• 제목/요약/키워드: Transformation parameter

검색결과 318건 처리시간 0.026초

A Maximum Power Control of IPMSM with Real-time Parameter Identification

  • Jun, Hyunwoo;Ahn, Hanwoong;Lee, Hyungwoo;Go, Sungchul;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • 제12권1호
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    • pp.110-116
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    • 2017
  • This paper proposed a new real-time parameter tracking algorithm. Unlike the convenience algorithms, the proposed real-time parameter tracking algorithm can estimate parameters through three-phase voltage and electric current without coordination transformation, and does not need information on magnetic flux. Therefore, it can estimate parameters regardless of the change according to operation point and cross-saturation effect. In addition, as the quasi-real-time parameter tracking technique can estimate parameters through the four fundamental arithmetic operations instead of complicated algorithms such as numerical value analysis technique and observer design, it can be applied to low-performance DSP. In this paper, a new real-time parameter tracking algorithm is derived from three phase equation. The validity and usefulness of the proposed inductance estimation technique is verified by simulation and experimental results.

Noninformative Priors for the Ratio of Means of Two Poisson Distributions

  • 강상실;이우동;김달호
    • Journal of the Korean Data and Information Science Society
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    • 제13권2호
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    • pp.201-207
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    • 2002
  • In this paper, Jeffrey's and reference priors are derived when the parameter of interest is the ratio of means of two in dependent Poisson distribution. To achieve the parameter orthogonality in the sense of Cox and Reid (1987), non-trivial orthogonal transformation is provided. The orthogonal transformation makes to find noninformative priors easy. Our simulation study indicates that the reference prior meet very well the target coverage probabilities in a frequentist sense. Using the real data, we compute Bayes estimator and MLE for the ratio of means based on the reference prior.

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$CaO-ZrO_2$계 소결체의 상변화와 미구조에 관한 연구 (A Study on Microstructure and Phase Transformation of Sintered Body in $CaO-ZrO_2$ System)

  • 박금철;최영섭
    • 한국세라믹학회지
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    • 제20권3호
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    • pp.217-226
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    • 1983
  • Adquate amount of calcia was added to the regent-grade Zirconia body. Here the amount and the form of calcia were 7-21 mol% and regent-grade calcium cabonate respectively. The specimens were fired at 175$0^{\circ}C$ for 0, 3, 5 and 7 hours respectively. The phase Strength X-ray diffraction analysis and Scaning electron microscopy. The results were as follows (1) As the additive amount of calcia was increased the firing linear shrinkage apparent density compressive strength and modulus of rupture decreased but the apparent porosity increased. (2) The specimens soaked and containing calcia displayed the grain growth. (3) Monoclinic and cubic zirconia were seen in the sepcimens containing 7 mol% calcia. When without soaking the specimens containing 7-10 mol% calcia had the volume change by monoclinic$\rightleftharpoons$tetragonal transformation. (4) The lattice parameter increased according as the calcia additive was increased. The specimens containing above 19mol% calcia had the costant lattice parameter. The value of that was from 5.1264 to 5.1396 $\AA$ in the case of 7 hours soaking.

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Some Remarks on the Likelihood Inference for the Ratios of Regression Coefficients in Linear Model

  • Kim, Yeong-Hwa;Yang, Wan-Yeon;Kim, M.J.;Park, C.G.
    • Journal of the Korean Data and Information Science Society
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    • 제15권1호
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    • pp.251-261
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    • 2004
  • The paper focuses primarily on the standard linear multiple regression model where the parameter of interest is a ratio of two regression coefficients. The general model includes the calibration model, the Fieller-Creasy problem, slope-ratio assays, parallel-line assays, and bioequivalence. We provide an orthogonal transformation (cf. Cox and Reid (1987)) of the original parameter vector. Also, we give some remarks on the difficulties associated with likelihood based confidence interval.

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신배전정보시스템의 세계측지계 좌표변환 (World Geodetic System Coordinate Transformation of The New Distribution Information System)

  • 장정환;권재현;김동영;조용주
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2007년도 춘계학술발표회 논문집
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    • pp.59-63
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    • 2007
  • Each country uses its own datum which well represent its topography. The uses of the space technology such as GPS and the effort of establishing the consistent data over the world, Korea changed the survey act to use a world geodetic system from January 1, 2007. In this study, spatial analysis carried out to transform the GIS DB of electric power distribution system based on the old Tokyo datum the new world geodetic system, KGD 2002. Based on the study, problems on the transformation had been identified and efficient solutions are suggested. The data used for the 7 parameter similarity transformation in this study is the blueprints of the electric equipment and base maps. It is expected that this study provide general scheme and procedure for efficient GIS DB transformation to the new world geodetic system.

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An Empirical Characteristic Function Approach to Selecting a Transformation to Normality

  • Yeo, In-Kwon;Johnson, Richard A.;Deng, XinWei
    • Communications for Statistical Applications and Methods
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    • 제21권3호
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    • pp.213-224
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    • 2014
  • In this paper, we study the problem of transforming to normality. We propose to estimate the transformation parameter by minimizing a weighted squared distance between the empirical characteristic function of transformed data and the characteristic function of the normal distribution. Our approach also allows for other symmetric target characteristic functions. Asymptotics are established for a random sample selected from an unknown distribution. The proofs show that the weight function $t^{-2}$ needs to be modified to have thinner tails. We also propose the method to compute the influence function for M-equation taking the form of U-statistics. The influence function calculations and a small Monte Carlo simulation show that our estimates are less sensitive to a few outliers than the maximum likelihood estimates.

SAMPLE ENTROPY IN ESTIMATING THE BOX-COX TRANSFORMATION

  • Rahman, Mezbahur;Pearson, Larry M.
    • Journal of the Korean Data and Information Science Society
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    • 제12권1호
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    • pp.103-125
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    • 2001
  • The Box-Cox transformation is a well known family of power transformation that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. This paper proposes a new method for estimating the Box-Cox transformation using maximization of the Sample Entropy statistic which forces the data to get closer to normal as much as possible. A comparative study of the proposed procedure with the maximum likelihood procedure, the procedure via artificial regression estimation, and the recently introduced maximization of the Shapiro-Francia W' statistic procedure is given. In addition, we generate a table for the optimal spacings parameter in computing the Sample Entropy statistic.

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A Dynamic Graphical Method for Transformations and Curvature Specifications in Regression

  • Seo, Han-Son;Yoon, Min
    • 응용통계연구
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    • 제22권1호
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    • pp.189-195
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    • 2009
  • A dynamic graphical procedure is suggested to estimate optimal response transformation parameter and a curvature function of covariates in the regression model. Augmented partial residual plot is chosen for specifying a curvature. The proposed method is compared with a different approach (Soo, 2007) and is investigated efficiency by applying it to the real and the artificial data. The method is also extended to the 3D graphical situations.

컴퓨터 화상처리를 이용한 차량번호판 추출방법 (An Extraction Medthod of Car Number Plates by Computer Picture Processing)

  • 崔亨振;吳永煥;Takeshi Agui;Masayuki Nakajima
    • 대한전자공학회논문지
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    • 제24권2호
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    • pp.309-314
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    • 1987
  • Using computer picture processing, a method of extracting the region of a car number plate is described. A modified Hough transformation, in which parameter plane is restricted, is proposed. The demerits of Hough transformation, i.e., it requires much computation time and storage capacity, are reduced by this method. Further, taking the features of a car number plate into consideration, the region of a car number plate is extracted.

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