Europe
Structure Learning in Graphical Modeling
Drton, Mathias, Maathuis, Marloes H.
A graphical model is a statistical model that is associated to a graph whose nodes correspond to variables of interest. The edges of the graph reflect allowed conditional dependencies among the variables. Graphical models admit computationally convenient factorization properties and have long been a valuable tool for tractable modeling of multivariate distributions. More recently, applications such as reconstructing gene regulatory networks from gene expression data have driven major advances in structure learning, that is, estimating the graph underlying a model. We review some of these advances and discuss methods such as the graphical lasso and neighborhood selection for undirected graphical models (or Markov random fields), and the PC algorithm and score-based search methods for directed graphical models (or Bayesian networks).
Application of the Signature Method to Pattern Recognition in the CEQUEL Clinical Trial
Kormilitzin, A. B., Saunders, K. E. A., Harrison, P. J., Geddes, J. R., Lyons, T. J.
The analysis of streaming data is one of the biggest challenges posed by the expansion of digital healthcare and bioinformatics. A data stream is a sequence of data that arrives over time. Familiar examples are stock prices, sensor data from mobile devices, personal data from monitoring platforms and many more. The field of machine learning and data mining offers various frameworks for discovering patterns, hidden information, and learning the functional dependencies in complex data. Most methods in machine learning require a good choice of characteristic features to learn functions or compute the posterior probabilities.
A Novel Approach for Phase Identification in Smart Grids Using Graph Theory and Principal Component Analysis
Jayadev, P Satya, Rajeswaran, Aravind, Bhatt, Nirav P, Pasumarthy, Ramkrishna
Consumers with low demand, like households, are generally supplied single-phase power by connecting their service mains to one of the phases of a distribution transformer. The distribution companies face the problem of keeping a record of consumer connectivity to a phase due to uninformed changes that happen. The exact phase connectivity information is important for the efficient operation and control of distribution system. We propose a new data driven approach to the problem based on Principal Component Analysis (PCA) and its Graph Theoretic interpretations, using energy measurements in equally timed short intervals, generated from smart meters. We propose an algorithm for inferring phase connectivity from noisy measurements. The algorithm is demonstrated using simulated data for phase connectivities in distribution networks.
Convolutional Neural Network for Stereotypical Motor Movement Detection in Autism
Rad, Nastaran Mohammadian, Bizzego, Andrea, Kia, Seyed Mostafa, Jurman, Giuseppe, Venuti, Paola, Furlanello, Cesare
Autism Spectrum Disorders (ASDs) are often associated with specific atypical postural or motor behaviors, of which Stereotypical Motor Movements (SMMs) have a specific visibility. While the identification and the quantification of SMM patterns remain complex, its automation would provide support to accurate tuning of the intervention in the therapy of autism. Therefore, it is essential to develop automatic SMM detection systems in a real world setting, taking care of strong inter-subject and intra-subject variability. Wireless accelerometer sensing technology can provide a valid infrastructure for real-time SMM detection, however such variability remains a problem also for machine learning methods, in particular whenever handcrafted features extracted from accelerometer signal are considered. Here, we propose to employ the deep learning paradigm in order to learn discriminating features from multi-sensor accelerometer signals. Our results provide preliminary evidence that feature learning and transfer learning embedded in the deep architecture achieve higher accurate SMM detectors in longitudinal scenarios.
Revealed Preference at Scale: Learning Personalized Preferences from Assortment Choices
Kallus, Nathan, Udell, Madeleine
We consider the problem of learning the preferences of a heterogeneous population by observing choices from an assortment of products, ads, or other offerings. Our observation model takes a form common in assortment planning applications: each arriving customer is offered an assortment consisting of a subset of all possible offerings; we observe only the assortment and the customer's single choice. In this paper we propose a mixture choice model with a natural underlying low-dimensional structure, and show how to estimate its parameters. In our model, the preferences of each customer or segment follow a separate parametric choice model, but the underlying structure of these parameters over all the models has low dimension. We show that a nuclear-norm regularized maximum likelihood estimator can learn the preferences of all customers using a number of observations much smaller than the number of item-customer combinations. This result shows the potential for structural assumptions to speed up learning and improve revenues in assortment planning and customization. We provide a specialized factored gradient descent algorithm and study the success of the approach empirically.
How is a data-driven approach better than random choice in label space division for multi-label classification?
Szymaลski, Piotr, Kajdanowicz, Tomasz, Kersting, Kristian
We propose using five data-driven community detection approaches from social networks to partition the label space for the task of multi-label classification as an alternative to random partitioning into equal subsets as performed by RAkELd: modularity-maximizing fastgreedy and leading eigenvector, infomap, walktrap and label propagation algorithms. We construct a label co-occurence graph (both weighted an unweighted versions) based on training data and perform community detection to partition the label set. We include Binary Relevance and Label Powerset classification methods for comparison. We use gini-index based Decision Trees as the base classifier. We compare educated approaches to label space divisions against random baselines on 12 benchmark data sets over five evaluation measures. We show that in almost all cases seven educated guess approaches are more likely to outperform RAkELd than otherwise in all measures, but Hamming Loss. We show that fastgreedy and walktrap community detection methods on weighted label co-occurence graphs are 85-92% more likely to yield better F1 scores than random partitioning. Infomap on the unweighted label co-occurence graphs is on average 90% of the times better than random paritioning in terms of Subset Accuracy and 89% when it comes to Jaccard similarity. Weighted fastgreedy is better on average than RAkELd when it comes to Hamming Loss.
Feature-Level Domain Adaptation
Kouw, Wouter M., Krijthe, Jesse H., Loog, Marco, van der Maaten, Laurens J. P.
Domain adaptation is the supervised learning setting in which the training and test data are sampled from different distributions: training data is sampled from a source domain, whilst test data is sampled from a target domain. This paper proposes and studies an approach, called feature-level domain adaptation (flda), that models the dependence between the two domains by means of a feature-level transfer model that is trained to describe the transfer from source to target domain. Subsequently, we train a domain-adapted classifier by minimizing the expected loss under the resulting transfer model. For linear classifiers and a large family of loss functions and transfer models, this expected loss can be comp uted or approximated analytically, and minimized efficiently. Our empirical evaluation of flda focuses on problems comprising binary and count data in which the transfer can be naturally modeled via a dropout distribution, which allows the classifier to adapt to differences in the marginal probability of features in the source and the target domain. Our experiments on several real-world problems show that flda performs on par with state-of-the-art domain-adaptation techniques. Keywords: Domain adaptation, transfer learning, sample selection bias, covariate shift, empirical risk minimization, dropout.
Behind the Google brain: is AI a kind of technology, or strategy?
On March 2016, AlphaGo, a computer program developed by Google DeepMind, played the board game Go against Lee Sedol, the most famous Korean Go player. It beat Lee in a five-game match with a final score of 4 games to 1. The success of AlphaGo has shocked the whole world. Meanwhile, the development of artificial intelligence technology (also known as AI) has come back on table again. Based on deep learning, AlphaGo has conquered the obstacle of board game, so the next step, as people concern, does that mean AI is heading to a level of manufactural industry that machines can take over human's life? Google proved that their concerns would come true.
Google has developed a 'big red button' that can be used to interrupt artificial intelligence and stop it from causing harm
Machines are becoming more intelligent every year thanks to advances being made by companies like Google, Facebook, Microsoft, and many others. AI agents, as they're sometimes known, can already beat us at complex board games like Go and they're becoming more competent in a range of other areas. Now a London AI research lab owned by Google has carried out a study to make sure we can pull the plug on self-learning machines when we want to. DeepMind, acquired by Google for a reported 400 million in 2014, teamed up with scientists at the University of Oxford to find a way to make sure AI agents don't learn to prevent, or seek to prevent humans, from taking control. The peer-reviewed paper -- titled "Safely Interruptible Agents [PDF]" and published on the website of the Machine Intelligence Research Institute (MIRI) -- was written by Laurent Orseau, a research scientist at Google DeepMind, Stuart Armstrong at Oxford University's Future of Humanity Institute, and several others.
Star engineers to receive prestigious Academy Silver Medals - Royal Academy of Engineering
Three early-career engineers who are making a big difference in three very different areas of technology are to receive the Royal Academy's prestigious Silver Medal at the Academy Awards Dinner at the Tower of London on Thursday 23 June 2016. The Silver Medal celebrates outstanding personal contributions to UK engineering, which has resulted in successful market exploitation. Professor Dame Ann Dowling OM DBE FREng FRS, President of the Royal Academy of Engineering, says: "Damian Gardiner, Demis Hassabis and Tong Sun have all demonstrated the power of use-inspired research in taking ideas they have developed in academia and applying them to solve real-world problems. They are working with colleagues all over the world and making an enormous impact early in their careers that is both enriching academic knowledge and generating real economic benefit for the UK." Dr Damian Gardiner is taking the world of product authentication by storm, with his Cambridge University start-up company ilumink Limited acquired by Johnson Matthey's Process Technologies Division in 2015. They were keen to adopt his unique method of printing'liquid crystal' material onto any surface using an ink-jet printer.