• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.4-4
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• 2017

Atmospheric carbon dioxide enrichment ($eCO_2$) often increases soil nitrous oxide ($N_2O$) emissions, but the underlying mechanisms are not fully understood. Emerging evidence suggests that $eCO_2$ alters plant N preference in favor of ammonium ($NH_4{^+}-N$) over nitrate ($NO_3{^-}-N$). Yet, whether and how this attributes to the enhancement of $N_2O$ emissions has not been investigated. We examined the effects of $eCO_2$ on soil $N_2O$ emissions in the presence of two N forms ($NH_4{^+}-N$ or $NO_3{^-}-N$), using wheat (Triticum aestivum L.) as a model plant. Our results showed that N forms dominated $eCO_2$ effects on plant and microbial N utilization, and thus soil $N_2O$ emissions. Elevated $CO_2$ significantly increased the rate and the sum of $N_2O$ emissions by three to four folds when $NO_3{^-}-N$, but not $NH_4{^+}-N$, was supplied. Enhanced $N_2O$ emission was related to the reduced plant $NO_3{^-}-N$ uptake in wheat. We propose a new conceptual model in which $eCO_2$-inhibition of plant $NO_3{^-}-N$ uptake and/or $CO_2$-enhancement of soil labile C enhances the N and/or C availability for denitrifiers and increases the intensity and/or the duration of $N_2O$ emissions. Together, these findings suggest that to enhance plant N use efficiency and reduce $N_2O$ emission, crop breeding and management need to consider altered plant preference of N sources under future $CO_2$ scenarios.

• 정보보호학회논문지
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• 제13권3호
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• pp.27-34
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• 2003

요즘 암호시스템을 효율적으로 수행하는 하드웨어의 개발이 관심의 대상이 되고 있다. 암호시스템의 효율적인 수행은 연산기의 효율적인 연산이 뒷받침되어야 한다. 특히 유한체 GF(2$^n$)에서의 곱셈기는 여러 연산 중에서 효율성이 고려되어야 할 핵심적인 연산이다. 이 논문에서는 유한체에서의 곱셈기를 시간 복잡도(time complexity)와 하드웨어복잡도(size complexity) 사이의 교환(trade-off)을 고려하여 기존 곱셈기$^{［5］［12］}$의 하드웨어 복잡도인 #AND(AND gate 수)= $n^2$, #XOR(XOR gate 수) = $n^2$-1 보다 개선된 #AND = [n/2], #XOR = n([n/2+1])-$\delta$$_{n}$ (n이 짝수이면$\delta$$_{n}$ =1, n이 홀수이면 $\delta$n=0)이고 두 클럭 내에 결과를 얻을 수 있는 직렬-병렬 곱셈기를 제안한다. 우리는 기존의 논문에서 제안된 곱셈기와 구조를 달리하여 공간의 제약이 있는 하드웨어에 적합한 효율적인 연산기의 구현방안을 제시한다.

• 한국가축번식학회지
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• 제6권1호
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• pp.31-35
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• 1982

A study of 188 lactations of Holstein cows in Gwangju area was undertaken to establish the shape of lactation curve during the period from October in 1980 to January in 1982. The Gammafunction described by Wood(1967) was fitted to the lactations observed. The results obtained in the present study were summarized as follows; 1. The lactation curve of the 188 lactations was expressed by the equation based on Wood's model (1967) as follows; Yn=24.5m0.0762e-0.0944n(R2=0.99) 2. The lactation curves by parity were represented by the equations as follows; Yn=18.81n0.1486e-0.0741n(R2=0.98)……………parity 1 Yn=26.51n0.1161e-0.1200n(R2=0.96)……………parity 2 Yn=26.95n0.2804e-0.1703n(R2=0.99)……………parity 3 Yn=27.92n0.1429e-0.1427n(R2=0.98)……………parity 4 Yn=22.61n0.1985e-0.1211n(R2=0.94)……………parity 5 3. The lactation curves by calving seasons were represented by the equationes as follows; Yn=27.05n0.0739e-0.1005n(R2=0.98)……………spring Yn=23.08n0.2040e-0.1202n(R2=0.98)……………summer Yn=26.81n0.0460e-0.1134n(R2=0.98)……………autumn Yn=23.40n0.1299e-0.1101n(R2=0.95)……………winter

• 한국환경농학회지
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• 제41권3호
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• pp.167-176
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• 2022

BACKGROUND: Nitrogen (N) is an important element for turfgrass (Zoysia matrella) growth; however, standard N application rate for turfgrass is not established yet. This study was conducted to evaluate the effect of N application rates on the growth and quality of turfgrass for establishment of standard N application rate. METHODS AND RESULTS: Treatments were as follows; control (0 N g/m²/month), 1N (1 N g/m²/month), 2N(2 N g/m²/month), 3N (3 N g/m²/month), 4N (4 N g/m²/month), and 5N (5 N g/m²/month). N application improved visual turfgrass quality. Compared with the control, clipping yield of all N treatments increased by 90~194%. The grass shoot weight of 3N, 4N, and 5N treatments increased by 52%, 43%, and 111%, respectively, and the stolon weight of 4N and 5N treatments increased by 412% and 201%, respectively, compared to the control. The N uptake amount and N recovery rate were estimated to be 4.10~6.28 g/m² and 14~58%, respectively. CONCLUSION(S): These results indicate that considering visual quality, clipping yield, N uptake amount, and N recovery, the application rate of 2~3 N g/m²/month was suggested to be suitable for Z. matrella production.

• 한국인터넷방송통신학회논문지
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• 제14권5호
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• pp.87-93
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• 2014

n/m=qm+r에서 에서 m=7인 단순한 경우에도 주어진 수 n이 m의 배수 판정법은 간단하지가 않다. 만약, m이 두 자리 수 이상이 되면 더욱 복잡해진다. 일반적인 배수 판정법으로 둔켈스 (Dunkels)법이 있지만 n이 컴퓨터로 처리하지 못하는 매우 큰 자리수인 경우 이 방법도 처리할 수 없다. 본 논문은 n과 m의 자리수와 무관하게 n(modm)=0 여부로 n이 m의 배수인지 여부를 검증하는 간단하면서도 정확한 방법을 제안한다. 제안된 방법은 $n=n_1n_2n_3{\cdots}n_k$, $m=m_1m_2{\cdots}m_l$에 대해 $r_1=n_1n_2{\cdots}n_l(mod m)$으로 설정하고, $r_i=r_{i-1}{\times}10+n_i(mod m)$, $i=2,3,{\cdots},k-1+1$로 n의 자리수를 1자리씩 감소시키는 방법을 적용하였다. 제안된 방법을 다양한 n,m 데이터에 적용한 결과 쉽고, 빠르며 정확한 몫과 나머지 값을 구할 수 있음을 보였다.

• East Asian mathematical journal
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• 제25권2호
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• pp.179-196
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• 2009

Let E be a uniformly convex Banach space and K a nonempty closed convex subset which is also a nonexpansive retract of E. For i = 1, 2, 3, let $T_i:K{\rightarrow}E$ be an asymptotically nonexpansive mappings with sequence ${\{k_n^{(i)}\}\subset[1,{\infty})$ such that $\sum_{n-1}^{\infty}(k_n^{(i)}-1)$ < ${\infty},\;k_{n}^{(i)}{\rightarrow}1$, as $n{\rightarrow}\infty$ and F(T)=$\bigcap_{i=3}^3F(T_i){\neq}{\phi}$ (the set of all common xed points of $T_i$, i = 1, 2, 3). Let {$a_n$},{$b_n$} and {$c_n$} are three real sequences in [0, 1] such that $\in{\leq}\;a_n,\;b_n,\;c_n\;{\leq}\;1-\in$ for $n{\in}N$ and some ${\in}{\geq}0$. Starting with arbitrary $x_1{\in}K$, define sequence {$x_n$} by setting {$$x_{n+1}=P((1-a_n)x_n+a_nT_1(PT_1)^{n-1}y_n)$$ $$y_n=P((1-b_n)x_n+a_nT_2(PT_2)^{n-1}z_n)$$ $$z_n=P((1-c_n)x_n+c_nT_3(PT_3)^{n-1}x_n)$$. Assume that one of the following conditions holds: (1) E satises the Opial property, (2) E has Frechet dierentiable norm, (3) $E^*$ has Kedec -Klee property, where $E^*$ is dual of E. Then sequence {$x_n$} converges weakly to some p${\in}$F(T).

• 대한수학회논문집
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• 제34권1호
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• pp.1-16
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• 2019

Let a, b, P, and Q be real numbers with $PQ{\neq}0$ and $(a,b){\neq}(0,0)$. The Horadam sequence $\{W_n\}$ is defined by $W_0=a$, $W_1=b$ and $W_n=PW_{n-1}+QW_{n-2}$ for $n{\geq}2$. Let the sequence $\{X_n\}$ be defined by $X_n=W_{n+1}+QW_{n-1}$. In this study, we obtain some new identities between the Horadam sequence $\{W_n\}$ and the sequence $\{X_n\}$. By the help of these identities, we show that Diophantine equations such as $$x^2-Pxy-y^2={\pm}(b^2-Pab-a^2)(P^2+4),\\x^2-Pxy+y^2=-(b^2-Pab+a^2)(P^2-4),\\x^2-(P^2+4)y^2={\pm}4(b^2-Pab-a^2),$$ and $$x^2-(P^2-4)y^2=4(b^2-Pab+a^2)$$ have infinitely many integer solutions x and y, where a, b, and P are integers. Lastly, we make an application of the sequences $\{W_n\}$ and $\{X_n\}$ to trigonometric functions and get some new angle addition formulas such as $${\sin}\;r{\theta}\;{\sin}(m+n+r){\theta}={\sin}(m+r){\theta}\;{\sin}(n+r){\theta}-{\sin}\;m{\theta}\;{\sin}\;n{\theta},\\{\cos}\;r{\theta}\;{\cos}(m+n+r){\theta}={\cos}(m+r){\theta}\;{\cos}(n+r){\theta}-{\sin}\;m{\theta}\;{\sin}\;n{\theta},$$ and $${\cos}\;r{\theta}\;{\sin}(m+n){\theta}={\cos}(n+r){\theta}\;{\sin}\;m{\theta}+{\cos}(m-r){\theta}\;{\sin}\;n{\theta}$$.

• 대한수학회지
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• 제47권2호
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• pp.263-275
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• 2010

Let {$X_n;n\;\geq\;1$} be a strictly stationary sequence of negatively associated random variables with mean zero and finite variance. Set $S_n\;=\;{\sum}^n_{k=1}X_k$, $M_n\;=\;max_{k{\leq}n}|S_k|$, $n\;{\geq}\;1$. Suppose $\sigma^2\;=\;EX^2_1+2{\sum}^\infty_{k=2}EX_1X_k$ (0 < $\sigma$ < $\infty$). We prove that for any b > -1/2, if $E|X|^{2+\delta}$(0<$\delta$$\leq$1), then $$lim\limits_{\varepsilon\searrow0}\varepsilon^{2b+1}\sum^{\infty}_{n=1}\frac{(loglogn)^{b-1/2}}{n^{3/2}logn}E\{M_n-\sigma\varepsilon\sqrt{2nloglogn}\}_+=\frac{2^{-1/2-b}{\sigma}E|N|^{2(b+1)}}{(b+1)(2b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2(b+1)}}$$ and for any b > -1/2, $$lim\limits_{\varepsilon\nearrow\infty}\varepsilon^{-2(b+1)}\sum^{\infty}_{n=1}\frac{(loglogn)^b}{n^{3/2}logn}E\{\sigma\varepsilon\sqrt{\frac{\pi^2n}{8loglogn}}-M_n\}_+=\frac{\Gamma(b+1/2)}{\sqrt{2}(b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2b+2'}}$$, where $\Gamma(\cdot)$ is the Gamma function and N stands for the standard normal random variable.

• 대한수학회지
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• 제46권5호
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• pp.895-905
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• 2009

Let $B^{n+1}$ be the unit ball in the complex vector space $\mathbb{C}^{n+1}$ with the standard Hermitian metric. Let ${\Sigma}^n={\partial}B^{n+1}=S^{2n+1}$ be the boundary sphere with the induced CR structure. Let f : ${\Sigma}^n{\hookrightarrow}{\Sigma}^N$ be a local CR immersion. If N < 3n - 1, the asymptotic vectors of the CR second fundamental form of f at each point form a subspace of the CR(horizontal) tangent space of ${\Sigma}^n$ of codimension at most 1. We study the higher order derivatives of this relation, and we show that a linearly full local CR immersion f : ${\Sigma}^n{\hookrightarrow}{\Sigma}^N$, N $\leq$ 3n-2, can only occur when N = n, 2n, or 2n + 1. As a consequence, it gives an extension of the classification of the rational proper holomorphic maps from $B^{n+1}$ to $B^{2n+2}$ by Hamada to the classification of the rational proper holomorphic maps from $B^{n+1}$ to $B^{3n+1}$.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.297-300
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• 1999

The protonation constants of the macrocyclic ligands, 1,4-dioxa-7,10,13,16-tetraaza-cyclooctadecane-N,N',N",N"'-tetra(acetic acid) [N-ac4[18]aneN402] and 1,4-dioxa-7,10,13,16-tetraazacyclooctadecane-1,4-dioxa-7,10,13,16-N,N',N",N"'-tetra(methylacetic acid) [N-meac4[18]aneN4O2] have been determined by using potentiometric method. The protonation constants of the N-ac4[18]aneN4O2 were 9.31 for logK1H, 8.94 for logK2H, 7.82 for logK3H, 4.48 for logK4H and 2.94 for logK5H. And the protonation constants of the N-meac4[18]aneN4O2 were 9.34 for logK1H, 9.13 for logK2H, 8.05 for logK3H, 5.86 for logK4H, and 3.55 for logK5H. The stability constants of complexes on the divalent transition ions (Co2+, Ni2+, Cu2+, and Zn2+) and tiivalent metal ions (Ce3+, Eu3+, Gd3+, and Yb3+) with ligands N-ac4[18]-aneN4O2 and N-meac4[18]aneN4O2 have been obtained from the potentiometric data with the aid of the BEST program. The three higher values of the protonation constants for synthesized macrocyclic ligands correspond to the protonation of nitrogen atoms, and the fourth and fifth values correspond to the protonation of the carboxylate groups for the N-ac4[18]aneN4O2 and N-meac4[18]aneN4O2. The meatal ion affinities of the two tetra-azamacrocyclic ligands with four pendant acetate donor groups or methylacetate donor groups are compared. The effects of the metal ions on the stabilities are discussed, and the trends in stability constants resulting from changing the macrocyclic ring with pendant donor groups and acidity of the metal ions.