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Temporal data classification and forecasting using a memristor-based reservoir computing system


Time-series analysis including forecasting is essential in a range of fields from finance to engineering. However, long-term forecasting is difficult, particularly for cases where the underlying models and parameters are complex and unknown. Neural networks can effectively process features in temporal units and are attractive for such purposes. Reservoir computing, in particular, can offer efficient temporal processing of recurrent neural networks with a low training cost, and is thus well suited to time-series analysis and forecasting tasks. Here, we report a reservoir computing hardware system based on dynamic tungsten oxide (WOx) memristors that can efficiently process temporal data. The internal short-term memory effects of the WOx memristors allow the memristor-based reservoir to nonlinearly map temporal inputs into reservoir states, where the projected features can be readily processed by a linear readout function. We use the system to experimentally demonstrate two standard benchmarking tasks: isolated spoken-digit recognition with partial inputs, and chaotic system forecasting. A high classification accuracy of 99.2% is obtained for spoken-digit recognition, and autonomous chaotic time-series forecasting has been demonstrated over the long term.

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Fig. 1: Memristor-based RC system.
Fig. 2: Spoken-digit recognition task implementation.
Fig. 3: Classification using partial inputs.
Fig. 4: Autonomous forecasting of Mackey–Glass time series.
Fig. 5: Long-term forecasting of Mackey–Glass time series with periodic updates.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.


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We acknowledge inspiring discussions with M. Zidan. This work was supported in part by the Defense Advanced Research Projects Agency (DARPA) through award HR0011-13-2-0015, the National Science Foundation (NSF) through grant CCF-1617315, and the Applications Driving Architectures (ADA) Research Centre, a JUMP Centre cosponsored by SRC and DARPA.

Author information




J.M., W.M. and W.D.L. conceived the project and constructed the research frame. J.M., W.M., F.C., C.D. and S.H.L. prepared the memristor arrays and built the hardware and software package. J.M. and W.M. performed the hardware measurements. J.M., W.M., J.H.S. and W.D.L. analysed the experimental data and simulation results. W.D.L. directed the project. All authors discussed the results and implications and commented on the manuscript at all stages.

Corresponding author

Correspondence to Wei D. Lu.

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The authors declare no competing interests.

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Supplementary information

Supplementary information

Supplementary Figs. 1–18, Table 1 and Notes 1–11.

Supplementary Video 1

Time evolution of the autonomously generated output from the memristor RC system, along with the ground truth of the Mackey–Glass time series, plotted in phase space.

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Moon, J., Ma, W., Shin, J.H. et al. Temporal data classification and forecasting using a memristor-based reservoir computing system. Nat Electron 2, 480–487 (2019).

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