Fan Chung and Ron Graham (J. Combin. Theory Ser. B 65 (1995), 273-290) introduced the cover polynomial for a directed graph and showed that it was connected with classical rook theory. M. Dworkin (J. Combin. Theory Ser. B 71 (1997), 17-53) showed that the cover polynomial naturally factors for directed graphs associated with Ferrers boards. The authors (Adv. Appl. Math. 27 (2001), 438-481) deve...

Two geostatistical methods for history matching are presented. Both rely on the sequential simulation principle for generating geologically sound realizations. The first method relies on perturbing the sequential simulation through the perturbation of the conditional distribution models; the second method relies on the perturbation of random numbers. We show that both approaches are general in ...

The graph is an essential data structure for representing relational information. When graphs are used to represent objects, comparing objects amounts to graph matching. Inexact graph matching is the process of finding the best possible matching between two graphs when exact matching is impossible. In this paper, we propose a new algorithm for the inexact matching problem. The new algorithm dec...

The δ-approximate string matching problem, recently introduced in connection with applications to music retrieval, is a generalization of the exact string matching problem for alphabets of integer numbers. In the δ-approximate variant, (exact) matching between any pair of symbols/integers a and b is replaced by the notion of δ-matching =δ, where a =δ b if and only if |a− b| ≤ δ for a given valu...

In pattern matching with character classes the goal is to find all occurrences of a pattern of length m in a text of length n, where each pattern position consists of an allowed set of characters from a finite alphabet Σ. We present an FFT-based algorithm that uses a novel prime-numbers encoding scheme, which is log n/ log m times faster than the fastest extant approaches, which are based on bo...

language is a system and every system has rules that govern the structure of its vocabulary. the rules of the arabic language are based on the vowels that consistent with the meanings used in the context represent the words' position. there are some basic rules in addition to vowels which are mostly seen in the written texts. one of these rules is the matching rule that refers to the condi...

background: one of the challenges of pet/mri combined systems is to derive an attenuation map to correct the pet image. for that, the pseudo-ct image could be used to correct the attenuation. until now, most existing scientific researches construct this pseudo-ct image using the registration techniques. however, these techniques suffer from the local minima of the non-rigid deformation energy f...

the purpose of the matching interdiction problem in a weighted graph is to findtwo vertices such that the weight of the maximum matching in the graph withoutthese vertices is minimized. an approximate solution for this problem has beenpresented. in this paper, we consider dendrimers as graphs such that the weightsof edges are the bond lengths. we obtain the maximum matching in some types ofdend...

For the many-to-one matching model in which firms have substitutable and quota q−separable preferences over subsets of workers we show that the workers-optimal stable mechanism is group strategy-proof for the workers. Therefore, in centralized markets like entry-level professional labor markets if the proposed matching is the workers-optimal stable matching then, no group of workers can never b...