• Proceedings of the Korean Magnestics Society Conference
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• 2001.04a
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• pp.18-19
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• 2001

• Proceedings of the Korean Magnestics Society Conference
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• 1994.03a
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• pp.9-10
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• 1994

• Proceedings of the Korean Vacuum Society Conference
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• 2001.07a
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• pp.88-89
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• 2001

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.116-117
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• 2002

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.525-531
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• 1995

Three quality factors of bread during baking process were measured to develop neural network models for bread baking process. Firstly, volume and browning changes during bread baking process were measured using image processing technique and temperature changes inside the bread during process were measured by K-type thermocouples. Relationships among them showed nonlinearity. Secondly, multilayer perception structure with error back propagation learning was used to construct neural network models. Three neural network models for volume, browning, and bread temperature were developed respectively. Developed models showed good performance with predictive error of 4.62% for volume and browning changes after 30 seconds, 7.38% for volume and browning changes after 2 minutes, and 1.09% for temperature change inside the bread respectively.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.821-831
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• 2021

In order to calibrate energy and efficiency using the PENELOPE Code, a PENELOPE simulation was performed using a volume source. Here, we want to verify peak efficiency and usefulness by performing simultaneous measurement and correction. calculate the coincident sum correction for all volumes, first subdivide the volumes of the cylinder and the four Marinelli beakers into three heights again. Therefore, the simultaneous measurement correction coefficient in three areas and the simultaneous measurement correction coefficient for the entire volume source are calculated as output. At low energies, the j value for each source volume (50-300 ml) is small and increases significantly in the high energy range. Simulation results showed good agreement within 2.5% for all source volumes except for 50 ml and 300 ml, which were up to 4%. This means that the correction for the simultaneous measurement effect during measurement is effective. In addition. Based on this, it can be confirmed that there is an advantage to improve the detection efficiency when measuring various sources and environmental samples.

• The Journal of the Acoustical Society of Korea
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• v.19 no.6
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• pp.10-16
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• 2000

A new algorithm for estimating bladder volume for portable bladder volume measurement system is proposed. Given the actual image of a bladder, edges between bladder wall and urine are extracted first. Axes are calculated from these data and actual cross section shape is obtained by filtering. Since ordinary shape of a bladder is irregular, two cross-sections(transverse and longitudinal) are considered. With the area of a longitudinal cross-section projected along the axes of transverse cross-section, or vice versa, two estimated volume are obtained. Averaging these two value yields the volume of the bladder. Applied to actual experiments, the proposed algorithm showed explicitly good results in comparison with the conventional techniques.

• The Korean Journal of Nuclear Medicine
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• v.37 no.2
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• pp.73-82
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• 2003

Objectives: A new software (Cardiac SPECT Analyzer: CSA) was developed for quantification of volumes and election fraction on gated myocardial SPECT. Volumes and ejection fraction by CSA were validated by comparing with those quantified by Quantitative Gated SPECT (QGS) software. Materials and Methods: Gated myocardial SPECT was peformed in 40 patients with ejection fraction from 15% to 85%. In 26 patients, gated myocardial SPECT was acquired again with the patients in situ. A cylinder model was used to eliminate noise semi-automatically and profile data was extracted using Gaussian fitting after smoothing. The boundary points of endo- and epicardium were found using an iterative learning algorithm. Enddiastolic (EDV) and endsystolic volumes (ESV) and election fraction (EF) were calculated. These values were compared with those calculated by QGS and the same gated SPECT data was repeatedly quantified by CSA and variation of the values on sequential measurements of the same patients on the repeated acquisition. Results: From the 40 patient data, EF, EDV and ESV by CSA were correlated with those by QGS with the correlation coefficients of 0.97, 0.92, 0.96. Two standard deviation (SD) of EF on Bland Altman plot was 10.1%. Repeated measurements of EF, EDV, and ESV by CSA were correlated with each other with the coefficients of 0.96, 0.99, and 0.99 for EF, EDV and ESV respectively. On repeated acquisition, reproducibility was also excellent with correlation coefficients of 0.89, 0.97, 0.98, and coefficient of variation of 8.2%, 5.4mL, 8.5mL and 2SD of 10.6%, 21.2mL, and 16.4mL on Bland Altman plot for EF, EDV and ESV. Conclusion: We developed the software of CSA for quantification of volumes and ejection fraction on gated myocardial SPECT. Volumes and ejection fraction quantified using this software was found valid for its correctness and precision.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.208-209
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• 2000

기존의 CRT(cathode-ray tube)를 사용한 TV, 모니터와 같은 디스플레이는 부피가 커서 공간을 많이 차지하고 휴대품으로는 거의 사용이 불가능하였다. 그러나, 평판 디스플레이의 하나인 LCD(liquid crystal display)는 소비 전력이 작고 부피가 작아서 게임기, Note-book PC와 같은 휴대용으로는 물론 PC용 모니터와 같은 사무용 디스플레이, TV와 같은 가정용 디스플레이를 대체해 나가고 있다. (중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.160-162
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• 2017

When rubber elastomer has contact with fuel, since the component and additive having low molecular weight can flow out, the physical properties of both elastomer and fuel could be hindered. In order to predict the life of the rubber elastomer, this study is to determine the change of weight, thickness, hardness, strain, and compression set as mechanical properties of the sealant rubber O-ring, which was dependent on volume, temperature, and storage time of the contacted fuel. We also determined purity of fuel via GC analysis and measured gross heat of combution. The results could be used as a reference to evaluate the life of the rubber elastomer.