Kazuo Furuta

An inference method of team situation awareness based on mutual awareness

Team situation awareness (TSA) is a critical contributing factor in establishing collaborative relations among team members involved in cooperative activity. Currently, however, there is still a lack of a clearly understandable and commonly agreeable model of TSA. To resolve misunderstanding or conflict among team members or between a team and machines, our research aim is to find out the underlying mechanism of TSA that reflects team cognitive process in a way consistent with team cooperative activity, and to focus on how to achieve mutual understanding, and how to effectively incorporate human teams into a socio-technological system. In this paper, we argue that earlier models of TSA, where TSA was discussed as the intersection of situation awareness (SA) owned by individual team members, are inadequate for study of a sophisticated team reciprocal process. We suggest that it is necessary for the definition of TSA to integrate the notion of individual SA (ISA) into cooperative team activity. In particular, understanding of mutual awareness is an essential element in cooperative activity. We propose a new notion of TSA, which is reducible to mutual beliefs as well as ISA at three levels. Further, we develop an operational TSA inference method and discuss human competence and system-related factors that are required to build TSA. We then try to demonstrate how TSA is actively constructed via inferencing practices. We also develop criteria to assess appropriateness of TSA from two aspects: soundness and completeness of mutual beliefs. Comparison of evaluation results indicates that the notion of TSA proposed in this work is more suitable to depict team cooperative activity than conventional ones.

Evacuation Planning Based on the Contraflow Technique With Consideration of Evacuation Priorities and Traffic Setup Time

Evacuation planning with the contraflow technique is a complex planning problem. The problem is further complicated when more realistic situations such as evacuation priorities and the setup time for the contraflow operation are considered. Such a complex problem has yet to be discussed in the present literature. In this paper, we present a multiple-objective optimization model for this problem and a two-layer algorithm to solve this model. Experiments on three transportation networks with different network scales are presented to show the excellent performance of the proposed model and algorithm.

On domain modelling of the service system with its application to enterprise information systems

Information systems are a kind of service systems and they are throughout every element of a modern industrial and business system, much like blood in our body. Types of information systems are heterogeneous because of extreme uncertainty in changes in modern industrial and business systems. To effectively manage information systems, modelling of the work domain (or domain) of information systems is necessary. In this paper, a domain modelling framework for the service system is proposed and its application to the enterprise information system is outlined. The framework is defined based on application of a general domain modelling tool called function-context-behaviour-principle-state-structure (FCBPSS). The FCBPSS is based on a set of core concepts, namely: function, context, behaviour, principle, state and structure and system decomposition. Different from many other applications of FCBPSS in systems engineering, the FCBPSS is applied to both infrastructure and substance systems, which is novel and effective to modelling of service systems including enterprise information systems. It is to be noted that domain modelling of systems (e.g. enterprise information systems) is a key to integration of heterogeneous systems and to coping with unanticipated situations facing to systems.

On a Unified Definition of the Service System: What is its Identity?

In this paper, a unified definition of the service system is proposed. The motivation of this research effort is based on our observation that there are diverse definitions or descriptions of the service system in the literature and they have not provided an identity of the service system. Our goal to define the service system is thus to establish its identity. The most salient feature in our definition is the introduction of three subsystems in a service system: infrastructure, substance, and management. The substance flows over the infrastructure under the constraints of management. A service is established at the moment when the substance interacts with the human to cause a change in the humans status or state under a protocol, which further meets the humans request and need. With this new definition, a service system can be distinguished from other systems, such as manufacturing system, agricultural system, and product system. The new definition will be useful to classification of various service systems and various theories for service systems, which is the key to knowledge management for service systems and to optimization of design and management of service systems.

Human Factor Analysis of JCO Criticality Accident

Abstract: The criticality accident that occurred on September 30, 1999 at a uranium processing plant in Tokai-mura was an unprecedented nuclear accident in Japan, not only because it caused deaths of two workers due to radiation casualty but also because it called for evacuation and sheltering indoors to nearby residents. The accident was not directly caused by failures or malfunctions of hardware but by workers’ unsafe action deviated from the approved procedure. It was a typical organizational accident in that several organizational factors worked behind. This article is to analyze various causal factors that lead to the accident, including situational factors of workers’ unsafe action that triggered the accident, operational and business management of the company, and nuclear safety regulation by the government. It also discusses problems of emergency response after the accident.

Evolutionary learning of fuzzy logic controllers and their adaptation through perpetual evolution

This paper presents an adaptive control architecture, where evolutionary learning is applied for initial learning and real-time tuning of a fuzzy logic controller. The initial learning phase involves identification of an artificial neural network model of the process and subsequent development of a fuzzy controller with parameters obtained via a genetic search. The neural network model is utilized for evaluating trial fuzzy controllers during the genetic search. The proposed adaptive mechanism is based on the concept of perpetual evolution, where parameters of the fuzzy controller are updated at each time step with solutions extracted from a continuously evolving population of trials. There are two mechanisms that accommodate the real-time changes in the control task and/or the process into the continuous genetic search: a scheme that dynamically modifies the fitness evaluation criteria of the genetic algorithm, and an online learning of the neural network model used for evaluating the trial controllers. The potential of using evolutionary learning for real-time adaptive control is illustrated through computer simulations, where the proposed technique is applied to a chemical process control problem.

A method for team intention inference

Recent advances in man-machine interaction include attempts to infer operator intentions from operator actions, to better anticipate and support system performance. This capability has been investigated in contexts such as intelligent interface designs and operation support systems. While some progress has been demonstrated, efforts to date have focused on a single operator. In large and complex artefacts such as power plants or aircrafts, however, a team generally operates the system, and team intention is not reducible to mere summation of individual intentions. It is therefore necessary to develop a team intention inference method for sophisticated team-machine communication. In this paper a method is proposed for team intention inference in process domains. The method uses expectations of the other members as clues to infer a team intention and describes it as a set of individual intentions and beliefs of the other team members. We applied it to the operation of a plant simulator operated by a two-person team, and it was shown that, at least in this context, the method is effective for team intention inference.

A model of team cognition based on mutual beliefs

This article proposes a generic model of team cognition based on mutual beliefs that provide foundations for the formulation of hypotheses and predictions concerning cognitive aspects of team interactions such as team situation awareness, team communication and cooperation, as well as human–agent interactions. The proposed model describes team cognition as a set of individual cognition (processes, states and mental constructs) and beliefs on the other members cognition and beliefs (mutual beliefs). One of the advantages of the introduction of the concept of mutual beliefs is that it can theoretically distinguish what is really shared among team members and what is only believed to be shared. This model also provides a framework to describe reasons and internal processes behind team interaction and communication in terms of team members cognitive status and mutual beliefs.

Display design of process systems based on functional modelling

Abstract: The prevalent way to present information in industrial computer displays is by using piping and instrumentation diagrams. Such interfaces have sometimes resulted in difficulties for operators because they are not sufficient to fulfil their needs. A systematic way that supports interface design therefore has to be considered. In the new design framework, two questions must be answered. Firstly, a modelling method is required to describe a process system. Such a modelling method can define the information content that must be displayed in interfaces. Secondly, how to communicate this information to operators efficiently must be considered. This will provide a basis for determining the visual forms that the information should take. This study discusses interface design of human–machine systems from these two points of view. Based on other scholars’ work, a comprehensive set of functional primitives is summarised as a basis to build a functional model of process systems. A library of geometrical presentations for these primitives is then developed. To support effective interface design, the concept of ‘functional macro’ is introduced and a way to map functional model to interface display is illustrated by applying several principles. To make our ideas clear, a central heating system is taken as an example and its functional model is constructed. Based on the functional model, the information to be displayed is determined. Several functional macros are then found in the model and their corresponding displays are constructed. Finally, by using the library of geometrical presentations for functional primitives and functional macros, the display hierarchy of the central heating system is developed. Reusability of functional primitives makes it possible to use the methodology to support interface design of different process systems.

An evaluation method of team situation awareness based on mutual belief

Large and complex artifacts are usually operated by a team for its safety and efficiency, and breakdowns of team cooperation sometimes cause accidents. Studies of team cooperation therefore have been drawn attention from human factors and ergonomics researchers. Team situation awareness (TSA) has been regarded as one of the important topics in such team cooperation studies. Definitions of TSA in such studies are, however, mainly based on the perspective of observers. Some studies have pointed out that it is necessary to define TSA from the perspective of “belief” that team members possess in other members’ SA in order to capture the dynamics of team cooperation. In this study, evaluation indexes of TSA from both perspectives were proposed and they were compared with team performance. The results suggest that it is necessary to evaluate team SA not only from the perspective of observers but also from the perspective of beliefs.