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Перегляд Algebra and Discrete Mathematics за датою випуску

Репозиторій DSpace/Manakin

Перегляд Algebra and Discrete Mathematics за датою випуску

Сортувати за: Порядок: Результатів:

  • Virtual endomorphisms of groups 
    Nekrashevych, V. (Algebra and Discrete Mathematics, 2002)
    Dedicated to V. V. Kirichenko on the occasion of his 60th birthday
  • Metrizable ball structures 
    Protasov, I.V. (Algebra and Discrete Mathematics, 2002)
    A ball structure is a triple (X, P, B), where X, P are nonempty sets and, for any x ∈ X, α ∈ P, B(x, α) is a subset of X, x ∈ B(x, α), which is called a ball of radius α around x. We characterize up to isomorphism the ...
  • On groups of finite normal rank 
    Dashkova, O.Yu. (Algebra and Discrete Mathematics, 2002)
    In this article the investigation of groups of finite normal rank is continued. The finiteness of normal rank of nonabelian p-group G is proved where G has a normal elementary abelian p-subgroup A for which quotient group ...
  • On dispersing representations of quivers and their connection with representations of bundles of semichains 
    Bondarenko, V.M. (Algebra and Discrete Mathematics, 2002)
    In the paper we discuss the notion of “dispersing representation of a quiver” and give, in a natural special case, a criterion for the problem of classifying such representations to be tame. In proving the criterion we ...
  • Bounds for graphs of given girth and generalized polygons 
    Benkherouf, L.; Ustimenko, V. (Algebra and Discrete Mathematics, 2002)
    In this paper we present a bound for bipartite graphs with average bidegrees η and ξ satisfying the inequality η ≥ ξ α, α ≥ 1. This bound turns out to be the sharpest existing bound. Sizes of known families of finite ...
  • On the finite state automorphism group of a rooted tree 
    Lavrenyuk, Y. (Algebra and Discrete Mathematics, 2002)
    The normalizer of the finite state automorphism group of a rooted homogeneous tree in the full automorphism group of this tree was investigated. General form of elements in the normalizer was obtained and countability ...
  • Radical theory in BCH-algebras 
    Dudek, W.A.; Young Bae Jun (Algebra and Discrete Mathematics, 2002)
    The notion of k-nil radical in BCH-algebras is defined, and related properties are investigated.
  • Tiled orders over discrete valuation rings, finite Markov chains and partially ordered sets. I 
    Chernousova, Zh.T.; Dokuchaev, M.A.; Khibina, M.A.; Kirichenko, V.V.; Miroshnichenko, S.G.; Zhuravlev, V.N. (Algebra and Discrete Mathematics, 2002)
    We prove that the quiver of tiled order over a discrete valuation ring is strongly connected and simply laced. With such quiver we associate a finite ergodic Markov chain. We introduce the notion of the index in A of a ...
  • N – real fields 
    Feigelstock, S. (Algebra and Discrete Mathematics, 2003)
    A field F is n-real if −1 is not the sum of n squares in F. It is shown that a field F is m-real if and only if rank (AAt ) = rank (A) for every n × m matrix A with entries from F. An n-real field F is n-real closed ...
  • On subgroups of saturated or totally bounded paratopological groups 
    Banakh, T.; Ravsky, S. (Algebra and Discrete Mathematics, 2003)
    A paratopological group G is saturated if the inverse U ⁻¹ of each non-empty set U ⊂ G has non-empty interior. It is shown that a [first-countable] paratopological group H is a closed subgroup of a saturated (totally ...
  • An additive divisor problem in Z[i] 
    Savasrtu, O.V.; Varbanets, P.D. (Algebra and Discrete Mathematics, 2003)
  • Binary coronas of balleans 
    Protasov, I.V. (Algebra and Discrete Mathematics, 2003)
    A ballean B is a set X endowed with some family of subsets of X which are called the balls. We postulate the properties of the family of balls in such a way that a ballean can be considered as an asymptotic counterpart ...
  • Multi-algebras from the viewpoint of algebraic logic 
    Cırulis, J. (Algebra and Discrete Mathematics, 2003)
    Where U is a structure for a first-order language L ≈ with equality ≈, a standard construction associates with every formula f of L ≈ the set kfk of those assignments which fulfill f in U. These sets make up a (cylindric ...
  • H- and R-cross-sections of the full finite semigroup Tn 
    Pyekhtyeryev, V. (Algebra and Discrete Mathematics, 2003)
    All H− and R− cross-sections of the full finite semigroup Tn of all transformations of the set N = {1, 2, . . . , n} are described.
  • On equivalence of some subcategories of modules in Morita contexts 
    Kashu, A.I. (Algebra and Discrete Mathematics, 2003)
  • Ramseyan variations on symmetric subsequences 
    Verbitsky, O. (Algebra and Discrete Mathematics, 2003)
    A theorem of Dekking in the combinatorics of words implies that there exists an injective order-preserving transformation f : {0, 1, . . . , n} → {0, 1, . . . , 2n} with the restriction f(i + 1) ≤ f(i) + 2 such that for ...
  • On check character systems over quasigroups and loops 
    Belyavskaya, G.B. (Algebra and Discrete Mathematics, 2003)
    In this article we study check character systems that is error detecting codes, which arise by appending a check digit an to every word a₁a₂...an₋₁ : a₁a₂...an₋₁ → a₁a₂...an₋₁an with the check formula (...((a₁ · δa₂) · δ ...
  • An algebraic version of the Strong Black Box 
    Göbel, R.; Wallutis, S.L. (Algebra and Discrete Mathematics, 2003)
    Various versions of the prediction principle called the “Black Box” are known. One of the strongest versions can be found in [EM]. There it is formulated and proven in a model theoretic way. In order to apply it to ...
  • Green’s relations on the seminearring of full hypersubstitutions of type (n) 
    Changphas, Th.; Denecke, K. (Algebra and Discrete Mathematics, 2003)
    Hypersubstitutions are mappings which are used to define hyperidentities and solid varieties. In this paper we will show that the set of all hypersubstitutions of a given type forms a seminearring. We will give a full ...
  • On intersections of normal subgroups in free groups 
    Kulikova, O.V. (Algebra and Discrete Mathematics, 2003)
    Let N₁ (respectively N₂) be a normal closure of a set R₁ = {ui} (respectively R₂ = {vj}) of cyclically reduced words of the free group F(A). In the paper we consider geometric conditions on R₁ and R₂ for N₁ ∩ N₂ = [N₁, ...

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