Results 51 to 60 of about 6,088,284 (323)

The unpredictably eruptive dynamics of spruce budworm populations in eastern Canada

Population Ecology, EarlyView.
We examine historical population data for spruce budworm from several locations through the period 1930–1997, and use density‐dependent recruitment curves to test whether the pattern of population growth over time is more consistent with Royama's (1984; Ecological Monographs 54:429–462) linear R(t) model of harmonic oscillation at Green River New ...
Barry J. Cooke, Jacques Régnière
wiley   +1 more source

The Ahlfors estimate [PDF]

Proceedings of the American Mathematical Society, 1979
The Ahlfors estimate gives an upper bound on the growth of a complete Hermitian metric on the punctured unit disc, whose Gaussian curvature is bounded above by − 1 - 1 . A. Sommese has obtained certain lower bounds on the growth as well. We answer two questions concerning lower bounds, raised by Sommese.
openaire   +2 more sources

Experimental estimation of one-parameter qubit gates in the presence of phase diffusion [PDF]

, 2009
We address estimation of one-parameter qubit gates in the presence of phase diffusion. We evaluate the ultimate quantum limits to precision, seek for optimal probes and measurements, and demonstrate an optimal estimation scheme for polarization qubits ...
Berihu Teklu Gebrehiwot, Davide Brivio, M. Hayashi, Marco G. Genoni, Matteo G. A. Paris, N. A. Nielsen, Simone Cialdi, Stefano Olivares, Stefano Vezzoli   +8 more
core   +2 more sources

Network topology drives population temporal variability in experimental habitat networks

Population Ecology, EarlyView.
Habitat patches connected by dispersal pathways form habitat networks. We explored how network topology affects population outcomes in laboratory experiments using a model species (Daphnia carinata). Central habitat nodes in complex lattice networks exhibited lower temporal variability in population sizes, suggesting they support more stable ...
Yiwen Xu, J. Angus Webb, William D. Bovill, Elise L. King   +3 more
wiley   +1 more source

Enhanced Estimation of a Noisy Quantum Channel Using Entanglement [PDF]

, 2001
We discuss the estimation of channel parameters for a noisy quantum channel - the so-called Pauli channel - using finite resources. It turns out that prior entanglement considerably enhances the fidelity of the estimation when we compare it to an ...
Cirone, Markus A., Fischer, Dietmar G., Freyberger, Matthias, Mack, Holger   +3 more
core   +2 more sources

occumb: An R package for site occupancy modeling of eDNA metabarcoding data

Population Ecology, EarlyView.
This study introduces a new R package, occumb, for the convenient application of site occupancy modeling using environmental DNA (eDNA) metabarcoding data. We outline a data analysis workflow, including data setup, model fitting, model assessment, and comparison of potential study settings based on model predictions, all of which can be performed using
Keiichi Fukaya, Yuta Hasebe
wiley   +1 more source

Estimating three- and four-parameter MIRT models with importance-weighted sampling enhanced variational auto-encoder

Frontiers in Psychology, 2022
Multidimensional Item Response Theory (MIRT) is widely used in educational and psychological assessment and evaluation. With the increasing size of modern assessment data, many existing estimation methods become computationally demanding and hence they ...
Tianci Liu, Chun Wang, Gongjun Xu
doaj   +1 more source

Compressive Parameter Estimation for Sparse Translation-Invariant Signals Using Polar Interpolation [PDF]

, 2015
We propose new compressive parameter estimation algorithms that make use of polar interpolation to improve the estimator precision. Our work extends previous approaches involving polar interpolation for compressive parameter estimation in two aspects: (i)
Duarte, Marco F., Fyhn, Karsten, Jensen, Søren Holdt   +2 more
core   +3 more sources

Between Droughts and Floods: The Seasonal Response of Freshwater Snails in Artificial Reservoirs in the Brazilian Semiarid Region

Population Ecology, EarlyView.
We investigate the seasonal dynamics of two freshwater snails, Biomphalaria straminea and Melanoides tuberculata, in artificial reservoirs of the Brazilian semiarid region. Despite regulated hydrology, B. straminea exhibited strong seasonal fluctuations associated with dry periods, while M. tuberculata maintained stable populations throughout the year,
Lucas Henrique Sousa da Silva, João Hemerson de Sousa, Adriana Josefa da Rocha, Manuella Feitosa Leal, Lucas Ariel de Sousa Aguiar, Tamaris Gimenez Pinheiro, Edson Lourenço da Silva   +6 more
wiley   +1 more source

A Method of Complex Disclosure Risk Assessment for Microdata

Journal of Probability and Statistics
This article proposes a method for constructing an aggregate measure of disclosure risk: the risk that a user or an intruder can derive an individual’s confidential information from a given data set.
Andrzej Młodak
doaj   +1 more source