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Your search keyword '"Hwang, J. S."' showing total 38 results
Start Over Author "Hwang, J. S." Publisher wiley
38 results on '"Hwang, J. S."'

13. Analysis of optical loss on blue-violet laser diodes

Author

Son, J. K., primary, Hwang, J. S., additional, Lee, S. N., additional, Sakong, T., additional, Paek, H., additional, Chae, S., additional, Kim, H. K., additional, Nam, O., additional, Kim, J. Y., additional, Cho, Y. H., additional, and Park, Y., additional

Published
2006
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36. Monte Carlo estimation of extrapolation of quality-adjusted survival for follow-up studies.

Author

Hwang JS and Wang JD

Subjects
Computer Simulation, Female, Follow-Up Studies, Humans, Life Tables, Linear Models, Male, Middle Aged, Proportional Hazards Models, Survival Rate, Taiwan epidemiology, Monte Carlo Method, Quality-Adjusted Life Years, Survival Analysis
Abstract

The expected quality-adjusted survival (QAS) for an index population with a specific disease can be estimated by summing the product of the survival function and the mean quality of life function of the population. In many follow-up studies with heavy censoring, the expected QAS may not be well estimated due to the lack of data beyond the close of follow-up. In this paper, we first created a reference population from the life tables of the general population according to the Monte Carlo method. Secondly, we fitted a simple linear regression line to the logit of the ratio of quality-adjusted survival functions for the index and reference populations up to the end of follow-up. Finally, combining information on the reference population with the fitted line, we predicted the expected quality-adjusted survival curve beyond the follow-up period for the index population. Simulation studies have shown that the simple Monte Carlo estimation procedure is a potential approach for estimating expected QAS and the survival function beyond the follow-up with a certain degree of accuracy., (Copyright 1999 John Wiley & Sons, Ltd.)

Published
1999
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37. Estimation of expected quality adjusted survival by cross-sectional survey.

Author

Hwang JS, Tsauo JY, and Wang JD

Subjects
Bias, Health Services Research, Humans, Reproducibility of Results, Treatment Outcome, Cross-Sectional Studies, Life Tables, Mortality, Quality-Adjusted Life Years, Survival Analysis
Abstract

To compare both mortality and quality of life (QOL) across different illnesses, we propose an estimator to calculate the expected quality adjusted survival (QAS) by multiplying the QOL into the survival function. While the survival function can be determined by the usual life table method, the QOL data can be collected by a cross-sectional survey among patients who are currently surviving. The area under the QAS curve is thus the expected utility of health of the specific illness, which may take a common unit of quality adjusted life year ready for outcome evaluation and policy decision. A simulation is performed to demonstrate that the proposed estimator and its standard error are relatively accurate. The limitations and guidelines for using this estimator are also discussed.

Published
1996
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38. Biotransformation of acrylonitrile to acrylamide using immobilized whole cells of Brevibacterium CH1 in a recycle fed-batch reactor.

Author

Hwang JS and Chang HN

Abstract

Acrylamide was produced from acrylonitrile using immobilized Brevibacterium CH1 cells that were isolated from soil and found to possess nitrile hydratase activity. The reaction conditions and stability of the enzyme activity were studied. The conversion yield was nearly 100%, including a trace amount of acrylic acid. This strain showed strong activity of nitrile hydratase toward acrylonitrile and extremely low activity of amidase toward acrylamide. A packed bed reactor was operated in a fed-batch manner for acrylamide production of high concentration. The acrylonitrile concentration was maintained below 3% and the operating temperature at 4 degrees C to minimize enzyme deactivation.

Published
1989
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