1,720,994 research outputs found
Melnikov Method for a Class of Generalized Ziegler Pendulums
No full textThe Melnikov method is applied to a class of generalized Ziegler pendulums. We find an analytical form for the separatrix of the system in terms of Jacobian elliptic integrals, holding for a large class of initial conditions and parameters. By working in Duffing approximation, we apply the Melnikov method to the original Ziegler system, showing that the first non-vanishing Melnikov integral appears in the second order. An explicit expression for the Melnikov integral is derived in the presence of a time-periodic external force and for a suitable choice of the parameters, as well as in the presence of a dissipative term acting on the lower rod of the pendulum. These results allow us to define fundamental relationships between the Melnikov integral and a proper control parameter that distinguishes between regular and chaotic orbits for the original dynamical system. Finally, in the appendix, we present proof of a conjecture concerning the non-validity of Devaney’s chaoticity definition for a discrete map associated with the system
First order moments and closure of the mass conservation equation in the mathematical theory of vehicular traffic flow
No full textOn the mathematical theory of living systems II: The interplay between mathematics and system biology
No full textOn the mathematical theory of vehicular traffic flow - I. Fluid dynamic and kinetic modelling
No full textOn the mathematical theory of vehicular traffic flow II: Discrete velocity kinetic models
No full textHaemodynamic enhancement in perforator flaps: the inversion phenomenon and its clinical significance. A study of the relation of blood velocity and flowbetween pedicle and perforatoe vessels in perforator flaps
No full textHaemodynamic enhancement in perforator flaps: the inversion phenomenon and its clinical significance. A study of the relation of blood velocity and flowbetween pedicle and perforatoe vessels in perforator flaps
No full textOn the modeling of crowd dynamics: An overview and research perspectives
No full textThis paper presents an overview of the mathematical approaches to modelingcrowd dynamics by taking into account the complexity of living systems. The contents refer to the classical representation scales (microscopic, kinetic, and
macroscopic) and to the mathematical frameworks that can be used for the modeling approach. The analysis focuses on the kinetic scale and, specifically, on developments of the mathematical kinetic theory of particles with heterogeneous
behaviors. The existing literature is critically analyzed looking ahead to researchperspectives and, more precisely, to a unified modeling strategy in view also ofswarm dynamics modeling
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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