Dr. Maroussia Nikiforova SlavtchovaBojkova

 Professional Experience
 Postdoc Specializations and Visiting Positions
 Teaching activities
 Professional and Software Skills
 Knowledge of foreign languages
 Participation in international conferences
 List of Selected Publications
 Recent major accomplishments
 Reviewing and refereeing work
 Membership in Professional Societies
Professional Experience
 2004  Present: Associate Professor, Faculty of Mathematics and Informatics, Department of Operational Research, Probability and Statistics, Sofia University.
 2001  2003: Adjunct Associate Professor, Faculty of Mathematics and Informatics, Department of Operational Research, Probability and Statistics, Faculty of Mathematics and Informatics, Sofia University.
 1990  2000: Adjunct Assistant Professor, Department of Operational Research, Probability and Statistics, Faculty of Mathematics and Informatics, Sofia University.
 2001  Present: Senior Research Associate at the Department of Probability and Statistics, Institute of Mathematics and Informatics, Bulgarian Academy of Sciences.
 1989  2000: Junior Researcher at the Department of Probability and Statistics, Institute of Mathematics and Informatics, Bulgarian Academy of Sciences.
Postdoc Specializations and Visiting Positions
 University of Extremadura, Badajoz, Spain. Branching processes in epidemiological context. Scientist in charge: Prof. Dr M. Gonzales 19/09  30/10/2007.
 Westfälishe WilhelmsUniversität Münster, Münster, Germany. Theoretical investigations of branching processes with two types of immigration – Central limit theorem and Law of large numbers. Scientist in charge: Prof. Dr Gerold Alsmeyer 01/10 – 30/12/2003.
 Westfälishe WilhelmsUniversität Münster, Münster, Germany. Preparing proposal for DFG joint research project on the limit problems for branching processes treated by renewal approach. Scientist in charge: Prof. Dr Gerold Alsmeyer 01/10 – 31/10/2002.
 University of Extremadura, Badajoz, Spain. Statistical Inferences for a special class of branching processes with immigration – nonparametric estimates and simulations. Scientist in charge: Prof. Dr M. Molina 01/0930/09/2002.
 Vrije Universiteit Brussel, Brussel, Belgium. The purpose of the research work was to treat some real world problems related to population and repopulation experiments by use of branching processes with immigration. Tutor: Prof. F. Thomas Bruss, 3 months, 1996, Grant from Flemish Office for Scientific, Technical and Cultural Affairs, Belgium.
Teaching Activities
Lectures at the Faculty of Mathematics and Informatics and the Faculty of Biology of Sofia University, at the University of Mining and Geology and at the New Bulgarian University (Informatics Department) for undergraduate, graduate students and MSc degree students.
(I) Courses:
Probability and Statistics – basic and advanced;
Stochastic Processes – BSc and MSc degree;
Branching Processes – MSc degree;
Decision making theory (Bayesian approach) – MSc degree;
Probability and Statistics for Engineers;
Probability and Statistics for Biologists;
(II) Supervision of three M.Sc. students
(III) Leader of the M.Sc. Programme
Probability and Statistics at the Department of Probability, Operational Research and Statistics of the Faculty of Mathematics and Informatics of Sofia University.
Professional and Software Skills
Deep knowledge and experience in developing mathematical models for branching
stochastic systems with different types of migration
Knowledge in numerical computation and simulation methods for branching
processes
Knowledge in MATLAB and MAPLE packages.
Knowledge of Foreign Languages
Fluent in English and very good in Russian and good in French and Deutsch.
Participation in International Conferences
 2007: Symposium on Stochastic Modelling in Population Dynamics, CIRM, Luminy, France
 2006: Second International Congress on Mathematics, MICOM2006, Cyprus
 2006: XIIth International Conference on Probability and Statistics, Sozopol, Bulgaria
 2005: Symposium on Branching Processes, Goteborg, Sweden
 2004: XIth International Conference on Probability and Statistics, Sozopol, Bulgaria
 2003: First International Conference on Mathematics and Informatics for Industry, MII 2003, Thessaloniki, Greece,
 2003: Xth International Conference on Probability and Statistics, Sozopol, Bulgaria
 2002: Seminar on Stability, Varna, Bulgaria
 2001: Second International Conference on Deterministic and Stochastic Modelling of Biointeraction, DESTOBIO'2000, West Lafayette, Indiana, USA
 2000: Workshop on Biostatistics and Bioinformatics, Goteborg, Sweden
 1998: Alcala First International Conference on Mathematical Ecology, Alcala de Henares (Madrid), Spain
 1997: First International Conference on Deterministic and Stochastic Modelling of Biointeraction, Sofia, Bulgaria
 1995: Athen's Conf. on Appl. Probab. and Time Ser. Anal., Greece
 1993: First World Congress on Branching Processes, Varna, Bulgaria
 1991: 7th European Meeting of Young Statisticians, Oberwolfach, Germany
List of Selected Publications
Papers in Refereed Journals
 M. Gonzalez, R. Martinez, M. SlavtchovaBojkova (2008): Stochastic monotonicity and continuity properties of the extinction time of BellmanHarris branching processes: an application to epidemic modelling. Submitted in Adv. Appl. Prob.
 M. SlavtchovaBojkova (2007) :From regeneration to escape the extinction in population experiments, Mathematica Balkanica. New Series Vol. 21, Fasc. 34, 289300.
 R. Martinez, M. SlavtchovaBojkova (2005): Comparison between Numerical and Simulation Method for Agedependent Branching Models with Immigration, Pliska, (Studia Mathematica Bulgarica), 17, 147155.
 G. Alsmeyer, M. SlavtchovaBojkova (2005): Limit Theorems for Subcritical Agedependent Branching Processes with Two Types of Immigration. Stochastic Models, 21(1), 133147.
 M. SlavtchovaBojkova, P. BeckerKern, K. Mitov, (2004): Total Progeny in a Subcritical Branching Processes with Statedependent Immigration. Pliska, (Studia Mathematica Bulgarica), 16, 229245.
 M. SlavtchovaBojkova, N. M. Yanev (2000) Limit Theorems for AgeDependent Branching Processes with Emigration. Comptes Rendus de l'Academie Bulgare des Sciences, 54, No 1.
 M. SlavtchovaBojkova (2000): Computation of Waiting Time to Successful Experiment Using Agedependent Branching Model. Ecological Modelling, 133, 125131.
 F. T. Bruss, M. SlavtchovaBojkova (1999): On Waiting Times to Populate an Environment and a question of Statistical Inference. Journal of Applied Probability, 36, 261267.
 M. SlavtchovaBojkova, N. M. Yanev (1994): Noncritical Branching Processes with Two Types of Statedependent Immigration, Comptes Rendus de l'Academie Bulgare des Sciences, 47, 1316.
 M. SlavtchovaBojkova (1991): Limit Theorems for Multitype BellmanHarris Branching Processes with Statedependent Immigration. Serdica, (Bulg. Math. Publ.), 17, 144156.
 M. SlavtchovaBojkova, N. M. Yanev (1991): Noncritical BellmanHarris Branching Processes with Statedependent Immigration. Serdica (Bulg. Math. Publ.), 17, 6779.
 M. SlavtchovaBojkova, N. M. Yanev (1990): Convergence in Distribution of Supercritical BellmanHarris Branching Processes with Statedependent Immigration. Math.Balk. New ser, 4, 3542.
 M. SlavtchovaBojkova, N. M. Yanev (1988): Limit Theorems for BellmanHarris Branching Processes with Statedependent Immigration. Comptes Rendus de l'Academie Bulgare des Sciences, 41, 2733.
Papers in Conference Proceedings
 M. SlavtchovaBojkova (2007): Education in Stochastics/Statistics – A Compulsory Part from the European Culture (Invited talk). Proceedings of the Thirty Sixth Spring Conference, Bulgaria, 102108.
 M. SlavtchovaBojkova (2003): A Stochastic Policy in purifying wasted industrial water using branching model, Proc. of the First International Conference on Mathematics and Informatics for Industry, 1416 April, Thessaloniki, 335342.
 M. SlavtchovaBojkova (2002): On the Subcritical Agedependent Branching Processes with Two Types of Immigration. Mathematics and Mathematical Education, Proceedings of the Thirty First Spring Conference, Borovets, Bulgaria, April 36, 187191.
 M. SlavtchovaBojkova, N. M. Yanev (2001): Subcritical Agedependent Branching Processes with Emigration. Mathematics and Mathematical Education, Proceedings of the Thirtieth Spring Conference, Borovets, Bulgaria, April 811, 281288.
 M. SlavtchovaBojkova, N. M. Yanev (1997): Agedependent branching processes with emigration and population dynamics. In: "Bulletin of the International Statistical Institute", 51st Session, Contributed Papers, 557558.
 M. SlavtchovaBojkova (1996): Multitype Agedependent Branching Processes with Statedependent Immigration, Proceedings of the Athen's Conference on Applied Probability and Time Series Analysis, Ed. C.C. Heyde, Yu. V. Prohorov, R. Pyke, S. T. Rachev , Lecture Notes in Statistics, 114, 192205, Springer Verlag, New York.
 M. SlavtchovaBojkova, N. M. Yanev (1995): Agedependent Branching Processes with Statedependent Immigration, Proceedings of the First World Congress on Branching Processes, Ed. C.C. Heyde, Lecture Notes in Statistics, 99, 7789, Springer Verlag, New York.
 M. SlavtchovaBojkova, N. M. Yanev (1987): Supercritical Branching Processes with Random Migration Stopped at Zero. Mathematics and Mathematical Education, Proceedings of the Sixteenth Spring Conference, Sunny Beach, Bulgaria, April 610, 538544.
 M. SlavtchovaBojkova, N. M. Yanev (1985): Limit Theorems for Supercritical Migration Branching Processes. Mathematics and Mathematical Education, Proceedings of the Fourteenth Spring Conference, Sunny Beach, Bulgaria, April 69, 590593.
Books
 M. SlavtchovaBojkova, Yanev, N. (2007) Branching Stochastic Processes, University press ”St. Kl. Ohridski”, Sofia, p. 107.
 M. SlavtchovaBojkova (2002) Lecture Notes on Stochastic Processes, electronic version, Lecture Notes
Recent Major Accomplishments
 The ongoing research is concerned with agedependent (BellmanHarris) and Sevast'yanov's branching process, describing outbreaks of an infectious disease with incubation period. The main goal is to define the optimal proportion of susceptible individuals that has to be vaccinated in order to eliminate the disease. To this end the properties of the time to extinction of an infection, depending on the proportion of the immune individuals into the population are studied. From these results a vaccination policy based on the mean of the infection survival time is suggested. A simulationbased method to determine the optimal vaccination level is provided and as an illustration the data from outbreaks of avian influenza spreading in Vietnam at the end of 2006 has been analyzed.
 For the classical subcritical agedependent branching process the effect of the following two types of immigration patterns is studied. At a sequence of renewal epochs a random number of immigrants enters the population. Each subpopulation originating from one of these immigrants is refreshed by new immigrants and their offspring whenever it dies out, possibly after an additional delay period. This is the BellmanHarris branching process with immigration at zero and immigration of renewal type. We prove strong law of large numbers and a central limit theorem for such processes. Similar conclusions are obtained for their discretetime counterparts, called GaltonWatson processes with immigration at zero and immigration of renewal type. Our approach is based on the theory of regenerative processes, renewal theory and occupation measures and is quite different from those in earlier related works using analytic tools.
 New computational approach of treating the socalled “waiting time to the successful experiment” by branching processes is developed and gives rise to studying some proper characteristics of the processes on the condition of extinction.
 A code “SIMULATION SYSTEM for branching processes” is developed. No programming is necessary and all input data can be entered in userfriendly dialog boxes and graphics and (numerical) results can be easily and quickly obtained. The results can be stored in the Database table and may be analyzed easily. The code can be used for actual design, prediction and estimation of the parameters of different classes of branching processes. The SIMULATION SYSTEM is a simple professional tool to be used by biologists, engineers and decisionmakers for simulation of the processes which could appear to be suitable for modelling of some real world problems related to population and repopulation experiments, for example.
Reviewing and Refereeing Work
 Serdica, Bulgaricae Mathematicae Publicationes
 Stochastic Models, Communications in Statistics
 Zentralblatt fur Matematik
 Mathematical Reviews
Membership in Professional Societies
 Union of Bulgarian Mathematicians (since 1982)
 Bulgarian Statistical Society (since 1991)
 American Mathematical Society (since 1999)
 International Biometric Society (since 2008)