• Journal of Electrical Engineering and information Science
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• v.3 no.2
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• pp.163-169
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• 1998

In this paper, we consider the problem of designing H$\infty$ state feedback controller for the generalized time systems with delayed states and control inputs in continuous and discrete time cases, respectively. The generalized time delay system problems are solved on the basis of LMI(linear matrix inequality) technique considering time delays. The sufficient condition for the existence of controller and H$\infty$ state feedback controller design methods are presented. Also, using some changes of variables and Schur complements, the obtained sufficient condition can be rewritten as a LMI form in terms of transformed variables. The propose controller design method can be extended into the problem of robust H$\infty$ state feedback controller design method easily.

• Journal of Korean Academy of Nursing
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• v.16 no.2
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• pp.29-35
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• 1986

The Purposes of this study are for the assessment of anxiety level and for identification for factors relating to the anxiety of the normal Pregnant women who are impendign or entering labor. The State-Trait Anxiety Inventory is used as the measure of anxiety. The results of the study are as follows: 1. The correlation between state-anxiety and trait-anxiety is 0.459 and the linear regression is y(State-anxiety) : 0.251$\chi$(Trait -anxiety)＋29.27. 2. The maternal state-anxiety is not related to the variables of the age, the educational level, the occupation, the prenatal care, parity, show, labor pain and delivery type except for the premature or early rupture of the fetal membranes. 3. The maternal trait-anxiety is not related to the above-mentioned variables.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.241-245
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• 2015

In this work we present the results of light curve analysis for two cataclysmic variables detected recently in the SDSS project: SDSS J090350.73+330036.1 and J150240.98+333423.9. Photometric observations of the first were obtained during a superoutburst in May 2010. Our observations clearly indicate the presence of superhumps in the light curves, suggesting SDSS J090350.73+330036.1 is an SU UMa dwarf nova. We determined the period of the superhumps. We also carried out fitting using a spiral-arm model in order to determine parameters of the accretion disk, hot line, and other components of this system. Photometric observations of the second, J150240.98+333423.9, were obtained during the post-maximum decline, during April-June 2012. Photometric variability of this system has been studied in an inactive state. We obtained its parameters via a combined model fitted to the observed light curves by ${\chi}^2$ minimization.

• Journal of the Korean Home Economics Association
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• v.41 no.3
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• pp.147-164
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• 2003

The purpose of this study was to investigate the effects of the family of origin variables on marital conflict. Seventy five married couples living together for less than 10 years were chosen from Seoul and Suwon cities. These subjects completed Korean Version of Family Adaptability and Cohesion Evaluation Scale Ⅱ, Individual Separation Scale, Family Rules Scale, Korea Certificated Egogram, and Marital Conflict Scale. The data were analyzed using descriptive statistics, paired-t test, and hierarchical regressions. The results were as follows: First, husbands and wives were different from each other in triangulation, family rules from family of origin and marital conflict. While husbands felt more strongly about their family rules than wives, wives perceived triangulation, and marital conflict higher than husbands. Second, husbands' controlling ego state, individuation, and family rules explained sixteen percents of husbands' marital conflict. Statistically speaking husbands' controlling ego state positively influenced on husbands' marital conflict. However, both of husbands' and wives' controlling ego states explained twelve percents of wives' marital conflict, and husbands' controlling ego state was statistically significant.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.3
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• pp.227-234
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• 2020

This paper presents the methods for the modeling and parameter optimization of the electric vehicle battery. The state variables of the battery are defined, and the test methods for battery parameters are presented. The state-space equation, which consists of four state variables, and the output equation, which is a combination of to-be-determined parameters, are shown. The parameter optimization method is the key point of this study. The least square of the modeling error can be used as an initial value of the multivariable function. It is equivalent to find the minimum value of the error function to obtain optimal parameters from multivariable function. The SIMULINK model is presented, and the 10-hour full operational range test results are shown to verify the performance of the model. The modeling error for 25 degrees is approximately 1% for full operational ranges. The comments to enhance modeling accuracy are shown in the conclusion.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.217-219
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• 2005

This paper describes implicit restated arnoldi method algorithm and Its application to small size power systems In order to observe the salient features of IRAM algorithm. Two area system with 36 state variables and England 39-bus system with 150 state variables have been tested using IRAM, and the eigenvalue results of IRAM are compared with those of the results obtained from QR method.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.120-124
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• 1987

Linear time invariant systems are considered. It is assumed that only partial state variables are observable for feedback control. In this study, a new method is presented for designing a stat e feedback controller. It is based on augmenting the original system by additional integrator and using time delayed feedback of observable variables. Several examples and its computer simulation results are given to show the effectiveness of the proposed method.

• Vacuum Magazine
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• v.2 no.1
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• pp.31-34
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• 2015

This article introduces fundamentals of self-diagnosis and predictive (or preventive) maintenance technologies for dry vacuum pumps. The state variables of dry pumps are addressed, such as the pump and motor body temperatures, consumption currents of main and booster pumps, mechanical vibration, and exhaust pressure, etc. The adaptive parametric models of the state variables of the dry pump are exploited to provide dramatic reduction of data size and computation time for self-diagnosis. Two indicators, the Hotelling's $T^2$ and the sum of squares residuals (Q), are illustrated to be quite effective and successful in diagnosing dry pumps used in the semiconductor processes.

• Journal of the Korean Home Economics Association
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• v.41 no.12
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• pp.69-89
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• 2003

The purpose of this study was to investigate the current state of divorce negotiations and to identify major variables associated with positive divorce negotiations. Survey research was conducted on 182 men and 246 women residing in Daegu Metropolitan city area who had divorced between July 1999 and June 2002 with at least one child at the time of divorce. In conclusion, it was found that divorce negotiations are more influenced by the characteristics, natures and resources of the subjects than by the nature of issues being negotiated. The study findings' implications for research and practice were also discussed.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.30-38
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• 2001

The current is considered in the conventional manoeuvering equation. This equation is represented as the nonlinear state and measurement equations in which external forces and the direction and the velocity of current are augmented as that variables. The external forces are modeled as the third-order Gauss-Markov processes and the direction and the velocity of current are assumed to be constant. The augmented state variables are estimated with extended Kalman-Bucy filter and the fixed-interval smoother. While Hwang estimated motion state variables, hydrodynamic coefficients and the current variables simultaneously by using extended Kalman filter, external forces of surge, sway and yaw and the direction and the velocity of current are the only parameters to be estimated in the estimation-before-modeling method. The current variables are satisfactorily estimated in simulation process where the measurement noise is present.