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Synchronization Problems in Automata Without Non-trivial Cycles

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Implementation and Application of Automata (CIAA 2017)

Part of the book series: Lecture Notes in Computer Science ((LNTCS,volume 10329))

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Abstract

We study the computational complexity of various problems related to synchronization of weakly acyclic automata, a subclass of widely studied aperiodic automata. We provide upper and lower bounds on the length of a shortest word synchronizing a weakly acyclic automaton or, more generally, a subset of its states, and show that the problem of approximating this length is hard. We also show inapproximability of the problem of computing the rank of a subset of states in a binary weakly acyclic automaton and prove that several problems related to recognizing a synchronizing subset of states in such automata are NP-complete.

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References

  1. Ananichev, D., Volkov, M.: Synchronizing monotonic automata. Theor. Comput. Sci. 327(3), 225–239 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  2. Berlinkov, M.V.: On two algorithmic problems about synchronizing automata. In: Shur, A.M., Volkov, M.V. (eds.) DLT 2014. LNCS, vol. 8633, pp. 61–67. Springer, Cham (2014). doi:10.1007/978-3-319-09698-8_6

    Google Scholar 

  3. Bondar, E.A., Volkov, M.V.: Completely reachable automata. In: Câmpeanu, C., Manea, F., Shallit, J. (eds.) DCFS 2016. LNCS, vol. 9777, pp. 1–17. Springer, Cham (2016). doi:10.1007/978-3-319-41114-9_1

    Chapter  Google Scholar 

  4. Brzozowski, J., Fich, F.E.: Languages of R-trivial monoids. J. Comput. Syst. Sci. 20(1), 32–49 (1980)

    Article  MathSciNet  MATH  Google Scholar 

  5. Cardoso, A.: The Černý Conjecture and Other Synchronization Problems. Ph.D. thesis. University of Porto, Portugal (2014)

    Google Scholar 

  6. Cormen, T.H., Leiserson, C.E., Rivest, R.L., Stein, C.: Introduction to Algorithms, 3rd edn. MIT Press (2009)

    Google Scholar 

  7. Eppstein, D.: Reset sequences for monotonic automata. SIAM J. Comput. 19(3), 500–510 (1990)

    Article  MathSciNet  MATH  Google Scholar 

  8. Gawrychowski, P., Straszak, D.: Strong inapproximability of the shortest reset word. In: Italiano, G.F., Pighizzini, G., Sannella, D.T. (eds.) MFCS 2015. LNCS, vol. 9234, pp. 243–255. Springer, Heidelberg (2015). doi:10.1007/978-3-662-48057-1_19

    Chapter  Google Scholar 

  9. Gerencsér, B., Gusev, V.V., Jungers, R.M.: Primitive sets of nonnegative matrices and synchronizing automata. CoRR abs/1602.07556 (2016)

    Google Scholar 

  10. Jirásková, G., Masopust, T.: On the state and computational complexity of the reverse of acyclic minimal dfas. In: Moreira, N., Reis, R. (eds.) CIAA 2012. LNCS, vol. 7381, pp. 229–239. Springer, Heidelberg (2012). doi:10.1007/978-3-642-31606-7_20

    Chapter  Google Scholar 

  11. Kozen, D.: Lower bounds for natural proof systems. In: Proceedings of the 18th Annual Symposium on Foundations of Computer Science, pp. 254–266 (1977)

    Google Scholar 

  12. Martyugin, P.V.: Complexity of problems concerning carefully synchronizing words for PFA and directing words for NFA. In: Ablayev, F., Mayr, E.W. (eds.) CSR 2010. LNCS, vol. 6072, pp. 288–302. Springer, Heidelberg (2010). doi:10.1007/978-3-642-13182-0_27

    Chapter  Google Scholar 

  13. Mycielski, J.: Sur le coloriage des graphs. Colloquium Mathematicae 3(2), 161–162 (1955)

    MathSciNet  MATH  Google Scholar 

  14. Natarajan, B.K.: An algorithmic approach to the automated design of parts orienters. In: Proceedings of the 27th Annual Symposium on Foundations of Computer Science, pp. 132–142 (1986)

    Google Scholar 

  15. Pin, J.É.: On two combinatorial problems arising from automata theory. Ann. Discrete Math. 17, 535–548 (1983)

    MathSciNet  MATH  Google Scholar 

  16. Rystsov, I.K.: Rank of a finite automaton. Cybern. Syst. Anal. 28(3), 323–328 (1992)

    Article  MathSciNet  MATH  Google Scholar 

  17. Rystsov, I.K.: Polynomial complete problems in automata theory. Inform. Process. Lett. 16(3), 147–151 (1983)

    Article  MathSciNet  MATH  Google Scholar 

  18. Rystsov, I.K.: Reset words for commutative and solvable automata. Theor. Comput. Sci. 172(1), 273–279 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  19. Ryzhikov, A.: Approximating the maximum number of synchronizing states in automata. CoRR abs/1608.00889 (2016)

    Google Scholar 

  20. Sandberg, S.: Homing and synchronizing sequences. In: Broy, M., Jonsson, B., Katoen, J.-P., Leucker, M., Pretschner, A. (eds.) Model-Based Testing of Reactive Systems. LNCS, vol. 3472, pp. 5–33. Springer, Heidelberg (2005). doi:10.1007/11498490_2

    Chapter  Google Scholar 

  21. Sipser, M.: Introduction to the Theory of Computation. Cengage Learning, 3rd edn. (2012)

    Google Scholar 

  22. Szykuła, M.: Improving the upper bound the length of the shortest reset words. CoRR abs/1702.05455 (2017)

    Google Scholar 

  23. Trahtman, A.N.: The Cerný conjecture for aperiodic automata. Discrete Math. Theor. Comput. Sci. 9(2), 3–10 (2007)

    MathSciNet  MATH  Google Scholar 

  24. Vazirani, V.V.: Approximation Algorithms. Springer, Heidelberg (2001)

    Google Scholar 

  25. Volkov, M.V.: Synchronizing automata and the Černý conjecture. In: Martín-Vide, C., Otto, F., Fernau, H. (eds.) LATA 2008. LNCS, vol. 5196, pp. 11–27. Springer, Heidelberg (2008). doi:10.1007/978-3-540-88282-4_4

    Chapter  Google Scholar 

  26. Vorel, V.: Subset synchronization and careful synchronization of binary finite automata. Int. J. Found. Comput. Sci. 27(5), 557–578 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  27. Zuckerman, D.: Linear degree extractors and the inapproximability of max clique and chromatic number. Theory Comput. 3(6), 103–128 (2007)

    Article  MathSciNet  MATH  Google Scholar 

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Acknowledgments

We would like to thank Vladimir Gusev and Ilia Fridman for very useful discussions, and Mikhail V. Volkov and anonymous reviewers for their great contribution to the improvement of the paper.

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Ryzhikov, A. (2017). Synchronization Problems in Automata Without Non-trivial Cycles. In: Carayol, A., Nicaud, C. (eds) Implementation and Application of Automata. CIAA 2017. Lecture Notes in Computer Science(), vol 10329. Springer, Cham. https://doi.org/10.1007/978-3-319-60134-2_16

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  • DOI: https://doi.org/10.1007/978-3-319-60134-2_16

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