522,155 research outputs found
Geometric characterization on the solvability of regulator equations
The solvability of the regulator equation for a general nonlinear system is discussed in this paper by using geometric method. The ‘feedback’ part of the regulator equation, that is, the feasible controllers for the regulator equation, is studied thoroughly. The concepts of minimal output zeroing control invariant submanifold and left invertibility are introduced to find all the possible controllers for the regulator equation under the condition of left invertibility. Useful results, such as a necessary condition for the output regulation problem and some properties of friend sets of controlled invariant manifolds, are also obtained
Radiation-driven Implosion in the Cepheus B Molecular Cloud
We analyze large scale mapping observations of the molecular lines in the
12CO (J=2-1), 12CO (J=3-2), 13CO (J=2-1), and 13CO (J=3-2) transition emissions
toward the Cepheus B molecular cloud with the KOSMA 3m-telescope. The
integrated intensity map of the 12CO (J=2-1) transition has shown a structure
with a compact core and a compact ridge extended in the north-west of the core.
The cloud is surrounded by an optically bright rim, where the radiation-driven
implosion (RDI) may greatly change the gas properties. The intensities of the
CO (J=3-2) transition are higher than those of the CO (J=2-1) transition along
the rim area.We find characteristic RDI structure in positionvelocity diagrams.
Non-LTE Large velocity gradient (LVG) model analysis shows that the density and
temperature at the edge are higher than that in the center. Our results provide
evidences that RDI is taking place in Cepheus B molecular cloud.Comment: 8 pages, 5 figure
Nonconforming Virtual Element Method for -th Order Partial Differential Equations in
A unified construction of the -nonconforming virtual elements of any
order is developed on any shape of polytope in with
constraints and . As a vital tool in the construction, a
generalized Green's identity for inner product is derived. The
-nonconforming virtual element methods are then used to approximate
solutions of the -harmonic equation. After establishing a bound on the jump
related to the weak continuity, the optimal error estimate of the canonical
interpolation, and the norm equivalence of the stabilization term, the optimal
error estimates are derived for the -nonconforming virtual element
methods.Comment: 33page
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