Rule based fuzzy cognitive maps - expressing time in qualitative system dynamics

Abstract

Time is essential in the study of system dynamics. When representing and analyzing the dynamics of complex quantitative systems, the problem of expressing the "effect" of time flow is naturally solved since the mathematical equations that describe the relations between the entities of the system are a function of time. However, if we are dealing with real world qualitative systems that are impossible or difficult to model using mathematical equations, then the use of natural language becomes the best tool to represent the system and expressing time influence becomes a real issue that has not been addressed before. This paper introduces a coherent procedure to implicitly represent time in rule based fuzzy cognitive maps which are a previously introduced methodology and tool to represent and simulate the dynamics of qualitative systems.