Results 41 to 50 of about 371 (117)
Discrete Dynamics in Nature and Society, 2020 We investigate the local and global character of the unique equilibrium point and boundedness of the solutions of certain homogeneous fractional difference equation with quadratic terms.
Mirela Garić-Demirović +3 more
doaj +1 more source
Cubic and quartic planar differential systems with exact algebraic limit cycles
Electronic Journal of Differential Equations, 2011 We construct cubic and quartic polynomial planar differential systems with exact limit cycles that are ovals of algebraic real curves of degree four. The result obtained for the cubic case generalizes a proposition of [9].
Ahmed Bendjeddou, Rachid Cheurfa
doaj
Quaternion rational Bézier curves
Lietuvos Matematikos Rinkinys, 2011 We extended the rational Bézier model for space curve, by allowing quaternion weights. These curves are Möbius invariant and have halved degree with respect to real Bézier curves. This simplify the analysis of curves. In general, these curves are in four
Severinas Zube
doaj +1 more source
Inverse problems for multiple invariant curves [PDF]
Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 2007 Planar polynomial vector fields which admit invariant algebraic curves, Darboux integrating factors or Darboux first integrals are of special interest. In the present paper we solve the inverse problem for invariant algebraic curves with a given multiplicity and for integrating factors, under generic assumptions regarding the (multiple) invariant ...
Cristopher, Colin +3 more
openaire +2 more sources
Application of pso for solving problems of invariant comparison of two-dimensional closed curve
Вестник СибАДИ, 2017 The problem of estimating the norm of the distance between the two closed smooth curves for pattern recognition is considered. Diffeomorphic transformation curves based on the model of large deformations is described.
Dmitry Borisovich Abramov +2 more
doaj +1 more source
ARNOLD-TYPE INVARIANTS OF CURVES ON SURFACES [PDF]
Journal of Knot Theory and Its Ramifications, 1999 Recently V. Arnold introduced Strangeness and J± invariants of generic immersions of an oriented circle to ℝ2. Here these invariants are generalized to the case of generic immersions of an oriented circle to an arbitrary surface F. We explicitly describe all the invariants satisfying axioms, which naturally generalize the axioms used by V. Arnold.
openaire +3 more sources
Multi-Component Integrable Systems and Invariant Curve Flows in Certain Geometries
Symmetry, Integrability and Geometry: Methods and Applications, 2013 In this paper, multi-component generalizations to the Camassa-Holm equation, the modified Camassa-Holm equation with cubic nonlinearity are introduced.
Changzheng Qu, Junfeng Song, Ruoxia Yao
doaj +1 more source
The Ceresa class and tropical curves of hyperelliptic type
Forum of Mathematics, SigmaWe define a new algebraic invariant of a graph G called the Ceresa–Zharkov class and show that it is trivial if and only if G is of hyperelliptic type, equivalently, G does not have as a minor the complete graph on four vertices or the loop of three ...
Daniel Corey, Wanlin Li
doaj +1 more source
On Invariants of Artin-Schreier Curves
Abstract The main goal of this article is to expand the theory of invariants of Artin-Schreier curves by giving a complete classification in genus 3 and 4. To achieve this goal, we first establish standard forms of Artin-Schreier curves and determine all isomorphisms between curves in this form.
Duque-Rosero, Juanita +4 more
openaire +2 more sources
An Invariant Geometric Feature for Inter-Subject Lumbar Curve Alignment to Detect Spondylolisthesis
IEEE AccessSpondylolisthesis classification commonly relies on the shift distance (SD) feature. This feature measures the displacement between vertebrae but is sensitive to variations in size and rotational alignment of the vertebrae.
Podchara Klinwichit +7 more
doaj +1 more source