Journal Papers

  1. Generalized predecessor existence problems for Boolean finite dynamical systems on directed graphs,
    Akinori Kawachi, Mitsunori Ogihara, Kei Uchizawa
    Theoretical Computer Science, Vol. 762, pp. 25-40, Mar. 2019. [LINK]
  2. Computational power of threshold circuits of energy at most two,
    Hiroki Maniwa, Takayuki Oki, Akira Suzuki, Kei Uchizawa, Xiao Zhou
    IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Vol.E101-A No.9 pp.1431-1439, Sep. 2019. [LINK]
  3. Computational complexity studies of synchronous Boolean finite dynamical systems on directed graphs,
    Mitsunori Ogihara, Kei Uchizawa,
    Information and Computation, Vol. 256, pp. 225-236, Oct. 2017. [LINK]
  4. Hitori numbers,
    Akira Suzuki, Masashi Kiyomi, Yota Otachi, Kei Uchizawa, Takeaki Uno,
    Journal of Information Processing, Vol. 25, pp. 695-707, Aug. 2017. [LINK]
  5. Threshold circuits detecting global patterns in two-dimensional maps,
    Kei Uchizawa, Daiki Yashima and Xiao Zhou,
    Journal of Graph Algorithms and Applications, Vol. 20, pp. 115-131, Feb. 2016. [LINK]
  6. Swapping labeled tokens on graphs,
    Katsuhisa Yamanaka, Erik D. Demaine, Takehiro Ito, Jun Kawahara, Masashi Kiyomi, Yoshio Okamoto, Toshiki Saitoh, Akira Suzuki, Kei Uchizawa, Takeaki Uno,
    Theoretical Computer Science, Vol. 586, pp. 81-94, Jun. 2015. [LINK]
  7. Generalized rainbow connectivity of graphs,
    Kei Uchizawa, Takanori Aoki, Takehiro Ito, Xiao Zhou,
    Theoretical Computer Science, Vol. 555, pp. 35-42, Oct. 2014. [LINK]
  8. Lower bounds for threshold circuits of bounded energy,
    Kei Uchizawa,
    Interdisciplinary Information Sciences, Vol. 20(1), pp. 27-50, Mar. 2014. [LINK]
  9. On the rainbow connectivity of graphs: complexity and FPT algorithms,
    Kei Uchizawa, Takanori Aoki, Takehiro Ito, Akira Suzuki, Xiao Zhou,
    Algorithmica, Vol. 67(2), pp. 161-179, Sep. 2013. [LINK]
  10. Energy and fan-in of logic circuits computing symmetric Boolean functions,
    Akira Suzuki, Kei Uchizawa, Xiao Zhou,
    Theoretical Computer Science, Vol. 505, pp. 74-80, Sep. 2013. [LINK]
  11. Energy-efficient threshold circuits computing MOD functions,
    Akira Suzuki, Kei Uchizawa, Xiao Zhou,
    International Journal of Foundations of Computer Science, Vol. 24(1), pp. 15-29, Jan. 2013. [LINK]
  12. Energy-efficient threshold circuits for comparison functions,
    Kei Uchizawa, Xiao Zhou,
    Interdisciplinary Information Sciences, Vol. 18(2), pp. 161-166, Dec. 2012. [LINK]
  13. Size-energy tradeoffs for unate circuits computing symmetric Boolean functions,
    Kei Uchizawa, Eiji Takimoto, Takao Nishizeki,
    Theoretical Computer Science, Vol. 412(8-10), pp. 773-782, Mar. 2011. [LINK]
  14. Energy and depth of threshold circuits,
    Kei Uchizawa, Takao Nishizeki, Eiji Takimoto,
    Theoretical Computer Science, Vol. 411(44-46), pp. 3938-3946, Oct. 2010. [LINK]
  15. Exponential lower bounds on the size of constant-depth threshold circuits with small energy complexity,
    Kei Uchizawa, Eiji Takimoto,
    Theoretical Computer Science, Vol. 407(1-3), pp. 474-487, Nov. 2008. [LINK]
  16. On the computational power of threshold circuits with sparse activity,
    Kei Uchizawa, Rodney J. Douglas, Wolfgang Maass,
    Neural Computation, Vol. 18(12), pp. 2994-3008, Dec. 2008. [LINK]

Refereed Conference Papers

  1. Generalized Predecessor Existence Problems for Boolean Finite Dynamical Systems,
    Akinori Kawachi, Mitsunori Ogihara , Kei Uchizawa,
    Proc. of the 42nd International Symposium on Mathematical Foundations of Computer Science (MFCS 2017), to appear.
  2. Competitive Diffusion on Weighted Graphs,
    Takehiro Ito, Yota Otachi, Toshiki Saitoh, Hisayuki Satoh, Akira Suzuki, Kei Uchizawa, Ryuhei Uehara, Katsuhisa Yamanaka, Xiao Zhou,
    Proc. of the 14th International Symposium on Algorithms and Data Structures (WADS 2015), Lecture Notes in Computer Science (LNCS), Vol. 9214, pp. 422-433, 2015. [LINK]
  3. Computational Complexity Studies of Synchronous Boolean Finite Dynamical Systems,
    Mitsunori Ogihara, Kei Uchizawa,
    Proc. of the 12th Annual Conference on Theory and Applications of Models of Computation (TAMC 2015), Lecture Notes in Computer Science (LNCS), Vol. 9076, pp. 87-98, 2015. [LINK]
  4. Threshold Circuits for Global Patterns in 2-Dimensional Maps,
    Kei Uchizawa, Daiki Yashima and Xiao Zhou,
    Proc. of the 9th International Workshop on Algorithms and Computation (WALCOM 2015), Lecture Notes in Computer Science (LNCS), Vol. 8973, pp. 306-316, 2015. [LINK]
  5. Lower Bounds for Linear Decision Trees with Bounded Weights,
    Kei Uchizawa, Eiji Takimoto,
    Proc. of the 41st International Conference on Current Trends in Theory and Practice of
    Computer Science (SOFSEM 2015), Lecture Notes in Computer Science (LNCS), Vol. 8939, pp. 412-422, 2015. [LINK]
  6. Swapping Labeled Tokens on Graphs,
    Katsuhisa Yamanaka, Erik D. Demaine, Takehiro Ito, Jun Kawahara, Masashi Kiyomi, Yoshio Okamoto, Toshiki Saitoh, Akira Suzuki, Kei Uchizawa, Takeaki Uno,
    Proc. of the 7th International Conference on FUN with Algorithms (FUN 2014), Lecture Notes in Computer Science (LNCS), Vol. 8496, pp. 364-375, 2014. [LINK]
  7. Energy-Efficient Threshold Circuits Detecting Global Pattern in 1-Dimensional Arrays,
    Akira Suzuki, Kei Uchizawa, Xiao Zhou,
    Proc. of of the 10th annual conference on Theory and Applications of Models of Computation (TAMC 2013), Lecture Notes in Computer Science (LNCS), Vol. 7876, pp. 248-259, 2013. [LINK]
  8. Generalized Rainbow Connectivity of Graphs,
    Kei Uchizawa, Takanori Aoki, Takehiro Ito,
    Proc. of the 7th International Workshop on Algorithms and Computation (WALCOM 2013), Lecture Notes in Computer Science (LNCS), Vol. 7936, pp. 729-736, 2013. [LINK]
  9. Complexity of Counting Output Patterns of Logic Circuits,
    Kei Uchizawa, Zhenghong Wang, Hiroki Morizumi, Xiao Zhou,
    Proc. of the 19th Computing: the Australasian Theory Symposium (CATS 2013), Conferences in Research and Practice in Information Technology (CRIPT), Vol. 141, pp. 37-43, 2013. [LINK]
  10. Hitori Number,
    Akira Suzuki, Kei Uchizawa, Takeaki Uno,
    Proc. of the 6th International Conference on Fun with Algorithms (FUN 2012), Lecture Notes in Computer Science (LNCS), Vol. 7288, pp. 334-345, 2012. [LINK]
  11. Lower Bounds for Linear Decision Trees via an Energy Complexity Argument,
    Kei Uchizawaa, Eiji Takimoto,
    Proc. of the 36th International Symposiums on Mathematical Foundations of Computer Science (MFCS 2011), Lecture Notes in Computer Science (LNCS), Vol. 6907, pp. 568-579, 2011. [LINK]
  12. On the Rainbow Connectivity of Graphs: Complexity and FPT Algorithms,
    Kei Uchizawa, Takanori Aoki, Takehiro Ito, Akira Suzuki and Xiao Zhou,
    Proc. of the 17th Annual International Computing and Combinatorics Conference (COCOON 2011), Lecture Notes in Computer Science (LNCS), Vol. 6842, pp. 86-97, 2011. [LINK]
  13. Energy and Fan-in of Threshold Circuits Computing Mod Functions,
    Akira Suzuki, Kei Uchizawa, Takeaki Uno,
    Proc. of he 8th Annual Conference on Theory and Applications of Models of Computation (TAMC 2011), Lecture Notes in Computer Science (LNCS), Vol. 6648, pp. 154-163, 2011. [LINK]
  14. Energy-Efficient Threshold Circuits Computing Mod Functions,
    Akira Suzuki, Kei Uchizawa, Xiao Zhou,
    Proc. of the 17th Computing: the Australasian Theory Symposium (CATS 2011), Conferences in Research and Practice in Information Technology (CRPIT), Vol. 119, pp. 105-110, 2011. [LINK]
  15. Energy Complexity and Depth of Threshold Circuits,
    Kei Uchizawa, Eiji Takimoto, Takao Nishizeki,
    Proc. of the 17th International Symposium on Fundamentals of Computation Theory (FCT 2009), Lecture Notes in Computer Science (LNCS), Vol.5699, pp. 335-345, 2009. [LINK]
  16. Size and Energy of Threshold Circuits Computing Mod Functions,
    Kei Uchizawa, Takao Nishizeki, Eiji Takimoto,
    Proc. of the 34th International Symposiums on Mathematical Foundations of Computer Science (MFCS 2009), Lecture Notes in Computer Science (LNCS), Vol. 5734, pp. 724-735, 2009. [LINK]
  17. An Exponential Lower Bound on the Size of Constant-Depth Threshold Circuits with Small Energy Complexity,
    Kei Uchizawa, Eiji Takimoto,
    Proc. of the 22nd IEEE Conference on Computational Complexity (CCC 2007), pp. 169-178, 2007. [LINK]
  18. Energy Complexity and Entropy of Threshold Circuits,
    Kei Uchizawa, Rodney Douglas, Wolfgang Maass,
    Proc. of the 33rd International Colloquium on Automata, Languages and Programming (ICALP 2006), Lecture Notes in Computer Science (LNCS), Vol. 4051, pp. 631-642, 2006. [LINK]