Results 61 to 70 of about 5,113,236 (295)

The positive-definite completion problem

Transactions of the American Mathematical Society
We study the positive-definite completion problem for kernels on a variety of domains and prove results concerning the existence, uniqueness, and characterization of solutions. In particular, we study a special solution called the canonical completion which is the reproducing kernel analogue of the determinant-maximizing completion known to exist for ...
Waghmare, Kartik G., Panaretos, Victor M.   +1 more
openaire   +3 more sources

Troponin T and Neurofilament Light Chain Levels as Complementary Biomarkers of Disease Accumulation and Aggressiveness in Amyotrophic Lateral Sclerosis

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Amyotrophic lateral sclerosis (ALS) is a clinically heterogeneous neurodegenerative disease requiring reliable biomarkers to improve patient stratification and trial design. While serum neurofilament light chain (sNfL) reflects neuroaxonal stress and disease aggressiveness, troponin T (TnT) may capture complementary aspects of ...
Julia Sellin, Sofia Waldorf, Janina von der Gablentz, Torsten Grehl, Huelya Nazlican, Thomas Meyer, Julian Grosskreutz, Patrick Weydt, Sarah Bernsen   +8 more
wiley   +1 more source

Computation of Bounds for Polynomial Dynamic Systems

Algorithms
Bounds for positive definite sets such as attractors of dynamic systems are typically characterized by Lyapunov-like functions. These Lyapunov functions and their time derivatives must satisfy certain definiteness conditions, whose verification usually ...
Klaus Röbenack, Daniel Gerbet
doaj   +1 more source

State-of-Charge Estimation of Lithium-Ion Batteries Based on Dual-Coefficient Tracking Improved Square-Root Unscented Kalman Filter

Batteries, 2023
Accurate state of charge (SOC) estimation is helpful for battery management systems to extend batteries’ lifespan and ensure the safety of batteries. However, due to the pseudo-positive definiteness of the covariance matrix and noise statistics error ...
Simin Peng, Ao Zhang, Dandan Liu, Mengzeng Cheng, Jiarong Kan, Michael Pecht   +5 more
doaj   +1 more source

Checking positive definiteness or stability of symmetric interval matrices is NP-hard [PDF]

, 1994
summary:It is proved that checking positive definiteness, stability or nonsingularity of all [symmetric] matrices contained in a symmetric interval matrix is NP ...
Rohn, Jiří
core  

Impact of Age on the Diagnostic Yield of Routine EEG in People With Childhood or Juvenile Absence Epilepsy: A Cross‐Sectional Study

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Background We aimed to identify the proportion of individuals with a confirmed diagnosis of childhood absence epilepsy (CAE) or juvenile absence epilepsy (JAE) who show a negative routine EEG (rEEG), and to determine the main factors associated with this finding.
Francesco Fortunato, Alessia Giugno, Miriam Sturniolo, Enrico Fratto, Pio Zoleo, Francesca Felicia Operto, Ilaria Sammarra, Antonio Gambardella   +7 more
wiley   +1 more source

Construction of Liapunov functionals for linear Volterra integrodifferential equations and stability of delay systems

Electronic Journal of Qualitative Theory of Differential Equations, 2000
Inspired by the construction of a new Liapunov functional for linear Volterra integrodifferential equations, we prove some general stability theorems for functional differential equations with infinite delay and weaken the usual requirement for positive ...
Bo Zhang
doaj   +1 more source

Research on Channel Optimization of Ads-B Aviation Target Surveillance Radar Based on Improved Filtering Algorithm

Complexity, 2021
In order to improve the surveillance effect of the aviation target surveillance radar, this paper improves the traditional filtering algorithm and builds the channel optimization system of the ADS-B aviation target surveillance radar based on the ...
Xiaoxia Zheng, Bin Tang, Hongping Pu
doaj   +1 more source

Strict positive definiteness in geostatistics [PDF]

, 2017
Geostatistical modeling is often based on the use of covariance functions, i.e., positive definite functions. However, when interpolation problems have to be solved, it is advisable to consider the subset of strictly positive definite functions. Indeed,
POSA, Donato, DE IACO, Sandra, S. De Iaco, D. Posa   +3 more
core   +1 more source

On Positive Definiteness of Some Functions

Journal of Multivariate Analysis, 2000
Let \(E\) be a linear space over \(\mathbb{R}\) and let \(\rho(x)\) be the \(\ell^n_p\)-norm in \(\mathbb{R}^n\). A function \(f: E\to\mathbb{C}\) is called definite if \(\sum^n_{k,j=1} c_k\overline c_jf(x_k- x_j)\geq 0\) for all \(n\in\mathbb{N}\), \(x_k\in E\), \(c_k\in\mathbb{C}\) for \(k= 1,2,\dots, n\).
openaire   +4 more sources