The numerical solution of compressible flows in time dependent domains
This work is concerned with the numerical solution of inviscid compressible fluid flow in moving domains. Specifically, we assume that the boundary part of the domain (impermeable walls) are time dependent. We consider the Euler equations, which describe the movement of inviscid compressible fluids. We present two formulations of the Euler equations in the ALE (Arbitrary Lagrangian-Eulerian) form. These two formulations are discretized in space by the discontinuous Galerkin method. We apply a semi-implicit linearization...
The optimal control problem in coefficients for the pseudoparabolic variational inequality
The parabolic equations as a limiting case of hyperbolic and elliptic equations
The Penrose transform and Clifford analysis
[For the entire collection see Zbl 0742.00067.]The Penrose transform is always based on a diagram of homogeneous spaces. Here the case corresponding to the orthogonal group is studied by means of Clifford analysis [see F. Brackx, R. Delanghe and F. Sommen: Clifford analysis (1982; Zbl 0529.30001)], and is presented a simple approach using the Dolbeault realization of the corresponding cohomology groups and a simple calculus with differential forms (the Cauchy integral formula for solutions of...
The Penrose transform for Dirac equation
The Penrose transform is discussed for the Dirac equation corresponding to an orthogonal group in even dimensions. The authors outline a simple approach to the calculation which involves using the Dolbeault realization of cohomology groups rather than hypercohomology and spectral sequence. The details will be given elsewhere.
The periodic boundary value problem for some second order ordinary differential equations
The Poisson transform for higher order differential operators
The principal prolongation of first order -structures
The author uses the concept of the first principal prolongation of an arbitrary principal filter bundle to develop an alternative procedure for constructing the prolongations of a class of the first-order -structures. The motivation comes from the almost Hermitian structures, which can be defined either as standard first-order structures, or higher-order structures, but if they do not admit a torsion-free connection, the classical constructions fail in general.
The problema bovinum of Archimedes.
The problems of definition
The aim of this paper is to present the great kinds of definitions known in mathematical logic, their goals and their means, from their historical and philosophical background (notably thanks to the proof of two theorems), and in order to situate, within this field, the others contributions which make up this number.
The process of induction as a non-classical logic's double negation: evidence from classical scientific theories.
The processes of transformation of technological artifacts into tools for the resolution of mathematical problems.
The proposal for the modern teaching bulk data processing at secondary school [Abstract of thesis]
The Pythagorean Approach to Problems of Periodicity in Chemistry and Nuclear Physics
The rank of vector fields of Grassmannian manifolds
The Rayleigh and van der Pol wave equations, some generalizations
The regularity condition for some natural functors
The relation between the dual and the adjoint Radon transforms
[For the entire collection see Zbl 0742.00067.]Let be the set of hyperplanes in , the unit sphere of , the exterior of the unit ball, the set of hyperplanes not passing through the unit ball, the Radon transform, its dual. as operator from to is a closable, densely defined operator, denotes the operator given by if the integral exists for a.e. Then the closure of is the adjoint of . The author shows that the Radon transform and its dual can be linked by two operators...
The role of center manifolds in ordinary differential equations