• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1720-1724
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• 2012

This study describes an oscillometric-based blood pressure measuring algorithm by detecting turning points of oscillation signal from digitally filtered cuff signals of an automatic sphygmomanometer. The blood pressure measuring algorithm uses a characteristic ratios method from the turning points. The accurate values of the systolic/diastolic blood presures(SBP/DBP) are calculated using the peaks in the ranges of characteristic ratios. Performances of the proposed algorithm and four automatic sphygmomanometers are compared with the mercury manometer(manual type sphygmomanometer), regarding the SBP and DBP values of manual sphygmomanometer as the reference values. The performance test showed the proposed algorithm revealed the best results in errors and a statistical analysis. Therefore this algorithm can be usable in any automatic sphygmomanometers.ssure states. This may be compromising results for subject-independent sensibility evaluation using EEG signal.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.510-515
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• 2009

In this paper, variable characteristic ratio algorithm based on oscillometric method is proposed to enhance the accuracy of blood pressure measurement. We combined the slope-based approach and fuzzy inference technique to change the characteristic ratios of height-based method. The proposed algorithm was assessed on 255 measurements from 85 subjects and compared with the conventional height-based algorithm. The testing results showed that the developed algorithm achieved an overall grade A for both systolic and diastolic blood pressures according to the BHS protocol. And, mean standard deviation between the observers and the developed algorithm were 5.71mmHg and 6.29mmHg for systolic and diastolic pressures respectively, which also fulfilled the AAMI criteria. In conclusion, this algorithm was successfully developed and recommended for further clinical trials with the wider adult population.

• 전기의세계
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• v.26 no.4
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• pp.41-53
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• 1977

With the equivalent series circuit analyzed aby revolving field theory and drawn by using the equivalent circuit constant ratios in capacitor motor with windings not in quadrature having space harmonics in its magnetic field (the above ratios are the equivalent circuit constants for the fundamental flux to the magnetizing reactance of the circuit), the equation for the alternating torque with twice line freequency in the motor is directly derived, and the alternating torque is measured with the self-made stator vibration angle amplitude measuring apparatus that is composed of a pickup, filter, photoelectric pickoff etc. The measured values satisfactorily compared with computed values. The properties of the alternating torque characteristics for respective harmonic fluxes and the r5esultant alternating torque characteristic, the effects of the alternating torque characteristics for respective harmonic fluxes on the resultant alternating torque characteristic, the effects of the variation in the motor constants and the equivalent circuit constant ratios for the fundamental flux on the alternating torque characteristics for respective harmonic fluxes and the resultant alternating torque characteristic, are made clear, applying the equation. There exist the optimum values of the motor constants and the equivalent circuit constant ratios for the fundamental flux for decreasing the alternating torque, and the value could be determined in design by the method presented in this paper.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.3
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• pp.205-215
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• 2004

The characteristic ratio assignment (CRA) method〔1〕 is new polynomial approach which allows to directly address the transient responses such as overshoot and speed of response time in time domain specifications. The method is based on the relationships between time response and characteristic ratios($\alpha_i$ ) and generalized time constant (T), which are defined in terms of coefficients of characteristic polynomial. However, even though the CRA can apply to developing a linear controller that meets good transient responses, there are still some fundamental questions to be explored. For the purpose of this, we have analyzed several sensitivities of a linear system with respect to the changes of coefficients itself and $\alpha_i$ of denominator polynomial. They are (i) the unnormalized root sensitivity : to determine how the poles change as $\alpha_i$ changes, and (ii) the function sensitivity to determine the sensitivity of step response to the change of o, and to analyze the sensitivity of frequency response as o, changes. As an other important result, it is shown that, under any fixed T and coefficient of the lowest order of s in denominator, the step response is dominantly affected merely by $\alpha_1, alpha_2 and alpha_3$ regardless of the order of denominator higher than 4. This means that the rest of the$\alpha_i$ s have little effect on the step response. These results provide some useful insight and background theory when we select $\alpha_i$ and T to compose a reference model, and in particular when we design a low order controllers such as PID controller.

• Journal of Korean Society for Quality Management
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• v.31 no.4
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• pp.150-163
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• 2003

The purpose of this paper is to propose an interactive method using the concept of Signal­to­Noise (SN) ratios and cutting ranges for selecting the most preferred alternatives of Multiple­attribute Decision­Making(MADM) with the­smaller­the­better or the­larger­the­better characteristics. In this method the decision makers could make a grouping of attributes by their priorities. This research is based on the assumption of an equality between the attributes of MADM with the characteristics of Taguchi method. As a result, this interactive method could transform the characteristic value of Taguchi method into the size of SN ratios which are relatively easy to understand by decision makers.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.610-621
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• 1998

In parameter design introduced by Taguchi, we analyze a signal-to-noise(SN) ratio. The SN ratio is a function of the expected loss due to the variation of quality characteristic. In this paper, an easy way for developing SN ratios is presented, which can be used to several quality characteristics simultaneously in parameter design. To develop such multivariate SN ratios, the transformation method of the expected loss and combining techniques are employed. And the analysis of real empirical data for an application of the proposed method is also presented.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.11-15
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• 2005

This paper presents a method to determine the characteristic polynomial of a closed loop all-pole system in order to obtain desired transient response in terms of the overshoot and speed (rising/settling time). The method adjusts the overshoot by doing some changes in the characteristic ratios of the Bessel-Thompson filter. The closed loop speediness is then tuned by suitable choice of the generalized time constant. Simulation results are presented to evaluate the achievements and make comparison with those of a similar method.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.565-569
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• 1998

An HPLC method was developed to resolve the enantiomers of shikonin derivatives of the Lithospermi Radix. The optimum mobile phase on a Chiracel AD column was 5% isopropanol in n-hexane with folw rate of 1 ml/min. Establishment of this method made possible to determine the ratios of shikonin/acetylshikonin or alkanin/acetylalkanin in the same root. The correlation of the ratios of these substance pairs appeared characteristic for the country where they were originated from. All of the Korean species showed significantly higher ratios of shikonin/acetylshikonin and alkanin/acetylalkanin than the Chinese ones. this method would be useful to determine the orgin of Lithospermi Radix.

• Architectural research
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• v.11 no.1
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• pp.7-14
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• 2009

In this paper, we take advantage of Wavelet Transform to identify damping ratios of membrane structures under wind action. Due to the lightweight and flexibility of membrane structures, they are very sensitive to the wind load, and show a type of fluid-structure interaction phenomenon simultaneously. In this study, we firstly obtain the responses of an air-supported membrane structure by ADINA with the consideration of this characteristic, and then conduct Wavelet Transform on these responses. Based on the Wavelet Transform, damping ratios could be obtained from the slope of Wavelet Transform in a semi-logarithmic scale at a certain dilation coefficient. According to this principle, damping ratios could eventually be obtained. There are two numerical examples in this study. The first one is a simulated signal, which is used to verify the accuracy of the Wavelet Transform method. The second one is an air-supported membrane structure under wind action, damping ratios obtained from this method is about 0.05~0.09. The Wavelet Transform method could be regarded as a very good method for the the damping analysis, especially for the large spatial structures whose natural frequencies are closely spaced.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.146-153
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• 2004

The goals of this study are to investigate the feasibility of the reference state approach in determining the generalized soil-water characteristic curve that is essential for characterization of unsaturated soil behavior. The soil-water characteristic curves are obtained from a number of specimens of fine-grained residual soils compacted with different void ratios. Based on the experimental test results, the feasibility of using the liquid limit state as the reference state for predicting the soil-water characteristic curve are verified. Finally, through the regression analysis of experimental data using the equation of Fredlund and Xing (1994), a reliable method is proposed to predict the generalized soil-water characteristic curve of fine-grained residual soils using the liquid limit state as the reference.