The neutral theory of S. P. Hubbell postulates a two-scale hierarchical framework consisting of a metacommunity following the speciation-drift equilibrium characterized by the "biodiversity number" theta, and local communities following the migration-drift equilibrium characterized by the "migration rate" m (or the "fundamental dispersal number" I). While Etienne's sampling formula allows simul...

When properly applied, stereology is a very robust and efficient method to quantify a variety of parameters from biological material. A common sampling strategy in stereology is systematic random sampling, which involves choosing a random sampling [corrected] start point outside the structure of interest, and sampling relevant objects at [corrected] sites that are placed at pre-determined, equi...

in order to study seed hardening process in pomegranate, some of the relevant biochemical parameters were evaluated in fleshy part of arils or seeds in various soft and hard seeded pomegranate genotypes from the initial fruit set upto ripening stages. lignin was determined from the seeds and enzyme assays were performed on the flesh of arils. analysis of variance revealed significant difference...

Multi-structure model fitting has traditionally taken a two-stage approach: First, sample a (large) number of model hypotheses, then select the subset of hypotheses that optimise a joint fitting and model selection criterion. This disjoint two-stage approach is arguably suboptimal and inefficient — if the random sampling did not retrieve a good set of hypotheses, the optimised outcome will not ...

We apply the techniques of response surface methodology (RSM) to approximate the objective function of a two-stage stochastic linear program with recourse. In particular, the objective function is estimated, in the region of optimality, by a quadratic function of the firststage decision variables. The resulting response surface can provide valuable modeling insight, such as directions of minimu...

5.1 Overview this chapter describes the tiMSS 2007 sample design, which consists of a set of specifications for the target and survey populations, sampling frames, survey units, sample selection methods, sampling precision, and sample sizes. the sample design is intended to ensure that the tiMSS 2007 survey data provide accurate and efficient estimates of national student populations. Since mea...

The main focus of this paper is in a discussion of complexity of stochastic programming problems. We argue that two-stage (linear) stochastic programming problems with recourse can be solved with a reasonable accuracy by using Monte Carlo sampling techniques, while multi-stage stochastic programs, in general, are intractable. We also discuss complexity of chance constrained problems and multi-s...

A dual-clock MASH (multi-stage noise shaping) deltasigma modulator (DSM) is proposed for high performance analog-digital converter. This employs a DSM using a frequency modulated intermediate signal (FMDSM) for the last stage. The sampling clock frequency for the last stage can be increased due to the features of the FMDSM. It is shown that this can increase the SNR beyond the conventional MASH...

In this paper, we have derived difference, regression and predictor estimators for two-stage sampling with unequal first-stage units using multivariate auxiliary information. The mean square error of these estimators have been derived. A numerical illustration is given for finding the relative comparisons. 2003 Elsevier Inc. All rights reserved.

BACKGROUND Missing data on tumour stage information is a common problem in population-based cancer registries. Statistical analyses on the level of tumour stage may be biased, if no adequate method for handling of missing data is applied. In order to determine a useful way to treat missing data on tumour stage, we examined different imputation models for multiple imputation with chained equatio...