Deep Learning
The best 10 Artificial Intelligence podcasts (2020 A.I)
In a fully digitalized era, podcasting is nowadays one of the new sources of information not to be neglected in order to learn more about a subject and discover new passions. For the A.I lovers I summarize the best English podcast available. Artificial Intelligence podcast (AI podcast) is a series of conversations about technology, science, and the human condition hosted by Lex Fridman. Lex fridman is a well known MIT professor doing research in human-centered AI, deep learning, autonomous vehicules & robotics. During 1 hour you can join the conversation between the top deep learning makers like Elon Musk, Jack dorsey and more..
Artificial intelligence open-source frameworks to learn - Express Computer
Artificial Intelligence is one of the emerging technologies which tries to simulate human reasoning in AI systems. These times demand future-proofing yourself with the AI technology that is on the edge of becoming the next big evolution. When John McCarthy invented the term Artificial Intelligence in the year 1950 he wouldn't have predicted the wide future of this technology and how far it would travel. Experts predict that networked artificial intelligence will increase human effectiveness, but also threaten human autonomy, agency and ability. The spectrum of artificial intelligence is much broader and includes machine learning, artificial neural networks, deep learning and machine memory.
Uber open-sources Neuropod to unify AI frameworks and turn models into products
Uber today open-sourced Neuropod, an abstraction layer on top of existing machine learning frameworks that provides an interface for developing, training, and deploying AI models. It's designed to make it easier for researchers to build models in the framework of their choice while simplifying productization, according to the company. In both industry and academia, it's not uncommon for data scientists to use multiple frameworks during development. For example, Uber's Advanced Technologies Group (ATG) integrated Google's TensorFlow before transitioning to Facebook's PyTorch, which led to memory corruption and debugging problems when running alongside TensorFlow. Neuropod aims to prevent incompatibilities by making frameworks look the same when running a model, with out-of-the-box support for TensorFlow, PyTorch, Keras, and TorchScript.
Approximate Inverse Reinforcement Learning from Vision-based Imitation Learning
Lee, Keuntaek, Vlahov, Bogdan, Gibson, Jason, Rehg, James M., Theodorou, Evangelos A.
In this work, we present a method for obtaining an implicit objective function for vision-based navigation. The proposed methodology relies on Imitation Learning, Model Predictive Control (MPC), and Deep Learning. We use Imitation Learning as a means to do Inverse Reinforcement Learning in order to create an approximate costmap generator for a visual navigation challenge. The resulting costmap is used in conjunction with a Model Predictive Controller for real-time control and outperforms other state-of-the-art costmap generators combined with MPC in novel environments. The proposed process allows for simple training and robustness to out-of-sample data. We apply our method to the task of vision-based autonomous driving in multiple real and simulated environments using the same weights for the costmap predictor in all environments.
Graph-Aware Transformer: Is Attention All Graphs Need?
Yoo, Sanghyun, Kim, Young-Seok, Lee, Kang Hyun, Jeong, Kuhwan, Choi, Junhwi, Lee, Hoshik, Choi, Young Sang
Graphs are the natural data structure to represent relational and structural information in many domains. To cover the broad range of graph-data applications including graph classification as well as graph generation, it is desirable to have a general and flexible model consisting of an encoder and a decoder that can handle graph data. Although the representative encoder-decoder model, Transformer, shows superior performance in various tasks especially of natural language processing, it is not immediately available for graphs due to their non-sequential characteristics. To tackle this incompatibility, we propose GRaph-Aware Transformer (GRAT), the first Transformer-based model which can encode and decode whole graphs in end-to-end fashion. GRAT is featured with a self-attention mechanism adaptive to the edge information and an auto-regressive decoding mechanism based on the two-path approach consisting of sub-graph encoding path and node-and-edge generation path for each decoding step. We empirically evaluated GRAT on multiple setups including encoder-based tasks such as molecule property predictions on QM9 datasets and encoder-decoder-based tasks such as molecule graph generation in the organic molecule synthesis domain. GRAT has shown very promising results including state-of-the-art performance on 4 regression tasks in QM9 benchmark.
Recurrent Flow Networks: A Recurrent Latent Variable Model for Spatio-Temporal Density Modelling
Gammelli, Daniele, Rodrigues, Filipe
When modelling real-valued sequences, a typical approach in current RNN architectures is to use a Gaussian mixture model to describe the conditional output distribution. In this paper, we argue that mixture-based distributions could exhibit structural limitations when faced with highly complex data distributions such as for spatial densities. To address this issue, we introduce recurrent flow networks which combine deterministic and stochastic recurrent hidden states with conditional normalizing flows to form a probabilistic neural generative model capable of describing the kind of variability observed in highly structured spatio-temporal data. Inspired by the model's factorization, we further devise a structured variational inference network to approximate the intractable posterior distribution by exploiting a spatial representation of the data. We empirically evaluate our model against other generative models for sequential data on three real-world datasets for the task of spatio-temporal transportation demand modelling. Results show how the added flexibility allows our model to generate distributions matching potentially complex urban topologies.
Contrastive Multi-View Representation Learning on Graphs
Hassani, Kaveh, Khasahmadi, Amir Hosein
We introduce a self-supervised approach for learning node and graph level representations by contrasting structural views of graphs. We show that unlike visual representation learning, increasing the number of views to more than two or contrasting multi-scale encodings do not improve performance, and the best performance is achieved by contrasting encodings from first-order neighbors and a graph diffusion. We achieve new state-of-the-art results in self-supervised learning on 8 out of 8 node and graph classification benchmarks under the linear evaluation protocol. For example, on Cora (node) and Reddit-Binary (graph) classification benchmarks, we achieve 86.8% and 84.5% accuracy, which are 5.5% and 2.4% relative improvements over previous state-of-the-art. When compared to supervised baselines, our approach outperforms them in 4 out of 8 benchmarks. Source code is released at: https://github.com/kavehhassani/mvgrl
DeepFair: Deep Learning for Improving Fairness in Recommender Systems
Bobadilla, Jesús, Lara-Cabrera, Raúl, González-Prieto, Ángel, Ortega, Fernando
The lack of bias management in Recommender Systems leads to minority groups receiving unfair recommendations. Moreover, the trade-off between equity and precision makes it difficult to obtain recommendations that meet both criteria. Here we propose a Deep Learning based Collaborative Filtering algorithm that provides recommendations with an optimum balance between fairness and accuracy without knowing demographic information about the users. Experimental results show that it is possible to make fair recommendations without losing a significant proportion of accuracy.
Real-Time Model Calibration with Deep Reinforcement Learning
Tian, Yuan, Chao, Manuel Arias, Kulkarni, Chetan, Goebel, Kai, Fink, Olga
The dynamic, real-time, and accurate inference of model parameters from empirical data is of great importance in many scientific and engineering disciplines that use computational models (such as a digital twin) for the analysis and prediction of complex physical processes. However, fast and accurate inference for processes with large and high dimensional datasets cannot easily be achieved with state-of-the-art methods under noisy real-world conditions. The primary reason is that the inference of model parameters with traditional techniques based on optimisation or sampling often suffers from computational and statistical challenges, resulting in a trade-off between accuracy and deployment time. In this paper, we propose a novel framework for inference of model parameters based on reinforcement learning. The contribution of the paper is twofold: 1) We reformulate the inference problem as a tracking problem with the objective of learning a policy that forces the response of the physics-based model to follow the observations; 2) We propose the constrained Lyapunov-based actor-critic (CLAC) algorithm to enable the robust and accurate inference of physics-based model parameters in real time under noisy real-world conditions. The proposed methodology is demonstrated and evaluated on two model-based diagnostics test cases utilizing two different physics-based models of turbofan engines. The performance of the methodology is compared to that of two alternative approaches: a state update method (unscented Kalman filter) and a supervised end-to-end mapping with deep neural networks. The experimental results demonstrate that the proposed methodology outperforms all other tested methods in terms of speed and robustness, with high inference accuracy.
Neural Physicist: Learning Physical Dynamics from Image Sequences
Zhu, Baocheng, Wang, Shijun, Zhang, James
We present a novel architecture named Neural Physicist (NeurPhy) to learn physical dynamics directly from image sequences using deep neural networks. For any physical system, given the global system parameters, the time evolution of states is governed by the underlying physical laws. How to learn meaningful system representations in an end-to-end way and estimate accurate state transition dynamics facilitating long-term prediction have been long-standing challenges. In this paper, by leveraging recent progresses in representation learning and state space models (SSMs), we propose NeurPhy, which uses variational auto-encoder (VAE) to extract underlying Markovian dynamic state at each time step, neural process (NP) to extract the global system parameters, and a non-linear non-recurrent stochastic state space model to learn the physical dynamic transition. We apply NeurPhy to two physical experimental environments, i.e., damped pendulum and planetary orbits motion, and achieve promising results. Our model can not only extract the physically meaningful state representations, but also learn the state transition dynamics enabling long-term predictions for unseen image sequences. Furthermore, from the manifold dimension of the latent state space, we can easily identify the degree of freedom (DoF) of the underlying physical systems.