• 상하수도학회지
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• 제35권3호
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• pp.197-204
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• 2021

In MBR, extracellular polymeric substance (EPS) is known as an important factor of fouling; soluble EPS (sEPS) affects internal contamination of membrane, and bound EPS (bEPS) affects the formation of the cake layer. The production of EPS changes according to the composition of influent, which affects fouling characteristics. Therefore, in this study, the effects of the F/M ratio on the sEPS concentration, bEPS content, and fouling were evaluated. The effects of F/M ratio on the amount and composition of EPS were confirmed by setting conditions that were very low or higher than the general F/M ratio of MBR, and the fouling occurrence characteristics were evaluated by filtration resistance distribution. As a result, it was found that the sEPS increased significantly with the increase of the F/M ratio. When the substrate was depleted, bEPS content decreased because bEPS was hydrolyzed into BAP and seemed to be used as a substrate. In contrast, when the substrate is sufficient, UAP (utilization-associated products) was rapidly generated in proportion with the consumption of the substrate. UAP has a relatively higher Protein/Carbohydrate ratio (P/C ratio) than BAP, and this means, it has a higher adhesive force to the membrane surface. As a result, UAP seems like causing fouling rather than BAP (biomass-associated products). Therefore, R_f (Resistance of internal contamination) increased rapidly with the increase of UAP, and R_c (Resistance of cake layer) increased with the accumulation of bEPS in proportion, and as a result, the fouling interval was shortened. According to this study, a high F/M ratio leads to an increment in UAP generation and accumulation of bEPS, and by these UAP and bEPS, membrane fouling is promoted.

• 대한전자공학회논문지TC
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• 제45권1호
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• pp.110-114
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• 2008

본 논문에서는 단일 FET를 이용하여 2.14GHz/5.2GHz 이중대역 고효율 Class F 전력증폭기를 설계 구현하였다. 전송선로를 이용하여 초기의 정합값을 적절히 이동시켜 하나의 능동소자로 2.14GHz/5.2GHz의 이중대역에서 동작되는 전력증폭기를 설계하였으며, 2.14GHz에서 32.65dBm의 출력과 11dB의 출력이득 36%의 전력효율을, 5.2GHz에서 7dB의 출력이득의 특성을 보였다. 고조파를 제어 회로를 설계하여 증폭기의 출력단에 추가 하여 Class F로 동작하는 이중대역 전력증폭기를 설계 하였다. 이중대역 Class F 전력증폭기는 2.14GHz에서 9.9dB의 출력이득과 30dBm의 출력, 55%의 전력효율을 가졌으며, 5.2GHz에서 11.7dB의 출력이득을 갖는 특성을 보였다. 고조파 제어 회로를 이용한 이중대역 Class F 전력증폭기가 전력효율을 향상시킴을 보였다.

• Advances in Traditional Medicine
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• 제9권1호
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• pp.20-38
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• 2009

The objectives of this study were to determine the effect of herb formula HDDM, a modification of Huangdan decoction that has been shown to be effective in the treatment of glomerulonephritis and chronic renal failure, on the blood glucose levels in multiple low doses (MLD; 50 mg/kg for five consecutive days) of streptozotocin (STZ)-treated female B6C3F1 mice. Initial studies were performed to compare diabetes induction in five strains (e.g., B6C3F1, NOD, CD-1, C3H/HeN and C57BL/6) of mice by MLD-STZ, and immune changes following the treatment. The results suggested that the order of susceptibility to diabetes induction was NOD $\approx$ CD-1 > B6C3F1 $\approx$ C3H > C57BL/6. Furthermore, STZ modulation of T cell development, differentiation and activation might play a role in diabetes induction by MLD-STZ treatment. MLD-STZ-induced diabetes in female B6C3F1 mice was moderate, which allowed the evaluation of drug-induced protection or exacerbation of diabetes to be performed. As such, modulation of blood glucose by HDDM, which consisted of Da Huang (Radix Et Rhizoma Rhei), Huang Qi (Radix Astragali Seu Hedysari), Dan Shen (Radix Salviae Miltiorrhizae), Yin Yang Huo (Herba Epimedii), Yi Yi Ren (Semen Coicis or Coix lacryma-jobi), Mai Dong (Radix Ophiopogonis) and Shan Zhu Yu (Fructus Corni), was evaluated in MLD-STZ-treated female B6C3F1 mice. The results suggested that HDDM could lower the blood glucose levels, but it had no immunomodulatory activities. Additionally, HDDM-treated mice exhibited improved glucose tolerance. In conclusion, these studies have suggested that MLD-STZ-induced diabetes in female B6C3F1 mice is a useful model to evaluate drug modulation of diabetes, and that the herb formula HDDM possesses anti-diabetic effects.

• 한국전자통신학회논문지
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• 제12권1호
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• pp.25-30
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• 2017

본 논문에서는 음의 투자율(negative values permeability)을 가지는 CSRR(: Complementary split ring resonator)를 안테나의 그라운드면에 적용하여 이중대역에서 사용가능한 마이크로스트립 패치안테나를 최적설계하였다. SRR의 음각형태인 CSRR을 안테나의 급전선 뒷면에 배치하여 대역저지특성을 만들고 이를 이용해서 위성통신에 사용하는 L-band의 두주파수 f1(1.53GHz), f2(1.63GHz)에서 사용가능한 안테나를 제안하였다. 제안한 안테나는 마이크로스트립라인을 이용하여 배열이 가능하고 기존의 패치안테나에 비해 소형으로 제작이 가능하다. 제작된 안테나는 f1과 f2에서 각각 -12.5dB, -14.5dB의 입력반사계수와 2.0dB, -0.8dB의 이득을 얻을 수 있어 이중대역에서 충분한 성능을 나타내는 것을 확인하였다.

• Animal Systematics, Evolution and Diversity
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• 제8권1호
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• pp.35-56
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• 1992

한국 담수산 윤충류의 분류학적 연구를 위하여 1990년 3月부터 1992년 2월까지 전국 일대에 산재해 있는 댐, 호수, 저수지, 연못, 논, 웅덩이 등을 대상으로 총 205개 지점에서 채집을 실시하여 조사한바, Brachionidae과의 Brachionus속에 9아종 2변종 6형이, 그리고 Platyas속에는 1종이 밝혀졌는데, 그중 Brachionus속의 1아종 4형 : Brachionus urceolaris bennini, B. angularis f. bidens, B. quadridentatus f. rhenanus, B. forficuIa f. minor, B. forficula f. angularis가 한국 미기록으로 판명되어 기재와 함께 도판을 작성하였고, 본 연구에서 확인된 Brachionus와 Platyas속내의 종들에 대해서는 물론, 연차적인 발표를 목적으로 한국산 윤형동물에 대한 전체척언 검색표를 만들었다. 따라서 지금까지 기록된 한국산 윤충류는 총 2강 4목 14과 40속 134종, 15아종, 9변종, 9형이 된다.

• 한국의류산업학회지
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• 제13권5호
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• pp.661-671
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• 2011

This study was designed to produce rounded belt pattern and tight-skirt pattern drafting method using 3D body scan data. Subjects were thirty women in their early twenties. In order to figure out the optimum cutting points, namely, where darts are made, using CAD program, curve ratio inflection points on the horizontal curve of waist, abdomen, and hip to find 1 point in the front, two points in the back part. The average length from center front point to maximum curve ratio was 7.7 cm(46.3%) on the waist curve; 7.9 cm(39.4%) on the abdomen curve. And the average length from center back point to maximum curve ratio point was 6.9 cm(39.0%) for first dart and 11.2 cm(63.3%) for second dart on the waist curve; 8.9 cm(35.8%) for first dart and 15.7 cm(63.3%) for second dart on the hip curve respectively. The cutting lines from were made up by connecting curve inflection points. After divided using cutting lines, each patch was flattened onto the plane and all the technical design factors related with patternmaking were measured, such as dart amount, lifting amount of side waist point, etc. Based on the results of correlation analysis among these factors, regression analysis was done to produce equations to estimate the variables necessary to draw up pattern draft method; F1=F8+1.1, $F4=2.5{\times}F2+0.9$, $F5=0.9{\times}F4+1.0$, $F6=0.3{\times}F4+0.4$, $B1=0.9{\times}B8+2.3$, $B4=2.1{\times}B2+1.3$, $B5=0.9{\times}B4+3.5$, and $B6=0.3{\times}B4+0.4$.

• 대한수학회논문집
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• 제11권2호
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• pp.377-383
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• 1996

For a given separable space X which contains no copy of $C_0$ and a weakly compact T, we show that a Dunford integrable function $f : [a,b] \to X$ is intrinsically-separable valued if and only if f is McShane integrable. Also, for a given separable space X which contains no copy of $C_0$, a weakly compact T and a Dunford integrable function f we show that if there exists a sequence $(f_n)$ of McShane integrable functions from [a,b] to X such that for each $x^* \in X^*, x^*f_n \to x^*f$ a.e., then f is McShane integrable. Finally, let X contain no copy of $C_0$. If $f : [a,b] \to X$ is McShane integrable, then F is a countably additive on $\sum$.

• Animal Systematics, Evolution and Diversity
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• 제22권1호
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• pp.87-89
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• 2006

The mitochondrial cytochrome b gene of the Korean subspecies (Falco tinnunculus interstinctus) of the common kestrel has been analyzed. According to the molecular phylogeny of six subspecies of common kestrel, six subspecies of the common kestrel were divided into two clades: the first clade is composed of the South African subspecies (F. t. rupicolus) and the second clade includes 5 subspecies (F. t. tinnunculus, F. t. rufescens, F. t. interstinctus, F. t. canariensis and F. t. dacotiae) of the common kestrel. Korean subspecies, F. t. interstinctus was closely related to F. t. rufescens and original subspecies F. t. tinnunculus.

• Journal of applied mathematics & informatics
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• 제25권1_2호
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• pp.17-33
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• 2007

Suppose F is an arbitrary field. Let ${\mid}F{\mid}$ be the number of the elements of F. Let $T_{n}(F)$ be the space of all $n{\times}n$ upper-triangular matrices over F. A map ${\Psi}\;:\;T_{n}(F)\;{\rightarrow}\;T_{n}(F)$ is said to preserve idempotence if $A-{\lambda}B$ is idempotent if and only if ${\Psi}(A)-{\lambda}{\Psi}(B)$ is idempotent for any $A,\;B\;{\in}\;T_{n}(F)$ and ${\lambda}\;{\in}\;F$. It is shown that: when the characteristic of F is not 2, ${\mid}F{\mid}\;>\;3$ and $n\;{\geq}\;3,\;{\Psi}\;:\;T_{n}(F)\;{\rightarrow}\;T_{n}(F)$ is a map preserving idempotence if and only if there exists an invertible matrix $P\;{\in}\;T_{n}(F)$ such that either ${\Phi}(A)\;=\;PAP^{-1}$ for every $A\;{\in}\;T_{n}(F)\;or\;{\Psi}(A)=PJA^{t}JP^{-1}$ for every $P\;{\in}\;T_{n}(F)$, where $J\;=\;{\sum}^{n}_{i-1}\;E_{i,n+1-i}\;and\;E_{ij}$ is the matrix with 1 in the (i,j)th entry and 0 elsewhere.

• Journal of applied mathematics & informatics
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• 제27권1_2호
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• pp.97-103
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• 2009

Suppose F is a field of characteristic not 2 and $F\;{\neq}\;Z_3$. Let $M_n(F)$ be the linear space of all $n{\times}n$ matrices over F, and let ${\Gamma}_n(F)$ be the subset of $M_n(F)$ consisting of all $n{\times}n$ involutory matrices. We denote by ${\Phi}_n(F)$ the set of all maps from $M_n(F)$ to itself satisfying A - ${\lambda}B{\in}{\Gamma}_n(F)$ if and only if ${\phi}(A)$ - ${\lambda}{\phi}(B){\in}{\Gamma}_n(F)$ for every A, $B{\in}M_n(F)$ and ${\lambda}{\in}F$. It was showed that ${\phi}{\in}{\Phi}_n(F)$ if and only if there exist an invertible matrix $P{\in}M_n(F)$ and an involutory element ${\varepsilon}$ such that either ${\phi}(A)={\varepsilon}PAP^{-1}$ for every $A{\in}M_n(F)$ or ${\phi}(A)={\varepsilon}PA^{T}P^{-1}$ for every $A{\in}M_n(F)$. As an application, the maps preserving inverses of matrces also are characterized.