Results 81 to 90 of about 17,709,774 (182)

Piecewise linear differential systems with an algebraic line of separation

Electronic Journal of Differential Equations, 2020
We study the number of limit cycles of planar piecewise linear differential systems separated by a branch of an algebraic curve. We show that for each $n\in\mathbb{N}$ there exist piecewise linear differential systems separated by an algebraic curve ...
Armengol Gasull, Joan Torregrosa, Xiang Zhang   +2 more
doaj  

A Sub‐Microsecond Switch Enabling SWIFT 23Na Imaging at 10.5 T

Magnetic Resonance in Medicine, Volume 96, Issue 4, Page 1991-2003, October 2026.
ABSTRACT PurposeTo enable sodium SWIFT imaging, which is a zero‐echo time imaging technique, at ultra‐high magnetic fields through the development of custom electronics hardware, and to showcase this capability with in vivo imaging results. MethodsThe custom hardware developed consists of a high‐speed optical trigger with 10 ns resolution, an in‐bore ...
Russell L. Lagore, Simon Schmidt, Edward J. Auerbach, Naoharu Kobayashi, Christoph Schildknecht, Steen Moeller, Elnaz Mahmoudi Mahmoudalilou, Štefan Zbýň, Jutta Ellermann, Gregor Adriany, Gregory J. Metzger   +10 more
wiley   +1 more source

Polynomial Preconditioning for Indefinite Matrices

Numerical Linear Algebra with Applications, Volume 33, Issue 5, October 2026.
ABSTRACT Polynomial preconditioning is an important tool in solving large linear systems and eigenvalue problems. A polynomial from GMRES can be used to precondition restarted GMRES and restarted Arnoldi. Here we give methods for indefinite matrices that make polynomial preconditioning more generally applicable. The new techniques include balancing the
Hayden Henson, Ronald B. Morgan
wiley   +1 more source

Degenerate matrix method with Chebyshev nodes for solving nonlinear systems of differential equations

Mathematical Modelling and Analysis, 1999
One of the simplest schemes of the degenerate matrix method with nodes as zeroes of Chebyshev polynomials of the second kind is considered. Performance of simple iterations and some modifications of Newton method for the discrete problem is compared ...
T. Cirulis, O. Lietuvietis
doaj   +1 more source

New method for solving strong conservative odd parity nonlinear oscillators: Applications to plasma physics and rigid rotator

AIP Advances, 2020
In the present work, a new method for solving a strong nonlinear oscillator equation of the form ẍ + F(x) = 0, where F(−x) = −F(x), is carried out. This method consists of approximating function F(x) by means of a suitable Chebyshev polynomial: F(x) ≈ P(
Ma’mon Abu Hammad, Alvaro H. Salas, S. A. El-Tantawy   +2 more
doaj   +1 more source

Reaction‐Driven Crack Propagation Controlled by Vein Extension in a Dilute Fracture System

Journal of Geophysical Research: Solid Earth, Volume 131, Issue 10, October 2026.
Abstract Permanent mineral trapping of CO2 ${\text{CO}}_{2}$ in ultramafic rocks can be accelerated if carbonate precipitation wedges open microcracks and sustains crack growth, thereby increasing permeability and reactive surface area. We develop a vein‐extension controlled model for carbonation reaction‐driven cracking in a dilute fracture system ...
Rui Feng, John Rudnicki
wiley   +1 more source

A Composite Wavelet–Rational Approach for Solving the Volterra’s Population Growth Model Over Semi-Infinite Domain

Advances in Mathematical Physics
In problems defined on a semi-infinite domain, rational Chebyshev or Laguerre functions are the generic choices of basis functions in spectral methods.
Leila Rangipoor, Tavassoli Kajani Majid, Saeid Jahangiri   +2 more
doaj   +1 more source

Mandated Annuitization, Gender‐Neutral Pricing, and the Possibility of Negative Correlation Between Risk Type and Purchase Level

Journal of Public Economic Theory, Volume 28, Issue 5, October 2026.
ABSTRACT Mandated annuitization is often proposed to eliminate the inefficiency caused by the positive correlation between risk type and purchase level in insurance markets. We revisit this solution in a mandatory annuity program with partial waiver, which is empirically relevant.
Sau‐Him Paul Lau, Yinan Ying, Qilin Zhang   +2 more
wiley   +1 more source

An Identity Involving the Integral of the First-Kind Chebyshev Polynomials

, 2018
We used the algebraic manipulations and the properties of Chebyshev polynomials to obtain an interesting identity involving the power sums of the integral of the first-kind Chebyshev polynomials and solved an open problem proposed by Wenpeng Zhang and ...
Jiayuan Hu, Xiao Wang
core   +1 more source

Observability of Linear Differential-algebraic Equations in the Class of Chebyshev Functions

Известия Иркутского государственного университета: Серия "Математика", 2017
We consider linear time-varying systems of first order ordinary differential equations unresolved with respect to the derivative of the unknown function and identically degenerate in the domain.
P.S. Petrenko
doaj   +1 more source