• Journal of the Korean Society of Industry Convergence
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• v.26 no.3
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• pp.401-409
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• 2023

Oscillating water column (OWC) type wave power generator system is a power generation system that uses wave energy, a sustainable and renewable energy source. Irregular cycles and wave heights act as factors that make it difficult to secure generation efficiency of the wave power generator system. Recently, research for improving power generation efficiency is being conducted by applying digital twin technology to OWC type wave energy converter system. However, digital twin using sensor data can predict erroneous performance due to uncertainty in the sensor data. Therefore, this study proposes an uncertainty analysis method for sensor data which is used in digital twin to secure the reliability of digital twin prediction results. Uncertainty quantification considering sensor data characteristics and future uncertainty information according to uncertainty propagation were derived mathematically, and confidence interval estimation was performed based on the proposed method.

• Korean Journal of Radiology
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• v.25 no.6
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• pp.540-549
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• 2024

Objective: This study investigated the feasibility and prognostic relevance of threshold-based quantification of myocardial delayed enhancement (MDE) on CT in patients with nonischemic dilated cardiomyopathy (NIDCM). Materials and Methods: Forty-three patients with NIDCM (59.3 ± 17.1 years; 21 male) were included in the study and underwent cardiac CT and MRI. MDE was quantified manually and with a threshold-based quantification method using cutoffs of 2, 3, and 4 standard deviations (SDs) on three sets of CT images (100 kVp, 120 kVp, and 70 keV). Interobserver agreement in MDE quantification was assessed using the intraclass correlation coefficient (ICC). Agreement between CT and MRI was evaluated using the Bland-Altman method and the concordance correlation coefficient (CCC). Patients were followed up for the subsequent occurrence of the primary composite outcome, including cardiac death, heart transplantation, heart failure hospitalization, or appropriate use of an implantable cardioverter-defibrillator. The Kaplan-Meier method was used to estimate event-free survival according to MDE levels. Results: Late gadolinium enhancement (LGE) was observed in 29 patients (67%, 29/43), and the mean LGE found with the 5-SD threshold was 4.1% ± 3.6%. The 4-SD threshold on 70-keV CT showed excellent interobserver agreement (ICC = 0.810) and the highest concordance with MRI (CCC = 0.803). This method also yielded the smallest bias with the narrowest range of 95% limits of agreement compared to MRI (bias, -0.119%; 95% limits of agreement, -4.216% to 3.978%). During a median follow-up of 1625 days (interquartile range, 712-1430 days), 10 patients (23%, 10/43) experienced the primary composite outcome. Event-free survival significantly differed between risk subgroups divided by the optimal MDE cutoff of 4.3% (log-rank P = 0.005). Conclusion: The 4-SD threshold on 70-keV monochromatic CT yielded results comparable to those of MRI for quantifying MDE as a marker of myocardial fibrosis, which showed prognostic value in patients with NIDCM.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.3
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• pp.293-298
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• 2013

• Proceedings of the Korea Society of Design Studies Conference
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• 2001.10a
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• pp.10.2-10
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• 2001

• Korean Journal of Environmental Agriculture
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• v.4 no.2
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• pp.114-117
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• 1985

A new method for micro-quantification of abscisic acid from plant tissue is described. GLC-ECD method of abscisic acid pertafluorobenzyl ester synthesized by reaction of plant extract with pentafluorobenzyl bromide showed higher sensitivity than that of abscisic acid methyl ester, and the detection limit of abscisic acid by the described method was as low as 5 pg.

• YAKHAK HOEJI
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• v.59 no.1
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• pp.6-11
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• 2015

A simple HPLC-UV method was developed and validated for the quantification of human serum isepamicin using phenylisocyanate as a derivatization agent. The linear calibration curve was obtained in the concentration range of $1{\sim}100{\mu}g/ml$ and LLOQ of $1{\mu}g/ml$. This method was validated with selectivity, linearity, precision and accuracy, leading to successful application for estimating the pharmacokinetic parameters of isepamicin in Korean healthy subjects following IV infusion of 800 mg isepamicin. The mean $t_{1/2}$ of isepamicin was $1.55{\pm}0.08hr$.

• Proceedings of the KIEE Conference
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• summer
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• pp.645-647
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• 2004

According to NERC definition, Available Transfer Capability (ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity To calculate ATC, accurate and defensible TTC, CBM and TRM should be calculated in advance. This paper proposes a method to quantify time varying ATC based on probabilistic approach. The uncertainties of power system and market are considered as complex random variables. TRM with the desired probabilistic margin is calculated based on PLF analysis, and CBM is evaluated using LOLE of the system. Suggested ATC quantification method is verified using IEEE RTS with 72 bus. The proposed method shows efficiency and flexibility for the quantification of ATC.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.1-13
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• 2005

Fluid flows within microchannels are characterized by low Reynolds numbers. Therefore the effect of mixing is a crucial factor in design of the channels. Since the action of the electro-osmotic or magnetic forces used in the mixing enhancement is usually periodic in the three-dimensional channel configuration, use of the various concepts of chaotic advection is reasonable in the quantification of the stirring effect. In this paper, the details of the method of material-stretching mapping is explained. The actual application of the method to the screw extruder is also presented.

• YAKHAK HOEJI
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• v.60 no.1
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• pp.15-20
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• 2016

Globotriaosylsphingosine (lyso Gb3) is considered as one of the biomarkers for Fabry disease. A rapid and simple UPLC-MS/MS method was developed for the determination of reliable biomarker, lyso Gb3. Total analytical procedure takes only 15 min including sample preparation and MS/MS analysis. Limit of detection was 0.85 ng/ml (S/N=3). The calibration curve was linear over the range of 2.0~400.0 ng/ml ($R^2=0.9999$). Inter-day and intra-day assay accuracy were 93.4~100.6% (RSD, 0.6~6.0%) and 97.5~100.7% (RSD, 3.6~5.2%). Absolute recoveries of 97.6~98.6 showed excellence of a new analytical method. The method was applied to human and mice urines, proved the suitability for the quantification of lyso-Gb3 for screening, diagnosis and therapeutic monitoring of Fabry disease patients.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.11
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• pp.533-539
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• 2005

According to NERC definition, Available Transfer Capability (ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity. To calculate Available Transfer Capability, accurate and defensible Total Transfer Capability, Capacity Benefit Margin and Transmission Reliability Margin should be calculated in advance. This paper proposes a method to quantify time varying Available Transfer Capability based on probabilistic approach. The uncertainties of power system and market are considered as complex random variables. Total Transfer Capability is determined by optimization technique such as SQP(Sequential Quadratic Programming). Transmission Reliability Margin with the desired probabilistic margin is calculated based on Probabilistic Load Flow analysis, and Capacity Benefit Margin is evaluated using LOLE of the system. Suggested Available Transfer Capability quantification method is verified using IEEE RTS with 72 bus. The proposed method shows efficiency and flexibility for the quantification of Available Transfer Capability.