plan irregularity causes local damages being concentrated in the irregular buildings. progressive collapse is also the collapse of a large portion or whole building due to the local damages in the structure. the effect of irregularity on the progressive collapse potential of the buildings is investigated in this study. this is carried out by progressive collapse evaluation of the asymmetric mid...

The Honeycomb toroidal graph is a highly symmetric, vertex-transitive, bipartite graph which has been investigated for certain properties including pan-cyclicity and Hamilton laceability. The main focus of this project was to construct generalised methods for finding Hamilton paths and thus provide a proof of Hamilton laceability for this graph. The resulting proof was successful for a subset o...

Let Γ be a G-symmetric graph, and let B be a nontrivial G-invariant partition of the vertex set of Γ . This paper aims to characterize (Γ ,G) under the conditions that the quotient graph ΓB is (G, 2)-arc transitive and the induced subgraph between two adjacent blocks is 2 · K2 or K2,2. The results answer two questions about the relationship between Γ and ΓB for this class of graphs. c © 2007 El...

OWL is a recommended language for publishing and sharing ontologies on the Semantic Web. To manage the ontologies, several OWL data management systems have been proposed. However, the existing systems have limitations of the scalability and the reasoning. In this paper, we propose an OWL data management system, ONTOMS, which stores OWL data into class based relations, performs complete inverseO...

Here we solve a number of major open problems concerning computational properties of products and commutators of two ‘transitive’ (but not ‘symmetric’) standard modal logics (such as, e.g., K4, S4, S4.1, Grz, or GL) by showing that all of them are undecidable and lack the (abstract) finite model property. Some of these products turn out to be even not recursively enumerable and some commutators...

In this paper we generalize some classical factorizations of a fuzzy relation into a symmetric component (indifference) and an asymmetric and regular component (regular fuzzy strict preference). From the above notions, we establish two properties of any regular fuzzy strict preference of a max-∗-transitive fuzzy relation, which are then used to obtain new fuzzy versions of Gibbard’s oligarchy t...

Weak orders, i.e. reflexive, transitive, and complete binary relations, are among the most fundamental concepts in preference modeling. It is wellknown that weak orders are nothing else but linear orders of equivalence classes, where the corresponding equivalence relation is the symmetric kernel of the weak order. If the underlying set of alternatives X is finite, a weak order can be represente...

 After the classification of the flag-transitive linear spaces, the attention has been turned to line-transitive linear spaces. In this article, we present a partial classification of the finite linear spaces $mathcal S$ on which an almost simple group $G$ with the socle $G_2(q)$ acts line-transitively.

We study rough approximations based on indiscernibility relations which are not necessarily reflexive, symmetric or transitive. For this, we define in a lattice-theoretical setting two maps which mimic the rough approximation operators and note that this setting is suitable also for other operators based on binary relations. Properties of the ordered sets of the upper and the lower approximatio...

Block-transitive Steiner t-designs form a central part of the study of highly symmetric combinatorial configurations at the interface of several disciplines, including group theory, geometry, combinatorics, coding and information theory, and cryptography. The main result of the paper settles an important open question: There exist no non-trivial examples with t = 7 (or larger). The proof is bas...