Tsunehiro Yoshinaga

  • Citations Per Year
Learn More
We consider the Turing machine model with a two-way, read-only input tape and a separate two-way, read-write worktape [3]. The 1-inkdot Turing machine introduced by Ranjan et al. [7] is a Turing machine with the additional power of marking at most 1 tape-cell on the input (with an inkdot) once. The action of the machine depends on the current state, the(More)
This paper investigates in3nite hierarchies on alternation-depth and alternation-size of alternating pushdown automata (apda’s) with sublogarithmic space. We 3rst show that there is an in3nite hierarchy on alternation-depth for apda’s with sublogarithmic space. We next investigate a relationship between alternation-depth and alternation-size, and show that(More)
M. Blum and C. Hewitt first proposed two-dimensional automata as a computational model of two-dimensional pattern processing in 1967, and investigated their pattern recognition abilities. Since then, many researchers in this field have investigated many properties of automata on a two- or three-dimensional tape. However, the question of whether processing(More)
1-inkdot alternating pushdown automaton is a slightly modified alternating pushdown automaton with the additional power of marking at most 1 tape-cell on the input (with an inkdot) once. This paper investigates the closure property of sublogarithmic space-bounded 1-inkdot alternating pushdown automata with only existential (universal) states, and shows, for(More)
This paper presents a four-dimensional computational model, k-neighborhood template A-type three-dimensional bounded cellular acceptor (abbreviated as A-3BCA(k)), and discusses the hierarchical properties. An A-3BCA(k) is a four-dimensional automaton which consists of a pair of a converter and a configuration-reader. The former converts the given(More)