• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.926-931
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• 2002

Although ceramic plates with many micro-hales are used as MCP (Micro-channel plate) for electron amplification, catalytic converters, filters, electrical insulators and thermal conductors in integrated circuits, the drilling of micro-hales in the ceramics is difficult because of their low thermal conductivity, high hardness and brittleness. Therefore, in this work, the machining of ceramic green body fellowed by sintering of green body was employed fur fabricating ceramic plates with many micro-holes. The micro-drilling of alumina green body was performed with diamond abrasive WC drills, and the cutting force w.r.t. drilling times was measured for the determination of toot life. From the investigation of the wear of micro-drill tip w.r.t. drilling times, the wear mechanism of tip during micro-drilling of ceramic green body was suggested.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.143-152
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• 2023

Although tooth wear is a normal process due to aging, severe tooth wear causes various complications such as increased tooth sensitivity, loss of tooth structure, and pulp complications. In the treatment of patients with excessive tooth wear, the evaluation of loss of vertical occlusal dimension should be prioritized. If it is necessary to increase the vertical dimension to secure the restoration space, it is important to establish a treatment plan with the comprehensive analysis and determine the minimum vertical dimension elevation. In this case, 66-year-old male patient with severe worn dentition wanted to restore masticatory function and improve esthetic restoration. In order to determine the appropriate vertical dimension of the patient, we evaluated oral examination, radiographic examination, and diagnostic cast examination, and performed rehabilitation with minimum vertical dimension elevation. As a result of observation for 8 months, the definitive prosthesis was completed with contact of all teeth in centric occlusion, and proper anterior/posterior guidance. Through the above process, satisfactory aesthetic and functional outcomes were obtained.

• Journal of Korean Physical Therapy Science
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• v.7 no.1
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• pp.311-319
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• 2000

This study was to measure whether single axis foot or the SACH foot applied to below-knee amputation patients would bring positive changes to the patients' cardiopulmonary function, and help them to overcome their disability. The experiment took place at Asan Medical Center, University of Ulsan, from July 20th to November 20th, 1999 with 10 below-knee amputation patients. The patients were asked to equip single axis foot and SACH foot by turns and lead them to walk on a treadmill which was designed to increase its steep slope. Patients heart rate and blood pressure were recorded before and after their walking, The heart rate, systolic blood pressure, diastolic blood pressure of the patients who were equipped with, either SACH foot or single axis foot, have been increased with as the slant becoming steeper. The heart rates during the experiment did not show relevant changes according to the kind of foot used and the gradient, but the changes occurred before and after the walking(p=0.0001), The similar result of systolic blood pressure was found during the waking(p=0.01). Below-knee amputation patients are expected to walk and perform the routines better, no matter what type of foot is used, as long as they wear an artificial foot properly and taking features of foot product into consideration