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A Note on Null Models: Justifying the Methodology
Ecology, 2002The use of random, or null, models to determine whether species co-occurrences differ from chance expectations is an established technique in community ecology. Several methods have been used to draw conclusions regarding species co-occurrence patterns. We compared a sequential method derived previously with a recently proposed new method.
Bryan Manly, James G. Sanderson
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Faddeev null-plane model of the nucleon
Physical Review C, 1995The nucleon is formulated as a relativistic system of three constituent quarks interacting via a zero-range two-body force in the null plane. The covariance of the null-plane Faddeev-like equation under kinematical front-form boosts is discussed. The nucleon wave function is obtained from the numerical solution of the Faddeev equation in the null plane.
, de Araújo WR +2 more
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THE SCHWINGER MODEL ON THE NULL-PLANE
International Journal of Modern Physics E, 2007We study the Schwinger Model on the null-plane using the Dirac method for constrained systems. The fermion field is analyzed using the natural null-plane projections coming from the γ-algebra and it is shown that the fermionic sector of the Schwinger Model has only second class constraints.
Casana, R. +2 more
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Null Controllability in a Heat–Solid Structure Model
Applied Mathematics and Optimization, 2008zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Vanninathan, Muthusamy +1 more
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P Values for Composite Null Models
Journal of the American Statistical Association, 2000Abstract The problem of investigating compatibility of an assumed model with the data is investigated in the situation when the assumed model has unknown parameters. The most frequently used measures of compatibility are p values, based on statistics T for which large values are deemed to indicate incompatibility of the data and the model.
M. J. Bayarri, James O. Berger
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1994
Abstract The problem with models in phylogenetic inference is one of regress or circularity. Sound models demand either some knowledge of phylogeny, or assumptions about it. If knowledge is claimed, how was that knowledge gained? If assumptions are held to be merely provisional or approximate, how will they be tested by phylogenies that ...
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Abstract The problem with models in phylogenetic inference is one of regress or circularity. Sound models demand either some knowledge of phylogeny, or assumptions about it. If knowledge is claimed, how was that knowledge gained? If assumptions are held to be merely provisional or approximate, how will they be tested by phylogenies that ...
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Null Models in Cluster Validation
1996A brief overview is given of the problem of validation in classification studies. Attention is concentrated on the specification of appropriate null models for data, with respect to which one may assess some cluster structure that has been obtained as the output of a clustering algorithm.
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A Null Model for Null Models in Biogeography
2014ROBERT K. COLWELL, DAVID W. WINKLER
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20. A Null Model for Null Models in Biogeography
1984Robert K. Colwell, David W. Winkler
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