Oceania
Rank-one matrix estimation: analytic time evolution of gradient descent dynamics
Bodin, Antoine, Macris, Nicolas
We consider a rank-one symmetric matrix corrupted by additive noise. The rank-one matrix is formed by an $n$-component unknown vector on the sphere of radius $\sqrt{n}$, and we consider the problem of estimating this vector from the corrupted matrix in the high dimensional limit of $n$ large, by gradient descent for a quadratic cost function on the sphere. Explicit formulas for the whole time evolution of the overlap between the estimator and unknown vector, as well as the cost, are rigorously derived. In the long time limit we recover the well known spectral phase transition, as a function of the signal-to-noise ratio. The explicit formulas also allow to point out interesting transient features of the time evolution. Our analysis technique is based on recent progress in random matrix theory and uses local versions of the semi-circle law.
Learning to Bridge Metric Spaces: Few-shot Joint Learning of Intent Detection and Slot Filling
Hou, Yutai, Lai, Yongkui, Chen, Cheng, Che, Wanxiang, Liu, Ting
In this paper, we investigate few-shot joint learning for dialogue language understanding. Most existing few-shot models learn a single task each time with only a few examples. However, dialogue language understanding contains two closely related tasks, i.e., intent detection and slot filling, and often benefits from jointly learning the two tasks. This calls for new few-shot learning techniques that are able to capture task relations from only a few examples and jointly learn multiple tasks. To achieve this, we propose a similarity-based few-shot learning scheme, named Contrastive Prototype Merging network (ConProm), that learns to bridge metric spaces of intent and slot on data-rich domains, and then adapt the bridged metric space to the specific few-shot domain. Experiments on two public datasets, Snips and FewJoint, show that our model significantly outperforms the strong baselines in one and five shots settings.
Practical Convex Formulation of Robust One-hidden-layer Neural Network Training
Bai, Yatong, Gautam, Tanmay, Gai, Yu, Sojoudi, Somayeh
Recent work has shown that the training of a one-hidden-layer, scalar-output fully-connected ReLU neural network can be reformulated as a finite-dimensional convex program. Unfortunately, the scale of such a convex program grows exponentially in data size. In this work, we prove that a stochastic procedure with a linear complexity well approximates the exact formulation. Moreover, we derive a convex optimization approach to efficiently solve the "adversarial training" problem, which trains neural networks that are robust to adversarial input perturbations. Our method can be applied to binary classification and regression, and provides an alternative to the current adversarial training methods, such as Fast Gradient Sign Method (FGSM) and Projected Gradient Descent (PGD). We demonstrate in experiments that the proposed method achieves a noticeably better adversarial robustness and performance than the existing methods.
Towards Teachable Autonomous Agents
Sigaud, Olivier, Caselles-Dupré, Hugo, Colas, Cédric, Akakzia, Ahmed, Oudeyer, Pierre-Yves, Chetouani, Mohamed
Autonomous discovery and direct instruction are two extreme sources of learning in children, but educational sciences have shown that intermediate approaches such as assisted discovery or guided play resulted in better acquisition of skills. When turning to Artificial Intelligence, the above dichotomy is translated into the distinction between autonomous agents which learn in isolation and interactive learning agents which can be taught by social partners but generally lack autonomy. In between should stand teachable autonomous agents: agents learning from both internal and teaching signals to benefit from the higher efficiency of assisted discovery. Such agents could learn on their own in the real world, but non-expert users could drive their learning behavior towards their expectations. More fundamentally, combining both capabilities might also be a key step towards general intelligence. In this paper we elucidate obstacles along this research line. First, we build on a seminal work of Bruner to extract relevant features of the assisted discovery processes. Second, we describe current research on autotelic agents, i.e. agents equipped with forms of intrinsic motivations that enable them to represent, self-generate and pursue their own goals. We argue that autotelic capabilities are paving the way towards teachable and autonomous agents. Finally, we adopt a social learning perspective on tutoring interactions and we highlight some components that are currently missing to autotelic agents before they can be taught by ordinary people using natural pedagogy, and we provide a list of specific research questions that emerge from this perspective.
Bi-objective Search with Bi-directional A*
Ahmadi, Saman, Tack, Guido, Harabor, Daniel, Kilby, Philip
Bi-objective search is a well-known algorithmic problem, concerned with finding a set of optimal solutions in a two-dimensional domain. This problem has a wide variety of applications such as planning in transport systems or optimal control in energy systems. Recently, bi-objective A*-based search (BOA*) has shown state-of-the-art performance in large networks. This paper develops a bi-directional variant of BOA*, enriched with several speed-up heuristics. Our experimental results on 1,000 benchmark cases show that our bi-directional A* algorithm for bi-objective search (BOBA*) can optimally solve all of the benchmark cases within the time limit, outperforming the state of the art BOA*, bi-objective Dijkstra and bi-directional bi-objective Dijkstra by an average runtime improvement of a factor of five over all of the benchmark instances.
Small and large scale critical infrastructures detection based on deep learning using high resolution orthogonal images
Francisco, Pérez-Hernández, José, Rodríguez-Ortega, Yassir, Benhammou, Francisco, Herrera, Siham, Tabik
The detection of critical infrastructures is of high importance in several fields such as security, anomaly detection, land use planning and land use change detection. However, critical infrastructures detection in aerial and satellite images is still a challenge as each one has completely different size and requires different spacial resolution to be identified correctly. Heretofore, there are no special datasets for training critical infrastructures detectors. This paper presents a smart dataset as well as a resolution-independent critical infrastructure detection system. In particular, guided by the performance of the detection model, we built a dataset organized into two scales, small and large scale, and designed a two-stage deep learning detection of different scale critical infrastructures (DetDSCI) methodology in ortho-images. DetDSCI methodology first determines the input image zoom level using a classification model, then analyses the input image with the appropriate scale detection model. Our experiments show that DetDSCI methodology achieves up to 37,53% F1 improvement with respect to the baseline detector.
Amazon will continue to ban police from using its facial recognition AI
Amazon will extend a ban it enacted last year on the use of its facial recognition for law enforcement purposes. The web giant's Rekognition service is one of the most powerful facial recognition tools available. Last year, Amazon signed a one-year moratorium that banned its use by police departments following a string of cases where facial recognition services – from various providers – were found to be inaccurate and/or misused by law enforcement. Amazon has now extended its ban indefinitely. Facial recognition services have already led to wrongful arrests that disproportionally impacted marginalised communities.
Data Validation in Machine Learning is Imperative, Not Optional - KDnuggets
Operationalizing a Machine Learning (ML) model in production needs a lot more than just creating and validating models like in academia or research. The ML application in production can be a pipeline with multiple components running consecutively as shown in Fig 1. Before we reach model training in the pipeline, there are various components like Data Ingestion, Data versioning, Data validation, and Data pre-processing that need to be executed. Data validation means checking the accuracy and quality of source data before training a new model version. It ensures that anomalies that are infrequent or manifested in incremental data are not silently ignored.
Māori are trying to save their language from Big Tech
In March 2018, Peter-Lucas Jones and the ten other staff at Te Hiku Media, a small non-profit radio station nestled just below New Zealand's most northern tip, were in disbelief. In ten days, thanks to a competition it had started, Māori speakers across New Zealand had recorded over 300 hours of annotated audio in their mother tongue. It was enough data to build language tech for te reo Māori, the Māori language – including automatic speech recognition and speech-to-text. The small staff of Māori language broadcasters and one engineer were about to become pioneers in indigenous speech recognition technology. But building the tools was only half the battle. Te Hiku soon found itself fending off corporate entities trying to develop their own indigenous data sets and resisting detrimental western approaches to data sharing.
Self-Attention Networks Can Process Bounded Hierarchical Languages
Yao, Shunyu, Peng, Binghui, Papadimitriou, Christos, Narasimhan, Karthik
Despite their impressive performance in NLP, self-attention networks were recently proved to be limited for processing formal languages with hierarchical structure, such as $\mathsf{Dyck}_k$, the language consisting of well-nested parentheses of $k$ types. This suggested that natural language can be approximated well with models that are too weak for formal languages, or that the role of hierarchy and recursion in natural language might be limited. We qualify this implication by proving that self-attention networks can process $\mathsf{Dyck}_{k, D}$, the subset of $\mathsf{Dyck}_{k}$ with depth bounded by $D$, which arguably better captures the bounded hierarchical structure of natural language. Specifically, we construct a hard-attention network with $D+1$ layers and $O(\log k)$ memory size (per token per layer) that recognizes $\mathsf{Dyck}_{k, D}$, and a soft-attention network with two layers and $O(\log k)$ memory size that generates $\mathsf{Dyck}_{k, D}$. Experiments show that self-attention networks trained on $\mathsf{Dyck}_{k, D}$ generalize to longer inputs with near-perfect accuracy, and also verify the theoretical memory advantage of self-attention networks over recurrent networks.