Africa
Digital transformation of healthcare
Cerner connects people and systems around the world by offering a range of intelligent solutions and tools that support the clinical, financial and operational needs of healthcare organisations. Dr Yasir Khan and Dr Mohamed Al Rayyes, Cerner’s Senior Physician Executives in Middle East and Africa, tell us how health information technology solutions are disrupting the industry.
On the Efficacy of Adversarial Data Collection for Question Answering: Results from a Large-Scale Randomized Study
Kaushik, Divyansh, Kiela, Douwe, Lipton, Zachary C., Yih, Wen-tau
In adversarial data collection (ADC), a human workforce interacts with a model in real time, attempting to produce examples that elicit incorrect predictions. Researchers hope that models trained on these more challenging datasets will rely less on superficial patterns, and thus be less brittle. However, despite ADC's intuitive appeal, it remains unclear when training on adversarial datasets produces more robust models. In this paper, we conduct a large-scale controlled study focused on question answering, assigning workers at random to compose questions either (i) adversarially (with a model in the loop); or (ii) in the standard fashion (without a model). Across a variety of models and datasets, we find that models trained on adversarial data usually perform better on other adversarial datasets but worse on a diverse collection of out-of-domain evaluation sets. Finally, we provide a qualitative analysis of adversarial (vs standard) data, identifying key differences and offering guidance for future research.
Tensor decomposition for learning Gaussian mixtures from moments
Khouja, Rima, Mattei, Pierre-Alexandre, Mourrain, Bernard
In data processing and machine learning, an important challenge is to recover and exploit models that can represent accurately the data. We consider the problem of recovering Gaussian mixture models from datasets. We investigate symmetric tensor decomposition methods for tackling this problem, where the tensor is built from empirical moments of the data distribution. We consider identifiable tensors, which have a unique decomposition, showing that moment tensors built from spherical Gaussian mixtures have this property. We prove that symmetric tensors with interpolation degree strictly less than half their order are identifiable and we present an algorithm, based on simple linear algebra operations, to compute their decomposition. Illustrative experimentations show the impact of the tensor decomposition method for recovering Gaussian mixtures, in comparison with other state-of-the-art approaches.
FiSH: Fair Spatial Hotspots
Pervasiveness of tracking devices and enhanced availability of spatially located data has deepened interest in using them for various policy interventions, through computational data analysis tasks such as spatial hot spot detection. In this paper, we consider, for the first time to our best knowledge, fairness in detecting spatial hot spots. We motivate the need for ensuring fairness through statistical parity over the collective population covered across chosen hot spots. We then characterize the task of identifying a diverse set of solutions in the noteworthiness-fairness trade-off spectrum, to empower the user to choose a trade-off justified by the policy domain. Being a novel task formulation, we also develop a suite of evaluation metrics for fair hot spots, motivated by the need to evaluate pertinent aspects of the task. We illustrate the computational infeasibility of identifying fair hot spots using naive and/or direct approaches and devise a method, codenamed {\it FiSH}, for efficiently identifying high-quality, fair and diverse sets of spatial hot spots. FiSH traverses the tree-structured search space using heuristics that guide it towards identifying effective and fair sets of spatial hot spots. Through an extensive empirical analysis over a real-world dataset from the domain of human development, we illustrate that FiSH generates high-quality solutions at fast response times.
Asymmetrical Bi-RNN for pedestrian trajectory encoding
Rozenberg, Raphaël, Gesnouin, Joseph, Moutarde, Fabien
Pedestrian motion behavior involves a combination of individual goals and social interactions with other agents. In this article, we present a non-symmetrical bidirectional recurrent neural network architecture called U-RNN as a sequence encoder and evaluate its relevance to replace LSTMs for various forecasting models. Experimental results on the Trajnet++ benchmark show that the U-LSTM variant can yield better results regarding every available metric (ADE, FDE, Collision rate) than common LSTMs sequence encoders for a variety of approaches and interaction modules. Our implementation of the asymmetrical Bi-RNNs for the Trajnet++ benchmark is available at: github.com/JosephGesnouin/Asymmetrical-Bi-RNNs-to-encode-pedestrian-trajectories
Rejuvenating Low-Frequency Words: Making the Most of Parallel Data in Non-Autoregressive Translation
Ding, Liang, Wang, Longyue, Liu, Xuebo, Wong, Derek F., Tao, Dacheng, Tu, Zhaopeng
Knowledge distillation (KD) is commonly used to construct synthetic data for training non-autoregressive translation (NAT) models. However, there exists a discrepancy on low-frequency words between the distilled and the original data, leading to more errors on predicting low-frequency words. To alleviate the problem, we directly expose the raw data into NAT by leveraging pretraining. By analyzing directed alignments, we found that KD makes low-frequency source words aligned with targets more deterministically but fails to align sufficient low-frequency words from target to source. Accordingly, we propose reverse KD to rejuvenate more alignments for low-frequency target words. To make the most of authentic and synthetic data, we combine these complementary approaches as a new training strategy for further boosting NAT performance. We conduct experiments on five translation benchmarks over two advanced architectures. Results demonstrate that the proposed approach can significantly and universally improve translation quality by reducing translation errors on low-frequency words. Encouragingly, our approach achieves 28.2 and 33.9 BLEU points on the WMT14 English-German and WMT16 Romanian-English datasets, respectively. Our code, data, and trained models are available at \url{https://github.com/longyuewangdcu/RLFW-NAT}.
Post-Contextual-Bandit Inference
Bibaut, Aurélien, Chambaz, Antoine, Dimakopoulou, Maria, Kallus, Nathan, van der Laan, Mark
Contextual bandit algorithms are increasingly replacing non-adaptive A/B tests in e-commerce, healthcare, and policymaking because they can both improve outcomes for study participants and increase the chance of identifying good or even best policies. To support credible inference on novel interventions at the end of the study, nonetheless, we still want to construct valid confidence intervals on average treatment effects, subgroup effects, or value of new policies. The adaptive nature of the data collected by contextual bandit algorithms, however, makes this difficult: standard estimators are no longer asymptotically normally distributed and classic confidence intervals fail to provide correct coverage. While this has been addressed in non-contextual settings by using stabilized estimators, the contextual setting poses unique challenges that we tackle for the first time in this paper. We propose the Contextual Adaptive Doubly Robust (CADR) estimator, the first estimator for policy value that is asymptotically normal under contextual adaptive data collection. The main technical challenge in constructing CADR is designing adaptive and consistent conditional standard deviation estimators for stabilization. Extensive numerical experiments using 57 OpenML datasets demonstrate that confidence intervals based on CADR uniquely provide correct coverage.
In post-pandemic Europe, migrants will face digital fortress
As the world begins to travel again, Europe is sending migrants a loud message: Stay away! Greek border police are firing bursts of deafening noise from an armored truck over the frontier into Turkey. Mounted on the vehicle, the long-range acoustic device, or "sound cannon," is the size of a small TV set but can match the volume of a jet engine. It's part of a vast array of physical and experimental new digital barriers being installed and tested during the quiet months of the coronavirus pandemic at the 200-kilometer (125-mile) Greek border with Turkey to stop people entering the European Union illegally. Nearby observation towers are being fitted with long-range cameras, night vision, and multiple sensors.
The importance of cultural diversity in AI ethics*
The quest for this Holy Grail of a universal Code of ethics in AI has left in its wake a remarkable, if not worrying, quantity of projects aiming to establish a corpus of ethical standards to frame its development. But it is vital that we question the basis on which this corpus is established. And the fast-increasing number of initiatives requiring this tool makes the necessity of ensuring the basis all the more urgent. We must ask two fundamental questions. Is it possible to create one single tool for everything and is there a real widespread desire to create such a tool?
Military drones may have attacked humans for first time without being instructed to, UN report says
A military drone may have autonomously attacked humans for the first time without being instructed to do so, according to a recent report by the UN Security Council. The report, published in March, claimed that the AI drone – Kargu-2 quadcopter – produced by Turkish military tech company STM, attacked retreating soldiers loyal to Libyan General Khalifa Haftar. The 548-page report by the UN Security Council's Panel of Experts on Libya has not delved into details on if there were any deaths due to the incident, but it raises questions on whether global efforts to ban killer autonomous robots before they are built may be futile. Over the course of the year, the UN-recognized Government of National Accord pushed the Haftar Affiliated Forces (HAF) back from the Libyan capital Tripoli, and the drone may have been operational since January 2020, the experts noted. "Logistics convoys and retreating HAF were subsequently hunted down and remotely engaged by the unmanned combat aerial vehicles or the lethal autonomous weapons systems such as the STM Kargu-2," the UN report noted.