Full Papers in Refereed Journals

  1. A. Abbott, C. S. Calude, K. Svozil. A quantum random number generator certified by value indefiniteness, Mathematical Structures in Computer Science, submitted December 2010.

  2. C. S. Calude, K. Salomaa, T. K. Roblot. State-size hierarchy for FS-complexity, International Journal of Foundations of Computer Science, submitted November 2010.

  3. A. A. Abbott, C. S. Calude. Understanding the quantum computational speed-up via de-quantisation, Mathematical Structures in Computer Science, submitted October 2010.

  4. C. S. Calude, A. Nies, L. Staiger and F. Stephan. Universal recursively enumerable sets of strings, Theoretical Comput. Sci., accepted 2011, DOI: 10.1016/j.tcs.2011.01.002.

  5. C. S. Calude, M. Cavaliere, R. Mardare. An observer-based de-quantisation of Deutsch’s Algorithm, International Journal of Foundations of Computer Science 22, 1 (2011), 191-202.

  6. C. S. Calude, E. Calude and K. Svozil. The complexity of proving chaoticity and the Church-Turing Thesis, Chaos 20 037103 (2010), 1-5.

  7. C. S. Calude, N. J. Hay, F. Stephan. Representation of left-computable ε-random reals, Journal of Computer and System Sciences, 2010, DOI: 10.1016/j.jcss.2010.08.0001.

  8. C. S. Calude, M. J. Dinneen, Monica Dumitrescu, K. Svozil. Experimental evidence of quantum randomness incomputability, Physical Review A, 82, 022102 (2010), 1-8.

  9. C. S. Calude, L. Staiger. A note on accelerated Turing machines, Mathematical Structures in Computer Science, 20 (2010), 1011-1017. DOI: 10.1017/S0960129510000344.

  10. C. S. Calude, Elena Calude. The complexity of the Four Colour Theorem, LMS J. Comput. Math. 13 (2010), 414-425.

  11. C. S. Calude. Simplicity via provability for universal prefix-free Turing machines, Theoretical Comput. Sci., 412 (2010), 178-182. DOI: 10.1016/j.tcs.2010.08.002.

  12. C. S. Calude, Elena Calude. Evaluating the Complexity of Mathematical Problems. Part 2, Complex Systems 18 (2010), 387-401.

  13. C. S. Calude, G. J. Chaitin. What is ... a halting probability? Notices of the AMS 57, 2 (2010), 236-237.

  14. C. S. Calude, M. Zimand. Algorithmically independent sequences, Information and Compu- tation 208 (2010), 292-308.

  15. C. S. Calude, Elena Calude. Evaluating the Complexity of Mathematical Problems. Part 1, Complex Systems 18(2009), 267-285.

  16. C. S. Calude, N. J. Hay. Every computably enumerable random real is provably computably enumerable random, Logic Journal of the IGPL, June, 2009, 24 pp, doi:10.1093/jigpal/jzp015.

  17. C.S. Calude, H. Juergensen, L. Staiger. Topology on words, Theoretical Comput. Sci. 410 (2009) 2323--2335.

  18. C.S. Calude and L. Staiger. On universal computably enumerable prefix codes, Mathematical Structures in Computer Science 19 (2009), 45--57.

  19. C. S. Calude, K. Svozil. Quantum randomness and value indefiniteness, Advanced Science Letters 1 (2008), 165-168.

  20. C. S. Calude, M. A. Stay. Most programs stop quickly or never halt, Advances in Applied Mathematics, 40 (2008), 295-308.

  21. C. S. Calude. De-quantising the solution of Deutsch's problem, International Journal of Quantum Information 5, 4(2007), 1-7.

  22. C. S. Calude, M. J. Dinneen. Exact approximations of omega numbers, Int. Journal of Bifurcation & Chaos, 17, 6 (2007), 1937-1954.

  23. C. S. Calude, G. J. Chaitin. A dialogue on mathematics & physics, The Rutherford Journal: The New Zealand Journal for the History and Philosophy of Science and Technology, Vol. 2, 2006-2007.

  24. C. S. Calude, M. A. Stay. Natural halting probabilities, partial randomness, and Zeta functions, Information and Computation 204 (2006), 1718-1739.

  25. C. S. Calude, Elena Calude, M. J. Dinneen. A new measure of the difficulty of problems, Journal for Multiple-Valued Logic and Soft Computing 12 (2006), 285-307.

  26. C. S. Calude, C. Campeanu, Monica Dumitrescu. Automata recognizing no words: A statistical approach, Fundamenta Informaticae 72 (2006), 1-18.

  27. C. S. Calude, L. Staiger, S. A. Terwijn. On partial randomness, Annals of Applied and Pure Logic, 138 (2006), 20-30.

  28. C. S. Calude, M. A. Stay. From Heisenberg to G\"odel via Chaitin, International Journal of Theoretical Physics 44, 7 (2005), 1053-1065.

  29. C.S. Calude, H. Juergensen. Is Complexity a Source of Incompleteness?, Advances in Applied Mathematics, 35 (2005), 1-15.

  30. C. S. Calude, S. Rudeanu. Proving as a computable procedure, Fundamenta Informaticae, 64 (2005), 1-10.

  31. C. S. Calude, L. Staiger, K. Svozil. Randomness Relative to Cantor Expansions, Comm. Nonlinear Science Numerical Simulation, 10/8 (2005), 921-930.

  32. C. S. Calude, L. Staiger. Generalisations of disjunctive sequences, Math. Log. Quart., 51, 2 (2005), 120-128.

  33. C. S. Calude, J. L. Casti. The jumble cruncher, The New Scientist 25 September 2004, 36-37: page 36, page 37. Posted also by ID Quantique.

    34. New Scientist








  34. C.S. Calude, Elena Calude, S. Marcus. Passages of proof, Bull. Eur. Assoc. Theor. Comput. Sci. EATCS 84 (2004), 167-188.

  35. C. S. Calude, G. Paun. Bio-steps beyond Turing, BioSystems 77 (2004), 175-194.

  36. J. J. Arulanandham, C. S. Calude, M. J. Dinneen. A fast natural algorithm for searching, Theoret. Comput Sci., Natural Computing, 320, 1 (2004), 3-13. Among TCS most requested articles Jan-Aug 2004.

  37. C.S. Calude, S. Marcus, L. Staiger. A topological characterization of random sequences,  Inform. Process. Lett. 88 (2003), 245-250.

  38. J. J. Arulanandham,  C.S. Calude,  M.J. Dinneen. Solving SAT with bilateral computing,  Romanian Journal of Information Science and Technology 6, 1-2 (2003), 9-18.

  39. C.S. Calude, Elena Calude, M.J. Dinneen. What is the value of Taxicab(6)? , J. UCS 9, 10 (2003), 1196-1203.

  40. C. S. Calude, B. Pavlov. Coins, quantum measurements, and Turing's barrier, Quantum Information Processing 1, 1-2 (2002), 107-127.

  41. C. S. Calude. Incompleteness, complexity, randomness and beyond, Journal for Artificial Intelligence, Philosophy and Cognitive Science, 12, 4 (2002), 503-517. 

  42. C. S. Calude, M. J. Dinneen and C.-K. Shu. Computing a glimpse of randomness, Experimental Mathematics,  2 (2002), 369-378. Slides

  43. C. S. Calude, K. Salomaa, S. Yu. Additive distance and quasi-distances between words, J. UCS 8, 2 (2002), 141-152.

  44. J. J. Arulanandham, C. S. Calude, M. J. Dinneen. Bead-Sort: A natural sorting algorithm, EATCS Bull. 76 (2002), 76 (2002), 153-162. Simulation of the Bead-Sort Algorithm with just one line MGS code

  45. C. S. Calude, Monica Dumitrescu. Entropic measures, Markov information sources and complexity, Appl. Math. Comput. 132, 2--3 (2002), 369-384.

  46. C. S. Calude. Chaitin Omega numbers, Solovay machines and incompleteness, Theoret. Comput. Sci. 284 (2002), 269-277. Top 25 of most downloaded TCS articles for April-August 2002. 

  47. C. S. Calude. A characterization of c.e. random reals, Theoret. Comput. Sci., 217 (2002), 3-14. 

  48. C. S. Calude, H. Ishihara, T. Yamaguchi. Minimal programs are almost optimal, International Journal of Foundations of Computer Science 12, 4 (2001), 479-489.

  49. C. S. Calude, P. Hertling, B. Khoussainov, Y. Wang. Recursively enumerable reals and Chaitin W numbers, Theoret. Comput. Sci., 255 (2001), 125-149.

  50. C. S. Calude, P. Hertling, H. Jürgensen, K. Weihrauch. Randomness on full shift spaces, Chaos, Solitons & Fractals, 12/3 (2001), 491-503.

  51. C. S. Calude, G. Paun, Monica Tatarâm. A glimpse into natural computing, J. Multi Valued Logic, 7 (2001), 1-28.

  52. C. S. Calude, Elena Calude, Terry Chiu, Monica Dumitrescu, R.  Nicolescu. Testing computational complementarity for Mermin automata, J. Multi Valued Logic, 6 (2001), 47-65.

  53. C. S. Calude, P. Hertling, H. Jürgensen, K. Weihrauch. Randomness on full shift spaces, Chaos, Solitons & Fractals, 12/3 (2001), 491-503.

  54. C. S. Calude, M. J. Dinneen, K. Svozil. Reflections on quantum computing, Complexity, 6, 1 (2000), 35-37.

  55. C. S. Calude, G. Paun. Computing with cells and atoms in a nutshell, Complexity, 6, 1 (2000), 38-48.

  56. C. S. Calude, Elena Calude, B. Khoussainov. Finite nondeterministic automata: Simulation and minimality, Theoret. Comput. Sci. 242, 1-2 (2000), 219-235.

  57. C. S. Calude, Marjo Lipponen. Computational complementarity and shift spaces, Chaos, Solitons & Fractals 11 (2000), 315-319.

  58. C. S. Calude, G. J. Chaitin. Randomness everywhere, Nature, 400, 22 July (1999), 319-320.

  59. C. S. Calude, F. W. Meyerstein. Is the universe lawful ? Chaos, Solitons & Fractals 10, 6 (1999), 1075-1084.

  60. C. S. Calude, P. H. Hertling, K. Svozil. Embedding quantum universes into classical ones, Foundations of Physics, 29, 3 (1999), 349-379.

  61. D. Bridges, C. Calude, B. Pavlov, D. Stefanescu. The inverse function theorem-a constructive approach, Chaos, Solitons & Fractals 10, 6 (1999), 927-934.

  62. C. Calude, S. Marcus, D. Stefanescu. The Creator versus its creation. From Scotus to Gödel, Collegium Logicum. Annals of the Kurt-Gödel-Society, Vol. 3, Institute of Computer Science, AS CR Prague, Vienna, 1999, 1-10.

  63. C. S. Calude, T. Zamfirescu. Most numbers obey no probability laws, Publicationes Mathematicae Debrecen, Tome 54 Supplement (1999), 619-623.

  64. C. S. Calude, J. L. Casti. Silicon, molecules, or photons ? Complexity 4, 1, (1998), 13.

  65. C. S. Calude, Elena Calude, Catalina Stefanescu. Computational complementarity for Mealy automata, EATCS Bull. 66 (1998), 139-149.

  66. C. S. Calude, P. Hertling. Computable approximations of reals: An information-theoretic analysis, Fundamenta Informaticae  33 (1998), 1-16.

  67. C. S. Calude, J. L. Casti. Parallel thinking, Nature 392, 9 April (1998), 549-551.

  68. C. S. Calude, J. L. Casti, P. B. Gibbons, Marjo Lipponen. Unconventional models of computation: A conventional report, Complexity 3, 4 (1998), 8-11.

  69. C. S. Calude, P. H. Hertling, K. Svozil. Kochen-Specker theorem: Two geometric proofs, Tatra Mt. Math. Publ. 15 (1998), 133-142.

  70. C. Calude, T. Zamfirescu. The typical number is a lexicon, New Zealand Journal Math. 27 (1998), 7-13.

  71. C. S. Calude. A genius's story: Two books on Gödel. The life and works of a master logician, Complexity 3, 2 (1997), 1-5.

  72. C. S. Calude, A. Nies. Chaitin W numbers and strong reducibilities, J. UCS 3 (1997), 1161-1166.

  73. C. S. Calude, I. Tomescu. Optimum extendible prefix codes, J. UCS 3 (1997), 1167-1179.

  74. C. Calude, Elena Calude, B. Khoussainov. Deterministic automata: simulation, universality and minimality, Annals of Applied and Pure Logic 90, 1-3 (1997), 263-276.

  75. C. Calude, P. Hertling, B. Khoussainov. Do the zeros of Riemann's zeta-function form a random sequence ? EATCS Bull. 62 (1997), 199-207.

  76. C. Calude, Elena Calude, K. Svozil, S. Yu. Physical versus computational complementarity I, International Journal of Theoretical Physics 36 (1997), 1495-1523.

  77. C. Calude, S. Yu. Language-theoretic complexity of disjunctive sequences, Discrete Appl. Mathematics 80 (1997), 199-205.

  78. C. Calude. The finite, the unbounded and the infinite, J. UCS 2 (1996), 242-244.

  79. C. Calude, C. Grozea. Kraft-Chaitin inequality revisited, J. UCS 2 (1996), 306-310. (MR 97c:68070)

  80. C. Calude. Algorithmic information theory: Open problems, J. UCS 2 (1996), 439-441. (MR 97f:68080)

  81. C. Calude, C. Câmpeanu. Are binary codings universal ?, Complexity 1, 15 (1996), 47-50. (MR 97a:68086)

  82. C. Calude, M. Zimand. Effective category and measure in abstract complexity theory, Theoret. Comput. Sci. 154 (1996), 307-327. (MR 97a:68060)

  83. A. Arslanov, C. Calude. Program-size complexity computes the halting problem, EATCS Bull. 57 (1995), 199-200. [Another solution by G. J. Chaitin]

  84. C. Calude. What is a random string ? J. UCS, Vol. 1,1 (1995), 48-66.

  85. C. Calude, Monica Tataram. Three theories of computational complexity. Extended abstract, An. Univ. Iasi, Inf. 3 (1994), 45-52.

  86. C. Calude, H. Jürgensen, M. Zimand. Is independence an exception ?, Appl. Math. Comput. 66 (1994), 63-76. (MR 96c:03113, Zbl 822# 03024)

  87. D. S. Bridges, C. Calude. On recursive bounds for the exceptional values in speed-up, Theoret. Comput. Sci. 132 (1994), 387-394. (MR 95f: 03059, Zbl 807#03026)

  88. C. Calude, C. Câmpeanu. Note on the topological structure of random strings, Theoret. Comput. Sci. 112 (1993), 383-390. (MR 94d: 68081, Zbl 781#68073)

  89. C. Calude, G. Istrate, M. Zimand. Recursive Baire classification and speedable functions, Z. Math. Logik Grundlang. Math. 3 (1992), 169-178. (MR 94j: 03083, Zbl 798#03042)

  90. C. Calude. Algorithmic complexity: A topological point of view, Singularité 2, 10 (1991), 28-29. [With a comment and a list of open problems due to the editor] (in French)

  91. C. Calude. Relativized topological size of sets of partial recursive functions, Theoret. Comput. Sci. 87 (1991), 347-352. (MR 92h: 03060, Zbl 814#0303)

  92. C. Calude, G. Istrate. Determining and stationary sets for some classes of partial recursive functions, Theoret. Comput. Sci. 82 (1991), 151-155. (MR 92g: 03065, Zbl 723#03024)

  93. C. Calude, Lila Sântean. On a theorem of Günter Asser, Z. Math. Logik Grundlang. Math. 36 (1990), 143-147. [With a comment by G. Asser] (MR 91h: 03049, Zbl 687#03019, 698#03031)

  94. C. Calude, Eva Kurta. On Kraft-Chaitin inequality, Rev. Roumaine Math. Pures Appl. 35 (1990), 597-604. (MR 92C: 94004, Zbl 731#68056)

  95. C. Calude, I. Chitescu. Qualitative properties of P. Martin-Löf random sequences, Boll. Unione Mat. Ital. VII, Ser. B3, 240 (1989), 229-240. (MR 91a: 68147, Zbl 674#03013)

  96. C. Calude, I. Chitescu. Upper limitation of Kolmogorov complexity and universal P. Martin-Löf tests, Journal of Computational Mathematics 1 (1989), 61-70. (MR 91a: 68147, Zbl 673#68028)

  97. C. Calude, S. Marcus. Sudan's recursive and non-primitive recursive function: a retrospective look, An. Univ. Bucuresti, Mat.-Inf. 2 (1989), 25-30. (MR 92a: 03060, Zbl 741#03020)

  98. C. Calude, I. Chitescu. Random sequences: some topological and measure-theoretical properties, An. Univ. Bucuresti, Mat.-Inf. 2 (1988), 27-32. (MR 89m: 60004, Zbl 688#60001)

  99. C. Calude, I. Chitescu. Random sequences according to P. Martin-Löf, Found. Control Engrg. 12, 3 (1987), 75-84. (MR 89e: 58059, Zbl 632#03041)

  100. C. Calude. Super-exponentials non-primitive recursive, but rudimentary, Inform. Process. Lett. 25 (1987), 311-315. (MR 88j: 03026, Zbl 632#03036)

  101. C. Calude. Note on Ehrenfeucht's conjecture and Hilbert's basis theorem, EATCS Bull. 29 (1986), 18-22.

  102. S. Buzeteanu, C. Calude. Functions having the graph in the n-th Grzegorczyk class, Found. Control Engrg. 11 (1986), 61-67. (MR 88f: 03034, Zbl 625#03020)

  103. C. Calude, I. Chitescu, L. Staiger. P. Martin-Löf tests: representability and embeddability, Rev. Roumaine Math. Pures Appl. 30 (1985), 719-732. (MR 88i: 68043, Zbl 587#03032)

  104. C. Calude, I. Chitescu. A combinatorial characterization of sequential P. Martin-Löf tests, Internat. J. Comput. Math. 17 (1985), 53-64. (Zbl 562#03020)

  105. C. Calude, M. Zimand. A relation between correctness and randomness in the computation of probabilistic algorithms, Internat. J. Comput. Math. 16 (1984), 47-53. (MR 86e: 68052, Zbl 552#68051)

  106. C. Calude, I. Chitescu. A class of universal P. Martin-Löf tests, EACTS Bull. 23 (1984), 15-22.

  107. C. Calude, I. Chitescu. Representability of recursive P. Martin-Löf tests, Kybernetika (Prague) 19 (1983), 526-536. (MR 85h: 03040, Zbl 529#03021)

  108. C. Calude. A simple non-uniform operation, EATCS Bull. 20 (1983), 40-46.

  109. C. Calude, Elena Calude. On some discrete metrics, Bull. Math. Soc. Sci. Math. R. S. Roumanie (N. S.) 27 (75) (1983), 213-216. (MR 85f: 54057, Zbl 539#54019)

  110. C. Calude, Gh. Paun. Independent instances for some undecidable problems, RAIRO Inform. Theor. 17 (1983), 49-54. (MR 85d: 03087, Zbl 517#03022)

  111. C. Calude. On a class of independent problems related to Rice theorem, ACM SIGACT News 15 (1983), 53-57. (Zbl 535#03020)

  112. C. Calude, Monica Tataram. Universal sequences of primitive recursive functions, Rev. Roumaine Math. Pures Appl. 28 (1983), 381-389. (MR 85c: 03016, Zbl 535#03017)

  113. C. Calude, I. Chitescu. On representability of P. Martin-Löf tests, Kybernetika (Prague) 19 (1983), 42-47. (MR 85h: 03040, Zbl 529#03020)

  114. C. Calude. Topological size of sets of partial recursive functions, Z. Math. Logik Grundlang. Math. 28 (1982), 455-462. (MR 85i: 03134, Zbl 495#03022)

  115. C. Calude, I. Chitescu. On Per Martin-Löf random sequences, Bull. Math. Soc. Sci. Math. R. S. Roumanie (N.S.) 26 (74) (1982), 217-221. (MR 84g: 03073, Zbl 495#03026)

  116. C. Calude, I. Chitescu. Random strings according to A. N. Kolmogorov and P. Martin-Löf. Classical approach, Found. Control Engrg. 7 (1982), 73-85. (MR 84h: 60008, Zbl 521#03024)

  117. C. Calude, I. Chitescu. Strong noncomputability of random strings, Internat. J. Comput. Math. 11 (1982), 43-45. (MR 83h: 68066, Zbl 486#03026)

  118. C. Calude. Note on a hierarchy of primitive recursive functions, Rev. Roumaine Math. Pures Appl. 27 (1982), 935-936. (MR 85b: 03065, Zbl 495#03027)

  119. C. Calude, Elena Calude. A metrical method for multicriteria decision making, St. Cerc. Mat. 34 (1982), 223-234. (in Romanian) (Zbl 523#90004)

  120. C. Calude, Gh. Paun. On the adequacy of a grammatical model of the brain,  Rev. Roumaine Ling. 27 (1982), 343-351. (Romanian Contributions to the XIII-th International Congress of Linguistics, Tokyo, 1982, Section Linguistics and the Computer)

  121. M. Andrasiu, C. Calude, Gh. Paun. Possibilities of multicriteria decision making, St. Cerc. Mat. 34 (1982), 87-103. (in Romanian) (Zbl 505#90004)

  122. C. Calude, V. Vieru. An iterative normal form for the partial recursive functions, Found. Control Engrg. 6 (1981), 133-144. (MR 85b: 03064, Zbl 503#68034)

  123. C. Calude, Gh. Paun. Global syntax and semantics for recursively enumerable languages, Fund. Inform. 4 (1981), 245-254. (MR 83h: 68133, Zbl 473#68068)

  124. C. Calude. Darboux property and primitive recursive functions, Rev. Roumaine Math. Pures Appl. 26 (1981), 1187-1192. (MR 84h: 03100, Zbl 481#03028)

  125. C. Calude, V. Vieru. A note on Knuth's iterated powers, An. Stiin. Univ. ``Alex.I.Cuza'', Iasi, Sect. I Mat. 27 (1981), 253-255. (MR 84m: 03062, Zbl 473#03035)

  126. C. Calude, Elena Calude. On the ``rationality'' of Onicescu's method for multicriteria making, Rev. de Statistica 30 (1981), 58-60. (in Romanian)

  127. C. Calude, S. Marcus. Man-computer communication, Rev. Roumaine Ling. 26 (1981), 103-112.

  128. C. Calude, Gh. Paun. The absence of contextual ambiguities in programming languages, Rev. Roumaine Ling. Cahiers Ling. Theor. Appl. 18 (1981), 91-110.

  129. M. Andrasiu, C. Calude, Gh. Paun. Some extensions of the multicriteria decision problem, Rev. de Statistica 29 (1980), 43-49. (in Romanian)

  130. C. Calude, S. Marcus, I. Tevy. Recursive properties of Sudan function, Rev. Roumaine Math. Pures Appl. 25 (1980), 503-507. (MR 81f: 03053, Zbl 444#03021)

  131. C. Calude, S. Marcus, I. Tevy. The first example of a recursive function which is not primitive recursive, Historia Math. 9 (1979), 380-384. (MR 80i: 03053, Zbl 426#03042)

  132. C. Calude, V. E. Cazanescu. On topologies generated by Moisil resemblance relations, Discrete Math. 25 (1979), 109-115. (MR 80i: 54003, Zbl 412#54010)

  133. C. Calude, S. Marcus, Gh. Paun. The universal grammar as a hypothetical brain, Rev. Roumaine Ling. 27 (1979), 479-489.

  134. C. Calude. Categorical methods in computability theory II, St. Cerc. Mat. 30 (1978), 361-383. (in Romanian) (MR 80m: 03110a, Zbl 405#03025)

  135. C. Calude. Categorical methods in computability theory I, St. Cerc. Mat. 30 (1978), 253-277. (in Romanian) (MR 80m: 03110b, Zbl 381#03028)

  136. C. Calude, Brândusa Fântâneanu. On recursive, non-primitive recursive functions, Bull. Math. Soc. Sci. Math. R. S. Roumanie 22 (1978), 255-258. (MR 80b: 03052, Zbl 399#03025)

  137. C. Calude. On the category of recursive languages, Mathematica (Cluj) 19 (42), (1978), 29-32. (MR 80b: 03056, Zbl 384#03029)

  138. C. Calude. A grammatical construction of Gödel numberings, C. R. Acad. Sci. Paris Ser. I Math. 284 (1977), 525-526. (in French) (MR 55#87, Zbl 347#02026)

  139. C. Calude. On the compatibility between the analytic and generative hierarchies of formal languages, Rev. Roumaine Math. Pures Appl. 22 (1977), 437-439. (MR 56#7334, Zbl 358#68105)

  140. C. Calude. On some topological properties of semilattice ordered semigroups, Bull. Math. Soc. Sci. Math. R. S. Roumanie 19 (1976), 3-10. (MR 56#15523, Zbl 347#06020)

  141. C. Calude. An axiomatics for a deontic logic with an infinity of truth values, Rev. Roumaine Math. Pures Appl. 21 (1976), 267-273. (in French) (MR 53#7728, Zbl 347#02019)

  142. C. Calude. On the metrizability of a free monoid, Discrete Math. 16, 19 (1976), 307-310. (MR 58#22347, Zbl 337#68053)

  143. C. Calude. On contextual distances in mathematical linguistics, St. Cerc. Mat. 28 (1976), 31-35. (in Romanian) (MR 53#12092, Zbl 339#68050)

  144. C. Calude. Some arguments against the formal character of programming languages, Rev. Roumaine Ling.-Cahiers Ling. Theor. Appl. 13 (1976), 257-264. (in French)

  145. C. Calude, S. Marcus, I. Tevy. On recursive functions which are not recursive primitive, Rev. Roumaine Sci. Soc., Sér. Phil.-Logique 19 (1975), 185-188. (in French)

  146. C. Calude. A statistical experiment in Assembler 360, Cahiers Ling. Theor. Appl. 11 (1974), 219-230. (in French)

  147. C. Calude. On a class of distances in a free semigroup, Bull. Math. Soc. Sci. Math. R. S. Roumanie 17 (65) (1973), 133-143. (in French) (MR 51#7372, Zbl 302#68096)

  148. C. Calude. On some morphological aspects of the language Assembler 360, Cahiers Ling. Theor. Appl. 10 (1973), 153-162. (in French) (Zbl 281#68032)

Full Papers in Refereed Proceedings or Collections

  1. C. S. Calude, G. Chaitin, E. Fredkin, T. Legget, R. de Ruyter, T. Toffoli, S. Wolfram. What is computation? (How) Does nature compute? in H. Zenil (ed.). What is Computation? (How) Does Nature Compute?, World Scientific, Singapore, to appear.

  2. C. S. Calude, M. J. Dinneen, A. M. Gardner. Opening the book of randomness, in R. Copeland (ed.). DIASPAR. A Mapping of Randomness, 2010.

  3. C. S. Calude. Randomness Everywhere: My Path to Algorithmic Information Theory, in H. Zenil (ed.). Randomness Through Computation, World Scientific, Singapore, 2010, 125-133.

  4. C. S. Calude, J. Casti, G. Chaitin, P. Davies, K. Svozil, S. Wolfram. Is the universe random? in H. Zenil (ed.). Randomness Through Computation, World Scientific, Singapore, 2010, 217-251.

  5. A. A. Abbott, C. S. Calude. Von Neumann normalisation and symptoms of randomness: An application to sequences of quantum random bits, Unconventional Computation 2011, submitted.

  6. C. S. Calude, M. J. Dinneen, Monica Dumitrescu, K. Svozil. Experimental evidence of quantum randomness incomputability, in H. Guerra (ed.). Physics and Computation 2010, Pre-Proceedings, CAMIT, University of Azores, 2010, 127-145.

  7. C. S. Calude, K. Salomaa, T. K. Roblot. Finite-state complexity and the size of transducers, in I. McQuillan and G. Pighizzini (eds.). 12th International Workshop on Descriptional Complexity of Formal Systems (DCFS 2010), EPTCS 26, 2010, pp. 38-47, DOI:10.4204/EPTCS.31.6.

  8. C. S. Calude, K. Salomaa, T. K. Roblot. Finite-state complexity and randomness, in F. Ferreira, H. Guerra, E. Majordomo, J. Rasga (eds). Programs, Proofs, Processes, 6th Conference on Computability in Europe, CiE 2010, Abstract and Handbook Booklet, Ponta Delgada, Azores, Portugal, University of Azores, 2010, 73-82.

  9. A. A. Abbott, C. S. Calude. Understanding the quantum computational speed-up via de-quantisation, in S. B. Cooper, E. Kashefi, P. Panangaden (eds.). Developments in Computational Models (DCM 2010) EPTCS 26, 2010, pp. 1-12, DOI:10.4204/EPTCS.26.1.

  10. Cristian S. Calude and Christine Mueller. Formal proof: Reconciling correctness and understanding, in L. Dixon et al. (eds.) Calculemus/MKM 2009, LNAI 5625, pp. 217-232, 2009, Springer-Verlag Berlin Heidelberg.

  11. C. S. Calude. Algorithmic randomness, quantum physics, and incompleteness, in M. Margenstern (ed.). Proceedings of the Conference "Machines, Computations and Universality'' (MCU'2004), Lectures Notes in Comput. Sci. 3354, Springer, Berlin, 2005, 1--17. (invited)

  12. V. A. Adamyan, C. S. Calude, B. S. Pavlov. Transcending the limits of Turing computability, in T. Hida, K. Saito, S. Si (ed.). Quantum Information Complexity. Proceedings of Meijo Winter School 2003, World Scientific, Singapore, 2004, 119--137.

  13. C. S. Calude, S. Marcus. Mathematical proofs at a crossroad? in J. Karhumaki, H. Maurer, G. Paun, G. Rozenberg (eds.). Theory Is Forever, Lectures Notes in Comput. Sci. 3113, Springer-Verlag, Berlin, 2004, 15--28.

  14. C. S. Calude. Dialogues on quantum computing, in C. Martin-Vide, V. Mitrana and G. Paun (eds.). Formal Languages and Applications, Physica-Verlag, Heidelberg, 2004, 493--506.

  15. C. S. Calude. Who is afraid of randomness?, in E. von Collani (ed.). `Defining the Science of Stochastics', Heldermann Verlag, Sigma Series in Stochastics 1, 2004, 95--116. (Pre-proceedings: in E. von Collani (ed.). Millennial Symposium `Defining the Science of Stochastics', Wuerzburg University, 2000, 99--122) (invited)

  16. J. J. Arulanandham, C. S. Calude, M. J. Dinneen. Balance machines: Computing = balancing, in N. Jonoska, G. Paun, G. Rozenberg (eds.). Aspects of Molecular Computing, Lectures Notes in Comput. Sci. 2933, Springer-Verlag, Berlin, 2003, 36--47.

  17. C. S. Calude, L. Staiger. Generalisations of disjunctive sequences, in V. Bratka, M. Schroeder, K. Weihrauch, N. Zhong (eds.). Computability and Complexity in Analysis, Informatik Berichte 302-8 FernUniversitat in Hagen, 2003, 153--162.

  18. C. S. Calude, B. Pavlov. The Poincare--Hardy inequality on the complement of a Cantor set, in D. Alpay, I. Gohberg, V. Vinnikov (eds.). Interpolation Theory, Systems Theory and Related Topics, Operator Theory: Advances and Applications, Vol. 134, Birkhauser Verlag, Basel, 2002, 187--208.

  19. C. S. Calude, S. Marcus. Mathematical proofs at a crossroad? in J. Karhumaki, H. Maurer, G. P\u aun, G. Rozenberg (eds.). Theory Is Forever, Lectures Notes in Comput. Sci. 3113, Springer-Verlag, Berlin, 2004, 15--28.

  20. C. S. Calude. Dialogues on quantum computing, in C. Martin-Vide, V. Mitrana and G. Paun (eds.). Formal Languages and Applications, Physica-Verlag, Heidelberg, 2004, 493--506.

  21. C. S. Calude. Who is afraid of randomness?, in E. von Collani (ed.). `Defining the Science of Stochastics', Heldermann Verlag, Sigma Series in Stochastics 1, 2004, 95--116. (Pre-proceedings: in E. von Collani (ed.). Millennial Symposium `Defining the Science of Stochastics', Wuerzburg University, 2000, 99--122) (invited)

  22. J. J. Arulanandham, C. S. Calude, M. J. Dinneen. Balance machines: Computing = balancing, in N. Jonoska, G. Paun, G. Rozenberg (eds.). Aspects of Molecular Computing, Lectures Notes in Comput. Sci. 2933, Springer-Verlag, Berlin, 2003, 36--47.

  23. C. S. Calude, L. Staiger. Generalisations of disjunctive sequences, in V. Bratka, M. Schr\" oder, K. Weihrauch, N. Zhong (eds.). Computability and Complexity in Analysis, Informatik Berichte 302-8 FernUniversitat in Hagen, 2003, 153--162.

  24. C. S. Calude, B. Pavlov. The Poincare--Hardy inequality on the complement of a Cantor set, in D. Alpay, I. Gohberg, V. Vinnikov (eds.). Interpolation Theory, Systems Theory and Related Topics, Operator Theory: Advances and Applications, Vol. 134, Birkhauser Verlag, Basel, 2002, 187--208.

  25. C. S. Calude, Elena Calude. Automata: from uncertainty to quantum, in W. Kuich, G. Rozenberg, A. Salomaa (eds.) Developments in Language Theory (DLT'01), Lectures Notes in Comput. Sci. 2295, Springer-Verlag, Berlin, 2002, 1--14.

  26. C.S. Calude, K. Salomaa, S. Yu. Metric lexical analysis, in O. Boldt, H. Jürgensen (eds.) Automata Implementation, Lectures Notes in Computer Science 2214, Springer-Verlag, Heidenlberg, 2001, 48-59. Prepublication in O. Boldt, H. Jürgensen, L. Robbins (eds.) Workshop on Implementing Automata'99 (WIA'99), Preproc., 17-19 July, 1999, Potsdam, Universtität Potsdam, Institut für Informatik, Germany, 1999, VI-1-12.

  27. C.S. Calude, Elena Calude. Automata: From uncertainty to quantum, in W. Kuich, G. Rozenberg, A. Salomaa (eds.) Developments in Language Theory (DLT'01), Lectures Notes in Computer Science, Springer-Verlag, Berlin, 2001, in press. Preproceedings published by the Institute für Algebra un Computermathematik, Technische Universtät Wien, Austria, 2001, 1-16.

  28. C.S. Calude, Elena Calude, P. Kay. Liars, demons and chaos, in M. Ito, G. Paun, S. Yu (eds.). Words, Semigroups, and Transductions, World Scientific, Singapore, 2001, 33-46.

  29. C.S. Calude, Elena Calude, K. Svozil. Computational complementarity for probabilistic automata, in C. Martin-Vide, V. Mitrana (eds.). Where Mathematics, Computer Science, Linguistics and Biology Meet, Kluwer, Amsterdam, 2001, 99-113.

  30. C.S. Calude. Who is afraid of randomness ?, in E. von Collani (ed.). Millennial Symposium `Defining the Science of Stochastics', Wuerzburg University, 2000, 99-122. (invited)

  31. C.S. Calude, H. Jürgensen, S. Legg. Solving finitely refutable mathematical problems, in C. S. Calude, G. Paun (eds.). Finite Versus Infinite. Contributions to an Eternal Dilemma, Springer-Verlag, London, 2000, 39-52.

  32. C. S. Calude. A glimpse into algorithmic information theory, in L. Cavedon, P. Blackburn, N. Braisby, A. Shimojima (eds.). Logic, Language and Computation, Volume 3, CSLI Series, CSLI Lectures Notes 111, Stanford, 2000, 67-83.

  33. C.S. Calude and Elena Calude. Bisimulations and behaviour of nondeterministic automata, in G. Rozenberg, W. Thomas (eds.) Developments in Language Theory. Foundations, Applications, and Perspectives, World Scientific, Singapore, 2000, 60-70. Prepublication in W. Thomas (ed.) DLT'99, Developments in Language Theory, Fourth International Conference, Preproc., 6-9 July, 1999 Aachen, Germany, Aachener Informatik-Berichte 99-5, 129-139.

  34. C.S. Calude. A characterization of c.e. random reals, in J. Dassow, D. Wotschke (eds.) International Workshop on Descriptional Complexity of Automata, Grammars and Related Structures (DCAGRS'99), Preproc., 20-23 July, Magdeburg, Germany, 1999, 89-98.

  35. C.S. Calude, Elena Calude, K. Svozil. Quantum correlations conundrum: An automaton-theoretic approach, in C. Martin-Vide, Gh. Paun (eds.) Recent Topics in Mathematical and Computational Linguistics, The Publishing House of the Romanian Academy, Bucharest, 2000, 55-67. Prepublication in O. Boldt, H. Jürgensen, L. Robbins (eds.) Workshop on Implementing Automata'99 (WIA'99), Preproc., 17-19 July, 1999, Potsdam, Universtität Potsdam, Institut für Informatik, Germany, VII-1-12.

  36. C. S. Calude, R. J. Coles. Program-size complexity of initial segments and domination relation reducibility, in J. Karhumäki, H. A. Maurer, G. Paun, G. Rozenberg (eds.). Jewels Are Forever, Springer-Verlag, Berlin, 1999, 225-237. (invited)

  37. C. S. Calude, R. Coles, P. H. Hertling and B. Khoussainov. Degree-theoretic aspects of computably enumerable reals, in S. B. Cooper, J. K. Truss (eds.). Models and Computability, Cambridge University Press, Cambridge, 1999, 23-39.

  38. C. S. Calude, P. H. Hertling. Computable approximations of reals: An information-theoretic analysis, Extended abstract, Third International Conference on Information-Theoretic Approaches to Logic, Language, and Computation, Hsi-tou, Taiwan, The Centre for Research in Cognitive Science & Department of Psychology, National Chung Cheng University, Chiayi, 1998, 29-38.

  39. C. S. Calude, Marjo Lipponen. Computational complementarity and sofic shifts, in X. Lin (ed.). Theory of Computing 98, Proceedings of the 4th Australasian Theory Symposium, CATS'98, Springer-Verlag, Singapore, 1998, 277-290.

  40. C. S. Calude, P. Hertling, B. Khoussainov, Y. Wang. Recursively enumerable reals and Chaitin W numbers, in M. Morvan, C. Meinel, D. Krob (eds.).

    STACS'98, Proceedings of the 15th Annual Symposium on Theoretical Aspects of Computer Science, Paris, 1998, LNCS 1373, Springer-Verlag, Berlin, 1998, 596-606; full paper in Theoret. Comput. Sci. 255 (2001), 125-149.

  41. C. Calude. Computability and information, in E. Craig (ed.). Routledge Encyclopedia of Philosophy, Routledge, London, Vol. 2 (1998), 477-482. (invited)

  42. C. Calude, Elena Calude, B. Khoussainov. Deterministic automata: simulation, universality and minimality, Extended abstract, in S. Bozapalidis (ed.). Proceedings of the 3rd International Conference ``Developments in Language Theory'', Aristotel University of Thessaloniki, Thessaloniki, Greece, 1997, 519-520.

  43. C. Calude, J. Hromkovic. Complexity: A language-theoretic point of view, in G. Rozenberg, A. Salomaa (eds.). Handbook of Formal Languages, Vol. II, Springer-Verlag, Berlin, 1997, 1-60. (invited)

  44. C. Calude, H. Maurer, A. Salomaa. The Journal of Universal Computer Science and its applications to teaching, in G. Kadunz, H. Kautschitsch, G. Ossinmitz, E. Schneider (eds.). Trends und Perspectiven,\ Beiträge Zum 7. Internationalen Symposium Zur ``Didaktik der\ Mathematik'', Klagenfurt, 26-30 September 1994, Verlag Hölder-Pichler-Tempsky, Vienna, 1996, 255-261. (invited)

  45. C. Calude, S. Yu. Language-theoretic complexity of disjunctive sequences, in M. E. Houle, P. Eades (eds.), Proceedings CATS'96 (Computing: the Australian Theory Seminar), Melbourne, Australia, 29-39 January 1996, 175-179.

  46. C. Calude, M. Zimand. Effective category and measure in abstract complexity theory-extended abstract, Proceedings FCT'95, Lectures Notes in Computer Science 965, Springer-Verlag, Berlin, 1995, 156-171.

  47. C. Calude, H. Jürgensen. Randomness and coding, in M. Marinov, D. Ivanchev (eds.). 20th Summer School ``Applications of Mathematics in Engineering, Proceedings, Varna, Bulgaria, 1994, Technical University of Sofia, 1995, 53-57.

  48. C. Calude. What is a random string ?-Extended Abstract, in W. Depauli-Schimanovich, E. Koehler, F. Stadler (eds.). The Foundational Debate, Complexity and Constructivity in Mathematics and Physics, Kluwer, Dordrecht, 1995, 101-113. (invited)

  49. C. Calude, D. I. Campbell, K. Svozil, D. Stefanescu. Strong determinism vs. computability, in W. Depauli-Schimanovich, E. Koehler, F. Stadler (eds.). The Foundational Debate, Complexity and Constructivity in Mathematics and Physics, Kluwer, Dordrecht, 1995, 115-131.

  50. C. Calude, H. Maurer. Pocket mathematics, in Gh. Paun (ed.). Mathematical Aspects of Natural and Formal Languages, Scientific World, Singapore, 1994, 13-41. (invited)

  51. C. Calude, H. Jürgensen. Randomness as an invariant for number representations, in H. Maurer, J. Karhumäki, G. Rozenberg (eds.). Results and Trends in Theoretical Computer Science, Springer-Verlag, Berlin, 1994, 44-66. (Zbl 950 # 22464)  (invited)

  52. C. Calude, A. Salomaa. Algorithmically coding the universe, in G. Rozenberg, A. Salomaa (eds.). Developments in Language Theory, World Scientific, Singapore, 1994, 472-492.

  53. C. Calude. Borel normality and algorithmic randomness, in G. Rozenberg, A. Salomaa (eds.). Developments in Language Theory, World Scientific, Singapore, 1994, 113-129. (invited)

  54. C. Calude, I. Chitescu. Complexity-source of randomness, Modern Problems in Mathematical Research, Vol.1, Bucharest University, Bucharest, 1990, 165-202. Also in C. Calude (ed.). How to Cope with Complexity, Ed. Academiei, Bucharest, 1993, 34-57. (in Romanian)

  55. C. Calude. Meanings and texts: An algorithmic metaphor, in M. Balat, J. Deledalle-Rhodes (eds.). Signs of Humanity, Mouton de Gruyter, 1992, 95-97.

  56. C. Calude. On B. Russell definition of mathematics, Proc. National Symposium Info-Iasi'89, 52-59. (in Romanian) (invited)

  57. C. Calude, D. Vaida. Ehrenfeucht test set theorem and Hilbert basis theorem: a constructive glimpse, in A. Kreczmar, G. Mirkowska (eds.), Proc. Symposium Math. Found. Computer Sci. 1989, LNCS 379, Springer-Verlag, Berlin, 1989, 177-184. (MR 90m: 68009, Zbl 732#03043)

  58. C. Calude, D. Vaida. Languages, effectivity and constructive mathematics, Proc. Second National Colloquium on Languages, Logic and Mathematical Linguistics, Brasov, 1988, 47-57. (MR 90g: 03061, Zbl 667#03036)

  59. C. Calude. Romanian results in recursive function theory: 1927-1987, Proc. Computer Center Anniversary Symposium, Bucharest University, 1987, 16-22. (in Romanian) (invited)

  60. C. Calude, D. Vaida. Ehrenfeucht's property and constructivity, Proc. National Symposium Info-Iasi'87, 1-16. (in Romanian) (invited0

  61. C. Calude, I. Chitescu, L. Staiger. P. Martin-Löf tests: representability and embeddability, Proc. National Symposium Info-Iasi'85, Vol.I, 80-88. (in Romanian) (invited)

  62. C. Calude. Dilemmas of computational complexity, in C. Iacob (ed.). Mathematics, Today and Tomorrow, Ed. Academiei, Bucharest, 1985, 63-73. (in Romanian) (invited)

  63. C. Calude, I. Chitescu. On a (too) general theory of random sequences, in M. G. Demetrescu, M. Iosifescu (eds.). Studies in Probability Theory and Related Topics, Papers in Honour of Octav Onicescu on His 90th Birthday, Nagard Publisher, 1983, 65-69. (MR 85m: 0005, Zbl 562#03021) (invited)

  64. C. Calude. On a class of independent problems related to Rice's theorem, Proc. National Symposium Info-Iasi'83, 29-32. (in Romanian)

  65. C. Calude, Gh. Paun. On the adequacy of a grammatical model of the brain, in M. Draganescu (ed.). Artificial Intelligence and Robotics, Ed. Academiei, Bucharest, 1983, 45-50. (in Romanian)

  66. C. Calude, Gh. Paun. The absence of contextual ambiguities in the programming languages Fortran and Assiris, in S. Marcus(ed.). Contextual Ambiguities in Natural and Artificial Languages, Vol. 2, Ghent, Belgium, 1983, 57-76.

  67. C. Calude, S. Marcus, Gh. Paun. Empirical Information and Theoretical Constructs in the Study of Needs II, in S. Marcus (ed.). Mathematical Methods in the Development Problematique, Ed. Academiei, Bucharest, 1982, 39-59. (in Romanian) (MR 83k: 92005)

  68. C. Calude, I. Chitescu. On Per Martin-Löf random sequences, Proc. National Symposium Info-Iasi'81, 1-5. (in Romanian)

  69. C. Calude, V. Vieru. Knuth test on compiler efficiency, Proc. 4th International Conference on Control Systems and Computer Science, Bucharest, Politechnical Institute, Vol. IV, 1981, 113-115.

  70. C. Calude, Gh. Paun. An argument for the formal character of the programming language Fortran, in P. Miclau, S. Marcus (eds.). Sémiotique Roumaine, Bucharest University, 1981, 61-72.

  71. C. Calude, Mihaela Malita, On the category of Cech topological spaces, in A. Czaszar(ed.). Topology, Vol. I, North-Holland, Amsterdam, l980, 225-232. (MR 82e: 54012, Zbl 444#54001)

  72. C. Calude, S. Marcus, Gh. Paun. The universal grammar as a hypothetical brain, Proc. Intern. Symposium on Mathematics in System Theory, Brasov, 1978, 93-114. (Zbl 457#68093)

  73. C. Calude, C. S. Calude. Mathematical modeling and systemic approach in juridical sciences, in M. Malita (ed.). Systems in Social Sciences, Ed. Academiei, Bucharest, 1977, 105-109. (in Romanian)

  74. C. Calude. Pompeiu's distance between closed sets, Symposium on Geometry and Global Analysis, Bucharest, 1973, Ed. Academiei, Bucharest, 281-288. (in Romanian) (MR 58#10123, Zbl 397#54015)

  75. C. Calude. Semiotic analysis of a morphological experiment in a programming language, in S. Chatman, U. Eco, J. M. Klinkenberg (eds.). Approaches to Semiotics, Proc. of the First Congress IAS, 1973, Mouton, The Hague, 1979, 433-436. (in French)