• Proceedings of the KSME Conference
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• 2000.04a
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• pp.585-590
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• 2000

Problems involved in the numerical analysis on the forced oscillation of nonlinear oscillators such a microbubble oscillation under ultrasound and Duffing oscillator were discussed. One of the problems is proper choice of the time scale of the driving force. which is related to the numerical artifacts due to the mismatch between the natural frequency of an oscillator(or bubble) and the characteristic frequency of the applied force. Such problem may occur in a nonlinear oscillator whose behavior is crucially dependent on the frequency of the applied force. The artificial resonance problem during the numerical evaluation of such nonlinear systems was also discussed.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.691-694
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• 2003

A 49-year-old woman had thoracic back pain for several years. Chest CT scan and MRI angiography revealed descending thoracic aortic aneurysm with a maximum diameter of 69 mm. Thoracic aortography showed not only the aortic aneurysm, but also coarctation of descending thoracic aorta at the level of aortic hiatus of the diaphragm. Intercostal artery arising Adamkiewicz artery was found in descending thoracic aortic aneurysm just above the coarctation, The aneurysm with coarctation of the aorta was successfully repaired with prosthetic graft replacement under left atrio-femoral bypass.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.617-620
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• 1997

Traumatic aneurysm of both the thoracic aorta and the left ventricle are extremely rare in children because it is characterized by high mortality. We report a case which we experienced recently with sucessful outcome. A Five-year-old boy had a blunt trauma by bongo bus. He had pulmonary hemorrage and pericardial effusion complicated by multiorgan failure threatening his life. Aneurysm of LV and Descending aorta were showed by 2-D echocardiogram and MRI. The atient underwent successful corrective surgery 2 and half momths after trauma, the Postoperative status of this patient was uneventful, now he is being followed up the OPD.