장용훈 교수

The flow of electrical current through a microscopic actual contact spot between two conductors is influenced by the flow through adjacent contact spots. A smoothed version of this interaction effect is developed and used to predict the contact resistance when the statistical size and spatial distribution of contact spots is known. To illustrate the use of the method, an idealized fractal rough surface is defined using the random midpoint displacement algorithm, and the size distribution of cont

Tandem welding increases productivity in gas metal arc welding (GMAW). We investigate asynchronous DC–AC pulse tandem GMAW. We analyse welding arc and droplet behaviour for two tandem welding processes, DC standard-AC pulse and DC pulse-AC pulse. Spatters were generated by attractive and repulsive arc interferences. The attractive arc interaction hinders stable droplet transfer and the repulsive one can induce short-circuiting of the hanging droplets. We examine the effect of process parameters

Based on the intelligent digital redesign (IDR) technique, this article proposes a novel method for designing a sampled-data fuzzy observer estimating a state vector of a nonlinear oscillating system. The proposed method guarantees not only the state estimation performance but also the state matching performance of the designed sampled-data fuzzy observer. The state matching aims at making the difference between the state trajectories of a redesigned sampled-data fuzzy observer and the given con