Goto

Collaborating Authors

 Statistical Learning


Implementation of Linear Regression

#artificialintelligence

We're going to be implementing Linear Regression on the'Boston Housing' dataset. The Boston data set contains information about the different houses in Boston. There are 506 samples and 13 feature variables in this dataset. Our aim is to predict the value of prices of the house using the given features. To get basic details about our Boston Housing dataset like null values or missing values, data types etc. we can use .info()


Understanding Causal Inference

#artificialintelligence

This article covers causal relationships and includes a chapter excerpt from the book Machine Learning in Production: Developing and Optimizing Data Science Workflows and Applications by Andrew Kelleher and Adam Kelleher. A complementary Domino project is available. As data science work is experimental and probabilistic in nature, data scientists are often faced with making inferences. This may require a shift in mindset, particularly if moving from "traditional statistical analysis to causal analysis of multivariate data". As Domino is committed to providing the platform and tools data scientists need to accelerate their work, we reached out to Addison-Wesley Professional (AWP) Pearson for permission to excerpt "Causal Inference" from the book, Machine Learning in Production: Developing and Optimizing Data Science Workflows and Applications by Andrew Kelleher and Adam Kelleher. We appreciate the permissions to provide the chapter excerpt below as well as place the code within a complementary Domino project. We've introduced [in the book] a couple of machine-learning algorithms and suggested that they can be used to produce clear, interpretable results. You've seen that logistic regression coefficients can be used to say how much more likely an outcome will occur in conjunction with a feature (for binary features) or how much more likely an outcome is to occur per unit increase in a variable (for real-valued features). We'd like to make stronger statements. We'd like to say "If you increase a variable by a unit, then it will have the effect of making an outcome more likely." These two interpretations of a regression coefficient are so similar on the surface that you may have to read them a few times to take away the meaning. The key is that in the first case, we're describing what usually happens in a system that we observe. In the second case, we're saying what will happen if we intervene in that system and disrupt it from its normal operation. After we go through an example, we'll build up the mathematical and conceptual machinery to describe interventions. We'll cover how to go from a Bayesian network describing observational data to one that describes the effects of an intervention. We'll go through some classic approaches to estimating the effects of interventions, and finally we'll explain how to use machine-learning estimators to estimate the effects of interventions.


Probabilistic Model Selection with AIC, BIC, and MDL

#artificialintelligence

Model selection is the problem of choosing one from among a set of candidate models. It is common to choose a model that performs the best on a hold-out test dataset or to estimate model performance using a resampling technique, such as k-fold cross-validation. An alternative approach to model selection involves using probabilistic statistical measures that attempt to quantify both the model performance on the training dataset and the complexity of the model. Examples include the Akaike and Bayesian Information Criterion and the Minimum Description Length. The benefit of these information criterion statistics is that they do not require a hold-out test set, although a limitation is that they do not take the uncertainty of the models into account and may end-up selecting models that are too simple.


What are Gaussian Mixture Models? A Powerful Clustering Algorithm

#artificialintelligence

They offer a completely different challenge to a supervised learning problem โ€“ there's much more room for experimenting with the data that I have. It's no wonder that the majority of developments and breakthroughs in the machine learning space are happening in the unsupervised learning domain. And one of the most popular techniques in unsupervised learning is clustering. It's a concept we typically learn early on in our machine learning journey and it's simple enough to grasp. I'm sure you've come across or even worked on projects like customer segmentation, market basket analysis, etc.


ARSM Gradient Estimator for Supervised Learning to Rank

arXiv.org Machine Learning

ABSTRACT W e propose a new model for supervised learning to rank. In our model, the relevancy labels are are assumed to follow a categorical distribution whose probabilities are constru cted based on a scoring function. Learning - to-rank methods can generally be categorized into pointwis e, pairwise, and listwise approaches. Our approach belongs to the class of pointwise methods. Although it has previously been reported that pointwise methods cannot achieve as good performance as of pairwise or listwise approaches, we show that the proposed method achieves better or comparable results on two datasets compared with pairwise and listwise methods. Index T erms-- Learning to rank, Monte Carlo Gradient Estimation, Deep learning 1. INTRODUCTION Learning to rank is fundamental to information retrieval, E-commerce, and many other applications, for ranking items [1].


Probabilistic Formulation of the Take The Best Heuristic

arXiv.org Artificial Intelligence

The framework of cognitively bounded rationality treats problem solving as fundamentally rational, but emphasises that it is constrained by cognitive architecture and the task environment. This paper investigates a simple decision making heuristic, Take The Best (TTB), within that framework. We formulate TTB as a likelihood-based probabilistic model, where the decision strategy arises by probabilistic inference based on the training data and the model constraints. The strengths of the probabilistic formulation, in addition to providing a bounded rational account of the learning of the heuristic, include natural extensibility with additional cognitively plausible constraints and prior information, and the possibility to embed the heuristic as a subpart of a larger probabilistic model. We extend the model to learn cue discrimination thresholds for continuous-valued cues and experiment with using the model to account for biased preference feedback from a boundedly rational agent in a simulated interactive machine learning task.


Variational Autoencoders for Generative Modelling of Water Cherenkov Detectors

arXiv.org Machine Learning

Matter-antimatter asymmetry is one of the major unsolved problems in physics that can be probed through precision measurements of charge-parity symmetry violation at current and next-generation neutrino oscillation experiments. In this work, we demonstrate the capability of variational autoencoders and normalizing flows to approximate the generative distribution of simulated data for water Cherenkov detectors commonly used in these experiments. We study the performance of these methods and their applicability for semi-supervised learning and synthetic data generation.


On-Device Machine Learning: An Algorithms and Learning Theory Perspective

arXiv.org Machine Learning

The current paradigm for using machine learning models on a device is to train a model in the cloud and perform inference using the trained model on the device. However, with the increasing number of smart devices and improved hardware, there is interest in performing model training on the device. Given this surge in interest, a comprehensive survey of the field from a device-agnostic perspective sets the stage for both understanding the state-of-the-art and for identifying open challenges and future avenues of research. Since on-device learning is an expansive field with connections to a large number of related topics in AI and machine learning (including online learning, model adaptation, one/few-shot learning, etc), covering such a large number of topics in a single survey is impractical. Instead, this survey finds a middle ground by reformulating the problem of on-device learning as resource constrained learning where the resources are compute and memory. This reformulation allows tools, techniques, and algorithms from a wide variety of research areas to be compared equitably. In addition to summarizing the state of the art, the survey also identifies a number of challenges and next steps for both the algorithmic and theoretical aspects of on-device learning.


Time-Aware Gated Recurrent Unit Networks for Road Surface Friction Prediction Using Historical Data

arXiv.org Machine Learning

An accurate road surface friction prediction algorithm can enable intelligent transportation systems to share timely road surface condition to the public for increasing the safety of the road users. Previously, scholars developed multiple prediction models for forecasting road surface conditions using historical data. However, road surface condition data cannot be perfectly collected at every timestamp, e.g. the data collected by on-vehicle sensors may be influenced when vehicles cannot travel due to economic cost issue or weather issues. Such resulted missing values in the collected data can damage the effectiveness and accuracy of the existing prediction methods since they are assumed to have the input data with a fixed temporal resolution. This study proposed a road surface friction prediction model employing a Gated Recurrent Unit network-based decay mechanism (GRU-D) to handle the missing values. The evaluation results present that the proposed GRU-D networks outperform all baseline models. The impact of missing rate on predictive accuracy, learning efficiency and learned decay rate are analyzed as well. The findings can help improve the prediction accuracy and efficiency of forecasting road surface friction using historical data sets with missing values, therefore mitigating the impact of wet or icy road conditions on traffic safety.


Learning Deep Bayesian Latent Variable Regression Models that Generalize: When Non-identifiability is a Problem

arXiv.org Machine Learning

Bayesian Neural Networks with Latent Variables (BNN+LV's) provide uncertainties in prediction estimates by explicitly modeling model uncertainty (via priors on network weights) and environmental stochasticity (via a latent input noise variable). In this work, we first show that BNN+LV suffers from a serious form of non-identifiability: explanatory power can be transferred between model parameters and input noise while fitting the data equally well. We demonstrate that, as a result, traditional inference methods may yield parameters that reconstruct observed data well but generalize poorly. Next, we develop a novel inference procedure that explicitly mitigates the effects of likelihood non-identifiability during training and yields high quality predictions as well as uncertainty estimates. We demonstrate that our inference method improves upon benchmark methods across a range of synthetic and real datasets.