• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.955-959
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• 2003

A technique for realizing linear phase IIR filters has been proposed by Powell-Chau which gives a real-time implementation of H(z-1).H(z), where H(z) is a causal nonlinear phase IIR filter. Powell-Chau system is linear but not timeinvariant system. Therefore, that system has group delay response that exhibits a minor sinusoidal variation superimposed on a constant value. In the signal processing, this oscillation seriously degrade the signal quality. Unfortunately, that system has a large sample delay of 4L and also more computational complexity. Proposed system is present a reduced computational complexity technique by moved the numerator polynomial of H(1/z) out to cascade with causal filter H(z) and remain only all-pole of H(1/z), then applied truncated infinite impulse response to finite with truncated IIR filtel $H_L$(z) and L sample delay to subtract the output sequence from the top and bottom filter. Proposed system is linear time invariance and group delay response and total harmonic distortion are also improved.

• Journal of Astronomy and Space Sciences
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• 제14권2호
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• pp.347-354
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• 1997

GPS(Global Positioning System) 위성에서 수신된 L1(1575.42MHz) 반송파 위상자료를 이용하여 지표면의 두 지점의 기선 백터와 기선거리를 계산할 수 있는 S/W는 크게 네 부분으로 구성된다. 첫째는 위성의 위치를 계산하는 부분, 둘째는 단일 차분 방정식을 구성하는 부분 셋째는 이중 차분을 구성하는 부분, 그리고 마지막으로 상관관계를 계산하는 부분이다. 개발한 S/W의 정확도를 검증하기 위하여, 대전 천문대의 GPS 관측소($N37^{circ}.75,E127^{circ}.37,H77.61m$)를 중심으로 약 2.7, 42.1, 81.1, 146.6km 떨어진 네 지점에서 Trimble 수신기를 이용하여 동시에 GPS 위성으로부터 관측자료를 획득하였다. 획득한 관측자료를 이 연구에서 개발한 S/W로 처리하였고, 그 결과를 Trimble사의 자료처리 S/W인 GPS Survey에 GPS 위성의 방송 궤도력을 적용하여 L1/L2 ION-Free 기법으로 계산한 결과와 비교 하였다. 두 S/W 시스템으로 산출한 기선 백터의 각 성분은 약 50cm내외에서 잘 일치하였고 기선 거리는 약 10cm내외에서 서로 일치하였다.

• 분석과학
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• 제20권1호
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• pp.70-77
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• 2007

클로로페놀 12종을 폐수로부터 LPME법을 사용하여 추출하였고, GC/MS로 분석하였다. 최적의 추출조건을 확립하기 위해 추출용매의 종류, 시료의 양, pH, 염석 효과, 플런저 왕복 횟수 및 속도를 고려하여 최적의 조건을 확립하였다. 그 결과, 직선성이 0.9913에서 0.9999를 가지는 12가지의 검정곡선을 얻을 수 있었고, 검출한계와 정량한계도 2,3,4,5-테트라클로로페놀과 펜타클로로페놀(0.05-500 ng/mL)을 제외하고 0.05~10.0 ng/mL범위에서 얻을 수 있었다. 실제 폐수에서 4-클로로-3-메틸페놀(784 ng/mL)을 확인할 수 있었다.

• Journal of Animal Science and Technology
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• 제56권6호
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• pp.22.1-22.7
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• 2014

The present study was performed to investigate the effects of two groups of sires with 'medium' and 'high' weight gain potentials (M-sires and H-sires, respectively) on growth of their progenies on varying planes of nutrition during the growing-finishing period. The ADG of the M-sires' progeny was greater (P < 0.05) than that of the H-sires' progeny (0.51 vs. 0.47 kg) during a 26- to 29-d early grower phase beginning from 55 d of age, but the opposite was true (0.66 vs. 0.72 kg) during the latter grower phase. Overall grower-phase ADG was greatest on the high plane of nutrition (H plane) followed by the medium (M) and low (L) planes (0.65, 0.61, and 0.51 kg, respectively; P < 0.05) in the M-sires' progeny, whereas in the H-sires' progeny, ADG was greater on the H and M planes vs. L plane (0.63, 0.62, and 0.54 kg, respectively). The ADG of pigs on the M or H plane during the grower phase and switched to the H plane thereafter (M-to-H or H-to-H planes) was greater than that of pigs on the L-to-L planes (0.99 vs. 0.78 kg) during the early finisher phase in the M-sires' progeny (P < 0.01). However, in the H-sires' progeny, ADG of pigs on the L-to-L planes did not differ from that of pigs on the M-to-M or H-to-M planes (0.94 vs. 0.96 kg). Results suggest that the H-to-H or H-to-M planes and M-to-M or M-to-L planes are optimal for maximal growth of the M- and H-sires' progenies, respectively.

• Archives of Pharmacal Research
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• 제29권4호
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• pp.339-342
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• 2006

A simple high performance liquid chromatographic (HPLC) method was developed for the determination of tolperisone in human plasma. Tolperisone and internal standard (chlorphenesin) were isolated from 1 mL of plasma using 8 mL of dichlormethane. The organic phase was collected and evaporated under nitrogen gas. The residue was then reconstituted with 300 mL aliquot of mobile phase and a 100 mL aliquot was injected onto the $C_{18}$ reverse-phased column. The mobile phase, $45\%$ methanol containing $1\%$ glacial acetic acid and $0.05\%$ 1-hexanesulfonic acid was run at a flow rate of 1 mL/min. The column effluent was monitored using UV detector at 260 nm. The retention times for tolperisone and the internal standard were approximately 7.1 and 8.4 min, respectively. The standard curve was linear with minimal intra-day and inter-day variability. The quantification limit of tolperisone in human plasma was 10 ng/ mL. The proposed method has been applied to the determination of pharmacokinetic profile of tolperisone in Koreans. The T max of tolperisone in Koreans $(0.94{\pm}0.42\;h)$ was not significantly differ from that reported in Europeans (0.5-1 h), but the mean half-life in Koreans $(1.14{\pm}0.27\;h)$ was shorter than that in Europeans $(2.56{\pm}0.2\;h)$. The proposed HPLC method is simple, accurate, reproducible and suitable for pharmacokinetic study of tolperisone.

• 대한화학회지
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• 제58권6호
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• pp.535-542
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• 2014

간편하고 효율적이며 친환경적인 시료전처리 방법인 3-상 속빈 섬유 액체상 미량추출법(3-phase HF-LPME) 및 HPLC-UV/Vis를 이용하여 소변 중에 존재하는 테트라사이클린류 항생제 3종(tetracycline, oxytetracycline, chlortetracycline)을 동시에 분석하는 방법을 개발하였다. 분석 물질은 $C_8$ 컬럼($150{\times}3.0mm$, $3{\mu}m$)을 사용하여 기울기 용리법으로 분리되었으며 높은 선택성과 감도를 나타내었다. 시료 전처리를 위한 최적의 실험조건을 확립하였는데, 추출용매로는 heptanal, 추출시간은 60분, 주개 상의 pH는 9.0, 받개 상의 pH는 1.0, 시료의 교반속도는 700 rpm, 추출 시간은 60분이었으며 농축인자는 5.6~22.3이었다. 검출한계와 정량한계는 각각 $0.08{\sim}0.8{\mu}g/mL$와 $0.4{\sim}1.6{\mu}g/mL$이었으며, $0.1{\sim}32{\mu}g/mL$ 농도범위의 검정곡선은 좋은 직선성($R^2$ >0.995)과 정밀도(1.3~9.1 RSD %) 및 정확도(84~118%)를 나타냈다.

• 한국해양학회지:바다
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• 제19권2호
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• pp.125-130
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• 2014

해저 하구의 자하수 중 콜로이드 상 $^{210}Pb$ (반감기: 22.2년)과 $^{210}Po$ (반감기: 138일)의 분포 특성을 알아내기 위해서, 용존 상(<10 kDa)과 콜로이드 상($10kDa-0.45{\mu}m$)의 $^{210}Pb$과 $^{210}Po$ 시료를 채취하여 측정하였다. 함평만(2010년 7월)과 제주도(2011년 1월)의 연안 지하수 중 용존 상 $^{210}Pb$의 농도는 $0.21-2.52mBqL^{-1}$ 범위를 보였고, 콜로이드 상에서는 $0.10-1.71mBqL^{-1}$ 범위를 보였다. 용존 상 $^{210}Po$의 농도는 $0.12-2.07mBqL^{-1}$ 범위를 보였고, 콜로이드 상에서는 $0.03-0.97mBqL^{-1}$ 범위를 보였다. 총 용존 상에서 콜로이드 상 $^{210}Pb$과 $^{210}Po$의 비율은 각각 $40{\pm}5%$와 $28{\pm}5%$를 차지하였다. 이 결과는 해저를 통한 미량 원소의 해양 유출에 콜로이드가 중요한 역할을 한다는 것을 나타낸다.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.12-15
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• 2011

The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to be reinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in waste water. Liquid-liquid extraction (LLE) is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes it inadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE) method for the analysis of dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompression pump, which enables continuous semi-automated extraction. Small (0.5 L) and large (7 L) samples were extracted using LLE and SPE methods, respectively. The method detection limits (MDLs) were 0.001.0.25 and 0.015.4.1 pg I-TEQ/L for the SPE and LLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrations of several congeners that were not detected with the LLE method were quantified using the SPE method.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.233-240
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• 2024

The wall friction correlations of oscillatory natural circulation loops are highly loop-specific, making it difficult to perform 1-D system simulations before obtaining specific experimental data. To better predict the friction characteristics, the nonlinear dynamics of a toroidal single-phase natural circulation loop were numerically investigated, and the transition effect was considered. The k-k_L-ω transitional turbulence and k-ω SST turbulence models were used to compute the flow characteristics of the loop under different heating powers varying from 0.48 to 1.0 W/cm², and the results of both models were compared with previous experiments. The mass flow rates and friction factors predicted by the k-k_L-ω model showed a better agreement with the experimental data than the results of the k-ω SST model. The oscillation frequencies calculated using both models agreed well with the experimental data. The k-k_L-ω transitional turbulence model provided better friction-factor predictions in oscillatory natural circulation loops because it can reproduce the temporal and spatial variation of the wall shear stress more accurately by capturing the movement of laminar, transition turbulent zones inside unstable natural circulation loops. This study shows that transition effects are a possible explanation for the highly loop-specific friction correlations observed in various oscillatory natural circulation loops.

• 한국산학기술학회논문지
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• 제6권1호
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• pp.12-16
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• 2005

EFM(electrostatic force microscopy)을 이용하여 탄소나노튜브를 측정하였다. EFM 위상 이미지론 얻었을 때, 위상차(${\Delta}{\phi}^{-l/2}$)와 탄소나노튜브 길이(L)의 역수는 선형관계를 보였다. 또한 위상차는 캔틸레버 팁과 탄소나노튜브 사이의 거리(h)의 제곱에 반비례하였다.