• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.333-338
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• 1997

A hollow crankshaft is considered as part of an effort to reduce the weight of the automobile powertrain. Since the resulting mass reduction alters both the inertia and stiffness properties of the crankshaft, the vibration characteristics of the hollow crankshaft needs to be investigated in comparison with the original solid crankshaft. The crankshafts are modeled by 38 lumped mass and stiffness elements, in which the dynamic parameters for each lumped element are obtained by the finite element calculation. The fluid-film bearings supporting the crankshaft give rise to linear spring and damping elements that can be derived from the hydrodynamic bearing model. The transfer matrix method is applied to yield the natural frequencies and mode shapes of the crankshaft vibration. The natural frequencies of the hollow crankshaft are founded to be greater than that of the solid crankshaft, and the incorporation of the bearing stiffness tends to accentuate the difference.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.620-626
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• 2018

Recently, fuel cell field is receiving much attention as an environmentally friendly energy in the world. Among the various types of fuel cells, in the case of PEMFC, ions move through the membrane in the middle of the unit cell. Therefore, proper moisture is required inside the PEMFC. In the case of membrane type humidifier, flat membrane or hollow fiber membrane is mainly used. Since various parameters can change the performance, the performance investigation has to be carried out with parameters. In this study, water transport of hollow fiber membrane was investigated in terms of principle operating conditions such as temperature and flow rate.

• Elastomers and Composites
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• v.55 no.4
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• pp.277-280
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• 2020

In this study, mesoporous hollow silica spheres were synthesized using a polystyrene core and cetyltriammonium chloride (CTACl) as a pore template, and a low-cost water glass instead of expensive tetraethyl orthosilicate (TEOS) as a precursor. In addition, the material was synthesized by varying the concentration of polystyrene. Later, the polystyrene core and CTACl were removed by firing in a high-temperature heat-treatment process. The synthesized product was analyzed by various methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and N2-sorption analysis. It was confirmed that the hollow silica sphere had a hexagonal structure with a Brunauer-Emmett-Teller (BET) specific area of 1623 ㎡/g.

• Journal of Digestive Cancer Research
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• v.8 no.1
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• pp.61-64
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• 2020

Ablative therapy has drawn attention for cancer treatment as minimally invasive therapy. Recently, irreversible electroporation which has a different concept from the existing ablation method has emerged. Although gastrointestinal tract cancer is commonly managed by ablation such as liver, pancreas cancer, hollow viscus cancer is extremely challenging for applying ablative therapy because of its high perforation risk. Therefore, several studies about hollow viscus irreversible electroporation will be introduced in this review regarding its pre-clinical relevance.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.503-504
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• 1989

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.261-262
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• 2010

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.174-175
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.351-352
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• 2007

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1410-1412
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• 2009

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1998.05a
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• pp.150-151
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• 1998