Results 151 to 160 of about 999,023 (188)

The fallacy of the square root sampling rule†

Journal of the American Pharmaceutical Association (Scientific ed.), 1950
It is demonstrated that the determination of sample size as the square root of the lot size may create a sense of false security. Lot size alone is shown to provide an incomplete basis for determining sample size, whether by “square root” sampling or percentage sampling.
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The estimation of root length in samples and sub-samples

Plant and Soil, 1979
Methods for estimating the root length in a sample using the line intersect principle were compared. One method involved visual techniques and used simple equipment. Another method introduced a new machine designed to estimate root length automatically.
F. H. Goubran, D. Richards
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Square-Root and Cube-Root Estimators. The Developments in Sample Survey Theory

1969
Abstract : When the situation arises that the population being sampled is known, a priori, to have characteristics that place it in a more restricted category, the question rightly may be asked as to whether the condition of uniform unbiasedness might not be dropped and the bias and variance be combined into a single measure of mean square error.
H. O. Hartley, L. J. Ringer, O. C. Jenkins   +2 more
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SOIL SAMPLING FOR POTATO ROOT EELWORM CYSTS

Annals of Applied Biology, 1950
The National Agricultural Advisory Service (Advisory Entomologists) has adopted a uniform soil‐sampling technique for potato root eelworm. In Part I the recommended technique is quoted in full. In Part II an account is given of some experimental sampling done by the Advisory Entomologists, on which the recommendations are partly based.
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Total root length as estimated from small sub-samples

Plant and Soil, 1988
A method is proposed for estimating the total length of a root system from sub-samples. This method is based on the measurement of the length and diameter of small pieces of roots, and on the measurements of the bulk density of root sub-samples. It is assumed that roots are cylinders with a given bulk density.
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A Square Root Sampling Law for Signal Recovery

IEEE Signal Processing Letters, 2019
The problem of finding the optimal node density for reconstructing a stochastic signal from its noisy samples in sensor networks is considered. The signal could be nonstationary and nonbandlimited. A weight is assigned to each location that indicates the relative importance of the signal at that location.
Elaheh Mohammadi, Amin Gohari, Farokh Marvasti   +2 more
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A specialised soil corer for sampling tree roots

Soil Research, 2007
Sampling and measurement of tree root systems is arduous, expensive, and time-consuming. The lack of adequate and efficient equipment has resulted in the development of a new soil-root sampling apparatus which is able to sample tree roots of any diameter and soils of any hardness. This apparatus is inexpensive, compact, manoeuvrable, and very versatile
Stanley Sochacki, Peter Ritson, Bruce Brand   +2 more
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Correcting mathematically for soil adhering to root samples

Soil Biology and Biochemistry, 2002
Abstract Plant roots are important sources of new organic matter in soil, but measuring their mass and composition is sometimes made difficult by adhering soil particles. We propose a technique, based on carbon in ‘pure’ root tissue, to correct mathematically for soil contamination in measurements of root mass, nutrient concentrations, and isotopic ...
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Representative Sampling of Some Root Drugs

Planta Medica, 1989
Ch. Franz, W. Freytag, M. Lorenz, J. Schultze   +3 more
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Root caries in a sample of elderly persons.

The Journal of the Dental Association of South Africa = Die Tydskrif van die Tandheelkundige Vereniging van Suid-Afrika, 1998
With the anticipated increase in the aged adult population and the associated gingival recession, the prevalence of root caries is expected to increase. The purpose of this study was to determine the experience and distribution of root caries in a group of aged adults living in Kayelitsha. All non-institutionalized elderly black adults participating in
Louw A.J., Carstens I.L., Hartshorne J.E., van Wyk Kotze T.J.   +3 more
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