Results 261 to 270 of about 83,949 (294)

Line-transects : Sampling application to a French Guianan rainforest Running head : line-transects sampling in French Guiana

mamm, 2000
La gestion des ressources naturelles est une preoccupation recente en Guyane. Les sites d'etude se multiplient dorenavant sur le territoire. L'evaluation des impacts de la chasse et de l'exploitation forestiere sur les populations de grands mammiferes et oiseaux constitue un axe de recherche privilegie. Les methodes d'inventaire par transects lineaires
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Line Transect Sampling with Unknown Probability of Detection along the Transect

Biometrics, 1989
SUMMARY A model is given for line transect sampling for the purpose of estimating animal population density which makes no assumption about the value of the detection probability along the transect or about the form of the detection probability function other than continuity.
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Asymptotic Unbiased Kernel Estimator for Line Transect Sampling

Communications in Statistics - Theory and Methods, 2011
In this article, we propose a new estimator for the density of objects using line transect data. The proposed estimator combines the nonparametric kernel estimator with parametric detection function: the exponential or the half normal detection function to estimate the density of objects.
Omar Eidous, M. K. Shakhatreh
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Efficiency and Bias in Strip and Line Transect Sampling

The Journal of Wildlife Management, 1985
Efficiency and relative bias of strip transect and line transect (Fourier series estimator) survey methods were compared. Comparisons involved the negative exponential and half-normal detection functions for expected sample sizes of 40, 60, and 100 and three levels of spatial aggregation. Efficiency and bias were computed as functions of strip transect
Kenneth P. Burnham, David R. Anderson, Jeffrey L. Laake   +2 more
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Adjusting for Group Size Influence in Line Transect Sampling

The Journal of Wildlife Management, 1990
In some line transect surveys, the population of interest consists of groups or clusters of individuals rather than single items. If group size influences the probability of detecting a group, then the observed group size data are size-biased. This can lead to overestimation of the true mean group size and hence could lead to overestimation of the ...
Thomas D. Drummer, Anthony R. Degange, Larry L. Pank, Lyman L. McDonald   +3 more
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Window Sensitivity Functions for Line Transect Sampling

Environmental Management, 1998
/ The estimation of animal or plant abundance by the line or belt transect sampling method has been investigated by many authors, including biologists, statisticians, biometricians, wildlife scientists, and fisheries and forestry specialists. The method has reached wide acceptance over the last 30 years, and the theoretical development has continued to
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Line intersect sampling: Ell-shaped transects and multiple intersections

Environmental and Ecological Statistics, 2003
The probability of selecting a population element under line intersect sampling depends on the width of the particle in the direction perpendicular to the transect, as is well known. The consequence of this when using ell-shaped transects rather than straight-line transects are explicated, and modifications that preserve design-unbiasedness of Kaiser's
Timothy G. Gregoire, Harry T. Valentine
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Estimating Population Size and Density Using Line Transect Sampling

Biometrical Journal, 1985
AbstractANDERSON and POSPAHALA (1970) investigated the estimation of wildlife population size using the belt or line transect sampling method and devised a correction for bias, thus leading to a class of estimators with desirable characteristics. This work was given a basic and rigorous mathematica framework by BURNHAM and ANDERSON (1976).
D. R. Anderson, K. P. Burnham, B. R. Crain   +2 more
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Variable location kernel method using line transect sampling

Environmetrics, 2010
The variable location kernel (VLK) method provides a nonparametric estimator for a probability density function. This article proposes the VLK method to fit line transect data in order to estimate the density of a biological population. The method produces two promising estimators for the density of objects which improve upon the performance of the ...
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Asymptotic properties of estimators derived from line transect sampling

Communications in Statistics - Theory and Methods, 1983
Line transect sampling of two-dimensional figures generates information for the estimation of areal fractions and boundary length per unit area. The individual estimators are unbiased and variance approximations for the estimators are developed, based on the information available from a single line transect.
James R. Lackritz, Richard L. Scheaffer
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