1,839 research outputs found
SEGAN: Speech Enhancement Generative Adversarial Network
Current speech enhancement techniques operate on the spectral domain and/or
exploit some higher-level feature. The majority of them tackle a limited number
of noise conditions and rely on first-order statistics. To circumvent these
issues, deep networks are being increasingly used, thanks to their ability to
learn complex functions from large example sets. In this work, we propose the
use of generative adversarial networks for speech enhancement. In contrast to
current techniques, we operate at the waveform level, training the model
end-to-end, and incorporate 28 speakers and 40 different noise conditions into
the same model, such that model parameters are shared across them. We evaluate
the proposed model using an independent, unseen test set with two speakers and
20 alternative noise conditions. The enhanced samples confirm the viability of
the proposed model, and both objective and subjective evaluations confirm the
effectiveness of it. With that, we open the exploration of generative
architectures for speech enhancement, which may progressively incorporate
further speech-centric design choices to improve their performance.Comment: 5 pages, 4 figures, accepted in INTERSPEECH 201
MorphIC: A 65-nm 738k-Synapse/mm Quad-Core Binary-Weight Digital Neuromorphic Processor with Stochastic Spike-Driven Online Learning
Recent trends in the field of neural network accelerators investigate weight
quantization as a means to increase the resource- and power-efficiency of
hardware devices. As full on-chip weight storage is necessary to avoid the high
energy cost of off-chip memory accesses, memory reduction requirements for
weight storage pushed toward the use of binary weights, which were demonstrated
to have a limited accuracy reduction on many applications when
quantization-aware training techniques are used. In parallel, spiking neural
network (SNN) architectures are explored to further reduce power when
processing sparse event-based data streams, while on-chip spike-based online
learning appears as a key feature for applications constrained in power and
resources during the training phase. However, designing power- and
area-efficient spiking neural networks still requires the development of
specific techniques in order to leverage on-chip online learning on binary
weights without compromising the synapse density. In this work, we demonstrate
MorphIC, a quad-core binary-weight digital neuromorphic processor embedding a
stochastic version of the spike-driven synaptic plasticity (S-SDSP) learning
rule and a hierarchical routing fabric for large-scale chip interconnection.
The MorphIC SNN processor embeds a total of 2k leaky integrate-and-fire (LIF)
neurons and more than two million plastic synapses for an active silicon area
of 2.86mm in 65nm CMOS, achieving a high density of 738k synapses/mm.
MorphIC demonstrates an order-of-magnitude improvement in the area-accuracy
tradeoff on the MNIST classification task compared to previously-proposed SNNs,
while having no penalty in the energy-accuracy tradeoff.Comment: This document is the paper as accepted for publication in the IEEE
Transactions on Biomedical Circuits and Systems journal (2019), the
fully-edited paper is available at
https://ieeexplore.ieee.org/document/876400
Memcapacitive Devices in Logic and Crossbar Applications
Over the last decade, memristive devices have been widely adopted in
computing for various conventional and unconventional applications. While the
integration density, memory property, and nonlinear characteristics have many
benefits, reducing the energy consumption is limited by the resistive nature of
the devices. Memcapacitors would address that limitation while still having all
the benefits of memristors. Recent work has shown that with adjusted parameters
during the fabrication process, a metal-oxide device can indeed exhibit a
memcapacitive behavior. We introduce novel memcapacitive logic gates and
memcapacitive crossbar classifiers as a proof of concept that such applications
can outperform memristor-based architectures. The results illustrate that,
compared to memristive logic gates, our memcapacitive gates consume about 7x
less power. The memcapacitive crossbar classifier achieves similar
classification performance but reduces the power consumption by a factor of
about 1,500x for the MNIST dataset and a factor of about 1,000x for the
CIFAR-10 dataset compared to a memristive crossbar. Our simulation results
demonstrate that memcapacitive devices have great potential for both Boolean
logic and analog low-power applications
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
Unsupervised Heart-rate Estimation in Wearables With Liquid States and A Probabilistic Readout
Heart-rate estimation is a fundamental feature of modern wearable devices. In
this paper we propose a machine intelligent approach for heart-rate estimation
from electrocardiogram (ECG) data collected using wearable devices. The novelty
of our approach lies in (1) encoding spatio-temporal properties of ECG signals
directly into spike train and using this to excite recurrently connected
spiking neurons in a Liquid State Machine computation model; (2) a novel
learning algorithm; and (3) an intelligently designed unsupervised readout
based on Fuzzy c-Means clustering of spike responses from a subset of neurons
(Liquid states), selected using particle swarm optimization. Our approach
differs from existing works by learning directly from ECG signals (allowing
personalization), without requiring costly data annotations. Additionally, our
approach can be easily implemented on state-of-the-art spiking-based
neuromorphic systems, offering high accuracy, yet significantly low energy
footprint, leading to an extended battery life of wearable devices. We
validated our approach with CARLsim, a GPU accelerated spiking neural network
simulator modeling Izhikevich spiking neurons with Spike Timing Dependent
Plasticity (STDP) and homeostatic scaling. A range of subjects are considered
from in-house clinical trials and public ECG databases. Results show high
accuracy and low energy footprint in heart-rate estimation across subjects with
and without cardiac irregularities, signifying the strong potential of this
approach to be integrated in future wearable devices.Comment: 51 pages, 12 figures, 6 tables, 95 references. Under submission at
Elsevier Neural Network
A Dual Sensor Computational Camera for High Quality Dark Videography
Videos captured under low light conditions suffer from severe noise. A
variety of efforts have been devoted to image/video noise suppression and made
large progress. However, in extremely dark scenarios, extensive photon
starvation would hamper precise noise modeling. Instead, developing an imaging
system collecting more photons is a more effective way for high-quality video
capture under low illuminations. In this paper, we propose to build a
dual-sensor camera to additionally collect the photons in NIR wavelength, and
make use of the correlation between RGB and near-infrared (NIR) spectrum to
perform high-quality reconstruction from noisy dark video pairs. In hardware,
we build a compact dual-sensor camera capturing RGB and NIR videos
simultaneously. Computationally, we propose a dual-channel multi-frame
attention network (DCMAN) utilizing spatial-temporal-spectral priors to
reconstruct the low-light RGB and NIR videos. In addition, we build a
high-quality paired RGB and NIR video dataset, based on which the approach can
be applied to different sensors easily by training the DCMAN model with
simulated noisy input following a physical-process-based CMOS noise model. Both
experiments on synthetic and real videos validate the performance of this
compact dual-sensor camera design and the corresponding reconstruction
algorithm in dark videography
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