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Jens Feder Fractal Structures and Self Organization (TMR network) Fractals; Flow in Porous Media; Granular Materials; Fracture Mechanics; Friction. Available in: Hardcover. This lovely little book will take off and fly on its own power, but the author has asked me to write a few words, and one. Jens Feder is the author of Fractals ( avg rating, 2 ratings, 0 reviews, published ), Fractals in physics ( avg rating, 0 ratings, 0 reviews.

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The length of the longest finger as a function of time is accurately described by the results of a new form of DLA simulation which in addition to DLA structures gives the time dependence in a form suitable for comparison with experiments. Skip to main content. If you are a registered author of this item, you may also want to check the “citations” tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

Last but not least, we are all grateful to Jens for not having allowed undue personal modesty to deprive us of accounts of his own group’s varied and excellent work. We have no references for this item. One practical consequence in mineral exploration could be the possible existence of numerous economically interesting regional to continental geochemical provinces on earth. You can help adding them by using this form.

Phys. Rev. A 36, () – Dynamics of viscous-fingering fractals in porous media

For a fractal surface, the semi-variogram will follow the equation Man- delbrot,p. The corresponding fre- quency distribution curves are shown in Fig. However, log transformation is rarely veder in this connection because the variance become enlarged by possible poor precision of the chemical analyses at low concentrations, which may result in too much noise for detecting real variations at higher concentrations.

Classes of such patterns are listed in Table 2 and illustrated by examples in Figs. The east-south crossing zone of high Ba concentrations coincides with the Main Sulphide Belt of Finland K a h m a, w h i c h c o n – t a i n s some of the country’s most important economic sulphide deposits.


Please view eBay estimated delivery times at the top of the listing. Note the logarithmic scale of the axes. This method of testing for fractal dimensions is advantageous because se- lection of coastlines contours can be adjusted according to the sensitivity of the analytical method, thus avoiding substantial errors due to poor analyt- ical precision at low concentrations. Areal fractal dimensions, Dn, ffeder 2.

For log-normal type distributions which is common for trace elementsthe variogram may have the “ideal” shape even though the data are fractal and well within the lower and upper practical limits of sampling. In this case Dt is 1. DI can be easily calculated by computing the logarithms of eq.

This allows to link your profile to this item. The Hurst exponent H for A1 is calculated to 0.

The fractal nature of geochemical landscapes | Torstein Jøssang and Jens Feder –

Series I Physics Physique Fizika. This value for D is an upper limit since estimation from variograms, leads to positively biased results if the data are log-normal and of a limited preci- sion at low concenctrations. This typically gave 65 independent linear equations for each estimated concentration. These are typical properties of fractal objects – – they have a fractal dimension. Developments in regional geochemistry for mineral exploration. Geological Surveys of Finland, Norway and Sweden, 20 pp.

The fractal di- mension for the total coastline contour is given by DI 1. In such cases, log transformation of concentrations before calculating variances would produce a variogram with- out a sill, even for log-normal distributions. In the past the application of geochemical surveys in exploration have gen- erally been based on geological modelling.

Jens Feder

A sampling station was located at the downstream end o f each drainage area. However, the “ideal” semivariogram Fig. Weyl fermions are observed in a solid. For exploration geochemists, the practical consequences are of particular interest and these will be discussed towards the end of the paper.

In the case of geochemical dispersion patterns obtained within a certain area, the lower length scale is the sampling interval and the upper length fratcals is the linear dimension of the survey area. Oxidates as a geohcemical sampling medium in granitic terrain. A system- atic step by step procedure with progressively increasing intensity of measure- ments in target areas of successively decreasing size, would be more cost effi- cient than complete surveys of whole areas in one step.


This steady increase for all values of h is a consequence of the self-similarity of fractal patterns at all scales. We con- clude that the data are fractal characterized by dimensions DA in the range 2.

The reason for misfit of some of the variograms with eq. The grade units given are proportional to the measured grades. In such surveys tens of thousands of samples have often been collected initially in order to obtain comprehen- sive coverages of large survey areas in a single step. Simulation of geological surfaces using fractals. The other three methods are less direct because they require interpolation of geochemical concentrations between sample points to obtain isoconcentration contours.

Outside these limits the empirical geochemical landscape is mathematically nonexistent; the var- iance, consequently approaches a constant value as h approaches the linear dimension of the survey area. Within each 30 k m 2 o f thek m 2 sur- vey region one drainage area approximately 10 k m 2 in size was selected for sampling. The area-perimeter relation for AI Fig. Visualization of geochemical data on map: More about this item Statistics Access and download statistics Corrections All material on this site has been provided by the respective publishers and authors.

A widely accepted m e t h o d Kriging is available for such interpolation see for example, Clark, Download full text from publisher File URL: Geochemical Atlas of Fin- land: If you have authored this item and are not yet registered with RePEc, we encourage you to do it here.