Publications

Aligning artificial intelligence with climate change mitigation
Lynn H. Kaack
Priya L. Donti
Emma Strubell
George Kamiya
Felix Creutzig
David Rolnick
2022-05-31
Nature Climate Change (inconnu)
doi.org
A calcium-based plasticity model for predicting long-term potentiation and depression in the neocortex
Giuseppe Chindemi
Marwan Abdellah
Oren Amsalem
Ruth Benavides-Piccione
Vincent Delattre
Michael Doron
András Ecker
Aurélien T. Jaquier
James King
Pramod Kumbhar
Caitlin Monney
Rodrigo Perin
Christian Rössert
Anil M. Tuncel
Werner Van Geit
Javier DeFelipe
Michael Graupner
Idan Segev
Henry Markram
Eilif B. Muller
Pyramidal cells (PCs) form the backbone of the layered structure of the neocortex, and plasticity of their synapses is thought to underlie l… (voir plus)earning in the brain. However, such long-term synaptic changes have been experimentally characterized between only a few types of PCs, posing a significant barrier for studying neocortical learning mechanisms. Here we introduce a model of synaptic plasticity based on data-constrained postsynaptic calcium dynamics, and show in a neocortical microcircuit model that a single parameter set is sufficient to unify the available experimental findings on long-term potentiation (LTP) and long-term depression (LTD) of PC connections. In particular, we find that the diverse plasticity outcomes across the different PC types can be explained by cell-type-specific synaptic physiology, cell morphology and innervation patterns, without requiring type-specific plasticity. Generalizing the model to in vivo extracellular calcium concentrations, we predict qualitatively different plasticity dynamics from those observed in vitro. This work provides a first comprehensive null model for LTP/LTD between neocortical PC types in vivo, and an open framework for further developing models of cortical synaptic plasticity.
2022-05-31
Nature Communications (publié)
doi.org
Conjugate Adder Net (CAddNet) - a Space-Efficient Approximate CNN
Lulan Shen
Maryam Ziaeefard
Brett Meyer
Warren Gross
James J. Clark
The AdderNet was recently developed as a way to implement deep neural networks without needing multiplication operations to combine weights … (voir plus)and inputs. Instead, absolute values of the difference between weights and inputs are used, greatly reducing the gate-level implementation complexity. Training of AdderNets is challenging, however, and the loss curves during training tend to fluctuate significantly. In this paper we propose the Conjugate Adder Network, or CAddNet, which uses the difference between the absolute values of conjugate pairs of inputs and the weights. We show that this can be implemented simply via a single minimum operation, resulting in a roughly 50% reduction in logic gate complexity as compared with AdderNets. The CAddNet method also stabilizes training as compared with AdderNets, yielding training curves similar to standard CNNs.
2022-05-31
2022 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW) (publié)
doi.org
A data-driven approach to include availability of ICU beds in the planning of the operating room
Augustin A
Jouvet P
Lahrichi N
Lodi A
Rousseau LM
2022-05-31
Omega, The International Journal of Management Science (publié)
doi.org
Gradient-based learning drives robust representations in recurrent neural networks by balancing compression and expansion.
Matthew Farrell
Stefano Recanatesi
Timothy Moore
Guillaume Lajoie
Eric Shea-Brown
Neural networks need the right representations of input data to learn. Here we ask how gradient-based learning shapes a fundamental property… (voir plus) of representations in recurrent neural networks (RNNs)—their dimensionality. Through simulations and mathematical analysis, we show how gradient descent can lead RNNs to compress the dimensionality of their representations in a way that matches task demands during training while supporting generalization to unseen examples. This can require an expansion of dimensionality in early timesteps and compression in later ones, and strongly chaotic RNNs appear particularly adept at learning this balance. Beyond helping to elucidate the power of appropriately initialized artificial RNNs, this fact has implications for neurobiology as well. Neural circuits in the brain reveal both high variability associated with chaos and low-dimensional dynamical structures. Taken together, our findings show how simple gradient-based learning rules lead neural networks to solve tasks with robust representations that generalize to new cases. Neural networks in the brain often exhibit chaotic dynamics that can be captured by a small number of dimensions. Farrell et al. find that recurrent neural networks trained with gradient-based learning rules exhibit similar features. This helps form robust but generalizable input representations.
2022-05-31
Nature Machine Intelligence (publié)
doi.org
High-Throughput and Energy-Efficient VLSI Architecture for Ordered Reliability Bits GRAND
Syed Mohsin Abbas
Thibaud Tonnellier
Furkan Ercan
Marwan Jalaleddine
Warren J. Gross
Ultrareliable low-latency communication (URLLC), a major 5G new-radio (NR) use case, is the key enabler for applications with strict reliabi… (voir plus)lity and latency requirements. These applications necessitate the use of short-length and high-rate channel codes. Guessing random additive noise decoding (GRAND) is a recently proposed maximum likelihood (ML) decoding technique for these short-length and high-rate codes. Rather than decoding the received vector, GRAND tries to infer the noise that corrupted the transmitted codeword during transmission through the communication channel. As a result, GRAND can decode any code, structured or unstructured. GRAND has hard-input as well as soft-input variants. Among these variants, ordered reliability bits GRAND (ORBGRAND) is a soft-input variant that outperforms hard-input GRAND and is suitable for parallel hardware implementation. This work reports the first hardware architecture for ORBGRAND, which achieves an average throughput of up to 42.5 Gb/s for a code length of 128 at a target frame error rate (FER) of 10−7. Furthermore, the proposed hardware can be used to decode any code as long as the length and rate constraints are met. In comparison to the GRAND with ABandonment (GRANDAB), a hard-input variant of GRAND, the proposed architecture enhances decoding performance by at least 2 dB. When compared to the state-of-the-art fast dynamic successive cancellation flip decoder (Fast-DSCF) using a 5G polar code (PC) (128, 105), the proposed ORBGRAND VLSI implementation has
2022-05-31
IEEE Transactions on Very Large Scale Integration (VLSI) Systems (publié)
doi.org
arxiv.org
Optimal Control of Network-Coupled Subsystems: Spectral Decomposition and Low-Dimensional Solutions
Shuang Gao
Aditya Mahajan
In this article, we investigate the optimal control of network-coupled subsystems with coupled dynamics and costs. The dynamics coupling may… (voir plus) be represented by the adjacency matrix, the Laplacian matrix, or any other symmetric matrix corresponding to an underlying weighted undirected graph. Cost couplings are represented by two coupling matrices which have the same eigenvectors as the coupling matrix in the dynamics. We use the spectral decomposition of these three coupling matrices to decompose the overall system into
2022-05-31
IEEE Transactions on Control of Network Systems (publié)
doi.org
arxiv.org
OptiMaP: swarm-powered Optimized 3D Mapping Pipeline for emergency response operations
Leandro R. Costa
Daniel Aloise
Luca G. Gianoli
Andrea Lodi
A smart application in sensing is mainly powered by a two-stage process comprising sensing (collect data) and computing (process data). Whil… (voir plus)e the sensing stage is typically performed locally through a dedicated Internet of Things infrastructure, the computing stage may require a powerful infrastructure in the cloud. However, when connectivity is poor and low latency becomes a requirement — as in emergency response and disaster relief operations — edge computing and ad hoc cloud paradigms come in support to keep the computing stage locally. Being local network connectivity and data processing limited, it is vital to properly optimize how the computing workload will be consumed by the local ad hoc cloud. For this purpose, we present and evaluate the swarm-powered Optimized 3D Mapping Pipeline (OptiMaP) for emergency response 3D mapping missions, which is implemented as a collaborative embedded Robot Operating System (ROS) application integrating an ad hoc telecommunication middleware.We simulate — with Software-In-The-Loop — realistic 3D mapping missions comprising up to 5 drones and 363 images covering 0.293km2. We show how the completion times of mapping missions carried out in a typical centralized manner can be dramatically reduced by two versions of the OptiMaP framework powered, respectively, by a variable neighborhood search heuristic and a greedy method.
2022-05-31
2022 18th International Conference on Distributed Computing in Sensor Systems (DCOSS) (publié)
doi.org
Optimization and Simplification of PCPA Decoder for Reed-Muller Codes
Jiajie Li
Warren J. Gross
The collapsed projection-aggregation (CPA) decoder reduces the computational complexity of the recursive projection-aggregation (RPA) decode… (voir plus)r by removing the recursive structure. From simulations, the CPA decoder has similar error-correction performance as the RPA decoder, when decoding Reed-Muller (RM) (7, 3) and (8, 2) codes. The computational complexity can be further reduced by only selecting a subset of sub-spaces, which is achieved by pruning CPA decoders. In this work, optimization methods are proposed to find the pruned CPA (PCPA) decoder with small performance loss. Furthermore, the min-sum approximation is used to replace non-linear projection and aggregation functions, and a simplified list decoder based on the syndrome check is proposed. Under the same complexity, the optimized PCPA decoder has less performance loss than randomly constructed PCPA decoders in most case. The min-sum approximation incurs less than 0.15 dB performance loss at a target frame error rate of 10−4, and the simplified list decoder does not have noticeable performance loss.
2022-05-31
IEEE Communications Letters (publié)
doi.org
Parametric Scattering Networks
Shanel Gauthier
Benjamin Therien
Laurent Alsène-Racicot
Muawiz Chaudhary
Irina Rish
Eugene Belilovsky
Michael Eickenberg
Guy Wolf
The wavelet scattering transform creates geometric invariants and deformation stability. In multiple signal domains, it has been shown to yi… (voir plus)eld more discriminative representations compared to other non-learned representations and to outperform learned representations in certain tasks, particularly on limited labeled data and highly structured signals. The wavelet filters used in the scattering transform are typically selected to create a tight frame via a parameterized mother wavelet. In this work, we investigate whether this standard wavelet filterbank construction is optimal. Focusing on Morlet wavelets, we propose to learn the scales, orientations, and aspect ratios of the filters to produce problem-specific parameterizations of the scattering transform. We show that our learned versions of the scattering transform yield significant performance gains in small-sample classification settings over the standard scattering transform. Moreover, our empirical results suggest that traditional filterbank constructions may not always be necessary for scattering transforms to extract effective representations.
2022-05-31
2022 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) (publié)
doi.org
arxiv.org
The use of artificial intelligence and virtual reality in doctor-patient risk communication: A scoping review.
Ryan Antel
S. A. Rahimi
Elena Guadagno
Jason M. Harley
Dan Poenaru
2022-05-31
Patient Education and Counseling (publié)
doi.org
Towards an AAK Theory Approach to Approximate Minimization in the Multi-Letter Case
Clara Lacroce
Prakash Panangaden
Guillaume Rabusseau
We study the approximate minimization problem of weighted finite automata (WFAs): given a WFA, we want to compute its optimal approximation … (voir plus)when restricted to a given size. We reformulate the problem as a rank-minimization task in the spectral norm, and propose a framework to apply Adamyan-Arov-Krein (AAK) theory to the approximation problem. This approach has already been successfully applied to the case of WFAs and language modelling black boxes over one-letter alphabets \citep{AAK-WFA,AAK-RNN}. Extending the result to multi-letter alphabets requires solving the following two steps. First, we need to reformulate the approximation problem in terms of noncommutative Hankel operators and noncommutative functions, in order to apply results from multivariable operator theory. Secondly, to obtain the optimal approximation we need a version of noncommutative AAK theory that is constructive. In this paper, we successfully tackle the first step, while the second challenge remains open.
2022-05-31
ArXiv (prépublication)
doi.org
arxiv.org