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Disentangling Identifiable Features from Noisy Data with Structured Nonlinear ICA

Neural Information Processing Systems

We introduce a new general identifiable framework for principled disentanglement referred to as Structured Nonlinear Independent Component Analysis (SNICA). Our contribution is to extend the identifiability theory of deep generative models for a very broad class of structured models. While previous works have shown identifiability for specific classes of time-series models, our theorems extend this to more general temporal structures as well as to models with more complex structures such as spatial dependencies. In particular, we establish the major result that identifiability for this framework holds even in the presence of noise of unknown distribution. Finally, as an example of our framework's flexibility, we introduce the first nonlinear ICA model for time-series that combines the following very useful properties: it accounts for both nonstationarity and autocorrelation in a fully unsupervised setting; performs dimensionality reduction; models hidden states; and enables principled estimation and inference by variational maximum-likelihood.


Ambiguous Images With Human Judgments for Robust Visual Event Classification

Neural Information Processing Systems

Contemporary vision benchmarks predominantly consider tasks on which humans can achieve near-perfect performance. However, humans are frequently presented with visual data that they cannot classify with 100% certainty, and models trained on standard vision benchmarks achieve low performance when evaluated on this data. To address this issue, we introduce a procedure for creating datasets of ambiguous images and use it to produce SQUID-E ("Squidy"), a collection of noisy images extracted from videos. All images are annotated with ground truth values and a test set is annotated with human uncertainty judgments. We use this dataset to characterize human uncertainty in vision tasks and evaluate existing visual event classification models. Experimental results suggest that existing vision models are not sufficiently equipped to provide meaningful outputs for ambiguous images and that datasets of this nature can be used to assess and improve such models through model training and direct evaluation of model calibration. These findings motivate large-scale ambiguous dataset creation and further research focusing on noisy visual data.1



'Look, no hands': China chases the driverless dream at Beijing car show

The Guardian

A t the world's biggest car fair, which opened in Beijing on Friday, there were hundreds of manufacturers, more than 1,000 vehicles, hundreds of thousands of enthusiasts - and hardly anyone behind a wheel. China's car companies have cornered the domestic electric vehicle market, and are increasingly visible on the global stage . Now they are turning their attention to what they are betting is the future of mobility: autonomous driving. At the Beijing Auto Fair, a huge industry event that covers 380,000 square metres on the outskirts of the capital, the country's carmakers showed off a range of intelligent driving technologies. In China's cut-throat domestic market, nearly every big carmaker is investing heavily in the software and computing power needed to make "hands-free" driving a reality as they compete to offer additional perks and find new ways to generate revenue.




Reward-Free Model-Based Reinforcement Learning with Linear Function Approximation

Neural Information Processing Systems

We study the model-based reward-free reinforcement learning with linear function approximation for episodic Markov decision processes (MDPs). In this setting, the agent works in two phases. In the exploration phase, the agent interacts with the environment and collects samples without the reward. In the planning phase, the agent is given a specific reward function and uses samples collected from the exploration phase to learn a good policy. We propose a new provably efficient algorithm, called UCRL-RFE under the Linear Mixture MDP assumption, where the transition probability kernel of the MDP can be parameterized by a linear function over certain feature mappings defined on the triplet of state, action, and next state.