South America
My Journey into Deep Learning
I come from physics and computer engineering. I studied both in Venezuela, and then I did a Master in Physics in Mexico. But I consider myself a Data Scientist. So even though I have a good and extensive background in math, calculus and statistics, it was not easy to get started with machine learning and then deep learning. This subjects are not new, but the way we study them, how we build software and solutions that use them, and also the way we program or interact with them has changed dramatically.
Meet the Company Trying to Democratize Clinical Trials With AI
A decade ago, Pablo Graiver was working as a VP at Kayak, the online airfare aggregator, when he sat down to dinner with an old friend--a heart surgeon from his home country of Argentina. The talk turned to how tech was doing more to save folks a few bucks on a flight to Rome than to save people's lives. Right now, the US has exactly 19,816 clinical trials open and ready to recruit patients--trials of promising new therapeutics to fight everything from HIV to cancer to Alzheimer's. About 18,000 of them will get stuck on the tarmac because they won't get enough people enrolled. And a third of those will never get off the ground at all, for the same reason. So where are all the patients?
How linguistic descriptions of data can help to the teaching-learning process in higher education, case of study: artificial intelligence
Rubio-Manzano, Clemente, Senoceain, Tomas Lermanda
Artificial Intelligence is a central topic in the computer science curriculum. From the year 2011 a project-based learning methodology based on computer games has been designed and implemented into the intelligence artificial course at the University of the Bio-Bio. The project aims to develop software-controlled agents (bots) which are programmed by using heuristic algorithms seen during the course. This methodology allows us to obtain good learning results, however several challenges have been founded during its implementation. In this paper we show how linguistic descriptions of data can help to provide students and teachers with technical and personalized feedback about the learned algorithms. Algorithm behavior profile and a new Turing test for computer games bots based on linguistic modelling of complex phenomena are also proposed in order to deal with such challenges. In order to show and explore the possibilities of this new technology, a web platform has been designed and implemented by one of authors and its incorporation in the process of assessment allows us to improve the teaching learning process.
Cardiac Arrhythmia Detection from ECG Combining Convolutional and Long Short-Term Memory Networks
Warrick, Philip, Homsi, Masun Nabhan
Objectives: Atrial fibrillation (AF) is a common heart rhythm disorder associated with deadly and debilitating consequences including heart failure, stroke, poor mental health, reduced quality of life and death. Having an automatic system that diagnoses various types of cardiac arrhythmias would assist cardiologists to initiate appropriate preventive measures and to improve the analysis of cardiac disease. To this end, this paper introduces a new approach to detect and classify automatically cardiac arrhythmias in electrocardiograms (ECG) recordings. Methods: The proposed approach used a combination of Convolution Neural Networks (CNNs) and a sequence of Long Short-Term Memory (LSTM) units, with pooling, dropout and normalization techniques to improve their accuracy. The network predicted a classification at every 18th input sample and we selected the final prediction for classification. Results were cross-validated on the Physionet Challenge 2017 training dataset, which contains 8,528 single lead ECG recordings lasting from 9s to just over 60s. Results: Using the proposed structure and no explicit feature selection, 10-fold stratified cross-validation gave an overall F-measure of 0.83.10 0.015 on the held-out test data (mean standard deviation over all folds) and 0.80 on the hidden dataset of the Challenge entry server.
Machine learning for graph-based representations of three-dimensional discrete fracture networks
Valera, Manuel, Guo, Zhengyang, Kelly, Priscilla, Matz, Sean, Cantu, Vito Adrian, Percus, Allon G., Hyman, Jeffrey D., Srinivasan, Gowri, Viswanathan, Hari S.
Structural and topological information play a key role in modeling flow and transport through fractured rock in the subsurface. Discrete fracture network (DFN) computational suites such as dfnWorks are designed to simulate flow and transport in such porous media. Flow and transport calculations reveal that a small backbone of fractures exists, where most flow and transport occurs. Restricting the flowing fracture network to this backbone provides a significant reduction in the network's effective size. However, the particle tracking simulations needed to determine the reduction are computationally intensive. Such methods may be impractical for large systems or for robust uncertainty quantification of fracture networks, where thousands of forward simulations are needed to bound system behavior. In this paper, we develop an alternative network reduction approach to characterizing transport in DFNs, by combining graph theoretical and machine learning methods. We consider a graph representation where nodes signify fractures and edges denote their intersections. Using random forest and support vector machines, we rapidly identify a subnetwork that captures the flow patterns of the full DFN, based primarily on node centrality features in the graph. Our supervised learning techniques train on particle-tracking backbone paths found by dfnWorks, but run in negligible time compared to those simulations. We find that our predictions can reduce the network to approximately 20% of its original size, while still generating breakthrough curves consistent with those of the original network.
[N] Postdoctoral positions in machine learning for neuroimaging • r/MachineLearning
Dear colleagues, We are looking for two Postdoctoral Research Associates with a background in electrical engineering, physics, statistics or computer science to work on a research project involving the application of machine learning methods to structural Magnetic Resonance Imaging data. The project is a collaboration between King's College London, UK (Dr. Vince Calhoun) and the Universidade Federal do ABC, Brazil (Prof João Sato). The post holders will be based at the Institute of Psychiatry, Psychology & Neuroscience (King's College London). I would be happy to answer any queries from prospective applicants.
Bisimulations on Data Graphs
Abriola, Sergio, Barceló, Pablo, Figueira, Diego, Figueira, Santiago
Bisimulation provides structural conditions to characterize indistinguishability from an external observer between nodes on labeled graphs. It is a fundamental notion used in many areas, such as verification, graph-structured databases, and constraint satisfaction. However, several current applications use graphs where nodes also contain data (the so called "data graphs"), and where observers can test for equality or inequality of data values (e.g., asking the attribute 'name' of a node to be different from that of all its neighbors). The present work constitutes a first investigation of "data aware" bisimulations on data graphs. We study the problem of computing such bisimulations, based on the observational indistinguishability for XPath ---a language that extends modal logics like PDL with tests for data equality--- with and without transitive closure operators. We show that in general the problem is PSpace-complete, but identify several restrictions that yield better complexity bounds (coNP, PTime) by controlling suitable parameters of the problem, namely the amount of non-locality allowed, and the class of models considered (graphs, DAGs, trees). In particular, this analysis yields a hierarchy of tractable fragments.
AI fake porn could cast any of us
In the case of revenge porn, people often ask: If the photos weren't taken in the first place, how could ex-partners, or hackers who steal nude photos, post them? We are now in the age of fake porn. Fake, as in, famous people's faces – or, for that matter, anybody's face – near-seamlessly stitched onto porn videos. As Motherboard reports, you can now find actress Jessica Alba's face on porn performer Melanie Rios' body, actress Daisy Ridley's face on another porn performer's body and Emma Watson's face on an actress's nude body, all on Celeb Jihad – a celebrity porn site that regularly posts celebrity nudes, including stolen/hacked ones. The word "appears" is key.
A Solution to Time-Varying Markov Decision Processes
Liu, Lantao, Sukhatme, Gaurav S.
We consider a decision-making problem where the environment varies both in space and time. Such problems arise naturally when considering e.g., the navigation of an underwater robot amidst ocean currents or the navigation of an aerial vehicle in wind. To model such spatiotemporal variation, we extend the standard Markov Decision Process (MDP) to a new framework called the Time-Varying Markov Decision Process (TVMDP). The TVMDP has a time-varying state transition model and transforms the standard MDP that considers only immediate and static uncertainty descriptions of state transitions, to a framework that is able to adapt to future time-varying transition dynamics over some horizon. We show how to solve a TVMDP via a redesign of the MDP value propagation mechanisms by incorporating the introduced dynamics along the temporal dimension. We validate our framework in a marine robotics navigation setting using spatiotemporal ocean data and show that it outperforms prior efforts.
AI 'scientist' finds that toothpaste ingredient may help fight drug-resistant malaria
When a mosquito infected with malaria parasites bites someone, it transfers the parasites into their bloodstream via its saliva. These parasites work their way into the liver, where they mature and reproduce. After a few days, the parasites leave the liver and hijack red blood cells, where they continue to multiply, spreading around the body and causing symptoms, including potentially life-threatening complications. Malaria kills over half a million people each year, predominantly in Africa and south-east Asia. While a number of medicines are used to treat the disease, malaria parasites are growing increasingly resistant to these drugs, raising the spectre of untreatable malaria in the future.