Institutul de Matematică şi Informatică "Vladimir Andrunachievici"
Universitatea de Stat din MoldovaRO EN
β-acyclic schemes of databases. (Romanian)
Authors: Cotelea V., Ceban Ia.
Abstract
Four types of cycle on hypergraph are examined: $\beta$-cycle, week $\beta$-cycle, Graham cycle, independent cycle. It is shown that between these types of cycle exists the following relations: $\beta$-cycle $\Rightarrow$ week $\beta$-cycle $\Rightarrow$ Graham cycle $\Rightarrow$ independent cycle. Several necessary and sufficient conditions for database schemes to be $\beta$-acyclic are exposed.Institutul de Matematică Academia de Ştiinţe a Moldovei
str. Academiei 5, MD-2028 Chişinău, Moldova
str. Academiei 5, MD-2028 Chişinău, Moldova
Contents
- Approximate solution of singular integral equations with the help of series with respect to Faber-Laurent polynomials. (Russian)
- Global attractors of infinite-dimensional dynamical systems. I. (Russian)
- β-acyclic schemes of databases. (Romanian)
- Methods of derivation of semi-minor and pseudo-minor groups of $W$-symmetry. (Russian)
- On primitive solvable permutation groups with commutative stabilizer of a point. II. (Russian)
- Finite generated subalgebras of free CHQ-algebra. (English)
- Submodules determined by cohereditary radicals. (English)
- On strongly regular near-rings. (English)
- Impact of viscoelastic rod upon an obstacle. (Russian)
- On the property of a right ideal of a ring to be two-sided. (Russian)
- Energy saving in agro-food complex. (English)
- Impact of an elastic rod of finite length upon a compliant obstacle. II. (Russian)
- On automorphism groups of left-distributive quasigroups. (Russian)
- Torsion theories and subcategories of divisible modules. (English)
- Generating functions for comitants of differential systems. (Russian)
