processing block. Once the pressure and temperature measurements are entered the system provides other properties.

• Journal of the Chungcheong Mathematical Society
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• v.22 no.1
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• pp.1-5
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• 2009

Let {$X_n,\;n{\geq}1}$ be a sequence of independent identically distributed(i.i.d.) sequence of positive random variables with common absolutely continuous distribution function(cdf) F(x) and probability density function(pdf) f(x) and $E(X^2)<{\infty}$. The random variables $\frac{X_i{\cdot}X_j}{(\Sigma^n_{k=1}X_k)^{2}}$ and $\Sigma^n_{k=1}X_k$ are independent for $1{\leq}i if and only if {$X_n,\;n{\geq}1}$ have gamma distribution.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.465-468
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• 2003

E-mail, one of the oldest services in internet becomes very important and essential way to communicate with development of internet. Due to E-mail has a property which is not complete for security, sometimes it is used for purpose of commercial or bad things, therefore it becomes the latest problem to keep off a Spam-mail and commercial advertising E-mail, many ways to keep off were perposed for it. In this paper, I explained how to sort and keep off these Spam-mail and commercial advertising E-mail with three way, prevention by server level, prevention by construction of network level, prevention by client level. we designed a prevention system for Spam-mail and implemented it by Visual Basic.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.291-297
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• 1998

Cop protein has been overexpressed in Escherichia coli using a T7 RNA polymerase system. Purification to apparent homogeneity was achieved by the sequential chromatography on ion exchange, affinity chromatography, and reverse phase high performance liquid chromatography system. The molecular weight of the purified Cop was estimated as 6.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). But the molecular mass of the native state Cop was shown to be 19 kDa by an analytical high performance size exclusion chromatography, suggesting a trimer-like structure in 50 mM Tris-HCI buffer (pH 7.5) containing 100 mM NaCl. Cop protein Was calculated to contain $39.1% {\alpha}-helix, 16.8% {\beta}-sheet$, 17.4% turn, and 26.8% random structure. The DNA binding property of Cop protein expressed in E. coli Was preserved during the expression and purification process. The isoelectric point of Cop was determined to be 9.0. The results of amino acid composition analysis and N-terminal amino acid sequencing of Cop showed that it has the same amino acid composition and N-terminal amino acid sequence as those deduced from its DNA sequence analysis, except for the partial removal of N-terminal methionine residue by methionyl-aminopeptidase in E. coli.

• Journal of the Korean Geophysical Society
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• v.3 no.2
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• pp.127-138
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• 2000

This study was conducted to examine the differences between dynamic and static elastic constants by use of some laboratory tests of cement mortar specimens which have different water/cement mixing ratios. Specific gravity measurement, ultrasonic velocity estimating and uniaxial compression test were adopted to acquire the dynamic and static elastic constants. Digital data acquisition and processing enhanced the accuracy of estimating the velocities of specimens drastically, Also, the method using the gradient of propagation delay time in according to increment of specimen length more enhanced the accuracy than the method using the only one specimen length over total propagation time. The correlation between density and the P and S wave velocity of specimens shows reliable positive relation and the correlation between density and the strength of uniaxial compression has the similar relationship. The dynamic Young's modulus $(E_D)$ is alway greater than the static Young's modulus $(E_S)$ and there is increasing tendency of the ratio $(E_D/E_S)$ according to the increase of density or strength of the specimens. On the other hand, there is no typical relationship between dynamic Poisson's ratio $({\nu}_D)$ and static Poisson's ratio $({\nu}_S)$ and just the ratio of ${\nu}_D/{\nu}_S$ ranges front 69 to 122 %.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.641-649
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• 2011

The aim of this study is to understand the characteristics of exhausting particulate matters (PM) and to control emitted PM from meat cooking restaurants. We found that $PM_{2.5}$, $PM_{5.0}$ occupy 69.2% and 98.6% of total PM from pork cooking, respectively. Therefore, we can see that it is not easy to remove PM generated from a pork cooking process. The collection efficiencies of various control devices, which are a condensing scrubber, a cyclone, an impactor, an oil filter and an electrostatic precipitator (ESP), were measured and compared. ESP had the highest collection efficiency (88.6%) and condensing scrubber had the lowest one (68.0%). However, the system recovering property should be considered to choose a control device because PM from meat cooking process are extremely stickiness. Therefore, we can recommend that ESP following an impactor or a cyclone is the best combination to remove PM generated from meat cooking restaurants.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.55-61
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• 2014

The autoignition temperature (AIT) of a material is the lowest temperature at which the substance will spontaneously ignite in the absence of an external ignition source such as a spark or flame. The AIT may be used as combustion property to specify operating, storage, and materials handling procedures for processs safety. This study measured the AITs of n-Propanol+n-Decane system from ignition delay time(time lag) by using ASTM E659 apparatus. The AITs of n-Propanol and n-Decane which constituted binary system were $435^{\circ}C$ and $212^{\circ}C$, respectively. The experimental AITs of n-Propanol+n-Decane system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D(average absolute deviation).

• Bulletin of the Korean Mathematical Society
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• v.50 no.3
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• pp.935-949
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• 2013

In this paper, we study surfaces in $\mathb{E}^3$ whose Gauss map G satisfies the equation ${\Box}G=f(G+C)$ for a smooth function $f$ and a constant vector C, where ${\Box}$ stands for the Cheng-Yau operator. We focus on surfaces with constant Gaussian curvature, constant mean curvature and constant principal curvature with such a property. We obtain some classification and characterization theorems for these kinds of surfaces. Finally, we give a characterization of surfaces whose Gauss map G satisfies the equation ${\Box}G={\lambda}(G+C)$ for a constant ${\lambda}$ and a constant vector C.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.313-319
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• 2018

This study introduces a new investigation report on the microstructural and electrical property changes of $ZnO-Zn_2BiVO_6-Mn_3O_4$ (ZZMn), where 0.33 mol% of $Mn_3O_4$ and 0.5 mol% of $Zn_2BiVO_6$ were added to ZnO (99.17 mol%) as liquid phase sintering aids. $Zn_2BiVO_6$ contributes to the decrease of sintering temperatures by up to $800^{\circ}C$, and segregates its particles at the grain boundary, while $Mn_3O_4$ enhances ${\alpha}$, the nonlinear coefficient, of varistor properties up to ${\alpha}=62$. In comparison, when the sintering temperature is increased from $800^{\circ}C$ to $1,000^{\circ}C$, the resistivity of ZnO grains decreases from $0.34{\Omega}cm$ to $0.16{\Omega}cm$, and the varistor property degrades. Oxygen vacancy ($V_o^{\bullet}$) (P1, 0.33~0.36 eV) is formed as a dominant defect. Two different kinds of grain boundary activation energies of P2 (0.51~0.70 eV) and P3 (0.70~0.93 eV) are formed according to different sintering temperatures, which are tentatively attributed to be $ZnO/Zn_2BiVO_6$-rich interface and ZnO/ZnO interface, respectively. Accordingly, this study introduces a progressive method of manufacturing ZnO chip varistors by way of sintering ZZMn-based varistor under $900^{\circ}C$. However, to procure a higher reliability, an in-depth study on the multi-component varistors with double-layer grain boundaries should be executed.