• JOURNAL OF ELECTRICAL WORLD
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• no.6 s.138
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• pp.45-53
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.8 s.140
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• pp.31-39
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.5 s.137
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• pp.43-53
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• 1988

• JOURNAL OF ELECTRICAL WORLD
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• no.4 s.136
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• pp.42-49
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• 1988

• JOURNAL OF ELECTRICAL WORLD
• /
• no.7 s.139
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• pp.51-60
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• 1988

• The Korean Journal of Nuclear Medicine
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• v.7 no.1
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• pp.1-13
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• 1973

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.252-265
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• 2021

Cardiac magnetic resonance imaging (MRI) serves as a clinical gold-standard non-invasive imaging technique for the assessment of global and regional cardiac function. Conventional cardiac MRI is limited by the long acquisition time, the need for ECG gating and/or long breathhold, and insufficient spatiotemporal resolution. Real-time cardiac cine MRI refers to high spatiotemporal cardiac imaging using data acquired continuously without synchronization or binning, and therefore of potential interest in overcoming the limitations of conventional cardiac MRI. Novel acquisition and reconstruction techniques must be employed to facilitate real-time cardiac MRI. The goal of this study is to discuss methods that have been developed for real-time cardiac MRI. In particular, we classified existing techniques into two categories based on the use of non-iterative and iterative reconstruction. In addition, we present several research trends in this direction, including deep learning-based image reconstruction and other advanced real-time cardiac MRI strategies that reconstruct images acquired from real-time free-breathing techniques.

• Clinical Endoscopy
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• v.55 no.4
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• pp.549-557
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• 2022

Background/Aims: Digital single-operator cholangioscopy (DSOC)-guided mapping biopsy (DMB) and tube-assisted mapping biopsy (TMB) are two techniques used for preoperative evaluation of biliary tract cancer (BTC). However, data regarding the diagnostic performance of these techniques are limited. Methods: We retrospectively examined consecutive patients with BTC who underwent either technique at our institution between 2018 and 2020. We evaluated the technical success rate, adequate tissue acquisition rate, and diagnostic performance of these techniques for the evaluation of lateral spread of BTC. Results: A total of 54 patients were included in the study. The technical success rate of reaching the target sites was 95% for DMB and 100% for TMB. The adequate tissue acquisition rate was 61% for DMB and 69% for TMB. The adequate tissue acquisition rate was low, especially for target sites beyond the secondary biliary radicles. The sensitivity of DMB alone was 39%, which improved to 65% when combined with visual impression. Experts demonstrated a higher negative predictive value and diagnostic accuracy with respect to both DSOC visual impression and DMB for the evaluation of lateral spread of BTC compared to trainees. Conclusions: Adequate tissue acquisition rates were similar between the two techniques. Since DMB requires expertise, TMB may be an acceptable option when DSOC is unavailable or when DSOC expertise is limited.

• Journal of the Korean Society of Visualization
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• v.2 no.1
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• pp.52-56
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• 2004

Several visualization techniques of laser diagnostics are presented for combustion phenomena, including Mie scattering for flow, Rayleigh and Raman scattering spectroscopy for major species, laser-induced fluorescence for minor species, and laser-induced incandescence for soot. These techniques have been applied to understand the various combustion phenomena more clearly, including buoyancy-dominant flow system, diffusion flam oscillation, laminar and turbulent lifted flames, flame propagation along a vortex ring, and soot zone characteristics. The usefulness of laser diagnostics on a better understanding of physical mechanism is demonstrated.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.357-361
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• 2006

This paper dealt with the performance evaluation and the diagnostic techniques of lightning arresters for DC electric traction vehicle. Field Measurements on the protective operation of lightning arresters against surge currents were carried out on running vehicles to acquire the data necessary for the diagnosis. The frequency and the magnitude of surge events were analyzed. Surge currents of $1\sim3$ times were recorded in one running service route and their magnitudes were ranges of $150A\sim2kA$. Also, an acceleration experiment on a lightning arrester by the standard lightning impulse current of 8/20 us and 5 kA was performed to know the aging characteristics. After the surge current application of 3,000 times, the reference voltage decreased by 4.5 %, and the leakage current was below 10 uA at the continuous operating voltage and about 50 uA at the rated voltage. From the experimental results, we propose a decision level of leakage current for the arrester used in this paper and designed an arrester tester which analyzes arrester condition by the magnitude of leakage current.