Yasuaki Nishitani

Learn More
tn this paper, we give a solution of the Firing Squad Synchronization Problem for graphs. The synchronization *imes of solutions which have been obtained are proportional to the number or nodes of a graph. T~e synchronization time of our solution is proport[onal to the radius rG of a graph G (3re; + 1 or 3rG time units), where rG is the longest distance(More)
As classes of AND-EXOR expressions, PPRMs, FPRMs, and ESOPs are well-known. In this paper, a new class of AND-EXOR expressions, Double Fixed-Polarity Reed-Muller Expressions (DFPRMs), is proposed. DFPRMs are generalized expressions of FPRMs, and can be the smallest PLA among all the classes of AND-EXOR expressions. We discuss their properties: the relation(More)
Concurrent expressions are a class of extended regular expressions with a shuffle operator (II) and its closure (@). The class of concurrent expressions with synchronization primitives, called synchronized concurrent expressions, is intmdsccd as an extended modlel of Shaw’s flow expressions. This paper discusses sciile formal properties of synchronized(More)
We propose faster-computing methods for the minimization algorithm of AND-EXOR expressions, or Exclusive-or Sum-Of-Products expressions (ESOPs), and obtain the exact minimum ESOPs of benchmark functions. These methods improve the search procedure for ESOPs, which is the most time-consuming part of the original algorithm. For faster computation, the search(More)
Among all AND-EXOR expressions that represent a logic function f , those with a minimum number of products are called minimum AND-EXOR expressions of f . The number of products in the minimum ANDEXOR expressions of f is denoted by τ(f). The minimization algorithms of AND-EXOR expressions take a time in O(2 n ), where n is the number of variables. So it is(More)
We propose three search methods for obtaining exact minimum AND-EXOR expressions: the depth-first, the breadth-first, and the depth-first-when-optimum searches. They minimize up to 7-variable functions in a practical computation time. Experimental results to compare the efficiency of these methods are presented. The depth-first search, which saves the(More)