Results 111 to 120 of about 62,209 (271)

On Oriented Colourings of Graphs on Surfaces

Journal of Graph Theory, EarlyView.
ABSTRACT For an oriented graph G $G$, the least number of colours required to oriented colour G $G$ is called the oriented chromatic number of G $G$ and denoted χ o ( G ) ${\chi }_{o}(G)$. For a non‐negative integer g $g$ let χ o ( g ) ${\chi }_{o}(g)$ be the least integer such that χ o ( G ) ≤ χ o ( g ) ${\chi }_{o}(G)\le \unicode{x0200A}{\chi }_{o}(g)
Alexander Clow
wiley   +1 more source

Chordal Graphs are Fully Orientable [PDF]

, 2012
Suppose that D is an acyclic orientation of a graph G. An arc of D is called dependent if its reversal creates a directed cycle. Let m and M denote the minimum and the maximum of the number of dependent arcs over all acyclic orientations of G.
Lai, Hsin-Hao, Lih, Ko-Wei
core  

Fractional Balanced Chromatic Number and Arboricity of Planar (Signed) Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT A balanced ( p , q ) $(p,q)$‐coloring of a signed graph ( G , σ ) $(G,\sigma )$ is an assignment of q $q$ colors to each vertex of G $G$ from a platter of p $p$ colors, such that each color class induces a balanced set (a set that does not induce a negative cycle).
Reza Naserasr, Lan Anh Pham, Cyril Pujol, Huan Zhou   +3 more
wiley   +1 more source

Orientations of Graphs With at Most One Directed Path Between Every Pair of Vertices

Journal of Graph Theory, EarlyView.
ABSTRACT Given a graph G $G$, we say that an orientation D $D$ of G $G$ is a KT orientation if, for all u , v ∈ V ( D ) $u,v\in V(D)$, there is at most one directed path (in any direction) between u $u$ and v $v$. Graphs that admit such orientations have been used to construct graphs with large chromatic number and small clique number that served as ...
Barbora Dohnalová, Jiří Kalvoda, Gaurav Kucheriya, Sophie Spirkl   +3 more
wiley   +1 more source

Scheduling early primary care follow‐up after pneumonia: A retrospective target trial emulation in five hospitals

Journal of Hospital Medicine, EarlyView.
Abstract Background Current guidelines make no recommendations on discharge interventions or scheduling outpatient follow‐up after hospitlization for commnity‐acquired pneumonia (CAP). Objectives To assess the impact of scheduling early primary care follow‐up prior to discharge home among survivors of hypoxemic CAP hospitalizations.
Andrew J. Davis, Stephanie P. Taylor, Catherine L. Hough, Mari Armstrong‐Hough, Li Yan, Catherine K. Ettman, Katy Sadowski, Khyzer B. Aziz, Patrick G. Lyons, Katrina E. Hauschildt, Marc Kowalkowski, Eliana M. Perrin, Theodore J. Iwashyna   +12 more
wiley   +1 more source

Complexity of factors affecting bobolink population dynamics communicated with directed acyclic graphs

Wildlife Society Bulletin, 2017
North American grassland birds experienced steeper, more consistent, and widespread declines than other avian guilds in the past quarter century. Despite the surge of research into their ecology and conservation, there remains considerable uncertainty ...
Danielle M. Ethier, Thomas D. Nudds
doaj   +1 more source

Enhancing Study Design and Analysis of MR Imaging Markers Through Measurement Error Modeling

Journal of Magnetic Resonance Imaging, EarlyView.
ABSTRACT Background Measurement error in imaging reduces statistical power and potentially biases parameter estimation, compromising study reliability. Purpose To introduce a dual data collection design (reliability and main datasets) to quantify measurement error and apply regression calibration to correct error‐prone imaging markers, thereby ...
Xiaofeng Wang, Walter Zhao, Yifan Wang, Deborah H. Kwon, Ting‐Yu Su, Nancy A. Obuchowski, Mark A. Griswold, Zhong Irene Wang, Dan Ma   +8 more
wiley   +1 more source

A typology of four notions of confounding in epidemiology

Journal of Epidemiology, 2017
Confounding is a major concern in epidemiology. Despite its significance, the different notions of confounding have not been fully appreciated in the literature, leading to confusion of causal concepts in epidemiology.
Etsuji Suzuki
doaj   +1 more source

Treemaps for Directed Acyclic Graphs [PDF]

, 2008
Gene Ontology information related to the biological role of genes is organized in a hierarchical manner that can be represented by a directed acyclic graph (DAG). Treemaps graphically represent hierarchical information via a two-dimensional rectangular map. They efficiently display large trees in limited screen space.
Vassilis Tsiaras, Sofia Triantafilou, Ioannis G. Tollis   +2 more
openaire   +1 more source

Functional tooth unit, periodontal status, and association with weight change in older adults

Journal of Periodontology, EarlyView.
Abstract Background Literature reports that having fewer teeth is associated with reduced chewing capacity, which in turn may lead to weight changes due to diminished oral functionality. This study aims to assess the association between functional tooth units (FTU) and periodontal status and weight change among older adults participating in the Health,
Mariana S. Muñoz, Natália M. Pola, Juliana B. Hilgert, Fernando N. Hugo, Roberto P. Pimentel, Eleanor M. Simonsick, Francisco W. M. G. Muniz   +6 more
wiley   +1 more source