Detrended Fluctuation Analysis of Combat in Afghanistan

Abstract. We have tested the hypothesis that combat related data in Afghanistan for the epoch 2002-2009 demonstrates features of a complex dynamical system. To detect long-term correlations in the presence of trends, we apply detrended fluctuation analysis (DFA), a modern technique for examination of complex systems, to systematically detect and overcome nonstationarities in the data at all time scales. In every instance strong power law correlations were found, and accurate scaling exponents were obtained. It was determined that a measure of predictability was inherent in the dynamics of the system. In other words, there is a history or memory in the signal so that the future dynamics are not random but statistically correlated with past events. We also found an interesting difference in the dynamics of different types of combat events, suggesting the likelihood of different command structure.