Now showing items 42-61 of 72

  • Lengths of words in transformation semigroups generated by digraphs 

    Cameron, P. J.; Castillo-Ramirez, A.; Gadouleau, M.; Mitchell, J. D. (2017-02) - Journal article
    Given a simple digraph D on n vertices (with n≥2), there is a natural construction of a semigroup of transformations ⟨D⟩. For any edge (a, b) of D, let a→b be the idempotent of rank n−1 mapping a to b and fixing all vertices ...
  • Mixture models for distance sampling detection functions 

    Miller, David Lawrence; Thomas, Len (2015-03-20) - Journal article
    We present a new class of models for the detection function in distance sampling surveys of wildlife populations, based on finite mixtures of simple parametric key functions such as the half-normal. The models share many ...
  • Modeling the aggregated exposure and responses of bowhead whales Balaena mysticetus to multiple sources of anthropogenic underwater sound 

    Ellison, William T.; Racca, Roberto; Clark, Christopher W.; Streever, Bill; Frankel, Adam S.; Fleishman, Erica; Angliss, Robyn; Berger, Joel; Ketten, Darlene; Guerra, Melania; Leu, Matthias; McKenna, Megan; Sformo, Todd; Southall, Brandon; Suydam, Robert; Thomas, Len (2016-05-02) - Journal article
    Potential responses of marine mammals to anthropogenic underwater sound are usually assessed by researchers and regulators on the basis of exposure to a single, relatively loud sound source. However, marine mammals typically ...
  • Modelling group dynamic animal movement 

    Langrock, Roland; Hopcraft, Grant; Blackwell, Paul; Goodall, Victoria; King, Ruth; Niu, Mu; Patterson, Toby; Pedersen, Martin; Skarin, Anna; Schick, Robert Schilling (2014-02) - Journal article
    1). Group dynamics are a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognized, particularly in order to differentiate the role ...
  • Most primitive groups are full automorphism groups of edge-transitive hypergraphs 

    Babai, Laszlo; Cameron, Peter Jephson (2015-01-01) - Journal article
    We prove that, for a primitive permutation group G acting on a set of size n, other than the alternating group, the probability that Aut(X,YG) = G for a random subset Y of X, tends to 1 as n tends to infinity. So the ...
  • Most switching classes with primitive automorphism groups contain graphs with trivial groups 

    Cameron, Peter Jephson; Spiga, Pablo (2015-06) - Journal article
    The operation of switching a graph Gamma with respect to a subset X of the vertex set interchanges edges and non-edges between X and its complement, leaving the rest of the graph unchanged. This is an equivalence relation ...
  • Nested row-column designs for near-factorial experiments with two treatment factors and one control treatment 

    Bailey, Rosemary Anne; Lacka, Agnieszka (2015-10) - Journal article
    This paper presents some methods of designing experiments in a block design with nested rows and columns. The treatments consist of all combinations of levels of two treatment factors, with an additional control treatment.
  • On optimality and construction of circular repeated-measurements designs 

    Bailey, Rosemary Anne; Cameron, Peter Jephson; Filipiak, Katarzyna; Kunert, Joachim; Markiewicz, Augustyn (2017-01) - Journal article
    The aim of this paper is to characterize and construct universally optimal designs among the class of circular repeated-measurements designs when the parameters do not permit balance for carry-over effects. It is shown ...
  • Optimal cross-over designs for full interaction models 

    Bailey, Rosemary Anne; Druilhet, Pierre (2014-11) - Journal article
    We consider repeated measurement designs when a residual or carry-over effect may be present in at most one later period. Since assuming an additive model may be unrealistic for some applications and leads to biased ...
  • Passive acoustic monitoring of beaked whale densities in the Gulf of Mexico 

    Hildebrand, John; Baumann-Pickering, Simone; Frasier, Kaitlin; Trickey, Jennifer; Merkens, Karlina; Wiggins, Sean; McDonald, Mark; Garrison, Lance; Harris, Danielle; Marques, Tiago A.; Thomas, Len (2015-11-12) - Journal article
    Beaked whales are deep diving elusive animals, difficult to census with conventional visual surveys. Methods are presented for the density estimation of beaked whales, using passive acoustic monitoring data collected at ...
  • Passive acoustic monitoring of the decline of Mexico's critically endangered vaquita 

    Jaramillo-Legorreta, Armando; Cardenas-Hinojosa, Gustavo; Nieto-Garcia, Edwyna; Rojas-Bracho, Lorenzo; Hoef, Jay Ver; Moore, Jeffrey; Tregenza, Nicholas; Barlow, Jay; Gerrodette, Tim; Thomas, Len; Taylor, Barbara (2017-02) - Journal article
    The vaquita (Phocoena sinus) is the world's most endangered marine mammal with ≈245 individuals remaining in 2008. This species of porpoise is endemic to the northern Gulf of California, Mexico, and has historically suffered ...
  • Permutation groups and transformation semigroups : results and problems 

    Araujo, Joao; Cameron, Peter Jephson (Cambridge University Press, 2015-10) - Book item
    J.M. Howie, the influential St Andrews semigroupist, claimed that we value an area of pure mathematics to the extent that (a) it gives rise to arguments that are deep and elegant, and (b) it has interesting interconnections ...
  • PReMiuM : an R package for profile regression mixture models using Dirichlet processes 

    Liverani, Silvia; Hastie, David; Azizi, Lamiae; Papathomas, Michail; Richardson, Sylvia (2015-03-20) - Journal article
    PReMiuM is a recently developed R package for Bayesian clustering using a Dirichlet process mixture model. This model is an alternative to regression models, non-parametrically linking a response vector to covariate data ...
  • Procedure description : using AUTEC’s hydrophones surrounding a DTAGed whale to obtain localizations 

    Marques, Tiago A.; Shaeffer, Jessica; Moretti, David; Thomas, Len (University of St Andrews, 2015) - Report
  • Randomization-based models for multitiered experiments : I. a chain of randomizations 

    Bailey, Rosemary Anne; Brien, C. J. (2016-06) - Journal article
    We derive randomization-based models for experiments with a chain of randomizations. Estimation theory for these models leads to formulae for the estimators of treatment effects, their standard errors, and expected mean ...
  • A risk function for behavioral disruption of Blainville’s beaked whales (Mesoplodon densirostris) from mid-frequency active sonar 

    Moretti, David; Thomas, Len; Marques, Tiago A.; Harwood, John; Dilley, Ashley; Neales, Bert; Shaffer, Jessica; Mccarthy, E; New, Leslie Frances; Jarvis, S; Morrissey, Ron (2014-01) - Journal article
    There is increasing concern about the potential effects of noise pollution on marine life in the world’s oceans. For marine mammals, anthropogenic sounds may cause behavioral disruption, and this can be quantified using a ...
  • A simulation approach to assessing environmental risk of sound exposure to marine mammals 

    Donovan, Carl Robert; Harris, Catriona M; Milazzo, Lorenzo; Harwood, John; Marshall, Laura Helen; Williams, Robert (2017-02-28) - Journal article
    Intense underwater sounds caused by military sonar, seismic surveys, and pile driving can harm acoustically sensitive marine mammals. Many jurisdictions require such activities to undergo marine mammal impact assessments ...
  • Spatial models for distance sampling data : recent developments and future directions 

    Miller, David Lawrence; Burt, M Louise; Rexstad, Eric; Thomas, Len (2013-11) - Journal article
    Our understanding of a biological population can be greatly enhanced by modelling their distribution in space and as a function of environmental covariates. Density surface models consist of a spatial model of the abundance ...
  • Spatial variation in maximum dive depth in gray seals in relation to foraging. 

    Photopoulou, Theoni; Fedak, Mike; Thomas, Len; Matthiopoulos, Jason (2014-07) - Journal article
    Habitat preference maps are a way of representing animals’ space use in two dimensions. For marine animals, the third dimension is an important aspect of spatial ecology. We used dive data from seven gray seals Halichoerus ...
  • Statistical ecology comes of age 

    Gimenez, Olivier; Buckland, Stephen Terrence; Morgan, Byron J. T.; Bez, Nicolas; Bertrand, Sophie; Choquet, Remi; Dray, Stephane; Etienne, Marie-Pierre; Fewster, Rachel; Gosselin, Frederic; Merigot, Bastien; Monestiez, Pascal; Morales, Juan M.; Mortier, Frederic; Munoz, Francois; Ovaskainen, Otso; Pavoine, Sandrine; Pradel, Roger; Schurr, Frank M.; Thomas, Len; Thuiller, Wilfried; Trenkel, Verena; de Valpine, Perry; Rexstad, Eric (2014-12-24) - Journal article
    The desire to predict the consequences of global environmental change has been the driver towards more realistic models embracing the variability and uncertainties inherent in ecology. Statistical ecology has gelled over ...