Let E n = {[τ ]a = (τ (a1) 1 , . . . , τ (an) n )|τ ∈ Sn, 1 ≤ ai ≤ r} be the set of all signed permutations on the symbols 1, 2, . . . , n with signs 1, 2, . . . , r. We prove, for every 2-letter signed pattern [τ ]a, that the number of [τ ]a-avoiding signed permutations in E n is given by the formula n ∑ j=0 j!(r−1) ( n j 2 . Also we prove that there are only one Wilf class for r = 1, four Wil...

Recently, a mechanism for relaxing a large cosmological constant (CC) has been proposed [1], which transforms any initial vacuum energy density of arbitrary sign and magnitude into a harmless quantity without fine-tuning. The setup is implemented in the ΛXCDM framework, and it yields a reasonable cosmological background evolution similar to the ΛCDM model with a fine-tuned CC. In this work we a...

We report observations of SMC X-1 in three new high-intensity states with ROSAT HRI in December 1995, May 1997, and March 1998 in which pulsations with a period of 0.70769 (± 0.00006) s, 0.70706 (± 0.00001) s, and 0.706707 (± 0.00001) s respectively were detected. Combining the pulse periods from observations with ROSAT PSPC in high-intensity states in October 1991 and March 1998, respectively,...

For learning purposes, representations of real world objects can be built by using the concept of dissimilarity. In such a case, an object is characterized in a relative way, i.e. by its dissimilarities to a set of the selected prototypes. Such dissimilarity representations are found to be more practical for some pattern recognition problems. When experts cannot decide for a single dissimilarit...

When learners encode sequential patterns and generalize their knowledge to novel instances, are they relying on abstract or stimulus-specific representations? Artificial grammar learning (AGL) experiments showing transfer of learning from one stimulus set to another has encouraged the view that learning is mediated by abstract representations that are independent of the sense modality or percep...

Consonant liaison at word boundaries in French is the result of a complex interplay of grammatical and extragrammatical factors. In this paper we offer a descriptive overview of syntactic factors influencing liaison. We provide a detailed analysis in the framework of HPSG, that integrates the morphophonological and syntactic conditions governing this feature of French grammar. Although we do no...

Introduction. Group representations occupy a sort of middle ground between abstract groups and transformation groups, i.e., groups acting in concrete ways as permutations of sets, homeomorphisms of topological spaces, diffeomorphisms of manifolds, etc. The requirement that the elements of a group act as linear operators on a vector space limits somewhat the complexity of the action without sacr...