• Kyungpook Mathematical Journal
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• v.58 no.2
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• pp.307-318
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• 2018

In this paper, we obtain $Fekete-Szeg{\ddot{o}}$ inequalities for certain class of meromorphic functions f(z) for which $-{\frac{(1-{\frac{{\alpha}}{q}})qzD_qf(z)+{\alpha}qzD_q[zD_qf(z)]}{(1-{\frac{{\alpha}}{q}})f(z)+{\alpha}zD_qf(z)}{\prec}{\varphi}(z)$(${\alpha}{\in}{\mathbb{C}}{\backslash}(0,1]$, 0 < q < 1). Sharp bounds for the $Fekete-Szeg{\ddot{o}}$ functional ${\mid}{\alpha}_1-{\mu}{\alpha}^2_0{\mid}$ are obtained.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.635-637
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• 2012

In Gen-2 Q-algorithm, the value of initial $Q_{fp}$ and weight C is not defined in the standard. If we let the initial $Q_{fp}$ be large or small, the number of empty slot will be large during the initial query round or almost all the slots will be collided, respectively. Also, if the reader selects an inappropriate weight, there are a lot of empty or collided slots. As a result, it is anticipated that the performance will be declined because the frame size does not converge to the optimal point quickly during the query round. In this paper, we analyze how the performances of Gen-2 Q-algorithm will be affected by the weight and initial slot-count size.

• Journal of Magnetics
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• v.16 no.3
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• pp.197-200
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• 2011

Using the full potential linearized augmented plane wave (FLAPW) method, the influences of uniform and tetragonal strains on the magnetic state have been explored for chemically ordered bulk $L1_2$ $FePt_3$. The ordered state displays antiferromagnetic $Q_1$ (AFM-$Q_1$) state but it transitions into antiferromagnetic $Q_2$ (AFM-$Q_2$) state at about 10% uniform strain. The ferromagnetic (FM) state is observed at 11% uniform strain. For tetragonal strain, it is also seen that the transition from AFM-$Q_1$ to AFM-$Q_2$ depends on the strength and direction of the applied strain. The FM state does not appear in this case. Magnetocrystalline anisotropy (MCA) calculations for tetragonal distortion reveal that the spin reorientation transition occurs. In addition, we find that the direction of magnetization and the magnitude of magnetic anisotropy energy strongly depend on the c/a ratio.

• Communications of the Korean Mathematical Society
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• v.37 no.2
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• pp.445-454
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• 2022

Using the concept of the strong differential subordination introduced in [2], we find conditions on the functions θ, 𝜑, G, F such that the first order strong subordination θ(p(z)) + $\frac{G(\xi)}{\xi}$zp'(z)𝜑(p(z)) ≺≺ θ(q(z)) + F(z)q'(z)𝜑(q(z), implies p(z) ≺ q(z), where p(z), q(z) are analytic functions in the open unit disk 𝔻 with p(0) = q(0). Corollaries and examples of the main results are also considered, some of which extend and improve the results obtained in [1].

• Communications of the Korean Mathematical Society
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• v.39 no.3
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• pp.785-802
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• 2024

Given M a monoid with a neutral element e. We show that the solutions of d'Alembert's functional equation for n × n matrices Φ(pr, qs) + Φ(sp, rq) = 2Φ(r, s)Φ(p, q), p, q, r, s ∈ M are abelian. Furthermore, we prove under additional assumption that the solutions of the n-dimensional mixed vector-matrix Wilson's functional equation $$\begin{cases}f(pr, qs) + f(sp, rq) = 2\phi(r, s)f(p, q),\\Φ(p, q) = \phi(q, p),{\quad}p, q, r, s {\in} M\end{cases}$$ are abelian. As an application we solve the first functional equation on groups for the particular case of n = 3.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.121-125
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• 1994

The antioxidant activity of gingerol according to temperature on soybean oil were examined by measuring peroxide value(POV). The induction period(IP) of soybean oil was 45; 276.0, 65; 17.0 and 105$^{\circ}C$ : 4.7 hours respectively by-measuring POV. The relative antioxidant effectiveness(RAE) of ginge-rol group were 45; 191, 65; 200, 65: 150, 85: 132 and 105$^{\circ}C$;106%. 'The activation energies(Ea) and temperature coefficients(Q10) for Arrhenius equations at 45∼105$^{\circ}C$, was estimated in order to find out the influence of temperature on the oxidation of soybean oil contai-ning various antioxidants. The soybean oil was more unstable at 45∼65$^{\circ}C$ than at 65∼105$^{\circ}C$ in the Ea and Q10. The soybean oils containing gingerol were more stable than the control group at 45∼105$^{\circ}C$, however, BHT group was unstable compared to gingerol group at 85∼105$^{\circ}C$.

• Bulletin of the Korean Mathematical Society
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• v.37 no.4
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• pp.803-810
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• 2000

Let N($d_1,...,{\;}d_n;c_1,...,{\;}c_n$) be the number of solutions $(x_1,...,{\;}x_n){\in}F^{n}_p$ of the diagonal equation $c_lx_1^{d_1}+c_2x_2^{d_2}+{\cdots}+c_nx_n^{d_n}{\;}={\;}0{\;}n{\geq},{\;}c_j{\;}{\in}{\;}F^{*}_q,{\;}j=1,2,...,{\;}n$ where $d_j{\;}>{\;}1{\;}and{\;}d_j{\;}$\mid${\;}q{\;}-{\;}1$ for all j = 1,2,..., n. In this paper, we find all n-tuples ($d_1,...,{\;}d_n$) such that the reduced form of ($d_1,...,{\;}d_n$) and N($d_1,...,{\;}d_n;c_1,...,{\;}c_n$) are the same as in the theorem obtained by Sun Qi [3]. Improving this, we also get an explicit formula for the number of solutions of the diagonal equation, unver a certain natural restriction on the exponents.

• Publications of The Korean Astronomical Society
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• v.12 no.1
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• pp.99-109
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• 1997

We obtained the CN($\Delta_V=0$) and $C_2(\Delta_V=0,\;\pm1$) spectra of comet Hale-Bopp(C/1995 O1) at the Kyunghee Observatory and Bohyunsan Astronomical Observatory between March 7 and May 12, 1997 The fluxes for each molecular band were measured and then the production rates and column densities of CN and $C_2$ were calculated using a simple model. The resultantproduction rates of CN and $C_2$ are logQ(CN)=27.4 at r=0.94 AU(preperihelion) and $logQ(C_2)=27.3$ at r=0.94 AU(postperihelion), respectively.

• Journal of Ecology and Environment
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• v.35 no.3
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• pp.203-212
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• 2012

The physiological effects of elevated $CO_2$ concentration and temperature were examined for Quercus gilva and Q. glauca grown under control (ambient $CO_2$ and temperature) and treatment (elevated $CO_2$ and temperature) conditions for 39 months. The objective of the study was to measure the long-term responses, in physiological parameters, of two oaks species exposed to elevated $CO_2$ and temperature. The photosynthetic rate of Q. gilva was found to be decreased, but that of Q. glauca was not significantly affected, after long-term exposure to elevated $CO_2$ and temperature. Stomatal conductance of Q. glauca was reduced by 21.7%, but that of Q. gilva was not significantly affected, by long-term exposure to $CO_2$ and temperature. However, the transpiration rate of the two oak species decreased. Water use efficiency of Q. gilva was not significantly affected by elevated $CO_2$ and temperature, while that of Q. glauca was increased by 56.6%. The leaves of Q. gilva grown under treatment conditions had an increased C:N ratio due to their reduced nitrogen content, while those of Q. glauca were not significantly affected by long-term exposure to elevated $CO_2$ and temperature. These results suggest that the long-term responses to elevated $CO_2$ and temperature between Q. gilva and Q. glauca are different, and that Q. gilva, the endangered species, is more sensitive to elevated $CO_2$ and temperature than Q. glauca.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.62-62
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• 2023

강우가 지표면 아래로 침투할 때 초기에는 투수층이 불포화 상태이어서 부압이 작용하면서 침투할 것이다. Richards 식(Richards, 1931)을 써서 불포화 투수층의 침투를 모의할 수 있다. 강우가 지속되는 동안 하상 아래 어느 구간은 포화 상태가 되어 Richards 식을 더 이상 사용할 수 없다. 하지만 현재까지의 연구는 Richards 식을 사용하여 침투를 모의하는 오류를 범하고 있다. 강우에 의한 침투를 예측할 때 지표면에서의 침투율 q_b 가 필요한 데 현존하는 연구에서는 Horton 식(Horton, 1941)을 사용하여 초기 침투율 f_o 와 장시간 후 침투율 f_c 와 시간에 따라 지수함수로 감소하는 계수 k 의 3가지 계수값을 실험이나 현장 관측값에서 찾아서 쓰고 있다. 그런데, 이 계수값은 강우강도 r_i 가 클수록 침투율 q 가 커지는 물리 현상을 반영하지 못하는 한계가 있다. 본 연구에서 먼저 포화 투수층에서의 침투를 모의하는 식을 개발하였다. 지표면 아래에서 불포화 투수층에는 Richards식을 사용하고 포화 투수층에는 개발한 식을 사용하여 침투를 모의하였다. 또한 지표면에서의 침투율 q_b 를 구하는 공식을 개발하였다. 하상에서의 침투율의 최대값은 $q_{bmax}=-{\lambda}{\sqrt{2g(s-b)}}$ 일 것이다. 여기서 λ 는 투수층의 공극율, s 는 유출수면의 위치, b 는 지표면의 위치이다. 지표면에서의 침투율의 최소값 q_bmin 은 지표면 바로 아래 지점에서의 침투율일 것이다. 지표면에서의 침투율 q_b 로 q_bmax 와 q_bmin 사이의 적절한 값을 선택한다. 강우강도를 r_i 라고 하면 지표면 위 유출수의 연속방정식은 다음과 같다: $s-b={\int}(r_i-{\mid}q_b{\mid})dt$. 즉, 유출수면의 위치 s 는 강우강도 r_i 가 클수록 또는 지표면에서의 유출율의 크기 |q_b| 가 작을수록 크다. 또한 지표면에서의 침투율 q_b 와 지표면 아래에서의 침투율 q 는 s - b 가 클수록 크다. 따라서, 강우강도 r_i 가 클수록 침투율 q_b, q 가 큰 현상이 잘 반영되었다. 강우-침투-유출 모형실험을 수행하여 강우강도에 따라 침투율과 유출량이 다른 현상을 관측하여 수치실험 결과와 비교·검증하였다.