Europe
General Tensor Spectral Co-clustering for Higher-Order Data
Tao Wu, Austin R. Benson, David F. Gleich
Spectral clustering and co-clustering are well-known techniques in data analysis, and recent work has extended spectral clustering to square, symmetric tensors and hypermatrices derived from a network. We develop a new tensor spectral co-clustering method that simultaneously clusters the rows, columns, and slices of a nonnegative three-mode tensor and generalizes to tensors with any number of modes. The algorithm is based on a new random walk model which we call the super-spacey random surfer. We show that our method out-performs state-of-the-art co-clustering methods on several synthetic datasets with ground truth clusters and then use the algorithm to analyze several real-world datasets.
Dueling Bandits: Beyond Condorcet Winners to General Tournament Solutions
Siddartha Y. Ramamohan, Arun Rajkumar, Shivani Agarwal, Shivani Agarwal
Recent work on deriving O(log T) anytime regret bounds for stochastic dueling bandit problems has considered mostly Condorcet winners, which do not always exist, and more recently, winners defined by the Copeland set, which do always exist. In this work, we consider a broad notion of winners defined by tournament solutions in social choice theory, which include the Copeland set as a special case but also include several other notions of winners such as the top cycle, uncovered set, and Banks set, and which, like the Copeland set, always exist. We develop a family of UCB-style dueling bandit algorithms for such general tournament solutions, and show O(log T) anytime regret bounds for them. Experiments confirm the ability of our algorithms to achieve low regret relative to the target winning set of interest.
End-to-End Kernel Learning with Supervised Convolutional Kernel Networks
In this paper, we introduce a new image representation based on a multilayer kernel machine. Unlike traditional kernel methods where data representation is decoupled from the prediction task, we learn how to shape the kernel with supervision. We proceed by first proposing improvements of the recently-introduced convolutional kernel networks (CKNs) in the context of unsupervised learning; then, we derive backpropagation rules to take advantage of labeled training data. The resulting model is a new type of convolutional neural network, where optimizing the filters at each layer is equivalent to learning a linear subspace in a reproducing kernel Hilbert space (RKHS). We show that our method achieves reasonably competitive performance for image classification on some standard "deep learning" datasets such as CIFAR-10 and SVHN, and also for image super-resolution, demonstrating the applicability of our approach to a large variety of image-related tasks.
Mixed vine copulas as joint models of spike counts and local field potentials
Concurrent measurements of neural activity at multiple scales, sometimes performed with multimodal techniques, become increasingly important for studying brain function. However, statistical methods for their concurrent analysis are currently lacking. Here we introduce such techniques in a framework based on vine copulas with mixed margins to construct multivariate stochastic models. These models can describe detailed mixed interactions between discrete variables such as neural spike counts, and continuous variables such as local field potentials. We propose efficient methods for likelihood calculation, inference, sampling and mutual information estimation within this framework. We test our methods on simulated data and demonstrate applicability on mixed data generated by a biologically realistic neural network. Our methods hold the promise to considerably improve statistical analysis of neural data recorded simultaneously at different scales.
Met police in talks to buy Palantir AI tech for use in criminal investigations
Scotland Yard is understood to be moving quickly towards embracing AI automation in its intelligence units. Scotland Yard is understood to be moving quickly towards embracing AI automation in its intelligence units. The Metropolitan police has held talks with Palantir that could lead to the London force buying the US spy-tech company's AI technology to automate intelligence analysis for criminal investigations, the Guardian has learned. Palantir, whose software is used by Donald Trump's ICE immigration enforcement programme and the Israeli military, demonstrated its systems to senior officers in the intelligence division at the UK's largest police force last month. Intelligence staff have been tasked with finding intelligence systems that AI could automate to increase productivity.
Emma the joke-telling robot cracks up the care home: Paula Hornickel's best photograph
'She had big googly eyes and was wearing a red hat knitted by one of the careworkers' Emma the Social Robot by Paula Hornickel. 'She had big googly eyes and was wearing a red hat knitted by one of the careworkers' Emma the Social Robot by Paula Hornickel. 'The first resident that Emma - a social robot - was introduced to was called Peter. After that, Emma assumed they were all called Peter, which everyone found hilarious. O ne morning in July 2025, I arrived in the small, quiet town of Albershausen in south-west Germany.