Accuracy
Statistical Agnostic Mapping: a Framework in Neuroimaging based on Concentration Inequalities
Gorriz, J M, Group, SiPBA, neuroscience, CAM
In the 70s a novel branch of statistics emerged focusing its effort in selecting a function in the pattern recognition problem, which fulfils a definite relationship between the quality of the approximation and its complexity. These data-driven approaches are mainly devoted to problems of estimating dependencies with limited sample sizes and comprise all the empirical out-of sample generalization approaches, e.g. cross validation (CV) approaches. Although the latter are \emph{not designed for testing competing hypothesis or comparing different models} in neuroimaging, there are a number of theoretical developments within this theory which could be employed to derive a Statistical Agnostic (non-parametric) Mapping (SAM) at voxel or multi-voxel level. Moreover, SAMs could relieve i) the problem of instability in limited sample sizes when estimating the actual risk via the CV approaches, e.g. large error bars, and provide ii) an alternative way of Family-wise-error (FWE) corrected p-value maps in inferential statistics for hypothesis testing. In this sense, we propose a novel framework in neuroimaging based on concentration inequalities, which results in (i) a rigorous development for model validation with a small sample/dimension ratio, and (ii) a less-conservative procedure than FWE p-value correction, to determine the brain significance maps from the inferences made using small upper bounds of the actual risk.
Comparative Analysis of Predictive Methods for Early Assessment of Compliance with Continuous Positive Airway Pressure Therapy
Rafael-Palou, Xavier, Turino, Cecilia, Steblin, Alexander, Sánchez-de-la-Torre, Manuel, Barbé, Ferran, Vargiu, Eloisa
Patients suffering from obstructive sleep apnea are mainly treated with continuous positive airway pressure (CPAP). Good compliance with this therapy is broadly accepted as more than 4h of CPAP average use nightly. Although it is a highly effective treatment, compliance with this therapy is problematic to achieve with serious consequences for the patients' health. Previous works already reported factors significantly related to compliance with the therapy. However, further research is still required to support clinicians to early anticipate patients' therapy compliance. This work intends to take a further step in this direction by building compliance classifiers with CPAP therapy at three different moments of the patient follow-up (i.e. before the therapy starts and at months 1 and 3 after the baseline). Results of the clinical trial confirmed that month 3 was the time-point with the most accurate classifier reaching an f1-score of 87% and 84% in cross-validation and test. At month 1, performances were almost as high as in month 3 with 82% and 84% of f1-score. At baseline, where no information about patients' CPAP use was given yet, the best classifier achieved 73% and 76% of f1-score in cross-validation and test set respectively. Subsequent analyses carried out with the best classifiers of each time point revealed that certain baseline factors (i.e. headaches, psychological symptoms, arterial hypertension and EuroQol visual analogue scale) were closely related to the prediction of compliance independently of the time-point. In addition, among the variables taken only during the follow-up of the patients, Epworth and the average nighttime hours were the most important to predict compliance with CPAP.
The Application of Machine Learning Techniques for Predicting Results in Team Sport: A Review
Over the past two decades, Machine Learning (ML) techniques have been increasingly utilized for the purpose of predicting outcomes in sport. In this paper, we provide a review of studies that have used ML for predicting results in team sport, covering studies from 1996 to 2019. We sought to answer five key research questions while extensively surveying papers in this field. This paper offers insights into which ML algorithms have tended to be used in this field, as well as those that are beginning to emerge with successful outcomes. Our research highlights defining characteristics of successful studies and identifies robust strategies for evaluating accuracy results in this application domain. Our study considers accuracies that have been achieved across different sports and explores the notion that outcomes of some team sports could be inherently more difficult to predict than others. Finally, our study uncovers common themes of future research directions across all surveyed papers, looking for gaps and opportunities, while proposing recommendations for future researchers in this domain.
iPromoter-BnCNN: a Novel Branched CNN Based Predictor for Identifying and Classifying Sigma Promoters
Amin, Ruhul, Rahman, Chowdhury Rafeed, Sifat, Md. Habibur Rahman, Liton, Md Nazmul Khan, Rahman, Md. Moshiur, Shatabda, Swakkhar, Ahmed, Sajid
Promoter is a short region of DNA which is responsible for initiating transcription of specific genes. Development of computational tools for automatic identification of promoters is in high demand. According to the difference of functions, promoters can be of different types. Promoters may have both intra and inter class variation and similarity in terms of consensus sequences. Accurate classification of various types of sigma promoters still remains a challenge. We present iPromoter-BnCNN for identification and accurate classification of six types of promoters - sigma24, sigma28, sigma32, sigma38, sigma54, sigma70. It is a Convolutional Neural Network (CNN) based classifier which combines local features related to monomer nucleotide sequence, trimer nucleotide sequence, dimer structural properties and trimer structural properties through the use of parallel branching. We conducted experiments on a benchmark dataset and compared with two state-of-the-art tools to show our supremacy on 5-fold cross-validation. Moreover, we tested our classifier on an independent test dataset. Our proposed tool iPromoter-BnCNN along with the source code is freely available at https://cutt.ly/te6XISV.
Evaluating Classification Models, Part 3
This series differs from other discussions of evaluation metrics for classification models in that it aims to provide a systematic perspective. Rather than providing a laundry list of individual metrics, it situates those metrics within a fairly comprehensive family and explains how you can choose a member of that family that is appropriate for your use case. This post explains how the three weighted "Pythagorean means" (arithmetic, geometric, and harmonic) of precision and recall encode preferences over models. Suppose we build two different models, and one has better precision while the other has better recall. To choose between these models, we need to decide whether the gain from 90.8% precision to 91.5% precision that we get by going from Model A to Model B is enough to offset a loss from 99% recall to 97% recall.
Have Unbalanced Classes? Try Significant Terms
The words that are significant to a class can be used improve the precision-recall trade off in classification. And it is tougher (sorry Yogi!) when the target classes to predict have widely varying supports. But that does happen often with real world datasets. Case in point is the prediction of a near future CCU readmission of a patient based on a discharge note. Only a small fraction of patients get readmitted to CCU within 30 days of a discharge. Our analysis of MIMIC-III dataset in the previous post showed that over 93% of the patients did not require readmission.
A US government study confirms most face recognition systems are racist
Almost 200 face recognition algorithms--a majority in the industry--had worse performance on nonwhite faces, according to a landmark study. What they tested: The US National Institute of Standards and Technology (NIST) tested every algorithm on two of the most common tasks for face recognition. The first, known as "one-to-one" matching, involves matching a photo of someone to another photo of the same person in a database. This is used to unlock smartphones or check passports, for example. The second, known as "one-to-many" searching, involves determining whether a photo of someone has any match in a database.
Machine learning and its applications in plant molecular studies
The advent of high-throughput genomic technologies has resulted in the accumulation of massive amounts of genomic information. However, biologists are challenged with how to effectively analyze these data. Machine learning can provide tools for better and more efficient data analysis. Unfortunately, because many plant biologists are unfamiliar with machine learning, its application in plant molecular studies has been restricted to a few species and a limited set of algorithms. Thus, in this study, we provide the basic steps for developing machine learning frameworks and present a comprehensive overview of machine learning algorithms and various evaluation metrics. Furthermore, we introduce sources of important curated plant genomic data and R packages to enable plant biologists to easily and quickly apply appropriate machine learning algorithms in their research. Finally, we discuss current applications of machine learning algorithms for identifying various genes related to resistance to biotic and abiotic stress. Broad application of machine learning and the accumulation of plant sequencing data will advance plant molecular studies. The advent of high-throughput sequencing technologies has produced several large-scale data sets. This enormous amount of information enables biologists to explore topics that were once difficult or impossible to investigate, such as associations between microRNA and certain diseases, the causes of vascular inflammation and atherosclerosis in humans [1–3] and stress breeding in plants [4]. However, many challenges have also emerged. For example, the European Bioinformatics Institute now stores 273 petabytes of raw molecular data on humans, plants and animals (https://www.ebi.ac.uk/).
On Sharing Models Instead of Data using Mimic learning for Smart Health Applications
Baza, Mohamed, Salazar, Andrew, Mahmoud, Mohamed, Abdallah, Mohamed, Akkaya, Kemal
On Sharing Models Instead of Data using Mimic learning for Smart Health Applications Mohamed Baza, Andrew Salazar †, Mohamed Mahmoud, Mohamed Abdallah ‡, Kemal Akkaya ‡ Department of Computer Science, Tennessee Tech University, Cookeville, TN, USA ‡ Department of Information and Decision Sciences, California State San Bernardino, San Bernardino, CA, USA ‡ division of Information and Computing Technology, College of Science and Engineering, HBKU, Doha, Qatar § Department of Electrical and Computer Engineering, Florida International University, Miami, FL, USA Abstract --Electronic health records (EHR) systems contain vast amounts of medical information about patients. These data can be used to train machine learning models that can predict health status, as well as to help prevent future diseases or disabilities. However, getting patients' medical data to obtain well-trained machine learning models is a challenging task. This is because sharing the patients' medical records is prohibited by law in most countries due to patients privacy concerns. In this paper, we tackle this problem by sharing the models instead of the original sensitive data by using the mimic learning approach. The idea is first to train a model on the original sensitive data, called the teacher model. Then, using this model, we can transfer its knowledge to another model, called the student model, without the need to learn the original data used in training the teacher model.
A Study of the Learnability of Relational Properties (Model Counting Meets Machine Learning)
Usman, Muhammad, Wang, Wenxi, Wang, Kaiyuan, Vasic, Marko, Vikalo, Haris, Khurshid, Sarfraz
Relational properties, e.g., the connectivity structure of nodes in a distributed system, have many applications in software design and analysis. However, such properties often have to be written manually, which can be costly and error-prone. This paper introduces the MCML approach for empirically studying the learnability of a key class of such properties that can be expressed in the well-known software design language Alloy. A key novelty of MCML is quantification of the performance of and semantic differences among trained machine learning (ML) models, specifically decision trees, with respect to entire input spaces (up to a bound on the input size), and not just for given training and test datasets (as is the common practice). MCML reduces the quantification problems to the classic complexity theory problem of model counting, and employs state-of-the-art approximate and exact model counters for high efficiency. The results show that relatively simple ML models can achieve surprisingly high performance (accuracy and F1 score) at learning relational properties when evaluated in the common setting of using training and test datasets -- even when the training dataset is much smaller than the test dataset -- indicating the seeming simplicity of learning these properties. However, the use of MCML metrics based on model counting shows that the performance can degrade substantially when tested against the whole (bounded) input space, indicating the high complexity of precisely learning these properties, and the usefulness of model counting in quantifying the true accuracy.