• Journal of the Optical Society of Korea
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• v.10 no.2
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• pp.91-95
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• 2006

Blood pressure was predicted from photoplethysmography (PPG). To obtain PPG, backscattered light from a fingertip was measured and its waveform was analyzed. Systolic upstroke time and diastolic time in the pulse waveform were used as parameters to predict blood pressure. The experiment was carried out with five subjects on five different days. The systolic upstroke time had a correlation coefficient of -0.605 with respect to systolic blood pressure and the diastolic time had a correlation coefficients of -0.764 for diastolic pressure. This PPG method does not require an air-cuff installation on the arm and can predict blood pressure continuously. This simple LED/photo detector setup can be a good candidate for nonconstrained monitoring of blood pressure variations.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 1998.03a
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• pp.8-8
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• 1998

• Clinics in Shoulder and Elbow
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• v.5 no.1
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• pp.37-41
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• 2002

Purpose : To evaluate the effect of radial head resection on longevity in nonconstrained total elbow arthroplasty, Materials and Methods : The results of 20 cases of radial head replaced Pritchard ERS and 18 cases of radial head excised Kudo elbow was followed for 6 to 16 years, 10.6 years in average. The rate of loosening, osteolysis, radial head subluxation, joint dislocation and valgus deformity were compared between the two groups. Results'There was no exaggerated cubitus valgus in Pritchard ERS group. However there developed one case of delayed subluxation of radial head occurred in 6 years postoperatively, one case of loosening, and one case of sponta- neous fracture of humeral shaft due to osteolysis. In Kudo elbow group,5 cases (27.8%) showed exaggerated valgus deformity with instability. There were one case of loosening and one case of delayed dislocation occurred in a year postoperatively. Conclusion : The most clear feature of Kudo elbow was exaggerated cubitus valgus. However, the ostolysis was developed in both groups and there was no difference in rate of the other complications between the two groups.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.101-104
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• 1990

The program which could determine cross-sectional dimensions of the box girder bridge at tile stage of preliminary design was developed using the optimal technique in this study. It could minimize the cost and time required in the design of box girder bridges and the construction with the prestressed precast segmental method. Objective cost function consisted of four independent variables such as widths and depth of the cross-section. The Nelder-Mead method was used to solve the nonconstrained nonlinear problem like this.