A technique to perform design calculations on imprecise representations of parameters has been developed and is presented. The level of imprecision in the description of design elements is typically high in the preliminary phase of engineering design. This imprecision is represented using the fuzzy calculus. Calculations can be performed using this method, to produce (imprecise) performance parameters from imprecise (input) design parameters. The Fuzzy Weighted Average technique is used to perform these calculations. A new metric, called the γ-level measure, is introduced to determine the relative coupling between imprecise inputs and outputs. The background and theory supporting this approach are presented, along with one example. 1.

The knowledge organization of a rule-based damage assessment system of existing structures subjected to earthquake excitation is outlined in this paper. A principle of inexact inference to obtain a rational solution is presented. The fuzzy set theory and the production system with certainty factor are employed jointly in the inexact inference to deal with the continuous nature of the damage state and to attain the modularity of uncertain knowledge, respectively. The role of damage assessment of existing structures has received increasing attention recently [32,33,343. Existing structures refer to

The paper discusses the role of uncertainty in decision making involving spatially distributed systems. It focuses on engineering structures, but draws on experience with other distributed systems. Uncertainty is divided into measurable (aleatoric), modelling (epistemic) and surprisal (ontological), and the primary emphasis is on the latter. All three are involved in decision making, and the problem addressed is how to balance their different contributions, given the difficulty of achieving a common metric. The paper concentrates on surprisal uncertainty. Various strategies for assessing it are considered. The effects of surprise can be reduced by increasing system resilience, and recent work in this area is discussed. 1.