Juro Oizumi

An Analysis of the M/G/1 Queue Under Round-Robin Scheduling

In order to discuss scheduling algorithms for time-sharing computer systems, this paper analyzes the M/G/1 queue under the well known round-robin RR discipline. Three models are considered: the constant-quantum RR model, the processor-shared or zero-quantum RR model, and the variable-quantum RR model. The paper proposes an effective calculating method for obtaining the expected response time under an arbitrary processing-time distribution with overhead. By the theoretical analysis, one can show how the response time is affected by the scheduling and processing-time distributions, as is demonstrated by some typical examples.

A structure theory of automata characterized by groups

The structure of a strongly connected permutation automaton, a quasiperfect automaton, and a perfect automaton are discussed algebraically using group theory. A characterization theorem for the three classes of automata, a condition for direct product decomposability of a strongly connected permutation automaton, and some other related results are proposed in this paper.

A characterization of automata and a direct product decomposition

The classes of automata characterized by certain semigroups are investigated: It isshown that the classes of cyclic quasi-state-independent automata, cyclic quasi-state-independent automat of monoid type, cyclic Abelian automata, strongly connected state-independent automata, strongly connected resect automata, quasi-perfect automata, and perfect automata are equivalent to the classes of automata generated by semigroups with left identity, monoids, commutative semigroups with identity, right groups, right zero semigroups, groups, and Abelian groups, respectively. The characterization of the endomorphism semigroups and the automorphism groups and the direct product decomposabilities for the above classes of automata are also given. Finally, it is shown that every regular set can be accepted by some cyclic quasi-state-independent acceptor of monoid type.

A Fundamental Consideration on Pattern Recognizers

Much research has been done in the field of the pattern recognition. It is generally classified into two types; 1. dynamic system and 2. static system. The typical model of the dynamic system is the one proposed by Caianiello [1].