نتایج جستجو برای: population statistics

تعداد نتایج: 846546  

2006
Shuo-sheng Wu Xiaomin Qiu

This study presents a method to model population densities by using image texture statistics of semi-variance. In a case study of the City of Austin, Texas, we first selected sample census blocks of the same land use to build population models by land use. Regression analyses were conducted to infer the relationship between block population densities and image texture statistics of the semivari...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2007
E Brunet B Derrida A H Mueller S Munier

We consider a family of models describing the evolution under selection of a population whose dynamics can be related to the propagation of noisy traveling waves. For one particular model that we shall call the exponential model, the properties of the traveling wave front can be calculated exactly, as well as the statistics of the genealogy of the population. One striking result is that, for th...

2010
A. Alfons S. Kraft M. Templ P. Filzmoser Andreas Alfons Stefan Kraft Matthias Templ Peter Filzmoser

Statistical simulation in survey statistics is usually based on repeatedly drawing samples from population data. Furthermore, population data may be used in courses on survey statistics to explain issues regarding, e.g., sampling designs. Since the availability of real population data is in general very limited, it is necessary to generate synthetic data for such applications. The simulated dat...

Journal: :Statistical Methods and Applications 2011
Andreas Alfons Stefan Kraft Matthias Templ Peter Filzmoser

Statistical simulation in survey statistics is usually based on repeatedly drawing samples from population data. Furthermore, population data may be used in courses on survey statistics to explain issues regarding, e.g., sampling designs. Since the availability of real population data is in general very limited, it is necessary to generate synthetic data for such applications. The simulated dat...

Journal: :Neural computation 2005
Shun-ichi Amari Hiroyuki Nakahara

Fisher information has been used to analyze the accuracy of neural population coding. This works well when the Fisher information does not degenerate, but when two stimuli are presented to a population of neurons, a singular structure emerges by their mutual interactions. In this case, the Fisher information matrix degenerates, and the regularity condition ensuring the Cramér-Rao paradigm of st...

Journal: :Theoretical population biology 2001
N M Sundell R T Durrett

Statistical tests are needed to determine whether spatial structure has had a significant effect on the genetic differentiation of subpopulations. Here we introduce a new family of statistics based on a sum of an exponential function of the distances between individuals, which can be used with any genetic distance (e.g., nucleotide differences, number of nonshared alleles, or separation on a ph...

بانوئی, علی اصغر, محمودی, مینا,

Up to three decades ago, economic statistics could systematically meet the statistical needs and economic views quantitative analyses requirements (known as growth – centered views) in the framework of national accounts and input-output tables. However, owing to the insensitivity of these views to simultaneous survey of socio-economic issues, no attention has been paid to systematizing social s...

1997
M. Bloznelis

Suppose that U is a U-statistic of degree two based on N random observations drawn without replacement from a nite population. For the distribution of a standardized version of U we construct an Edgeworth expansion with remainder O(N ?1) provided that the linear part of the statistic satisses a Cram er type condition.

2010
Satohiro Tajima Masato Okada

The power law provides an efficient description of amplitude spectra of natural scenes. Psychophysical studies have shown that the forms of the amplitude spectra are clearly related to human visual performance, indicating that the statistical parameters in natural scenes are represented in the nervous system. However, the underlying neuronal computation that accounts for the perception of the n...

Journal: :Genetics 1993
T Prout J S Barker

Drosophila buzzatii is confined to reproducing in a well defined patchy environment consisting of rotting cactus cladodes which are ephemeral, permitting at most three generations. Flies emerging from such rots were used to estimate the additive genetic variance within rots and the genetic variance between rots for body size and also were electrophoresed to determine their genotypes at six poly...

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