Research/art/teacher profile of a person
- The name of the university:
- Pavol Jozef Šafárik University in Košice
- The seat of the university:
- Šrobárova 2, 041 80 Košice
- The name of the faculty:
- Faculty of Science
- The seat of the faculty:
- Šrobárova 2, 040 01 Košice
I. - Basic information
I.1 - Surname
Geffert
I.2 - Name
Viliam
I.3 - Degrees
prof., RNDr., DrSc
I.4 - Year of birth
1955
I.5 - Name of the workplace
University of P.J. Šafárik in Košice, Faculty of Science, Institute of Informatics
I.6 - Address of the workplace
Jesenná 5, 041 54 Košice, Slovakia
I.7 - Position
professor
I.8 - E-mail address
viliam.geffert@upjs.sk
I.9 - Hyperlink to the entry of a person in the Register of university staff
https://www.portalvs.sk/regzam/detail/15260
I.10 - Name of the study field in which a person works at the university
Informatics
I.11 - ORCID iD
0000-0001-9143-1476
II. - Higher education and further qualification growth
II.1 - First degree of higher education
II.2 - Second degree of higher education
II.a - Name of the university or institution
University of P.J. Šafárik in Košice, Faculty of Science
II.b - Year
1979
II.c - Study field and programme
Theoretical cybernetics
II.3 - Third degree of higher education
II.a - Name of the university or institution
Comenius University, Faculty of Mathematics, Physics, and Computer Science, Bratislava, Slovakia
II.b - Year
1988
II.c - Study field and programme
Theoretical Informatics
II.4 - Associate professor
II.a - Name of the university or institution
Comenius University, Faculty of Mathematics, Physics, and Computer Science, Bratislava, Slovakia
II.b - Year
1993
II.c - Study field and programme
Matematical Informatics and Theoretical Cybernetics
II.5 - Professor
II.a - Name of the university or institution
University of P.J.Šafárika, Faculty of Science, Košice, Slovakia
II.b - Year
2003
II.c - Study field and programme
Informatics
II.6 - Doctor of Science (DrSc.)
II.a - Name of the university or institution
Mathematical Institute of Slovak Academy of Science, Bratislava, Slovakia
II.b - Year
2001
II.c - Study field and programme
Theoretical Informatics
III. - Current and previous employment
| III.a - Occupation-position | III.b - Institution | III.c - Duration |
|---|---|---|
| professor | University of P.J. Šafárik in Košice, Faculty of Science | 1979 - till now |
IV. - Development of pedagogical, professional, language, digital and other skills
V. - Overview of activities within the teaching career at the university
V.1 - Overview of the profile courses taught in the current academic year according to study programmes
| V.1.a - Name of the profile course | V.1.b - Study programme | V.1.c - Degree | V.1.d - Field of study |
|---|---|---|---|
| AFJ1a Automata and formal languages | Ib – Informatics | bachelor 1st deg. | 18. – Informatics |
| AFJ1b Automata and formal languages II | Ib – Informatics | bachelor 1st deg. | 18. – informatics |
| VYZ1 Computational complexity | Im – Informatics | master 2nd deg. | 18. - informatics |
| AFJ1a Automata and formal languages | BIb - Biology - Informatics | bachelor 1st deg.. | Interdisciplinary study |
| VYMD Computational complexity and Models of Computation | Id – informatics | Phd. study 3rd deg. | 18. – informatics |
V.2 - Overview of the responsibility for the delivery, development and quality assurance of the study programme or its part at the university in the current academic year
| V.2.a - Name of the study programme | V.2.b - Degree | V.2.c - Field of study |
|---|---|---|
| Ib – Informatics | bachelor 1st deg. | 18. – informatics |
| Im – Informatics | master 2nd deg. | 18. - informatics |
| BIb - Biológy - Informatics | bachelor 1st deg. | Interdisciplinary study |
| BImu - Biology - Informatics | master 2nd deg. | teachers' study |
| ADUIm - Data Analysis and Artificial Intelligence | aster 2nd deg. | Interdisciplinary study |
V.3 - Overview of the responsibility for the development and quality of the field of habilitation procedure and inaugural procedure in the current academic year
| V.3.a - Name of the field of habilitation procedure and inaugural procedure | V.3.b - Study field to which it is assigned |
|---|---|
| Informatics | Informatics |
V.4 - Overview of supervised final theses
V.4.1 - Number of currently supervised theses
V.4.a - Bachelor's (first degree)
V.4.b - Diploma (second degree)
V.4.c - Dissertation (third degree)
1
V.4.2 - Number of defended theses
V.4.a - Bachelor's (first degree)
3
V.4.b - Diploma (second degree)
21
V.4.c - Dissertation (third degree)
5
V.5 - Overview of other courses taught in the current academic year according to study programmes
| V.5.a - Name of the course | V.5.b - Study programme | V.5.c - Degree | V.5.d - Field of study |
|---|---|---|---|
| AFJ1a Automata and formal languages | AIb - Applied Informatics | bachelor 1st deg. | 18. - informatics |
| FO1 Formal languages and Automata | BImu - Biology - Informatics | master 2nd deg. | teachers' study |
| VYZ1 Computational complexity | ADUIm - Data Analysis and Artificial Intelligence | master 2nd deg. | Interdisciplinary study |
| VYZ1 Computational complexity | BImu - Biolygy – Informatics | master 2nd deg. | teachers' study |
VI. - Overview of the research/artistic/other outputs
VI.1 - Overview of the research/artistic/other outputs and the corresponding citations
VI.1.1 - Number of the research/artistic/other outputs
VI.1.a - Overall
96
VI.1.b - Over the last six years
10
VI.1.2 - Number of the research/artistic/other outputs registered in the Web of Science or Scopus databases
VI.1.a - Overall
51
VI.1.b - Over the last six years
10
VI.1.3 - Number of citations corresponding to the research/artistic/other outputs
VI.1.a - Overall
374
VI.1.b - Over the last six years
79
VI.1.4 - Number of citations registered in the Web of Science or Scopus databases
VI.1.a - Overall
374
VI.1.b - Over the last six years
79
VI.1.5 - Number of invited lectures at the international, national level
VI.1.a - Overall
9
VI.1.b - Over the last six years
0
VI.2 - The most significant research/artistic/other outputs
ADC – V.Geffert: Normal forms for phrase-structure grammars, RAIRO - Informatique Theorique et Applications, 1991, Vol.25, No.5, pp.473-496
ADC – V.Geffert: Nondeterministic computations in sublogarithmic space and space constructibility, SIAM J. of Computing, 1991, Vol.20, No.3, pp.484-498
ADC – V.Geffert: Tally versions of the Savitch and Immerman-Szelepcsenyi theorems for sublogarithmic space, SIAM J. of Computing, 1993, Vol.22, No.1, pp.102-113
ADC – V.Geffert, J.Katajainen, T.Pasanen: Asymptotically efficient in-place merging, Theoretical Computer Science, Elsevier, 2000, Vol.237, pp.159-181
ADC – G.Franceschini, V.Geffert: An in-place sorting with O(n.log n) comparisons and O(n) moves, J. of the ACM, ACM Press, 2005, Vol.52, No.4, pp.515-537
VI.3 - The most significant research/artistic/other outputs over the last six years
ADC – Z.Bednárová, V.Geffert, K.Reinhardt, A.Yakaryilmaz: New results on the minimum amount of useful space, International Journal of Foundations of Computer Science, World Scientific, 2016, Vol.27, No.2, pp.259-281
ADC – V.Geffert, Z.Bednárová, C.Mereghetti, B.Palano: Boolean language operations on nondeterministic automata with a pushdown of constant height, Journal of Computer and System Sciences, Elsevier, 2017, Vol.90, pp.99-114
ADC – Z.Bednárová, V.Geffert: Two double-exponential gaps for automata with a limited pushdown, Information and Computation, Elsevier, 2017, Vol.253, pt.3, pp.381-398
AFC – V.Geffert, Z.Bednárová, A.Szabari: Input-driven pushdown automata for edit distance neighborhood, Proc. of DLT 2019 (Developments in Language Theory), Lecture Notes in Computer Science 11647, Springer-Verlag, 2019, pp. 113-126
ADC – V.Geffert: Unary coded PSPACE-complete languages in ASPACE(loglog n), Theory of Computing Systems, Springer-Verlag, 2019, Vol.63, No.4, pp.688-714
VI.4 - The most significant citations corresponding to the research/artistic/other outputs
ADC – V.Geffert: Normal forms for phrase-structure grammars, RAIRO - Informatique Theorique et Applications, 1991, Vol.25, No.5, pp.473-496: 19 ohlasov WoK 1. J.Gruska: Foundations of Computing, Internat. Thomson Computer Press (ITP), USA, 1997 2. A.Matescu, A.Salomaa: Aspects of classical language theory. In G.Rozenberg, A.Salomaa (eds.), Handbook of formal languages, Vol.I: Word, language, grammar. Springer-Verlag, 1997 3. M.Jantzen, H.Petersen: Cancellation in context-free languages: Enrichment by reduction, Theoretical Computer Science, Elsevier, 1994, Vol.127, No.1, pp.149-170 4. J.Dassow, V.Mitrana, and A.Salomaa: Context-free evolutionary grammars and the structural language of nucleic-acids, Biosystems, Elsevier, 1997, Vol.43, No.3, pp.169-177 5. G.Paun: DNA computing based on splicing: Universality results, Theoretical Computer Science, Elsevier, 2000, Vol.231, No.2, pp.275-296 6. E.Csuhaj-Varju, V.Mitrana: Evolutionary systems: A language generating device inspired by evolving communities of cells, Acta Informatica, Springer-Verlag, 2000, Vol.36, No.11, pp.913-926 7. E.Csuhaj-Varjú, C.Martín-Vide, V.Mitrana: Hybrid networks of evolutionary processors are computationally complete, Acta Informatica, Springer-Verlag, 2005, Vol.41, No.4-5, pp.257-272 8. F.Okubo: A note on the descriptional complexity of semi-conditional grammars, Information Processing Letters, 2009, Vol.110, No.1, pp.36-40 9. R.Freund, M.Oswald: CD grammar systems with regular start conditions, Internat. J. of Foundations of Computer Science, 2008, Vol.19, No.4, pp.767-779 10. K.Fujioka, H.Katsuno: On the generative power of cancel minimal linear grammars with single nonterminal symbol except the start symbol, IEICE Transactions on Information and Systems, 2011, Vol.E94D, No.10, pp.1945-1954
ADC – V.Geffert: Nondeterministic computations in sublogarithmic space and space constructibility, SIAM J. of Computing, 1991, Vol.20, No.3, pp.484-498: 32 ohlasov WoK 1. A.Szepietowski: Turing machines with sublogarithmic space, Lecture Notes in Computer Science 843, Springer-Verlag, 1994, 115pp. 2. M.Liskiewicz, R.Reischuk: Computing with sublogarithmic space. In L.A.Hemaspaandra, A.L.Selman (eds.), Complexity theory retrospective II, Springer-Verlag, 1997 3. K.Inoue, A.Ito, I.Takanami: A relationship between nondeterministic Turing machines and 1-inkdot Turing machines with small space, Information Processing Letters, North-Holland, 1992, Vol.43, No.4, pp.225-227 4. K.Inoue, A.Ito, I.Takanami: A note on 1-inkdot alternating Turing machines with small space, Theoretical Computer Science, Elsevier, 1994, Vol.127, No.1, pp.171-179 5. M.Liskiewicz, R.Reischuk: The sublogarithmic alternating space world, SIAM J. of Computing, 1996, Vol.25, No.4, pp.828-861 6. A.Ito, K.Inoue, I.Takanami, Y.Wang: The Effect of Inkdots for 2-Dimensional Automata, International J. of Pattern Recognition and Artificial Intelligence, World Scientific, 1995, Vol.9, No.5, pp.777-796 7. K.Inoue, A.Ito, I.Takanami, T.Yoshinaga: A Note on Multi-Inkdot Nondeterministic Turing-Machines with Small Space, Information Processing Letters, Elsevier, 1993, Vol.48, No.6, pp.285-288 8. C.Mereghetti and G.Pighizzini: Optimal simulations between unary automata, SIAM J. of Computing, 2001, Vol.30, No.6, pp.1976-1992 9. J.L.Xu, Y.X.Liu, T.Yoshinaga: A note on non-closure property of sublogarithmic space-bounded 1-inkdot alternating pushdown automata with only existential (universal) states, J. Comput. Sci. Technol. (J. of Computer Science and Technology), 2006, Vol.21, No.6, pp.979-983 10. T.Makino, H.Okabe, S.Taniguchi, M.Sakamoto, K.Inoue: Three-dimensional multiinkdot automata, Artificial Life and Robotics, 2005, Vol.9, No.2, pp.99-101
ADC – V.Geffert: Tally versions of the Savitch and Immerman-Szelepcsenyi theorems for sublogarithmic space, SIAM J. of Computing, 1993, Vol.22, No.1, pp.102-113: 19 ohlasov WoK 1. M.Liskiewicz, R.Reischuk: Computing with sublogarithmic space. In L.A.Hemaspaandra, A.L.Selman (eds.), Complexity theory retrospective II, Springer-Verlag, 1997 2. A.Matescu, A.Salomaa: Aspects of classical language theory. In G.Rozenberg, A.Salomaa (eds.), Handbook of formal languages, Vol.I: Word, language, grammar. Springer-Verlag, 1997 3. C.Damm, M.Holzer: Inductive counting for width-restricted branching programs, Information and Computation, Academic Press, 1996, Vol.130, No.1, pp.91-99 4. M.Liskiewicz, R.Reischuk: The sublogarithmic alternating space world, SIAM J. of Computing, 1996, Vol.25, No.4, pp.828-861 5. C.Mereghetti and G.Pighizzini: A remark on middle space bounded alternating Turing machines, Information Processing Letters, Elsevier, 1995, Vol.56, No.4, pp.229-232 6. A.Szepietowski: Weak and strong one-way space complexity classes, Information Processing Letters, Elsevier, 1998, Vol.68, No.6, pp.299-302 7. C.Mereghetti and G.Pighizzini: Optimal simulations between unary automata, SIAM J. of Computing, 2001, Vol.30, No.6, pp.1976-1992 8. G.Pighizzini, J.Shallit, M.-W.Wang: Unary context-free grammars and pushdown automata, descriptional complexity and auxiliary space lower bounds, J. Computer and System Sciences, 2003, Vol.65, No.2, pp.393-414 9. G.Pighizzini: Unary language concatenation and its space complexity, Proc.of CIAA 2000 (Confer. on Implementation and Application of Automata), Lecture Notes in Computer Science, Springer-Verlag, 2001, Vol.2088, pp.252-262 10. C.Mereghetti: Testing the descriptional power of small Turing machines on nonregular language acceptance, Internat. J. of Foundations of Computer Science, 2008, Vol.19, No.4, pp.827-843
ADC – V.Geffert, J.Katajainen, T.Pasanen: Asymptotically efficient in-place merging, Theoretical Computer Science, Elsevier, 2000, Vol.237, pp.159-181: 25 ohlasov WoK 1. J.Ellis, M.Markov: In situ, stable merging by way of the perfect shuffle, Computer J., Oxford Univ. Press, 2000, Vol.43, No.1, pp.40-53 2. Jingchao Chen: Optimizing a stable in-place merging, Theoretical Computer Science, Elsevier, 2003, Vol.302, pp.191-210 3. J.-C.Chen: A simple algorithm for in-place merging, Information Processing Letters, 2006, Vol.98, No.1, pp.34-40 4. L.A.Hemaspaandra, P.Mukherji, T.Tantau: Context-free languages can be accepted with absolutely no space overhead, Information and Computation, 2005, Vol.203, No.2, pp.163-180 5. J.Vahrenhold: Line-segment intersection made in-place, Computational Geometry-Theory and Applications, Elsevier, 2007, Vol.38, No.3, pp.213-230 6. P.Bose, A.Maheshwari, P.Morin, J.Morrison, M.Smid, J.Vahrenhold: Space-efficient geometric divide-and-conquer algorithms, Computational Geometry-Theory and Applications, Elsevier, 2007, Vol.37, No.3, pp.209-227 7. J.Vahrenhold: An in-place algorithm for Klee's measure problem in two dimensions, Information Processing Letters, 2007, Vol.102, No.4, pp.169-174 8. P.S.Kim, A.Kutzner: Stable minimum storage merging by symmetric comparisons, Proc.of ESA 2004 (Eur. Symp. Algorithms), Lecture Notes in Computer Science, Springer-Verlag, 2004, Vol.3221, pp.714-723 9. H.Blunck, J.Vahrenhold: In-place algorithms for computing (Layers of) maxima, Algorithmica (New York), 2010, Vol.57, No.1, pp.1-21 10. M.E.Dalkilic, E.Acar, G.Tokatli: A simple shuffle-based stable in-place merge algorithm, Proc. of WCIT-2010 (World Conference on Inrofmation Technology 2010), Procedia Computer Science, 2011, Vol.3, pp.1049-1054
ADC – V.Geffert, A.Badr, I.Shipman: Hyper-minimizing minimized deterministic finite state automata, RAIRO - Theoretical Informatics and Applications, EDP Sciences, 2009, Vol.43, pp.69-94 (DOI: 10.1051/ita:2007061) : 13 ohlasov WoK 1. M.Holzer, A.Maletti: An O(n log n) algorithm for hyper-minimizing states in a (minimized) deterministic automaton, Proc. of CIAA 2009 (Confer. on Implementation and Application of Automata), Lecture Notes in Computer Science 5642, Springer-Verlag, 2009, pp.4-13 2. M.Holzer, A.Maletti: An n.log n algorithm for hyper-minimizing a (minimized) deterministic automaton, Theoretical Computer Science, Elsevier, 2010, Vol.411, No.38-39, pp.3404-3413 3. M.Holzer, S.Jacobi: From equivelence to almost-equivalence and beyond -- minimizing automata with errors, Proc. of DLT 2012 (Developments in Language Theory), Lecture Notes in Computer Science 7410, Springer-Verlag, 2012, pp.190-201 4. A.Jez, A.Maletti: Hyper-minimization for deterministic tree automata, Proc. of CIAA 2012 (Conference on Implementation and Application of Automata), Lecture Notes in Computer Science, 7381, Springer-Verlag, 2012, pp.217-228 5. H.Björklund, W.Martens: The tractability frontier for NFA minimization, J. Computer and System Sciences, 2012, Vol.78, No.1, pp.198-210 6. A.Szepietowski: Closure properties of hyper-minimized automata, RAIRO - Theoretical Informatics and Applications, 2011, Vol.45, No.4, pp.459-466 7. A.Maletti, D.Quernheim: Optimal hyper-minimization, Internat. J. Foundations of Computer Science, 2011, Vol.22, No.8, pp.1877-1891 8. P.Gawrychowski, A.Jez, A.Maletti: On minimising automata with errors, Proc. of MFCS 2011 (Mathematical Foundations of Computer Science), Lecture Notes in Computer Science, 6907, Springer-Verlag, 2011, pp.327-338 9. A.Jez, A.Maletti: Computing all ℓ-cover automata fast, Proc. of CIAA 2011 (Conference on Implementation and Application of Automata), Lecture Notes in Computer Science, 6807, Springer-Verlag, 2011, pp.203-214 10. A.Maletti: Better hyper-minimization not as fast, but fewer errors, Proc. of CIAA 2010 (Conference on Implementation and Application of Automata), Lecture Notes in Computer Science, 6482, Springer-Verlag, 2011, pp.201-210
VI.5 - Participation in conducting (leading) the most important research projects or art projects over the last six years
VEGA 1/0479/12 „Combinatorial structures and complexity of algorithms“, 2012-2014, principal investigator
VEGA 1/0177/21 "Decsriptional and Computational Complexity of Automata and Algorithms", 2021-2023, pricipal investigator.
Project summary: Efficient representation of languages by transducers and automata, as well as state complexity analysis for alternating automata and combined language operations. Design of time-efficient algorithms in the area of matching and resource allocation problems, and for k-path vertex cover for special types of graphs and their applications.
VEGA 1/0142/15 „Combinatorial structures and complexity of algorithms“, 2015-2017, principal investigator
VEGA 1/0056/18 „Descriptional and computational complexity of automata and algorithms“, 2018-2020, principal investigator
APVV-15-0091 „Efficient algoritms, automata, and data structures“, 2016-2020, principal investigator
VII. - Overview of organizational experience related to higher education and research/artistic/other activities
VIII. - Overview of international mobilities and visits oriented on education and research/artistic/other activities in the given field of study
IX. - Other relevant facts
IX.a - If relevant, other activities related to higher education or research/artistic/other activities are mentioned
IFIP (International Federation for Information Processing) -- Working Group 1.2 on Descriptional Complexity - member,
Slovak Society for Computer Science - member,
Editorial Board of Tatra Mountains Mathematical Publications - member
Date of last update
2023-09-08