Centre for Statistical Consultation​​​​​
Welkom by Universiteit Stellenbosch

Prof Daan Nel

                                                                                                                                                 

Daan.jpg  

Konsultant


E-pos: dgnel@sun.ac.za​


Telefoon: 021-8083240



                                                                                                                                                 

Verwerf D.Sc. aan die Universiteit van die Vrystaat in 1972.

 

Huidige navorsing belangstellings

Meerveranderlike heteroskedastisiteit, singuliere spektrum analise van tydreekse.

 

 

Publikasies in joernale

The h-th moment of the trace of a noncentral Wishart matrix.  S.Afr.Statist.J. (1971), 5,41-52.

On the moments of the trace of noncentral Wishart matrices and submatrices. S.Afr.Statist.J. (1972), 6, 93-102.

On some expectations with respect to Wishart matrices.S.Afr.Statist.J. (1973),7,61-67. (with D.J. de Waal.)

On the matrix differentiation of the characteristic roots of matrices. S.Afr.Statist.J. (1974), 8, 135-144. (with R.E. Bargmann.)

On the symmetric multivariate normal distribution and the asymptotic expansion of a Wishart matrix. S.Afr. Statist. (1978), 12, 145-159.

On matrix differentiation in Statistics. S.Afr.Statist. J. (1980), 14, 137-193.

Model selection,prediction and estimation for Multivariate normal populations. S.Afr.Statist.J. (1981), 15, 113-127. (with D.J. de Waal, A.J. van der Merwe, P.C.N. Groenewald, C.J. Lombard and S.Geisser.)

A predictive approach to the detection of additional information in a Multivariate regression model. Commun. Statist.-Theor.Meth., (1984), 13(17), 2119-2132. (with D.J. de Waal and D.G. Marx.)

Matric-t distribution. Encyclopedia of Statistical Sciences, (1985), Vol.5, Eds. N.L.Johnson and S. Kotz, John Wiley and Sons,Inc.,316-320. (with D.G. Marx.)

A matrix derivation of the asymptotic covariance matrix of sample correlation coefficients. Linear Algebra and  its Applications. (1985), 67, 137-145.

A solution to the Multivariate Behrens-Fisher problem. Commun.Statist.-Theory Meth., (1986), 15(12),  3719-3735. (with C.A.van der Merwe.)

A profile analysis for two groups under the heteroscedastic assumption. Commun.Statist.-Theory  Meth,.(1987) 16(12), 3577-3590.

Linear generalizations of various matric-t distributions. Commun. Statist.-Theory Meth., (1987), 16(12), 3665-3682. (with C.A.van der Merwe.)

A procedure to select a ML-II prior in a Multivariate normal case. Commun.Statist.Sim.Comp. (1988),17(3), 1021-1035. (with D.J.de Waal.)

On the exact distribution of the univariate and multivariate Behrens-Fisher statistics with a comparison of several solutions in the univariate case. Commun. Statist. - Theory Meth. (1990), 19(1), 279-298. (with Cay van der Merwe and Barry K. Moser.)

Daylength determines departure date of the spotted flycatcher Muscicapa Striata from its winter quarters. Ardea, 79(1) (1991), 63-65.(with Ordino B. Kok and C.A. van Ee.)

A Bayesian approach to the multivariate Behrens-Fisher problem under the assumption of proportional covariance matrices. TEST (1993), ol 2, No. 1, 15 - 28. ( with P.C.N. Groenewald.)

A comparison of the significance levels and power functions of several solutions to the multivariate Behrens-Fisher  problem.  S.Afr. Statist. J. (1993), Vol. 27, 129-148 (with N. de la Rey.)

A test to determine closeness of multivariate Satterthwaite's Approximation. Journ. Mult. Anal. (1994), Vol. 51, No. 1, 201 - 209. (with A.I. Khuri and T. Mathew.)

Simultaneous detection of shift in means and variances. (with B. Flury and I. Pienaar.) Journ. Amer. Statist. Assoc. (1995), Vol. 90, No.432. 1474 – 1481.

Tests for equality of parameter matrices in two multivariate linear models. Journ.Mult.Anal. (1997), Vol.61, No.1, 29-37.

The decomposition of the Behrens-Fisher statistic in q-dimensional common principal component submodels.(with I. Pienaar) Ann. Inst. Statist. Math. (1998) , Vol.50, No.2, 241-252

Allometric Extension.(with B. Flury and S. Bartoletti) Biometrics.(1999), Vol.55, No.4,1210-1214

On a Fisher-Cornish Type Expansion of Wishart Matrices.  Chapter 16, p. 223 - 232 in: Innovations in Multivariate Statistical Analysis. A Festschrift for Heinz Neudecker. (with P.C.N. Groenewald)  Ed.  R.D.H. Heijmans, D.S.G. Pollock and A. Satorra. Kluwer Academic Publications (2000), Dordrecht/  Boston/ London.

On the distribution of the estimator of Cronbach's alpha. (with J.M. van Zyl and H. Neudecker.) Psychometrika (2001), Vol. 65, No.3, 271 – 280.

A comparison of approximate confidence interval methods for the difference between two independent binomial proportions. (with M. Nel, R. Schall and G. Joubert). (2002) S. Afr. Statist.J., 36, 77-95.

Fluoxetine decreases stereotypic behavior in primates. (with C.Hugo, J. Steier, C. Mdhluli, B.H. Harvey, D. du Toit, Swolfe-Coote en D. Stein) (2003) Progress in Neuro-Psychopharmacology & Biological Psychiatry.

A comparison of the accuracy of two methods used by pre-doctoral students to measure vertical   dimension. (G.A.V.M. Geerts, M.E. Stuhlinger, D.G. Nel), The Journal of Prosthetic Dentistry, ( 2004) 91, 59 – 66.

Cluster analysis of obsessive-compulsive spectrum disorders in patients with obsessive-compulsive disorder: clinical and genetic correlates. (C. Lochner, S.M.J. Hemmings, C.J. Kinnear, D.J.H. Niehaus, D.G. Nel, V.A. Corfield, J.C. Moolman-Smook, S. Seedat , D.J. Stein) Comprehensive Psychiatry, (2005), 46,14-19.

Obsessive-compulsive disorder and trichotillomania : a phenomenological  comparison. C Lochner, S.Seedat, P.L. du Toit , D.G Nel , D.J.H. Niehaus, R.Sandler and  D.J. Stein. BMC Psychiatry, (2005), 5 :2 doi : IO.1186/1471-244X-5-2 http:/www.biomedcentral.com/1471-244X/5/2.

Rapid screening of the fermentation profiles of wine yeasts by Fourier transform infrared  spectroscopy.  H. Nieuwoudt, I.S. Pretorius, F.F. Bauer D.G Nel  and B.A. Prior. Journal of Microbiological Methods.  67 (2006) 248 – 256.

Development, microbiological content and sensory analysis of a spread rich in n-3 fatty acids. A.Dalton,  R.C. Witthuhn, C.M. Smuts, P. Wolmarans, D.G. Nel.  Food Research International  (2006);  39(5) : 559-567.

Exploratory and confirmatory factor analysis of the Multidimensional Anxiety Scale for Children (MASC) among adolescents in the Cape Town metropole of South Africa. Dylan Fincham, Johannes Schickerling, Michael Temane, Daan Nel, Winnie De Roover and Soraya Seedat. Depression and  Anxiety 0: 1-7, (2007).

The Neuropsychiatry and Neuropsychology of Lipoid Proteinosis. Helena B.Thornton, Daan Nel,  Dorothy Thornton, Gus A. Baker, Dan J. Stein & Jack van Honk, Journal of Neuropsychiatry and Clinical Neurosciences.20:1, (Winter 2008), p86-92.

Depression and anxiety in multisomatoform disorder: Prevalence and clinical predictors in primary care. Muller J.E, Wentzel I, Nel D.G. and Stein D.J. South African Medical Journal; (2008), 98(6), 473- 476.

Alcohol-Induced Psychotic Disorder: A Comparitive Study on the Clinical Characteristics of Patients with Alcohol Dependence and Schizophrenia. G.P. Jordaan, D.G. Nel, R.H. Hewlett and R. Emsley. Journal of Studies on Alcohol and Drugs. (2009)  870- 876.

Does carbimazole have an effect on I-131 therapy in Graves disease? Annare Ellmann, NasonLambwe, Daan Nel and Stephen Hough. J Nucl Med. (2009), 50 (Supplement 2):431

Acute renal failure in the medical ICU still predictive of high mortality. DV Friedericksen, L van der Merwe, DG Nel and MR Moosa. South African Medical Journal (2009) Vol.99, No.12, 873-875.

Common singular spectrum analysis of several time series. H. Viljoen and D.G. Nel              Journal of Statistical Planning and Inference,Vol.140,1, (2010) 260-267.

Relationships between drying defect parameters and some growth characteristics in kiln-dried South African grown Eucalyptus grandis poles. P. Mugabi, T. Rypstra, H. F. Vermaas and  D.G. Nel. European Journal of Wood and Wood Products (2010); 68: 329-340.

The aetiology of adult burns in the Western Cape, South Africa. David Maritz, Lee Wallis, Elbie van der Merwe and Daan Nel. Burns (2011) Published online:10.1016/ J.Burns.2010.12.007

Correlation between drying effects, their parameters and the moisture gradient in kiln-dried, (2010) South African grown Eucalyptus Grandis Poles. Maderas Ciencia y Tecnologia 12(3) 199-208.

Effect of kiln drying schedule on the quality of South African grown Eucalyptus grandis poles. P. Mugabi, T. Rypstra, H.F. Vermaas, and D.G. Nel. European Journal of Wood and Wood products (2011), 69: 19-26.

Suitability of auger drill sampling for the measurement of moisture content gradient in kiln-dried South African grown Eucalyptus grandis poles. . P. Mugabi, T. Rypstra, H. F. Vermaas and  D.G. Nel. European Journal of Wood and Wood Products (2011); 68: 329-340.

Alcohol-induced psychotic disorder: brain perfusion and psychopathology—before and after anti-psychotic treatment Gerhard P. Jordaan & James M. Warwick & Daan G. Nel & Richard Hewlett & Robin Emsley (2012) Metabolic Brain Disease 27(1) 66-77.

Predicting mortality and length-of-stay for neonatal admissions toprivate hospital neonatal intensive care units: a Southern African retrospective study. P.T. Pepler, D.W. Uys & D.G. Nel (2012) African Health Sciences, Vol 12, No 2, 166-173.

Translation and validation of European Organisation for Research and Treatment of Cancer QLQ- CX24 questionnaire into the indigenous African languages of isiXhosa and Afrikaans.  G.C. du Toit and D.G. Nel (2012) South Afr J Gynaecol Oncol , Vol 4 No 2, 59-62.

Fetal heart rate patterns at 20 to 24 weeks gestation as recorded by fetal electrocardiography. Hofmeyr F, Groenewald CA, Nel DG, Myers MM, Fifer WP, Signore C, Hankins GDV, Odendaal HJ, for  the PASS Network (2013) The Journal of Maternal-Fetal & Neonatal Medicine doi:0.3109/14767058.2013.836485.

Variation in strength, stiffness and related wood properties in young SoutAfrican-grown Pinus patula. C.B. Wessels, F.S. Malan, D.G. Nel and T Rypstra. Southern Forests, (2014), 76(1): 37-46

Probiotics, feeding tolerance, and growth: a comparison between HIV-exposed and         unexposed very low birth weight infants. E. van Niekerk, G.F.Kirsten, D.G. Nel, R. Blaauw. Nutrition, (2014), Jun; 30(6) 645-653

Human Milk Oligosaccharides differ between HIV-Infected and HIV-Unibnfected mothers and are related to Necrotizing Enterocolitis incidence in their preterm very-low-birth-weight infants. E. van Niekerk, C.A. Autran, D.G. Nel, G.F. Kirsten, R, Blaauw and L.Bode. J. Nutr. (2014): 8 1227 -1233.(Published on line June 11, 2014)

 A comparison of some methods for the selection of a common eigenvector model for the covariance matrices of two groups. P.T. Pepler, D.W. Uys , D.G Nel. Communications in Statistics- Simulation and Computation. (2014):  DOI 10.1080/03610918.2014.932801,(Accepted paper published on line October 30, 2014)

 

Besoeke aan universiteite

  • Universiteit van Georgia: September 1973 - March 1974 en January - July 1979.
  • Stanford Universiteit: June - August 1984 en June - August 1995.
  • Indiana Universiteit: June - August 1992 en January – June 1997.
  • Scuola Matematica Interuniversitaria in Perugia, Italy: 23 July -  28 August 1999​.

 

Verenigings en komitees

  • Genoot van die Suid Afrikaanse Statistiese Vereniging (SASV).
  • President van die  SASV (1982).
  • Lid van die SASV woordeboek komitee (1984).
  • Mede redakteur van die SASV joernaal (1982-1984), (1991- 1999).​