Results 71 to 80 of about 2,737 (182)
Adaptive eigenvalue computations using Newton's method on the Grassmann manifold
, 2002 We consider the problem of updating an invariant subspace of a large and structured Hermitian matrix when the matrix is modified slightly. The problem can be formulated as that of computing stationary values of a certain function with orthogonality ...
Elden, Lars,, Lundstrom, E.
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The Accuracy Smoothness Dilemma in Prediction: A Novel Multivariate M‐SSA Forecast Approach
Journal of Time Series Analysis, EarlyView.ABSTRACT Forecasting presents a complex estimation challenge, as it involves balancing multiple, often conflicting, priorities and objectives. Conventional forecast optimization methods typically emphasize a single metric, such as minimizing the mean squared error (MSE), which may neglect other crucial aspects of predictive performance. To address this
Marc Wildi
wiley +1 more source
Optimal Portfolio Choice With Cross‐Impact Propagators
Mathematical Finance, EarlyView.ABSTRACT We consider a class of optimal portfolio choice problems in continuous time where the agent's transactions create both transient cross‐impact driven by a matrix‐valued Volterra propagator, as well as temporary price impact. We formulate this problem as the maximization of a revenue‐risk functional, where the agent also exploits available ...
Eduardo Abi Jaber +2 more
wiley +1 more source
New Phytologist, EarlyView.Summary Arbuscular mycorrhizal fungi (AMF) are widespread plant symbionts that enhance nutrient acquisition and influence ecosystem productivity. Previous chromosome‐level assemblies of the model species Rhizophagus irregularis revealed a two‐compartment genome architecture (active A and repressed B chromatin compartments), yet its conservation across ...
Ken Mugambi +10 more
wiley +1 more source
Computing Accurate Eigensystems of Scaled Diagonally Dominant Matrices
, 1990 n fi When computing eigenvalues of symmetric matrices and singular values of general matrices i nite precision arithmetic we in general only expect to compute them with an error bound pron portional to the product of machine precision and the norm of ...
James Demmel, Jesse Barlow
core
The Natural Components of a Regular Linear System
Oxford Bulletin of Economics and Statistics, EarlyView.ABSTRACT The analysis of a finite‐dimensional regular linear system may be simplified by separating the system into its natural components. The natural components are smaller linear systems on separate subspaces whose dimensions sum to the dimension of the original linear system.
Brendan K. Beare, Phil Howlett
wiley +1 more source
Asymptotic spectral properties of totally symmetric multilevel Toeplitz matrices
, 2006 Let n=(n1,…,nk) be a multiindex and κ(n̲)=∏j=1knj. We say that n→∞ if ni→∞, 1⩽i⩽k. If r=(r1,…,rk) and s=(s1,…,sk), let ∣r−s∣=(∣r1−s1∣,…,∣s1−sk∣). We say that a multilevel Toeplitz matrix of the form Tn̲=[t|r̲-s̲|]r̲,s̲=1̲∞̲ is totally symmetric.
Trench, William F., William F. Trench
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, 2011 The asymptotic formulas with large values of parameter for solutions of singular differential equation allow us to estimate Green\u27s function of the boundary-value problem.
Makhnei, O.V., Tatsii, R.M.
core
Irbl: An Implicitly Restarted Block Lanczos Method for Large-Scale Hermitian Eigenproblems
, 2003 The irbleigs code is an implementation of an implicitly restarted block-Lanczos method for computing a few selected nearby eigenvalues and associated eigenvectors of a large, possibly sparse, Hermitian matrix A.
Baglama, James +6 more
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The Journal of Physiology, EarlyView.Abstract figure legend Depolarization and repolarization duration analysis was conducted in preadolescent groups with IUGR and controls using a 12‐lead ECG. Principal component analysis was applied over the 12‐lead ECGs to generate spatially transformed leads better suited for robust ECG fiducial points detection.
Freddy L. Bueno‐Palomeque +5 more
wiley +1 more source