Tomaž (Tomo) Pisanski (born 24 May 1949 in

Ljubljana Ljubljana (also known by other historical names) is the capital and largest city of Slovenia. It is the country's cultural, educational, economic, political and administrative center. During antiquity, a Roman city called Emona stood in the ar ...

Yugoslavia Yugoslavia (; sh-Latn-Cyrl, separator=" / ", Jugoslavija, Југославија ; sl, Jugoslavija ; mk, Југославија ;; rup, Iugoslavia; hu, Jugoszlávia; rue, label=Pannonian Rusyn, Югославия, translit=Juhoslavija ...

, which is now in

Slovenia Slovenia ( ; sl, Slovenija ), officially the Republic of Slovenia (Slovene: , abbr.: ''RS''), is a country in Central Europe. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, an ...

) is a

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

working mainly in

discrete mathematics Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continuous f ...

and

graph theory In mathematics, graph theory is the study of ''graphs'', which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of '' vertices'' (also called ''nodes'' or ''points'') which are conne ...

. He is considered by many Slovenian mathematicians to be the "father of Slovenian discrete mathematics."

Biography

As a high school student, Pisanski competed in the 1966 and 1967

International Mathematical Olympiad The International Mathematical Olympiad (IMO) is a mathematical olympiad for pre-university students, and is the oldest of the International Science Olympiads. The first IMO was held in Romania in 1959. It has since been held annually, except i ...

s as a member of the Yugoslav team, winning a bronze medal in 1967. He studied at the

University of Ljubljana The University of Ljubljana ( sl, Univerza v Ljubljani, , la, Universitas Labacensis), often referred to as UL, is the oldest and largest university in Slovenia. It has approximately 39,000 enrolled students. History Beginnings Although certain ...

where he obtained a B.Sc, M.Sc and PhD in mathematics. His 1981 PhD thesis in

topological graph theory In mathematics, topological graph theory is a branch of graph theory. It studies the embedding of graphs in surfaces, spatial embeddings of graphs, and graphs as topological spaces. It also studies immersions of graphs. Embedding a graph in ...

was written under the guidance of

Torrence Parsons Torrence Douglas Parsons (1941–1987) was an American mathematician. He worked mainly in graph theory, and is known for introducing a graph-theoretic view of pursuit–evasion problems (Parsons 1976, 1978). He obtained his Ph.D. from Princeto ...

. He also obtained an M.Sc. in

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

from

Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsylvan ...

in 1979. Currently, Pisanski is a professor of

discrete Discrete may refer to: *Discrete particle or quantum in physics, for example in quantum theory * Discrete device, an electronic component with just one circuit element, either passive or active, other than an integrated circuit *Discrete group, a ...

and

computational mathematics Computational mathematics is an area of mathematics devoted to the interaction between mathematics and computer computation.National Science Foundation, Division of Mathematical ScienceProgram description PD 06-888 Computational Mathematics 2006 ...

and Head of the Department of Information Sciences and Technology at

University of Primorska University of Primorska (Slovenian ''Univerza na Primorskem'', Italian ''Università del Litorale'') is by age and size the third university in Slovenia. It is located in Koper, Izola, and Portorož and is named for the Slovenian Littoral region ...

Koper Koper (; it, Capodistria, hr, Kopar) is the fifth largest city in Slovenia. Located in the Istrian region in the southwestern part of the country, approximately five kilometres () south of the border with Italy and 20 kilometres () from Triest ...

. In addition, he is a professor at the

Faculty of Mathematics and Physics (FMF). He has been a member of the Institute of Mathematics, Physics and Mechanics (IMFM) in Ljubljana since 1980, and the leader of several IMFM research projects. In 1991 he established the Department of Theoretical Computer Science at IMFM, of which he has served as both head and deputy head. He has taught undergraduate and graduate courses in mathematics and computer science at the

University of Zagreb The University of Zagreb ( hr, Sveučilište u Zagrebu, ; la, Universitas Studiorum Zagrabiensis) is the largest Croatian university and the oldest continuously operating university in the area covering Central Europe south of Vienna and all of ...

University of Udine The University of Udine (Italian ''Università degli Studi di Udine'') is a university in the city of Udine, Italy. It was founded in 1978 as part of the reconstruction plan of Friuli after the earthquake in 1976. Its aim was to provide the Friul ...

University of Leoben The University of Leoben (German: ''Montanuniversität Leoben'') in Austria is the country's university for mining, metallurgy and materials. It was founded on 4 November 1840 as the ''Steiermärkisch-Ständische Montanlehranstalt'' in Vordernbe ...

California State University, Chico California State University, Chico, or commonly, Chico State, is a public university in Chico, California. Founded in 1887, it is the second oldest campus in the California State University system. As of the fall 2020 semester, the university had ...

Simon Fraser University Simon Fraser University (SFU) is a public research university in British Columbia, Canada, with three campuses, all in Greater Vancouver: Burnaby (main campus), Surrey, and Vancouver. The main Burnaby campus on Burnaby Mountain, located from ...

University of Auckland , mottoeng = By natural ability and hard work , established = 1883; years ago , endowment = NZD $293 million (31 December 2021) , budget = NZD $1.281 billion (31 December 2021) , chancellor = Cecilia Tarrant , vice_chancellor = Dawn F ...

and

Colgate University Colgate University is a private liberal arts college in Hamilton, New York. The college was founded in 1819 as the Baptist Education Society of the State of New York and operated under that name until 1823, when it was renamed Hamilton Theologi ...

. Pisanski has been an adviser for M.Sc and PhD students in both mathematics and computer science. Notable students include John Shawe-Taylor (B.Sc in Ljubljana),

Vladimir Batagelj Vladimir Batagelj (born June 14, 1948 in Idrija, Yugoslavia) is a Slovenian mathematician and an emeritus professor of mathematics at the University of Ljubljana. He is known for his work in discrete mathematics and combinatorial optimization, p ...

Bojan Mohar Bojan Mohar (born September 21, 1956) is a Slovenian and Canadian mathematician, working in graph theory. He is a professor of mathematics at the University of Ljubljana and the holder of a Canada Research Chair in graph theory at Simon Fraser Unive ...

Sandi Klavžar Sandi Klavžar (born 5 February 1962) is a Slovenian mathematician working in the area of graph theory and its applications. He is a professor of mathematics at the University of Ljubljana. Education Klavžar received his Ph.D. from the University ...

, and Sandra Sattolo (M.Sc in Udine).

Research

Pisanski’s research interests span several areas of discrete and computational mathematics, including combinatorial configurations,

abstract polytope In mathematics, an abstract polytope is an algebraic partially ordered set which captures the dyadic property of a traditional polytope without specifying purely geometric properties such as points and lines. A geometric polytope is said to be ...

s, maps on surfaces,

chemical graph theory Chemical graph theory is the topology branch of mathematical chemistry which applies graph theory to mathematical modelling of chemical phenomena. The pioneers of chemical graph theory are Alexandru Balaban, Ante Graovac, Iván Gutman, Haruo Hosoy ...

, and the history of mathematics and science. In 1980 he calculated the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of the

Cartesian product In mathematics, specifically set theory, the Cartesian product of two sets ''A'' and ''B'', denoted ''A''×''B'', is the set of all ordered pairs where ''a'' is in ''A'' and ''b'' is in ''B''. In terms of set-builder notation, that is : A\ti ...

of any pair of connected, bipartite, ''d''-valent graphs using a method that was later called the ''White–Pisanski method''. In 1982

and Pisanski proved that the

of a

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

and a cycle is

Hamiltonian Hamiltonian may refer to: * Hamiltonian mechanics, a function that represents the total energy of a system * Hamiltonian (quantum mechanics), an operator corresponding to the total energy of that system ** Dyall Hamiltonian, a modified Hamiltonian ...

if and only if no degree of the tree exceeds the length of the cycle. They also proposed a conjecture concerning ''cyclic Hamiltonicity'' of graphs. Their conjecture was proved in 2005. With

Brigitte Servatius Brigitte Irma Servatius (born 1954) is a mathematician specializing in matroids and structural rigidity. She is a professor of mathematics at Worcester Polytechnic Institute, and has been the editor-in-chief of the '' Pi Mu Epsilon Journal'' since ...

he is the co-author of the book ''Configurations from a Graphical Viewpoint'' (2013). .

Selected publications

* Pisanski, T. Genus of Cartesian products of regular bipartite graphs,

Journal of Graph Theory The ''Journal of Graph Theory'' is a peer-reviewed mathematics journal specializing in graph theory and related areas, such as structural results about graphs, graph algorithms with theoretical emphasis, and discrete optimization on graphs. The s ...

4 (1), 1980, 31-42
doi:10.1002/jgt.3190040105
* Graovac, A., T. Pisanski. On the Wiener index of a graph, Journal of Mathematical Chemistry 8 (1),1991, 53-62
doi:10.1007/BF01166923
* Boben, M., B. Grunbaum, T. Pisanski, A. Zitnik, Small triangle-free configurations of points and lines,

Discrete & Computational Geometry '' Discrete & Computational Geometry'' is a peer-reviewed mathematics journal published quarterly by Springer. Founded in 1986 by Jacob E. Goodman and Richard M. Pollack, the journal publishes articles on discrete geometry and computational geom ...

35 (3), 2006, 405-427
doi:10.1007/s00454-005-1224-9
* Conder, M., I. Hubard, T. Pisanski. Constructions for chiral polytopes, Journal of the London Mathematical Society 77 (1), 2007, 115-129
doi:10.1112/jlms/jdm093
* Pisanski, T. A classification of cubic bicirculants,

Discrete Mathematics Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continuous f ...

307 (3-5), 2007, 567-578
doi:10.1016/j.disc.2005.09.053

Professional life

From 1998-1999, Pisanski was chairman of the

Society of Mathematicians, Physicists and Astronomers of Slovenia The Society of Mathematicians, Physicists and Astronomers of Slovenia ( Slovene: Društvo matematikov, fizikov in astronomov Slovenije, DMFA) is the main Slovene society in the field of mathematics, physics and astronomy. The Society is occupied ...

(DMFA Slovenije); he was appointed an honorary member in 2015. He is a founding member of the

International Academy of Mathematical Chemistry The International Academy of Mathematical Chemistry (IAMC) was founded in Dubrovnik (Croatia) in 2005 by Milan Randić. It is an organization for chemistry and mathematics avocation, and its predecessors have been around since the 1930s. The Acad ...

, serving as its vice president from 2007 to 2011. In 2008, together with

Dragan Marušič Dragan Marušič (born 1953, Koper, Slovenia) is a Slovene mathematician. Marušič obtained his BSc in technical mathematics from the University of Ljubljana in 1976, and his PhD from the University of Reading in 1981 under the supervision of C ...

, he founded ''

Ars Mathematica Contemporanea ''Ars Mathematica Contemporanea'' is a quarterly peer-reviewed scientific journal covering discrete mathematics in connection with other branches of mathematics. It is published by the University of Primorska together with the Society of Mathemati ...

,'' the first international mathematical journal to be published in Slovenia. In 2012 he was elected to the

Academia Europaea The Academia Europaea is a pan-European Academy of Humanities, Letters, Law, and Sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europea ...

. He is currently president of the Slovenian Discrete and Applied Mathematics Society (SDAMS), the first Eastern European mathematical society not wholly devoted to theoretical mathematics to be accepted as a full member of the

European Mathematical Society The European Mathematical Society (EMS) is a European organization dedicated to the development of mathematics in Europe. Its members are different mathematical societies in Europe, academic institutions and individual mathematicians. The current ...

(EMS).

Awards and honors

In 2005, Pisanski was decorated with the Order of Merit (Slovenia), and in 2015 he received the Zois award for exceptional contributions to discrete mathematics and its applications. In 2016, he received the

Donald Michie Donald Michie (; 11 November 1923 – 7 July 2007) was a British researcher in artificial intelligence. During World War II, Michie worked for the Government Code and Cypher School at Bletchley Park, contributing to the effort to solve " Tunny ...

and

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical com ...

Prize for lifetime achievements in

Information Science Information science (also known as information studies) is an academic field which is primarily concerned with analysis, collection, Categorization, classification, manipulation, storage, information retrieval, retrieval, movement, dissemin ...

in Slovenia.

References

External links

Pisanski's CV
* *

* ttp://en.ias.si/membership/regular-and-associate-members/ Slovenian Academy of Engineering - List of Membersbr>Images of Knowledge: Tomaž Pisanski - RTV radio interview8th European Congress of Mathematics websiteMaps ∩ Configurations ∩ Polytopes ∩ Molecules ⊆ Graphs: The mathematics of Tomaž Pisanski on the occasion of his 70th birthdayArs Mathematica Contemporanea websiteSlovenian Society for Discrete and Applied Mathematics (SDAMS) website
{{DEFAULTSORT:Pisanski, Tomaz 1949 births 20th-century Slovenian mathematicians 21st-century Slovenian mathematicians Graph theorists Living people Pennsylvania State University alumni Slovenian computer scientists Scientists from Ljubljana Mathematical chemistry University of Ljubljana alumni Members of Academia Europaea Academic staff of the University of Ljubljana Academic staff of the University of Primorska Academic staff of the University of Zagreb Academic staff of Montanuniversität Leoben California State University, Chico faculty Academic staff of Simon Fraser University Academic staff of the University of Auckland Colgate University faculty International Mathematical Olympiad participants Computational chemists Yugoslav mathematicians