• Journal of the Korean earth science society
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• v.28 no.6
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• pp.720-732
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• 2007

For the Seoul metropolitan area and the eastern Kyeongsang Basin, we simultaneously calculated $Q_P^{-1}$ and $Q_S^{-1}$ by applying the extended coda-normalization method for 98 seismograms of local Earthquakes. As frequency increases from 1.5 Hz to 24 Hz, the result decreased from $(4.0{\pm}9.2){\times}10^{-3}$ to $(4.1{\pm}4.2){\times}10^{-4}$ for $Q_P^{-1}$ and $(5.5{\pm}5.6){\times}10^{-3}$ to $(3.4{\pm}1.3){\times}10^{-4}$ for $Q_S^{-1}$ in Seoul Metropolitan Area. The result of eastern Kyeongsang basin also decreased from $(5.4{\pm}8.8){\times}10^{-3}$ to $(3.7{\pm}3.4){\times}10^{-4}$ for $Q_P^{-1}$ and $(5.7{\pm}4.2){\times}10^{-3}$ to $(3.5{\pm}1.6){\times}10^{-4}$ for $Q_S^{-1}$. If we fit a frequency-dependent power law to the data, the best fits of $Q_P^{-1}$ and $Q_S^{-1}$ are $0.005f^{-0.89}$ and $0.004f^{-0.88}$ in Seoul metropolitan Area, respectively. The value of $Q_P^{-1}$ and $Q_S^{-1}$ in the eastern Kyeongsang basin are $0.007f^{-1.02}$ and $0.006f^{-0.99}$, respectively. The $Q_S^{-1}$ value of the eastern Kyeongsang basin is almost similar to Seoul metropolitan area. But the $Q_P^{-1}$ value of the eastern Kyeongsang basin is a little higher than that of Seoul metropolitan area. This may be that the crustal characteristics of the eastern Kyeongsang basin is seismologically more heterogeneous. However, these $Q_P^{-1}$ values in Korea belong to the range of seismically stable regions all over the world.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.475-485
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• 2006

The physical properties of the central and southwestern crust of South Korea were estimated by comparing values of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ in the Kimcheon and Mokpo areas. In order to get ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ values, seismic data were collected from two stations of the KIGAM network (KMC and MUN) and four stations of the KMA network (CPN, KUC, MOP, and WAN). An extended coda-normalization method was applied to these data. Estimates of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ show variations depending on frequency. As frequencies vary from 3 Hz to 24 Hz, the estimates decrease from $(1.4{\pm}3.9){\times}10^{-3}\;to\;(2.3{\pm}3.5){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(1.8{\pm}1.3){\times}10^{-3}\;to\;(1.9{\pm}1.5){\times}10^{-4}\;for\;{Q_S}^{-1}$ in central South Korea, and $(5.9{\pm}4.8){\times}10^{-3}\;to\;(2.2{\pm}3.8){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(0.5{\pm}2.8){\times}10^{-3}\;to\;(1.8{\pm}1.6){\times}10^{-4}\;for\;{Q_S}^{-1}$ in southwestern South Korea. According that a frequency-dependent power law is applied to the data, the best fits of ${Q_P}^{-1}\;and\;{Q_S}^{-1}\;are\;0.003f^{-0.49}\;and\;0.005f^{-1.03}$ in central South Korea, and $0.026f^{-1.47}$ and $0.001f^{-0.49}$ in southwestern South Korea, respectively. These values almost correspond to those of seismically stable regions although ${Q_P}^{-1}$ values of southwestern South Korea are a little high due to lack of data used.

• Journal of the Korean Mathematical Society
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• v.39 no.2
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• pp.277-287
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• 2002

Let B be the open unit ball with center 0 in the complex space $C^n$. For each q>0, B$_{q}$ consists of holomorphic functions f : B longrightarrow C which satisfy sup z $\in$ B $(1-\parallel z \parallel^2)^q\parallel\nabla f(z)\parallel < \infty$ In this paper, we will show that functions in weighted Bloch spaces $B_{q}$ (0 < q < 1) satifies the following Lipschitz type result for Bergman metric $\beta$: ｜f(z)-f($\omega$)｜< $C\beta$(z, $\omega$) for some constant C.

• Journal of the Korean earth science society
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• v.22 no.2
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• pp.112-119
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• 2001

The Yangsan fault in the southeastern Korea has been receiving increasing attention in its seismic activity. In this fault region, by using the extended coda-normalization method for 707 seismograms of local earthquakes, were obtained 0.009f$^{-1.05}$ and 0.004f$^{-0.70}$ for fitting values of Q$_p^{-1}$ and Q$_s^{-1}$, respectively. These results indicate that Q$_p^{-1}$ and Q$_s^{-1}$ in the southeastern Korea is the lowest level in the world although the exponent values agree well with those in the other areas. The low Q-1 is not related to the movement of the Yangsan fault but to the tectonically inactive status like a shield area.

• Communications of the Korean Mathematical Society
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• v.27 no.3
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• pp.557-564
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• 2012

This study concerns the existence of positive solution for the following nonlinear system $$\{-div(|x|^{-ap}|{\nabla}u|^{p-2}{\nabla}u)=|x|^{-(a+1)p+c_1}({\alpha}_1f(v)+{\beta}_1h(u)),x{\in}{\Omega},\\-div(|x|^{-bq}|{\nabla}v|q^{-2}{\nabla}v)=|x|^{-(b+1)q+c_2}({\alpha}_2g(u)+{\beta}_2k(v)),x{\in}{\Omega},\\u=v=0,x{\in}{\partial}{\Omega}$$, where ${\Omega}$ is a bounded smooth domain of $\mathbb{R}^N$ with $0{\in}{\Omega}$, 1 < $p,q$ < N, $0{{\leq}}a<\frac{N-p}{p}$, $0{{\leq}}b<\frac{N-q}{q}$ and $c_1$, $c_2$, ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, ${\beta}_2$ are positive parameters. Here $f,g,h,k$ : $[0,{\infty}){\rightarrow}[0,{\infty})$ are nondecresing continuous functions and $$\lim_{s{\rightarrow}{\infty}}\frac{f(Ag(s)^{\frac{1}{q-1}})}{s^{p-1}}=0$$ for every A > 0. We discuss the existence of positive solution when $f,g,h$ and $k$ satisfy certain additional conditions. We use the method of sub-super solutions to establish our results.

• Journal of the Korean Mathematical Society
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• v.54 no.1
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• pp.267-280
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• 2017

In this paper, we study analytic and geometric properties of the solution q(z) to the differential equation q(z) + zq'(z)/q(z) = h(z) with the initial condition q(0) = 1 for a given analytic function h(z) on the unit disk |z| < 1 in the complex plane with h(0) = 1. In particular, we investigate the possible largest constant c > 0 such that the condition |Im [zf"(z)/f'(z)]| < c on |z| < 1 implies starlikeness of an analytic function f(z) on |z| < 1 with f(0) = f'(0) - 1 = 0.

• Journal of the Korean Physical Society
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• v.73 no.12
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• pp.1814-1820
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• 2018

With the publication of TRS-483 in late 2017 the IAEA has established an international code of practice for reference dosimetry in small and non-standard fields based on a formalism first suggested by Alfonso et al. in 2008. However, data on beam quality correction factors ($k^{f_{msr},f_{ref}}_{Q_{msr},Q_0}$) for the Leksell Gamma $Knife^{(R)}$ $Perfexion^{TM}$ is scarce and what little data is available was obtained under conditions not necessarily in accordance with the IAEA's recommendations. This study constitutes the first systematic attempt to calculate those correction factors by applying the new code of practice to Monte Carlo simulation using the GEANT4 toolkit. $k^{f_{msr},f_{ref}}_{Q_{msr},Q_0}$ values were determined for three common ionization chamber detectors and five different phantom materials, with results indicating that in most phantom materials, all chambers were well suited for reference dosimetry with the Gamma $Knife^{(R)}$. Similarities and differences between the results of this study and previous ones were also analyzed and it was found that the results obtained herein were generally in good agreement with earlier PENELOPE and EGSnrc studies.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.287-303
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• 1999

The general solution of the functional equation f1(pr, qs) + f2(ps, qr) = g(p,q) + h(r,s) for p, q, r, s $\in$] 0, 1[will be investigated without any regularity assumptions on the unknown functions f1, f2, g, h:]0.1[->R.

• Journal of the Chungcheong Mathematical Society
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• v.23 no.2
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• pp.349-362
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• 2010

We establish the various relationships among the integral transform ${\mathcal{F}}_{{\alpha},{\beta}}F$, the convolution product $(F*G)_{\alpha}$ and the first variation ${\delta}F$ for a class of functionals defined on K(Q), the space of complex-valued continuous functions on $Q=[0,S]{\times}[0,T]$ which satisfy x(s, 0) = x(0, t) = 0 for all $(s,t){\in}Q$. And also we obtain Parseval's and Plancherel's relations for the integral transform of some functionals defined on K(Q).

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.6
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• pp.105-113
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• 2006

This paper presents the results of an experimental investigation carried out to evaluate the mechanical properties of concrete mixtures in which fine(S) and coarse(G) aggregate was fully replaced with fly ash(FA). And flowability reduction problem in a large amount of fly ash concrete settled addition water($W_f$) in concrete mixture. In the test, water-cement ratio($W_c/C$) was 0.35, 0.45, and water-fly ash ratio($W_f/FA$) was 0.35, 0.45. The fly ash replacement is two different method of P and Q. The P method is mix property that the fly ash and addition water($W_f$) weight is equal to the aggregate weight [ $FA+W_f$ = G (or S)]. The Q method is mix property that fly ash is equal to aggregate weight, and added addition water($W_f$) [$FA+W_f$ > G (or S)]. Test were performed for properties of fresh concrete and compressive strength were determined at 3, 7, 28 and 91 days. The result, compressive strength was improvement that $W_c/C=0.35$, $W_f/FA=0.35$ and fine aggregate replacement in P method series than others. The flowability at Q method was improvement result than P method, but compressive strength was not. Test results indicate significant improvement in the strength properties and flowability of plain concrete by the inclusion of fly ash as fully replacement of fine and coarse aggregate, and can be effectively the fly ash replacement method.