Cristian S. Calude

Cristian S. Calude, Elena Calude: Algorithmic Complexity of Mathematical Problems: An Overview of Results and Open Problems. IJUC 9(3-4): 327-343 (2013)

Cristian S. Calude, Elena Calude, Melissa S. Queen: Inductive Complexity of the P versus NP Problem. Parallel Processing Letters 23(1) (2013)

Cristian S. Calude, J. P. Lewis: Is there a universal image generator? Applied Mathematics and Computation 218(16): 8151-8159 (2012)

Cristian S. Calude, José Félix Costa, Hélia Guerra: Preface to the Special Issue on Physics and Computation "Towards a Computational Interpretation of Physical Theories". Applied Mathematics and Computation 219(1): 1-2 (2012)

Alastair A. Abbott, Cristian S. Calude: Von Neumann Normalisation of a Quantum Random Number Generator. Computability 1(1): 59-83 (2012)

David H. Bailey, Jonathan M. Borwein, Cristian S. Calude, Michael J. Dinneen, Monica Dumitrescu, Alex Yee: An Empirical Approach to the Normality of π. Experimental Mathematics 21(4): 375-384 (2012)

Cristian S. Calude, Kai Salomaa, Tania Roblot: State-Size Hierarchy for Finite-State Complexity. Int. J. Found. Comput. Sci. 23(1): 37-50 (2012)

Alastair A. Abbott, Matthias Bechmann, Cristian S. Calude, Angelika Sebald: A Nuclear Magnetic Resonance Implementation of a Classical Deutsch-Jozsa Algorithm. IJUC 8(2): 161-175 (2012)

Cristian S. Calude, S. Barry Cooper: Introduction: computability of the physical. Mathematical Structures in Computer Science 22(5): 723-728 (2012)

Cristian S. Calude, Elena Calude, Melissa S. Queen: The complexity of Euler's integer partition theorem. Theor. Comput. Sci. 454: 72-80 (2012)

Cristian S. Calude, Elena Calude, Melissa S. Queen: Inductive Complexity of P versus NP Problem - Extended Abstract. UCNC 2012: 2-9

Ali Akhtarzada, Cristian S. Calude, John G. Hosking: A Multi-Criteria Metric Algorithm for Recommender Systems. Fundam. Inform. 110(1-4): 1-11 (2011)

Cristian S. Calude, Matteo Cavaliere, Radu Mardare: An Observer-Based de-Quantisation of Deutsch's Algorithm. Int. J. Found. Comput. Sci. 22(1): 191-201 (2011)

Cristian S. Calude, José Félix Costa: Editorial. IJUC 7(5): 313 (2011)

Cristian S. Calude, Nicholas J. Hay, Frank Stephan: Representation of left-computable ε-random reals. J. Comput. Syst. Sci. 77(4): 812-819 (2011)

Cristian S. Calude: Simplicity via provability for universal prefix-free Turing machines. Theor. Comput. Sci. 412(1-2): 178-182 (2011)

Cristian S. Calude, André Nies, Ludwig Staiger, Frank Stephan: Universal recursively enumerable sets of strings. Theor. Comput. Sci. 412(22): 2253-2261 (2011)

Cristian S. Calude, Kai Salomaa, Tania Roblot: Finite state complexity. Theor. Comput. Sci. 412(41): 5668-5677 (2011)

Alastair A. Abbott, Cristian S. Calude: Von Neumann Normalisation and Symptoms of Randomness: An Application to Sequences of Quantum Random Bits. UC 2011: 40-51

Cristian S. Calude, Grzegorz Rozenberg, Arto Salomaa (Eds.): Rainbow of Computer Science - Dedicated to Hermann Maurer on the Occasion of His 70th Birthday. Lecture Notes in Computer Science 6570, Springer 2011, isbn 978-3-642-19390-3

Cristian S. Calude, Jarkko Kari, Ion Petre, Grzegorz Rozenberg (Eds.): Unconventional Computation - 10th International Conference, UC 2011, Turku, Finland, June 6-10, 2011. Proceedings. Lecture Notes in Computer Science 6714, Springer 2011, isbn 978-3-642-21340-3

Alastair A. Abbott, Cristian S. Calude: Von Neumann Normalisation of a Quantum Random Number Generator. CoRR abs/1101.4711 (2011)

Alastair A. Abbott, Matthias Bechmann, Cristian S. Calude, Angelika Sebald: A Nuclear Magnetic Resonance Implementation of a Classical Deutsch-Jozsa Algorithm. CoRR abs/1110.0177 (2011)

Cristian S. Calude, Marius Zimand: Algorithmically independent sequences. Inf. Comput. 208(3): 292-308 (2010)

Cristian S. Calude, Ludwig Staiger: A note on accelerated Turing machines. Mathematical Structures in Computer Science 20(6): 1011-1017 (2010)

Cristian S. Calude, José Félix Costa: Preface to the Special Issue Unconventional Computing 2008. Natural Computing 9(4): 793-794 (2010)

Alastair A. Abbott, Cristian S. Calude: Understanding the Quantum Computational Speed-up via De-quantisation. DCM 2010: 1-12

Cristian Calude, Kai Salomaa, Tania Roblot: Finite-State Complexity and the Size of Transducers. DCFS 2010: 38-47

Cristian S. Calude, Vladimiro Sassone (Eds.): Theoretical Computer Science - 6th IFIP TC 1/WG 2.2 International Conference, TCS 2010, Held as Part of WCC 2010, Brisbane, Australia, September 20-23, 2010. Proceedings. IFIP Advances in Information and Communication Technology 323, Springer 2010, isbn 978-3-642-15239-9

Cristian S. Calude, Masami Hagiya, Kenichi Morita, Grzegorz Rozenberg, Jon Timmis (Eds.): Unconventional Computation - 9th International Conference, UC 2010, Tokyo, Japan, June 21-25, 2010. Proceedings. Lecture Notes in Computer Science 6079, Springer 2010, isbn 978-3-642-13522-4

Cristian S. Calude, Michael J. Dinneen, Monica Dumitrescu, Karl Svozil: Experimental Evidence of Quantum Randomness Incomputability. CoRR abs/1004.1521 (2010)

Cristian S. Calude, Elena Calude, Karl Svozil: Pi_1-Statements, Chaotic Systems and the Church-Turing Thesis. CoRR abs/1006.2951 (2010)

Cristian S. Calude, José Félix Costa: Introduction. Applied Mathematics and Computation 215(4): 1309-1310 (2009)

Cristian S. Calude, Nicholas J. Hay: Every computably enumerable random real is provably computably enumerable random. Logic Journal of the IGPL 17(4): 351-374 (2009)

Cristian S. Calude, Ludwig Staiger: On universal computably enumerable prefix codes. Mathematical Structures in Computer Science 19(1): 45-57 (2009)

Cristian S. Calude, José Félix Costa: Introduction. Natural Computing 8(3): 429-430 (2009)

Cristian S. Calude, Helmut Jürgensen, Ludwig Staiger: Topology on words. Theor. Comput. Sci. 410(24-25): 2323-2335 (2009)

Cristian S. Calude, Christine Müller: Formal Proof: Reconciling Correctness and Understanding. Calculemus/MKM 2009: 217-232

Cristian S. Calude: Information: The Algorithmic Paradigm. Formal Theories of Information 2009: 79-94

Cristian S. Calude, José Félix Costa, Nachum Dershowitz, Elisabete Freire, Grzegorz Rozenberg (Eds.): Unconventional Computation, 8th International Conference, UC 2009, Ponta Delgada, Azores, Portugal, September 7-11, 2009. Proceedings. Lecture Notes in Computer Science 5715, Springer 2009, isbn 978-3-642-03744-3

Cristian S. Calude, Gheorghe Paun: Foreword. Natural Computing 7(1): 1 (2008)

Cristian Calude: Incompleteness: A Personal Perspective. DCFS 2008: 14-24

Cristian S. Calude, André Nies, Ludwig Staiger, Frank Stephan: Universal Recursively Enumerable Sets of Strings. Developments in Language Theory 2008: 170-182

Cristian S. Calude, Marius Zimand: Algorithmically Independent Sequences. Developments in Language Theory 2008: 183-195

Cristian S. Calude: Simplicity via Provability for Universal Prefix-free Turing Machines. CSP 2008: 16-21

Cristian S. Calude, José Félix Costa, Rudolf Freund, Marion Oswald, Grzegorz Rozenberg (Eds.): Unconventional Computing, 7th International Conference, UC 2008, Vienna, Austria, August 25-28, 2008. Proceedings. Lecture Notes in Computer Science 5204, Springer 2008, isbn 978-3-540-85193-6

Cristian S. Calude, Marius Zimand: Algorithmically independent sequences. CoRR abs/0802.0487 (2008)

Cristian S. Calude, Nicholas J. Hay: Every Computably Enumerable Random Real Is Provably Computably Enumerable Random. CoRR abs/0808.2220 (2008)

Cristian S. Calude, Michael J. Dinneen: Exact Approximations of omega Numbers. I. J. Bifurcation and Chaos 17(6): 1937-1954 (2007)

Cristian S. Calude, Gheorghe Stefanescu, Marius Zimand: Combinatorics and Related Areas A Collection of Papers in Honour of the 65th Birthday of Ioan Tomescu. J. UCS 13(11): 1498-1500 (2007)

Cristian S. Calude, Rossella Lupacchini, Giorgio Sandri: Preface. Natural Computing 6(2): 73-74 (2007)

Mark Burgin, Cristian S. Calude: Preface. Theor. Comput. Sci. 383(2-3): 111-114 (2007)

Selim G. Akl, Cristian S. Calude, Michael J. Dinneen, Grzegorz Rozenberg, Todd Wareham (Eds.): Unconventional Computation, 6th International Conference, UC 2007, Kingston, Canada, August 13-17, 2007, Proceedings. Lecture Notes in Computer Science 4618, Springer 2007, isbn 978-3-540-73553-3

Cristian S. Calude, Ludwig Staiger, Sebastiaan Terwijn: On partial randomness. Ann. Pure Appl. Logic 138(1-3): 20-30 (2006)

Cristian S. Calude, Cezar Câmpeanu, Monica Dumitrescu: Automata Recognizing No Words: A Statistical Approach. Fundam. Inform. 73(1-2): 1-18 (2006)

Cristian S. Calude, Michael Stay: Natural halting probabilities, partial randomness, and zeta functions. Inf. Comput. 204(11): 1718-1739 (2006)

Cristian S. Calude, Michael A. Stay: Natural Halting Probabilities, Partial Randomness, and Zeta Functions. Kolmogorov Complexity and Applications 2006

Cristian S. Calude, Michael J. Dinneen, Gheorghe Paun, Grzegorz Rozenberg, Susan Stepney (Eds.): Unconventional Computation, 5th International Conference, UC 2006, York, UK, September 4-8, 2006, Proceedings. Lecture Notes in Computer Science 4135, Springer 2006, isbn 3-540-38593-2

Cristian S. Calude, Michael Stay: Natural Halting Probabilities, Partial Randomness, and Zeta Functions. CoRR abs/cs/0606033 (2006)

Cristian S. Calude, Michael Stay: Most Programs Stop Quickly or Never Halt. CoRR abs/cs/0610153 (2006)

Cristian S. Calude, Gheorghe Paun, Grzegorz Rozenberg: Contagious Creativity. Fundam. Inform. 64(1-4) (2005)

Cristian Calude, Sergiu Rudeanu: Proving as a Computable Procedure. Fundam. Inform. 64(1-4): 43-52 (2005)

Cristian Calude: Preface. Int. J. Found. Comput. Sci. 16(4): 623-624 (2005)

Cristian S. Calude, Hajime Ishihara: Constructivity, Computability, and Logic A Collection of Papers in Honour of the 60th Birthday of Douglas Bridges. J. UCS 11(12): 1863-1865 (2005)

Cristian S. Calude, Ludwig Staiger: Generalisations of disjunctive sequences. Math. Log. Q. 51(2): 120-128 (2005)

Cristian Calude, Michael J. Dinneen, Gheorghe Paun, Mario J. Pérez-Jiménez, Grzegorz Rozenberg (Eds.): Unconventional Computation, 4th International Conference, UC 2005, Sevilla, Spain, October 3-7, 2005, Proceedings. Lecture Notes in Computer Science 3699, Springer 2005, isbn 3-540-29100-8

Cristian Calude, Elena Calude, Solomon Marcus: Passages of Proof. Bulletin of the EATCS 84: 167-188 (2004)

Joshua J. Arulanandham, Cristian Calude, Michael J. Dinneen: A fast natural algorithm for searching. Theor. Comput. Sci. 320(1): 3-13 (2004)

Cristian Calude, Solomon Marcus: Mathematical Proofs at a Crossroad? Theory Is Forever 2004: 15-28

Joshua J. Arulanandham, Cristian Calude, Michael J. Dinneen: Balance Machines: Computing = Balancing. Aspects of Molecular Computing 2004: 36-48

Cristian Calude: Algorithmic Randomness, Quantum Physics, and Incompleteness. MCU 2004: 1-17

Cristian Calude, Elena Calude, Michael J. Dinneen (Eds.): Developments in Language Theory, 8th International Conference, DLT 2004, Auckland, New Zealand, December 13-17, 2004, Proceedings. Lecture Notes in Computer Science 3340, Springer 2004, isbn 3-540-24014-4

Cristian Calude, Solomon Marcus, Ludwig Staiger: A topological characterization of random sequences. Inf. Process. Lett. 88(5): 245-250 (2003)

Cristian Calude, Elena Calude, Michael J. Dinneen: What is the Value of Taxicab(6)? J. UCS 9(10): 1196-1203 (2003)

Cristian Calude, Michael J. Dinneen, Vincent Vajnovszki (Eds.): Discrete Mathematics and Theoretical Computer Science, 4th International Conference, DMTCS 2003, Dijon, France, July 7-12, 2003. Proceedings. Lecture Notes in Computer Science 2731, Springer 2003, isbn 3-540-40505-4

Joshua J. Arulanandham, Cristian Calude, Michael J. Dinneen: Bead-Sort: A Natural Sorting Algorithm. Bulletin of the EATCS 76: 153-161 (2002)

Cristian Calude, Elena Calude: The Bridge Crossing Problem. Bulletin of the EATCS 77: 180-190 (2002)

Cristian S. Calude, Michael J. Dinneen, Chi-Kou Shu: Computing a Glimpse of Randomness. Experimental Mathematics 11(3): 361-370 (2002)

Cristian Calude, Kai Salomaa, Sheng Yu: Advances and Trends in Automata and Formal Languages A Collection of Papers in Honour of the 60th Birthday of Helmut Jürgensen - J.UCS Special Issue. J. UCS 8(2): 117-118 (2002)

Cristian Calude, Kai Salomaa, Sheng Yu: Additive Distances and Quasi-Distances Between Words. J. UCS 8(2): 141-152 (2002)

Cristian Calude: A characterization of c.e. random reals. Theor. Comput. Sci. 271(1-2): 3-14 (2002)

Cristian Calude: Chaitin Omega numbers, Solovay machines, and Gödel incompleteness. Theor. Comput. Sci. 284(2): 269-277 (2002)

Cristian Calude, Michael J. Dinneen, Ferdinand Peper (Eds.): Unconventional Models of Computation, Third International Conference, UMC 2002, Kobe, Japan, October 15-19, 2002, Proceedings. Lecture Notes in Computer Science 2509, Springer 2002, isbn 3-540-44311-8

Cristian Calude, Hajime Ishihara, Takeshi Yamaguchi: Coding with Minimal Programs. Int. J. Found. Comput. Sci. 12(4): 479-490 (2001)

Cristian Calude, Peter Hertling, Bakhadyr Khoussainov, Yongge Wang: Recursively enumerable reals and Chaitin Omega numbers. Theor. Comput. Sci. 255(1-2): 125-149 (2001)

Cristian S. Calude, Elena Calude, Peter Kay: Liars, Demons, and Chaos. Words, Semigroups, and Transductions 2001: 33-46

Cristian S. Calude, Elena Calude, Karl Svozil: Computational complementarity for probabilistic automata. Where Mathematics, Computer Science, Linguistics and Biology Meet 2001: 99-113

Cristian Calude, Elena Calude: Automata: From Uncertainty to Quantum. Developments in Language Theory 2001: 1-14

Ioannis Antoniou, Cristian Calude, Michael J. Dinneen (Eds.): Unconventional Models of Computation, UMC'2K, Proceedings of the Second International Conference, Brussel, Belgium, 13-16 December 2000. Springer 2001, isbn 1-85233-415-0

Cristian Calude, Gheorghe Paun, Grzegorz Rozenberg, Arto Salomaa (Eds.): Multiset Processing, Mathematical, Computer Science, and Molecular Computing Points of View [Workshop on Multiset Processing, WMP 2000, Curtea de Arges, Romania, August 21-25, 2000]. Lecture Notes in Computer Science 2235, Springer 2001, isbn 3-540-43063-6

Cristian S. Calude, Michael J. Dinneen, Karl Svozil: Reflections on quantum computing. Complexity 6(1): 35-37 (2000)

Cristian S. Calude, Gheorghe Paun: Computing with cells and atoms in a nutshell. Complexity 6(1): 38-48 (2000)

Cristian Calude, Gheorghe Stefanescu: Automata, Logic, and Computability: J.UCS Special Issue Dedicated to Professor Sergiu Rudeanu Festschrift. J. UCS 6(1): 1-2 (2000)

Cristian Calude, Elena Calude, Bakhadyr Khoussainov: Finite nondeterministic automata: Simulation and minimality. Theor. Comput. Sci. 242(1-2): 219-235 (2000)

Cristian S. Calude, Elena Calude, Karl Svozil: Quantum Correlations Conundrum: An Automata-Theoretic Approach. Recent Topics in Mathematical and Computational Linguistics 2000: 55-67

Cristian Calude, Richard J. Coles: Program-Size Complexity of Initial Segments and Domination Reducibility. Jewels are Forever 1999: 225-237

Cristian Calude, Elena Calude: Bisimulations and behaviour of nondeterministic automata. Developments in Language Theory 1999: 60-70

Cristian Calude, Kai Salomaa, Sheng Yu: Metric Lexical Analysis. WIA 1999: 48-59

Cristian S. Calude, John L. Casti: Introduction to unconventional models of computation. Complexity 4(1): 13 (1998)

Cristian Calude, Elena Calude, Catalina Stefanescu: Computational Complementarity for Mealy Automata. Bulletin of the EATCS 66: 139-149 (1998)

Cristian Calude, Peter Hertling: Computable Approximations of Reals: An Information-Theoretic Analysis. Fundam. Inform. 33(2): 105-120 (1998)

Cristian S. Calude, Marjo Lipponen: Computational Complementarity and Sofic Shifts. CATS 1998: 277-290

Cristian Calude, Peter Hertling, Bakhadyr Khoussainov, Yongge Wang: Recursively Enumerable Reals and Chaitin Omega Numbers. STACS 1998: 596-606

Cristian Calude, Elena Calude, Bakhadyr Khoussainov: Deterministic Automata: Simulation, Universality and Minimality. Ann. Pure Appl. Logic 90(1-3): 263-276 (1997)

Cristian S. Calude: A genius's story: Two books on Gödel. Complexity 3(2): 11-15 (1997)

Cristian Calude, Sheng Yu: Language-theoretic Complexity of Disjunctive Sequences. Discrete Applied Mathematics 80(2-3): 203-209 (1997)

Cristian Calude, Peter Hertling, Bakhadyr Khoussainov: Do the Zeros of Riemann's Zeta-Function Form a Random Sequence? Bulletin of the EATCS 62 (1997)

Douglas S. Bridges, Cristian Calude, Michael J. Dinneen, Bakhadyr Khoussainov: Logic in Computer Science. J. UCS 3(11): 1133 (1997)

Cristian Calude, André Nies: Chaitin Omega Numbers and Strong Reducibilities. J. UCS 3(11): 1162-1166 (1997)

Cristian Calude, Ioan Tomescu: Optimum Extendible Prefix Codes. J. UCS 3(11): 1167-1179 (1997)

Andris Ambainis, Kalvis Apsitis, Cristian Calude, Rusins Freivalds, Marek Karpinski, Tomas Larfeldt, Iveta Sala, Juris Smotrovs: Effects of Kolmogorov Complexity Present in Inductive Inference as Well. ALT 1997: 244-259

Cristian S. Calude, Elena Calude, Bakhadyr Khoussainov: Deterministic Automata: Simulation, Universality and Minimality. Extended Abstract. Developments in Language Theory 1997: 519-537

Cristian Calude: The Finite, The Unbounded and The Infinite. J. UCS 2(5): 242-244 (1996)

Cristian Calude, Cristian Grozes: Kraft-Chaitin Inequality Revisited. J. UCS 2(5): 306-310 (1996)

Cristian Calude: Algorithmic Information Theory: Open Problems. J. UCS 2(5): 439-441 (1996)

Cristian Calude, Marius Zimand: Effective Category and Measure in Abstract Complexity Theory. Theor. Comput. Sci. 154(2): 307-327 (1996)

Gregory J. Chaitin, Asat Arslanov, Cristian Calude: Program-size Complexity Computes the Halting Problem. Bulletin of the EATCS 57 (1995)

Cristian Calude: What Is a Random String? J. UCS 1(1): 48-66 (1995)

Cristian Calude, Marius Zimand: Effective Category and Measure in Abstract Complexity Theory (Extended Abstract). FCT 1995: 156-170

Cristian Calude, Monica Tataram: Three Theories of Computational Complexity Extended Abstract. Sci. Ann. Cuza Univ. 3: 45-52 (1994)

Cristian Calude, Hermann A. Maurer, Arto Salomaa: Journal of Universal Computer Science. J. UCS 0(0): 109-115 (1994)

Douglas S. Bridges, Cristian Calude: On Recursive Bounds for the Exceptional Values in Speed-Up. Theor. Comput. Sci. 132(2): 387-394 (1994)

Cristian Calude, Helmut Jürgensen: Randomness as an Invariant for Number Representations. Results and Trends in Theoretical Computer Science 1994: 44-66

Cristian Calude, Cezar Câmpeanu: Note on the Topological Structure of Random Strings. Theor. Comput. Sci. 112(2): 383-390 (1993)

Cristian Calude: Borel Normality and Algorithmic Randomness. Developments in Language Theory 1993: 113-129

Cristian Calude, Arto Salomaa: Algorithmically Coding the Universe. Developments in Language Theory 1993: 472-492

Cristian Calude, Gabriel Istrate: Determining and Stationary Sets for Some Classes of Partial Recursive Functions. Theor. Comput. Sci. 82(1): 151-155 (1991)

Cristian Calude: Relativized Topological Size of Sets of Partial Recursive Functions. Theor. Comput. Sci. 87(2): 347-352 (1991)

Cristian Calude, Dragos Vaida: Ehrenfeucht Test Set Theorem and Hilbert Basis Theorem: A Constructive Glimpse. MFCS 1989: 177-184

Cristian Calude: Super-Exponentials Nonprimitive Recursive, but Rudimentary. Inf. Process. Lett. 25(5): 311-316 (1987)

Cristian Calude: Note on Ehrenfeucht's conjecture and Hilbert's basis theorem. Bulletin of the EATCS 29: 18-21 (1986)

Cristian Calude, Ion Chitescu: A class of nuniversal P Marti-Löf tests. Bulletin of the EATCS 23: 15-21 (1984)

Cristian Calude, Gheorghe Paun: Independent Instances for Some Undecidable Problems. ITA 17(1): 49-54 (1983)

Cristian Calude, Gheorghe Paun: Global syntax and semantics for recursively enumerable languages. Fundam. Inform. 4(2): 245-254 (1981)