Fundamental Study on Safety Assessment of Intelligent and Integrated Systems

这项研究的主要目的，是发展一套方法，以评估以高度精密的资讯处理技术操作和控制的智能系统的安全性。在研究计划的第一年，由于智能系统的可靠性和安全性取决于其储存知识的正确性，第二年，提出了两种基于规则的故障诊断系统中规则可靠性维护的支持方法，基于误差风险准则，研究了动态和静态系统的几种故障诊断方法。其中一种方法考虑了1）检测项目的监测值序列，2）监测值的误差，3）系统的可靠性特征，4）系统异常事件造成的损失的主观评估。第三年，重点关注人的因素以及操作和决策中的人因错误传播过程。摘要针对层次分析法（AHP）中用于确定方案相对重要性的两两比较矩阵，提出了一种新的一致性指标。通过计算机模拟AHP过程，与传统的指标相比，该指标的性能进行了检查。其次，为了分析人为错误对多人团队执行给定任务的影响，提出了一个基于人类行为模型的通用框架，并以三人团队的加油任务为例来说明所提出的方法的细节。第三，讨论了由主决策者及其下属组成的递阶团队的决策问题。一般的决策规则后，通过使用预期的错误风险标准，他们的性质进行了详细的研究。

The main objective of this research is to develop methodology to assess the safety of intelligent systems which are operated and controlled by use of highly sophisticated information processing technology.In the first year of the project, since the reliability and safety of the intelligent systems depend on the correctness of their stored knowledge, two types of supporting methods to maintain the reliability of stored ruyes in rule-based failure diagnosis systems are developed.In the second year, several failure diagnosis methods for dynamic and static systems are developed and investigated based on an error-risk criterion. One of the methods developed, for example, considers 1) sequences of monitored values of inspection items, 2) errors in monitored values, 3) reliability characteristics of the system, and 4) subjective evaluation of losses caused by system abnormal events.In the third year, human factors together with human error propagation processes in operation and decision making are focused on. Firstly, a new consistency index is proposed to the pair-wise comparison matrix which is extensively used in the Analytic Hierarchy Processes (AHP) for obtaining the relative importance of alternatives. By computer simulation of AHP processes, the properties of the proposed index are examined in comparison with the conventional index. Secondly, to analyze the effect of human errors in a team of multiple members who execute a given task, a general framework based on a human behavior model is proposed and an illustrative example of a tank-filling task for a team of three members is made to show the details of the proposed method. Thirdly, decision making by a hierarchical team which consists of a primary decision maker and his subordinates is discussed. After general decision making rules are derived by use of an expected error-risk criterion, their properties are exploited in detail.