Membros > Antigo Pós-doutoral

Erkko Lehtonen

Morada Institucional

Faculdade de Ciências da Universidade de Lisboa
Av. Prof. Gama Pinto, 2
1649-003 LISBOA


Telefone: +351 21 7904714 | Email: erkko@campus.ul.pt | Web: ernst-schroeder.uni.lu/lehtonen/

Posição

Faculdade de Ciências, Universidade de Lisboa

Área

Álgebra

Área Principal

Álgebra Universal, Reticulados

Outra Área

Combinatória

Qualificações

  • Doutoramento, Matemática, Tampere University of Technology, Finlândia, 2007
  • Mestrado, Matemática, Tampere University of Technology, Finlândia, 1998

Publicações

Artigos em Revistas Internacionais

Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2015) On equational definability of function classes. J. Mult.-Valued Logic Soft Comput.: 24, 203–222.
Lehtonen, Erkko; Pilitowska, Agata (2015) Entropicity and generalized entropic property in idempotent n-semigroups. Semigroup Forum: 91, 260–281.
Couceiro, Miguel; Lehtonen, Erkko; Schölzel, Karsten (2015) A complete classification of equational classes of threshold functions included in clones. RAIRO Operations Research: 49, 39–66.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2015) A survey on the arity gap. Journal of Multiple-Valued Logic and Soft Computing: 24, 223–249.
Couceiro, Miguel; Lehtonen, Erkko; Schölzel, Karsten (2015) Hypomorphic Sperner systems and non-reconstructible functions. Order: 32, 255–292.
Lehtonen, Erkko (2015) On functions with a unique identification minor. Order.
Couceiro, Miguel; Lehtonen, Erkko; Schölzel, Karsten (2015) Set-reconstructibility of Post classes. Discrete Applied Mathematics: 187, 12–18.
Lehtonen, Erkko; Pilitowska, Agata (2014) Generalized entropy in expanded semigroups and in algebras with neutral element. Semigroup Forum: 88(3), 702–714.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2014) Additive decomposition schemes for polynomial functions over fields. Novi Sad J. Math.: 44(2), 89–105.
Lehtonen, Erkko (2014) Totally symmetric functions are reconstructible from identification minors. The Electronic Journal of Combinatorics: 21(2), #P2.6.
Lehtonen, Erkko; Marichal, Jean-Luc; Teheux, Bruno (2014) Associative string functions. Asian-Eur. J. Math.: 7(4), 1450059, 18 pp..
Lehtonen, Erkko (2014) Reconstructing multisets over commutative groupoids and affine functions over nonassociative semirings. International Journal of Algebra and Computation: 24(1), 11-31.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2013) Additive decomposability of functions over abelian groups. International Journal of Algebra and Computation: 23, 643-662.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2013) Parametrized arity gap. Order: 30, 557-572.
Couceiro, Miguel; Lehtonen, Erkko (2012) Galois theory for sets of operations closed under permutation, cylindrification, and composition. Algebra Universalis: 67(3), 273-297.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2012) The arity gap of order-preserving functions and extensions of pseudo-Boolean functions. Discrete Applied Mathematics: 160(4-5), 383-390.
Behrisch, Mike; Couceiro, Miguel; Kearnes, Keith A.; Lehtonen, Erkko; Szendrei, Ágnes (2012) Commuting polynomial operations of distributive lattices. Order: 29(2), 245-269.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2012) Decompositions of functions based on arity gap. Discrete Mathematics: 312(2), 238-247.
Lehtonen, Erkko; Szendrei, Ágnes (2011) Clones with finitely many relative R-classes. Algebra Universalis: 65, 109-159.
Kwuida, Léonard; Lehtonen, Erkko (2011) On the homomorphism order of labeled posets. Order: 28, 251-265.
Couceiro, Miguel; Lehtonen, Erkko (2011) Self-commuting lattice polynomial functions on chains. Aequationes mathematicae: 81(3), 263-278.
Foldes, Stephan; Lehtonen, Erkko (2010) Column-partitioned matrices over rings without invertible transversal submatrices. Ars Combinatoria: 97, 33-39.
Lehtonen, Erkko; Szendrei, Ágnes (2010) The submaximal clones on the three-element set with finitely many relative R-classes. Discussiones Mathematicae - General Algebra and Applications: 30(1), 7-33.
Lehtonen, Erkko (2010) Closed classes of functions, generalized constraints, and clusters. Algebra Universalis: 63(2-3), 203-234.
Lehtonen, Erkko (2010) A note on minors determined by clones of semilattices. Novi Sad Journal of Mathematics: 40(3), 75-81.
Lehtonen, Erkko; Nešetril, Jaroslav (2010) Minors of Boolean functions with respect to clique functions and hypergraph homomorphisms. European Journal of Combinatorics: 31(8), 1981-1995.
Lehtonen, Erkko (2010) Characterization of preclones by matrix collections. Asian-European Journal of Mathematics: 3(3), 457-473.
Couceiro, Miguel; Lehtonen, Erkko (2009) Generalizations of Swierczkowski's lemma and the arity gap of finite functions. Discrete Mathematics: 309(20), 5905-5912.
Lehtonen, Erkko; Szendrei, Ágnes (2009) Equivalence of operations with respect to discriminator clones. Discrete Mathematics: 309(4), 673-685.
Lehtonen, Erkko (2008) Labeled posets are universal. European J. Combin.: 29, 493-506.
Couceiro, Miguel; Lehtonen, Erkko (2007) On the effect of variable identification on the essential arity of functions on finite sets. Int. J. Found. Comput. Sci.: 18, 975-986.
Couceiro, Miguel; Foldes, Stephan; Lehtonen, Erkko (2006) Composition of Post classes and normal forms of Boolean functions. Discrete Math.: 306, 3223-3243.
Lehtonen, Erkko (2006) Descending chains and antichains of the unary, linear, and monotone subfunction relations. Order: 23, 129-142.

Artigos ou Capítulos em Livros Editados

Couceiro, Miguel; Lehtonen, Erkko; Schölzel, Karsten (2013) Sur des classes de fonctions à seuil caractérisables par des contraintes relationnelles — On classes of threshold functions characterizable by relational constraints. Actes des 22èmes rencontres francophones sur la Logique Floue et ses Applications (LFA 2013), Université de Reims Champagne-Ardenne, 145-152.
Lehtonen, Erkko; Szendrei, Ágnes (2012) Partial orders induced by quasilinear clones. Proceedings of the Salzburg Conference 2011 (AAA81), Verlag Johannes Heyn, Klagenfurt, 51-84.
Couceiro, Miguel; Lehtonen, Erkko; Marichal, Jean-Luc; Waldhauser, Tamás (2011) An algorithm for producing median formulas for Boolean functions. Proceedings of the Reed–Muller 2011 Workshop, Tampere International Center for Signal Processing (TICSP), 49-54.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2011) On the arity gap of aggregation functions. Decision Theory: Qualitative and Quantitative Approaches, Johannes Kepler Universität, Linz, 25–28.
Couceiro, Miguel; Lehtonen, Erkko (2010) The arity gap of polynomial functions over bounded distributive lattices. Proceedings of the 40th IEEE International Symposium on Multiple-Valued Logic (ISMVL 2010), IEEE Computer Society, Los Alamitos, 113-116.
Couceiro, Miguel; Lehtonen, Erkko (2010) Explicit descriptions of bisymmetric Sugeno integrals. Computational Intelligence for Knowledge-Based Systems Design, Lecture Notes in Computer Science, Springer-Verlag, Berlin, Heidelberg: 6178, 494-501.
Couceiro, Miguel; Lehtonen, Erkko (2010) Classes of operations closed under permutation, cylindrification and composition. Proceedings of the 40th IEEE International Symposium on Multiple-Valued Logic (ISMVL 2010), IEEE Computer Society, Los Alamitos, 117-121.
Couceiro, Miguel; Lehtonen, Erkko (2008) On the arity gap of finite functions: results and applications. Proceedings of the First International Conference on Relations, Orders and Graphs: Interaction with Computer Science (ROGICS ’08), Nouha Editions, Sfax, 65-72.
Lehtonen, Erkko (2006) An infinite descending chain of Boolean subfunctions consisting of threshold functions. Contributions to General Algebra 17, Proceedings of the Vienna Conference 2005 (AAA70), Verlag Johannes Heyn, Klagenfurt, 145-148.
Couceiro, Miguel; Foldes, Stephan; Lehtonen, Erkko (2005) On the complexity of representing sets of vertices in the n-cube. ICNAAM 2005, Wiley-VCH, Weinheim, 876-877.
Couceiro, Miguel; Foldes, Stephan; Lehtonen, Erkko (2004) On compositions of clones of Boolean functions. International Conference of Computational Methods in Sciences and Engineering 2004 (ICCMSE 2004), VSP/Brill, Utrecht, 849-851.

Comunicações em Actas de Conferência

Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2012) Gap vs. pag. Proceedings of the 42nd IEEE International Symposium on Multiple-Valued Logic (ISMVL 2012), IEEE Computer Society, Los Alamitos, 268-273.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2011) On equational definability of function classes. Proceedings of the 41st IEEE International Symposium on Multiple-Valued Logic (ISMVL 2011), IEEE Computer Society, Los Alamitos, 182-186.
Couceiro, Miguel; Lehtonen, Erkko; Waldhauser, Tamás (2011) A survey on the arity gap. Proceedings of 41-st IEEE International Symposium on Multiple-Valued Logic (ISMVL 2011), IEEE Computer Society, Los Alamitos, 277-281.

Teses

Lehtonen, Erkko (2007) Operations on Finite Sets, Functional Composition, and Ordered Sets. doctoral dissertation, Tampere University of Technology, Publication 680, Tampere.

Conferências

85th Workshop on General Algebra Luxembourg, Luxembourg  (Comissão Organizadora, Comissão Científica)
4th Novi Sad Algebraic Conference (NSAC 2013) Novi Sad, Serbia  (Comunicação)
86th Workshop on General Algebra (AAA86) Olomouc, Czech Republic  (Comunicação)