In practical applications of graph transformation techniques to model transformations one often has the need for copying, deleting, or moving entire subgraphs that match a certain graph pattern. While this can be done using elementary node and edge operations, the transformation is rather cumbersome to write. To simplify the transformation, we have recently developed a novel approach that allow...

A transformation is devised to convert any chirally non-invariant lattice Dirac fermion operator into Ginsparg-Wilson Dirac fermion operator. For the standard Wilson-Dirac lattice fermion operator, the transformed new operator is local, free of O(a) lattice artifacts, has correct axial anomaly in the vacuum sector, and is not plagued by the notorious problems ( e.g., additive mass renormalizati...

The quadrics are all surfaces that can be expressed as a second degree polynomialin x, y and z. We study the Gauss map G of quadric surfaces in the 3-dimensional Euclidean space R^3 with respect to the so called L_1 operator ( Cheng-Yau operator □) acting on the smooth functions defined on the surfaces. For any smooth functions f defined on the surfaces, L_f=tr(P_1o hessf), where P_1 is t...

The generalized Fourier transform associated with a selfadjoint Sturm–Liouville operator is a unitary transformation which converts the action of this operator into a simple product by a spectral variable. For a particular operator defined on the half-line and which involves a step function, we show how to extend such a transformation to generalized functions, or distributions, with a suitable ...

0950-7051/$ see front matter 2008 Elsevier B.V. A doi:10.1016/j.knosys.2008.11.003 * Corresponding author. Tel.: +49 541 969 2534; fa E-mail address: [email protected] mueller). In the software development (e.g. with product lines or refactoring) transformations play an increasing role. To ease and automate these transformations, we propose a solution based on the operator hierarc...

In the software development (e.g. with product lines or refactoring) transformations play an increasing role. To ease and automate these transformations, we propose a solution based on the operator hierarchy concept. It allows to define transformation operator hierarchies containing different levels of transformation operators. The operators capture reusable knowledge units. The concrete realiz...

We define a quantum–mechanical time operator that is selfadjoint and compatible with the energy operator having a spectrum bounded from below. On their common domain, the operators of time and energy satisfy the expected canonical commutation relation. Pauli’s theorem is bypassed because the correspondence between time and energy is not given by the standard Fourier transformation, but by a var...