• KSBB Journal
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• 제24권4호
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• pp.353-360
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• 2009

본 연구에서는 혐기조 및 무산소조, 호기조로 구성된 상향류식 고정상 담체 반응장치와 호기조로 고정상 담체 대신에 유동상 담체를 사용한 Loop Reactor로 이루어진 장치에서 생활하수를 이용하여 성능실험을 수행한 후 HRT에 따른 유기물 및 T-N, T-P 등 오염물질의 제거 특성을 비교 분석하였다. 두 반응기 모두 평균 BOD 제거율과 SS 제거율은 HRT가 증가함에 따라 증가하다가 HRT 16 h 이상에서는 일정한 수치를 나타내고 있으며 HRT 16 h에서 고정상 담체 반응기와 Loop Reactor의 평균 BOD 제거율은 각각 86.6%, 90.9%이었으며 평균 SS 제거율은 각각 78.0%, 88.2%로 Loop Reactor의 경우가 각각 4.3%, 10.2%의 더 높은 BOD와 SS 제거율을 나타내었다. 또한 평균 $COD_{Cr}$, 제거율 및 평균 $COD_{Mn}$ 제거율은 BOD와 SS 제거율과 마찬가지로 HRT가 증가함에 따라 증가하다가 HRT 16 h에서 일정한 수치를 나타내고 있으며 고정상 담체 반응기와 Loop Reactor의 평균 $COD_{Cr}$, 제거율은 각각 63.5%, 75.2%이었으며 평균 $COD_{Mn}$ 제거율은 각각 60.7%, 73.6%로 Loop Reactor의 경우가 11.7%, 12.9% 더 높은 제거율을 나타내었다. 반면에 평균 T-N 제거율 및 T-P 제거율은 두 반응기 모두 HRT가 증가함에 따라 제거율은 계속 증가하는 양상을 보여주고 있으며 HRT 16 h에서 Loop Reactor의 경우 평균 T-N 제거율 및 평균 T-P 제거율은 각각 33.6%, 54.5%로 고정상 담체 반응기보다 14.1%, 10.8%의 더 높은 제거율을 나타내었다. 이상의 결과에서 Loop Reactor가 성능이 훨씬 더 우수하였으며 최적 HRT는 16 h임을 알 수 있었다.

• Journal of applied mathematics & informatics
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• 제31권3_4호
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• pp.565-575
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• 2013

Let H be a real Hilbert space and let T : H ${\rightarrow}$ H be a Lipschitz pseudocontractive mapping. We introduce a modified Ishikawa iterative algorithm and prove that if $F(T)=\{x{\in}H:Tx=x\}{\neq}{\emptyset}$, then our proposed iterative algorithm converges strongly to a fixed point of T. No compactness assumption is imposed on T and no further requirement is imposed on F(T).

• Journal of applied mathematics & informatics
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• 제38권1_2호
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• pp.57-64
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• 2020

Let R ⊆ T be an ascending chain of commutative rings with identity and H(R, T) (resp., h(R, T)) the composite Hurwitz series ring (resp., composite Hurwitz polynomial ring). In this article, we give some conditions for the rings H(R, T) and h(R, T) to be PS-rings.

• 대한수학회논문집
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• 제9권4호
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• pp.819-823
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• 1994

If H is a Hilbert space, then an operator $T : D(T) \subset H \to H$ is said to be monotone if $$ (x-y, Tx-Ty) \geq 0$$ for any x, y in D(T). Many authors [1], [4] obtained the existence theorem for the equation $y = x + Tx$ for x, given an element y in H and a monotone operator T. On the other hand some iterative methods were applied to the approximations for the solution of the above equation [6], [8]. For example Bruck [2] obtained the iterative solution of the above equation with an explicit error estimate as follows.

• 대한수의학회지
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• 제45권2호
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• pp.245-250
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• 2005

This study was carried out to find out how space allowance affect the social behavior of Korean native cattle (Bos taurus coreanae) steers. Twelve Korean native cattle (Bos taurus coreanae) steers were used as subjects, each of which was 30-month-old and observation period was from June to July 2003. Five (T1) and seven (T2) steers were allotted to two pens of $5m{\times}10m$ in a building with slate roof and open sides respectively. They were fed at 09:00 h and 16:00 h, twice a day. The behaviors of steers were recorded from 06:00 h to 17:00 h, using two color CCD cameras (Samsung SDC-411, Korea), one B/W CCD cameras (Samsung SBC-340, Korea), one multiplexer (Samsung SDM-081, Korea) and a time lapse VCR (Samsung SRV-30, Korea). The behaviors of each steer were recorded every 2 min using an instantaneous point sampling method. While the mean percentage of time budget in WA of T1 was lower than that of T2 (p<0.05), the mean percentage of time budget in SF of T1 was higher than that of T2 (p<0.05). When it gets hot, steers in T1 rested from 10:00 h to 14:00 h when it gets cool, showing 40~80% of LD rate while steers in T2 rested from 12:00 h, when it very hot to 17:00 h, showing 20~50% of LD rate, which is relatively low. Steers in T1 were fed from 06:00 h to 08:00 h when it was cool and from 16:00 h to 18:00 h, showing 20~45% of EA rate while steers in T2 were fed from 08:00 h to 14:00 h when it was hot, showing 25~50% of EA rate. In conclusion, it turned out that the number of steers affected their social behavior, and T1 was better environment than T2 in terms of welfare.

• 대한수학회보
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• 제39권1호
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• pp.141-151
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• 2002

Let X and Y be real Banach spaces and $\varepsilon$, p $\geq$ 0. A mapping T between X and Y is called an ($\varepsilon$, p)-isometry if ｜∥T(x)-T(y)∥-∥x-y∥｜$\leq$ $\varepsilon$∥x-y∥$^{p}$ for x, y$\in$X. Let H be a real Hilbert space and T : H longrightarrow H an ($\varepsilon$, p)-isometry with T(0) = 0. If p$\neq$1 is a nonnegative number, then there exists a unique isometry I : H longrightarrow H such that ∥T(x)-I(y)∥$\leq$ C($\varepsilon$)(∥x∥$^{ 1+p)/2}$+∥x∥$^{p}$ ) for all x$\in$H, where C($\varepsilon$) longrightarrow 0 as $\varepsilon$ longrightarrow 0.

• 한국패류학회지
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• 제12권2호
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• pp.91-97
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• 1996

바윗굴의 산란유발 및 종묘생산을 위한 생물학적 기초자료를 얻고자 자극방법별 효과와 난발생 및 유생사육에 미치는 수온의 영향에 관하여 실험한 결과, 자극방법별 산란유발은 정자현탁액 첨가구에서 가장 많은 산란량과 높은 수정률을 나타냈고, 난발생 및 유생사육의 각 단계에 이르기까지의 수온(T, $^{\circ}C$)에 따른 발생속도(h, 시간)는 수온이 높을 수록 빨랐으며, 그 관계식은 다음과 같다. 담륜자기 :1/h= 0.0069T - 0.0950(r=0.9447)D형 유생 :1/h= 0.0006T - 0.0045(r=0.9288)초기 각정기 유생:1/h= 0.0002T - 0.0019(r=0.9358)후기 각정기 유생:1/h= 0.0002T - 0.0022(r=0.9868)부착기 유생:1/h= 0.0001T - 0.0013(r=0.9897)또한 바윗굴의 수온과 난발생 속도와의 관계에서 추정된 난발생의 생물학적 영도는 평균 10.96$^{\circ}C$였으며, 수온별 유생사육시 바윗굴의 생존율은 24$^{\circ}C$에서 6.8%로 가장 좋았다.

• 충청수학회지
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• 제21권3호
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• pp.339-345
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• 2008

We prove the existence of the positive solution for the nonlinear system of suspension bridge equations with Dirichlet boundary condition and periodic condition $$\{u_{tt}+u_{xxxx}+av^+=1+{\epsilon}_1h_1(x,t)\text{ in }(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,\\v_{tt}+v_{xxxx}+bu^+=1+{\epsilon}_2h_2(x,t)\text{ in }(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,$$ where $u^+={\max}\{u,0\},\;{\epsilon}_1,\;{\epsilon}_2$ are small numbers and $h_1(x,t)$, $h_2(x,t)$ are bounded, ${\pi}$-periodic in t and even in x and t and ${\parallel}h_1{\parallel}={\parallel}h_2{\parallel}=1$.

• Korean Journal of Mathematics
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• 제16권3호
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• pp.355-362
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• 2008

We prove the existence of a unique positive solution for a class of systems of the following nonlinear suspension bridge equation with Dirichlet boundary conditions and periodic conditions $$\{{u_{tt}+u_{xxxx}+\frac{1}{4}u_{ttxx}+av^+={\phi}_{00}+{\epsilon}_1h_1(x,t)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,\\{v_{tt}+v_{xxxx}+\frac{1}{4}u_{ttxx}+bu^+={\phi}_{00}+{\epsilon}_2h_2(x,t)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,$$ where $u^+={\max}\{u,0\},\;{\epsilon}_1,\;{\epsilon}_2$ are small number and $h_1(x,t)$, $h_2(x,t)$ are bounded, ${\pi}$-periodic in t and even in x and t and ${\parallel} h_1{\parallel}={\parallel} h_2{\parallel}=1$. We first show that the system has a positive solution, and then prove the uniqueness by the contraction mapping principle on a Banach space

• IMMUNE NETWORK
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• 제10권5호
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• pp.164-172
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• 2010

Background: We tested the hypothesis that dengue haemorrhagic fever (DHF) is associated with a $T_H1$-skewed immune response as opposed to dengue fever (DF). Methods: We estimated intracellular (in T-cells) and serum levels of designate $T_H1/T_H2$ cytokines [interferon-${\gamma}$ (IFN-${\gamma}$), interleukin-4 (IL-4), and tumor necrosis factor-${\alpha}$] and macrophage inflammatory protein-$1{\alpha}$ (MIP-$1{\alpha}$) at admission, 48h, and day 5 in 20 adults with dengue (DF=10, DHF=10) and 10 dengue-naive healthy controls. Results: At admission, intracellular IFN-${\gamma}$/IL-4 ratio in CD4+ T-cells and proportion of MIP-$1{\alpha}$-positive CD8+ T-cells were significantly higher in patients with DHF [7.21 (5.36~10.81) vs. 3.04 (1.75~4.02); p=0.011 and 6.2% (3.2~8.2%) vs. 2.4% (2.0~3.6%); p=0.023]. The latter showed a significant positive correlation with IFN-${\gamma}$/IL-4 ratio in CD4+ T-cells (Spearman's rho=0.64; p=0.003), percentage-change in haematocrit (rho=0.47; p=0.048), and serum alanine amino-transferase level (rho=0.61; p=0.009). Conclusion: We conclude that DHF is associated with a $T_H1$-skewed immune response. Further, MIP-$1{\alpha}$ in CD8+ T-cells is an important immunologic correlate of disease severity in dengue.