I had missed your excellent message somehow. Interesting system. I would like to backtest it (e.g., with Wealth-Lab; see http://www.wealth-lab.com ) but I need a bit more precise description.
You buy when %K crosses above %D if the oscillator is oversold (or near oversold) AND the Aroon Oscillator isn't below -50.
What exactly do you consider "oversold (or near oversold)" and "overbought (or near overbought)" levels? I see what you mean on the chart, but in order to test it with a computer, I need precise numbers.
Also, any particular reasons why you have used the NYSE Composite to illustrate your system - instead of some more popular index, like the SPX, the COMPX or the DJIA?