Join is the most expensive and the frequent operation in database. Significant numbers of join queries are executed in the interactive applications. In interactive applications the first few thousand results need to be produced without any delay. The current join algorithms are mainly based on hash join or sort merge join which is less suitable for interactive applications because some pre-work...

The cyclicity of a hypergraph is an e ciently computable integer that extends the notion of the cyclomatic number of a graph The formula for the cyclicity is suggested by the join invariant of an acyclic hypergraph which is the multiset of all joining sets in any of its join trees Once we gure out how the multiplicity of a joining set depends on the structure of the acyclic hypergraph we de ne ...

Baer [1] observed that modular lattices of finite length (for example subgroup lattices of abelian groups) can be conceived as subspace lattices of a projective geometry structure on an ordered point set; the set of join irreducibles which in this case are the cyclic subgroups of prime power order. That modular lattices of finite length can be recaptured from the order on the points and, in add...

Hyperplane arrangements and descent algebras Franco V Saliola saliola-DesAlgLectureNotes.pdf version of 10 January 2006 Errata and addenda by Darij Grinberg I will refer to the results appearing in the article " A Hyperplane arrangements and descent algebras " by the numbers under which they appear in this article. 6. Errata • Various places (for example, §2.1): You use the notations ⊆ and ⊂ sy...

Abstract In this paper, we construct the cut‐and‐join operator description for generating functions of all intersection numbers , and classes on moduli spaces . The operators define an algebraic version topological recursion. This recursion allows us to compute these recursively. For specific values parameters, describe volumes (super) hyperbolic Riemann surfaces with geodesic boundaries, which...

Given a manifold X , the set of manifold structures on X × ∆ relative to the boundary can be viewed as the k-th homotopy group of a space S̃s(X). This space is called the block structure space of X . Free involutions on spheres are in one-to-one correspondence with manifold structures on real projective spaces. We generalize Wall’s join construction for free involutions on spheres to define a fu...

Given a number of Extended Chebyshev (EC) spaces on adjacent intervals, all of the same dimension, we join them via convenient connection matrices without increasing the dimension. The global space is called a Piecewise Extended Chebyshev (PEC) Space. In such a space one can count the total number of zeroes of any non-zero element, exactly as in each ECsection-space. When this number is bounded...

'Space and place are central to the strategies and meaning of protest’ (p. xi) reads the opening sentence of Katrina Navickas's latest study, Protest and the Politics of Space and Place 1789–1848. Written, in part, as a response to the 'spatial turn' in History, Navickas makes a cogent and persuasive argument for attending to the importance of the particularities of 'place' rather than the abst...