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This paper proposes a method for interpretation of helicopter condition monitoring indicators, focusing on trend analysis rater than traditional magnitude thresholds. The method analyzes the stationarity of each indicator, and compares trend activity to a threshold database generalized to cover all aircraft of a specific model. This avoid the problem of individual threshold setting for each aircraft
This paper explores the concept of automated transition analysis of condition monitoring indicators. The proposed method uses a weighted sum of sigmoid functions to model indicator behavior over a large time-frame, and passes the sigmoid shape parameters to a fuzzy logic system. The fuzzy logic system is able to identify indicator behavior associated with normal operation, maintenance actions and...
A nonlinear dynamical model of vibration drilling is presented. It takes in consideration cutting interruption through surface generation equations. The linear stability analysis yields stability charts and the nature of Hopf bifurcation is discussed at critical values of cutting parameters. Dimensionless equations have been employed in order to obtain graphical charts that completely describe the...
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