• Bulletin of the Korean Mathematical Society
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• v.51 no.1
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• pp.77-82
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• 2014

We prove that if ${\mid}a_1{\mid}$ is large and ${\mid}a_0{\mid}$ is small enough, then every approximate zero of power series equation ${\sum}^{\infty}_{n=0}a_nx^n$=0 can be approximated by a true zero within a good error bound. Further, we obtain Hyers-Ulam stability of zeros of the polynomial equation of degree n, $a_nz^n$ + $a_{n-1}z^{n-1}$ + ${\cdots}$ + $a_1z$ + $a_0$ = 0 for a given integer n > 1.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.17 no.4
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• pp.267-278
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• 2013

We consider zero range processes with density dependent jump rates g given by $g=g(n,k)=g_1(n)g_2(k/n)$ with $g_1(x)=x^{-\alpha}$ and $$g_2(x)=\{^{x^{-\alpha}\;if\;a&lt;x}_{Mx^{-\alpha}\;if\;x{\leq}a}$$. (0.1) In this case, with 1/2 < a < 1 and ${\alpha}$ > 0, we show that non-complete condensation occurs with maximum cluster size an. More precisely, for any ${\epsilon}$ > 0, there exists $M^*$ > 0 such that, for any 0 < M ${\leq}M^*$, the maximum cluster size is between (a - ${\epsilon}$)n and (a + ${\epsilon}$)n for large n. This provides a simple example of non-complete condensation under perturbation of rates which are deep in the range of perfect condensation (e.g. ${\alpha}$ >> 1) and supports the instability of the condensation transition.

• Kyungpook Mathematical Journal
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• v.50 no.4
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• pp.465-472
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• 2010

In this paper, we consider two extreme sets of zero-term rank sum of fuzzy matrix pairs: $$\cal{z}_1(\cal{F})=\{(X,Y){\in}\cal{M}_{m,n}(\cal{F})^2{\mid}z(X+Y)=min\{z(X),z(Y)\}\};$$ $$\cal{z}_2(\cal{F})=\{(X,Y){\in}\cal{M}_{m,n}(\cal{F})^2{\mid}z(X+Y)=0\}$$. We characterize the linear operators that preserve these two extreme sets of zero-term rank sum of fuzzy matrix pairs.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.39-45
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• 2010

Zero Emission Building is abuilding which emits virtually '0(zero)' carbon dioxide. Although simple in concept, ZEB requires totally different approach from conventional building in terms of design, engineering, construction and operation. There are few research on ZEB design process as ZEB design requires understanding and knowledge regarding energy and technology. The study aims to propose a design process of Zero Emission Building for architects. The study examined the concept of Zero Emission Building through intensive literature search. The examples of Zero Emission Buildings were investigated, and strategies and technologies applied to the buildings were analyzed. Various conventional design processes were identified and analyzed to examine the applicability to ZEB design, Finally, a new design process which effectively accommodate the requirement of Zero Emission Building was proposed.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.225-232
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• 2014

Optical parametric amplification has been analyzed for the Cerenkov-idler configuration in planar waveguides. The coupled-mode theory is employed for the analysis. The coupled-mode equations are derived and the approximate analytic solution is obtained for no pump depletion. From the analytic solution, it is shown that the signal power gain can be enhanced as the Cerenkov radiation angle of the idler approaches to zero. The numerical example is also shown for the effect of the Cerenkov radiation angle approaching zero.

• Bulletin of the Korean Mathematical Society
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• v.52 no.6
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• pp.1819-1826
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• 2015

Following an idea of Ornstein and Sucheston, Foguel proved the so-called uniform "zero-two" law: let T : $L^1$(X, $\mathcal{F}$, ${\mu}$) ${\rightarrow}$ $L^1$(X, $\mathcal{F}$, ${\mu}$) be a positive contraction. If for some $m{\in}{\mathbb{N}}{\cup}\{0\}$ one has ${\parallel}T^{m+1}-T^m{\parallel}$ < 2, then $\lim_{n{\rightarrow}{\infty}}{\parallel}T^{m+1}-T^m{\parallel}=0$. There are many papers devoted to generalizations of this law. In the present paper we provide a multi-parametric generalization of the uniform zero-two law for $L^1$-contractions.

• Resources Recycling
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• v.8 no.3
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• pp.43-48
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• 1999

The pupose of h s study was to develop a process for removal of unburnzd carbon li-om fly ash by froth flotation. "Carbon zero (C.Z)" develqcd by KIGAM, gave the best results, praduci112 cleaned fly ash containing abom 0.1% FC with 72% yieldBased on the results of batch flotation tests, the pilot-scale tests wcre conducted. The result showed that cleaned fly ash with 0.1% FC could be recovered by about 73% yield.t 73% yield.

• Economic and Environmental Geology
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• v.34 no.3
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• pp.307-313
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• 2001

Reactive medium including zero-valent metals such as zero-valent iron ($Fe^0$) degrades chlorinated solvents as a contaminant plume flows through the treatment medium. Although the Feo based reactive barrier has been demonstnlted to be a cost effective for trichloroethenc (TCE)-contaminaled plume remediation, current approach is limited by low process eftlciency and uncertain, effective life of the medium. The objective of this study is to develop an enhanced treatment method of TeE-contaminated groundwater using Feo and direct current. The bench-scale test using flow-through $Fe^0$ reactor column confirmed that the application of direct current with $Fe^0$ is highly effective in enhancing the rate of TeE dechlorination. The dechlorination mechanism appears to be reductive, with the electrons supplied by the iron oxidation and external power supply serving as the additional source of electrons.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.723-732
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• 2022

Cracking ammonia inside solid oxide fuel cell (SOFC) stack is a compact and simple way. To prevent sharp temperature fluctuation and increase cell efficiency, the decomposition reaction should be spread on whole cell area. This leading to a question that, how does anode thickness affect the conversion rate of ammonia and the cell voltage? Since the 0D model of SOFC is useful for system level simulation, how accurate is it to use equilibrium solver for internal ammonia cracking reaction? The 1D model of ammonia fed SOFC was used to simulate the diffusion and reaction of ammonia inside the anode electrode, then the partial pressure of hydrogen and steam at triple phase boundary was used for cell voltage calculation. The result shows that, the ammonia conversion rate increases and reaches saturated value as anode thickness increase, and the saturated thickness is bigger for lower operating temperature. The similar cell voltage between 1D and 0D models can be reached with NH₃ conversion rate above 90%. The 0D model and 1D model of SOFC showed similar conversion rate at temperature over 750℃.

• Journal of the Korean Mathematical Society
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• v.51 no.6
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• pp.1291-1304
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• 2014

In 2005 Kadiri proved that the Riemann zeta function ${\zeta}(s)$ does not vanish in the region $$Re(s){\geq}1-\frac{1}{R_0\;{\log}\;{\mid}Im(s){\mid}},\;{\mid}Im(s){\mid}{\geq}2$$ with $R_0=5.69693$. In this paper we will show that $R_0$ can be taken $R_0=5.68371$ using Kadiri's method together with Platt's numerical verification of Riemann Hypothesis.