A circular-arc hypergraph H is a hypergraph admitting an arc ordering, that is, a circular ordering of the vertex set V (H) such that every hyperedge is an arc of consecutive vertices. An arc ordering is tight if, for any two hyperedges A and B such that ∅ 6 = A ⊆ B 6= V (H), the corresponding arcs share a common endpoint. We give sufficient conditions for H to have, up to reversing, a unique a...

A Helly circular-arc modelM = (C,A) is a circle C together with a Helly family A of arcs of C. If no arc is contained in any other, thenM is a proper Helly circular-arc model, if every arc has the same length, then M is a unit Helly circular-arc model, and if there are no two arcs covering the circle, thenM is a normal Helly circular-arc model. A Helly (resp. proper Helly, unit Helly, normal He...

Abstract: Clique graphs of several classes of graphs have been already characterized. Trees, interval graphs, chordal graphs, block graphs, clique-Helly graphs are some of them. However, no characterization of clique graphs of circular-arc graphs and some of their subclasses is known. In this paper, we present a characterization theorem of clique graphs of Helly circular-arc graphs and prove th...

indicates the location of metal implants. b) Auto-calibrated SENSE (RMSE = 1037). c) SENSE with single calibration (RMSE = 3364). The arrow indicates image artifacts. d) Autocalibrated ARC (RMSE=372). e) ARC recon using single calibration (RMSE = 383). f) ARC recon using two concatenated calibration data sets (RMSE = 364). Figure 3: a) Fast spin-echo image. b) Fully sampled MAVRIC image c)Under...

This paper studies peek arc consistency, a reasoning technique that extends the wellknown arc consistency technique for constraint satisfaction. In contrast to other more costly extensions of arc consistency that have been studied in the literature, peek arc consistency requires only linear space and quadratic time and can be parallelized in a straightforward way such that it runs in linear tim...

An arc in a tournament T with n ≥ 3 vertices is called pancyclic if it belongs to a cycle of length l for all 3 ≤ l ≤ n. We call a vertex u of T an out-arc pancyclic vertex of T if each out-arc of u is pancyclic in T . Yao, Guo and Zhang [Discrete Appl. Math. 99 (2000), 245–249] proved that every strong tournament contains at least one out-arc pancyclic vertex, and they gave an infinite class o...

This paper presents a new specification language called ARC. The language ARC is designed for specifying systems where communication plays a pivotal role. ARC takes simple message sequence charts as a starting point and extends them to allow the precise specification of complex communication behaviour. ARC includes the language COLD-K for specifying data and operations on data. The goal in desi...

A function is called arc-analytic if it is real analytic on each real analytic arc. In real analytic geometry there are many examples of arc-analytic functions that are not real analytic. Arc analytic functions appear while studying the arc-symmetric sets and the blow-analytic equivalence. In this paper we show that the non-analyticity locus of an arc-analytic function is arc-symmetric. We disc...

The dentate gyrus (DG) engages in sustained Arc transcription for at least 8 hours following behavioral induction, and this time course may be functionally coupled to the unique role of the DG in hippocampus-dependent learning and memory. The factors that regulate long-term DG Arc expression, however, remain poorly understood. Animals lacking Egr3 show less Arc expression following convulsive s...

Weakly s-arc transitive graphs are introduced and determined. A graph is said to be weakly s-arc transitive if its endomorphism monoid acts transitively on the set of s-arcs. The main results are: (1) A nonbipartite graph is weakly s-arc transitive if and only if it is s-arc transitive. (2) A tree with diameter d is weakly s-arc transitive for all 0 s d. (3) A bipartite graph with girth g = 2s ...