3,063 research outputs found
HAQ: Hardware-Aware Automated Quantization with Mixed Precision
Model quantization is a widely used technique to compress and accelerate deep
neural network (DNN) inference. Emergent DNN hardware accelerators begin to
support mixed precision (1-8 bits) to further improve the computation
efficiency, which raises a great challenge to find the optimal bitwidth for
each layer: it requires domain experts to explore the vast design space trading
off among accuracy, latency, energy, and model size, which is both
time-consuming and sub-optimal. Conventional quantization algorithm ignores the
different hardware architectures and quantizes all the layers in a uniform way.
In this paper, we introduce the Hardware-Aware Automated Quantization (HAQ)
framework which leverages the reinforcement learning to automatically determine
the quantization policy, and we take the hardware accelerator's feedback in the
design loop. Rather than relying on proxy signals such as FLOPs and model size,
we employ a hardware simulator to generate direct feedback signals (latency and
energy) to the RL agent. Compared with conventional methods, our framework is
fully automated and can specialize the quantization policy for different neural
network architectures and hardware architectures. Our framework effectively
reduced the latency by 1.4-1.95x and the energy consumption by 1.9x with
negligible loss of accuracy compared with the fixed bitwidth (8 bits)
quantization. Our framework reveals that the optimal policies on different
hardware architectures (i.e., edge and cloud architectures) under different
resource constraints (i.e., latency, energy and model size) are drastically
different. We interpreted the implication of different quantization policies,
which offer insights for both neural network architecture design and hardware
architecture design.Comment: CVPR 2019. The first three authors contributed equally to this work.
Project page: https://hanlab.mit.edu/projects/haq
Optimizing the energy consumption of spiking neural networks for neuromorphic applications
In the last few years, spiking neural networks have been demonstrated to
perform on par with regular convolutional neural networks. Several works have
proposed methods to convert a pre-trained CNN to a Spiking CNN without a
significant sacrifice of performance. We demonstrate first that
quantization-aware training of CNNs leads to better accuracy in SNNs. One of
the benefits of converting CNNs to spiking CNNs is to leverage the sparse
computation of SNNs and consequently perform equivalent computation at a lower
energy consumption. Here we propose an efficient optimization strategy to train
spiking networks at lower energy consumption, while maintaining similar
accuracy levels. We demonstrate results on the MNIST-DVS and CIFAR-10 datasets
Practical quantum realization of the ampere from the electron charge
One major change of the future revision of the International System of Units
(SI) is a new definition of the ampere based on the elementary charge \emph{e}.
Replacing the former definition based on Amp\`ere's force law will allow one to
fully benefit from quantum physics to realize the ampere. However, a quantum
realization of the ampere from \emph{e}, accurate to within in
relative value and fulfilling traceability needs, is still missing despite many
efforts have been spent for the development of single-electron tunneling
devices. Starting again with Ohm's law, applied here in a quantum circuit
combining the quantum Hall resistance and Josephson voltage standards with a
superconducting cryogenic amplifier, we report on a practical and universal
programmable quantum current generator. We demonstrate that currents generated
in the milliampere range are quantized in terms of
( is the Josephson frequency) with a measurement uncertainty of
. This new quantum current source, able to deliver such accurate
currents down to the microampere range, can greatly improve the current
measurement traceability, as demonstrated with the calibrations of digital
ammeters. Beyond, it opens the way to further developments in metrology and in
fundamental physics, such as a quantum multimeter or new accurate comparisons
to single electron pumps.Comment: 15 pages, 4 figure
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