Curriculum Vitæ. Giovanni Pighizzini. Dipartimento di Informatica Università degli Studi di Milano.

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1 Curriculum Vitæ Giovanni Pighizzini Dipartimento di Informatica Università degli Studi di Milano 1 Informazioni generali Laurea in Scienze dell Informazione, conseguita con lode nel 2007, presso l Università degli Studi di Milano Dottorato di ricerca in Informatica, 1993 Dal 1992 al 1998: ricercatore presso il Dipartimento di Scienze dell Informazione, Università degli Studi di Milano. Dal 1998 al 2001: professore associato di Informatica, Università degli Studi di Milano. Da ottobre 2001: professore ordinario di Informatica, Università degli Studi di Milano. Dal 2003 al 2007: presidente del Consiglio di Coordinamento Didattico di Scienze e Tecnologie Informatiche, Università degli Studi di Milano. Dal 2006: Chair dello Steering Committee del Workshop Descriptional Complexity of Formal Systems. Since 2010: Chair di IFIP Working Group 1.2 Descriptional Complexity. Dal 2010 al 2012: Direttore del Dipartimento di Informatica e Comunicazione, Università degli Studi di Milano. Membro del comitato di programma delle seguenti conferenze e workshop: STACS 2004, DCFS 2005 (co-chair), DCFS 2006 (co-chair), DCFS 2007 (co-chair), DCFS 2008 (co-chair), DCFS 2009 (co-chair), DCFS 2010 (co-chair), DCFS 2011 (co-chair), DCFS 2012, DCFS 2013, DCFS 2014, CIAA 2007, CIAA 2008, CIAA 2010, CIAA 2011, CIAA 2012, CIAA 2013, AFL 2008, AFL 2011, AFL 2014, LATA 2011, NCMA 2011, DLT 2012, DLT 2014, MFCS 2012, CSR 2014, RP 2015, STACS Chair del comitato di programma e general chair di 40th International Symposium on Mathematical Foundations of Computer Science (MFCS 2015). 1

2 Guest editor di numeri speciali delle seguenti riviste internazionali Theoretical Computer Science, Journal of Automata, Languages and Combinatorics, International Journal of Foundations of Computer Science, Electronic Proceedings in Theoretical Computer Science. Invited speaker presso varie istituzioni internazionali (LITP (Paris), LIAFA (Paris), Polish Academy of Sciences, Goethe Universität (Frankfurt), Safarik University (Ko sice, Slovakia), Slovak Academy of Sciences, University of Porto, Université Nice-Sophia Antipolis, Università degli Studi di Palermo) Invited speaker alle conferenzre AUTOMATA 2012, CIAA Best paper award alla conferenza CSR Attività didattica Cicli di lezioni di Metodi per il trattamento dell Informazione (dal 1992 al 1998). Corsi di Programmazione (dal 1996). Corsi di Linguaggi e traduttori (dal 1999). Corsi di Linguaggi formali e automi (dal 2011). Seminari per il dottorato di Algoritmi e complessità. 3 Attività scientifica Le tematiche principali dell attività scientifica riguardano: Linguaggi formali e automi. Complessità strutturale e descrizionale. Linguaggi traccia e automi asincroni. Algoritmi e complessità concreta. Ulteriori dettagli sono riportati in appendice. Giugno

3 Appendix In the last decade the scientific activity of Giovanni Pighizzini was mainly devoted to the investigation of the relationships between different kinds of formal systems from a descriptional complexity point of view. Optimal simulations between different kinds of unary automata (owe way/two way, deterministic/nondeterministic/alternating) have been obtained, by solving some long standing open problems [13, 15, 18, 60]. Furthermore, he obtained a subexponential (in terms of states) simulation of two way nondeterministic unary automata by two way deterministic automata [20, 26] and, he proved an important connection with the question in space complexity of the relationship between deterministic and nondeterministic computations bounded in logarithmic space [38, 42]. Stronger connections have been recently discovered [49, 65]. These results are relevant contributions to the study of the long standing open question posed by Sakoda and Sipser concerning the simulation of two way nondeterministic automata by two way deterministic automata. Further results concerning the state complexity of finite state automata, in particular considering operations on languages, are presented in [22, 27, 29, 38]. Recently, the previous results concerning unary two-way nondeterministic automata have been extended to a model accepting also nonunary languages with a restricted nondeterministic capabilities [47]. In [48] another restricted model of two-way nondeterministic automata have been considered. In [33, 41], he investigated the state complexity of self-verifying automata, a model of finite state machines with a restricted form of nondeterminism. These investigations have been further extended by considering other computational and formal models, as probabilistic automata, pebble automata, pushdown automata and context free grammars [17, 24, 36, 39, 40, 43, 44]. In particular, he obtained a tight conversion of context free grammars and pushdown automata accepting unary languages into finite automata. This result was also useful to solve an open problem concerning auxiliary pushdown automata [16, 23] In [30], the study of the relationship between the descriptional complexity of context-free grammars and pushdown automata was extended from the unary case to the case of bounded languages, proving an optimal trade-off (note that in the case of general context-free languages there are nonrecursive trade-offs). Descriptional complexity aspects of regular and context-free languages under Parikh equivalence have been investigated in [45, 51, 56, 61]. In [31], a pumping condition for ultralinear languages has been proved. In [55, 57, 59, 64], Turing machines with restricted rewriting capabilities have been considered, proving relationships with other models, in terms of computational and descriptional power. In [35], tight time lower bounds for the recognition of nonregular languages by several variant of nondeterministic machines have been obtained. In [19, 25, 28], problems concerning the computation of the distance between strings and between strings and languages have been considered, by presenting efficient algorithms computing such distances. 3

4 A Recent papers [1] E. Allender, D. Bruschi, G. Pighizzini. The complexity of computing maximal word functions. Computational Complexity, 3: , Birkhäuser Verlag, Basel, [2] G. Pighizzini. Synthesis of nondeterministic asynchronous automata. In M. Droste, Y. Gurevich (ed.), Semantics of Programming Languages and Model Theory, in Algebra, Logic and Applications 5, pp Gordon and Breach Science Publ., Amsterdam, [3] A. Bertoni, G. Mauri, G. Pighizzini, N. Sabadini. Algebraic and informational aspects of Zielonka s theorem. In C. Bonzini, A. Cherubini, C. Tibiletti (ed.), Semigroups, pp World Scientific, Singapore, [4] D. Bruschi, G. Pighizzini, N. Sabadini. On the existence of minimum asynchronous automata and on the equivalence problem for unambiguous regular trace languages. Information and Computation, 108: , Academic Press, New York London, [5] A. Bertoni, C. Mereghetti, G. Pighizzini. On languages accepted with simultaneous complexity bounds and their ranking problem. In J. Prívara, B. Rovan, P. Ru zi cka (ed.), Mathematical Foundations of Computer Science 1994, Proceedings, Lecture Notes in Computer Science 841, pp Springer Verlag, Berlino, [6] G. Pighizzini. Asynchronous automata versus asynchronous cellular automata. Theoretical Computer Science, 132: , Elsevier, Amsterdam, [7] A. Bertoni, C. Mereghetti, G. Pighizzini. An optimal lower bound for nonregular languages. Information Processing Letters, 50: , Elsevier, Amsterdam, [8] C. Mereghetti, G. Pighizzini. A remark on middle space bounded alternating Turing machines. Information Processing Letters, 56: , Elsevier, Amsterdam, [9] G. Pighizzini. How hard is to compute the edit distance. In H. Reichel (ed.), Fundamentals of Computation Theory 1995, Proceedings, Lecture Notes in Computer Science 965, pp Springer, [10] A. Bertoni, C. Mereghetti, G. Pighizzini. Strong optimal lower bounds for Turing machines that accept nonregular languages. In J. Wiedermann, P. Hájek (ed.), Mathematical Foundations of Computer Science 1995, Proceedings, Lecture Notes in Computer Science 969, pp Springer, [11] S. Jesi, G. Pighizzini, N. Sabadini. Probabilistic asynchronous automata. Mathematical Systems Theory, 29:5 31, Springer Verlag, New York, [12] C. Choffrut, G. Pighizzini. Distances between languages and reflexivity of relations. In J. Prívara, P. Ru zi cka (ed.), Mathematical Foundations of Computer Science 1997, Proceedings, Lecture Notes in Computer Science 1295, pp ,

5 [13] C. Mereghetti, G. Pighizzini. Optimal simulations between unary automata. STACS 98, Proceedings, Lecture Notes in Computer Science 1373, pp , [14] V. Geffert, C. Mereghetti, G. Pighizzini. Sublogarithmic bounds on space and reversals. SIAM Journal on Computing 28: , [15] C. Mereghetti, G. Pighizzini. Two-Way Automata Simulations and Unary Languages. Journal of Automata, Languages and Combinatorics 5: , [16] G. Pighizzini. Unary Pushdown Automata and Auxiliary Space Lower Bounds. Mathematical Foundations of Computer Science 2000, Proceedings, Lecture Notes in Computer Science 1893, pages , [17] M. Milani, G. Pighizzini. Tight bounds on the simulation of unary probabilistic automata by deterministic automata. Journal of Automata, Languages and Combinatorics 6: , [18] C. Mereghetti, G. Pighizzini. Optimal Simulations Between Unary Automata. SIAM Journal on Computing 30: , 2001 [19] G. Pighizzini. How Hard Is Computing the Edit Distance? Information and Computation 165:1-13, [20] V. Geffert, C. Mereghetti, G. Pighizzini. Converting Two-Way Nondeterministic Unary Automata into Simpler Automata. Mathematical Foundations of Computer Science 2001, Proceedings, Lecture Notes in Computer Science, [21] C. Mereghetti, B. Palano, G. Pighizzini. On the Succinctness of Deterministic, Nondeterministic, Probabilistic and Quantum Finite Automata. RAIRO Theoretical Informatics and Applications 5: , [22] G. Pighizzini, J.Shallit. Unary Language Operations, State Complexity and Jacobsthal s Function. International Journal of Foundations of Computer Science 13: , [23] G. Pighizzini, J. Shallit, M.-w. Wang. Unary context free grammars and pushdown automata, descriptional complexity and auxiliary space lower bounds. Journal of Computer and System Sciences 65: , [24] M. Domaratzki, G. Pighizzini, J. Shallit. Simulating finite automata with context-free grammars. Information Processing Letters 84: , [25] C. Choffrut, G. Pighizzini. Distances between languages and reflexivity of relations. Theoretical Computer Science 286: , [26] V. Geffert, C. Mereghetti, G. Pighizzini. Converting Two-Way Nondeterministic Unary Automata into Simpler Automata. Theoretical Computer Science 295: ,

6 [27] F. Mera, G. Pighizzini. Complementing Unary Nondeterministic Automata. Theoretical Computer Science, 330: , [28] D. Bruschi and G. Pighizzini. String Distances and Intrusion Detection: Bridging the gap between formal languages abd computer security. RAIRO Theoretical Informatics and Applications 40, , [29] V. Geffert, C. Mereghetti, G. Pighizzini. Complementing Two-Way Finite Automata. Information and Computation 205: , [30] A. Malcher, G. Pighizzini. Descriptional Complexity of Bounded Context-Free Languages. Developments of Language Theory 2007, Proceedings, Lecture Notes in Computer Science 4588, pp , [31] E. Magalini, G. Pighizzini. A Pumping Condition for Ultralinear Languages. International Journal of Foundations of Computer Science, 18: , [32] G. Pighizzini. Deterministic Pushdown Automata and Unary Languages. Proceedings of the 13th Conference on Implementation and Application of Automata, CIAA 2008, Lecture Notes in Computer Science 5148, pp , [33] G. Jirásková, G. Pighizzini. Converting Self-Verifying Automata into Deterministic Automata. Proceedings of LATA 2009, Lecture Notes in Computer Science 5457, pp , [34] G. Pighizzini. Deterministic Pushdown Automata and Unary Languages. International Journal of Foundations of Computer Science 20: , [35] G. Pighizzini. Nondeterministic one-tape off-line Turing machines and their time complexity. Journal of Automata, Languages and Combinatorics 14: , [36] V. Geffert, C. Mereghetti, G. Pighizzini. One pebble versus log n bits. Proceedings of the Workshop Non-Classical Models for Automata and Applications (NCMA), , [37] V. Geffert, G. Pighizzini. Pairs of Complementary Unary Languages with Balanced Nondeterministic Automata. Proceedings of LATIN 2010, Lecture Notes in Computer Science 6034, pp , [38] V. Geffert, G. Pighizzini. Two-Way Unary Automata versus Logarithmic Space. Developments of Language Theory 2010, Proceedings, Lecture Notes in Computer Science 6224, pp , [39] V. Geffert, C. Mereghetti, G. Pighizzini. One Pebble Versus ɛ log n Bits. Fundamenta Informaticae 104:55-69, [40] M.P. Bianchi, C. Mereghetti, B. Palano, G. Pighizzini. Probabilistic vs. Nondeterministic Unary Automata. Proceedings of the 2nd Workshop Non-Classical Models for Automata and Applications (NCMA 2010), 33-44,

7 [41] G. Jirásková, G. Pighizzini. Optimal simulation of self-verifying automata by deterministic automata. Information and Computation 209, , [42] V. Geffert, G. Pighizzini. Two-Way Unary Automata versus Logarithmic Space. Information and Computation 209, , [43] M.P. Bianchi, G. Pighizzini. Normal Forms for Unary Probabilistic Automata. Proceedings of the 3nd Workshop Non-Classical Models for Automata and Applications (NCMA 2011), , [44] M.P. Bianchi, C. Mereghetti, B. Palano, G. Pighizzini. On the Size of Unary Probabilistic and Nondeterministic Automata. Fundamenta Informaticae 112(2-3), , [45] G. Lavado, G. Pighizzini. Parikh s Theorem and Descriptional Complexity. SOFSEM 2012: Theory and Practice of Computer Science, Lecture Notes in Computer Science 7147, pp , [46] V. Geffert, G. Pighizzini. Pairs of Complementary Unary Languages with Balanced Nondeterministic Automata. Algorithmica 63(3), , [47] V. Geffert, B. Guillon, G. Pighizzini. Two-Way Automata Making Choices Only at the Endmarkers. Proceedings of LATA 2012, Lecture Notes in Computer Science 7183, pp , [48] M. Kutrib, A. Malcher, G. Pighizzini. Oblivious Two-Way Finite Automata: Decidability and Complexity. Proceedings of LATIN 2012, Lecture Notes in Computer Science 7256, pages , [49] Ch. Kapoutsis, G. Pighizzini. Two-way Automata Characterizations of L/poly versus NL. Proceedings of CSR 2012, Lecture Notes in Computer Science 7353, pages , [50] M.P. Bianchi, M. Holzer, S. Jakobi, and G. Pighizzini. On Inverse Operations and Their Descriptional Complexity. Proceedings of DCFS 2012, Lecture Notes in Computer Science, 7386, pages , [51] G.J. Lavado, G. Pighizzini, and S. Seki. Converting Nondeterministic Automata and Context- Free Grammars into Parikh Equivalent Deterministic Automata. Proceedings of DLT 2012, Lecture Notes in Computer Science 7410, pages , [52] C.A. Kapoutsis and Giovanni Pighizzini. Reversal Hierarchies for Small 2DFAs. Proceedings of MFCS 2012, Lecture Notes in Computer Science 7464, pages , [53] M.P. Bianchi and G. Pighizzini. Normal forms for unary probabilistic automata. RAIRO Theoretical Informatics and Applications, [54] A. Malcher and G. Pighizzini. Descriptional Complexity of Bounded Context-Free Languages. Information and Computation, 227, 1-20,

8 [55] G. Pighizzini and A. Pisoni. Limited Automata and Regular Languages. Proceedings of DCFS 2013, Lecture Notes in Computer Science 8031, pages , [56] G.J. Lavado, G. Pighizzini, and S. Seki. Converting nondeterministic automata and contextfree grammars into Parikh equivalent one-way and two-way deterministic automata. Information and Computation, , 1-15, [57] G. Pighizzini and A. Pisoni. Limited Automata and Context-Free Languages. Proceedings of the 5th Workshop Non-Classical Models for Automata and Applications (NCMA 2013), , [58] G. Pighizzini. Two-Way Finite Automata: Old and Recent Results. Fundamenta Informaticae, 126(2-3), , [59] G. Pighizzini. Strongly Limited Automata. Proceedings of the 6th Workshop Non-Classical Models for Automata and Applications (NCMA 2014), , [60] G. Pighizzini. Investigations on Automata and Languages over a Unary Alphabet. Proceedings of CIAA 2014, Lecture Notes in Computer Science 8587, pages 42-57, [61] G.J. Lavado, G. Pighizzini, and S. Seki. Operational State Complexity under Parikh Equivalence. Proceedings of DCFS 2014, Lecture Notes in Computer Science 8614, pages , [62] M. Kutrib, A. Malcher, and G. Pighizzini. Oblivious two-way finite automata: Decidability and complexity. Information and Computation, 237, , [63] V. Geffert, B. Guillon, G. Pighizzini. Two-Way Automata Making Choices Only at the Endmarkers. Information and Computation, 239, 71-86, [64] G. Pighizzini and A. Pisoni. Limited Automata and Regular Languages. International Journal of Foundations of Computer Science 25: , [65] Ch. Kapoutsis, G. Pighizzini. Two-way Automata Characterizations of L/poly versus NL. Theory of Computing Systems, 56, [66] N. Moreira, G. Pighizzini, and R. Reis. Optimal State Reductions of Automata with Partially Specified Behaviors. Proceedings of SOFSEM 2015, Lecture Notes in Computer Science 8939, pages , [67] G. Pighizzini and A. Pisoni. Limited Automata and Context-Free Languages. Fundamenta Informaticae 136: ,

9 B Recent Books [b1] M. Holzer, M. Kutrib, G. Pighizzini (eds.). Descriptional Complexity of Formal Systems - 13th International Workshop, DCFS Proceedings. Lecture Notes in Computer Science 6808, Springer 2011, ISBN [b2] G. Pighizzini, M. Ferrari. Dai fondamenti agli oggetti. Corso di programmazione Java. Quarta Edizione. Pearson 2015, ISBN (1st ed. 2002, 2nd ed. 2005, 3rd ed. 2008) [b3] G. Italiano, G. Pighizzini, D. Sannella (eds.) Mathematical Foundations of Computer Science th International Symposium, MFCS Proceedings, part I. Lecture Notes in Computer Science 9234, Springer 2015 (to appear). [b4] G. Italiano, G. Pighizzini, D. Sannella (eds.) Mathematical Foundations of Computer Science th International Symposium, MFCS Proceedings, part II. Lecture Notes in Computer Science 9235, Springer 2015 (to appear). 9