• ETRI Journal
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• 제45권5호
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• pp.874-886
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• 2023

A joint resource-optimization scheme is investigated for nonorthogonal multiple access (NOMA)-enhanced scalable video coding (SVC) multicast in unmanned aerial vehicle (UAV)-assisted radio-access networks (RANs). This scheme allows a ground base station and UAVs to simultaneously multicast successive video layers in SVC with successive interference cancellation in NOMA. A video quality-maximization problem is formulated as a mixed-integer nonlinear programming problem to determine the UAV deployment and association, RAN spectrum allocation for multicast groups, and UAV transmit power. The optimization problem is decoupled into the UAV deployment-association, spectrum-partition, and UAV transmit-power-control subproblems. A heuristic strategy is designed to determine the UAV deployment and association patterns. An upgraded knapsack algorithm is developed to solve spectrum partition, followed by fast UAV power fine-tuning to further boost the performance. The simulation results confirm that the proposed scheme improves the average peak signal-to-noise ratio, aggregate videoreception rate, and spectrum utilization over various baselines.

• 한국통신학회논문지
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• 제38A권10호
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• pp.838-844
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• 2013

본 논문에서는 통화량이 많은 상황에서 인지 무선 시스템을 위한 센싱 구간 분할 기반 스펙트럼 센싱 기법을 제안한다. 구체적으로는 센싱 구간을 K개의 구간으로 분할하고, 각 분할된 구간에 스펙트럼 센싱을 수행한 결과들로부터 최종적으로 일차 사용자 신호의 유무를 판단하는 스펙트럼 센싱 기법을 제안한다. 모의실험을 통해 제안한 기법이 통화량이 많은 상황에서 기존 기법들에 비해 더욱 우수한 스펙트럼 센싱 성능을 가짐을 확인한다.

• 약학회지
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• 제8권4호
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• pp.94-95
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• 1964

Ether extract of the fruits of Angelica gigas NAKAI(Umbelliferae) growing wild and cultivating in Korea, afforded frocoumarin derivative, imperatorin which was identified through physical constants-I.R.spectrum, paper partition chromatography, and preparation of derivatives.

• ETRI Journal
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• 제30권3호
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• pp.412-420
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• 2008

A new scan partition architecture to reduce both the average and peak power dissipation during scan testing is proposed for low-power embedded systems. In scan-based testing, due to the extremely high switching activity during the scan shift operation, the power consumption increases considerably. In addition, the reduced correlation between consecutive test patterns may increase the power consumed during the capture cycle. In the proposed architecture, only a subset of scan cells is loaded with test stimulus and captured with test responses by freezing the remaining scan cells according to the spectrum of unspecified bits in the test cubes. To optimize the proposed process, a novel graph-based heuristic to partition the scan chain into several segments and a technique to increase the number of don't cares in the given test set have been developed. Experimental results on large ISCAS89 benchmark circuits show that the proposed technique, compared to the traditional full scan scheme, can reduce both the average switching activities and the average peak switching activities by 92.37% and 41.21%, respectively.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1211-1218
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• 2018

Within the framework of the modified factorization method, we solve the $Schr{\ddot{o}}dinger$ equation with the modified Yukawa potential. The energy spectrum is obtained using the Pekeris approximation scheme for the centrifugal term. The thermodynamic properties, including the vibrational partition function, vibrational mean energy, vibrational mean free energy, vibrational specific heat capacity and vibrational entropy, are calculated. As a special case, we compare our result with that work of Dong [Int. J. Quant. Chem. 107, 366 (2007)] and find good agreement.

• 지구물리
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• 제6권1호
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• pp.25-29
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• 2003

3성분 지진기록을 주파수 영역에서 벡터적으로 합성하여 퓨리에 진폭스펙트럼 분석의 불확실성을 저감하는 방법을 제시하였다. 3성분 합성 퓨리에 진폭스펙트럼을 이용한 분석기법은 두 가지 장점이 있다. 첫째, 단일 성분에서 나타나는 벡터 분할비를 제거함으로써 지진모멘트 추정의 신뢰도를 향상시킨다. 둘째, 퓨리에 스펙트럼의 형상을 강화시킴으로써 지진모멘트, 모서리 주파수, 고주파성분 감쇠상수($χ$) 등을 정확하게 추정할 수 있다. 특히, 두 번째 장점은 신호/잡음비가 낮은 미소지진 기록의 분석에 유용하다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.103-110
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• 2005

Broken rotor bars in induction motors can be detected by monitoring any abnormality of the spectrum amplitudes at certain frequencies in the motor current spectrum. Broken rotor bar fault detection schemes should rely on multiple signatures in order to overcome or reduce the effect of any misinterpretation of the signatures that are obscured by factors such as measurement noises and different load conditions. Multiple Discriminant Analysis (MDA) and Artificial Neural Networks (ANN) provide appropriate environments to develop such fault detection schemes because of their multi-input processing capabilities. This paper describes two fault detection schemes for broken rotor bar fault detection with multiple signature processing, and demonstrates that multiple signature processing is more efficient than single signature processing.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.47-50
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• 1991

An automatized latency calculation method of evoked otoacoustic emission is proposed. Averaged e-OAE signal is measured from normal adult and it is processed by IBM-AT computer for latency calculation. After partition of stimulated and emitted signal on the time axis by converted linear prediction coding spectrum, latency is calculated by cross correlation method. The output is also compared with those of conventional autocorrelation and pure cross correlation methods. The result show that proposed method has better performance than those of conventional ones.

• 대한수학회지
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• 제42권4호
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• pp.857-869
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• 2005

Let $(X,\;B,\;{\mu},\;T)$ be a dynamical system and (Y, A, v, S) be a factor. We investigate the relative sequence entropy of a partition of X via the maximal compact extension of (Y, A, v, S). We define relative sequence entropy pairs and using them, we find the relative topological ${\mu}-Kronecker$ factor over (Y, v) which is the maximal topological factor having relative discrete spectrum over (Y, v). We also describe the topological Kronecker factor which is the maximal factor having discrete spectrum for any invariant measure.

• 약학회지
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• 제37권6호
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• pp.638-646
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• 1993

A cepfialosporin with an aminothiazoiylmethoxyimino-type side chain at the 7 position and bicyclic quinolone dithicarbamate at the 3' position was synthesized. It has broad and potent antivacterial activity in vitro. The antibacterial spectrum reflects contributions of both the cephalosporin moiety and the quinolone moiety. Thus, this compound was named DACD implying a dualaction cephalosporin derivative. In this paper, the physicochemical proper-ties (lipid-water partition, pKa), stability and pharmacokinetics of DACD were determined and compared with cefotaxime 3'-norfloxacin dithiocarbamate (CENO). Stability tests were studied in pH 1.20, 6.80 and 8.00 buffers and in the presence of AB type human plasma, rat liver homogenate and its .betha.-lactamase. The pharmacokinetic parameters of DACD were evaluated in mice after a single intravenous dose of 40 mg/kg. The results are as follows. The lipid-water partition coefficient of DACD was higher than that of CENO. The calculated pKa values of CENO and DACD, were 6.82$\pm$0.03, 7.53$\pm$0.21, respectively. In the hydrolysis test, half-lives (t$^{1/2}$) of CENO and DACD was 66.0 hr and 80.0 hr in pH 6.80 buffer, 190 hr and 91.4 hr in pH 8.00 buffer. CENO and DACD were rapidly hydrolyzed in human plasma and in rat liver hornogenate. Half-lives (t$_{1/2}$ of CENO and DACD were 1.29 hr and 1.15 hr in hyman plasma, 0.62 hr and 0.71 hr rat liver homogenate. In $\beta$-lactamase stability test, CENO and DACD were very stable to the .betha.-lactamases obtained from three different strains. Half-life (t$_{1/2}$) and areas under the curve (AUC) in mice were 2.33 hr and 15.97 (mg.h/1), respectively.