UAB Digital Repository of Documents 8 records found  Search took 0.01 seconds. 
1.
10 p, 294.1 KB Limit cycles of planar piecewise differential systems with linear Hamiltonian saddles / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Valls, Clàudia 1973- (Universidade de Lisboa. Instituto Superior Técnico. Departamento de Matemàtica)
We provide the maximum number of limit cycles for continuous and discontinuous planar piecewise differential systems formed by linear Hamiltonian saddles and separated either by one or two parallel straight lines. [...]
2021 - 10.3390/sym13071128
Symmetry, Vol. 13, Issue 7 (July 2021) , art. 1128
2 documents
2.
21 p, 420.4 KB Integrability and limit cycles via first integrals / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques)
In many problems appearing in applied mathematics in the nonlinear ordinary differential systems, as in physics, chemist, economics, etc. , if we have a differential system on a manifold of dimension, two of them having a first integral, then its phase portrait is completely determined. [...]
2021 - 10.3390/sym13091736
Symmetry, Vol. 13, Issue 9 (September 2021) , art. 1736  
3.
33 p, 4.0 MB On confinement and quarantine concerns on an seiar epidemic model with simulated parameterizations for the covid-19 pandemic / De la Sen, Manuel (Universidad del País Vasco. Instituto de Investigación y Desarrollo de Procesos IIDP) ; Ibeas, Asier (Universitat Autònoma de Barcelona. Departament de Telecomunicació i Enginyeria de Sistemes) ; Agarwal, Ravi P. (Texas A & M University. Department of Mathematics)
This paper firstly studies an SIR (susceptible-infectious-recovered) epidemic model without demography and with no disease mortality under both total and under partial quarantine of the susceptible subpopulation or of both the susceptible and the infectious ones in order to satisfy the hospital availability requirements on bed disposal and other necessary treatment means for the seriously infectious subpopulations. [...]
2020 - 10.3390/sym12101646
Symmetry, Vol. 12, Issue 10 (October 2020) , art. 1646  
4.
15 p, 5.3 MB UAV group formation collision avoidance method based on second-order consensus algorithm and improved artificial potential field / Tang, Jun (National University of Defense Technology. College of systems engineering (Xina)) ; Lao, Songyang (National University of Defense Technology. College of systems engineering (Xina)) ; Huang, Yang (National University of Defense Technology. College of systems engineering (Xina))
The problem of collision avoidance of an unmanned aerial vehicle (UAV) group is studied in this paper. A collision avoidance method of UAV group formation based on second-order consensus algorithm and improved artificial potential field is proposed. [...]
2019 - 10.3390/sym11091162
Symmetry, Vol. 11 (2019) , p. 1-15  
5.
42 p, 7.5 MB On a SIR model in a patchy environment under constant and feedback decentralized controls with asymmetric parameterizations / De la Sen, Manuel (Universidad del País Vasco. Instituto de Investigación y Desarrollo de Procesos IIDP) ; Ibeas, Asier (Universitat Autònoma de Barcelona. Departament de Telecomunicació i Enginyeria de Sistemes) ; Alonso-Quesada, Santiago (Universidad del País Vasco. Instituto de Investigación y Desarrollo de Procesos IIDP) ; Nistal, Raul (Universidad del País Vasco. Instituto de Investigación y Desarrollo de Procesos IIDP)
This paper presents a formal description and analysis of an SIR (involving susceptibleinfectious- recovered subpopulations) epidemic model in a patchy environment with vaccination controls being constant and proportional to the susceptible subpopulations. [...]
2019 - 10.3390/sym11030430
Symmetry, Vol. 11, Issue 3 (March 2019) , art. 430  
6.
38 p, 776.1 KB Darboux Integrals for Schrödinger planar vector fields via Darboux transformations / Acosta-Humánez, Primitivo B. (Universidad del Norte (Colombia). Departamento de Matemáticas y Estadística) ; Pantazi, Chara (Universitat Politècnica de Catalunya. Departament de Matemàtica Aplicada I)
In this paper we study the Darboux transformations of planar vector fields of Schrödinger type. Using the isogaloisian property of Darboux transformation we prove the "invariance" of the elements of the "Darboux Theory of Integrability". [...]
2012
SIGMA. Symmetry, Integrability and Geometry. Methods and Applications, Vol. 8 (2012) , p. 26 pages  
7.
9 p, 710.7 KB A note on the first integrals of vector fields with integrating factors and normalizers / Llibre, Jaume (Universitat Autònoma de Barcelona. Departament de Matemàtiques) ; Peralta-Salas, Daniel (Instituto de Ciencias Matemáticas (Madrid, Espanya))
2012 - 10.3842/SIGMA.2012.035
SIGMA. Symmetry, Integrability and Geometry. Methods and Applications, Vol. 8 Núm. 35 (2012) , p. 9 pages  
8.
16 p, 281.8 KB Three Duality Symmetries between Photons and Cosmic String Loops, and Macro and Micro Black Holes / Jou i Mirabent, David, 1953- (Universitat Autònoma de Barcelona. Departament de Física) ; Sciacca, Michele (Università di Palermo. Dipartimento di Scienze Agrarie e Forestali) ; Mongiovì, Maria Stella (Istituto Nazionale di Alta Matematica)
We present a review of two thermal duality symmetries between two different kinds of systems: photons and cosmic string loops, and macro black holes and micro black holes, respectively. It also follows a third joint duality symmetry amongst them through thermal equilibrium and stability between macro black holes and photon gas, and micro black holes and string loop gas, respectively. [...]
2015 - 10.3390/sym7042134
Symmetry, Vol. 7 (2015) , p. 2134-2149  

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