• Title/Summary/Keyword: invariant measure

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Psychological Well-being Measurement: A Comparative Study of Korean and American Adults

  • An Jeong-shin;Lambert Michael C.;Han Gyoung-hae;Cha Seung-eun
    • International Journal of Human Ecology
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    • v.5 no.2
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    • pp.13-29
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    • 2004
  • Ryff's(1989) psychological well-being measure is used to assess and sometimes compare Korean and American adults, however, there is no information regarding whether its dimensions are psychometrically invariant across, whether its items provide sufficient information for, and whether each item measures identical trait levels in, the two nations. Confirmatory factor analysis on response 1,696 Korean and 3,669 American adults, gave to the measure revealed lack of fit and absence of factorial invariance across the two nations. Item response theory revealed significant variance for items on each factor across two countries that most items yielded limited psychometric information. And that each item measure different trait levels, suggesting that in its present form, the measure might lead to misleading results for, and across the two nations.

A modification of McFadden's R2 for binary and ordinal response models

  • Ejike R. Ugba;Jan Gertheiss
    • Communications for Statistical Applications and Methods
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    • v.30 no.1
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    • pp.49-63
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    • 2023
  • A lot of studies on the summary measures of predictive strength of categorical response models consider the likelihood ratio index (LRI), also known as the McFadden-R2, a better option than many other measures. We propose a simple modification of the LRI that adjusts for the effect of the number of response categories on the measure and that also rescales its values, mimicking an underlying latent measure. The modified measure is applicable to both binary and ordinal response models fitted by maximum likelihood. Results from simulation studies and a real data example on the olfactory perception of boar taint show that the proposed measure outperforms most of the widely used goodness-of-fit measures for binary and ordinal models. The proposed R2 interestingly proves quite invariant to an increasing number of response categories of an ordinal model.

Wavelet Transform Technology for Translation-invariant Iris Recognition (위치 이동에 무관한 홍채 인식을 위한 웨이블렛 변환 기술)

  • Lim, Cheol-Su
    • The KIPS Transactions:PartB
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    • v.10B no.4
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    • pp.459-464
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    • 2003
  • This paper proposes the use of a wavelet based image transform algorithm in human iris recognition method and the effectiveness of this technique will be determined in preprocessing of extracting Iris image from the user´s eye obtained by imaging device such as CCD Camera or due to torsional rotation of the eye, and it also resolves the problem caused by invariant under translations and dilations due to tilt of the head. This technique values through the proposed translation-invariant wavelet transform algorithm rather than the conventional wavelet transform method. Therefore we extracted the best-matching iris feature values and compared the stored feature codes with the incoming data to identify the user. As result of our experimentation, this technique demonstrate the significant advantage over verification when it compares with other general types of wavelet algorithm in the measure of FAR & FRR.

A study on the Performance Improvement of Position Controller in DC Servo Motor System (직류서보전동기 위치제어기의 성능향상에 관한 연구)

  • Yoo, Jong-Gul;Lee, Kee-Sang;Hong, Soon-Chan
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.555-558
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    • 1991
  • The IESF(Integral Error and State Feedback) controller, which incorporates state feedback as a modern control scheme and integral action as a classical control scheme, has better performance than that of the conventional PID controller in linear time-invariant systems. The IESF controller requires the measurement of all the state variables. But, unfortunately, it may be difficult or impossible to measure all state variables in many applications. And the IESF controller is applicable only to pole-assignable linear time-invariant system without time delay. In this paper, new IESF controller structure was proposed which performs feedback with only measurable state variables. In order to estimate the unmeasurable state variables. It was adopted the filter mode by full-order obserber. The good performance and effectiveness of the proposed controller was confirmed by computer simulation.

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A Study on Scale-Invariant Features Extraction and Distance Measurement for Localization of Mobile Robot (이동로봇의 위치 추정을 위한 스케일 불변 특징점 추출 및 거리 측정에 관한 연구)

  • Jung, Dae-Seop;Jang, Mun-Suk;Ryu, Je-Goon;Lee, Eung-Hyuk;Shim, Jae-Hong
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.625-627
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    • 2005
  • Existent distance measurement that use camera is method that use both Stereo Camera and Monocular Camera, There is shortcoming that method that use Stereo Camera is sensitive in effect of a lot of expenses and environment variables, and method that use Monocular Camera are big computational complexity and error. In this study, reduce expense and error using Monocular Camera and I suggest algorithm that measure distance, Extract features using scale Invariant features Transform(SIFT) for distance measurement, and this measures distance through features matching and geometrical analysis, Proposed method proves measuring distance with wall by geometrical analysis free wall through feature point abstraction and matching.

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CHARACTERIZING FUNCTIONS FIXED BY A WEIGHTED BEREZIN TRANSFORM IN THE BIDISC

  • Lee, Jaesung
    • Korean Journal of Mathematics
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    • v.27 no.2
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    • pp.437-444
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    • 2019
  • For c > -1, let ${\nu}_c$ denote a weighted radial measure on ${\mathbb{C}}$ normalized so that ${\nu}_c(D)=1$. For $c_1,c_2>-1$ and $f{\in}L^1(D^2,\;{\nu}_{c_1}{\times}{\nu}_{c_2})$, we define the weighted Berezin transform $B_{c_1,c_2}f$ on $D^2$ by $$(B_{c_1,c_2})f(z,w)={\displaystyle{\smashmargin2{\int\nolimits_D}{\int\nolimits_D}}}f({\varphi}_z(x),\;{\varphi}_w(y))\;d{\nu}_{c_1}(x)d{\upsilon}_{c_2}(y)$$. This paper is about the space $M^p_{c_1,c_2}$ of function $f{\in}L^p(D^2,\;{\nu}_{c_1}{\times}{\nu}_{c_2})$ ) satisfying $B_{c_1,c_2}f=f$ for $1{\leq}p<{\infty}$. We find the identity operator on $M^p_{c_1,c_2}$ by using invariant Laplacians and we characterize some special type of functions in $M^p_{c_1,c_2}$.

A NEW LOOK AT THE FUNDAMENTAL THEOREM OF ASSET PRICING

  • Yan, Jia-An
    • Journal of the Korean Mathematical Society
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    • v.35 no.3
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    • pp.659-673
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    • 1998
  • In this paper we consider a security market whose asset price process is a vector semimartingale. The market is said to be fair if there exists an equivalent martingale measure for the price process, deflated by a numeraire asset. It is shown that the fairness of a market is invariant under the change of numeraire. As a consequence, we show that the characterization of the fairness of a market is reduced to the case where the deflated price process is bounded. In the latter case a theorem of Kreps (1981) has already solved the problem. By using a theorem of Delbaen and Schachermayer (1994) we obtain an intrinsic characterization of the fairness of a market, which is more intuitive than Kreps' theorem. It is shown that the arbitrage pricing of replicatable contingent claims is independent of the choice of numeraire and equivalent martingale measure. A sufficient condition for the fairness of a market, modeled by an Ito process, is given.

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Global Feature Extraction and Recognition from Matrices of Gabor Feature Faces

  • Odoyo, Wilfred O.;Cho, Beom-Joon
    • Journal of information and communication convergence engineering
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    • v.9 no.2
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    • pp.207-211
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    • 2011
  • This paper presents a method for facial feature representation and recognition from the Covariance Matrices of the Gabor-filtered images. Gabor filters are a very powerful tool for processing images that respond to different local orientations and wave numbers around points of interest, especially on the local features on the face. This is a very unique attribute needed to extract special features around the facial components like eyebrows, eyes, mouth and nose. The Covariance matrices computed on Gabor filtered faces are adopted as the feature representation for face recognition. Geodesic distance measure is used as a matching measure and is preferred for its global consistency over other methods. Geodesic measure takes into consideration the position of the data points in addition to the geometric structure of given face images. The proposed method is invariant and robust under rotation, pose, or boundary distortion. Tests run on random images and also on publicly available JAFFE and FRAV3D face recognition databases provide impressively high percentage of recognition.

CENTRAL LIMIT THEOREM ON CHEBYSHEV POLYNOMIALS

  • Ahn, Young-Ho
    • The Pure and Applied Mathematics
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    • v.21 no.4
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    • pp.271-279
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    • 2014
  • Let $T_l$ be a transformation on the interval [-1, 1] defined by Chebyshev polynomial of degree $l(l{\geq}2)$, i.e., $T_l(cos{\theta})=cos(l{\theta})$. In this paper, we consider $T_l$ as a measure preserving transformation on [-1, 1] with an invariant measure $\frac{1}{\sqrt[\pi]{1-x^2}}dx$. We show that If f(x) is a nonconstant step function with finite k-discontinuity points with k < l-1, then it satisfies the Central Limit Theorem. We also give an explicit method how to check whether it satisfies the Central Limit Theorem or not in the cases of general step functions with finite discontinuity points.

A summary-concept based analysis on the representative values and the measures of spread with the 9th grade Korean mathematics textbook (중학교 3학년 수학교과서 통계단원에 나타난 요약개념 분석)

  • Lee, Young-Ha;Lee, Eun-Hee
    • The Mathematical Education
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    • v.50 no.4
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    • pp.489-505
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    • 2011
  • This study is an analysis on the focus of textbooks regarding the statistical chapters of "measures of representative(central tendency) and of the spread". Applying the summary-concept criteria of Juhyeon Nam(2007), 4 kinds of aspect of the chapter; (1) definition and its teleological validity of the measures of representative, (2) definition and practical value of the measures of spread (3) distributional form on the measures of representative and of spread (4) location and scale preservation or invariance of the measures of representative and of spread were observed. On the measures of representative, some definitions were insufficient to check the teleological validity of the measure. Most definitions of the measure of spread were based on the practical view points but no preparation for the future statistical inferences were found even by implication. Some books mention about the measures of representative and of spread for distributions, but we could not find any comments on the correspondence between the sample mean and the expectation of a distribution or population mean. However it is stimulant that some books check the validity of corresponding measures with the location and scale preservation or invariant property, that were not found in the previous curriculum.