Results 111 to 120 of about 137,800 (236)
Weighted Turán Theorems With Applications to Ramsey‐Turán Type of Problems
Journal of Graph Theory, EarlyView.ABSTRACT We study extensions of Turán Theorem in edge‐weighted settings. A particular case of interest is when constraints on the weight of an edge come from the order of the largest clique containing it. These problems are motivated by Ramsey‐Turán type problems.
József Balogh +2 more
wiley +1 more source
A Nordhaus–Gaddum Problem for the Spectral Gap of a Graph
Journal of Graph Theory, EarlyView.ABSTRACT Let G $G$ be a graph on n $n$ vertices, with complement G¯ $\bar{G}$. The spectral gap of the transition probability matrix of a random walk on G $G$ is used to estimate how fast the random walk becomes stationary. We prove that the larger spectral gap of G $G$ and G¯ $\bar{G}$ is Ω(1∕n) ${\rm{\Omega }}(1\unicode{x02215}n)$.
Sooyeong Kim, Neal Madras
wiley +1 more source
Complexity, 2018 We present a novel method, called graph sparse nonnegative matrix factorization, for dimensionality reduction. The affinity graph and sparse constraint are further taken into consideration in nonnegative matrix factorization and it is shown that the ...
Xiangguang Dai +2 more
doaj +1 more source
Adaptive Graph Regularization Discriminant Nonnegative Matrix Factorization for Data Representation
IEEE Access, 2019 Nonnegative matrix factorization, as a classical part-based representation method, has been widely used in pattern recognition, data mining and other fields.
Lin Zhang +3 more
doaj +1 more source
Small‐scale thermal habitat variability may not determine seagrass resilience to climate change
Limnology and Oceanography, EarlyView.Abstract Seagrass ecosystems are integral components of coastal marine environments, but they face global threats from climate change. The ability of seagrass to withstand these challenges depends on trait variation among individuals, which is influenced by genetic background and plasticity.
Giannina S. I. Hattich +7 more
wiley +1 more source
Complex & Intelligent SystemsCommunity detection is an important method to analyze the characteristics and structure of community networks, which can excavate the potential links between nodes and further discover subgroups from complex networks.
Zigang Chen +6 more
doaj +1 more source
Existence of a local strong solution to the beam–polymeric fluid interaction system
Mathematische Nachrichten, EarlyView.Abstract We construct a unique local strong solution to the finitely extensible nonlinear elastic (FENE) dumbbell model of Warner‐type for an incompressible polymer fluid (described by the Navier–Stokes–Fokker–Planck equations) interacting with a flexible elastic shell.
Dominic Breit, Prince Romeo Mensah
wiley +1 more source
IEEE Access, 2019 Nonnegative matrix factorization (NMF) is a powerful tool for hyperspectral unmixing (HU). This method factorizes a hyperspectral cube into constituent endmembers and their fractional abundances.
Li Sun +3 more
doaj +1 more source
Global and microlocal aspects of Dirac operators: Propagators and Hadamard states
Mathematische Nachrichten, EarlyView.Abstract We propose a geometric approach to construct the Cauchy evolution operator for the Lorentzian Dirac operator on Cauchy‐compact globally hyperbolic 4‐manifolds. We realize the Cauchy evolution operator as the sum of two invariantly defined oscillatory integrals—the positive and negative Dirac propagators—global in space and in time, with ...
Matteo Capoferri, Simone Murro
wiley +1 more source
A multilevel approach for nonnegative matrix factorization [PDF]
Nonnegative Matrix Factorization (NMF) is the problem of approximating a nonnegative matrix with the product of two low-rank nonnegative matrices and has been shown to be particularly useful in many applications, e.g., in text mining, image processing ...
GILLIS, Nicolas, GLINEUR, François
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