Showing 2,221 - 2,240 results of 2,448 for search '"covariance matrix"', query time: 0.15s Refine Results
  1. 2221

    Assimilation of surface soil moisture into a multilayer soil model: design and evaluation at local scale by M. Parrens, J.-F. Mahfouf, A. L. Barbu, J.-C. Calvet

    Published 2014-02-01
    “…The introduction of vertical correlations in the background error covariance matrix is also encouraging. Using a yearly cumulative distribution function (CDF)-matching scheme for bias correction instead of matching over the three years permits the seasonal variability of the soil moisture content to be better transcribed. …”
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    Article
  2. 2222

    Improved One-Class Modeling of High-Dimensional Metabolomics Data via Eigenvalue-Shrinkage by Alberto Brini, Vahe Avagyan, Ric C. H. de Vos, Jack H. Vossen, Edwin R. van den Heuvel, Jasper Engel

    Published 2021-04-01
    “…They are based on a combination of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>MD</mi></mrow></semantics></math></inline-formula> and five so-called eigenvalue-shrinkage estimators of the covariance matrix of the reference class. A simple cross-validation procedure is proposed to set the critical limit for outlier detection. …”
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    Article
  3. 2223

    mbend: an R package for bending non-positive-definite symmetric matrices to positive-definite by Mohammad Ali Nilforooshan

    Published 2020-09-01
    “…Results Different bending procedures were conducted on a 5 × 5 covariance matrix (V), V converted to a correlation matrix (C) and an ill-conditioned 1000 × 1000 genomic relationship matrix (G). …”
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    Article
  4. 2224

    Structure of the transport uncertainty in mesoscale inversions of CO<sub>2</sub> sources and sinks using ensemble model simulations by J. Noilhan, P. Ciais, F. Chevallier, C. Sarrat, O. Pannekoucke, T. Lauvaux, P. J. Rayner

    Published 2009-06-01
    “…Finally, we compute the diagonal and non-diagonal terms of the observation error covariance matrix and introduced it into our CO<sub>2</sub> flux matrix inversion for 18 days of the 2005 intensive campaign CERES over the South West of France. …”
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    Article
  5. 2225

    Dryland Crop Classification Combining Multitype Features and Multitemporal Quad-Polarimetric RADARSAT-2 Imagery in Hebei Plain, China by Di Wang, Chang-An Liu, Yan Zeng, Tian Tian, Zheng Sun

    Published 2021-01-01
    “…Three quad-polarimetric RADARSAT-2 scenes were acquired between July and September 2018, from which 117 features were extracted using the Cloude–Pottier, Freeman–Durden, Yamaguchi, and multiple-component polarization decomposition methods, together with two polarization matrices (i.e., the coherency matrix and the covariance matrix). Random forest (RF) and support vector machine (SVM) algorithms were used for classification of dryland crops and other land-cover types in this study. …”
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    Article
  6. 2226

    A haplotype of polymorphisms in <it>ASE-1</it>, <it>RAI </it>and <it>ERCC1 </it>and the effects of tobacco smoking and alcohol consumption on risk of colorectal cancer: a danish pr... by Wallin Håkan, Overvad Kim, Tjønneland Anne, Sørensen Mette, Hansen Rikke D, Raaschou-Nielsen Ole, Vogel Ulla

    Published 2008-02-01
    “…Incidence rate ratio (IRR) were estimated by the Cox proportional hazards model stratified according to gender, and two-sided 95% confidence intervals (CI) and p-values were calculated based on robust estimates of the variance-covariance matrix and Wald's test of the Cox regression parameter.…”
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    Article
  7. 2227

    Floral signals evolve in a predictable way under artificial and pollinator selection in Brassica rapa by Zu, Pengjuan, Schiestl, Florian P., Gervasi, Daniel, Li, Xin, Runcie, Daniel, Guillaume, Frédéric

    Published 2020
    “…Using the observed selection gradients and the genetic variance-covariance matrix (G-matrix) of the traits, we showed that the observed responses of most floral traits including volatiles were predicted in the right direction in both artificial- and bumblebee-selection experiment. …”
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    Article
  8. 2228

    Data Fusion for Improved Respiration Rate Estimation by Nemati, Shamim, Malhotra, Atul, Clifford, Gari D.

    Published 2011
    “…A novel index of the underlying signal quality of respiratory signals is presented and then used to modify the noise covariance matrix of the KF which discounts the effect of noisy data. …”
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    Article
  9. 2229

    On Space–Frequency Correlation of UWB MIMO Channels by Hong, Xuemin, Wang, Cheng-Xiang, Thompson, John, Allen, Ben, Ge, Xiaohu, Malik, Wasim Qamar

    Published 2012
    “…We demonstrate that, compared with a conventional model that only considers amplitude correlation, a UWB MIMO channel model taking into account both amplitude and ToA correlations leads to different theoretical maximum diversity order, numerical structure of the SF channel covariance matrix, spatial correlation function, and diversity performance. …”
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  10. 2230
  11. 2231
  12. 2232

    Learning Gaussian Graphical Models with Observed or Latent FVSs by Liu, Ying, Willsky, Alan S.

    Published 2015
    “…Regardless of the maximum degree, without knowing the full graph structure, we can exactly compute the maximum likelihood estimate with complexity O(kn[superscript 2] + n[superscript 2] log n) if the FVS is known or in polynomial time if the FVS is unknown but has bounded size. 2) The FVS nodes are latent variables, where structure learning is equivalent to decomposing an inverse covariance matrix (exactly or approximately) into the sum of a tree-structured matrix and a low-rank matrix. …”
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    Article
  13. 2233

    The gravity field, orientation, and ephemeris of Mercury from MESSENGER observations after three years in orbit by Mazarico, Erwan Matias, Genova, Antonio, Goossens, Sander, Lemoine, Frank G., Neumann, Gregory A., Solomon, Sean C., Zuber, Maria, Smith, David Edmund

    Published 2015
    “…We present a detailed analysis of the HgM005 covariance matrix, and we describe some near-circular frozen orbits around Mercury that could be advantageous for future exploration.…”
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    Article
  14. 2234

    Incremental rule splitting in generalized evolving fuzzy systems for autonomous drift compensation by Lughofer, Edwin, Pratama, Mahardhika, Skrjanc, Igor

    Published 2020
    “…The splitting technique relies on the eigendecomposition of the rule covariance matrix to adequately manipulate the largest eigenvector and eigenvalues in order to retrieve the new centers and contours of the two split rules. …”
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    Journal Article
  15. 2235

    Bayesian operational modal analysis of structures with tuned mass damper by Wang, Xinrui, Zhu, Zuo, Au, Siu-Kui

    Published 2022
    “…Analytical expressions are derived so that the ‘posterior’ (i.e., given data) covariance matrix can be determined accurately and efficiently. …”
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    Journal Article
  16. 2236

    Adaptive evolution strategies for stochastic zeroth-order optimization by He, Xiaoyu, Zheng, Zibin, Chen, Zefeng, Zhou, Yuren

    Published 2022
    “…Based on this framework, we implement a step-size adaptation rule and two covariance matrix adaptation rules, where the former can automatically tune the step-sizes and the latter are intended to cope with ill-conditioning. …”
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    Journal Article
  17. 2237
  18. 2238

    The 2dF Galaxy Redshift Survey: power-spectrum analysis of the final data set and cosmological implications by Cole, S, Percival, W, Peacock, J, Norberg, P, Baugh, C, Frenk, C, Baldry, I, Bland-Hawthorn, J, Bridges, T, Cannon, R, Colless, M, Collins, C, Couch, W, Cross, N, Dalton, G, Eke, V, De Propris, R, Driver, S, Efstathiou, G, Ellis, R, Glazebrook, K, Jackson, C, Jenkins, A, Lahav, O, Lewis, I

    Published 2005
    “…The redshift selection function is determined by dividing the survey according to rest-frame colour, and deducing a self-consistent treatment of k-corrections and evolution for each population. The covariance matrix for the power-spectrum estimates is determined using two different approaches to the construction of mock surveys, which are used to demonstrate that the input cosmological model can be correctly recovered. …”
    Journal article
  19. 2239

    Time-varying source reconstruction by Timms, R

    Published 2022
    “…To date, the majority of source localisation algorithms employ static approximations to the data covariance matrix.</p> <p>Here we make the argument that researchers should consider a Temporally Adaptive SourcE Reconstruction (TASER) approach to solving the inverse problem. …”
    Thesis
  20. 2240

    Comparison of the genetic algorithm and incremental optimisation routines for a Bayesian inverse modelling based network design by Nickless, A, Rayner, P, Erni, B, Scholes, R

    Published 2018
    “…The GA solution set showed more inconsistency if the number of iterations or population size was small, and more so for a complex prior flux covariance matrix. If the GA completed with a sub-optimal solution, these solutions were similar in fitness to the best available solution. …”
    Journal article