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 Statistical Learning


Xi-Learning: Successor Feature Transfer Learning for General Reward Functions

arXiv.org Artificial Intelligence

Transfer in Reinforcement Learning aims to improve learning performance on target tasks using knowledge from experienced source tasks. Successor features (SF) are a prominent transfer mechanism in domains where the reward function changes between tasks. They reevaluate the expected return of previously learned policies in a new target task and to transfer their knowledge. A limiting factor of the SF framework is its assumption that rewards linearly decompose into successor features and a reward weight vector. We propose a novel SF mechanism, $\xi$-learning, based on learning the cumulative discounted probability of successor features. Crucially, $\xi$-learning allows to reevaluate the expected return of policies for general reward functions. We introduce two $\xi$-learning variations, prove its convergence, and provide a guarantee on its transfer performance. Experimental evaluations based on $\xi$-learning with function approximation demonstrate the prominent advantage of $\xi$-learning over available mechanisms not only for general reward functions, but also in the case of linearly decomposable reward functions.


False Positive Detection and Prediction Quality Estimation for LiDAR Point Cloud Segmentation

arXiv.org Artificial Intelligence

We present a novel post-processing tool for semantic segmentation of LiDAR point cloud data, called LidarMetaSeg, which estimates the prediction quality segmentwise. For this purpose we compute dispersion measures based on network probability outputs as well as feature measures based on point cloud input features and aggregate them on segment level. These aggregated measures are used to train a meta classification model to predict whether a predicted segment is a false positive or not and a meta regression model to predict the segmentwise intersection over union. Both models can then be applied to semantic segmentation inferences without knowing the ground truth. In our experiments we use different LiDAR segmentation models and datasets and analyze the power of our method. We show that our results outperform other standard approaches.


Azure Machine Learning - Automobile Price Prediction Tutorial

#artificialintelligence

In this article, we'll go through a hands-on experience to build a machine learning model to predict price of automobiles. The previous article explored about Azure Machine Learning and we went through a step-by-step process to create Machine Learning Workspace in Azure, creating the compute instances and compute cluster. This article builds up to the last article – designing a full-on machine learning project. We explore on developing a machine learning model for Automobile Price Prediction in this article. The machine learning workflow are explained and discussed in detail in the process.


What Is TensorFlow 2.0?

#artificialintelligence

TensorFlow is one of the most widely used open-source library for machine learning and deep learning applications built by Google. TensorFlow 2.0 is the official second version of this library that encompasses many changes to make users more productive. Some major features highlights of TensorFlow 2.0 are: You can read more about the changes TensorFlow 2.0 encompasses in this TensorFlow's official blog. Learn how to build Machine Learning projects using TensorFlow 2.0? Enroll in this TensorFlow Course created by The Click Reader.


Machine Learning with PySpark Course

#artificialintelligence

Spark is a powerful, general purpose tool for working with Big Data. Spark transparently handles the distribution of compute tasks across a cluster. This means that operations are fast, but it also allows you to focus on the analysis rather than worry about technical details. In this course you'll learn how to get data into Spark and then delve into the three fundamental Spark Machine Learning algorithms: Linear Regression, Logistic Regression/Classifiers, and creating pipelines. With this background you'll be ready to harness the power of Spark and apply it on your own Machine Learning projects!


Time Series Analysis on Smart Home IOT with Weather data

#artificialintelligence

This paper proposes an efficient way to reduce usage or predict the future needs of appliances or power consumption by using the weather information data . Over the last few years, activity recognition in the smart home has become an active research area due to the wide range of human centric-applications. IoT brings together everything at home under one umbrella which has the potential to monitor and remote control such as air conditioning, alarm system, lighting, heating, ventilation, telephone system, tv, etc. To enhance our comfort and security with low energy consumption and energy management is one of the IoT use cases with which energy being sent out or consumed can be monitored. One can monitor each of the IoT appliances and how much power each of the devices is consuming, and easily switch between energy-efficient appliances across the day. In this case study we are going to focus on predicting the future energy consumption with the past data so that we can manage our day to day usage of appliances at home.


10 Best Machine Learning Courses Online for Beginners

#artificialintelligence

Do you want to learn Machine Learning and looking for the Best Machine Learning Courses Online for Beginners?… If yes, then this article is for you. In this article, you will find the 10 best machine learning courses online for beginners. So, give your few minutes to this article and find out the best machine learning course online for beginners. Now without any further ado, let's get started- This is one of the Best Online Courses for Machine Learning Beginners.


MMD Aggregated Two-Sample Test

arXiv.org Machine Learning

We propose a novel nonparametric two-sample test based on the Maximum Mean Discrepancy (MMD), which is constructed by aggregating tests with different kernel bandwidths. This aggregation procedure, called MMDAgg, ensures that test power is maximised over the collection of kernels used, without requiring held-out data for kernel selection (which results in a loss of test power), or arbitrary kernel choices such as the median heuristic. We work in the non-asymptotic framework, and prove that our aggregated test is minimax adaptive over Sobolev balls. Our guarantees are not restricted to a specific kernel, but hold for any product of one-dimensional translation invariant characteristic kernels which are absolutely and square integrable. Moreover, our results apply for popular numerical procedures to determine the test threshold, namely permutations and the wild bootstrap. Through numerical experiments on both synthetic and real-world datasets, we demonstrate that MMDAgg outperforms alternative state-of-the-art approaches to MMD kernel adaptation for two-sample testing.


Adaptive Conformal Inference Under Distribution Shift

arXiv.org Machine Learning

We develop methods for forming prediction sets in an online setting where the data generating distribution is allowed to vary over time in an unknown fashion. Our framework builds on ideas from conformal inference to provide a general wrapper that can be combined with any black box method that produces point predictions of the unseen label or estimated quantiles of its distribution. While previous conformal inference methods rely on the assumption that the data points are exchangeable, our adaptive approach provably achieves the desired coverage frequency over long-time intervals irrespective of the true data generating process. We accomplish this by modelling the distribution shift as a learning problem in a single parameter whose optimal value is varying over time and must be continuously re-estimated. We test our method, adaptive conformal inference, on two real world datasets and find that its predictions are robust to visible and significant distribution shifts.


DOCKSTRING: easy molecular docking yields better benchmarks for ligand design

arXiv.org Machine Learning

The field of machine learning for drug discovery is witnessing an explosion of novel methods. These methods are often benchmarked on simple physicochemical properties such as solubility or general druglikeness, which can be readily computed. However, these properties are poor representatives of objective functions in drug design, mainly because they do not depend on the candidate's interaction with the target. By contrast, molecular docking is a widely successful method in drug discovery to estimate binding affinities. However, docking simulations require a significant amount of domain knowledge to set up correctly which hampers adoption. To this end, we present DOCKSTRING, a bundle for meaningful and robust comparison of ML models consisting of three components: (1) an open-source Python package for straightforward computation of docking scores; (2) an extensive dataset of docking scores and poses of more than 260K ligands for 58 medically-relevant targets; and (3) a set of pharmaceutically-relevant benchmark tasks including regression, virtual screening, and de novo design. The Python package implements a robust ligand and target preparation protocol that allows non-experts to obtain meaningful docking scores. Our dataset is the first to include docking poses, as well as the first of its size that is a full matrix, thus facilitating experiments in multiobjective optimization and transfer learning. Overall, our results indicate that docking scores are a more appropriate evaluation objective than simple physicochemical properties, yielding more realistic benchmark tasks and molecular candidates.