• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.45.3-45
• /
• 2002

$\textbullet$ In this paper, a new method of estimating the rotor speed and flux is proposed. $\textbullet$ The stator currents and voltages are measurable and all the system parameters are known. $\textbullet$ There are a number of common terms in the error dynamics. $\textbullet$ This is utilized to find a simpler error model involving some auxiliary variables. $\textbullet$ Using this error model, the state estimation problem is converted into a parameter estimation prob. $\textbullet$ Some stability properties are given on the basis of Lyapunov analysis. $\textbullet$ The effectiveness of the proposed scheme is demonstrated through simulations and experiments.

• Korean Journal of Agricultural Science
• /
• v.38 no.3
• /
• pp.571-581
• /
• 2011

This study develops a mid-term preceding observation model of radish to complement an existing short-term agricultural observation model. The first purpose of the study is to extend a three seasonal classification(spring, summer, fall) of fruit-vegetables to a four seasonal classification that involves the winter additionally. This allows us to verify the reason for demand and supply unbalance and unstable price of radish. The second purpose is to construct a mid-term preceding observation model that would be used to forecast planted areas, output, monthly shipment and price. To achieve these purposes, several multiple regression models are estimated. A system is consisted of a planted areas equation, a yield equation, monthly shipment distribution equation, and monthly price equation. To calculate output an auxiliary equation is involved in the system and the consumer price index etc are considered as exogenous variables.

• The Korean Journal of Applied Statistics
• /
• v.17 no.1
• /
• pp.27-34
• /
• 2004

The Horvitz-Thompson(H-T) estimator is less efficient than PPS estimators in some cases. We use the two-stage variable transformation in order to remove the drawbacks and increase the efficiency of H-T estimator. We transform the auxiliary variable to use the Midzuno-Sen sampling scheme at the first stage. And the next stage, we also transform the study variable to reduce the variance of H-T estimator using the inclusion probability obtained from the first transformation. We compare the efficiency between a suggested modified H-T estimator and PPS estimators.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.188-191
• /
• 2002

This paper presents a method for on-line estimation of rotor time constant of induction motor. The proposed method applies a model reference adaptive system(MRAS) using rotor flux vector. The MRAS consists of two independent observers to estimate the rotor flux vector; one based on voltage equations of rotor flux vector, the other based on current equations of them. The MRAS utilizes concept of auxiliary variables to normalize observer output and decrease high-frequency components of its input. Experimental results verify the validity and usefulness of proposed method

• The Korean Journal of Applied Statistics
• /
• v.25 no.4
• /
• pp.681-695
• /
• 2012

In this paper, a family of estimators for the finite population variance investigated by Srivastava and Jhajj (1980) is studied under two different situations of random non-response considered by Tracy and Osahan (1994). Asymptotic expressions for the biases and mean squared errors of members of the proposed family are obtained; in addition, an asymptotic optimum estimator(AOE) is also identified. Estimators suggested by Singh and Joarder (1998) are shown to be members of the proposed family. A correction to the Singh and Joarder (1998) results is also presented.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.41-44
• /
• 1987

This paper is studied on the improvement of an efficiency and power factor for the single-phase induction motor with non-symmetrical cores. Since the motor construction having non-symmetrical core has the effect of reluctance torque and the rearrangement of revolving field, if core and winding design were optimized, the simple and economical permanent-capacitor-motor will be design. The most significant design variables are the degree of dissymmetry, the location of windings, and the turn-ratio between the main and auxiliary winding.

• Proceedings of the KSR Conference
• /
• 2002.10b
• /
• pp.876-883
• /
• 2002

Electric vehicle body has to be subjected to uniform load and requires auxiliary equipment such as air pipe and electric wire pipe. Especially, the cross beam supports the weight of passenger and electrical equipments. a lightweight vehicle body is salutary to save operating costs and fuel consumption. Therefore this study is to perform the size and the shape optimization of crossbeam fur electric vehicle using the method of topology optimization to introduce the concept of homogenization based on optimality criteria method which is efficient for the problem having the number of design variables and a few boundary condition. this provides the method to determine the optimum position and shape of circular hole in the cross beam and then can achieve the optimal design to reduce weight.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.113-116
• /
• 2004

No specific guidelines are for computing the shear strength of steel coupling beam connections embedded in the reinforced concrete shear wall. In this paper, a theoretical study of the strength of hybrid coupled shear wall connections is achieved. The bearing stress at failure in the concrete below the steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the steel coupling beam section to the thickness of the hybrid coupled shear wall. To revise factor affecting shear transfer strength across connections between coupled shear walls and steel coupling beam, experimental studies are achieved. The main test variables were auxiliary details of stud bolts. In this studies, these proposed equations are shown to be in good agreement with the test results reported in the paper and with other test data in the literature.

• Journal of Information Processing Systems
• /
• v.16 no.1
• /
• pp.30-41
• /
• 2020

Lines and textures are natural properties of the surface of natural objects, and their images can be sparsely represented in suitable frames such as wavelets, curvelets and wave atoms. Based on characteristics that the curvelets framework is good at expressing the line feature and wavesat is good at representing texture features, we propose a model for the weighted sparsity constraints of the two frames. Furtherly, a multi-step iterative fast algorithm for solving the model is also proposed based on the split Bergman method. By introducing auxiliary variables and the Bergman distance, the original problem is transformed into an iterative solution of two simple sub-problems, which greatly reduces the computational complexity. Experiments using standard images show that the split-based Bergman iterative algorithm in hybrid domain defeats the traditional Wavelets framework or curvelets framework both in terms of timeliness and recovery accuracy, which demonstrates the validity of the model and algorithm in this paper.

• Communications for Statistical Applications and Methods
• /
• v.17 no.6
• /
• pp.845-852
• /
• 2010

The outcomes of counts commonly occur in the area of disease mapping for mortality rates or disease rates. A Poisson distribution is usually assumed as a model of disease rates in conjunction with a gamma prior. The small area typically refers to a small geographical area or demographic group for which very little information is available from the sample surveys. Under this situation the model-based estimation is very popular, in which the auxiliary variables from various administrative sources are used. The empirical Bayes estimator under Poissongamma model has been considered with its accuracy measures. An accuracy measure using a bootstrap samples adjust the underestimation incurred by the posterior variance as an estimator of true mean squared error. We explain the suggested method through a practical dataset of hitters in baseball games. We also perform a Monte Carlo study to compare the accuracy measures of mean squared error.