• 전자공학회논문지A
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• 제32A권4호
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• pp.24-31
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• 1995

In this paper, the dual-mode burst-error-correcting decoding algorithm is adapted to the multiple trellis-coded .pi./4 shift QPSK in order to achieve the improvement of bit error rate (BER) performance over fading channels. The dual-mode adaptive decoder which combines maximum likelihood decoding with a burst detection scheme usually operates as a Viterbi decoder and switches to time diversity error recovery whenever an uncorrectable error pattern is identified. Rayleigh fading channels and Rician fading channels having the Rician parameter K=5dB are used in computer simulation, and the simulation results are compared with those of interleaving techniques. It is shown that under the constraint of the fixed overall memory quantity, the dual-mode adaptive decoding scheme gains an advantage in the BER performance with respect to interleaving strategies.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.398-403
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• 1998

This paper describes a controller design for the stator reactive power generator in the transmission system. The controller of static reactive power generator was designed using a mathematical model and non-linear state feedback. The performance of controller was verified using computer simulation with EMTP code and experimental work with scaled-model. The dynamic interaction with a simple power system was also analyzed using both the simulation model and hardware scaled-model. Both simulation and experimental results prove that the controller using PI block and non-linear state feedback offers better performance than the controller using PI block only.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제1권1호
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• pp.1-6
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• 1994

In this paper, some properties for a PI-ring satisfying the descending chain condition on essential left ideals are studied: Let R be a ring with a polynomial identity satisfying the descending chain condition on essential ideals. Then all minimal prime ideals in R are maximal ideals. Moreover, if R has only finitely many minimal prime ideals, then R is left and right Artinian. Consequently, if every primeideal of R is finitely generated as a left ideal, then R is left and right Artinian. A finitely generated PI-algebra over a commutative Noetherian ring satisfying the descending chain condition on essential left ideals is a finite module over its center.(omitted)

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1944-1946
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• 1998

This paper presents a novel current control system to eliminate the steady state control error for PWM AC-DC converter. A general mathematical model of the converter which is represented as a state-space model is established. The state-space model is used for the simulation of converter with the proposed tracking control system of sinusoidal current. In this system, a novel current control which do not require coordinate transformations using internal principle of PI controller is described. It is proved that the steady state deviation reduce to zero through a transfer function of source current control system. Finally, simulations show good source current control characteristics by means of a simplified control system which do not require coordinate transformations.

• Molecules and Cells
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• 제25권3호
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• pp.397-406
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• 2008

Computational modeling of signal transduction is currently attracting much attention as it can promote the understanding of complex signal transduction mechanisms. Although several mathematical models have been used to examine signaling pathways, little attention has been given to crosstalk mechanisms. In this study, an attempt was made to develop a computational model for the pathways involving growth-factor-mediated mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3'-kinase/protein kinase B (PI3K/Akt). In addition, the dynamics of the protein activities were analyzed based on a set of kinetic data. The simulation approach integrates the information on several levels and predicts systems behavior. The in-silico analysis conducted revealed that the Raf and Akt pathways act independently.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제5권1호
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• pp.1-3
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• 1998

Let f : X longrightarrow Y be quasi-open. We show that: (1) If A $\subset$ X is open, f│A is quasi-open, (2) f : X longrightarrow f(X) is quasi-open. (3) And let $f_{\alpha}/,:X_{\alpha}$, longrightarrow $Y_{\alpha}$ be quasi-open. Then $\Pi f_{\alpha}, : \Pi X_{\alpha}$ longrightarrow $\Pi Y_{\alpha}$/ defined by {$x_{\alpha}$} longrightarrow {$f_{\alpha},({\chi}_{\alpha}$)}, is quasi-open. (4) Lastly, if $f_{i}: X_{i}$ longrightarrow Y are quasi-open, i = 1,2, then F: $X_1 \bigoplus X_2$ longrightarrow Y, defined by $F({\chi})=f_i({\chi})$, ${\chi} \in X_i$, is also quasi-open.

• Journal of the Optical Society of Korea
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• 제18권3호
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• pp.288-291
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• 2014

This paper presents a new method for measuring the half-wave voltage $V_{\pi}$ of an electro-optic phase modulator based on a phase-modulated photonic link with interferometric demodulation. By using this method, the $V_{\pi}$ can be obtained with the RF voltage amplitude input required to achieve 1-dB gain compression of link and the differential delay of a Mach-Zehnder interferometer. We measure the $V_{\pi}$ of a commercial phase modulator by using the presented method and the carrier/the first sideband intensity ratio method. Furthermore, we compare the two measurements with the typical value provided by the manufacturer. The experiment shows that this novel measurement method is feasible, straightforward, and accurate.

• 대한수학회보
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• 제24권1호
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• pp.13-17
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• 1987

Let S denote the class of nivalent functions normalized so that f(0)=f'(0)-1=0 in vertical bar z vertical bar <1. Let $S_{\alpha}$$^{*}$, -.pi./2<.alpha.<.pi./2, denote the subclass of S that satisfies Re $e^{i{\alpha}}$zf'(z)/f(z).geq.0 in vertical bar z vertical bar <1; then f is called .alpha.-spiral-like and the case .alpha.=0 is the class of normalized starlike functions [6, pp.52]. Let T denote the class of functions f normalized as above and satisfying Im z[Im f(z)]..geq.0 in vertical bar z vertical bar <1; then f is called typically real and T contains those functions of S whose coefficients are real [6, pp.55]. Also, in view of [6, pp.231], let B(.lambda.) be the class of function normalized as above and map vertical bar z vertical bar <1 onto the complement of an arc with radial angle .lambda.(0<.lambda.<.pi./2). The radial angle is meant to be the angle between the tangent and radial vectors to the arc. This note includes a sharp version for Corollary 1 of [2] when f.mem. $S_{\alpha}$$^{*}$ as well as a logarithmic coefficient estimate.nt estimate.

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.731-738
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• 2016

Glucagon-like peptide-2 (GLP-2) is important for intestinal barrier function and regulation of tight junction (TJ) proteins, but the intracellular mechanisms of action remain undefined. The purpose of this research was to determine the protective effect of GLP-2 mediated TJ and transepithelial electrical resistance (TER) in lipopolysaccharide (LPS) stressed IPEC-J2 cells and to test the hypothesis that GLP-2 regulate TJ and TER through the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway in IPEC-J2 cells. Wortmannin and LY294002 are specific inhibitors of PI3K. The results showed that $100{\mu}g/mL$ LPS stress decreased TER and TJ proteins occludin, claudin-1 and zonula occludens protein 1 (ZO-1) mRNA, proteins expressions (p<0.01) respectively. GLP-2 (100 nmol/L) promote TER and TJ proteins occludin, claudin-1, and zo-1 mRNA, proteins expressions in LPS stressed and normal IPEC-J2 cells (p<0.01) respectively. In normal cells, both wortmannin and LY294002, PI3K inhibitors, prevented the mRNA and protein expressions of Akt and mTOR increase induced by GLP-2 (p<0.01) following with the significant decreasing of occludin, claudin-1, ZO-1 mRNA and proteins expressions and TER (p<0.01). In conclusion, these results indicated that GLP-2 can promote TJ's expression and TER in LPS stressed and normal IPEC-J2 cells and GLP-2 could regulate TJ and TER through the PI3K/Akt/mTOR pathway.

• 전자공학회논문지
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• 제51권10호
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• pp.87-95
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• 2014

본 논문에서는 이중 채널 CIS(CMOS Image Sensor) 인터페이스를 위한 수신기 설계에 대해서 기술한다. 두 채널은 각각 CTLE(Continuous-Time Linear Equalizer)를 포함하며 샘플러, 병렬 변환기 그리고 clocking 회로로 구성되어 있다. Clocking 회로는 PLL, PI, CDR을 포함한다. CDR은 PI 기반이며 OSPD(Over Sampling Phase Detector)와 FSM(Finite State Machine)을 추가하여 빠른 락 소요 시간과 지연 시간, 향상된 jitter tolerance를 갖도록 하였다. CTLE는 3 GHz에서 -6 dB 손실을 갖는 채널의 ISI(Inter Symbol Interference)를 제거하며 CDR은 8000 ppm 이하의 주파수 오프셋에 대해 1 baud period 이내의 빠른 락 소요 시간을 갖는다. 65 nm CMOS 공정을 이용하여 설계하였으며 eye diagram에서 최소 368 mV의 전압 마진과 0.93 UI의 시간 마진을 갖는다.