Browsing by Author "Chen, ST"

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Accuracy of the EasyTouch blood glucose self-monitoring system: a study of 516 cases
(2004-11-01)
Dai, KS
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Tai, DY
;
Ho, P
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Chen, CC
;
Peng, WC
Background: Self-monitoring blood glucose device is an important toot for diabetes patients to efficiently control their blood glucose concentrations. We evaluated the accuracy of EasyTouch glucose monitoring system. Methods: Capillary blood glucose concentrations measured using EasyTouch and the reference values obtained from Yellow Springs Instruments (YSI) 2300 STAT were performed in the Department of Laboratory Medicine, Wei-Gong Memorial Hospital. Results were evaluated using (1) linear regression analysis, (2) Clarke Error Grid analysis, (3) percentage of readings within a defined range of deviation from the reference value, (4) bias plots, and (5) coefficients of variation (CVs) calculated from 60 measurements in series. Results: The window of the 516 EasyTouch readings covered a range from 42 to 555 mg/dl. Linear regression analysis yielded a regression slope 0.9972, intercept 1.899 mg/dl, r(2) 0.9571, and Syx 14.89 mg/dl. A Clarke Error Grid analysis showed 100% of the EasyTouch readings in clinically acceptable zones A and B. Of the EasyTouch readings, 98.3%, 91.9%, 78.3% and 46.9% were found within +/-20%, +/-15%, +/-10%, and +/-5%, respectively, of the reference values. Further analysis showed that the percentage of EasyTouch readings within the defined intervals was similar in three glucose ranges (less than or equal to100, 101-200, and greater than or equal to201 mg/dl). The CVs for the four lots of strips (lot 1 to lot 4) ranged from 3.5 to 5.5%, 2.1 to 4.8%, 1.8 to 3.6%, and 3.0 to 5.7%, respectively. Conclusions: EasyTouch provides high accurate and precise glucose readings over a wide range of glucose concentrations. (C) 2004 Elsevier B.V. All rights reserved.
An evaluation of clinical accuracy of the EasyTouch blood uric acid self-monitoring system
(2005-03-01)
Dai, KS
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Tai, DY
;
Ho, P
;
Chen, CC
;
Peng, WC
Objectives: Self-monitoring blood uric acid device is an important tool for patients to efficiently monitor their blood uric acid concentrations. The objective of the present study was to evaluate the accuracy of EasyTouch uric acid monitoring system. Design and methods: Capillary blood uric acid concentrations measured using EasyTouch and the reference values obtained from COBAS MIRA were performed in the Department of Laboratory Medicine, Wei-Gong Memorial Hospital. Results were evaluated using (1) linear regression analysis, (2) percentage of readings within a defined range of deviation from the reference value, and (3) coefficients of variation (CVs) calculated from 60 measurements in series. Results: The window of the 177 EasyTouch readings covered a wide range from 0.1785 to 0.6367 mmol/L (3-10.7 mg/dL). Linear regression analysis yielded a regression slope of 0.975, an intercept of 0.0118 mmol/L and an R-2 of 0.8966. Of the EasyTouch readings, 64 (36.2%), 61 (34.5%), 34 (19.2%), 9 (5.08%), and 9 (5.08%) were within the intervals of <5%, 5-10%, 10-15%, 15-17%, and >17%, respectively, of the reference values. Further analysis for the performance of each lot of strips showed that both coefficients of correlation and the percentages of readings within the CLIA's criterion (+/-17%), respectively, were in a narrow range from 0.8777 to 0.9541 and from 92.1% to 100%. The CVs for the seven lots of strips (lot I to lot 7) ranged from 2.93% to 6.33%, 3.2% to 5.9%, 3.64% to 7.0%, 2.84% to 7.6%, 2.68% to 5.42%, 3.03% to 6.93%, and 3.18% to 5.17%, respectively. Conclusion: EasyTouch is an acceptable diagnostic device which provides accurate uric acid measurements. (C) 2004 The Canadian Society of Clinical Chemists. All rights reserved.
Asymptotic stability analysis for collocated direct output feedback control of flexible systems
(1997-12-01)
Lee, HK
;
Chen, ST
;
Lee, AC
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a study of asymptotic stability for the control of flexible systems. It shows that when the controller structure is a collocated direct output feedback design with positive definite feedback gain, the number and placement of sensors and actuators are the only factors required to determine necessary and sufficient conditions to ensure closed-loop asymptotic stability. The minimum number of control devices required is dependent on the maximum number of multiple eigenvalues. The positioning of the control devices is restricted by checking several simple subsidiary rank conditions.
Bayesian inference for Rayleigh distribution under progressive censored sample
(2006-05-01)
Wu, SJ
;
Chen, DH
;
Chen, ST
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資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
It is often the case that some information is available on the parameter of failure time distributions from previous experiments or analyses of failure time data. The Bayesian approach provides the methodology for incorporation of previous information with the current data. In this paper, given a progressively type 11 censored sample from a Rayleigh distribution, Bayesian estimators and credible intervals are obtained for the parameter and reliability function. We also derive the Bayes predictive estimator and highest posterior density prediction interval for future observations. Two numerical examples are presented for illustration and some simulation study and comparisons are performed. Copyright (C) 2006 John Wiley & Sons. Ltd.
Extraction of eleven model parameters for consistent reproduction of lateral bipolar snapback high-current I-V characteristics in NMOS devices
(2001-06-01)
Chen, MJ
;
Lee, HS
;
Chen, ST
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A series of literature models originally devoted to the second breakdown trigger current I-t2 in a grounded-gate nMOS transistor can further find promising potential in handling high-current I-V due to lateral bipolar snapback. This is achieved primarily by building significant linkage between bipolar current-gain beta -related parameters: 1) the collector-to-base junction voltage dependencies A(1) and A(2) of the medium-level injection beta roll-off factor; 2) the high-level beta roll-off factor A(3); and 3) the collector-to-base junction voltage dependencies A(4) and A(5) Of the collector corner current at the onset of high-level beta roll-off. The new parameters A(1) to A(5) enable a consistent I-V solution along with other existing six model parameters such as the substrate resistance R-sub and its conductivity modulation factor A(r), the impact ionization coefficients K-1 and K-2, and the emitter series resistance R-e and collector series resistance R-c. Parameter extraction except Rc is thoroughly performed using only the parametric analyzer, and opposed to the traditional procedure, impact ionization coefficients and current gains are all assessed without entering the snapback regime. Remarkably, not only excellent agreements are gotten, but also bipolar snapback I-V measured under the current pulsing condition can be separated into two distinct parts: medium- and high-level injection region. This is quite effective under R-e = R-c. Series resistance, although having very low value, is not to be absent under the high-level injection conditions. Experimental evidences from test structures with different epitaxial layer thicknesses strongly confirm the validity of the assumptions such as R-e = R-c. In light of the epitaxial layer thickness dependencies of the model parameters, the epitaxial layer thickness effect is addressed as well.
Genetic algorithm based fuzzy ID3 algorithm
(2004)
Chang, JY
;
Cho, CW
;
Hsieh, SH
;
Chen, ST
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電控工程研究所
In this paper, we propose a genetic algorithm (GA) based fuzzy ID3 algorithm to construct a fuzzy classification system with both high classification accuracy and compact rule base size. This goal is achieved by two key steps. First, we optimize by GA the parameters controlling the means and variances of fuzzy membership functions and leaf node conditions for tree construction. Second, we prune the rules of the tree constructed by evaluating the effectiveness of the rule, and the remaining rules are retrained by the same GA proposed. Our proposed scheme is tested on various famous data sets, and its results is compared with C4.5 and IRID3. Simulation result shows that our proposed scheme leads to not only better classification accuracy but also smaller size of rule base.
Optimal control of vibration suppression in flexible systems via dislocated sensor/actuator positioning
(1996-09-01)
Lee, HK
;
Chen, ST
;
Lee, AC
;
交大名義發表
;
機械工程學系
In this study, we present a new controller design method that not only effectively suppresses vibration in flexible systems, but also has the ability to save control energy. The proposed method allows integrated determination of sensor/actuator locations and feedback gain by minimizing the sum of the integral flexible system energy and the integral control energy. Also, the cost function is characterized by an effective representation of control systems, and is determined via an efficient solution of the Lyapunov equation. The optimization problem is solved by a recursive quadratic programming algorithm. The feasibility of applying this method to a simple and flexible structure confirms the direct relationship between our optimization criterion and effectiveness in vibration suppression. Copyright (C) 1996 Published by Elsevier Science Ltd