Search

This paper presents a probability-based multi-measure feature matching method in map conflation. Feature matching is used to determine the corresponding features in different datasets that represent analogous entities in the real world. In the proposed method, a total matching probability is computed by the weighted average of multiple measures, including positional measure, shape measure, directional measure and topological measure. The matching strategies for point features, linear features and areal features are also provided. The proposed method is implemented in a prototype for matching features from two different data sources, and is compared with traditional methods. The results demonstrate not only the practicability of using the proposed method to resolve feature matching issues in map conflation, but also its advantages compared with traditional methods in terms of matching effects. [ABSTRACT FROM AUTHOR]

Let G be a connected graph. A spanning tree T of G is a tree t-spanner if the distance between any two vertices in T is at most t times their distance in G. If their distances in T and G differ by at most t, then T is an additive tree t-spanner of G. In this paper, we show that any permutation graph has an additive tree 2-spanner, and it can be found in O(n) time sequentially or in O(log n) time with O(n/log n) processors on the EREW PRAM computational model by using a previously published algorithm for finding a tree 3-spanner of a permutation graph. [ABSTRACT FROM AUTHOR]

In the present paper, we derive various families of linear, mixed multilateral and multilinear generating functions for a class of polynomials in two variables. Some further results of the above types are also discussed. [ABSTRACT FROM AUTHOR]

The article provides two short and direct proofs of J. S. Pym's result in his 1969 paper "The linking of sets in graphs," regarding the Cantor-Bernstein theorem for paths in graphs. Both proofs are elementary, and they can be examined independently. The first proof employs transfinite induction. This proof starts from the first set of paths which is then transformed step by step into the wanted bijective set by integrating path segments from the second set. The choices made during this inductive process have been made arbitrary. For the second proof, these choices are made explicitly.

The article explores the so-called λ-permutations shown by Steven Krantz and Jeffery McNeal in their paper "Creating more convergent series." They specified that a permutation σ of the positive integers is a λ-permutation if it has two characteristics. The first property is that for every convergent series, the summation of ak from k =1 to infinity, the summation of aσ(k) from k =1 to infinity also converges. The second property is that there is at least one divergent series which is the summation of ak from k =1 to infinity such that the summation of aσ(k) from k =1 to infinity converges.

The main result of this paper is a graph-theoretic necessary and sufficient condition, for a given set of transvections in SL(n, K) (n > 2 and K a finite field of characteristic not 2 or 3), to generate a group isomorphic to SL(m, L), for some m and some subfield L of K. [ABSTRACT FROM AUTHOR]

Let n be an integer greater than 1. A group G is said to be n-rewritable (or a Q n -group) if for every n elements x 1 , x 2 ,...,x n in G there exist distinct permutations s and t in S n such that x s(1) x s (2) ··· x s(n) = x t(1) x t(2) ··· x t(n) . In this paper, we characterize all 3-rewritable nilpotent 2-groups of class 2. Also we have found a bound for the nilpotency class of certain nilpotent 3-rewritable groups, and have shown that 3-rewritable groups satisfy a certain law. [ABSTRACT FROM AUTHOR]

Let G be an edge-coloured graph. We show in this paper that it is NP-hard to find the minimum number of vertex disjoint monochromatic trees which cover the vertices of the graph G . We also show that there is no constant factor approximation algorithm for the problem unless P = NP. The same results hold for the problem of finding the minimum number of vertex disjoint monochromatic cycles (paths, respectively) which cover the vertices of the graph. [ABSTRACT FROM AUTHOR]

In this paper we study the resolution of a facet ideal associated with a special class of simplicial complexes introduced by Faridi. These simplicial complexes are called trees, and are a generalization (to higher dimensions) of the concept of a tree in graph theory. We show that the Koszul homology of the facet ideal I of a tree is generated by the homology classes of monomial cycles, determine the projective dimension and the regularity of I if the tree is 1-dimensional, show that the graded Betti numbers of I satisfy an alternating sum property if the tree is connected in codimension 1, and classify all trees whose facet ideal has a linear resolution. [ABSTRACT FROM AUTHOR]