457 research outputs found
Integer Echo State Networks: Hyperdimensional Reservoir Computing
We propose an approximation of Echo State Networks (ESN) that can be
efficiently implemented on digital hardware based on the mathematics of
hyperdimensional computing. The reservoir of the proposed Integer Echo State
Network (intESN) is a vector containing only n-bits integers (where n<8 is
normally sufficient for a satisfactory performance). The recurrent matrix
multiplication is replaced with an efficient cyclic shift operation. The intESN
architecture is verified with typical tasks in reservoir computing: memorizing
of a sequence of inputs; classifying time-series; learning dynamic processes.
Such an architecture results in dramatic improvements in memory footprint and
computational efficiency, with minimal performance loss.Comment: 10 pages, 10 figures, 1 tabl
PULP-HD: Accelerating Brain-Inspired High-Dimensional Computing on a Parallel Ultra-Low Power Platform
Computing with high-dimensional (HD) vectors, also referred to as
, is a brain-inspired alternative to computing with
scalars. Key properties of HD computing include a well-defined set of
arithmetic operations on hypervectors, generality, scalability, robustness,
fast learning, and ubiquitous parallel operations. HD computing is about
manipulating and comparing large patterns-binary hypervectors with 10,000
dimensions-making its efficient realization on minimalistic ultra-low-power
platforms challenging. This paper describes HD computing's acceleration and its
optimization of memory accesses and operations on a silicon prototype of the
PULPv3 4-core platform (1.5mm, 2mW), surpassing the state-of-the-art
classification accuracy (on average 92.4%) with simultaneous 3.7
end-to-end speed-up and 2 energy saving compared to its single-core
execution. We further explore the scalability of our accelerator by increasing
the number of inputs and classification window on a new generation of the PULP
architecture featuring bit-manipulation instruction extensions and larger
number of 8 cores. These together enable a near ideal speed-up of 18.4
compared to the single-core PULPv3
One-shot Learning for iEEG Seizure Detection Using End-to-end Binary Operations: Local Binary Patterns with Hyperdimensional Computing
This paper presents an efficient binarized algorithm for both learning and
classification of human epileptic seizures from intracranial
electroencephalography (iEEG). The algorithm combines local binary patterns
with brain-inspired hyperdimensional computing to enable end-to-end learning
and inference with binary operations. The algorithm first transforms iEEG time
series from each electrode into local binary pattern codes. Then atomic
high-dimensional binary vectors are used to construct composite representations
of seizures across all electrodes. For the majority of our patients (10 out of
16), the algorithm quickly learns from one or two seizures (i.e., one-/few-shot
learning) and perfectly generalizes on 27 further seizures. For other patients,
the algorithm requires three to six seizures for learning. Overall, our
algorithm surpasses the state-of-the-art methods for detecting 65 novel
seizures with higher specificity and sensitivity, and lower memory footprint.Comment: Published as a conference paper at the IEEE BioCAS 201
Efficient emotion recognition using hyperdimensional computing with combinatorial channel encoding and cellular automata
In this paper, a hardware-optimized approach to emotion recognition based on
the efficient brain-inspired hyperdimensional computing (HDC) paradigm is
proposed. Emotion recognition provides valuable information for human-computer
interactions, however the large number of input channels (>200) and modalities
(>3) involved in emotion recognition are significantly expensive from a memory
perspective. To address this, methods for memory reduction and optimization are
proposed, including a novel approach that takes advantage of the combinatorial
nature of the encoding process, and an elementary cellular automaton. HDC with
early sensor fusion is implemented alongside the proposed techniques achieving
two-class multi-modal classification accuracies of >76% for valence and >73%
for arousal on the multi-modal AMIGOS and DEAP datasets, almost always better
than state of the art. The required vector storage is seamlessly reduced by 98%
and the frequency of vector requests by at least 1/5. The results demonstrate
the potential of efficient hyperdimensional computing for low-power,
multi-channeled emotion recognition tasks
An EMG Gesture Recognition System with Flexible High-Density Sensors and Brain-Inspired High-Dimensional Classifier
EMG-based gesture recognition shows promise for human-machine interaction.
Systems are often afflicted by signal and electrode variability which degrades
performance over time. We present an end-to-end system combating this
variability using a large-area, high-density sensor array and a robust
classification algorithm. EMG electrodes are fabricated on a flexible substrate
and interfaced to a custom wireless device for 64-channel signal acquisition
and streaming. We use brain-inspired high-dimensional (HD) computing for
processing EMG features in one-shot learning. The HD algorithm is tolerant to
noise and electrode misplacement and can quickly learn from few gestures
without gradient descent or back-propagation. We achieve an average
classification accuracy of 96.64% for five gestures, with only 7% degradation
when training and testing across different days. Our system maintains this
accuracy when trained with only three trials of gestures; it also demonstrates
comparable accuracy with the state-of-the-art when trained with one trial
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