... You can assume a fractional isotropic Brownian motion (fBm) model (the "power law" model) of the form Gamma = kh^a where a can vary between 0 and 2 but not...
804
Ruben Roa
rroa@...
Dec 19, 2002 8:40 am
... log-likelihood of a model as estimator of the mean expected log-likelihood, this bias being a function of the number of free parameters in the model. So it...
805
Brian R Gray
brgray@...
Dec 19, 2002 8:40 am
REML = variously, restricted or residual ML. the kicker is that, under REML, a function of the outcomes are estimated, such that the function contains none of...
806
Adrian Martínez Va...
amvargas@...
Dec 28, 2002 2:11 pm
Hola dear Mail List Friends. I have some problems with the treatment to the "Negativity Pints" that cause negatives Kriging coefficients: Z=Sum [Landa(i) *...
807
Isobel Clark
drisobelclark@...
Jan 2, 2003 8:22 am
Brian There is an immense amount of literature on mixtures of distributions, generally Normal or lognormal. Unfortunately, I don't have my 1974 paper up on the...
808
Isobel Clark
drisobelclark@...
Jan 2, 2003 8:22 am
Digby The original derivation of the kriging equations does not demand any specific distribution. However, it only makes sense if the 'increments' - difference...
809
Brian R Gray
brgray@...
Jan 2, 2003 8:22 am
someone recently commented on the central limit theorem not being applicable to mixture distributions. this seems sensible but, given that that's all I've...
810
Digby Millikan
digbym@...
Jan 2, 2003 8:22 am
Brian, I am not familiar with the derivation of kriging equations, but of note I know the lognormal population does not follow the central limit theorem, and...
811
Digby Millikan
digbym@...
Jan 2, 2003 8:22 am
Francis, Have you looked at indirect lognormal corrections and affine corrections for sample sizes. Many kriging softwares use diffrent sample sizes for their...
812
Digby Millikan
digbym@...
Jan 3, 2003 8:38 am
Francis, On topic in "Lognormal-de Wijsian Geostatistics for Ore Evaluation" D.G.Krige pp5. points out that the slope of the log-probability plot provides an...
813
Digby Millikan
digbym@...
Jan 3, 2003 8:38 am
Francis, Having looked at your website further comments regarding the Australian gold mining industry that only 2 out of 35 operations acheived feasibility...
814
Digby Millikan
digbym@...
Jan 7, 2003 8:25 am
Hello, Does anyone know the first paper to discuss the covariogram or twin variogram in relation of variability of grades with distance in orebodies. Regards...
815
david boakye
david.boakye@...
Jan 7, 2003 8:25 am
Hello Does anyone know of an undeground alternative to open pit optimisation? How would you derive underground reserves from a 3-dimensional resource block...
816
Colin Daly
colin@...
Jan 7, 2003 8:25 am
Hi Digby and Isobel, Just another bit to add on the variogram. There is a large body of work that was done in the Soviet Union by Kolmogorov and his school. He...
817
Digby Millikan
digbym@...
Jan 7, 2003 8:25 am
David, If you want clarification of any of these points please do not hesiate to contact me. This is the method employed at all mines where stope design is...
818
Ruben Roa
rroa@...
Jan 7, 2003 8:25 am
Dear list members: I run into problems when creating data files with Excel 2002 for use in Variowin 2.2 Prevar2d module. Variowin says it finds an 'error while...
819
Digby Millikan
digbym@...
Jan 7, 2003 8:25 am
Hello, In regards to my last email, Isobel corrected me, I meant to say the covariance graph with distance i.e. the 'upside down variogram' not the covariogram...
820
Allison, Craig
Craig.Allison@...
Jan 7, 2003 8:25 am
Hello, I was hoping advice could be given on the following problem. We store nickel (eg 0.40 Ni %) and mill recovery (55.45%) in our mine model. From this we ...
821
Isobel Clark
drisobelclark@...
Jan 7, 2003 8:25 am
Digby There is a 96 page bibliography in the back of Cressie's book! Cressie, Noel A. C., Statistics for Spatial Data, Revised Edition, 1993, John Wiley &...
822
Isobel Clark
drisobelclark@...
Jan 7, 2003 8:25 am
Colin Thanks for the info. I knew that Matheron had considerable correspodence with Gandin in Russia, who was working in meteorology but have no references to ...
823
Digby Millikan
digbym@...
Jan 7, 2003 8:25 am
Calculating averagesCraig, Don't you mean multiply Average Nickel Head grade by Average Mill recovery. Your first figure 0.3342 is correct but your figure...
824
Isobel Clark
drisobelclark@...
Jan 7, 2003 8:25 am
Hi Craig The average of a product will only equal the product of the averages if the two numbers are completely independent of one another. This is exactly...
825
Digby Millikan
digbym@...
Jan 7, 2003 8:25 am
Hi David, I have designed the Gecko underground mine optimally from a block model (Gecko Mine N.T. 80 stopes). It is easier than pit optimisation because you...
826
Digby Millikan
digbym@...
Jan 8, 2003 9:16 am
Hello, I was wondering if someone could give me recommendations on 'Lognormal Distributions: Theory and Applications' Edwin L. Crow for one interested in...
827
Ruben Roa
rroa@...
Jan 9, 2003 9:08 am
... file as an input for Variowin Prevar. Obviously it won't work for several reasons (a) Variowin uses the same file format as GEOEAS, a plain ASCII file, (b)...
828
Pierre Goovaerts
goovaert@...
Jan 9, 2003 9:08 am
Hi Ruben, I am also working on Windows XP and have repeated your experiment. I can read the file created from Excel (option formatted text, space delimited) ...
829
Digby Millikan
digbym@...
Jan 9, 2003 9:08 am
Hello everyone, Here is a summary of my question about information on lognormal distributions in mining. ... Jeff Myers wrote: I can't help on the reference,...
830
Janusz Szmyt
jachszm@...
Jan 9, 2003 4:32 pm
Hello, My name is Janusz Szmyt. I am looking for scientists who are interested in the spatial distribution of trees within stands. Regards, Janusz [Non-text...
831
Edzer J. Pebesma
e.pebesma@...
Jan 9, 2003 4:32 pm
I have a thesis in front of me called "Statistical sampling and modelling for cork oak and eucalyptus stands", written by Maria Joao Paulo. This may be ...
832
Jörgen Wallerman
Jorgen.Wallerman@...
Jan 10, 2003 8:39 am
Dear Mr Szmyt and list members, Maybe you can find what you need in any of these? Bellehumeur, C., and Legendre, P. 1998. Multiscale sources of variation in ...
