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The chronotherapy concept takes advantage of the circadian rhythm of
cells physiology in maximising a treatment efficacy on its target
while minimising its toxicity on healthy organs. The
object of the present paper is to investigate mathematically and
numerically optimal strategies in cancer chronotherapy. To this
end a mathematical model describing the time evolution of efficiency
and toxicity of an oxaliplatin anti-tumour treatment has been derived.
We then applied an optimal control...
Using dimension group tools and Bratteli-Vershik representations of minimal Cantor systems we prove that a minimal Cantor system and a Sturmian subshift are topologically conjugate if and only if they are orbit equivalent and Kakutani equivalent.
This paper concerns the global structure of planar systems. It is shown that if a positively bounded system with two singular points has no closed orbits, the set of all bounded solutions is compact and simply connected. Also it is shown that for such a system the existence of connecting orbits is tightly related to the behavior of homoclinic orbits. A necessary and sufficient condition for the existence of connecting orbits is given. The number of connecting orbits is also discussed.
Orbits of complete families of vector fields on a subcartesian space are shown to be
smooth manifolds. This allows a description of the structure of the reduced phase space
of a Hamiltonian system in terms of the reduced Poisson algebra. Moreover, one can give a
global description of smooth geometric structures on a family of manifolds, which form a
singular foliation of a subcartesian space, in terms of objects defined on the
corresponding family of vector fields. Stratified...
We show that the Bruschlinsky group with the winding order is a homomorphism invariant for a class of one-dimensional inverse limit spaces. In particular we show that if a presentation of an inverse limit space satisfies the Simplicity Condition, then the Bruschlinsky group with the winding order of the inverse limit space is a dimension group and is a quotient of the dimension group with the standard order of the adjacency matrices associated with the presentation.
Recently a new invariant of K-theoretic nature has emerged which is potentially very useful for the study of symbolic systems. We give an outline of the theory behind this invariant. Then we demonstrate the relevance and power of the invariant, focusing on the families of substitution minimal systems and Toeplitz flows.
This paper is devoted to a systematic study of a class of binary trees encoding the structure of rational numbers both from arithmetic and dynamical point of view. The paper is divided into three parts. The first one is mainly expository and consists in a critical review of rather standard topics such as Stern-Brocot and Farey trees and their connections with continued fraction expansion and the question mark function. In the second part we introduce two classes of (invertible and non-invertible)...
For a continuous map T of a compact metrizable space X with finite topological entropy, the order of accumulation of entropy of T is a countable ordinal that arises in the context of entropy structures and symbolic extensions. We show that every countable ordinal is realized as the order of accumulation of some dynamical system. Our proof relies on functional analysis of metrizable Choquet simplices and a realization theorem of Downarowicz and Serafin. Further, if M is a metrizable Choquet simplex,...
This work contributes to classify the dynamic behaviors of piecewise smooth systems in
which border collision bifurcations characterize the qualitative changes
in the dynamics. A central point of our investigation is the intersection of two border
collision bifurcation curves in a parameter plane. This problem is also associated with
the continuity breaking in a fixed point of a piecewise smooth map. We will relax the
hypothesis needed in [4] where...
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