• Proceedings of the KWS Conference
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• 2000.04a
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• pp.222-223
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• 2000

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.213-215
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• 2003

• Proceedings of the KWS Conference
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• 1994.10a
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• pp.82-84
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• 1994

• Proceedings of the KWS Conference
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• 1999.05a
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• pp.122-123
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• 1999

• Proceedings of the KWS Conference
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• 2002.05a
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• pp.155-157
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• 2002

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.201-204
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• 2001

• Proceedings of the KWS Conference
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• 1992.10a
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• pp.110-111
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• 1992

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.423-435
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• 1998

In this paper fatigue strength reduction of butt weld with penetration defect, which can be seen frequently in the steel bridge, was assessed quantitatively. S-N curves were derived and investigated through the constant amplitude fatigue test of fully or partially penetrated welded specimen made of SWS490 steel. The fracture mechanical method was applied in order to calculate the remaining fatigue life of the partially penetrated butt welds. The fatigue limit of the fully penetrated butt welds was higher than that of category A in AASHTO's fatigue design curves, and the slope of S-N curves with 5.57 was stiffer than that of other result for welded part generally accepted as 3. The fatigue strength of the partially Penetrated butt weld was strongly influenced by the size of lack of penetration, D. It decreased drastically with increasing D from 3.9 to 14.7mm. Fracture behaviour of the partially penetrated butt weld is able to be explained obviously from the beach mark test that a semi-elliptical surface crack with small a/c ratio initiates at a internal weld root and propagates through the weld metal. To estimate the fatigue life of the partially penetrated butt weld with fracture mechanics, stress intensity factors K of 3-dimensional semi-elliptical crack were calculated by appling finite elements method and fracture mechanics parameters such as C and m were derived through the fatigue test of CT-specimen. As a result, the fatigue lives obtained by using the fracture mechanical method agreed well with the experimental results. The results were applied to Sung-Su bridge collapsed due to penetration defects in butt weld of vertical member.

• Korean Journal of Agricultural Science
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• v.51 no.2
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• pp.187-192
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• 2024

This research aimed to investigate the relationship between meat quality and muscle-to-fat ratio in specific cuts of pork (pork belly and Boston butt) utilizing magnetic resonance imaging (MRI). Twenty-eight pigs were selected, and 24 hours post-slaughter, pork belly and Boston butt samples were individually extracted from the left half carcass for MRI assessment. The MRI scans were reviewed using the Picture Archiving and Communications System. Muscle and fat volumes in the pork belly and Boston butt from the cross-sectional images captured by MRI were estimated using Vitrea workstation version 7. Subsequently, these data were processed using Vitrea post-processing software to automatically determine the volumes, measured in milliliters (mL). Additionally, a three-dimensional reconstruction of the organ being studied was generated. The relationship between regions (pork belly and Boston butt) was assessed using Pearson's correlation coefficient, and statistical analysis was conducted using Graph Pad Prism 8. The muscle-to-fat ratio determined by MRI for pork belly was 1 : 0.64, whereas for Boston butt it was 1 : 0.35. Results of comparing the muscle-fat ratio, the correlation coefficient between pork belly and Boston butt was found to be 0.6127 (R² = 0.3754, p < 0.001) based on MRI analysis. As a result of measuring the muscle-to-fat ratio using MRI as a non-destructive approach, there was a positive correlation between the muscle-to-fat ratios of pork belly and Boston butt.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.290-294
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• 1997

In this study, the welded residual stresses test was carried out with pure titanium and TIG welded material using in chemical plants an airplane frames etc.. The relationship between process parameters and residual stresses is complex since a number of factors are involved. Extensive studies have been carried out to determine the effects of various process parameters on residual stress. The result of micro-hardness about butt welded spacemen was measured of low hardness value in the melting metal zone. The residual stress of welded zone on the Titanium plate by the sectioning method and finite element method was high measured in the spacemen of high current and voltage. Also, compressive residual stress in the range of distance about 15∼20mm from the middle of the deposited metal area is very change. The result of impact test about butt welded spacemen of pure titanium plate was measured of very difference in the welded bead, heat affect zone and base metal, and be measured of high impact value in the heat affect zone. The measure result of welded residual stresses about pure titanium is high measured hen nominal steel plate. The V-Type butt welded spacemen, that of the measurement result on the welded residual stress is high measure then X-Type butt welded spacemen.