Results 31 to 40 of about 114,098 (264)
AppliedMathAfter linear differential systems in the plane, the easiest systems are quadratic polynomial differential systems in the plane. Due to their nonlinearity and their many applications, these systems have been studied by many authors.
Joan Carles Artés +2 more
doaj +1 more source
Quadratic systems with a symmetrical solution
Electronic Journal of Qualitative Theory of Differential Equations, 2018 In this paper we study the existence and uniqueness of limit cycles for so-called quadratic systems with a symmetrical solution: \begin{equation*} \begin{split} \frac{dx(t)}{dt}& = P_2(x,y) \equiv a_{00}+a_{10}x+a_{01}y+a_{20}x^2+a_{11}xy+a_{02}y^2 ...
Andre Zegeling, Robert Kooij
doaj +1 more source
Journal für die reine und angewandte Mathematik (Crelles Journal), 1984 Let \(u_ F(r)\) be the smallest integer such that every system of r quadratic forms in n variables, defined over a field F, has a nontrivial common zero if \(n>u_ F(r)\). Let \(u_ F(r)=\infty\) if no such integer exists. Then \(u_ F(r)\leq frac{1}{2}(r^ 2+r)u_ F(1)\) and there exist fields for which this bound is best possible when \(r=1,2,3\). If F is
openaire +2 more sources
Adaptive Model Predictive Control of a Two-wheeled Robot Manipulator with Varying Mass
Measurement + Control, 2018 This paper presents the adaptive model predictive control approach for a two-wheeled robot manipulator with varying mass. The mass variation corresponds to the robot picking and placing objects or loads from one place to another.
Mert Önkol, Coşku Kasnakoğlu
doaj +1 more source
An Optimal Generation Scheduling Approach Based on Linear Relaxation and Mixed Integer Programming
IEEE Access, 2020 This paper proposes an optimal generation scheduling approach based on linear relaxation and mixed integer programming, which is used to solve the generation dispatch problem.
Yunkai Lei +5 more
doaj +1 more source
Set simulations for quadratic systems
IEEE Transactions on Automatic Control, 2003 In this paper, we study the problem of propagating in time a bounding set for the state of a class of nonlinear quadratic systems. The sequence of bounding sets is called the set simulation of the system, and conveys useful information about the stability and qualitative behavior of the possible time responses of the system.
openaire +2 more sources
Preimages of quadratic dynamical systems [PDF]
Involve, a Journal of Mathematics, 2011 For a quadratic endomorphism of the affine line defined over the rationals we consider the problem of bounding the number of rational points that eventually land at a given constant after iteration, called pre-images of the constant. In the article "Uniform Bounds on Pre-Images Under Quadratic Dynamical Systems," it was shown that the number of ...
Hutz, Benjamin +2 more
openaire +3 more sources
Discordance Between Patient and Physician Global Assessments in Early Systemic Sclerosis
Arthritis Care &Research, EarlyView.Objective This study aims to identify factors associated with patient global assessment (PtGA) and physician global assessment (PhGA) and discordance between them in systemic sclerosis (SSc). Methods Data from adults with early SSc (<5 years) from the Collaborative National Quality and Efficacy Registry were included.
Ellen Romich +35 more
wiley +1 more source
Nests of limit cycles in quadratic systems
Advances in Nonlinear AnalysisWe give a proof of the distribution property of limit cycles in so-called quadratic systems. We prove that the possible limit cycle distributions are either (n,0)\left(n,0) or (n,1)\left(n,1) (where n∈{0}∪Nn\in \left\{0\right\}\cup {\mathbb{N}}). The aim
Zegeling André
doaj +1 more source
Systems of quadratic diophantine inequalities [PDF]
Journal de théorie des nombres de Bordeaux, 2008 Let Q 1 , ⋯ , Q r
openaire +2 more sources