• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2609-2612
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• 2005

In this paper we proposed the real time monitoring system for power controller in CRCS. The proposed real time monitoring system can be utilized to adapt CRCS to real plant at initial step for commercial use. Through the this system, we are assured that CRCS is more easily fitted to real plant.

• East Asian mathematical journal
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• 제35권3호
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• pp.341-349
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• 2019

In this paper, we are concerned with the minimal positive solution to system of the nonlinear matrix equations $A_1X^2+B_1Y +C_1=0$ and $A_2Y^2+B_2X+C_2=0$, where $A_i$ is a positive matrix or a nonnegative irreducible matrix, $C_i$ is a nonnegative matrix and $-B_i$ is a nonsingular M-matrix for i = 1, 2. We apply Newton's method to system and present a modified Newton's iteration which is validated to be efficient in the numerical experiments. We prove that the sequences generated by the modified Newton's iteration converge to the minimal positive solution to system of nonlinear matrix equations.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.115-118
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• 2004

We have examined the feasibility of using the specific interaction between mistletoe lectin I (ML I) and ${\beta}$-Dgalactose instead of the anti-ML I antibody in developing a homogeneous type competitive binding assay for ML I. We also have examined the feasibility of adapting the biotin/avidin mediated homogeneous assay for this system. Alkaline phosphatase (AKP) was employed as a single substrate enzyme label. The dose-response curve shows a detection range of 1-25 ${\mu}$g/mL and a linear response with a correlation coefficient of 0.99. To demonstrate the analytical utility of this method, 10 ${\mu}$g/mL of ML I was spiked into distilled water. The results show that the mean recovery was 10.03 ${\mu}$g/mL with an SD of 0.18. The difference between the spiked value and the mean recovery was 0.03 ${\mu}$g/mL, with a relative error of 0.3 and 1.6 % of RSD.

• Journal of Biosystems Engineering
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• 제15권1호
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• pp.14-22
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• 1990

For efficient use of solar energy in plastic greenhouse, thermal storage system was developed. The system was constructed with the counter-flow type air-water heat exchanger using a thin polyethylene film as a medium of heat exchange parts. Experiments were carried out to investigate the heat exchange rate, optimum water flow rate, overall heat transfer coefficient, and the effectiveness of the counter-flow type air-water heat exchanger with polyethylene film bags. Mathematical model to predict air temperature leaving heat exchanger was developed. The results obtained in the present study are summarized as follows. 1. Heat exchange rate in the counter-flow type air-water heat exchanger with polyethylene film bags was compared to that of polyethylene film. Heat exchange rate was almost identical at air velocity of 0.5m/s on polyethylene film surface. But, heat exchange rate of heat exchanger with polyethylene film bag was $32{\sim}55KJ/m^2$ hr higher than that of polyethylene film at air velocity of 1.0m/s. 2. Considering the formation of uniform water film and the sufficient heat exchange rate of polyethylene film bags, optimum water flow rate in polyethylene film bags was $3.0{\sim}6.0{\ell}/m^2$ min. 3. The overall heat transfer coefficient of polyethylene film bags was found to be $35.0{\sim}130.0KJ/m^2\;hr\;^{\circ}C$ corresponding to the air velocity ranging 0.5 to 4.0 m/s on polyethylene film surface. And the overall heat transfer coefficient showed almost linearly increasing tendency to the variation of air velocity. 4. Mathematical model to predict air temperature leaving the heat exchanger was developed, resulting in a good agreement between the experimental and predicted values. But, the experimental results were a little lower than predicted. 5. Effectiveness of heat exchanger for the experiment was found to be 0.40~0.81 corresponding to the number of transfer units due to the variation of air velocity ranging 0.6 to 1.7 m/s.

• 대한전기학회논문지
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• 제38권6호
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• pp.393-400
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• 1989

The design criteria of Linear Induction Motors (LIM) for Auto-Conveyor System are proposed by analyzing of starting characteristics using an equivalent circuit. By contrasting the solution of the equivalent circuit with that of Maxwell's equation, we induced the parameters of the circuit. Also, the utility of the design criteria has been shown by comparing the basic characteristics with experimental values.

• Journal of Chest Surgery
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• 제31권9호
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• pp.845-854
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• 1998

Background: S-2-(3 aminoprophlamino) ethylphosphorothioic acid(WR-2721) is one of the radical scavenging thiols. We tested its protective effects in the reperfused heart. Material and Method: The experimental setup was the constant pressure Langendorffs perfusion system. We investigated the radical scavenging properties of this compound in isolated rat hearts which were exposed to 20 minutes ischemia and 20 minutes reperfusion. Four experimental groups were used:group I, control, Amifostine 50 mg(1 mL) peritoneal injection 30 minutes before ischemia(group II), Amifostine 10 mg(0.2 mL) injection during ischemia through coronary artery(group III),and Amifostine 50 mg(1 mL) peritoneal injection 2 hrs before ischemia(group IV). The experimental parameters were the levels of latate, CK-MB, and adenosine deaminase(ADA) in frozen myocardium, the quantity of coronary flow,and left ventricular developed pressure, and it's dp/dt. Statistical analysis was performed using repeated measured analysis of variance and student t-test. Result: The coronary flow of group II and IV were less than group I and III at equilibrium state but recovery of coronary flow at reperfusion state of group II, III, and IV were more increased compared with group I. The change of systolic left ventricular devoloping pressure of group II and IV were less than control group at equilibrium state, which seemed to be the influence of the pharmacological hypotensive effect of amifostine. But it was higher compared with group I at reperfusion state. The lactic acid contents of group II were less than control group in frozen myocardium.(Group I was 0.20 0.29 mM/g vs Group II, which was 0.10 0.11 mM/g). The quantity of CK-MB in myocardial tissue was highest in group IV (P=0.026 I: 120.0 97.8 U/L vs IV: 242.2 79.15 U/L). The adenosine deaminase contents in the coronary flow and frozen myocardium were not significantly different among each group. Conclusion: Amifostine seemed to have significant cardioprotective effect during ischemia and reperfusion injuries of myocardium.

• East Asian mathematical journal
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• 제28권2호
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• pp.159-172
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• 2012

In all Mathematics I Textbooks(Kim, S. H., 2010; Kim, H. K., 2010; Yang, S. K., 2010; Woo, M. H., 2010; Woo, J. H., 2010; You, H. C., 2010; Youn, J. H., 2010; Lee, K. S., 2010; Lee, D. W., 2010; Lee, M. K., 2010; Lee, J. Y., 2010; Jung, S. K., 2010; Choi, Y. J., 2010; Huang, S. K., 2010; Huang, S. W., 2010) in high schools in Korea these days, it is written and taught that for a positive real number $a$, $a^{\frac{m}{n}}$ is defined as $a^{\frac{m}{n}}={^n}\sqrt{a^m}$, where $m{\in}\mathbb{Z}$ and $n{\in}\mathbb{N}$ have common prime factors. For that situation, the author shows his opinion that the definition is not well-defined and $a^{\frac{m}{n}}$ must be defined as $a^{\frac{m}{n}}=({^n}\sqrt{a})^m$, whenever $^n\sqrt{a}$ is defined, based on the field axiom of the real number system including rational number system and natural number system. And he shows that the following laws of exponents for reals: $$\{a^{r+s}=a^r{\cdot}a^s\\(a^r)^s=a^{rs}\\(ab)^r=a^rb^r$$ for $a$, $b$>0 and $s{\in}\mathbb{R}$ hold by the completeness axiom of the real number system and the laws of exponents for natural numbers, integers, rational numbers and real numbers are logically equivalent.

• 한국정보통신학회논문지
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• 제15권8호
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• pp.1797-1804
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• 2011

본 논문에서는 주변 환경에 따라 다양한 채널 상태를 나타낼 수 있는 분산형 나카가미 페이딩 채널하에서 선형의 시공간 블록코드 (Space-Time Block Code) 직교 설계로부터 평균 비트 에러율(Bit Error Rate)성능을 평가하여 MIMO(Multiple Input Multiple Output) 채널의 안테나 열 구성과 동작환경의 영향을 분석하였고 향상된 BER을 위한 MT 안테나의 설계조건과 페이딩 지수 m을 제안 한다. 시스템 성능의 분석을 위해 M-PSK(M-ary Phase Shift Keying)변조 방식과, M-QAM(M-ary Quadra -ture Amplitude Modulation)변조 방식을 사용 하였고, 분석 식은 각각 적분된 나카가미 페이딩 변수와 적분되지 않은 나카가미 페이딩 변수로부터 시스템의 성능을 비교 분석하였다. 채널 배열의 구성은 행렬의 수식적 계산에 의해 얻게 되며, AOA 확산이 감소하는 것에 따라 STBC(Space - Time Block Codes) BER성능이 감소하며, 이와 같은 손실은 안테나 간격의 증가나, 배열구성의 변경을 통해 보상 될 수 있다.

• Plant Biotechnology Reports
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• 제5권4호
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• pp.353-365
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• 2011

The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal (MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the $H_2O_2$ and lipid peroxidation levels. Exogenous NO pretreatment of the seedlings had little influence on the nonenzymatic and enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.207-214
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• 2003

This study was carried out to establish a novel bioassay system for screening of compounds affecting aromatic amino acid or anthocyanin biosynthesis through investigating a degree of sucrose-induced anthocyanin formation such as size of plant material, buffer conditions, light intensity and irradiated duration, incubation temp., etc were determined and standard procedure (suitable experimental condition) was set up as follows. The second leaf blade of white corn seeding induced by fluridone treatment were segmented into a size of 5${\times}$5 min. The segments were floated on the solution of 1% sucrose in 1.0mM MES buffer (pH6.0∼6.5) and incubated at 26$^{\circ}C$ for 2days under the continuous light condition(70∼100$\mu$mol m$^{-2}$ s$^{-1}$ ). Anthocyanin in the purpled tissues was extracted with methanol containing 1% HCl and the optical density of the clear supematants was determined at 528mm. Influences of some chemicals were tested using this system. Glyphosate, 5-enolpyruvylshikimate 3-phosphate synthase inhibitor, showed most sensitive response with I$_{50}$ value at 3.3$\mu$M. Dicyclohexylcarbodiimide(DCCD) and parachloromercuribenzenesulfonic acid(PCMBS) had a relatively strong ingibition with I50 value at 7.1$\mu$M and 10.2$\mu$M, respectively. These results show that sucrose-induced anthocyanin formation in white com leaf segment provide a very simple and rapid system for searching new compounds affecting aromatic amino acid or anteocyanin biosynthesis by screening at less than 10$\mu$M.