Using wavelet-based multiresolution analysis, this study investigates the effect of hydrogen addition on cyclic variability in a natural gas spark ignition engine. The engine is operated at 3000rpm, and a lean combustible mixture with excess air ratio of 1.4 is used. Three cases are examined:...

In this paper, both the duration and the cost of an activity are modeled as random variables, and accordingly, the cumulative cost at each time point also becomes a random variable along a project’s progress. We first present the new concept of an “alphorn of uncertainty” (AoU) to describe...