Georgios Tzavelas

Georgios Tzavelas


Full name: Georgios Tzavelas

Role: Associate Professor

Department: Statistics and Insurance Science

Office: 307/Main Bld.


Phone/Fax: +30 210 4142310

Position Associate Professor in Probability and Statistics

Research Interests

Estimation, Characterization problems, Environmental Statistics, Biostatistics


  • 1994 –  Ρh.D. in Mathematical Statistics, University of Maryland at College Park, U.S.A.
  • 1991 – Master of Arts in Mathematical Statistics, University of Maryland at College Park, U.S.A.
  • 1984  -Bachelor’s degree in Mathematics, University of Patras, Greece


University of Maryland at College Park, U.S.A  / Undergraduate Studies Professional Development

  • Excellence in Teaching- .- November  1993

University of Patras, Greece

  • Ranked in top 5% of students                                 1981, 1982, 1983

Referee in:

  • Applied Statistics
  • Journal of Information and Mathematical Sciences
  • Journal of Statistical Computation and Simulation
  • Communication in Statistics – Theory and Method
  • Communication in Statistics – Simulation and Computation

Undergraduate level

  • Sampling methods and Techniques 
  • Statistics I-Estimation
  • Statistics II (Department of Banking and Financial Management))

Grduate Level

Program of Applied Statistics 

  • Clinical Trials
  • Biostatistics

Program in  Actuarial Science and Risk Management

  • Loss distributions and theory of extreme values


  • A. Methodological

A.27 G. Tzavelas, C. Koutropoulou, K.Politis (2020). Some properties of the failure rate function for the mixtures of  Erlange distributions  /

A.26 P. Economou, G. Tzavelas  and A. Batsidis (2020). Robust inference under r-size-biased sampling without replacement from finite population. Journal of Applied Statistics  47 (13-15): 2808-2824

Α.25 P. Economou, A. Batsidis and G. Tzavelas (2020).  Berkson’s paradox and weighted distributions: An application to Alzheimer’s disease. Biometrical Journal62(1):238-249

Α.24 D. Panaretos, G.  Tzavelas, M.  Vamvakari  and  D.  Panagiotakos (2020). Investigating the role of rotation in factor analysis, in regard to the repeatability of the extracted factors: a simulation study based on the 2-parameter Weibull distribution. Journal of Statistics Applications & Probability.  (Έγινε αποδεκτό προς δημοσίευση

Α.23 D. Panaretos,   G.  Tzavelas,    M. Vamvakari   and    D. Panagiotakos (2020).  Investigating the repeatability of the extracted factors in relation to the type of rotation used, and the level of random error: a simulation study. Journal of Data Science 18(2):90-404

A.22 G. Tzavelas (2019). A Characterization of the Pareto distribution based on     the Fisher information for censored data under non-regularity conditions. Metrika 82(4) 429-440.

A.21 D. Panaretos,  G. Tzavelas,  M. Vamvakari and D. Panagiotakos (2019). Investigating the role of orthogonal and non-orthogonal rotation in multivariate factor analysis, in regard to the repeatability of the extracted factors: A simulation study. Communication in Statistics-Simulation and Computation 48(7) 2165-2176

 A.20 G. Tzavelas  and  P. Economou (2018).  On  the consequences of model misspecification for biased samples. Statistics and Simulation IWS 8, Vienna, Austria, September 2015. Jurgen Pilz, Dieter Rasch Viatcheslav B. Melas, Karl Moder Editors. Stringer Proceedings in Mathematics & Statistics. 357-369.

A.19 D. Panaretos, G. Tzavelas, M. Vamvakari and D. Panagiotakos (2017). Factor Analysis as a tool for Pattern Recognition in Biomedical Research; a review with application in R software. Journal of Data Science 16, 615-630.

A.18 G. Tzavelas, M. Douli and P.   Economou (2017).  Model misspecification effects   for biased samples. Metrika 80(2) 171-185.

A.17  P. Economou, A. Batsidis and G.  Tzavelas (2016).  Tests of fit for a lognormal    distribution. Journal of Statistical Computation and Simulation86(2) 215-235.

A.16 G. Tzavelas & P. Economou (2015).  Extreme value distributions for biased      samples. Probability in the Engineering and Informational Sciences29 1-14

A.15 P. Economou and G. Tzavelas (2014). Kullback-Leibler divergence measures based tests concerning the biasness in a sample. Statistical Methodology 21, 88-108.

A.14 G. Tzavelas and P. Economou (2014). Characterization properties based on the Fisher information for weighted distributions. Statistics and Probability Letters 84, 54–59

A.13 P. Economou and G. Tzavelas (2013). Sample tests for the detection of size-biased sampling mechanism.  Communication in Statistics- Theory and Methods 42(18), 3280-3295.

A.12 G. Tzavelas and D. Panagiotakos (2013). Statistical inference for the size-biased Weibull distribution. Journal of Statistical Computation and Simulation 83(7) ,1252-1262.

A.11 G. Tzavelas, P. Economou (2012). Characterization Properties of the Lognormal Distribution with the Help of  Divergence Measures.  Statistics and Probability Letters 82, 1837-1840

A.10 G. Tzavelas (2012). A study on the number of solutions of the system of the log-likelihood equations for the 3-parameter Weibull distribution. Applications of Mathematics 57 (5), 531-542

A.9 G. Tzavelas (2011). Pooled estimators for the shape parameter of the 3-parameter gamma distribution (2011) Journal of Statistical Computation and Simulation.  81(19) 1099-1109

 Α.8 G. Tzavelas and A.G. Paliatsos (2009). Sharp lower bounds for the moments of symmetric probability density functions. Far East Journal of Mathematical Sciences32(1), 137-       143.

A.7 G. Tzavelas, (2009). Maximum likelihood parameter estimation in the three-parameter gamma distribution with the use of Mathematica. Journal of Statistical Computation and Simulation. 79 (12), 1457-1466

A.6 G. Tzavelas (2009). Estimation in the three-parameter gamma distribution based on the profile log-likelihood function. Communication in Statistics- Theory and Methods 38(5), 573-583.

A.5 G. Tzavelas (2008). Sufficient conditions for the existence of a solution for the Log-likelihood equations in the three-parameter Gamma distribution. Communication in Statistics: Theory and Methods 37(9), 1371-1382.

A.4 G. Tzavelas and A.G. Paliatsos (2001). Truncated quasi-score function in the 1-dependent and stationary case. Statistics and Probability Letters  53, 1-9.

 Α.3  G. Tzavelas and M. Karamolegos (2001).  Α Characterization  of Morris family of distributions with the help of estimating functions. Journal of Interdisciplinary Mathematics, 4(2-3), 129-137.

A.2 G. Tzavelas (1999). A Characterization of the Normal Family of distribution based on the bias of Maximum Likelihood Estimator. The Australian and New Zealand Journal of Statistics 41(4)431-438.

A.1 G. Tzavelas (1998). A Note on the Uniqueness of  the  Quasi-likelihood Estimators. Statistics and Probability Letters 38, 125-130.

  • Β.  Papers public in Journals related to sciences of Health and Environment

Β.15 D. Panaretos, E. Koloverou, A. C. Dimopoulos,  G. M. Kouli, M. Vamvakari, G. Tzavelas, Chr. Pitsavos, D. B. Panagiotakos (2018). A Comparison of Statistical and Machine-learning techniques in evaluating the association between dietary patterns and 10-year cardiometabolic risk (2002-2012): the ATTICA study. British Journal of Nutrition; 120(3) 326-334

Β.14 D. Panaretos,      G.  Tzavelas,      M. Vamvakari,    D.Β.  Panagiotakos (2017). Repeatability  of  dietary patterns extracted through multivariate statistical methods:  a literature review in methodological issues Int J Food Sci Nutr.  68(4):385-391

Β.13 V. Bountziouka, G. Tzavelas, E. Polychronopoulos, T.C. Constantinidis and  D.B. Panagiotakos (2011). Validity of dietary patterns derived in nutrition surveys using a priori and a posteriori multivariate statistical methods. Int J Food Sci Nutr. 62(6):617-27.

Β.12 G. Tzavelas, G.A. Paliatsos, and T.P. Nastos (2010). Brief communication. Models for exceedances of high thresholds for the precipitation daily totals over Athens, Greece. Natural Hazards and Earth system Sciences 10 105-108

Β.11 D. Sapounzi-Krepia,     V. Raftopoulos,     G. Tzavelas,     M. Psychogiou,      C.C. Callister and Vehvilainen-Julkunen, (2009). Mothers’ experiences of maternity services: Internal consistency and test-retest reliability of the Greek translation of the Kuopio Instrument for Mothers.  Midwifery 25(6), 691-700

Β.10 G. Tzavelas and G.A. Paliatsos (2009). A study of the distribution of the annual extreme daily precipitation totals in Athens Greece.  Fresenius Environmental Bulletin, 18, 5b, 824-830 

Β.9 D. Sapounzi-Krepia, V. Raftopoulos, M. Psychogiou, G. Tzavelas and  Vehvilainen-Julkunen,(2009). Test-retest reliability of the Kuopio instrument for fathers (KIF): a questionnaire to assess fathers’ feelings, experiences and preparation for their wife/partner’s delivery. Midwifery, 25 (4), 366-372

Β.8   M.B. Anthracopoulos, E. Mantzouranis, A.G. Paliatsos, G. Tzavelas, E. Lagona, P. Nikolaidou and KN Priftis (2007). Different effects of sensitization to mites and pollens on asthma symptoms and spirometric indices in children: a population-based cohort study.  Annals of Allergy, Asthma, and Immunology99(2), 122-129.

Β.7   K.N. Priftis, M.B. Anthracopoulos, A. Nikolaou-Papanagiotou, V. Mantziou,               A.G.  Paliatsos, G. Tzavelas,   P. Nikolaidou, and  E. Mantzouranis. (2007). Increased sensitization in urban vs. rural environment: Rural protection or an urban living effect?. Pediatric Allergy and Immunology18(3), 209-216 (DOI: 10.1111/j.1399-3038.2006.00514.x).

Β.6  K.N. Priftis, M.B. Anthracopoulos, A.G. Paliatsos, G. Tzavelas, A. Nikolaou-   Papanagiotou, P. Douridas, P. Nikolaidou, E. Mantzouranis (2007). Different effects of urban and rural environments in the respiratory status of Greek schoolchildren. Respiratory Medicine, 101, 98-106 (doi: 10.1016/

Β.5  Z. Roupa,  V. Raftopoulos, P. Sotiropoulou,  G. Tzavelas, E. Kotrotsiou, T. Paralikas, I. Papathanasiou, H. Sarli and M. Nikas (2005). Assessment of the needs of individuals enrolled in a support program for the elderly. ICUs and Nursing Web Journal, 24, 1-10.

Β.4   A.G. Paliatsos,   P.T. Nastos, G. Tzavelas, D.B. Panagiotakos (2005). Characteristics of precipitation in the Athens area, Greece. Fresenius   Envionmental Bulletin, 14( 5), 422-428.

Β.3  Z. Roupa,  F. Faros,   V. Raftopoulos,  G. Tzavelas,   E. Kotrotsiou, P. Sotiropoulou, E. Karanikola, E. Skifta,  A. Ardavanis,  (2004). Serum CA 125 Combined with Transvaginal Ultrasonography for Ovarian Cancer Screening. In Vivo18, 831-836.

Β.2  E.  Theodosopoulou,   G.   Tzavelas,  E.  Kotrotsiou,  V.    Raftopoulos,  E.  Konstandinou,   N. Anastasiou, (2001). Psychometric Properties of the revised piper fatigue scale in Greek women with breast cancerICUs and Nursing Web Journal Issue 8th, 1-15.

Β.1  E.  Τheodosopoulou,   G. Tzavelas, E.  Kotrotsiou, V.  Raftopoulos,   E. Konstandinou, and E. Andreou (2000). Τhe Polypharmacy of the Third Age in Greece. Epitheorese Klinikes Farmakologias and Farmakokinetikes, International Edition14, 145-150.

G. Tzavelas and F. Vonda (2017) Sampling and Applications  Paraskinio Ed.  Athens.