Statistical Learning
Data Science 2021 : Complete Data Science & Machine Learning
Data Science and Machine Learning are the hottest skills in demand but challenging to learn. Did you wish that there was one course for Data Science and Machine Learning that covers everything from Math for Machine Learning, Advance Statistics for Data Science, Data Processing, Machine Learning A-Z, Deep learning and more? Well, you have come to the right place. This Data Science and Machine Learning course has 11 projects, 250 lectures, more than 25 hours of content, one Kaggle competition project with top 1 percentile score, code templates and various quizzes. Today Data Science and Machine Learning is used in almost all the industries, including automobile, banking, healthcare, media, telecom and others.
Machine Learning Models Can Predict Persistence of Early Childhood Asthma - Pulmonology Advisor
Machine learning modules can be trained with the use of electronic health record (EHR) data to differentiate between transient and persistent cases of early childhood asthma, according the results of an analysis published in PLoS One. Researchers conducted a retrospective cohort study using data derived from the Pediatric Big Data (PBD) resource at the Children's Hospital of Philadelphia (CHOP) -- a pediatric tertiary academic medical center located in Pennsylvania. The researchers sought to develop machine learning modules that could be used to identify individuals who were diagnosed with asthma at aged 5 years or younger whose symptoms will continue to persist and who will thus continue to experience asthma-related visits. They trained 5 machine learning modules to distinguish between individuals without any subsequent asthma-related visits (transient asthma diagnosis) from those who did experience asthma-related visits from 5 to 10 years of age (persistent asthma diagnosis), based on clinical information available in these children up to 5 years of age. The PBD resource used in the current study included data obtained from the CHOP Care Network -- a primary care network of more than 30 sites -- and from CHOP Specialty Care and Surgical Centers.
A Beginner's Guide to Regression Analysis in Machine Learning
In order to understand the motivation behind regression, let's consider the following simple example. The scatter plot below shows the number of college graduates in the US from the year 2001 to 2012. Now based on the available data, what if someone asks you how many college graduates with master's degrees will there be in the year 2018? It can be seen that the number of college graduates with master's degrees increases almost linearly with the year. So by simple visual analysis, we can get a rough estimate of that number to be between 2.0 to 2.1 million.
A Sensorless Control System for an Implantable Heart Pump using a Real-time Deep Convolutional Neural Network
Fetanat, Masoud, Stevens, Michael, Hayward, Christopher, Lovell, Nigel H.
Left ventricular assist devices (LVADs) are mechanical pumps, which can be used to support heart failure (HF) patients as bridge to transplant and destination therapy. To automatically adjust the LVAD speed, a physiological control system needs to be designed to respond to variations of patient hemodynamics across a variety of clinical scenarios. These control systems require pressure feedback signals from the cardiovascular system. However, there are no suitable long-term implantable sensors available. In this study, a novel real-time deep convolutional neural network (CNN) for estimation of preload based on the LVAD flow was proposed. A new sensorless adaptive physiological control system for an LVAD pump was developed using the full dynamic form of model free adaptive control (FFDL-MFAC) and the proposed preload estimator to maintain the patient conditions in safe physiological ranges. The CNN model for preload estimation was trained and evaluated through 10-fold cross validation on 100 different patient conditions and the proposed sensorless control system was assessed on a new testing set of 30 different patient conditions across six different patient scenarios. The proposed preload estimator was extremely accurate with a correlation coefficient of 0.97, root mean squared error of 0.84 mmHg, reproducibility coefficient of 1.56 mmHg, coefficient of variation of 14.44 %, and bias of 0.29 mmHg for the testing dataset. The results also indicate that the proposed sensorless physiological controller works similarly to the preload-based physiological control system for LVAD using measured preload to prevent ventricular suction and pulmonary congestion. This study shows that the LVADs can respond appropriately to changing patient states and physiological demands without the need for additional pressure or flow measurements.
Learning for Detecting Norm Violation in Online Communities
Santos, Thiago Freitas dos, Osman, Nardine, Schorlemmer, Marco
In this paper, we focus on normative systems for online communities. The paper addresses the issue that arises when different community members interpret these norms in different ways, possibly leading to unexpected behavior in interactions, usually with norm violations that affect the individual and community experiences. To address this issue, we propose a framework capable of detecting norm violations and providing the violator with information about the features of their action that makes this action violate a norm. We build our framework using Machine Learning, with Logistic Model Trees as the classification algorithm. Since norm violations can be highly contextual, we train our model using data from the Wikipedia online community, namely data on Wikipedia edits. Our work is then evaluated with the Wikipedia use case where we focus on the norm that prohibits vandalism in Wikipedia edits.
Seeing All From a Few: Nodes Selection Using Graph Pooling for Graph Clustering
Wang, Yiming, Chang, Dongxia, Fu, Zhiqian, Zhao, Yao
Graph clustering aiming to obtain a partition of data using the graph information, has received considerable attention in recent years. However, noisy edges and nodes in the graph may make the clustering results worse. In this paper, we propose a novel dual graph embedding network(DGEN) to improve the robustness of the graph clustering to the noisy nodes and edges. DGEN is designed as a two-step graph encoder connected by a graph pooling layer, which learns the graph embedding of the selected nodes. Based on the assumption that a node and its nearest neighbors should belong to the same cluster, we devise the neighbor cluster pooling(NCPool) to select the most informative subset of vertices based on the clustering assignments of nodes and their nearest neighbor. This can effectively alleviate the impact of the noise edge to the clustering. After obtaining the clustering assignments of the selected nodes, a classifier is trained using these selected nodes and the final clustering assignments for all the nodes can be obtained by this classifier. Experiments on three benchmark graph datasets demonstrate the superiority compared with several state-of-the-art algorithms.
Data Augmentation in High Dimensional Low Sample Size Setting Using a Geometry-Based Variational Autoencoder
Chadebec, Clément, Thibeau-Sutre, Elina, Burgos, Ninon, Allassonnière, Stéphanie
In this paper, we propose a new method to perform data augmentation in a reliable way in the High Dimensional Low Sample Size (HDLSS) setting using a geometry-based variational autoencoder. Our approach combines a proper latent space modeling of the VAE seen as a Riemannian manifold with a new generation scheme which produces more meaningful samples especially in the context of small data sets. The proposed method is tested through a wide experimental study where its robustness to data sets, classifiers and training samples size is stressed. It is also validated on a medical imaging classification task on the challenging ADNI database where a small number of 3D brain MRIs are considered and augmented using the proposed VAE framework. In each case, the proposed method allows for a significant and reliable gain in the classification metrics. For instance, balanced accuracy jumps from 66.3% to 74.3% for a state-of-the-art CNN classifier trained with 50 MRIs of cognitively normal (CN) and 50 Alzheimer disease (AD) patients and from 77.7% to 86.3% when trained with 243 CN and 210 AD while improving greatly sensitivity and specificity metrics.
Ranking the information content of distance measures
Glielmo, Aldo, Zeni, Claudio, Cheng, Bingqing, Csanyi, Gabor, Laio, Alessandro
Real-world data typically contain a large number of features that are often heterogeneous in nature, relevance, and also units of measure. When assessing the similarity between data points, one can build various distance measures using subsets of these features. Using the fewest features but still retaining sufficient information about the system is crucial in many statistical learning approaches, particularly when data are sparse. We introduce a statistical test that can assess the relative information retained when using two different distance measures, and determine if they are equivalent, independent, or if one is more informative than the other. This in turn allows finding the most informative distance measure out of a pool of candidates. The approach is applied to find the most relevant policy variables for controlling the Covid-19 epidemic and to find compact yet informative representations of atomic structures, but its potential applications are wide ranging in many branches of science.
A Riemannian Newton Trust-Region Method for Fitting Gaussian Mixture Models
Sembach, Lena, Burgard, Jan Pablo, Schulz, Volker H.
Gaussian Mixture Models are a powerful tool in Data Science and Statistics that are mainly used for clustering and density approximation. The task of estimating the model parameters is in practice often solved by the Expectation Maximization (EM) algorithm which has its benefits in its simplicity and low per-iteration costs. However, the EM converges slowly if there is a large share of hidden information or overlapping clusters. Recent advances in Manifold Optimization for Gaussian Mixture Models have gained increasing interest. We introduce a formula for the Riemannian Hessian for Gaussian Mixture Models. On top, we propose a new Riemannian Newton Trust-Region method which outperforms current approaches both in terms of runtime and number of iterations.