16 citations
6 papers
On some classes of binary matrices
Krasimir Yordzhev
The work considers the set of all binary matrices having the same number of units in each row and each column. The article specifically focuses on the matri…
On A. V. Anisimov's problem for finding a polynomial algorithm checking inclusion of context-free languages in group languages
Krasimir Yordzhev
The work investigates the problem of whether a context-free language is a subset of a group language. A.~V. Anisimov has shown that the problem of determining the unambiguity of fi…
A classification of the torsion tensors on almost contact manifolds with B-metric
Mancho Manev, Miroslava Ivanova
The space of the torsion (0,3)-tensors of the linear connections on almost contact manifolds with B-metric is decomposed in 15 orthogonal and invariant subspaces with respect to th…
An Adaptive Parallel Integrator of Ordinary Differential Equations System for Space Experiment Simulation
Atanas Marinov Atanassov
Different possible sources are discussed for enhancement of the calculation time when solving ordinary differential equations systems to forecast space objects' motion. This paper…
Integration of the Equation of the artificial Earth's Satellites Motion with Selection of Runge-Kutta-Fehlberg Schemes of Optimum Precision Order
Atanas Marinov Atanassov
An approach is treated for numerical integration of ordinary differential equations systems of the first order with choice of a computation scheme, ensuring the required local prec…
Manifolds which are Ivanov-Petrova or k-Stanilov
P. Gilkey, S. Nikcevic, V. Videv
We present some examples of curvature homogeneous pseudo-Riemannian manifolds which are k-spacelike Jordan Stanilov; their higher order curvature operator has constant Jordan norma…