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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Generic one-parameter versal unfoldings of deformations of symmetric Hamiltonian systems in 1:1 resonance
No full textWe consider Hamiltonian systems in 1:1 resonance in the presence of symmetry. We give some new proofs for known results concerning the classification of generic one-parameter deformations of equivariant linear systems and the passing and splitting of eigenvalues. We show that for nonlinear systems in two degrees of freedom the bifurcation
of periodic solutions in the generic passing cases can be linearized. We conclude with several examples
The Kepler system as a reduced 4D harmonic oscillator
Get PDFIn this note it is shown how to obtain the Kepler system by geometric reduction of the 4DOF harmonic oscillator. It is shown that this reduction is a reverse KS regularization. It is furthermore shown how the integrals for the Kepler system can be represented as integrals of the harmonic oscillator. Also a representation of the Delaunay elements is computed
On the geometry of Hamiltonian systems : lecture notes seminar GISDA - Universidad del Bio Bio
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Folding a cusp into a swallowtail
Get PDFThe Hamiltonian Hopf bifurcation is described by part of a swallowtail surface. In this short note it is shown that this swallowtail is actually a non-transversally unfolded cusp singularity, and that the swallowtail surface is obtained by folding a cusp along a fold line that is tangent to the cusp and moving along the cusp
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