Densities of functions of two or more independent random variables can be estimated by local U-statistics. Frees (1994) gives conditions under which they converge pointwise at the parametric root-n rate. Uniform convergence at this rate was established by Schick and Wefelmeyer (2004) for sums of random variables. Giné and Mason (2007) give conditions under which this rate also holds in Lp-norms...

h 1989, two levels each of stand density and fertilization were factorially established in an 8-year-old loblolly pine plantation on a P-deficient site. Levels of stand density were nonthinned at 2,732 trees per hectare and thinned at 721 trees per hectare. Fertilizer levels were none or application of 150 kilograms P plus 135 kilograms N per hectare. In 1994, stand basal areas of the nonthinne...

Plant root systems are highly plastic in their development and can adapt their architecture in response to the prevailing environmental conditions. One important parameter is the availability of phosphate, which is highly immobile in soil such that the arrangement of roots within the soil will profoundly affect the ability of the plant to acquire this essential nutrient. Consistent with this, t...

The kernel density estimator is used commonly for estimating animal utilization distributions from location data. This technique requires estimation of a bandwidth, for which ecologists often use least-squares cross-validation (LSCV). However, LSCV has large variance and a tendency to under-smooth data, and it fails to generate a bandwidth estimate in some situations. We compared performance of...

this study analyzed the relationship between the vertical distribution of root biomass and soil organic carbon (soc)content in the arid shrub lands of semnan province in iran. three sites were selected based on differences in canopy coverof artemisia sieberi (5%, 10% and 15%). average density of shrubs, root biomass and soc were determined at differentdepths (0-20, 20-40, 40-60, 60-80 cm) in 20...

A large body of nonparametric statistical literature is devoted to density estimation. Overviews are given in Silverman (1986) and Izenman (1991). This paper addresses the problem of univariate density estimation in a novel way. Our approach falls in the class of so called projection estimators, introduced by Cencov (1962). The orthonor-mal basis used is a basis of compactly supported wavelets ...