• 한국미생물·생명공학회지
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• 제19권2호
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• pp.193-199
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• 1991

The effects of pH on the cell growth, the elaboration of pullulan, and the morphology of Aureobasidium pullulans IFO 4464 were examined. A. pulluans grew in yeast-like form at constant pH7.5 and in mycelial form at constant pH2.5. At the both pH conditions, the elaboration of pullulan was very low, about 6.0~6.5g/l. The mixture of yeast-like form and mycelial form of cells was found at the constant pH4.5, at which condition, the elaboration of pullulan was high, about 24.5g/l. The pH shift experimemts showed that the specific production rates of pullulan were 0.048($hr^{-1}$)for the mycelial form and 0.058($hr^{-1}$)for the yeast like form, which indicated that the yeast-like form has the similar, only slightly higher, biosynthetic activity of pullulan to the mycelial form at pH4.5 and the pH of culture broth is more important factor for the elaboration of pullulan than the morphology of A. pullulans.

• 한국군사과학기술학회지
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• 제25권5호
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• pp.545-551
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• 2022

We proposed a design method for constant current pyro squib circuit. The current method using N MOSFET for the stability problem has a weakness of the current change, requiring a new design. This paper identified the problem with conventional squib circuit where the current is reduced by 25 % when maximum resistance is 3 ohms. Thus, we proposed a stable constant current driving circuit using P MOSFET and PNP BJT. We confirmed stable constant circuit operation through simulations and measurements of the proposed circuit design where the current did not change until the resistance reached 3 ohms.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1673-1678
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• 2014

The interactive inhibitory effects of pH and chloride on the catalysis of laccase from Trametes versicolor were investigated by studying the alteration of inhibition characteristics of sodium chloride at different pHs for the oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid). At pH 3.0, the addition of sodium chloride (50 mM) brought about a 40-fold increase in $K{_m}^{app}$ and a 4-fold decrease in $V_{max}{^{app}}$. As the pH increased to 7.0, the inhibitory effects of sodium chloride became significantly weakened. The mixed-inhibition mechanism was successfully used to quantitatively estimate the competitive and uncompetitive inhibition strengths by chloride at two different pHs (pH 3.0 and 6.0). At pH 3.0, the competitive inhibition constant, $K_i$, was 0.35 mM, whereas the uncompetitive inhibition constant, $K{_i}^{\prime}$, was 18.1 mM, indicating that the major cause of the laccase inhibition by chloride is due to the competitive inhibition step. At a higher pH of 6.0, where the inhibition of the laccase by hydroxide ions takes effect, the inhibition of the laccase by chloride diminished to a great extent, showing increased values of both the competitive inhibition constant ($K_i=23.7mM$) and uncompetitive inhibition constant ($K{_i}^{\prime}=324mM$). These kinetic results evidenced that the hydroxide anion and chloride share a common mechanism to inhibit the laccase activity.

• 제어로봇시스템학회논문지
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• 제12권12호
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• pp.1173-1177
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• 2006

Using an inner P controller, a tuning rule useful for processes with wide ratios of time delay over time constant is proposed. Internal model control method and pole assignment method are utilized. It can be used for processes with wide range of the ratio of time delay to time constant without incovenience to choose different tuning rules.

• 대한수학회보
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• 제56권4호
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• pp.841-852
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• 2019

We establish the generalized Myers theorem for Finsler manifolds under integral Ricci curvature bound. More precisely, we show that the forward complete Finsler n-manifold whose part of Ricci curvature less than a positive constant is small in $L^p$-norm (for p > n/2) have bounded diameter and finite fundamental group.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.494-496
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• 2000

The properties of piezoelectric and dielectric for 0.05Pb$(Mn_{0.4}W_{0.2}Nb_{0.4})O_3$ - $0.95PbZr_{x}Ti_{1-x}O_{3}$ compositions have been investigated. In the composition of 0.05Pb$(Mn_{0.4}W_{0.2}Nb_{0.4})O_3$-$0.95PbZr_{0.51}Ti_{0.49}O_{3}$, the values of $k_p$ and ${\varepsilon_{33}}^T/{\varepsilon}_0$ are maximized, but $Q_m$ was minimized ($k_p$=56.5[%], $Q_m$=1130, $d_{33}$=258[pC/N], ${\varepsilon_{33}}^T/{\varepsilon}_0$=1170). The grain size was suppressed and the uniformity of gram was improved at the $1100[^{\circ}C]$. Dielectric constant increase at the Ti rich, but decrease at the Zr rich after poling. Because the dielectric constant after poling is determined by compromising effects between dipole switching and electostriction inducing stress(dielectric constant increasing factor) and dipole rotation to the poling direction (dielectric constant decreasing factor).

• 한국세라믹학회지
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• 제37권5호
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• pp.511-515
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• 2000

The effect of Ba2+ ion dissolution with different pH and amount of PAA on microstructural changes of green and sintered bodies and its electrical properties was studied in aqueous nano-size BaTiO3 slurry system. The dissolution of Ba2+ was least at strong base, pH 10.8 and by addition of amount of 0.15 wt% PAA. The green body with the lowest of dissolution of Ba2+ at pH 10.8 and 0.15 wt% PAA had minimum values of average pore size, 40nm and shown high increase of sintered density. The compact sintered at 125$0^{\circ}C$ for 2 hr with highest Ba2+ dissolution had low density and dielectric constant due to abnormal grian growth. However, the sintered body with the lowest Ba2+ dissolution had high sintered density and then shown high dielectric constant.

• East Asian mathematical journal
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• 제14권1호
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• pp.63-76
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• 1998

we consider the hp-version to solve non-constant coefficients elliptic equations $-div(a{\nabla}u)=f$ with Dirichlet boundary conditions on a bounded polygonal domain $\Omega$ in $R^2$. In [6], M. Suri obtained an optimal error-estimate for the hp-version: ${\parallel}u-u^h_p{\parallel}_{1,\Omega}{\leq}Cp^{(\sigma-1)}h^{min(p,\sigma-1)}{\parallel}u{\parallel}_{\sigma,\Omega}$. This optimal result follows under the assumption that all integrations are performed exactly. In practice, the integrals are seldom computed exactly. The numerical quadrature rule scheme is needed to compute the integrals in the variational formulation of the discrete problem. In this paper we consider a family $G_p=\{I_m\}$ of numerical quadrature rules satisfying certain properties, which can be used for calculating the integrals. Under the numerical quadrature rules we will give the variational form of our non-constant coefficients elliptic problem and derive an error estimate of ${\parallel}u-\tilde{u}^h_p{\parallel}_{1,\Omega}$.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.255-259
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• 1998

This study was designed to evaluate the economic analysis of channel catfish production in 1998 based on fish value and total feed cost. Catfish received higher protein feeds with lesser amount based on the dietary protein levels, but received the constant total protein input for all treatments. Weight gain per pond for treatment 1 $(28\%\;protein,\;100\%\;of\;satiation)$ was higher (P<0.10) than for treatment 3 $(36\%\;protein,\;77.8\%\;of\;satiation)$, but not significantly higher than for treatment 2 $(32\%\;protein,\;87.5\%\;of\;satiation)$ at constant DE. At constant DE/P (treatments 4, 2 and 5), weight gain per pond for treatment 5 $(36\%\;protein,\;77.8\%\;of\;satiation)$ was lower (P<0.10) than for treatment 2, but not significantly lower than for treatment 4 $(28\%\;protein,\;100\%\;of\;satiation)$. At constant DE, feed conversion slightly improved as dietary protein level increased from $28\%\;to\;32\%$ and feed allowance decreased by $12.5\%$, but did not improve further as dietary protein level increased from $28\%\;to\;36\%$ and feed allowance decreased by $22.2\%$. At constant DE/P, feed conversion improved as dietary protein level increased from $28\%\;to\;32\%$ increased and feed allowance decreased by $12.5\%$, but did not improve as dietary protein level increased from $28\%\;to\;36\%$ and feed allowance decreased by $22.2\%$ Total feed cost for treatment 1 was slightly, but not significantly higher than for treatments 2 and 3 at constant DE. At constant DE/P, total feed cost for treatment 5 was higher (P<0.05) than for treatment 2, but not significantly higher than for treatment 4. Total value of fish ($ /ha) produced for treatment 1 was highest and lowest was for treatment 5. Return above feed cost was highest for treatment 1 and nearly the same as treatment 2. Return over feed cost for treatments 3 and 4 were slightly lower than for treatments 1 and 2. Economic analysis showed that feeding fish the diet containing $28\%$ protein and 3.08 kcal/g DE to satiation and the diet containing $32\%$ protein and 3.08 kcal/g DE to $87.5\%$ of satiation produced the highest profit to farmer.

• 한국정보과학회논문지:시스템및이론
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• 제29권12호
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• pp.640-647
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• 2002

본 논문에서는 에지 가시성에 관련된 문제를 재구성 가능한 메쉬(RMESH)에서 상수 시간에 해결하는 것을 고려한다. 에지 가시성에 관련된 기본적인 문제들로 다음의 세 가지 문제를 살펴볼 수 있다. 첫째, 주어진 다각형이 어떤 에지로부터 가시적인가를 판별하라. 둘째, 주어진 다각형을 볼 수 있는 모든 에지를 구하라. 셋째, 주어진 다각형에서 어떤 에지로부터의 가시적인 영역, 즉, 가시성 다각형을 구하라. 이들 문제를 상수 시간에 해결하기 위하여 본 논문에서는 두 에지 사이의 가시성에 관한 다음의 문제를 고려한다: 단순 다각형 P의 두 에지 e와 f가 주어져 있을 때 e로부터 가시적인 f의 영역을 구하라. 본 논문에서는 이 문제를 N-N RMESH에서 상수 시간에 해결하는 알고리즘을 제시한다. 여기서 N은 P의 정점의 개수이다. 이 알고리즘을 이용하면 에지 가시성에 관련된 기본적인 문제들을 모두 RMESH에서 상수시간에 해결할 수 있다. 특히, 세 번째 문제를 N-$N_2$ RMESH에서 상수 시간에 해결하는 것이 가능하다.