In stochastic processes, chaos theory and time series analysis, detrended fluctuation analysis (DFA) is a method for determining the statistical self-affinity of a signal.
Sore throats caused by tonsillitis or streptococcus may trigger a canker sore even after the initial throat condition has subsided. Also known as an aphthous ulcer, canker sores are painful and unsightly, but they are not contagious.
Canker sores facts. 1  Canker sores are small, painful ulcers on the inside of the mouth, tongue, lips, or throat.  Symptoms of canker sores include small, painful, crater-like ulcers.