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Ensemble Kalman Filtering for Online Gaussian Process Regression and Learning

arXiv.org Machine Learning

Gaussian process regression is a machine learning approach which has been shown its power for estimation of unknown functions. However, Gaussian processes suffer from high computational complexity, as in a basic form they scale cubically with the number of observations. Several approaches based on inducing points were proposed to handle this problem in a static context. These methods though face challenges with real-time tasks and when the data is received sequentially over time. In this paper, a novel online algorithm for training sparse Gaussian process models is presented. It treats the mean and hyperparameters of the Gaussian process as the state and parameters of the ensemble Kalman filter, respectively. The online evaluation of the parameters and the state is performed on new upcoming samples of data. This procedure iteratively improves the accuracy of parameter estimates. The ensemble Kalman filter reduces the computational complexity required to obtain predictions with Gaussian processes preserving the accuracy level of these predictions. The performance of the proposed method is demonstrated on the synthetic dataset and real large dataset of UK house prices.


Global Smart Robot Market In-Depth Analysis On Forthcoming Development And Forecast By 2026 โ€“ Perfect Investor

#artificialintelligence

Smart Robot market research report includes the present situation and the advance estimations of the Smart Robot industry for forthcoming years 2017-2026. The Smart Robot business report covers data for the notable year 2016, the base year of evaluation is 2017. Smart Robot market report delineates the progress of the business by upstream and downstream, Smart Robot industry development, vital organizations, additionally comprise fragment, various segmentation, and makes a legitimate expectation for the development business estimates in a prospect of information. The Smart Robot statistical inspecting report is a guide, which serves current and Smart Robot future specialized and financial points of interest of the Smart Robot business to 2026. The Smart Robot report includes deep dive study of the market with around the number of tables, graphs and product figures which gives essential Smart Robot statistical information on the state of the industry and is an important source of guidance for Smart Robot companies and individuals involved in the domain.


An Overview of National AI Strategies โ€“ Politics AI โ€“ Medium

#artificialintelligence

The race to become the global leader in artificial intelligence (AI) has officially begun. In the past fifteen months, Canada, Japan, Singapore, China, the UAE, Finland, Denmark, France, the UK, the EU Commission, South Korea, and India have all released strategies to promote the use and development of AI. No two strategies are alike, with each focusing on different aspects of AI policy: scientific research, talent development, skills and education, public and private sector adoption, ethics and inclusion, standards and regulations, and data and digital infrastructure. It also highlights relevant policies and initiatives that the countries have announced since the release of their initial strategies. I plan to continuously update this article as new strategies and initiatives are announced. If a country or policy is missing (or if something in the summary is incorrect), please leave a comment and I will update the article as soon as possible.


Reasoning about exceptions in ontologies: from the lexicographic closure to the skeptical closure

arXiv.org Artificial Intelligence

Reasoning about exceptions in ontologies is nowadays one of the challenges the description logics community is facing. The paper describes a preferential approach for dealing with exceptions in Description Logics, based on the rational closure. The rational closure has the merit of providing a simple and efficient approach for reasoning with exceptions, but it does not allow independent handling of the inheritance of different defeasible properties of concepts. In this work we outline a possible solution to this problem by introducing a variant of the lexicographical closure, that we call skeptical closure, which requires to construct a single base. We develop a bi-preference semantics semantics for defining a characterization of the skeptical closure.


Separability is not the best goal for machine learning

arXiv.org Machine Learning

Neural networks use their hidden layers to transform input data into linearly separable data clusters, with a linear or a perceptron type output layer making the final projection on the line perpendicular to the discriminating hyperplane. For complex data with multimodal distributions this transformation is difficult to learn. Projection on $k\geq 2$ line segments is the simplest extension of linear separability, defining much easier goal for the learning process. Simple problems are 2-separable, but problems with inherent complex logic may be solved in a simple way by $k$-separable projections. The difficulty of learning non-linear data distributions is shifted to separation of line intervals, simplifying the transformation of data by hidden network layers. For classification of difficult Boolean problems, such as the parity problem, linear projection combined with \ksep is sufficient and provides a powerful new target for learning. More complex targets may also be defined, changing the goal of learning from linear discrimination to creation of data distributions that can easily be handled by specialized models selected to analyze output distributions. This approach can replace many layers of transformation required by deep learning models.


BALSON: Bayesian Least Squares Optimization with Nonnegative L1-Norm Constraint

arXiv.org Machine Learning

A Bayesian approach termed BAyesian Least Squares Optimization with Nonnegative L1-norm constraint (BALSON) is proposed. The error distribution of data fitting is described by Gaussian likelihood. The parameter distribution is assumed to be a Dirichlet distribution. With the Bayes rule, searching for the optimal parameters is equivalent to finding the mode of the posterior distribution. In order to explicitly characterize the nonnegative L1-norm constraint of the parameters, we further approximate the true posterior distribution by a Dirichlet distribution. We estimate the statistics of the approximating Dirichlet posterior distribution by sampling methods. Four sampling methods have been introduced. With the estimated posterior distributions, the original parameters can be effectively reconstructed in polynomial fitting problems, and the BALSON framework is found to perform better than conventional methods.


Mirror descent in saddle-point problems: Going the extra (gradient) mile

arXiv.org Machine Learning

Owing to their connection with generative adversarial networks (GANs), saddle-point problems have recently attracted considerable interest in machine learning and beyond. By necessity, most theoretical guarantees revolve around convex-concave problems; however, making theoretical inroads towards efficient GAN training crucially depends on moving beyond this classic framework. To make piecemeal progress along these lines, we analyze the widely used mirror descent (MD) method in a class of non-monotone problems - called coherent - whose solutions coincide with those of a naturally associated variational inequality. Our first result is that, under strict coherence (a condition satisfied by all strictly convex-concave problems), MD methods converge globally; however, they may fail to converge even in simple, bilinear models. To mitigate this deficiency, we add on an "extra-gradient" step which we show stabilizes MD methods by looking ahead and using a "future gradient". These theoretical results are subsequently validated by numerical experiments in GANs.


DeepSource: Point Source Detection using Deep Learning

arXiv.org Machine Learning

Point source detection at low signal-to-noise is challenging for astronomical surveys, particularly in radio interferometry images where the noise is correlated. Machine learning is a promising solution, allowing the development of algorithms tailored to specific telescope arrays and science cases. We present DeepSource - a deep learning solution - that uses convolutional neural networks to achieve these goals. DeepSource enhances the Signal-to-Noise Ratio (SNR) of the original map and then uses dynamic blob detection to detect sources. Trained and tested on two sets of 500 simulated 1 deg x 1 deg MeerKAT images with a total of 300,000 sources, DeepSource is essentially perfect in both purity and completeness down to SNR = 4 and outperforms PyBDSF in all metrics. For uniformly-weighted images it achieves a Purity x Completeness (PC) score at SNR = 3 of 0.73, compared to 0.31 for the best PyBDSF model. For natural-weighting we find a smaller improvement of ~40% in the PC score at SNR = 3. If instead we ask where either of the purity or completeness first drop to 90%, we find that DeepSource reaches this value at SNR = 3.6 compared to the 4.3 of PyBDSF (natural-weighting). A key advantage of DeepSource is that it can learn to optimally trade off purity and completeness for any science case under consideration. Our results show that deep learning is a promising approach to point source detection in astronomical images.


Driverless cars have serious health and safety benefits but the public needs to learn to trust them

Daily Mail - Science & tech

From reducing road deaths to cutting emissions, driverless cars promise huge safety benefits, however new research suggests the public are still sceptical. People's concerns around this emerging technology were brought to the fore after an automated vehicle being tested by ride-hailing service Uber killed Elaine Herzberg, 49, in Tempe, a suburb of Phoenix. Later that same month, 38-year-old Walter Huang died in an accident in California after his Tesla, which was operating on autopilot mode at the time, smashed into a median on Highway 101. Tesla co-founder Elon Musk has previously lamented about what he believes is an unfair focus on the mishaps, rather than the benefits, of autonomous vehicles. 'It's super messed up that a Tesla crash resulting in a broken ankle is front page news and the (approximately) 40,000 people who died in US auto accidents alone in past year get almost no coverage,' Musk bemoaned in a tweet bakc in May.


This DIY Polaroid Camera Draws Cartoons Using Machine Learning

#artificialintelligence

A food selfie of a nutritious salad turns into a giant hot dog, or a photo of your friends suddenly includes a barn animal: Snap a shot using this DIY, Polaroid-inspired camera, and a machine learning algorithm will interpret what it thinks it sees into a doodle drawing. Dan Macnish, a Melbourne, Australia-based engineer and artist, writes on his blog that the camera combines a neural network for object recognition, the Google Quick Draw dataset, a thermal printer, and a Raspberry Pi. Using Google's pre-trained models in TensorFlow, plus the Quick Draw dataset of 50 million simple doodles across 345 categories, he was able to code the camera to attempt to translate whatever he pointed it at into a drawing. "Attempt," because the AI doesn't always doodle its subject as you'd expect. "One of the fun things about this re-imagined polaroid is that you never get to see the original image," Macnish wrote on his blog post about the project.