電気学会論文誌C(電子・情報・システム部門誌)
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
110 巻, 10 号
選択された号の論文の6件中1~6を表示しています
  • 大塚 素子, 板倉 秀清
    1990 年 110 巻 10 号 p. 653-660
    発行日: 1990/10/20
    公開日: 2008/12/19
    ジャーナル フリー
    System level diagnosis has been studied for many years since distributed systems became available. Preparata, et al. introduced the PMC model for identifying faulty units in a system using a graph, and at the same time gave the concept of t-diagnosability. Various measures of fault diagnosability have been proposed since then. In this paper, we provide characterization theorems for two measures of fault identification capability of a system which were introduced by Somani and Amin. We consider a structure of the system which has large capability for the other measures. In Somani's model for (k, t)-diagnosability, where a t-diagnosable system suffers at most k faults at each diagnosis step, we present a polynomial algorithm for obtaining the maximum t in order for the system to be (k, t)-diagnosable given k. In Amin's model for r-weak diagnosability, where a t-diagnosable system has at most one set of r faulty units tested by at least one normal unit, we examine a structure of the system to have the maximum r.
  • Behrouz Homayoun Far, Matsuroh Nakamichi, Mitsuji Sampei
    1990 年 110 巻 10 号 p. 661-669
    発行日: 1990/10/20
    公開日: 2008/12/19
    ジャーナル フリー
    We introduce the Qualitative Sensitivity Analysis (QSA) technique and its application to generate automatically diagnostic rules for systems modeled in rule based causal format. The rule set is composed of atomic propositions. First, we introduce the Modified Causal Ordering (MCO) technique to derive ordering among the propositions. The result of MCO are complete subsets of propositions and Ordinal Reachability Graph (ORG). Each complete subset is identified by its ranking code. In QSA, propositions stand for the landmarks of the qualitative variables. QSA begins with the ORG and replaces the propositions with their equivalent landmarks. Perturbation is modeled by forcing a landmark to shift to its neighboring landmark. Sensitivity is identified as a consequence of perturbation, forcing two or more of the landmarks of a variable having the same rank. QSA can derive the sensitivity of the higher rank landmark due to perturbation affecting the lower rank ones. Applicability of the method is demonstrated through an example.
  • 桧垣 正浩, 馬渕 透, 西田 直矩
    1990 年 110 巻 10 号 p. 670-678
    発行日: 1990/10/20
    公開日: 2008/12/19
    ジャーナル フリー
    The facility location problem is one of the well-studied combinatorial optimization problems, and a number of algorithms which could find the optimal solution efficiently have been proposed. The facility location problem which considers the parametrjc analysis on demands has been studied, and this problem can handle the demand uncertainty to some extent. This paper deals with the facility location problem in which the customer's demands are given by the probability distribution functions. This model can provide more realistic information than the parametric analysis.
    Firstly, the facility location problem under demand uncertainty is formulated as a mixed integer programming problem. The objective function to be minimized is the expected value of the total cost. To prevent the algorithm from finding such solutions that are very unlikely to satisfy the demand, a constraint is imposed so as to satisfy the total demand with more than a given probability. A branch-and-bound algorithm is proposed to find the exact solution. To find the optimal solution efficiently, a procedure for calculating the lower bound is presented. Moreover, to strengthen the lower bound, the Lagrangean relaxation is applied for the constraints on demand. Lastly, to illustrate the efficiency of the proposed method, the computational experience is given.
  • 澤口 明廣, 戸田 耕司
    1990 年 110 巻 10 号 p. 679-685
    発行日: 1990/10/20
    公開日: 2008/12/19
    ジャーナル フリー
    A system of measuring the distribution of the surface acoustic wave (SAW) velocity on a test sample is constructed by incorporating leaky Lamb wave interdigital transducers (IDT). The ultrasonic bulk wave, which is mode-converted in a form of the radiation into a liquid from a leaky SAW on the surface of the test sample, is obtained as a delayed electrical signal at a recieving IDT. The phase diference of the output signals obtained at two IDTs on the same substrate surface depends on the leaky SAW velocity. It is essential for the measurement of the SAW velocity that the incident angle of the ultrasonic beam is nearly equal to the Rayleight angle. This means the prerequisite that the velocity of the leaky Lamb wave is very near the SAW velocity on the test piece. The system using leaky Lamb wave transducers has an advantage of having a very broad measurable region of SAW velocity over the use of a leaky SAW transducer, because of plural leaky Lamb wave modes having dispersive characteristics. Operation frequency region suitable for a measured sample can be selected from numerical analysis results on the performances of the leaky Lamb wave transducers at liquid-solid interface are shown for practical device configurations. A system for measuring SAW velocity distribution on a test sample is presented and experimental results for piezoelectric ceramic plates are successfully demonstrated.
  • 高梨 守弘, 柏木 浩光
    1990 年 110 巻 10 号 p. 686-687
    発行日: 1990/10/20
    公開日: 2008/12/19
    ジャーナル フリー
  • 井出 英人, 手島 靖文, 影山 芳之
    1990 年 110 巻 10 号 p. 688-689
    発行日: 1990/10/20
    公開日: 2008/12/19
    ジャーナル フリー
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