Nonlinear Analysis Core
The Core currently has expertise in the following methods.
Annual Nonlinear Analysis Workshop
Every year the Core holds a workshop centered on the nonlinear analysis of human movement. Its purpose is to introduce research scientists, clinicians, educators and students to a variety of nonlinear methods. For more information please visit the Workshop’s webpage.
The current rate is $50 per hour.
How to Initiate Work with the Core
- Complete a Project Initiation Form and send it to firstname.lastname@example.org.
- This will be followed by a communication from the Core to better understand your needs.
- The Core will send a contract regarding the project.
- The Core will send a quote for the work.
- Provide to the Core data or other items needed to complete the work.
- Work commences.
- Dr. Aaron Likens, Core Director
- Mr. Benjamin Senderling, Core Coordinator
- Mr. Cory Frederick, Core Programmer
Here is a selection of recent publications. For more please see the Center’s publication page.
- Almurad, Z. M., & Delignières, D. Evenly spacing in detrended fluctuation analysis. Physica A: Statistical Mechanics and its Applications, 451, 63-69, 2016.
- Bollens, B., Crevecoeur, F., Nguyen, V., Detrembleur, C., & Lejeune, T. Does human gait exhibit comparable and reproducible long-range autocorrelations on level ground and on treadmill?. Gait & posture, 32(3), 369-373, 2010.
- Damouras, S., Chang, M. D., Sejdić, E., & Chau, T. An empirical examination of detrended fluctuation analysis for gait data. Gait & posture, 31(3), 336-340, 2010.
- Liddy, J. J., Ducharme, S. W., van Emmerik, R. E., & Haddad, J. M. Temporal correlations in human locomotion: Recommendations for sampling rate and foot strike detection. Physica A: Statistical Mechanics and its Applications, 532, 121784, 2019.
- Liddy, J. J., & Haddad, J. M. Evenly spaced Detrended Fluctuation Analysis: Selecting the number of points for the diffusion plot. Physica A: Statistical Mechanics and its Applications, 491, 233-248, 2018.
- McCamley J, Denton W, Arnold A, Raffalt PC, Yentes JM. On the calculation of sample entropy using continuous versus discrete data sets. Entropy, 20(10):764, 2018. PMC6402504.
- McCamley J, Denton W, Lyden E, Yentes JM. Measuring coupling of rhythmical time series using cross sample entropy and cross recurrence quantification analysis. Computational and Mathematical Methods in Medicine, 2017, 7960467, 2017. PMC5671691.
- Raffalt PC, Denton W, Yentes JM. On the choice of multiscale entropy algorithm of complexity in gait data. Computers in Biology and Medicine, 103:93-100, 2018. PMC6957257.
- Raffalt PC, McCamley J, Denton W, Yentes JM. Sampling frequency influences sample entropy of kinematics during walking. Medical & Biological Engineering and Computing, 57(4):759-764, 2019. PMC6450768.
- Raffalt PC, Yentes JM. Introducing statistical persistence decay – A quantification of stride-to-stride time interval dependency in human gait. Annals of Biomedical Engineering, 46(1):60-70, 2018. PMC5756114.
- Roume, C., Ezzina, S., Blain, H., & Delignières, D. Biases in the Simulation and Analysis of Fractal Processes. Computational and Mathematical Methods in Medicine, 2019.
- Terrier, P., & Reynard, F. Maximum Lyapunov exponent revisited: long-term attractor divergence of gait dynamics is highly sensitive to the noise structure of stride intervals. Gait & posture, 66, 236-241, 2018.
- Warlop, T. B., Bollens, B., Detrembleur, C., Stoquart, G., Lejeune, T., & Crevecoeur, F. Impact of series length on statistical precision and sensitivity of autocorrelation assessment in human locomotion. Human movement science, 55, 31-42, 2017.
- Yentes JM, Denton W, McCamley J, Raffalt PC, Schmid KK. Effect of parameter selection on entropy calculation for long walking trials. Gait & Posture, 60:128-124, 2018. PMC5809187.
- Yentes JM, Hunt N, Schmid KK, Kaipust JP, McGrath D, Stergiou N. The appropriate use of approximate entropy and sample entropy with short data sets. Annals of Biomedical Engineering, 41(2):349-365, 2013. PMC6549512.
- Yentes JM, Raffalt PC. On the application of entropic half-life and statistical persistence decay for quantification of time dependency in human gait. (Accepted with Journal of Biomechanics).