Semiregular cyclic variations might be dealt with by spectral density estimation.

Rudolf Wolf studied the historical record in an attempt to establish a database on past cyclic variations.

Examples of animal overpopulation caused by natural cyclic variations include:

Each band is similar to a varve: the banding is assumed to result from cyclic variations in available oxygen.

This stressful situation results in disease, death and population decline, leading to a pattern of cyclic variation in population size over time.

He's not so obvious that he doesn't add in some time delay to disguise the cyclic variation in our relative positions.

The problem is that we cannot be sure that there is no hidden cyclic variation in the list sequence that could cause bias.

Dr. Pennypacker acknowledged that this explanation of the cyclic variation in pulsar signals raised difficult questions.

They even knew about the 'precession of the equinoxes', a cyclic variation that completes one cycle every 26,000 years.

It is a procedure for detecting cyclic variations in biological time series and quantification of their probability.