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Parallel computation using active self-assembly

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Abstract

We study the computational complexity of the recently proposed nubots model of molecular-scale self-assembly. The model generalises asynchronous cellular automata to have non-local movement where large assemblies of molecules can be moved around, analogous to millions of molecular motors in animal muscle effecting the rapid movement of macroscale arms and legs. We show that nubots is capable of simulating Boolean circuits of polylogarithmic depth and polynomial size, in only polylogarithmic expected time. In computational complexity terms, we show that any problem from the complexity class NC is solved in polylogarithmic expected time on nubots that use a polynomial amount of workspace. Along the way, we give fast parallel algorithms for a number of problems including line growth, sorting, Boolean matrix multiplication and space-bounded Turing machine simulation, all using a constant number of nubot states (monomer types). Circuit depth is a well-studied notion of parallel time, and our result implies that nubots is a highly parallel model of computation in a formal sense. Asynchronous cellular automata are not capable of such parallelism, and our result shows that adding a movement primitive to such a model, to get the nubots model, drastically increases parallel processing abilities.

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Notes

  1. \({\mathrm{NC}}\), or Nick’s class, is named after Nicholas Pippenger.

  2. By confluent we mean a kind of determinism where the system (rules with the input) is assumed to always make a unique single terminal assembly.

  3. In Woods et al. (2013) the nubots model includes “agitation”: each monomer is repeatedly subjected to random movements intended to model a nano-scale environment where there is Brownian motion, uncontrolled movements and turbulent fluid flows in all directions. Our constructions in this paper work with or without agitation, hence they are robust to random uncontrolled movements, but we choose to ignore this issue and not formally define agitation for ease of presentation.

  4. For simplicity, when counting the number of applicable rules for a configuration, a movement rule is counted twice, to account for the two choices of arm and base.

  5. Our choice of a 1D, rather than 2D, encoding simplifies our constructions. It would also be possible use a more direct 2D square encoding, which, it turns out, can be unfolded to and from our line encoding in expected time \(O(\log n)\). We omit the details.

  6. Our configurations include an output tape write symbol and an output tape head position which is not standard practice (Papadimitriou 1994), but will be useful in our construction.

  7. Each configuration is of length polynomial in \(|x| = O(|\) \([\widetilde{x}]\) \(|)\), hence including \([\widetilde{x}]\) here does not change the asymptotics.

  8. The line segments in an encoded matrix usually encode the matrix element’s \((i, j)\) coordinates, here we do things slightly differently: we are using encoded configurations, rather than natural numbers, as the matrix indices. This simplifies our constructions a little.

References

  • Aggarwal G, Cheng Q, Goldwasser MH, Kao M-Y, de Espanes PM, Schweller RT (2005) Complexities for generalized models of self-assembly. SIAM J Comput 34:1493–1515

    Article  MATH  MathSciNet  Google Scholar 

  • Allender E, Koucký M (2010) Amplifying lower bounds by means of self-reducibility. JACM 14:1–36

    Article  Google Scholar 

  • Aloupis G, Collette S, Demaine ED, Langerman S, Sacristán V, Wuhrer S (2008) Reconfiguration of cube-style modular robots using \(O(\log n)\) parallel moves. In: ISAAC: Proc. of the 19th Annual International Symposium on Algorithms and Computation, pp 342–353

  • Aloupis G, Collette S, Damian M, Demaine E, Flatland R, Langerman S, O’Rourke J, Pinciu V, Ramaswami S, Sacristán V, Wuhrer S (2011) Efficient constant-velocity reconfiguration of crystalline robots. Robotica 29(1):59–71

    Article  Google Scholar 

  • Becker F, Remila E, Rapaport I (2006) Self-assemblying classes of shapes, fast and with minimal number of tiles. In: Proceedings of the 26th Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2006), vol 4337 of LNCS. Springer, pp 45–56

  • Butler Z, Fitch R, Rus D (2002) Distributed control for unit-compressible robots: goal-recognition, locomotion, and splitting. IEEE/ASME Trans Mechatron 7:418–430

    Article  Google Scholar 

  • Cannon S, Demaine ED, Demaine ML, Eisenstat S, Patitz MJ, Schweller RT, Summers SM, Winslow A (2013) Two hands are better than one (up to constant factors): Self-assembly In the 2HAM vs. aTAM. In: STACS: 30th International Symposium on Theoretical Aspects of Computer, Science, pp 172–184

  • Chandran H, Gopalkrishnan N, Reif J (2012) Tile complexity of approximate squares. Algorithmica 66(1):1–17

    Article  MathSciNet  Google Scholar 

  • Condon A (1994) A theory of strict P-completeness. Comput Complex 4(3):220–241

    Article  MATH  MathSciNet  Google Scholar 

  • Dabby N, Chen H-L (2012) Active self-assembly of simple units using an insertion primitive. In: SODA: Proceedings of the 24th Annual ACM-SIAM Symposium on Discrete Algorithms, pp 1526–1536

  • Demaine E, Demaine M, Fekete S, Ishaque M, Rafalin E, Schweller R, Souvaine D (2008) Staged self-assembly: nanomanufacture of arbitrary shapes with \({O}(1)\) glues. Nat Comput 7(3):347–370

    Article  MATH  MathSciNet  Google Scholar 

  • Demaine ED, Eisenstat S, Ishaque M, Winslow A (2011) One-dimensional staged self-assembly. In: DNA: 17th Intl Conf on DNA Computing & Molecular Programming, vol 6937 of LNCS. Pasadena, pp 100–114

  • Demaine ED, Patitz MJ, Rogers TA, Schweller RT, Summers SM, Woods D (2013) The two-handed tile assembly model is not intrinsically universal. In: ICALP: 40th International Colloquium on Automata, Languages and Programming. Proceedings, part 1, vol 7965 of LNCS. Riga, Latvia, pp 400–412. arXiv:1306.6710 [cs.CG]

  • Demaine ED, Demaine ML, Fekete SP, Patitz MJ, Schweller RT, Winslow A, Woods D (2014) One tile to rule them all: simulating any Turing machine, tile assembly system, or tiling system with a single puzzle piece. In: ICALP: Proceedings of the 41st International Colloquium on Automata, Languages, and Programming. arXiv:1212.4756 [cs.DS]

  • Doty D (2010) Randomized self-assembly for exact shapes. SICOMP 39:3521

    Article  MATH  MathSciNet  Google Scholar 

  • Doty D, Lutz JH, Patitz MJ, Summers SM, Woods D (2009) Intrinsic universality in self-assembly. In: STACS: Proceedings of the 27th International Symposium on Theoretical Aspects of Computer, Science, pp 275–286

  • Doty D, Lutz JH, Patitz MJ, Schweller RT, Summers SM, Woods D (2012) The tile assembly model is intrinsically universal. In: FOCS: Proceedings of the 53rd Annual IEEE Symposium on Foundations of Computer, Science, pp 439–446

  • Fu B, Patitz M, Schweller R, Sheline B (2012) Self-assembly with geometric tiles. In: ICALP: The 39th International Colloquium on Automata, Languages and Programming, vol 7391 of LNCS. Springer, pp 714–725

  • Gillespie D (1992) A rigorous derivation of the chemical master equation. Phys A 188(1):404–425

    Article  MathSciNet  Google Scholar 

  • Greenlaw R, Hoover HJ, Ruzzo WL (1995) Limits to parallel computation: P-completeness theory. Oxford University Press, USA

    MATH  Google Scholar 

  • Hendricks J, Patitz MJ (2013) On the equivalence of cellular automata and the tile assembly model. In: MCU: Proceedings of Machines, Computations and Universality. University of Zürich, Switzerland. September 9–12, Electronic Proceedings in Theoretical Computer Science, vol 128, pp 167–189

  • Hendricks J, Padilla JE, Patitz MJ, Rogers TA (2013) Signal transmission across tile assemblies: 3D static tiles simulate active self-assembly by 2D signal-passing tiles. In: DNA19: The 19th International Conference on DNA Computing and Molecular Programming, vol 8141 of LNCS. Springer. arXiv:1306.5005 [cs.ET]

  • Jonoska N, McColm GL (2009) Complexity classes for self-assembling flexible tiles. Theoret Comput Sci 410(4):332–346

    Article  MATH  MathSciNet  Google Scholar 

  • Jonoska N, Karpenko D (2012) Active tile self-assembly, self-similar structures and recursion. arXiv:1211.3085 [cs.ET]

  • Kao M., Schweller R. (2006) Reducing tile complexity for self-assembly through temperature programming. In: SODA: Proceedings of the Seventeenth Annual ACM-SIAM Symposium on Discrete Algorithms, ACM, pp 571–580

  • Kao M, Schweller R (2008) Randomized self-assembly for approximate shapes. In ICALP: Proceedings of the 35th International Colloquium on Automata, Languages and Programming, vol 5125 of LNCS. Springer, pp 370–384

  • Keenan A, Schweller R, Sherman M, Zhong X (2014) Fast arithmetic in algorithmic self-assembly. In: UCNC : the 13th International Conference on Unconventional Computation and Natural Computation. arXiv:1303.2416 [cs.DS]

  • Klavins E (2004) Directed self-assembly using graph grammars. Self Assembled Architectures and Devices, Snowbird, UT, In Foundations of Nanoscience

  • Malchik C, Winslow A (2014) Tight bounds for active self-assembly using an insertion primitive. The 22nd European Symposium on Algorithms. arXiv:1401.0359 [cs.FL]

  • Martin AC, Kaschube M, Wieschaus EF (2008) Pulsed contractions of an actin-myosin network drive apical constriction. Nature 457(7228):495–499

    Article  Google Scholar 

  • Meunier P-E, Patitz MJ, Summers SM, Theyssier G, Winslow A, Woods D (2014) Intrinsic universality in tile self-assembly requires cooperation. In: SODA: ACM-SIAM Symposium on Discrete Algorithms, pp 752–771. arXiv:1304.1679 [cs.CC]

  • Murata S, Kurokawa H (2007) Self-reconfigurable robots. IEEE Robot Autom Mag 14(1):71–78

    Article  Google Scholar 

  • Murphy N, Woods D (2013) AND and/or OR: uniform polynomial-size circuits. In MCU: Machines, Computations and Universality, vol 128, pp 150–166, EPTCS. arXiv:1212.3282

  • Murphy N, Naughton TJ, Woods D, Henley B, McDermott K, Duffy E, van der Burgt PJ, Woods N (2008) Implementations of a model of physical sorting. Int J Unconv Comput 4(1):3–12

    Google Scholar 

  • Neary T, Woods D (2006) P-completeness of cellular automaton rule 110. In: ICALP: The 33rd International Colloquium on Automata, Languages and Programming, vol 4051 of LNCS. Springer, pp 132–143

  • Padilla J, Liu W, Seeman N (2011) Hierarchical self assembly of patterns from the Robinson tilings: DNA tile design in an enhanced tile assembly model. Nat Comput 11(2):323–338

    Article  MathSciNet  Google Scholar 

  • Padilla J, Patitz M, Pena R, Schweller R, Seeman N, Sheline R, Summers S, Zhong X (2013) Asynchronous signal passing for tile self-assembly: fuel efficient computation and efficient assembly of shapes. In Unconventional Computation and Natural Computation, vol 7956 of LNCS. Springer, pp 174–185

  • Papadimitriou CM (1994) Computational complexity. Addison-Wesley, New York

    MATH  Google Scholar 

  • Patitz MJ (2012) An introduction to tile-based self-assembly. In: Unconventional Computation and Natural Computation, vol 7445 LNCS. Springer, pp 34–62

  • Prusinkiewicz P, Lindenmayer A (1990) The algorithmic beauty of plants. Springer, New York

    Book  MATH  Google Scholar 

  • Reif J, Slee S (2007) Optimal kinodynamic motion planning for 2D reconfiguration of self-reconfigurable robots. Robot Sci Syst 12(2):81–115

    Google Scholar 

  • Rothemund PWK, Winfree E (2000) The program-size complexity of self-assembled squares (extended abstract). In: STOC: Proceedings of the thirty-second annual ACM symposium on Theory of computing. ACM Press, pp 459–468

  • Rus D, Vona M (2001) Crystalline robots: self-reconfiguration with compressible unit modules. Auton Robots 10(1):107–124

    Article  MATH  Google Scholar 

  • Schultes D (2006) Rainbow sort: sorting at the speed of light. Nat Comput 5(1):67–82

    Article  MATH  MathSciNet  Google Scholar 

  • Soloveichik D, Cook M, Winfree E, Bruck J (2008) Computation with finite stochastic chemical reaction networks. Nat Comput 7(4):615–633

    Article  MATH  MathSciNet  Google Scholar 

  • Summers S (2012) Reducing tile complexity for the self-assembly of scaled shapes through temperature programming. Algorithmica 4:1–20

    Google Scholar 

  • Vollmer H (1999) Introduction to circuit complexity: a uniform approach. Springer, New York

    Book  Google Scholar 

  • Winfree E (1988) Algorithmic Self-assembly of DNA. Ph.D. thesis, California Institute of Technology

  • Woods D (2005) Upper bounds on the computational power of an optical model of computation. In: Algorithms and Computation. Springer, pp 777–788

  • Woods D (2013) Intrinsic universality and the computational power of self-assembly. In: MCU: Proceedings of Machines, Computations and Universality, vol 128. Univ. of Zürich, Switzerland. Sept 9–12, Electronic Proceedings in Theoretical Computer Science, pp 16–22

  • Woods D, Naughton TJ (2008) Parallel and sequential optical computing. In: Optical supercomputing, vol 5172 of LNCS. Springer, pp 70–86

  • Woods D, Chen H-L, Goodfriend S, Dabby N, Winfree E, Yin P (2013) Active self-assembly of algorithmic shapes and patterns in polylogarithmic time. In: ITCS’13: Proceedings of the 4th conference on Innovations in Theoretical Computer Science. ACM, pp 353–354. Full version: arXiv:1301.2626 [cs.DS]

  • Yurke B, Turberfield AJ, Mills AP Jr, Simmel FC, Nuemann JL (2000) A DNA-fuelled molecular machine made of DNA. Nature 406:605–608

    Article  Google Scholar 

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Acknowledgments

We thank Erik Winfree for valuable discussion and suggestions on our results, Paul Rothemund for stimulating conversations on molecular muscle, Niall Murphy for informative discussions on circuit complexity theory, and Dhiraj Holden and Dave Doty for useful discussions. Damien thanks Beverley Henley for introducing him to developmental biology many moons ago. Supported by National Science Foundation grants CCF-1219274, 0832824 (The Molecular Programming Project), and CCF-1162589.

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Correspondence to Damien Woods.

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Preliminary version appeared at The 19th International Conference on DNA Computing and Molecular Programming (DNA 19).

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Chen, M., Xin, D. & Woods, D. Parallel computation using active self-assembly. Nat Comput 14, 225–250 (2015). https://doi.org/10.1007/s11047-014-9432-y

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