• Title/Summary/Keyword: Statistical Moments

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A Statistical Analysis of Joint Moments Acting on Men Performing a Seated Dynamic Task (앉은 자세에서 동적 작업을 수행할 때 작용하는 관절 모멘트의 통계학적 해석)

  • Jung, Ho-Il;Son, Kwon
    • Progress in Medical Physics
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    • v.2 no.2
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    • pp.161-173
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    • 1991
  • A statistical approach was carried out to analyze joint moments acting on the six subjects performing a right-handed seated task. The dynamic task analyzed consisted of moving a hand-held weight of lkg mass back and forth in front of a subject's chest at the shoulder level in an upright seated position. We used experimental data obtained in the Biomechanics Laboratory of the University of Michigan. Based on the acquired data from three trials by each subject, moments were calculated using a 3-dimensional biomechanical model at such articulations as wrist, elbow, shoulder, the third lumbar spine, hip, knee, and ankle joints. The linear correlation and the two way analysis of variance were applied to the calculated joint moments in order to investigate inter-subject and inter-trial varations. The results obtained showed that the largest magnitude and deviation of moment was found at the third lumbar spine, that any linear relationship could not be found between moment and its equivalents attempted in this study, and that the maximum value and deviation of moment acting on each joint were statistically the same for all three trials but those were statistically not the same for all six subjects.

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Probability distribution and statistical moments of the maximum wind velocity

  • Schettini, Evelia;Solari, Giovanni
    • Wind and Structures
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    • v.1 no.4
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    • pp.287-302
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    • 1998
  • This paper formulates a probabilistic model which is able to represent the maximum instantaneous wind velocity. Unlike the classical methods, where the randomness is circumscribed within the mean maximum component, this model relies also on the randomness of the maximum value of the turbulent fluctuation. The application of the FOSM method furnishes the first and second statistical moments in closed form. The comparison between the results herein obtained and those supplied by classical methods points out the central role of the turbulence intensity. Its importance is exalted when extending the analysis from the wind velocity to the wind pressure.

The transmuted GEV distribution: properties and application

  • Otiniano, Cira E.G.;de Paiva, Bianca S.;Neto, Daniele S.B. Martins
    • Communications for Statistical Applications and Methods
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    • v.26 no.3
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    • pp.239-259
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    • 2019
  • The transmuted generalized extreme value (TGEV) distribution was first introduced by Aryal and Tsokos (Nonlinear Analysis: Theory, Methods & Applications, 71, 401-407, 2009) and applied by Nascimento et al. (Hacettepe Journal of Mathematics and Statistics, 45, 1847-1864, 2016). However, they did not give explicit expressions for all the moments, tail behaviour, quantiles, survival and risk functions and order statistics. The TGEV distribution is a more flexible model than the simple GEV distribution to model extreme or rare events because the right tail of the TGEV is heavier than the GEV. In addition the TGEV distribution can adjusted various forms of asymmetry. In this article, explicit expressions for these measures of the TGEV are obtained. The tail behavior and the survival and risk functions were determined for positive gamma, the moments for nonzero gamma and the moment generating function for zero gamma. The performance of the maximum likelihood estimators (MLEs) of the TGEV parameters were tested through a series of Monte Carlo simulation experiments. In addition, the model was used to fit three real data sets related to financial returns.

Different estimation methods for the unit inverse exponentiated weibull distribution

  • Amal S Hassan;Reem S Alharbi
    • Communications for Statistical Applications and Methods
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    • v.30 no.2
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    • pp.191-213
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    • 2023
  • Unit distributions are frequently used in probability theory and statistics to depict meaningful variables having values between zero and one. Using convenient transformation, the unit inverse exponentiated weibull (UIEW) distribution, which is equally useful for modelling data on the unit interval, is proposed in this study. Quantile function, moments, incomplete moments, uncertainty measures, stochastic ordering, and stress-strength reliability are among the statistical properties provided for this distribution. To estimate the parameters associated to the recommended distribution, well-known estimation techniques including maximum likelihood, maximum product of spacings, least squares, weighted least squares, Cramer von Mises, Anderson-Darling, and Bayesian are utilised. Using simulated data, we compare how well the various estimators perform. According to the simulated outputs, the maximum product of spacing estimates has lower values of accuracy measures than alternative estimates in majority of situations. For two real datasets, the proposed model outperforms the beta, Kumaraswamy, unit Gompartz, unit Lomax and complementary unit weibull distributions based on various comparative indicators.

Use of beta-P distribution for modeling hydrologic events

  • Murshed, Md. Sharwar;Seo, Yun Am;Park, Jeong-Soo;Lee, Youngsaeng
    • Communications for Statistical Applications and Methods
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    • v.25 no.1
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    • pp.15-27
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    • 2018
  • Parametric method of flood frequency analysis involves fitting of a probability distribution to observed flood data. When record length at a given site is relatively shorter and hard to apply the asymptotic theory, an alternative distribution to the generalized extreme value (GEV) distribution is often used. In this study, we consider the beta-P distribution (BPD) as an alternative to the GEV and other well-known distributions for modeling extreme events of small or moderate samples as well as highly skewed or heavy tailed data. The L-moments ratio diagram shows that special cases of the BPD include the generalized logistic, three-parameter log-normal, and GEV distributions. To estimate the parameters in the distribution, the method of moments, L-moments, and maximum likelihood estimation methods are considered. A Monte-Carlo study is then conducted to compare these three estimation methods. Our result suggests that the L-moments estimator works better than the other estimators for this model of small or moderate samples. Two applications to the annual maximum stream flow of Colorado and the rainfall data from cloud seeding experiments in Southern Florida are reported to show the usefulness of the BPD for modeling hydrologic events. In these examples, BPD turns out to work better than $beta-{\kappa}$, Gumbel, and GEV distributions.

Image Registration Based On Statistical Descriptors In Frequency Domain

  • Chang, Min-hyuk;Ahmad, Muhammad-Bilal;Lee, Cheul-hee;Chun, Jong-hoon;Park, Seung-jin;Park, Jong-an
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1531-1534
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    • 2002
  • Shape description and its corresponding matching algorithm is one of the main concerns in MPEG-7. In this paper, a new method is proposed for shape registration of 2D objects for MPEG-7 Shapes are recognized using the Hu statistical moments in frequency domain. The Hu moments are moment-based descriptors of planar shapes, which are invariant under general translation, rotational, scaling, and reflection transformation. The image is transformed into frequency domain using Fourier Transform. Annular and radial wedge distributions fur the power spectra are extracted. Different statistical features (Hu moments) are found f3r the power spectrum of each selected transformed individual feature. The Euclidean distance of the extracted moment descriptors of the features are found with respect to the shapes in the database. The minimum Euclidean distance is the candidate for the matched shape. The simulation results are performed on the test shapes of MPEG-7.

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Tracking of Moving Objects Using Morphological Segmentation, Statistical Moments and Hough Transform

  • Ahmad, Muhammad Bilal;Chang, Min-Hyuk;Park, Jong-An
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1377-1381
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    • 2003
  • This paper describes real time object tracking of 3D objects in 2D image sequences. The moving objects are segmented from the image sequence using morphological operations. The moving objects are segmented by the method of differential image followed by the process of morphological dilation. The moving objects are recognized and tracked using statistical moments. The direction of moving objects are determined by the Hough transform. The straight lines in the moving objects are found with the help of Hough transform. The direction of the moving object is calculated from the orientation of the straight lines in the direction of the principal axes of the moving objects. The direction of the moving object and the displacement of the object in the image sequence is used to calculate the velocity of the moving objects. The simulation results of the proposed method are promising on the test images.

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The Cumulants of the Non-normal t Distribution

  • Hwang, Hark
    • Journal of the Korean Statistical Society
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    • v.5 no.2
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    • pp.91-100
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    • 1976
  • The use of the statistic $t = \sqrt{n} (x-\mu)/S$, where $\bar{X) = \sum X_i/n, \mu = E(X_i), S^2 = \sum(X_i-\bar{X})^2/(n-1)$ in statistical inference is usually done under the assumption of normality of the population. If the population is not normally distributed the tabulated values of student t are no longer valid. The moments of t are obtained as a power series in $1/\sqar{n}$ whose coefficients are functions of the cumulants of X. The cumulants are obtained from the moments in the usual manner. The first eight cumulants of t are given up to terms of order $1/n^3$. The first eight cumulants of t are given up to terms of order $1/n^3$. These results extend those of Geary who gave the first six cumulants of t to order $1/n^2$.

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Spliced Image Detection Using Characteristic Function Moments of Co-occurrence Matrix (동시 발생 행렬의 특성함수 모멘트를 이용한 접합 영상 검출)

  • Park, Tae-Hee;Moon, Yong-Ho;Eom, Il-Kyu
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.5
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    • pp.265-272
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    • 2015
  • This paper presents an improved feature extraction method to achieve a good performance in the detection of splicing forged images. Strong edges caused by the image splicing destroy the statistical dependencies between parent and child subbands in the wavelet domain. We analyze the co-occurrence probability matrix of parent and child subbands in the wavelet domain, and calculate the statistical moments from two-dimensional characteristic function of the co-occurrence matrix. The extracted features are used as the input of SVM classifier. Experimental results show that the proposed method obtains a good performance with a small number of features compared to the existing methods.

Modulation classification for BPSK and QPSK signals over rayleigh fading channel (Payleigh 페이딩 채널에서 BPSK와 QPSK 신호의 변조 분류)

  • 윤동원;한영열
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.4
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    • pp.1019-1026
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    • 1996
  • A modulation type classifier based on statistical moments has been successfully employed to classify PSK signals. Previously, developed Classifiers were analyzed in AWGN channel only. In this paper, a moments-based modulation type classifier to classify BPSK and QPSK signals over Rayleigh fading channel is proposed and analyzed. The moments of received signal are evaluated with the exact distribution of the received signal and a moments-based classifier is proposed. The performance evaluation of the proposed classifier in terms of the misclassification probability for BPSK and QPSK is investigated under Rayleigh fading environment.

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