منابع مشابه
Some geometrical properties of the oscillator group
We consider the oscillator group equipped with a biinvariant Lorentzian metric. Some geometrical properties of this space and the harmonicity properties of left-invariant vector fields on this space are determined. In some cases, all these vector fields are critical points for the energy functional restricted to vector fields. Left-invariant vector fields defining harmonic maps are...
متن کاملSome new results in multiphase geometrical optics
In order to accommodate solutions with multiple phases, corresponding to crossing rays, we formulate geometrical opties for the scalar wave équation as a kinetic transport équation set in phase space. If the maximum number of phases is finite and known a priori we can recover the exact multiphase solution from an associated System of moment équations, closed by an assumption on the form of the ...
متن کاملSome Geometrical Bases for Incremental-Iterative Methods (RESEARCH NOTE)
Finding the equilibrium path by non-linear structural analysis is one of the most important subjects in structural engineering. In this way, Incremental-Iterative methods are extremely used. This paper introduces several factors in incremental steps. In addition, it suggests some control criteria for the iterative part of the non-linear analysis. These techniques are based on the geometric of e...
متن کاملSome Geometrical Aspects of Control Points for Toric Patches
We use ideas from algebraic geometry and dynamical systems to explain some ways that control points influence the shape of a Bézier curve or patch. In particular, we establish a generalization of Birch’s Theorem and use it to deduce sufficient conditions on the control points for a patch to be injective. We also explain a way that the control points influence the shape via degenerations to regu...
متن کاملData Driven Local Coordinates: Some New Topological and Geometrical Results
Certain topological and geometrical properties of data driven local coordinates (DDLC) for state-space systems as introduced in (Wolodkin et al., 1997) and (McKelvey and Helmersson, 1999) are derived. First the special case of SISO systems with McMillan degree n 1 is discussed in order to provide some insights into the geometry of the DDLC construction. Then for the MIMO case with general n it ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Časopis pro pěstování matematiky a fysiky
سال: 1906
ISSN: 1802-114X
DOI: 10.21136/cpmf.1906.122458