Goto

Collaborating Authors

 Regression


Response to Comment on "Females engaging in adaptive hybridization prefer high-quality heterospecifics as mates"

Science

Braun et al. contend that we did not account for survival, but we did. Differential survival does not alter our conclusions, which were also robust to removing anomalous families. They ignore the study system's natural history justifying our fitness measures, while failing to account for our behavioral data. We stand by our conclusion that females adaptively choose among heterospecific males. Hybridization is adaptive if its fitness benefits outweigh its costs (1).


Joint data imputation and mechanistic modelling for simulating heart-brain interactions in incomplete datasets

arXiv.org Machine Learning

The use of mechanistic models in clinical studies is limited by the lack of multi-modal patients data representing different anatomical and physiological processes. For example, neuroimaging datasets do not provide a sufficient representation of heart features for the modeling of cardiovascular factors in brain disorders. To tackle this problem we introduce a probabilistic framework for joint cardiac data imputation and personalisation of cardiovascular mechanistic models, with application to brain studies with incomplete heart data. Our approach is based on a variational framework for the joint inference of an imputation model of cardiac information from the available features, along with a Gaussian Process emulator that can faithfully reproduce personalised cardiovascular dynamics. Experimental results on UK Biobank show that our model allows accurate imputation of missing cardiac features in datasets containing minimal heart information, e.g. systolic and diastolic blood pressures only, while jointly estimating the emulated parameters of the lumped model. This allows a novel exploration of the heart-brain joint relationship through simulation of realistic cardiac dynamics corresponding to different conditions of brain anatomy.



Bayesian Additive Regression Trees with Model Trees

arXiv.org Machine Learning

Noname manuscript No. (will be inserted by the editor) Abstract Bayesian Additive Regression Trees (BART) 1 Introduction is a tree-based machine learning method that has been successfully applied to regression and classification problems. Bayesian Additive Regression Trees (BART) is a statistical BART assumes regularisation priors on a set of method proposed by Chipman et al (2010) that has trees that work as weak learners and is very flexible for become popular in recent years due to its competitive predicting in the presence of non-linearity and highorder performance on regression and classification problems, interactions. In this paper, we introduce an extension when compared to other supervised machine learning of BART, called Model Trees BART (MOTR-methods, such as Random Forests (RF) (Breiman, 2001) BART), that considers piecewise linear functions at node and Gradient Boosting (GB) (Friedman, 2001). In MOTR-BART, differs from other tree-based methods as it controls the rather than having a unique value at node level for the structure of each tree via a prior distribution and generates prediction, a linear predictor is estimated considering the predictions via an MCMC backfitting algorithm the covariates that have been used as the split variables that is responsible for accepting and rejecting the in the corresponding tree. In our approach, local linearities proposed trees along the iterations.


Robust Regression for Machine Learning in Python

#artificialintelligence

Regression is a modeling task that involves predicting a numerical value given an input. Algorithms used for regression tasks are also referred to as "regression" algorithms, with the most widely known and perhaps most successful being linear regression. Linear regression fits a line or hyperplane that best describes the linear relationship between inputs and the target numeric value. If the data contains outlier values, the line can become biased, resulting in worse predictive performance. Robust regression refers to a suite of algorithms that are robust in the presence of outliers in training data.


Robust priors for regularized regression

arXiv.org Machine Learning

To whom correspondence should be addressed; Email: sebastian.suarez.12@ucl.ac.uk. Penalized regression approaches, like ridge regression, shrink weights toward zero but zero association is usually not a sensible prior. Inspired by simple and robust decision heuristics humans use, we constructed nonzero priors for penalized regression models that provide robust and interpretable solutions across several tasks. Our approach enables estimates from a constrained model to serve as a prior for a more general model, yielding a principled way to interpolate between models of differing complexity. We successfully applied this approach to a number of decision and classification problems, as well as analyzing simulated brain imaging data. Models with robust priors had excellent worstcase performance. Solutions followed from the form of the heuristic that was used to derive the prior. These new algorithms can serve applications in data analysis and machine learning, as well as help in understanding how people transition from novice to expert performance. Inference from data is most successful when it involves a helpful inductive bias or prior belief. Regularized regression approaches, such as ridge regression, incorporate a penalty term that complements the fit term by providing a constraint on the solution, akin to how Occam's razor favors solutions that both fit the observed data and are simple.


Splitting Gaussian Process Regression for Streaming Data

arXiv.org Machine Learning

Gaussian processes offer a flexible kernel method for regression. While Gaussian processes have many useful theoretical properties and have proven practically useful, they suffer from poor scaling in the number of observations. In particular, the cubic time complexity of updating standard Gaussian process models make them generally unsuitable for application to streaming data. We propose an algorithm for sequentially partitioning the input space and fitting a localized Gaussian process to each disjoint region. The algorithm is shown to have superior time and space complexity to existing methods, and its sequential nature permits application to streaming data. The algorithm constructs a model for which the time complexity of updating is tightly bounded above by a pre-specified parameter. To the best of our knowledge, the model is the first local Gaussian process regression model to achieve linear memory complexity. Theoretical continuity properties of the model are proven. We demonstrate the efficacy of the resulting model on multi-dimensional regression tasks for streaming data.


Time series analysis for predictive maintenance of turbofan engines

#artificialintelligence

These effects are often shown using the test set, something which is considered (very) bad practice but helps for educational purposes. Welcome to another installment of the'Exploring NASA's turbofan dataset' series. This will be the third analysis on FD001, where all engines run on the same operating condition and develop the same fault. Initially we assumed the Remaining Useful Life (RUL) of the engines to decline linearly. Clipping the RUL improved the baseline linear regression by 31% (from an RMSE of 31.95 to an RMSE of 21.90). We then switched to a Support Vector Regression and squeezed out another 6% improvement for a total RMSE of 20.54.


Introduction to Deep Learning with TensorFlow 2.0

#artificialintelligence

Introduction to Deep Learning with TensorFlow 2.0 Advanced implementation of regression model and essential tasks to be performed like feature selection in TensorFlow 2.x Bestseller What you'll learn In this course, you will learn advanced linear regression technique process and with this you can able to build any regression problem. With this intuition we will work on project: Customer Revenue Prediction. Problem Statement: A large child education toy company which sells educational tablets and gaming systems both online and in retail stores wanted to analyse the customer data. The goal of the problem is determine the following objective as shown below. Data Analysis & Preprocessing: Analyze customer data and draw the insights w.r.t revenue and based on the insights we will do data preprocessing.


Online Neural Networks for Change-Point Detection

arXiv.org Artificial Intelligence

Moments when a time series changes its behaviour are called change points. Detection of such points is a well-known problem, which can be found in many applications: quality monitoring of industrial processes, failure detection in complex systems, health monitoring, speech recognition and video analysis. Occurrence of change point implies that the state of the system is altered and its timely detection might help to prevent unwanted consequences. In this paper, we present two online change-point detection approaches based on neural networks. These algorithms demonstrate linear computational complexity and are suitable for change-point detection in large time series. We compare them with the best known algorithms on various synthetic and real world data sets. Experiments show that the proposed methods outperform known approaches.