Regression
Development of a Machine Learning Model and Mobile Application to Aid in Predicting Dosage of Vitamin K Antagonists Among Indian Patients
M, Amruthlal, S, Devika, A, Ameer Suhail P, Menon, Aravind K, Krishnan, Vignesh, Thomas, Alan, Thomas, Manu, G, Sanjay, R, Lakshmi Kanth L, Jose, Jimmy, S, Harikrishnan
Patients who undergo mechanical heart valve replacements or have conditions like Atrial Fibrillation have to take Vitamin K Antagonists (VKA) drugs to prevent coagulation of blood. These drugs have narrow therapeutic range and need to be very closely monitored due to life threatening side effects. The dosage of VKA drug is determined and revised by a physician based on Prothrombin Time - International Normalised Ratio (PT-INR) value obtained through a blood test. Our work aimed at predicting the maintenance dosage of warfarin, the present most widely recommended anticoagulant drug, using the de-identified medical data collected from 109 patients from Kerala. A Support Vector Machine (SVM) Regression model was built to predict the maintenance dosage of warfarin, for patients who have been undergoing treatment from a physician and have reached stable INR values between 2.0 and 4.0.
Safe Screening Rules for $\ell_0$-Regression
Atamtรผrk, Alper, Gรณmez, Andrรฉs
We give safe screening rules to eliminate variables from regression with $\ell_0$ regularization or cardinality constraint. These rules are based on guarantees that a feature may or may not be selected in an optimal solution. The screening rules can be computed from a convex relaxation solution in linear time, without solving the $\ell_0$ optimization problem. Thus, they can be used in a preprocessing step to safely remove variables from consideration apriori. Numerical experiments on real and synthetic data indicate that, on average, 76\% of the variables can be fixed to their optimal values, hence, reducing the computational burden for optimization substantially. Therefore, the proposed fast and effective screening rules extend the scope of algorithms for $\ell_0$-regression to larger data sets.
Statistical inference in massive datasets by empirical likelihood
Ma, Xuejun, Wang, Shaochen, Zhou, Wang
With the rapid development of science and technologies, massive data can be collected at a large speed, especially in internet and financial fields. It is generally recognized that two major challenges in large-scale learning are estimation and inference due to large amount of computation. For statistical inference on massive data sets, Kleiner et al. (2014) proposed the bag of little bootstrap (BLB) to assess the quality of estimators. However, they used only a small number of random subsets, and partial observations from each subset. This implies less efficiency in application.
Automatic Grading of Knee Osteoarthritis on the Kellgren-Lawrence Scale from Radiographs Using Convolutional Neural Networks
Kondal, Sudeep, Kulkarni, Viraj, Gaikwad, Ashrika, Kharat, Amit, Pant, Aniruddha
The severity of knee osteoarthritis is graded using the 5-point Kellgren-Lawrence (KL) scale where healthy knees are assigned grade 0, and the subsequent grades 1-4 represent increasing severity of the affliction. Although several methods have been proposed in recent years to develop models that can automatically predict the KL grade from a given radiograph, most models have been developed and evaluated on datasets not sourced from India. These models fail to perform well on the radiographs of Indian patients. In this paper, we propose a novel method using convolutional neural networks to automatically grade knee radiographs on the KL scale. Our method works in two connected stages: in the first stage, an object detection model segments individual knees from the rest of the image; in the second stage, a regression model automatically grades each knee separately on the KL scale. We train our model using the publicly available Osteoarthritis Initiative (OAI) dataset and demonstrate that fine-tuning the model before evaluating it on a dataset from a private hospital significantly improves the mean absolute error from 1.09 (95% CI: 1.03-1.15) to 0.28 (95% CI: 0.25-0.32). Additionally, we compare classification and regression models built for the same task and demonstrate that regression outperforms classification.
Machine learning algorithms in Python Algorithmia Blog
Python is one of the most commonly used programming languages by data scientists and machine learning engineers. Although there has been no universal study on the prevalence of machine learning algorithms in Python in machine learning, a 2019 GitHub analysis of public repositories tagged as "machine-learning" not surprisingly found that Python was the most common language used. Python outranked other languages commonly used in the data science community including R, Scala, and Julia. This is all to say that if you're interested in being a data scientist or a machine learning engineer, then understanding Python should be on your to-do list. It's important to remember though that employing machine learning techniques involves more than just coding for coding's sake.
Machine learning algorithms in Python Algorithmia Blog
Python is one of the most commonly used programming languages by data scientists and machine learning engineers. Although there has been no universal study on the prevalence of machine learning algorithms in Python in machine learning, a 2019 GitHub analysis of public repositories tagged as "machine-learning" not surprisingly found that Python was the most common language used. Python outranked other languages commonly used in the data science community including R, Scala, and Julia. This is all to say that if you're interested in being a data scientist or a machine learning engineer, then understanding Python should be on your to-do list. It's important to remember though that employing machine learning techniques involves more than just coding for coding's sake.
What is Logistic Regression? An introduction for everyone 23
Artificial Intelligence terms explained in a minute for everyone! This week's term is Logistic Regression. Ask any questions or remarks you have in the comments, I will gladly answer to everything! Subscribe to not miss any AI news and terms explained! Facebook: https://www.facebook.com/whats.artifi... Share this to someone who needs to learn more about Artificial Intelligence!
Contrastive Examples for Addressing the Tyranny of the Majority
Sharmanska, Viktoriia, Hendricks, Lisa Anne, Darrell, Trevor, Quadrianto, Novi
Computer vision algorithms, e.g. for face recognition, favour groups of individuals that are better represented in the training data. This happens because of the generalization that classifiers have to make. It is simpler to fit the majority groups as this fit is more important to overall error. We propose to create a balanced training dataset, consisting of the original dataset plus new data points in which the group memberships are intervened, minorities become majorities and vice versa. We show that current generative adversarial networks are a powerful tool for learning these data points, called contrastive examples. We experiment with the equalized odds bias measure on tabular data as well as image data (CelebA and Diversity in Faces datasets). Contrastive examples allow us to expose correlations between group membership and other seemingly neutral features. Whenever a causal graph is available, we can put those contrastive examples in the perspective of counterfactuals.
Measurement Error in Nutritional Epidemiology: A Survey
This article reviews bias-correction models for measurement error of exposure variables in the field of nutritional epidemiology. Measurement error usually attenuates estimated slope towards zero. Due to the influence of measurement error, inference of parameter estimate is conservative and confidence interval of the slope parameter is too narrow. Bias-correction in estimators and confidence intervals are of primary interest. We review the following bias-correction models: regression calibration methods, likelihood based models, missing data models, simulation based methods, nonparametric models and sampling based procedures.
How to Use One-vs-Rest and One-vs-One for Multi-Class Classification
Not all classification predictive models support multi-class classification. Algorithms such as the Perceptron, Logistic Regression, and Support Vector Machines were designed for binary classification and do not natively support classification tasks with more than two classes. One approach for using binary classification algorithms for multi-classification problems is to split the multi-class classification dataset into multiple binary classification datasets and fit a binary classification model on each. Two different examples of this approach are the One-vs-Rest and One-vs-One strategies. In this tutorial, you will discover One-vs-Rest and One-vs-One strategies for multi-class classification.