This work is designed to study helices and Bertrand curves. A circular helix is characterized by having constant curvature k 6= 0 and constant torsion t . If the ratio t k is constant, the curve is called generalized helix. ...

In this work we present the proof of a result due to Lars Hörmander which establishes a necessary condition for a linear operator with variable coefficients is globally resolvable.

In this dissertation we present a proof of a Bernard Malgrange theorem, which establishes a necessary and sufficient condition for the global solvability of a linear operator with constant coefficients.

In this work we propose a discrete predator-prey model with the purpose of analyzing the spatio-temporal dynamics of herbivorous and their predators. For that, we explicitly consider the dispersion of both species through ...

In representation theory, having a representation of a group G is equivalent to having a kG-module. Since |G-modules which are sums of irreducible kG-modules form a very important class in the theory of modules, to know ...

In this work, it is developed a study of the transverse vibrations of a system composed by two parallel strings of equal length, coupled by a viscoelastic element. The frequencies and mode shapes are obtained using modal ...

The aim of this work is to study the temporal and spatiotemporal evolution of a threedimensional system that describes a predator-prey dynamics, where the predator population can develop an infectious disease. Thus, the ...

This work researches on free and forced vibrations of a double beam coupled system. The system is regarded as two Euler-Bernoulli beams which are parallel, have the same length, are simply supported and are connected through ...

The dispersal of herbivorous insects in large plantations must be modelled by taking into account many behavioral aspects of the individual movement. The insect ability to search for (and find) better plant quality are of ...

The focal surface of a curve γ in the Euclidean 3-space is defined as the envelope of the normal planes of γ. The focal surface of γ is singular along a curve Cγ, called the focal curve or generalized evolute. This curve ...