• Journal of Applied Biological Chemistry
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• 제43권3호
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• pp.170-175
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• 2000

A pot-lysimeter experiment was conducted with 3-year-old 'Tsugaru' apple (Malus domestica Borkh) trees to examine the changes in oxygen diffusion rate (ODR) with lateral flow velocity of water through soil. The influence of lateral water flow velocity on water relations and elemental content in leaf, and sap temperature distribution patterns of the xylem of trees were also determined. Trees were grown under four soil water regimes: (1) fast laterally flowing (FWT, $2.50{\times}10^{-4}cm\;s^{-1}$), (2) slow laterally flowing (SWT, $0.25{\times}10^{-4}cm\;s^{-1}$), and (3) stagnant water table (WLT) at 60-cm, and (4) drip-irrigation at -40 kPa of soil matric potential as a control. The rate of $O_2$ diffusion converged near $2{\times}10^{-3}g\;m^{-2}\;min^{-1}$ for FWT and control soils, but decreased below $1{\times}10^{-3}g\;m^{-2}\;min^{-1}$ 40 days after treatment (DAT) for WLT soils. For SWT soils, however, the ODR at 15 cm below the soil surface was similar to that of control, but at 45 cm below the soil surface, ODR was similar to that of the WLT treatment. Leaf water potential of FWT and SWT plants was similar to that of control plants, but the values for SWT plants declined by 98 DAT. Leaf water potential of WLT plants decreased from -1.86 MPa (9 DAT) to -2.41 MPa (59 DAT) and finally down to -2.70 MPa. The sap temperature measured at 1100-hr was lowest at top and highest at bottom for FWT and control plants, but this pattern of SWT and WLT plants was disturbed from 29 DAT. However, for SWT plants, such thermal disturbance of sap temperature disappeared from 63 DAT.

• 약학회지
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• 제28권4호
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• pp.207-215
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• 1984

Effects of Ssang Wha Tang (SWT), a blended Chinease traditional medicine, on the pharmacokinetics of sulfobromophthalein (BSP) in the rats of hepatic failure induced by carbon tetrachloride were examined. The disposition of plasma BSP in carbon tetrachloride-treated rats (Group I) and in carbon tetrachloride+SWT-treated rats (Group II) followed a three-compartment model, while those in control group followed two-compartment model. GOT, GPT level and some pharmacokinetic paramiters like plasma clearance but except distribution volume (Vdss) recovered in Group II compared to Group I. Therefore, SWT seemed to have an apparent restoring effect of hepatic function damaged by carbon tetrachloride treatment. From the fact that Vdss of BSP in Group II was considered as an one of the probable mechanisms. More intensive increase in BSP-free fraction ($f_p$) in Group II than that in Group I might also explain the increases of BSP clearance and Vdss in Group II compared to Group I. Assuming no changes in hepatic plasma flow(Q) in each group, hepatic intrinsic clearance($CL^h_{int}$) decreased in Group I did not recovered not at all in Group II. Therefore SWT seemed not to have any restoring effect of true hepaticfunction to biotransform and excrete BSP, and the apparent restoring effect of SWT might be due only to the replacement of BSP-plasma protein binding. Whether $f_p$ is actually higer in Group II than in Group I, and Q is constant in each group are being examined in our laboratory. The changes of Q, which might lead to another conculusions, also should be taken into consideration to clarify the apparent hepatorestoring effect of SWT.

• 한국해안·해양공학회논문집
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• 제22권5호
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• pp.316-325
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• 2010

황해중부해역에 설치된 황해 모니터링 부이에서 관측한 기온과 표층수온의 변동성분을 추출하기 위하여 조화분석을 수행하였다. 분석결과, 기온과 표층 수온 모두 1년, 반년 주기성분이 가장 우세한 것으로 파악되었으며, 보다 짧은 주기성분은 $0.2{\sim}0.5^{\circ}C$ 이하의 작은 변동성분에만 기여하는 것으로 파악되었다. 한편, 기온과 표층수온의 조화분석 성분에서 추출한 잔차성분을 분석한 결과, 기온 잔차성분의 표준편차는 표층 수온 잔차성분의 표준편차보다 2.4배 정도 크고, 잔차성분의 발생빈도분포는 정규분포로 근사화하는 것이 가능한 것으로 파악되었다. 한편, 기온에 따른 표층수온 변화양상을 기온-표층수온 평면에서 분석한 결과 뚜렷한 연속적인 이력고리(hysteresis loop)를 형성하는 것이 발견되었으며, 반시계방향의 기온-표층수온 상승기, 기온-표층수온 하강기 그리고 동계 일정한 표층수온 유지기로 구성되어 있는 것으로 파악되었다.

• 한국물환경학회지
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• 제23권3호
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• pp.324-331
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• 2007

This study was conducted to evaluate the influence of pollutant loads on the water quality in the Goseong reservoir from May 2005 to October 2006. Annual total runoff at the Goseong-cheon watershed was 968.0 mm in 2005, 382.6 mm in 2006, respectively. The mean concentration of BOD, COD and SS in the stream were 2.28, 6.03, 46.97 mg/L in rainy seasons and 0.95, 2.14, 6.05 mg/L in dry seasons at SWT C sub-watershed. Total-N concentrations ranged from 2.60 to 3.18 mg/L at SWT C sub-watershed, which was generally higher than the quality standard of agricultural water (1.0 mg/L). Total-P concentrations ranged from 0.044 to 0.130 mg/L at SWT C sub-watershed. Measured pollutant loads in the SWT C sub-watershed were 36.7 kg/day of BOD, 72.3 kg/day of T-N and 2.3 kg/day of T-P in 2005 at SWT C sub-watershed, 63.9 kg/day of BOD, 82.8 kg/day of T-N and 1.1 kg/day of T-P in 2006 at SWT C sub-watershed, respectively. In the analysis of the effluent characteristics for NPS pollutants, it appeared that the loading rates of effluent from SWT C watershed were, respectively, BOD 62.3%, T-N 69.6%, T-P 71.1%, SS 70.1% during the rainy season in 2006. The calculated T-N daily pollutant loadings by the unit loading factor method from each sub-watershed were much greater than observed, but the calculated T-P daily pollutant loadings much lesser than observed.

• 한국안전학회지
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• 제29권3호
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• pp.1-7
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• 2014

In this study, for the evaluation of the static and fatigue joining strength of the joint, the geometry of the cross-tension specimen was adopted. The specimens were produced with optimal joining force and fatigue life of the clinch joint specimens was evaluated. The material selected for use in this study was cold rolled mild steel (SPCC) with a thickness of 0.8 mm. The maximum tensile load was 708 N for the specimen with single point. The fatigue endurance limit (=42.6 N) per point approached to 6% of the maximum tensile strength at a load ratio of 0.1, suggesting that the joints are vulnerable to cross-tension loading during fatigue. Compared to equivalent stress and maximum principal stress, the SWT fatigue parameter and equivalent strain can properly predict the current experimental fatigue life. The SWT parameter can be expressed as $SWT=2497.5N^{-0.552)_f$.

• 스마트미디어저널
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• 제6권4호
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• pp.32-40
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• 2017

In this paper, a robust text detection method based on edge enhanced contrasting extremal region (CER) is proposed using stroke width transform (SWT) and tensor voting. First, the edge enhanced CER extracts a number of covariant regions, which is a stable connected component from input images. Next, SWT is created by the distance map, which is used to eliminate non-text regions. Then, these candidate text regions are verified based on tensor voting, which uses the input center point in the previous step to compute curve salience values. Finally, the connected component grouping is applied to a cluster closed to characters. The proposed method is evaluated with the ICDAR2003 and ICDAR2013 text detection competition datasets and the experiment results show high accuracy compared to previous methods.

• 한국지구과학회:학술대회논문집
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• 한국지구과학회 2005년도 추계학술발표회 논문집
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• pp.400-407
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• 2005

웨이브렛 변환(Wavelet Transform)은 시간영역과 주파수영역에서 동시에 분석이 가능하고 불연속적인 자료를 분석하는데 유리하기 때문에 그동안 영상을 처리하고 분석하는데 널리 이용되어 왔다. Discrete Wavelet Transform(DWT)는 주어진 영상에서 특성 정보는 유지하면서 다른 여러 종류의 계수로 분해 할 수 있게 해주기 때문에, 계수에 임계치를 적용해 고주파 성분을 제거하면 잡음을 줄일 수 있다. Stationary Wavelet Transform(SWT)는 DWT에서 다운샘플링에 의해 발생하는 문제점을 해결하기 위한 변환방법으로 잡음제거에 DWT보다 효과적이라고 알려져 있다. 이 연구에서는 DWT와 SWT에 의한 필터링을 광학영상과 레이더 영상에 적용하여 보고, 기존의 필터링 기법과 그 결과를 비교하였다. 그 결과 SWT에 의한 방법이 경계성분은 보존하면서 잡음을 가장 효과적으로 줄일 수 있었다.

• 한국정밀공학회지
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• 제24권4호
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• pp.123-130
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• 2007

Recently, a lot of work and interest have been devoted to the development of multiaxial fatigue parameters for fretting fatigue life prediction. In this study, the fretting fatigue lift and critical location ware estimated and evaluated through the multiaxial fatigue theories in a cylinder-on-flat contact configuration far Cr-Mo steel, SCM420, the material commonly is used in gears of the automobile and rollers of the conveyor. The strain-life curve was obtained from fatigue test for SCM420. The Fretting fatigue life and critical location were estimated through stress distributions, SWT-parameters and FS-parameters obtained from FEA. This paper showed possibility of applying multiaxial fatigue theories to fretting fatigue lift prediction comparing predicted life with experimental results.

• Smart Structures and Systems
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• 제9권5호
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• pp.441-459
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• 2012

Identification of vibration parameters from the analysis of the dynamic response of a structure plays a key role in current health monitoring systems. This study evaluates the capabilities of the recently developed Synchrosqueezed Wavelet Transform (SWT) to extract instant frequencies and damping values from the simulated noise-contaminated response of a structure. Two approaches to estimate the modal damping ratio from the results of the SWT are presented. The results obtained are compared to other signal processing methods based on Continuous Wavelet (CWT) and Hilbert-Huang (HHT) transforms. It was found that the time-frequency representation obtained via SWT is sharped than the obtained using just the CWT and it allows a more robust extraction of the individual modal responses than using the HHT. However, the identification of damping ratios is more stable when the CWT coefficients are employed.

• 인터넷정보학회논문지
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• 제25권1호
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• pp.109-121
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• 2024

섬유, 자동차와 같은 여러 제조 공정에서 설비가 고장이 나 멈추게 되면 기계가 작동하지 않게 되고 이는 기업의 시간적, 금전적 손실로 이어진다. 따라서 설비의 고장이 발생하기 전, 고장을 예측하여 정비할 수 있도록 설비의 이상을 사전에 탐지하는 것이 중요하다. 대부분의 설비 고장 원인은 설비의 필수 부품인 베어링의 고장으로, 베어링의 고장을 진단하는 것은 설비예지보전 연구의 핵심이기도 하다. 본 논문에서는 베어링의 진동 신호를 분석하여 SWT-SVD 전처리 알고리즘을 제안하고 이를 시계열 이상탐지 모델 네트워크 중 하나인 어노멀리 트랜스포머에 적용하여 베어링 이상탐지 모델을 구현한다. 제조공정의 베어링 진동신호는 실시간으로 센서값들의 이력이 작성되어 노이즈가 존재하므로, 이를 줄이기 위해 본 연구에서는 정상 웨이블릿 변환(Stationary Wavelet Transform)을 사용하여 주파수 성분을 추출하고, 특이값 분해(Singular Value Decomposition) 알고리즘을 통해 유의미한 특징들을 추출하는 전처리를 진행한다. 제안하는 SWT-SVD 전처리 방법을 적용한 베어링 이상탐지 모델 실험을 위해 IEEE PHM학회에서 제공하는 PHM-2012-Challenge 데이터 세트를 활용하였으며, 실험 결과는 0.98의 정확도와 0.97의 F1-Score로 우수한 성능을 보였다. 추가로, 성능 향상을 입증하기 위해 선행 연구들과 성능 비교를 진행한다. 비교 실험을 통해 제안한 전처리 방법이 기존의 전처리보다 높은 성능을 보임을 확인하였다.