Oceania
Chief scientist talks about AI, machine learning
During a visit to Adelaide last week, chief scientist of Australia Dr Cathy Foley very kindly agreed to join a taped panel discussion at the Royal Institution of Australia about some of her favourite science topics – AI and machine learning, and quantum computing. Hosted by Adelaide journalist and broadcaster Tory Shepherd, a regular contributor to cosmosmagazine.com, the panel included Foley, Dr Johan Verjans and Dr Vikram Sharma. Verjans is a medical specialist who combines clinical and research work. Sharma is a quantum physicist and the founder and CEO of Canberra-based QuintessenceLabs, which is a world leader in the quantum cybersecurity industry. Foley is a physicist and Australia's ninth chief scientist; her three-year term began in January 2021.
Locus: LiDAR-based Place Recognition using Spatiotemporal Higher-Order Pooling
Vidanapathirana, Kavisha, Moghadam, Peyman, Harwood, Ben, Zhao, Muming, Sridharan, Sridha, Fookes, Clinton
Place Recognition enables the estimation of a globally consistent map and trajectory by providing non-local constraints in Simultaneous Localisation and Mapping (SLAM). This paper presents Locus, a novel place recognition method using 3D LiDAR point clouds in large-scale environments. We propose a method for extracting and encoding topological and temporal information related to components in a scene and demonstrate how the inclusion of this auxiliary information in place description leads to more robust and discriminative scene representations. Second-order pooling along with a non-linear transform is used to aggregate these multi-level features to generate a fixed-length global descriptor, which is invariant to the permutation of input features. The proposed method outperforms state-of-the-art methods on the KITTI dataset. Furthermore, Locus is demonstrated to be robust across several challenging situations such as occlusions and viewpoint changes in 3D LiDAR point clouds. The open-source implementation is available at: https://github.com/csiro-robotics/locus .
Herding stochastic autonomous agents via local control rules and online global target selection strategies
Auletta, Fabrizia, Fiore, Davide, Richardson, Michael J., di Bernardo, Mario
In this Paper we propose a simple yet effective set of local control rules to make a group of "herder agents" collect and contain in a desired region an ensemble of non-cooperative stochastic "target agents" in the plane. We investigate the robustness of the proposed strategies to variations of the number of target agents and the strength of the repulsive force they feel when in proximity of the herders. Extensive numerical simulations confirm the effectiveness of the approach and are complemented by a more realistic validation on commercially available robotic agents via ROS.
Dynabench: Rethinking Benchmarking in NLP
Kiela, Douwe, Bartolo, Max, Nie, Yixin, Kaushik, Divyansh, Geiger, Atticus, Wu, Zhengxuan, Vidgen, Bertie, Prasad, Grusha, Singh, Amanpreet, Ringshia, Pratik, Ma, Zhiyi, Thrush, Tristan, Riedel, Sebastian, Waseem, Zeerak, Stenetorp, Pontus, Jia, Robin, Bansal, Mohit, Potts, Christopher, Williams, Adina
We introduce Dynabench, an open-source platform for dynamic dataset creation and model benchmarking. Dynabench runs in a web browser and supports human-and-model-in-the-loop dataset creation: annotators seek to create examples that a target model will misclassify, but that another person will not. In this paper, we argue that Dynabench addresses a critical need in our community: contemporary models quickly achieve outstanding performance on benchmark tasks but nonetheless fail on simple challenge examples and falter in real-world scenarios. With Dynabench, dataset creation, model development, and model assessment can directly inform each other, leading to more robust and informative benchmarks. We report on four initial NLP tasks, illustrating these concepts and highlighting the promise of the platform, and address potential objections to dynamic benchmarking as a new standard for the field.
Hollow-tree Super: a directional and scalable approach for feature importance in boosted tree models
Doyen, Stephane, Taylor, Hugh, Nicholas, Peter, Crawford, Lewis, Young, Isabella, Sughrue, Michael
Current limitations in boosted tree modelling prevent the effective scaling to datasets with a large feature number, particularly when investigating the magnitude and directionality of various features on classification. We present a novel methodology, Hollow-tree Super (HOTS), to resolve and visualize feature importance in boosted tree models involving a large number of features. Further, HOTS allows for investigation of the directionality and magnitude various features have on classification. Using the Iris dataset, we first compare HOTS to Gini Importance, Partial Dependence Plots, and Permutation Importance, and demonstrate how HOTS resolves the weaknesses present in these methods. We then show how HOTS can be utilized in high dimensional neuroscientific data, by taking 60 Schizophrenic subjects and applying the method to determine which brain regions were most important for classification of schizophrenia as determined by the PANSS. HOTS effectively replicated and supported the findings of Gini importance, Partial Dependence Plots and Permutation importance within the Iris dataset. When applied to the schizophrenic brain dataset, HOTS was able to resolve the top 10 most important features for classification, as well as their directionality for classification and magnitude compared to other features. Cross-validation supported that these same 10 features were consistently used in the decision-making process across multiple trees, and these features were localised primarily to the occipital and parietal cortices, commonly disturbed brain regions in those with Schizophrenia. It is imperative that a methodology is developed that is able to handle the demands of working with large datasets that contain a large number of features. HOTS represents a unique way to investigate both the directionality and magnitude of feature importance when working at scale with boosted-tree modelling.
Librispeech Transducer Model with Internal Language Model Prior Correction
Zeyer, Albert, Merboldt, André, Michel, Wilfried, Schlüter, Ralf, Ney, Hermann
We present our transducer model on Librispeech. We study variants to include an external language model (LM) with shallow fusion and subtract an estimated internal LM. This is justified by a Bayesian interpretation where the transducer model prior is given by the estimated internal LM. The subtraction of the internal LM gives us over 14% relative improvement over normal shallow fusion. Our transducer has a separate probability distribution for the non-blank labels which allows for easier combination with the external LM, and easier estimation of the internal LM. We additionally take care of including the end-of-sentence (EOS) probability of the external LM in the last blank probability which further improves the performance. All our code and setups are published.
Contrastive Explanations for Explaining Model Adaptations
Artelt, André, Hinder, Fabian, Vaquet, Valerie, Feldhans, Robert, Hammer, Barbara
Many decision making systems deployed in the real world are not static - a phenomenon known as model adaptation takes place over time. The need for transparency and interpretability of AI-based decision models is widely accepted and thus have been worked on extensively. Usually, explanation methods assume a static system that has to be explained. Explaining non-static systems is still an open research question, which poses the challenge how to explain model adaptations. In this contribution, we propose and (empirically) evaluate a framework for explaining model adaptations by contrastive explanations. We also propose a method for automatically finding regions in data space that are affected by a given model adaptation and thus should be explained.
Thousands of US government agencies are using Clearview AI without approval
Nearly two thousand government bodies, including police departments and public schools, have been using Clearview AI without oversight. Buzzfeed News reports that employees from 1,803 public bodies used the controversial facial-recognition platform without authorization from bosses. Reporters contacted a number of agency heads, many of which said they were unaware their employees were accessing the system. A database of searches, outlining which agencies were able to access the platform, and how many queries were made, was leaked to Buzzfeed by an anonymous source. It has published a version of the database online, enabling you to examine how many times each department has used the tool.
Robotic lizards may play a role in the future of disaster surveillance, researchers imagine
The university researchers built an agile contraption about the size of an average climbing lizard. The machine is nine inches long, weighs under a half-pound, and has legs and feet designed to mimic the way climbing lizards move. It is built primarily from 3-D-printed parts, with joints at the spine so it can slither and joints at the shoulders so its feet can move backward and forward. The feet have pushpins for claws, allowing them to grip into surfaces and release with ease.
Taming Adversarial Robustness via Abstaining
Makdah, Abed AlRahman Al, Katewa, Vaibhav, Pasqualetti, Fabio
In this work, we consider a binary classification problem and cast it into a binary hypothesis testing framework, where the observations can be perturbed by an adversary. To improve the adversarial robustness of a classifier, we include an abstaining option, where the classifier abstains from taking a decision when it has low confidence about the prediction. We propose metrics to quantify the nominal performance of a classifier with abstaining option and its robustness against adversarial perturbations. We show that there exist a tradeoff between the two metrics regardless of what method is used to choose the abstaining region. Our results imply that the robustness of a classifier with abstaining can only be improved at the expense of its nominal performance. Further, we provide necessary conditions to design the abstaining region for a 1-dimensional binary classification problem. We validate our theoretical results on the MNIST dataset, where we numerically show that the tradeoff between performance and robustness also exist for the general multi-class classification problems.