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Abstract
Control of human-centered systems has increasingly been becoming more challenging because roles of humans are recognized as one of critical aspects in complex systems. Motivated by this, this paper presents a framework for modeling a human-involved complex system, which incorporates the concept of affordances. The formalism for human-involved systems is developed based on automata theory and Turvey's definition of affordance. The structure of the formal model is based on a hierarchical modeling concept which combines several atomic models and defines the granularity of states in systems. We consider two four levels of grains to represent human actions. The model is composed of system level (planning level) automata and sub-automata (perception level) associated with properties of human capabilities (effectivities) and system preconditions (affordances). The hierarchical FSA modeling framework could be used to provide the information of system complexity in human-involved systems with human planning activities.
Keywords
Affordance, Finite State Automata, Formalism, Computational Complexity
1. Introduction
When modeling a system, we may encounter many cases that human in the system need to be considered, because most of systems in reality have some portion of human activities. In this paper, we illustrate a descriptive formalism that can be used to characterize systems where a human(s) plays some physical roles in the system operation. A framework to develop formalisms for an affordance-based hierarchical system representation for complex systems is proposed and investigated. The framework consists of two parts: a) a set of formal models for human-involved system [based on FSA]; and b) a set of formal models for representing human perceptional elements, such as affordances and effectivities in the systems. Any system has its proper level of granularity which defines the fidelity of it. In a hierarchical manner, the system can be also defined as a 'systems of systems'. So, in this regard, modeling abstraction is a key to constructing models for applications such as developing models for simulation and controller. The proposed framework and modeling formalisms will provide generic models which are based on the human cognitive activities for lean supply chain and manufacturing systems with evolving structure in new era of predictive modeling concepts.
In addition, we investigated the complexity of models by considering grains of human cognitive activities in system models. The complexity System...