Linear-time algorithms for scattering number and Hamilton-connectivity of interval graphs.

We prove that for all inline image an interval graph is inline image-Hamilton-connected if and only if its scattering number is at most k. This complements a previously known fact that an interval graph has a nonnegative scattering number if and only if it contains a Hamilton cycle, as well as a characterization of interval graphs with positive scattering numbers in terms of the minimum size of a path cover. We also give an inline image time algorithm for computing the scattering number of an interval graph with n vertices and m edges, which improves the previously best-known inline image time bound for solving this problem. As a consequence of our two results, the maximum k for which an interval graph is k-Hamilton-connected can be computed in inline image time

A Survey of Best Monotone Degree Conditions for Graph Properties

We survey sufficient degree conditions, for a variety of graph properties, that are best possible in the same sense that Chvatal's well-known degree condition for hamiltonicity is best possible.Comment: 25 page

Stars and bunches in planar graphs. Part II: General planar graphs and colourings

Given a plane graph, a $k$-star at $u$ is a set of $k$ vertices with a common neighbour $u$; and a bunch is a maximal collection of paths of length at most two in the graph, such that all paths have the same end vertices and the edges of the paths form consecutive edges (\,in the natural order in the plane graph\,) around the two end vertices. We first prove a theorem on the structure of plane graphs in terms of stars and bunches. The result states that a plane graph contains a $(d-1)$-star centred at a vertex of degree $d\leq5$ and the sum of the degrees of the vertices in the star is bounded, or there exists a large bunch. \u

Stars and bunches in planar graphs. Part I: Triangulations

Given a plane graph, a $k$-star at $u$ is a set of $k$ vertices with a common neighbour $u$; and a bunch is a maximal collection of paths of length at most two in the graph, such that all paths have the same end vertices and the edges of the paths form consecutive edges (\,in the natural order in the plane graph\,) around the two end vertices. We prove a theorem on the structure of plane triangulations in terms of stars and bunches. The result states that a plane triangulation contains a $(d-1)$-star centred at a vertex of degree $d\leq5$ and the sum of the degrees of the vertices in the star is bounded, or there exists a large bunch. \u

On a Directed Tree Problem Motivated by a Newly Introduced Graph Product

In this paper we introduce and study a directed tree problem motivated by a new graph product that we have recently introduced and analysed in two conference contributions in the context of periodic real-time processes. While the two conference papers were focussing more on the applications, here we mainly deal with the graph theoretical and computational complexity issues. We show that the directed tree problem is NP-complete and present and compare several heuristics for this problem

List coloring in the absence of a linear forest.

The k-Coloring problem is to decide whether a graph can be colored with at most k colors such that no two adjacent vertices receive the same color. The Listk-Coloring problem requires in addition that every vertex u must receive a color from some given set L(u)⊆{1,…,k}. Let Pn denote the path on n vertices, and G+H and rH the disjoint union of two graphs G and H and r copies of H, respectively. For any two fixed integers k and r, we show that Listk-Coloring can be solved in polynomial time for graphs with no induced rP1+P5, hereby extending the result of Hoàng, Kamiński, Lozin, Sawada and Shu for graphs with no induced P5. Our result is tight; we prove that for any graph H that is a supergraph of P1+P5 with at least 5 edges, already List 5-Coloring is NP-complete for graphs with no induced H

Recency of immersion in L2 environment more important than L2 proficiency in speech segmentation

Speech segmentation is a language-specific skill: each language provides different cues for optimally segmenting the continuous speech stream into words. When exposed to a novel language, listeners have been shown to use those segmentation cues that they are familiar with from their native language (L1)

Simulating Spanish-English code-switching: El modelo está generating code-switches

Multilingual speakers are able to switch from one language to the other (“code-switch”) be- tween or within sentences. Because the under- lying cognitive mechanisms are not well un- derstood, in this study we use computational cognitive modeling to shed light on the pro- cess of code-switching. We employed the Bilingual Dual-path model, a Recurrent Neu- ral Network of bilingual sentence production (Tsoukala et al., 2017) and simulated sentence production in simultaneous Spanish-English bilinguals. Our first goal was to investigate whether the model would code-switch with- out being exposed to code-switched training input. The model indeed produced code- switches even without any exposure to such input and the patterns of code-switches are in line with earlier linguistic work (Poplack, 1980). The second goal of this study was to investigate an auxiliary phrase asymmetry that exists in Spanish-English code-switched pro- duction. Using this cognitive model, we ex- amined a possible cause for this asymmetry. To our knowledge, this is the first computa- tional cognitive model that aims to simulate code-switched sentence production

Fusion cuisine:A functional approach to interdisciplinary cooking in journalism studies

Journalism studies as an academic field is characterized by multidisciplinarity. Focusing on one object of study, journalism and the news, it established itself by integrating and synthesizing approaches from established disciplines – a tendency that lives on today. This constant gaze to the outside for conceptual inspiration and methodological tools lends itself to a journalism studies that is a fusion cuisine of media, communication, and related scholarship. However, what happens when this object becomes as fragmented and multifaceted as the ways we study it? This essay addresses the challenge of multiplicity in journalism studies by introducing an audience-centred, functional approach to scholarship. We argue this approach encourages the creative intellectual advancements afforded by interdisciplinary experimental cooking while respecting the classical intellectual questions that helped define the culinary tradition of journalism studies in the first place. In so doing, we offer a recipe for journalism studies fusion cooking that: (1) considers technological change (audiences’ diets), (2) analyses institutional change (audiences’ supermarket of information), and (3) evaluates journalism’s societal and democratic impact (audiences’ cuisines and health)