First Name

Radu

Last Name

Buzatu

Scientific degree

doctor

Academic title/position

lecturer

Department

Mathematics Department

Education

Moldova State University, Faculty of Mathematics and Computer Science

2013 – 2017

PhD in Mathematical Sciences. Thesis: “Covers of Undirected Graphs by Convex Sets”. Operational Research and Cybernetics. Advisor: Sergiu Cataranciuc, Dr. habil., Professor

2011 – 2013

Master in Applied Mathematics. Statistical Analysis of Economic Processes

2008 – 2011

Bachelor in Computer Science. Information Management

Professional experience

2013 – present

Researcher, Moldova State University, Faculty of Mathematics and Computer Science,

Mathematical Modeling and Optimization Laboratory,

Results:

- Proved that the problem of deciding whether a graph can be covered (partitioned) by a given number of convex sets is NP-complete;
- Identified a series of graphs classes for which there exists a cover (partition) by a given number of convex sets;
- Established conditions for the existence of a graph with the given minimum number of convex sets and minimum (maximum) number of nontrivial convex sets, which cover or partition a graph. Proved that it is NP-hard to determine these invariants for a graph;
- Proposed a polynomial algorithm that determines whether a tree can be partitioned into a given number of nontrivial convex sets, and showed that it can be verified in polynomial time whether a graph can be covered by an arbitrary number of nontrivial convex sets;
- Developed a library of algorithms by using C# language for decision whether a graph can be covered (partitioned) by convex sets, which may be applied to facility location problem;
- Developed a binary linear programming model for optimizing administrative-territorial structure of the state that takes into consideration population, economic development, ethnic structure, territorial and road connectivity;
- Developed an information system by using MATLAB for simulations of optimal scenarios of administrative-territorial organization in real time;
- Developed a technique based on mixed integer programming for detecting gerrymandering in parallel voting systems.

Didactic activity

2017 – present

Moldova State University, Faculty of Mathematics and Computer Science,

Department of Mathematics,

Courses:

- Discrete Mathematics;
- Combinatorial Optimization;
- Linear programming;
- Graph Theory;
- Mathematical Software;
- Information and Communication Technology.

Scientific activity

List of scientific papers and books

- Buzatu R., Cataranciuc S.,
*Convex graph covers.* - Buzatu R.,
*Covers of graphs by two convex sets.* - Buzatu R.,
*Minimum convex cover of special nonoriented graphs*. - Buzatu R., Cataranciuc S.,
*Nontrivial convex covers of trees.* - Buzatu R., Cataranciuc S.,
*On nontrivial covers and partitions of graphs by convex sets.* - Buzatu R., Rabei C., Roșcovan M.,
*A mathematical model for optimization of administrative-territorial organization of the Republic of Moldova*, Studia Universitatis Moldaviae, Exact and Economic Science (ISSN:1857-2073), Nr.2(112), 2018, p.164-170. - Cataranciuc S., Buzatu R., Tkacenko A., Hâncu B., Novac L., Pațiuc V., Rîbacova G., Cucu I.
*Disctrete structures and optimization problems*. Monograph. Chapter II. Chișinău, (ISBN 978-9975-149-44-0), 2019, 454 p; - Buzatu R.,
*Binary linear programming approach for graph convex covering problems.* - Buzatu R.,
*On the computational complexity of optimization convex covering problems of graphs.* - Mandric I., Roșca I., Buzatu R.,
*Gerrymandering and fair districting in parallel voting systems*. arXiv:2002.06849v1, 2020, 23 p. - Buzatu R.,
*Maximum nontrivial convex cover number of join and corona of graphs*. Bulletin of Academy of Sciences of Republic of Moldova, Mathematics, in press.

List of scientific conferences

- Buzatu R., Poștaru A.,
*Genetic algorithms. Some applications**.* - Buzatu R., Iurco D.,
*Knowledge interchange between semantic technologies in building of intelligent interface**s.* - Andrieș I., Buzatu R.,
*Tridimentional spectral color model as an one to one transformation from rgb color space.* - Buzatu R.,
*Convex covers of undirected graph**.* - Buzatu R.,
*NP-completeness of graph convex cover problems.* - Andrieș I., Buzatu R.,
*Ordering colors of the hvs color model in an one-dimentional physical spectrum.* - Buzatu R.,
*Nontrivial convex 2-covers of simple connected graphs*. Proceedings of the 23rd Conference on Applied and Industrial Mathematics (CAIM-2015), September 17 - 20, 2015, Suceava, Romania, p. 36-37; - Buzatu R.,
*Convex**2-covers of nonoriented graphs.*Proceedings of the International Conference „Integration through Research and Innovation”, Moldova State University, November 10 - 11, 2015, Chișinău, Moldova, p. 177 - 180; - Buzatu R., Cataranciuc S.,
*Cover of a nonoriented graph by nontrivial convex sets*. - Buzatu R., Cataranciuc S.,
*Minimum convex covers of some graph operations.* - Buzatu R.,
*Nontrivial convex partition of a tree*. Proceedings of the International Conference “Mathematics & Information Technologies: Research and Education” (MITRE – 2016), June 23 - 26, 2016, Chișinău, Moldova, p. 12 - 13; - Buzatu R.,
*Nontrivial convex cover of a tree.* - Buzatu R.,
*Maximum nontrivial convex cover of a tree*. Proceedings of the Fourth Conference of Mathematical Society of the Republic of Moldova, June 28 - July 2, 2017, Chișinău, Moldova, p. 365 - 368; - Buzatu R.,
*Algorithms for determining nontrivial convex covers of graphs**.* - Buzatu R.,
*Partitioning a graph into convex sets*.*Some applications.*Proceedings of the Annual Conference of the Romanian Mathematical Society, May 25 - 26, 2018, Corabia, Romania; - Buzatu R.,
*A binary linear programming model for minimum convex partition of a graph.*Proceedings of the International Summer Mathematical School in Memoriam V. A. Plotnikov, June 11 - 16, 2018, Odessa, Ukraine, p. 89; - Buzatu R.,
*BLP modeling of the convex cover problem of a graph*. Proceedings of the International Scientific Conference “Modern Problems of Mathematics and Its Application in Natural Sciences and Information Technologies”, September 17 - 19, 2018, Chernivtsi, Ukraine, p. 124; - Buzatu R.,
*Improvement of the administrative-territorial structure using mixed integer linear programming.* - Buzatu R.,
*A**formulation of convex covering problem of graphs as a linear programming problem.* - Buzatu R., Cataranciuc S.,
*On the difficulty of determining the maximum nontrivial convex cover number of a graph**.* - Buzatu R.,
*Optimization problems of general convex covering problem of graphs*. Proceedings of the International Conference “Mathematics & Information Technologies: Research and Education” (MITRE – 2019), June 24 - 26, 2019, Chișinău, Moldova, p. 13; - Buzatu R.,
*Graph partitioning problems and their applications in socio-economic fields*. Proceedings of the Ninth Conference of Romanian Mathematicians, June 28 - July 3, 2019, Galați, Romania, p. 18; - Buzatu R.,
*On**the maximum nontrivial convex cover number of the join of graphs.*Proceedings of the Fifth Conference of the Mathematical Society of the Republic of Moldova, September 28 – October 1, 2019, Chișinău, Moldova.

Other

- Project 11.817.08.49A (institutional project). Research theme: “Modern methodologies in software development” (2011-2014);
- Project 1C/2012 (bilateral projects with „Est Computer” company). Research theme: “Web 3.0 development” (2012);
- Project 15.820.18.02.03/B (bilateral projects with Belarus). Research theme: “Efficient models and algorithms for solving optimization problems on discrete structures” (2015-2016);
- Project 16.80012.02.03F (project for young scientist). Research theme: “Stochastic optimization algorithms” (2016-2018);
- Project 2017.3506.7-001.00 (Government project with GIZ cooperation). Research theme: “Support to Territorial-Administrative Reform in the Republic of Moldova” (2018);
- Project 15.817.02.37A (institutional project). Research theme: “Mathematical modeling and advanced computing in applied problems” (2015-2019);
- Project 20.80009.5007.13 (institutional project “Institute of Mathematics and Computer Science”). Research theme: “Deterministic and stochastic methods for solving optimization and control problems” (2020).