Vibration fatigue of a vibration fatigue analysis is the modal analysis, that exposes the natural modes and frequencies of the vibrating structure and enables accurate prediction of the local stress responses for the given excitation. Only then, when the stress responses are known, can vibration fatigue be successfully characterized. The more classical approach of fatigue evaluation consists of cycle counting, using the rainflow algorithm and summation by means of the Palmgren-Miner linear damage hypothesis, that appropriately sums the damages of respective cycles. When the time history is not known, because the load is random ("e.g." a car on a rough road or
Catch per unit effort that decisions about stock management can also be made by the people doing the harvesting. The best practice is to standardise the effort employed ("e.g." number of traps or duration of searching), which controls for the reduction in catch size that often results from subsequent efforts. Although CPUE is a relative measure of abundance, it can be used to estimate absolute abundances. The main difficulty when using measures of CPUE is to define the unit of effort. Catch per unit effort In fisheries and conservation biology, the catch per unit effort (CPUE) is an indirect measure of the abundance of